Building species It begins with a mental choice of the position of the part before the planes of projections. Then choose the number of types required and sufficient to detect the detail form, as well as the method of their construction.

The choice of partition position in the system of projections of projections depends on its working position, the method of manufacturing in production, forms. For example, if the item is made on the lathe, then the drawing of the rotation axis should be placed horizontally.

Drawing types can be performed different ways. Consider some of them.

Construction of sequential drawing geometric telconstituting the form of the subject. In order to perform the drawing in this way, it is necessary to mentally divide the item to the components of its simple geometric bodies, finding out how they are relative to each other. Then you need to choose the main type of detail and the number of images that allow you to understand its shape and sequentially depict one geometric body after another until the object shape is completely displayed. It is necessary to observe the size of the form and correctly orient its elements relative to each other (Table 8).

The construction of species on the basis of the elementary drawing of the geometric bodies that constitute the form of the subject is carried out using reception and increment techniques.

When drawing a geometric body using receipt reception, the shape of the workpiece is sequentially changed in the drawing using the removal of volumes similar to the receptions of its processing, drilling, milling, etc.

When drawing a geometric body using the reception of increment, the volume of product elements seems to complement each other, grow up.

8. The elemental drawing of the geometric bodies constituting the form of the subject

Building species using a constant line drawing (method of external coordination). A constant direct drawing is called a line, which is carried out from the center of coordinates (points O) down to the right at an angle of 45 ° (Fig. 86).

The subject is mentally placed in the system of projections planes. The axes of the planners of projections are taken for coordinate axes. The projection relationship between the top view and the view of the left is carried out using the projection lines, which are carried out before the intersection with a constant direct drawing and build at an angle of 90 ° to each other.

A constant direct drawing is usually used in cases where the third type of detail must be constructed on two specified species (see Fig. 86). Listing two types of details, build a constant direct drawing and conduct the projection lines parallel to the axis oxo before the intersection with a constant line drawing, and then parallel to the OZ axis.

The considered method of construct is called the external coordination method, since the subject is fixed in space relative to the axes of the projectors of the projections, which are located outside the object depicted.

(If the drawing does not show the axis of the projections and it is necessary to perform the third type of detail, you can build a constant direct drawing anywhere on the right side of the top view.)

Building species using the internal coordination of the object. Internal coordination consists in the mental administration of additional axes of coordinates tied to the projected subject.

Fig. 86. Building a third projection by two specified with a constant direct drawing

Fig. 87. Building species in the method of internal coordination of the object

13.1. Method for building images based on the analysis of the form of the subject.As you already know, most items can be represented as a combination of geometric bodies. Consequently, to read and perform the drawings, you need to know how these geometric bodies are depicted.

Now that you know how such geometric bodies are depicted in the drawing, and learned how the peaks, Rear Ra and the Edge are projected, it will be easier for you to read the drawings of items.

Fig. 100. Projections of details

Figure 100 shows part of the car - counterweight. Let's analyze his shape. What are your known geometric bodies you can share it? To answer this question, remember characteristic signsinherent images of them geometric bodies.

In Figure 101, and one of them is highlighted with a conditionally brown-in-color. What geometric body has such projections?

Projections in the form of rectangles are characteristic of parallelepiped. Three projections and a visual image of parallelepipeda isolated in Figure 101, I am brown, given in Figure 101, b.

Figure 101, in gray Conditionally, another geometric body is allocated. What geometric body has such projections?

With such projections, you met when considering the images of a triangular prism. Three projections and a visual image of the prism isolated in gray in Figure 101, B, are given in Figure 101, thus, the counterweight consists of a rectangular parallelepiped and a triangular prism.

But from the parallelepiped, a part is removed inside brown bar lines and circles in Figure 101, D. What geometric body has such projections?

With the projections in the form of a circle and two rectangles you met when considering the images of the cylinder. Therefore, the counterweight contains a hole having a cylinder form, three projections and a visual image of which are given in Figure 101, e.

An analysis of the form of the subject is necessary not only when reading, software and when performing the drawings. So, by defining, the form of which geometric bodies have a counterweight portion shown in Figure 100, you can establish an expedient sequence of building its drawing.

For example, the drawing of the counterweight is built as:
1) on all types of drawing parallelepiped, which is the basis of a counterweight;
2) a triangular prism is added to the parallelepiped;
3) draw the element in the form of a cylinder. On the views from above and on the left, it is shown by stroke lines, since the open-I is not invisible.

Fig. 101. Detail form analysis

30. Draw a detail in description, called a sleeve. It consists of a truncated cone and the correct quadrangular prism. The diameter of one base of the cone is 30 mm, the other is 50 mm, the height of the truncated cone is 50 mm. Prism is attached to a greater base of the cone, which is located in the middle of its base of 50 x 50 mm. The height of the prism is 10 mm. Along the axis of the sleeve drilled through a cylindrical hole 0 20 mm. The axis of the bushings perpendicular to the profile plane of projections.

13.2. Sequence of building species in the drawing of the part.
Consider an example of building species of details - supports (Fig. 102).

Fig. 102. Visual image of support

Before proceeding to building images, it is necessary to clearly present the general initial geometric shape of the de-Gali (whether it is a cube, cylinder, parallelepiped or other). This form must be borne in mind when building species.

The general form of the subject shown in Figure 102 is rectangular parallelepiped. It has rectangular cuts and cutout in the form of a triangular prism. Picture a detail will begin with its general form - parallelepiped (Fig. 103. a).
Sprogating parallelepiped on the plane V, N, W, we obtain rectangles on all three planes of projections. On the frontal plane of the projections, the height and length of the details will be praised, i.e. dimensions 30 and 34. On the horizontal plane of the projections - the width and length of the part, i.e. dimensions 26 and 34. On the profile - width and height, i.e. sizes 26 and 30.

Each measurement of parts is shown without distortion twice: W, cat - on frontal and profile planes, lazy to frontal and horizontal planes, width - on the horizontal and profile planes of projections. However, dads to apply the same size in the drawing can not be.

All construction will be performed first with thin lines. Since the main type and top view is symmetrical, they are applied to the axis of symmetry.

Now we show on the projections of parallelepiped cuts (Fig. 103, b). It is more expedient to show first on the main form. To do this, it is necessary to postpone 12 mm left and right from the symmetry axis and spend vertical lines through the obtained points. Then at a distance of 14 mm from the top edge of the part to spend the cuts of horizontal straight lines.

Fig. 103. Sequence of building species

We construct the projections of these cuts on other types. This can be done using communication lines. After that, on tops and left, you need to show segments that limit cutting projections.

In conclusion, the images set as lines set by the standard and cause dimensions (Fig. 103, B).

1. Name the sequence of actions that make up the process of building species of the subject.
2. What purpose are the objects of projection links?

13.3. Building cutouts on geometric bodies. On the
figure 104 shows the images of geometric bodies, the shape of which is complicated by various kinds of cutouts.

Details of such a form are widespread in the technique. To draw or read their drawing, it is necessary to submit the shape of the workpiece from which the part is obtained and the shape of the cutout. Consider examples.

Fig. 104. Geometric bodies containing cuts

Fig. 105. Analysis of the laying form

Example 1. In Figure 105, the drawing of the gasket is given. What form has a remote part? What was the form of the workpiece?
After analyzing the drawing of the gasket, one can come to the conclusion that it turned out as a result. Attachments from a rectangular parallelepiped (billets) of the fourth part of the cylinder.

Fig. 106. Building projections of a cut-out

Example 2. Figure 106, and a test tube drawing. What is the form of her workpiece? As a result, the form formed the form?

After analyzing the drawing, it can be concluded that the item is made of a cylindrical billet. It makes a neckline, the form of which is clear from Figure 106, b.

And how to build a cut-out projection on the side of the left?

First depict the rectangle - the type of cylinder on the left ,. Theorest source form of the part. Then building a cut design "Its dimensions are known, therefore, points a", b "and a, b, defining the design projections, can be considered as specified.

Building profile projections A ", L" of these points is shown by the arrow link lines (Fig. 106, B).

By setting the shape of the cutout, it is easy to decide which lines on the form of the left should be cut into solid thick basic, which dash lines, and which remove at all.

Fig. 107. Tasks for exercises

31. Consider the images in Figure 107 and determine which form parts are removed from blanks to get parts. Perform technical drawings of these parts.
32. Build the missing projection of points, lines and cutouts, asked as a teacher in the drawings that you have completed.

13.4. Building a third type.
We will sometimes have to perform the tasks in which you need to build the third available species.

Fig. 108. Brous drawing with cutout

In Figure 108, you see the image of a bar with a neckline. Two types are given: front and top. It is required to build a view of the left. To do this, you must first submit the picture form. Comparison on drawing, we conclude that the bar has the form of a parallelepiped with a size of 10 x 35 x 20 mm. In parallelepiped a cut rectangular shape, its size is 12 x 12 x 10 mm.

The view of the left, as you know, is placed at one height with the main view to the right of it. We carry out one horizontal line at the level of the lower base of the parallelepiped, and the other is at the level of the upper base (Fig. 109, a). These lines limit the height of the view to the left. In any place between them spend a vertical line. It will be a projection of the rear face of Bruck on the profile plane of projections. From it to the right to postpone the segment of 20 mm, i.e. we will restrict the width of the bar, and we will carry out another vertical line - the projection of the front face (Fig. 109.6).

We will now show on the bottom of the left cutout into the details. To do this, postpone the left of the right vertical line, which is the projection of the front edge of the bar, a segment of 12 mm and will carry out another vertical line (Fig. 109, B). After that, we remove all the auxiliary lines of construction and supply the drawing (Fig. 109, d).

Fig. 109. Building a third projection

The third projection can be built on the basis of analysis. geometric shape subject. Consider how it is done. Figure 110, and two projections of the part are given. We must build a third.

Fig. 10. Building a third projection in two data

Judging by these projections, the detail is composed of a hexagonal prism, a parallelepiped and cylinder. Mentally combining them into a one way, present the form of the part (Fig. 110, c).

We carry out on the drawing at an angle of 45 ° auxiliary direct and proceed to building a third projection. What the third projections of a hexagonal prism, a parallelepiped and cylinder look like, you know. Draw a consistently third projection of each of these bodies, using communication lines and axes of symmetry (Fig. 110, b).

Note that in many cases there is no need to build a third projection in the drawing, since the rational implementation of images involves the construction of only the necessary (minimum) quantity of species sufficient to detect the form of the subject. In this case, the construction of the third projection of the subject is only an educational task.

1. You familiarized themselves different ways Building a third projection of the subject. What do they differ from each other?
2. What is the purpose of the constant straight line? How is it carried out?

33. On the drawing of the part (Fig. 111, a) is not a subsidiary of the left - it does not show images of a semicircular cutout and rectangular hole. On the instructions of the teacher, turn over or transfer the drawing to the tracker and add it missing lines. What lines (solid basic or bar) do you use for this purpose? Spend the missing lines also in Figures 111, B, B, G

34. List or transfer data to the traction in Figure 112 of the projection and build profile projections of parts.
35. List or transfer to the traction of the projections shown in Figure 113 or 114 by the teacher. Build missing projections at the site of question marks. Perform technical drawings of parts.

Building a third type of two known species.

Let them know the main look and top view. It is necessary to build a view of the left.

For the construction of a third type of two known two main methods are used.

Building a third type with auxiliary straight.

In order to move the size of the width of the part from the top view on the left side view, it is convenient to use auxiliary straight (Fig. 27a, b). This direct is more convenient to spend on the right from the top view at the angle of 45 ° to the horizontal direction.

To build a third projection And 3. Vershins BUT, spend through its front projection A 2. horizontal straight 1 . It will be the desired projection on it. And 3.. After that, through a horizontal projection A 1. Hold horizontal straight 2 before crossing it with auxiliary direct at the point A 0.. Through the point A 0. Let's spend the vertical straight 3 before intersection with a straight 1 In the desired point And 3..

The profile projections of the remaining vertices of the subject are similar.

After an auxiliary straight line at an angle of 45 o, the construction of a third projection is also convenient to perform with the help of a pilot and a triangle (Fig. 27b). Initially through the front projection A 2. Cut the horizontal direct. Spend horizontal direct through the projection A 1.no need, enough, putting a ray, make a horizontal spot at the point A 0. on auxiliary straight After that, slightly shifting the reiser down, we apply the cooler with one cathe to the flight so that the second cattet passes through the point A 0., and note the position of the profile projection And 3..

Building a third type with basic lines.

To build a third type, it is necessary to determine which drawing lines it is advisable to take for the basic sizes of the sizes of the subject. As such lines are usually taken axial lines (projections of the planes of the subject symmetry) and the projection of the base planes of the subject. We will analyze on the example (Fig. 28) Building a view of the left in two data Projects of the subject.

Fig. 27 Building a third projection in two data

Fig. 28. The second way to build a third projection in two data

Comparing both images, we establish that the surface of the subject includes surfaces: proper hexagonal 1 and quadhugonal 2 Prism, two cylinders 3 and 4 and truncated cone 5 . The subject has a frontal plane of symmetry F.which is convenient for the database of the size of the size of the width of individual parts of the subject when it is built on the left. The heights of individual areas of the subject are counted from the lower base of the subject and are controlled by horizontal communication lines.

The form of many objects is complicated by various cuts, cutouts, intersection of the components. Then it is previously necessary to determine the form of the intersection lines, to build them at individual points, introducing the designations of the projections of points, which, after the construction, can be removed from the drawing.

In fig. 29 The view of the left of the item is constructed, the surface of which is formed by the surface of the vertical cylinder of rotation with T.-the cutout in its upper part and the cylindrical hole occupying the front-scale-projection position. As basic planes, the plane of the lower base and the front plane of symmetry are taken F.. Picture T.- The cutout on the side of the left is built using points A, B, C, D and E.cutout circuit, and the line intersection of cylindrical surfaces - with the help of points K, L, M And they are symmetrical. When constructing a third type, the symmetry of the subject relative to the plane F..

Fig. 29. Building a view of the left

5.2.3. Construction of transition lines. Many parts contain lines of intersection of all sorts of geometric surfaces. These lines are called transition lines. In fig. 30 shows the bearing cover, the surface of which is limited to the surfaces of rotation: conical and cylindrical.

The intersection line is based using auxiliary sectional planes (see section 4).

The characteristic points of the intersection line are determined.

Full technical drawing Contains at least three projections. However, knowledge to imagine an object for two projections is required both from the technologist and from a qualified worker. It is in examines in exam tickets in technical universities and colleges there are continuously for the construction of a third type of two specified. In order to fully fulfill the similar task, you need to know legendAdopted in technical drawing.

You will need

• - paper;
• - 2 projections of the part;
• - Drawing tools.

Instruction

1. Theses of the construction of a third type are identical for the classic drawing, drawing up the sketch and the construction of the drawing in one of the pre-prepared for this computer programs. Previously, everyone is analyzing the specified projections. See what kinds of types are given to you. When it comes to 3 species, this is a common projection, top view and view of the left. Determine what is given to you. Make it is permitted by the location of the drawings. The view of the left is located on the right side of the total, and the top view is under it.

2. Install projection links with one of specified species. Make it is permitted, extending horizontal lines that limit the silhouette of the subject to the right when it is required to build a view of the left. If we are talking about the top view, continue down vertical lines. In any case, one of the parameters of the details on your drawing will appear mechanically.

3. Discover on existing projections 2nd parameter limiting the silhouettes of the part. When building a view to the left, this size you will find on top view. When establishing a projection connection with the main type, the height of the part appeared in the drawing. So, from the view from above it is necessary to take a width. When constructing a view from above, the 2nd size is taken with a side projection. Indicate the silhouettes of your object in the third projection.

4. Look, whether the detail of the protrusions, emptiness, holes. This is all noticed on a common projection, which by definition should give the most accurate idea of \u200b\u200bthe subject. It is also true as in determining the universal silhouette of the part in the third projection, establish a projection link between different elements. The remaining parameters (say, the distance from the center of the hole to the edge of the part, the depth of the protrusion, etc.) Detected on the side view either from above. Build need-free elements, considering the measurements you discovered.

5. In order to check how true you coped with the task, try drawing a detail in one of the axonometric projections. Look at how reasonfully the elements of the third type on the bulk projection are located. Dieuz can be that they will have to make some adjustments to the drawing. Poggle Check your construction can also draw a perspective

One of the most interesting tasks of designed geometry - the construction of the third view for given 2. It requires a thoughtful approach and the petty measurement of distances, it is not consistently represented from the first time. However, if the recommended sequence of actions is scrupulously followed, build the 3rd view is absolutely permissible, even without spatial imagination.

You will need

• - paper;
• - pencil;
• - Rule or Circle.

Instruction

1. First try on two available view m Determine the form of individual parts of the depicted item. If a triangle is depicted on top, then it may be a triangular prism, a rotational cone, a triangular or quadrangular pyramid. The form of a quadrangle can take a cylinder, quadrangular or triangular prism or other items. The image in the form of a circle can designate a bowl, cone, cylinder or other surfaces of rotation. So either by contrast, try to present the universal form of the subject in the aggregate.

2. Alsae the boundaries of the planes, for the comfort of lines. Start the transfer from the most comfortable and intelligible element. Take all the point you are right "see" on both view X and transfer it to the 3rd view. To do this, omit perpendicular to the boundaries of the planes and continue it on the further plane. At the same time, keep in mind that when moving from view On the left side of the top view (or on the contrary), you need to use a circulation or measured the distance using a ruler. Thus, on the site of your third view Two straight lines will intersect. This will be the projection of the selected point on the 3rd view. In the same way, it is allowed to transfer how much preferably points until you become a distinct universal kind of detail.

3. Check that the construction is correct. To do this, measure the dimensions of those parts parts that are reflected entirely (say, the standing cylinder will be one "growth" on the form of the left and view in front). In order to realize, if you did not forget anything, try to look at the front view from the position of the observer on top and recalculate (it would be approximately approximately) how much the boundaries of the holes and surfaces should be visible. All straight, every point is required to reflect on all view x. If the item is symmetrical, do not forget to notice the axis of symmetry and check the equality of both parts.

4. Remove all auxiliary lines, check, so that all noticeable lines were notified by the dotted line.

In order to portray the same item, first depict it separate elements In the form of the simplest figures, and after that their projection is performed. The construction of the projection is quite often used in the descriptive geometry.

You will need

• - pencil;
• - Circle;
• - line;
• - Handbook "Design Geometry";
• - rubber.

Instruction

1. Thoughtfully read the data of the task: for example, the total projection F2 is given. The point F belonging to it is located on the side surface of the rotation cylinder. The construction of 3 projections of the point F is required. Mentally imagine how all this should look, later than what is proceeding to building an image on paper.

2. The rotational cylinder can be represented as a rotating rectangle, one side of which is accepted for the axis of rotation. The second side of the rectangle is the opposite axis of rotation - forms the side surface of the cylinder. The remaining two sides represent the lower and top base of the cylinder.

3. Due to the fact that the surface of the rotation cylinder when constructing the given projections is performed as a horizontal-projection surface, the projection of the point F1 must certainly be coincided with the point R.

4. Picture the projection of the point F2: from the fact that F is on the overall surface of the rotation cylinder, the point F2 will be distrounded to the lower base point F1.

5. Third projection point f Build with the help of the ordinary axis: set out the F3 on it (this point-projection will be the right of the Z3 axis).

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Note!
During the construction of projections of the image, follow the basic rules used in the design geometry. In dismissal case, the projections will not be able to fulfill.

Helpful advice
In order to build an isometric image, use the upper base of the rotation cylinder. To do this, in the first building an ellipse (it will be placed in the X'o'u plane '). Later, spend the tangent lines and the bottom half-elix. After that, spend the coordinate broken and with its support build the projection of the point F, that is, the point F '.

It is not so much in our time of people who have never been drawn to a draw or draw something on paper. Knowledge to fulfill a primitive drawing of some kind of construction occasionally is somewhat suitable. It is permitted to spend a lot of time, explaining "on the fingers", as the one or the other thing is made, while it is satisfied with one gaze on her drawing, in order to realize it without every words.

You will need

• - Watman Leaf;
• - drawing accessories;
• - Drawing board.

Instruction

1. Choose a sheet format on which the drawing will be performed - in accordance with GOST 9327-60. The format should be like that in order for the sheet was allowed to put the main views details In an appropriate scale, as well as all the desired cuts and sections. For simple parts, the format A4 (210x297 mm) is chosen or A3 (297x420 mm). The 1st can be located in its long side just vertically, 2nd - vertically and horizontally.

2. Draw the drawing frame, retreating from the left edge of the leaf of 20 mm, from the remaining 3 - 5 mm. Draw the main inscription - the table in which all data is entered details and drawing. Its sizes are determined by GOST 2.108-68. The width of the core inscription is constant - 185 mm, height varies from 15 to 55 mm, depending on the designation of the drawing and the type of institution for which it is performed.

3. Select the scale scale. The permissible scales are determined by GOST 2.302-68. They should be preferred as well as all the main elements were interconnected in the drawing details . If at the same time some places are not clearly visible, they are allowed to transfer them separate view, showing with the desired increase.

4. Choose the main image details . It should be such a direction of the gaze to the part (direction of projection), from which its design is disclosed especially. In most cases, the primary image is the location in which the item is on the machine during the execution of the rod operation. Details having an axis of rotation are located on the main image, as usual, so so that the axis had a horizontal location. The main image is located in the top of the drawing on the left (if there are three projections) or close to the center (in the absence of a lateral projection).

5. Determine the location of other images (side view, top, sections, cuts). Views details It is formed by its projection on three or two mutually perpendicular planes (method of monge). In this case, the part should be located in such a way, so that the set or all its elements were projected without distortion. If some of these species is informationally unnecessary, do not execute it. The drawing should have only those images that need.

6. Choose cuts and sections that need to be performed. Their difference from each other is that the section shows and what is behind the securing plane, while in section displays only what is located in the plane itself. The securing plane can be stepped and broken.

7. Let's proceed at ease for drawing. When drawing lines, follow GOST 2.303-68, in which are determined views lines and their parameters. Position apart from each other at such a distance in order to remain pretty space for the size of the sizes. If the plane of the incisions go through monolith details , Stroke section lines going at an angle of 45 °. If the hatch lines coincide with the main lines of the image, allowed to draw them at an angle of 30 ° or 60 °.

8. Disclaim the dimensional lines and sizes. In this case, follow the following rules. The distance from the first dimensional line to the silhouette of the image should be at least 10 mm, the distance between adjacent dimensional lines is at least 7 mm. Arrows are required to have a length of about 5 mm. Writing numbers in accordance with GOST 2.304-68, take their height equal to 3.5-5 mm. Figures Place closer to the middle of the dimensional line (but not on the axis of the image) with some displacement regarding the numbers made on the adjacent dimension lines.

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Performing an accurate drawing repeatedly requires major time spending. Incidentally, in case of urgent need to make some part more often is not drawing, and sketch. It is performed quite rapidly and without the use of drawing tools. It is whole line Sketch requirements must match.

You will need

• - Detail;
• - paper;
• - pencil;
• — measuring tools.

Instruction

1. The sketch must be accurate. There is a person on him, the one that will make a copy of the part should be a presentation as appearance products and about it constructive features. Consequently earlier each observationally lit the subject. Determine the ratio between different parameters. Look, whether there are holes where they are, their size and diameter ratio to universal product size.

2. Determine what kind it will be the main and how exactly it gives the detail. The number of projections depends on this. They can be 2, 3 and more great. From how many projections you need, their location on the sheet depends. It is necessary to proceed from how difficult will the product be.

3. Select Scale. He should be like that in order to the master could easily disassemble even the smallest details.

4. Start building a sketch from centers and axial lines. In the drawings, they are usually designated by a dotted line with points between strokes. Such lines indicate the middle of the part, the center of the hole, etc. They remain on the work drawings.

5. Distribute external details silhouettes. They are denoted by a thick constant line. See definitely convey the size ratio. Apply internal (noticeable) outlines.

6. Perform cuts. This is done true as well as on any other drawing. A solid surface is shaded by oblique lines, empties remain empty.

7. Spend dimensional lines. From the points, the distance between which you want to designate, depart parallel vertical or horizontal strokes. Between them, draw a straight line with arrows at the ends.

8. Measure the item. Specify the length, width, hole diameters and other dimensions needed to accurately perform work. Write sizes on the sketch. If necessary, apply signs indicating methods and qualitates of processing different surfaces Products.

9. The final stage of the work is to fill the stamp. Make it on the product about the product. In technical universities and design organizations there are standards of filling stamps. If you make a sketch for yourself, then allowed to primitively indicate what it is for the item, the material from which it is made. All other data is the one who will make the item should see in your sketch.

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The drawing is used in order to be the one who will pull the item or build a house could get the most accurate idea of \u200b\u200bthe appearance of the object, its structure, the ratio of parts, surface processing methods. One projection for this, as usual, unsatisfactory. On training drawings, three types are performed - the main, on the left and above. For the objects of difficult form, the types of right and rear also use.

You will need

• - Detail;
• - measuring instruments;
• - drawing tools;
• - Computer with AutoCAD.

Instruction

1. The sequence of drawing on the Watman Sheet and in the AutoCAD program is approximately identical. First see the detail. Determine what its angle will give the most accurate idea of \u200b\u200bthe form and functional features. This projection will become its main look.

2. Look, Identically looks like your item, if you look at it on the right and left. Not only the number of projections depends on this, but also their location on the sheet. The view of the left is to the right of the main one, and the appearance of the right - respectively, to the left. At the same time, in a flat projection, they will look like as if they are at ease in front of the eyes of the observer, that is, without monitoring the prospects.

3. Drawing construction methods are identical to all projections. Mentally position the object in the plane system to which you will project it. Analyze the form of the subject. Look, if it is allowed to share it for more primitive parts. Answer the question, in the shape of which body is allowed to fully enter your object of all or every fragment. Imagine how individual parts look like in an orthogonal projection. The plane on which the object is projected when building a view of the left is on the right side of the item itself.

4. Measure the item. Remove the basic parameters, set the ratio between the whole object and its individual parts. Choose a scale and draw the main look.

5. Select the construction method. There are two of them. To fulfill the drawing receipt reception, apply universal silhouettes of the subject, to the one that you look left or right. After that, we gradually begin to remove the volumes, the discharge of the notches, the silhouettes of holes, etc. When receiving increment, one element is first drawn, and then the rest are slowly attached to it. The choice of the method depends primarily on the difficulty of projection. If the item when you gaze on the left either right is clearly pronounced geometric shape A small number of deviations from the harsh shape, it is more comfortable to apply removal reception. If there are many fragments, and the part itself does not enter into some kind of figure, more excellent to push the items to each other. The difficulty of projections of the same detail may be different, investigators and methods are allowed to change.

6. In any case, start building a side view from the bottom and top lines. They are obliged to be on the same tier as the corresponding lines of the main species. This will provide a projection link. Later, apply universal silhouettes of the details or its first fragment. Observe the size ratio.

7. Having drawn universal silhouettes of the side of the side, apply axial lines on it, hatching, etc. Slip dimensions. You are not invariably to sign the projection. If all kinds of details are located on one sheet, only the rear view is signed. The location of the rest of the projections is determined by standards. If the drawing is made on several sheets and one or both side species are not on the sheet on which the main one needs to be signed.

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Helpful advice
When building a side view in AutoCAD or a different drawing program, combine the upper and lower lines of the main and lateral species in the first stage is not strictly. The drawing is allowed to execute according to fragments, and tiers are combined when you begin to prepare it for printing.

The main element in solving graphic tasks in engineering graphics is the drawing. Under the drawing implies a graphic image of objects or their parts. Drawings are performed in strict accordance with the project rules in compliance with the established requirements and conventions. And the rules of image objects or their composite elements The drawings remain the same in all industries and construction.

The image of the object in the drawing should be such that it can be established in the form in general, the shape of its separate surfaces, the combination and the mutual arrangement of its separate surfaces. In other words, the image of the subject should give a complete picture of its form, device, sizes, as well as the material from which the subject is made, and in some cases include information about the methods of manufacturing the subject. The characteristic of the size of the subject in the drawing and its parts are their dimensions that are applied in the drawing. An image of objects in the drawings is executed, as a rule, "on a specified scale.

Images of objects in the drawing must be placed so that it is uniformly filled it. The number of images in the drawing should be sufficient to obtain a complete and unambiguous representation of it. At the same time, the drawing should only be required amount images, it must be minimal, i.e. the drawing must be concise and contain a minimum volume graphic images and text sufficient for free reading drawing, as well as its manufacture and control.

The visible contours of the objects and their faces in the drawings are performed by a solid thick main line. The necessary invisible parts of the subject are performed using bar lines. In the event that the displayed object has permanent or naturally changing cross sections, it is performed in the desired scale and does not fit on the drawing field of the specified format, it can be shown with breaks.

The rules for building images on drawings and drawing up drawings are given and are governed by the complex of the "Unified System Documentation System" (ECCD) standards.

The image in drawings can be performed in various ways. For example, with the help of rectangular (orthogonal) projection, axonometric projections, linear perspective. When performing machine-building drawings in engineering graph, the drawings are performed according to the method of rectangular projection. The rules of the objects of objects, in this case of products, structures or the corresponding components in the drawings are installed GOST 2.305-68.

When building images of objects by rectangular projection, the object is located between the observer and the corresponding plane of the projection. For the main planes of projections, six faces of the cube are taken, within which the item is located (Fig. 1.1.1, a). The faces of 1,2 and 3 correspond to the frontal, horizontal and profile planes of projections. The edges of the cube with the images obtained on them are combined with the drawing plane (Fig. 1.1.1, b). In this case, the facet 6 can be positioned near the face 4.

The image on the frontal plane of projections (on the face 1) is considered the main one. The item has a relatively frontal plane of the projections so that the image gives the most complete picture of the form and size of the subject, has carried the greatest information about it. This image is called the main thing. Depending on its content of the image, objects are divided into species, cuts, sections.

The image of the visible part of the surface of the subject facing the observer is called the view.

GOST 2.305-68 establishes the following name of the main species obtained on the main planes of projections (see Fig. 1.1.1): 7 - Front view (main view); 2 - top view; 3 - view of the left; 4 - view of the right; 5 - bottom view; B - Rear view. In practice, three types are more widely used: front view, top view and view of the left.

The main types are usually located in the projection connection among themselves. In this case, the name of the species in the drawing is not necessary.

If any kind is shifted relative to the main image, its projection bond with the main type is violated, then the type "A" type is performed above this species (Fig. 1.2.1).

The direction of the look should be indicated by the arrow indicated by the same capital letter of the Russian alphabet as in the inscription above the type. The ratio of the dimensions of the arrows indicating the direction of the view must correspond to the figured in Fig. 1.2.2.

If species are in the projection connection between themselves, but are separated by any images or are not located on one sheet, then the "A" type is also performed above them. Additional type is obtained by projection of the item or part of it to an additional plane of projections, not parallel to the main planes (Fig. 1.2.3). Such an image must be performed in the case when any part of the subject is shown without distorting the shape or sizes on the main planes of projections.

An additional plane of projections in this case may be perpendicular to one of the main planes of projections.

When an additional view is located in a direct projection connection with the appropriate primary type, it is not necessary to designate it (Fig. 1.2.3, a). In other cases, additional look should be marked on the drawing of the inscription type "A" (Fig. 1.2.3, b),

and the image associated with an additional type need to put the arrow indicating the direction of the view, with the corresponding lettering designation.

Additional view can be rotated, while maintaining the position taken for this item on the main image. At the same time, you need to add a sign to the inscription (Fig. 1.2.3, B).

The local species is called an image of a separate, limited space of the object (Fig. 1.2.4).

If the local view is located in the direct projection connection with the corresponding images, then it is not denoted. In other cases, local species are designated similarly species, the local view can be limited to the cliff line ("B" in Fig. 1.2.4).

First of all, it is necessary to find out the shape of the individual parts of the surface of the depicted object. To do this, both specified images should be considered simultaneously. It is useful to keep in mind what surfaces correspond to the most common images: triangle, quadrangle, circle, hexagon, etc.

On the top view in the form of a triangle can be depicted (Fig. 1.3.1, a): triangular prism 1, triangular 2 and quadrangular 3 pyramids, the rotation cone 4.

The image in the form of a quadrilateral (square) may be on top view (Fig. 1.3.1, b): cylinder of rotation 6, triangular prism 8, quadrangular prisms 7 and 10, as well as other items bounded by planes or cylindrical surfaces 9.

The form of the circle may be on top view (Fig. 1.3.1, c): Ball 11, cone 12 and cylinder 13 of rotation, other surfaces of rotation 14.

The top view in the form of the correct hexagon is the correct hexagonal prism (Fig. 1.3.1, d), which limits the surface of nuts, bolts and other parts.

Having determined the form of individual parts of the surface of the subject, we must mentally imagine the image of them in the form of the left and the whole subject in general.

To build a third view, it is necessary to determine which drawing lines it is advisable to take for the basic sizes of the image size. Usually axial lines are used as such lines (projections of the symmetry of the subject and the projection of the base planes of the subject). We will analyze the construction of the appearance on the left in the example (Fig. 1.3.2): According to the above type and form, to build a view of the left of the depicted item.

Comparing both images, we establish that the surface of the subject includes surfaces: proper hexagonal 1 and quadrangular 2 prisms, two cylinders 3 and 4 rotation and truncated rotation cone 5. The subject has a frontal plane of symmetry F, which is convenient to accept the size of the size of the size of the size of the sizes in the width of individual parts of the object when constructing its view on the left. The heights of individual areas of the subject are counted from the lower base of the subject and are controlled by horizontal communication lines.

The form of many objects is complicated by various cuts, cutouts, intersection of the surface components. Then it is previously necessary to determine the form of the intersection lines, and they need to build them at individual points, introducing the designations of the projections of points, which, after making constructions, can be removed from the drawing.

In fig. 1.3.3 The view of the left of the object is constructed, the surface of which is formed by the surface of the vertical cylinder of rotation, with a T-shaped neck in its upper part and a cylindrical hole with a front-precipitating surface. As basic planes, the plane of the lower base and the frontal plane of the symmetry F. The image of the M-shaped cutout on the side of the left was constructed using the outline of the cutout circuit A B, C, D, and E, and the line intersection of cylindrical surfaces - with the help of points K, L, M and they are symmetrical. When constructing a third type, the symmetry of the subject relative to the plane F.

An image of an object mentally dissected by one or several planes is called a cut. A mental dissection of the subject only applies to this section and does not entail changes in other images of the same subject. On the section show what is obtained in the secant plane and what is located behind it.

Cuts are used for the image of the inner surfaces of the subject to avoid large number Strip lines that can overlap each other with a complex internal structure of the subject and make it difficult to read the drawing.

To make a cut, you need: in right place subject to mentally carry out the securing plane (Fig. 1.4.1, a); A part of the object located between the observer and the securing plane is mentally discarded (Fig. 1.4.1, b), the remaining part of the subject is based on the corresponding plane of projections, the image is made or on the place of the corresponding view, or on the free field of the drawing (Fig. 1.4.1 , in); flat shape lying in the secant plane shackle; If necessary, give a cut designation.

Depending on the number of sequential planes, the cuts are divided into simple - with one sectional plane, complex - with several sequential planes.

Depending on the position of the securing plane relative to the horizontal plane of projections, cuts are divided into:
horizontal - the securing plane parallel to the horizontal plane of projections;
Vertical - securing plane perpendicular to the horizontal plane of projections;
Inclined - the securing plane is with a horizontal plane of projections an angle, different from the direct.

The vertical section is called the front, if the secant plane is parallel to the frontal plane of projections, and the profile, if the sequential plane is parallel to the profile plane of projections.

Complex cuts are stepped, if the sequential planes are parallel between themselves, and broken, if the sequential planes intersect together.

Sections are called longitudinal if the sequential planes are directed along the length or height of the object, or transverse if the sequential planes are directed perpendicular to the length or height of the subject.

Local cuts serve to identify inner structure subject in a separate limited place. The local incision is highlighted on the form of a solid wavy thin line.

The rules provide for the designation of cuts.

The position of the secular plane indicates the open cross section. The initial and finite triggers of the section line should not cross the circuit of the corresponding image. On the initial and finite strokes you need to put the arrows indicating the direction of the view (Fig. 1.4.2). Arrows should be applied at a distance of 2 ... 3 mm from the external end of the stroke. For complex The strokes of the open cross section line are also carried out in the cross-section links.

Near the arrows indicating the direction of view with outside The angle formed by the arrow and the cross section of the section, the capital letters of the Russian alphabet are applied on the horizontal line (Fig. 1.4.2). Letter notation is assigned in alphabetical order without repetitions and without skips, with the exception of letters and, o, x, b, s, b.

The incision itself should be marked with an inscription of the type "A - A" (always two letters, through a dash).

If the sequential plane coincides with the plane of the subject symmetry, and the incision is made on the place of the corresponding view in the projection link and is not divided by any other image, then for horizontal, vertical and profile cuts, it is not necessary to accompany the position of the securing plane and the incision is not accompanied by an inscription. In fig. 1.4.1 Front section is not designated.

Simple inclined cuts and complex cuts are always indicated.

Consider the characteristic examples of constructing and designating cuts in the drawings.

In fig. 1.4.3 A horizontal section "A - A" is performed on the site of the top view. Flat figure lying in the securing plane - the section of the section - shaded, and visible surfaces,

located under the secant plane, are limited to contour lines and are not shaded.

In fig. 1.4.4 Profile incision at the site of the view to the left in the projection connection with the main type. The securing plane is the profile plane of the symmetry of the subject, so the cut is not denoted.

In fig. 1.4.5 A vertical section "A - A", obtained by a securing plane, not parallel to neither frontal nor profile planes of projections. Such cuts can be constructed in accordance with the direction specified by the arrows (Fig. 1.4.5), or to have a convenient place of drawing, as well as with a turn to a position corresponding to the item adopted for this item on the main image. In this case, the sign O. is added to the designation of the section.

The inclined section is made in Fig. 1.4.6.

It can be drawn in the projection connection in accordance with the direction indicated by the arrows (Fig. 1.4.6, a), or have a drawing anywhere (Fig. 1.4.6, b).

In the same figure, a local section is performed on the main form, showing through cylindrical holes based on the part.

In fig. 1.4.7 At the site of the main species, a complex front-hand cut, made by three frontal parallel planes, is drawn. When performing a stepped section, all parallel secant planes are mentally combined into one, i.e. the complex incision is drawn up as simple. On the complex section, the transition from one sectional plane to the other is not reflected.

When constructing broken cuts (Fig. 1.4.8), one secular plane is parallel to any basic plane of projections, and the second securing plane is rotated to combination with the first.

Together with the securing plane, the cross section is turned into and the cut in it is performed in the cross section of the cross section.

The connection of a part of the form with a part of the cut in one image of the subject according to GOST 2.305-68 is allowed. At the same time, the boundary between the type and incision serves as a solid wavy line or thin line with a break (Fig. 1.4.9).

If half of the species and half of the cut are connected, each of which is a symmetrical figure, the symmetry axis of symmetry is served. In fig. 1.4.10 Four parts of the part are made, and on each of them half of the species is connected to a half of the corresponding cut. In the main form and the form on the left, the incision is placed on the right of the vertical axis of symmetry, and on the types above and below - to the right from the vertical or bottom from the horizontal axis of symmetry.

If the contour line of the object coincides with the axis of symmetry (Fig. 1.4.11), the boundary between the type and incision indicates the wavy line, which is carried out so as to save the image of the rib.

The shading of the cross section of the section included in the incision must be performed according to GOST 2.306-68. Colored, ferrous metals and their alloys are denoted in cross section with solid thin lines with a thickness of S / 3 to S / 2, which are carried out in parallel with each other at an angle of 45 ° to the lines of the drawing frame lines (Fig. 1.4.12, a). The hatch lines can be applied with a slope to the left or right, but in the same side on all images of the same detail. If the hatch lines are conducted at an angle of 45 ° to the drawing frame lines, then the hatch lines can be placed at an angle of 30 ° or 60 ° (Fig. 1.4.12, b). The distance between the parallel lines of hatching is selected from 1 to 10 mm depending on the hatching area and the need to diversify the hatching.

Non-metallic materials (plastics, rubber, etc.) are denoted by hatching intersecting mutually perpendicular lines (hatching "into a cell"), inclined at an angle of 45 ° to the lines of the frame (Fig. 1.4.12, B).

Consider an example. After performing a front-cut section, half of the profile cut with a half view of the left of the item specified in Fig. 1.4.13, a.

Analyzing this image of the subject, we conclude that the item is a cylinder with two through prismatic horizontal and two vertical internal holes,

of which one has the surface of the correct hexagonal prism, and the second is a cylindrical surface. The lower prismicito hole crosses the surface of the outer and inner cylinder, and the upper quadrogenic cylinder intersects the outer surface of the cylinder and interior surface Hexagon Prismatic Hole.

The front-line cut of the object (Fig. 1.4.13, b) is performed by the frontal plane of the symmetry of the object and is drawn at the site of the main species, and the profile section is a profile plane of the symmetry of the object, so neither one nor another is not necessary. The view of the left and the profile incision are symmetric figures, their half could be distinguished by the axis of symmetry, if it were not for the image of the rib of the hex hole that coincides with the axial line. Therefore, we separate part of the form to the left of the profile cut by the wavy line, representing most of the cut.

The image of the figure obtained with the mental dissection by one or several planes, provided that the drawing is only what falls into the secular plane is called a cross section. The section differs from the cut in the fact that it represents only what directly falls into the secular plane (Fig. 1.5.1, a). The cross section, like the incision, is the conditional image, since the section of the section separately does not exist from the subject: it is mentally separated and depicted on a free field of drawing. Sections are part of the cut and exist as independent images.

Sections that are not part of the cut are divided into rendered (Fig. 1.5.1, b) and superimposed (Fig. 1.5.2, a). Preference should be given to the sections of the submitted, which can be placed in the context between the parts of the same image (Fig. 1.5.2, b).

In the form of section, they are divided into symmetric (Fig. 1.5.2, a, b) and asymmetrical (Fig. 1.5.1, b).

The contour of the subsection is drawn up with solid main lines, and imposed - with solid thin, and the contour of the main image at the location of the superimposed section is not interrupted.

The designation of sections in the general case is similar to the designation of cuts, i.e. the position of the secular plane displays the cross-section lines, on which the arrows are applied, giving the direction of the view and denoted by the same uppercase letters of the Russian alphabet. Above the section "A - A" in this case (see Fig. 1.5.2, b).

For asymmetric superimposed sections or completed in the main image, the cross section of the arrow is carried out, but the letters are not denoted (Fig. 1.5.3, a, b). The imposed symmetric section (see Fig. 1.5.2, a), a symmetrical section made in the rupture of the main image (see Fig. 1.5.2, b), an extended symmetric section, made along the sequential plane (see Fig. 1.5 .1, a), are issued without applying a cross section.

If the sequential plane passes through the axis of the surface of the rotation that limits the hole or recess, the contour of the hole or the recess is drawn completely (Fig. 1.5.4, a).

If the sequential plane passes through a through a non-circular hole and the cross section is obtained by consisting of separate independent parts, cuts should be applied (Fig. 1.5.4, b).

Inclined cross sections are obtained from the intersection of the subject by the inclined plane, which makes up an angle different from the horizontal plane of projections. In the drawing, the inclined sections are performed according to the type of sections. The inclined cross section of the subject should be constructed as a set of inclined sections of the components of its geometric bodies. The construction of inclined sections is based on the use of a method for replacing projection planes.

When drawing out the inclined section, it is necessary to determine which surfaces that limit the object dissect the secular plane, and which lines are obtained from the intersection of these surfaces by this sectional plane. In fig. 1.5.5 Built the inclined section "A - A". The sequential plane crosses the base of the item along the trapezoid, internal and outer cylindrical surfaces - by ellipses whose centers lie on the main vertical axis of the subject. Reading the shape of the inclined section is simplified if constructing a horizontal projection of the inclined section as an imposed cross section.

When performing the drawings in some cases, it is necessary to build an additional selected image of any part of the subject that requires explanation with respect to the form, sizes or other data. This image is called a remote element. It is usually enlarged. The remote element can be posted as a view or as a cut.

When constructing a remote element, the corresponding site of the main image is noted by a closed solid thin line, usually by oval or circle, and denote the capital letter of the Russian alphabet on the shelf of the lifting line. The remote element is recorded by type A (5: 1). In fig. 1.6.1 shows an example of a remote element. It is possible is possible closer to the appropriate place on the image of the subject.

When performing various images of the Item 2.305-68, it recommends that some conventions and simplifications, which, while maintaining clarity and visibility, reduce the scope of graphic work.

If the view, incision or section are symmetrical figures, you can draw only half an image or a little more than half of the image, limiting it with a wavy line (Fig. 1.7.1).

It is allowed to simplify depicting the cut line and the transition line; Instead of lectal curves, there are arcs of circles and straight lines (Fig. 1.7.2, a), and the smooth transition from one surface to the other to be shown conditionally (Fig. 1.7.2, b) or not to show at all (Fig. 1.7.2, in ).

An insignificant taper is allowed or a slope to image enlarged. On those images where bias or taper is clearly not detected, only one line is carried out, corresponding to a smaller size of an element with a slope (Fig. 1.7.3, a) or a smaller base of the cone (Fig. 1.7.3, b).

When performing cuts show non-empty hand shafts, handles, screws, swords, rivets. The balls are always depicted non-Russian.

Elements such as knitting, thin walls, rigid ribs, are shown in the cut uncontrollable, if the secant plane is directed along the axis or the long side of such an element (Fig. 1.7.4). If there is a hole or deepening in such elements, then the local incision is made (Fig. 1.7.5, a).

The holes located on the round flange and not falling into the secular plane are shown in the context as if they are located in the securing plane (Fig. 1.7.5, b).

To reduce the number of images, a part of the subject is allowed between the observer and the securing plane, depicting a barchpunctive thickened line (Fig. 1.7.6). In more detail, the rules for image objects are set out in GOST 2.305-68.

To build a visual image of the subject we use axonometric projections. You can perform it by its complex drawing. Taking advantage of rice 1.3.3, Build Standard rectangular isometric Item depicted on it. We use the presented distortion coefficients. We will take the location of the start of coordinates (point O) - in the center of the lower base of the subject (Fig. 1.8.1). Having drawn the isometry axis and setting the image scale (MA 1.22: 1), we note the centers of the circles of the upper and lower bases of the cylinder, as well as circles that limit the T-shaped cutout. Draw the ellipses that are isometric circles. Then we carry out lines parallel to the coordinate axes, which limit the cutout in the cylinder. Isometric cross-cutting line cylindrical opening,

the axis of which is parallel to the OS axis with the surface of the main cylinder, we build on separate points using the same points (K, L, M and them symmetrical) as when building a view of the left. Then we remove the auxiliary lines and complete the finally the image taking into account the visibility of individual parts of the subject.

To build an axonometric image of the subject, taking into account the cut, we use the conditions of the problem, which is reflected in Fig. 1.4.13, a. On a given drawing to build a visual image, we note the position of the projections of the coordinate axes and on the OZ soybeans, we note the centers 1.2, ..., 7 of the objects located in horizontal planes G1 ", T" 2, ..., g7 ", is the top and lower bases of the subject, base of the inner holes. To transmit the internal forms of the subject, make cutout1/4 of the subject coordinate planes Xoz and Yoz.

Flat figuresThe resulting at the same time is already built on a complex drawing, as they are half the frontal and profile cut of objects (Fig. 1.4.13, b).

The construction of a visual image is starting with the axes of dimymia and the scale of the scale Ma 1.06: 1. On the z axis, we note the position of the centers 1, 2, ..., 7 (Fig. 1.8.2, a); Take the distances between them with the main type of item. Through the marked points we carry out the axis of dimming. Then we run in dimymium shapes first in the XOZ plane, and then in the Yoz plane. The dimensions of the coordinate segments take a complex drawing (Fig. 1.4.13); At the same time, the sizes along the axis y reducing twice. We perform hatching sections. The angle of inclination of hatching lines in axonometry is determined by the diagonals of the parallelograms built on the axonometric axes, taking into account the distortion coefficients. In fig. 1.8.3, and an example of choosing the direction of hatching in isometric, and in Fig. 1.8.3, B - in dimethics. Next, we build ellipses - dimethry of circles located in horizontal planes (see Fig. 1.8.2, b). We carry out the contour lines of the outer cylinder, the inner vertical holes, we build the base of these holes (Fig. 1.8.2, B); Drawing visible lines Crossing horizontal holes with outer and inner surfaces.

Then remove the auxiliary line of construction, check the correctness of the performance of the drawing and supply the drawing with the lines of the required thickness (Fig. 1.8.2, d).