Modern tendencies In the integration of combined processing led to the fact that grinding can also be carried out on the lathes. When issuing a quality problem to the fore, you always pay attention to the process finish treatmentwhich is called grinding - performing mechanical impacts for several passes to reduce the initial errors. Conduct a finishing processing with a turning cutter with quality, as when using grinding heads, it is impossible due to rounding the cutting edge. Also do not forget that turning machine With minor feeds, vibration may occur, which will lead to errors. For this reason, even if new materials appear, which can withstand a strong impact over a long time and not change their shape, grinding remains the main method used to obtain the surface of a high class of roughness.

Grinding Heads

Receipt of rotation bodies on turning machines is carried out over the past few decades. As a rule, grinding was carried out on other equipment. This moment determined the following technological process:

1. performing rough lathes for removing a large metal layer;
2. performing finishing turning for the preparation of the detail to the finishing stage of the technological process;
3. finishing on the circular chlorinated machine.

Such technological process determines the increase in costs due to the installation of a special machine to perform finishing processing. When creating a large batch of products acquisition grinding machine It pays off, but during small-scale production, its purchase will lead to an increase in the cost of one product. The exit from the situation can be called the use of special grinding heads, which can also be used to obtain a surface with a high roughness class.

Design features

Grinding heads are a special design that is used to significantly expand the capabilities of the lathe of the turning group. This mechanism is conditionally related to the snap. TO constructive features You can attribute:

1. the presence of its own electric motor, the power of which can be from 1 kW and more. This moment determines the fact that the head can be equipped for various models of turning machines. Typically, turning equipment has a closed gearbox and has no separate drive to connect the equipment under consideration;
2. the installed motor is connected to the circuit of the turning machine, which determines the versatility of the entire structure. It also has a three-phase plug for inclusion in a separate supply circuit;
3. the head has its own bar, which, when modernizing, can be fastened hard instead of a standard cut holder. This moment determines that the equipment allows you to get high-quality surfaces at high process mechanization. In the manufacture of the bed, steel is used, which allows preventing vibration when working by increasing the stiffness of the structure;
4. rotation transmission passes with belt transmission to lower revolutions.

The design is pretty simple. When it is considered it is worth paying attention to the type of bed. This is due to the fact that only a certain type of bed may come up instead of a cut holder to a certain model of the lathe.

Grinding head HRP 150

There are several popular models of heads for round grinding, among which we note HGP 150. It has the following features:

1. comes with a spindle for external grinding with a circle diameter of 125 millimeters;
2. the VGP 150 version can also be used to grind internal surfaces with a circular diameter of 8 to 40 millimeters;
3. models of the model can be carried out on a turning group with a stiletto diameter for a sharp holder not more than 22.5 millimeters. At the same time, the VGP 150 window has an adjustment surface of 202 by 102 millimeters;
4. with external grinding, the frequency rate of the spindle speed at idle is 5000 rpm, for internal - 16,800 rpm at idle. During operation, the indicator can significantly decrease, which depends on the value of the transverse feed. With a strong feed, there is a probability of a belt slipping on the installed pulleys, which makes it possible to exclude the probability of displacement of the output shaft of the electric motor relative to the windings, as well as its deformation;
5. vGP 150 drive shafts are installed on precision bearings;
6. spindle sleeve and motor base has the ability to adjust that more than increases the versatility of the device;
7. with the help of belt transmission, it is possible to adjust the speed of rotation of the circle, depending on the tasks assigned, as a rule, there are 2 transmissions;
8. using HGP 150 can be used to obtain dimensions with an accuracy of 0.01 to 0.02 millimeters. This moment determines that the model 150 and 200 can be used to obtain a high purity surface.

The maximum diametrical size of the workpiece when using HGP 150 is limited to the longitudinal movement of the caliper and depends on the characteristics of the lathe.

Steel and cast iron with the help of the equipment under consideration can pass the finishing process on the lathe. At the same time, it is possible to achieve the same rashness indicator as when using round-fluffy equipment. Model 200 differs from the power under consideration of the installed electric motor and the maximum diametrical dimensions of the mounted circles. Similarly, it is possible to lower the cost of producing parts by increasing the universality of the equipment used. In this case, we note that the equipment is suitable for old and new turning equipment, as it has universal use.

Finishing operations are performed to increase the purity, the accuracy of processing or creating on the surface of the part specifically provided by the roughness of a specific pattern. To this end, the lathes produce lying, polishing, finishing, thin sharpening, running, rolling, smoothing and rolling.

§ 1. Filing

Purpose. Quality is made for stripping surfaces, removal of burrs, removal of small beams, and also for cutting a slight layer of metal when the diameter after the calculation turned out to be more required.
Instruments. Fuling is performed by files of various shapes: flat, square, triangular, round, etc. for rough work Apply the drakeer files, for clean - personal and, if necessary, obtaining high purity surfaces - velvet. They differ among themselves with a number of notes on an equal length.
Before using the files should be inspected and, if necessary, clean from dirt and chips with a metal brush by moving it along the notes. The grilled files are pre-rubbed with a piece of dry chalk or charcoal.
Work techniques. To prevent injury, filling on the lathe should be guided carefully and carefully. You can use only files with a tightly planted handle. During fluctuation, the turner should stand approximately at an angle of 45 to the right to the axis of the machine centers. The handle of the file is clamped in the left hand, and the opposite end is held with the fingers of the right hand (Fig. 198),

B The process of filling the file is perpendicular to the axis of the part, slightly pressed to the treated surface and are smoothly moved simultaneously forward and to the side. When moving back, push slightly weaken. Fast and sharp movement of a file breaks out the part form. Push on a file should be the same throughout


Its turn, otherwise the removal of metal will be uneven, which will lead to the distortion of the form of the treated surface.
Mode of operation. The circumferential velocity of the treated surface when describing is taken equal to 15-20 m / min.

§ 2. Polishing

Purpose. Polishing is performed to increase the purity and gloss of surfaces, as well as the preparation of them under electrolytic coating chrome or nickel.
Instruments. On lathes, polishing is carried out by grinding skins on paper or canvas. Steel and colored plastic metals are treated with corundum skins, cast iron and fragile materials - silicon carbide skins. The grain of the skin (the size of the abrasive grains in the hundredths of the millimeter) is made depending on the required purity of the treated surface in the range of 50-3;
Work techniques. A piece of skirts hold with the fingers of the right hand or both hands for its ends (Fig. 199, a),


Made to rotating, parts and moved reciprocating along the polished surface. Hold the skin with hand in the girth is impossible, as it can get wound on the part and pinch your fingers.
When polishing, the machine stands the same as when describing, approximately at an angle of 45 ° to the right to the axis of the machine centers. The front end of the skins hold the left hand opposite - right.
Polishing is performed sequentially several skins with a gradual decrease in their grain.
Cylindrical surfaces are conveniently polished by lines (Fig. 199, b). They consist of two wooden bars connected on one end of the skin or metal hinge. In the internal radius deepening of the bars, the grinding skin is stacked. The treated surface is covered with a fat that is held with their hands, and polishing the actions :: similar to those described above.
When polishing, the part is very hot and lengthened. Therefore, when it is pressed by the center, it is necessary to periodically check how tight it is clamped, and, if required, weaken a little.
Mode of operation. For better cleanliness of the surface, the number of revolutions of the part should be large. With the final polishing, the surface surface is recommended to slightly lubricate the oil or rub the skin with chalk.

§ 3. Thin sharp

Purpose and essence. The outer and internal surfaces are treated with thin sharpening with an accuracy of 1-2 classes and 8-10 classes. This type of processing in many cases can replace grinding.;
Its essence consists in cutting a small metal layer with a very low feed and high cutting speed.
Requirements for machines for fine sharpening. Machines should be rigid, accurate (radial spindle bias not more than 0.005 mm), speed (the number of revolutions of at least 2000 rpm) and have a feed of less than 0.1 mm / r. Limbs or indicator stops should allow the installation of cutters per size with an accuracy of at least 0.01 mm.
Without resorting to special devices, the accuracy of feeding the cutter to the cutting depth on any turning machine can be increased by using the top-sled leb, turned to some angle and the axis of the machine centers (Fig. 200). If we take T - the magnitude of the movement of the cutter in the angular direction, A T \\ is perpendicular to the part axis, the desired angle of the sprawler of the Salazoka can be determined from the formula


Example. For the price of dividing the limb of the upper sled sled 0.05 mm, it is necessary to increase the accuracy of moving the cutter to the depth of cutting to 0.01 mm. Determine the angle of rotation of the upper sled.
Decision. In this case, / i \u003d 0.01 mm, t \u003d 0.05 mm,
By formula (27)


Applied cutters. Cutters for thin sharpening are equipped with solid alloy plates VK2 brands or VKSM for processing cast iron and T30K4 for steels. For non-ferrous metals and plastics apply diamond cutters.
After sharpening the cutters are necessarily brought. Main cutting edge


It must be acute, without chamfer. Divues or minor jar on it are not allowed.
The peak is twisted with a radius of 0.5-1 mm:
The front angle y for carbide cutters during steel processing from -5 ° to + 5 °, for cast iron - 0 °. For diamond cutters when scrapping y \u003d - 4 °, during reassurance y \u003d 0 °. The rear angle is performed within 6-12 °.
Introduction and cutting modes I am. Package for fine precision is left in the range of 0.25-0.4 mm per diameter with a detail diameter up to 125 mm.
Cutting modes are usually limited to the capabilities of the machine. They are recommended to choose within the following limits: cutting depth of 0.05-0.2 mm; feed under pre-treatment 0.1-0.2 mm / o, with the final - 0.02-0.08 mm / O; cutting speed for ferrous metals 100-200 m / min, for non-ferrous - 200-500 m / min.

§ 4. Revodka

Purpose and essence. Closings of surfaces are performed to increase their accuracy to 1-2 classes and purity of over 9th grade.
In the process of adjustment using special tools, saturated with abrasive powders or pastes, the smallest irregularities are removed from the surface of the part, as a result of which it acquires the necessary accuracy and purity.
Abrasive and binding materials. The working surface of the prit is saturated with abrasive powders or pasta. To do this, apply the solid abrasive materials: electrocorundum powders for finishing steels and silicon carbide - for cast iron and other fragile materials.
The grain of powders is selected depending on the required purity of processing. Rough crib with the purity of V9-V1O is performed by grindpores grain 5-3, preliminary with purity to V 12 - M40- M14 micropowers; Clear with purity to V 14 - M10 - M5 micropowers (for micropowers, the grain number corresponds to the grain sizes in microns).
From the convective paste the greatest spread of gay pastes. They contain soft abrasive material - chromium oxide (70-85%), as well as active chemical and binders. They enjoy for finishing steels and non-ferrous metals.
According to the conversion ability, the Goe paste is divided into coarse, medium and thin.
Kerosene or mineral oils are used as binders and lubricating materials.
Pritry. They are bushings with a longitudinal section that allows them to adjust them in diameter to compensate for wear. For the holes of small diameter, unregulated feeders are used: as a round rod.
The final finishing is carried out with a smooth surface (Fig. 201, a). Fees for pre-finishing (Fig. 201, B and B) are equipped with longitudinal or screw grooves in which they are going to


Remains of abrasive material during operation.
Fees 3 for the treatment of holes have conical hole With a taper 1:50 or less than 1:30. They are installed on a mandrel 1 with the same taper (Fig. 201, d) and can be adjusted by diameter due to the axial movement of nuts 2 and 4. The tritters 3 (Fig. 201, e) for finishing shafts are installed in the fates 1 and adjustable with screw 2 .
The feed material is chosen depending on its purpose and. used abrasive material.
When finishing with solid abrasive materials, the grains of which are pressed into the test, the material of the latter must be softer material of the workpiece. In addition, the larger the grain of the powder used, it is necessary to choose a softer material for the feed.
For coarse finishes, feeders made of soft steel, copper, bronze, brass, and for pre-and finishing - from fine-grained gray cast iron of medium hardness (HB 140-170).
For work with soft abrasive materials (pastes based on chromium oxide, iron oxide., Goe pastes), whose grains are not quenched, the tie must have a greater hardness than the trigger item. In this case nice results Provided by the use of treads from hardened steel or gray iron cast iron (HB 200-220).
Fees are made with high accuracy. Their error geometric shape should not exceed 0.005-0.01 mm.
To prevent jamming in the process, the trigger diameters must provide some clearance in connection with the part. The following gaps are recommended: for coarse finishes - 0.1-0.15 mm, for pre-0.03-0.06 mm, for finishing - 0.005-0.01 mm.
Preparation of the feed to work. Saturation (cartoon) The surface of the feeding of solid abrasive materials is performed by a direct or indirect way.
For live method Specifying the surface of the feed is slightly wetted by kerosene or oil and is evenly sprinkled with a thin layer of abrasive powder. The abrasive grains are then pressed into the test by rolling it along the steel hardened plate or rolling with a tempered roller.
An indirect way to cartoon is simpler, but less effective. In this case, the abrasive powder sprinkled on the lubricated surface of the feed, which is scheduled during the refinement.
The goe paste is thickly divorced by kerosene and uniform thin layer applied to the surface of the prit.
Preparation of details under the finish. The surface of the part must be processed under the finishing, fine, fine-sharpening or grinding. The smaller point will be left under the finishes, the more accurate and quickly can withstand the desired size and purity of processing. Under the finishes, it is recommended to leave the allowance of 0.01-0.03 to the diameter.
Receivers. When entering outdoor cylindrical surfaces, the processed part is fixed in the cartridge or in the centers, and the tread is put on it and evenly slowly move manually along the rotating part. With wear, the prit is adjusted by diameter.
For pumping holes, the ties is fixed in the spindle or cartridge, and the part on it is kept with hands and move evenly in the longitudinal direction.
Additionally, saturate the test can only be abrasive powder or pasta of the same graininess or larger. Preliminary and final finishes are performed by different pritses.
Revision mode. The circumferential velocity of the part or the feeder is taken with a pre-finishing of 10-20 m / min, with the purpose of reducing the heating and expansion of the part, the speed reduces to 5-6 m / min

§ 5. Stringing surface treatment with rolling, rolling and smoothing

Purpose. These types of processing provide for the purpose of hardening the surface layer of the part, increase its wear resistance and improving surface purity to 8-10 classes. The process takes place without removing the chips by smoothing the roughness obtained after the sharpening.
Instruments. Outdoor surface rolling and rolling holes are performed by roller and ball rolling and rollers, smoothing is done with diamond tips.
Officer with a symmetric arrangement of the roller on two supports (Fig. 202, a) is used to treat outdoor cylindrical and conical surfaces on the passage. The roller has a spherical profile (Fig. 203, a). If necessary, processing stepped surfaces, ledges and. The ends are used with a single-sided roller run (Fig. 202, b), the forms of the working profile of which are shown in Fig. 203, B, B and G. for running

The rollers and ends of the roller are at an angle of 5-15 ° to the surface being processed.
Rollers are made of alloyed steel x12m or 9xc and hardened to HRC 58-65 hardness.
Ball rugs and rolling (Fig. 202, in, g, d) are equipped with a spring, which ensures uniform ball pressure on the part. The required spring pressure, depending on the properties of the material being processed, is set by the adjusting screw. Such run-in and rolling allow you to successfully process non-rigid parts, as the ball, having a point contact with the surface, does not need a strong subference. Officers (Fig. 202, c) are convenient for processing ends and ledges.
For running time, rolling bearings are used.
Diamond tips 1 (Fig. 204) are designed to smooth the surface of the part. They are a diamond holder working surface which has a spherical or cylindrical shape. Tips are fixed in a cylindrical mandrel 2 and together with it are installed in the housing 3. The required pressure of the diamond on the treated surface is created by an adjustable spring placed inside the housing.
Preparation of the surface of the part. Under the hardening processing, the surface of the part is prepared by the first sharpening. The degree of roughness should be within 5-6 classes of purity. In this case, it is necessary to take into account that the diameter of the surface during the hardening processing process may vary up to 0.02-0.03 mm. Therefore, the outer surfaces of the part should be performed by the largest limit

Size, and the internal one by the smallest.
Work techniques. The strengthening tool, fixed in the cutting machine, is supplied close to the surface of the rotating part. It is not a strong, but sufficiently dense regulation and for 2-3 reciprocating passages with a mechanical feed processing to achieve the desired purity of the surface. To reduce friction and heating parts, the treated surface is recommended to lubricate with oil.
Processing mode. Feed: When running with a ball - no more than 0.1 mm / O, roller with a radius profile - 0.1-0.2 mm / about. Alphanumerate diamond is performed with a supply of 0.03-0.06 mm / about.
The speed of rotation of the product is 40-80 m / min.

§ 6. Rolling

Purpose. Rolling is created on the surfaces of some details (knobs, screws, etc.) specially provided roughness in the form of rifes of a particular pattern.
Tools and install them on the machine. Rolling is performed by opposites, consisting of a rolling roller and the holder (Fig. 205), for applying a direct pattern (Fig. 205, a) use single-rolled knotting, mesh (Fig. 205, b) - two-solid, respectively with the right and left directions of rifrances.
Rolling rollers 1 are made of Tool steels of U1-2A or HGH and hardened until HRC 63-65 hardness. On the cylindrical surface of the rollers with milling, rifles are performed with an angle of a profile of 70 ° for rolling steel parts and 90 ° - for parts of non-ferrous metals. Depending on the diameter of the processed partable parts, the circumference is placed in increments from 0.5 to 1.6 mm.
The pump is fixed with the smallest departure in the caliper of the caliper so that the forming the roller, there is strictly parallel to the axis of the part. The check is performed on the surface being processed on the lumen. The axis of the single-ring roller must be at the level of the axis of the machine centers. For two-role comction, the accuracy of the installation in height: does not matter, since in this case the rollers are self-controlled along the surface being processed due to the hinge compound of the rope 2 with the holder 3 (see Fig. 205, b),
Preparation of the surface of the part for rolling. When rolling, the metal is extruded. Therefore, the surface of the parts is calculated to rolling to a diameter, less than a 0.25-0.5 rifle steps.
Rolling receptions. The rollers are injected close to the rotating part and the manual transverse feed are pressed into the treated surface to some depth. Turning off the rotation of the part, check the accuracy of the resulting pattern. Then includes the rotation of the spindle and the longitudinal supply and perform rolling to the desired length for several passes in both sides until the full height of the rifes is obtained.
It is impossible to remove the rollers from the treated surface during the entire process of rolling, as they may not get into previous ripples and the pump drawing will distort.
Rolling rollers should be periodically cleaned with a wire brush from stuck in metal particles in the recesses.
Rolling mode. The longitudinal supply is taken approximately equal to the doubled value of the rifle steps (1-2.5 mm / O), the speed of rotation of the part - in the range of 15-20 m / min. The treated surface is lubricated with oil.

Turning machines are used to process the parts of the cylindrical form. They include many varieties that differ in size and presence additional features. Such industrial models are very common and widely used in the modern industry. To function normally function, you need to know all the features of its details.

The strinner of the lathe is used to secure almost all the mechanisms and nodes that are used on this equipment. Often it is cast from cast iron to get a massive and sturdy constructionThat was able to serve long term. This is due to the fact that it will be exposed to large loads. You should not also forget about stability, since massive large models use huge energy during operation and the base should be good to resist the loads.

The bed and the guide machines are attached with the help of bolts to the cabins or paired legs. If the device is short, then two racks are used. The longer it is, the more racks may be required. Most Tumb has doors, which allows them to be used as drawers. The guides should be very careful and to protect their ability to damage. It is not desirable to leave tools, blanks and other products on them. If you still have to have it metal subjects, Before you should put a wooden lining. For better care, Before each use of the machine, the face must be wiped and lubricated. When the work is completed, it should be removed from it chips, dirt and other extra objects.

The features of the design of the steel milling machines may differ depending on the specific model, as they are developed for convenient and safe placement of all equipment nodes. But the main provisions in many cases remain the same, so that on the example of popular models you can consider the basics.

pHOTO: Cast iron furniture

1. Longitudinal edge;
2. Longitudinal edge;
3. Cross edge, serving for longitudinal ribs;
4. Prismatic guides of longitudinal ribs;
5. Flat guides that serve to install the posterior and front grandmother, as well as to move the caliper on them;

It is worth noting that the guides of the beds cross section can have various forms. Mandatory rule is observing parallel location, so that everything should be equidistant from the axis of the centers. This requires accurate milling or planing. After that, there is an operation on grinding and shabry. All this ensures accurate processing of products, as well as the elimination of problems with the movement of the caliper and the occurrence of the impetus.

• The stanne of the lathe for metal, which is presented in the figure "A" under the numbers 1 and 2, has a trapezoidal cross-section of the guides. In this case, the main emphasis is made on a large support surface. They have great wear resistance, which allows for a long time to leave their accuracy. At the same time, to move the caliper on them you need to make a lot of effort, especially if it twisted.
• Figure "B" shows a bed with flat rectangular cross section guides. Unlike the previous one, they have already two ribs of rigidity, and not one, which makes them stronger.
• Figure "B" demonstrates the bed with the guides of the triangular section. With the fact that a sufficiently low support surface is used here, it is difficult to work with a lot of weight, so this species Used mainly for small machines.
• Figure "G" shows the face with a triangular cross section and a support plane. In this case, it is also used for small-dimensional machine tools.

If the bed is intended for a heavy machine, it has not only a large cross section, but also greater bending resistance. One of the most common is such a species, as presented in the Figure "G". Here the caliper carriage focuses on the prism No. 3 in front, and the back rests on the plane No. 6. In order not to roll over, it holds the plane number 7. If the direction is tasked, Prism №3 plays the main role, especially since it perceives most of the pressure performed by a cutter.

If there is a notch on the front side of the front grandmother, it serves for a class to handle products big diameter. If the product is processed, the radius of which is less than the height of the centers, then the recess is overlapped with a special bridge.

Repair of lathe bed

The string of the lathe bed is a technological process during which the window is evoked to secure the feed box with a frame level. Due to this, it will be possible to easily install the perpendicular to the surface of the caliper fastening and the apron to the feed box.

1. The first thing the bed is installed on a rigid foundation and check the longitudinal direction along the level along the surface, and the transverse direction on the frame level. Permissible deviations are no more than 0.02 mm per 1 meter length of the product.
2. Sharbed the upper surfaces of the guide, first on the one hand using the calibration line on the paint. During this process, it is advisable to periodically check the eruption of the guides.
3. Then the Surface of the second guide is then. The maximum deviation tolerance here remains the same 0.02 mm per 1 meter length of the product.

Grinding bed lathe

Grinding the lathe of the lathe consists of the following procedures:

1. It is necessary to spend stripping and roascing the scaling and calemen available on the surface;
2. The bed is installed on the table of a longitudinal-planing machine and securely fixed there;
3. Next is the verification of the eruption of the guides, which is carried out laid on the bridge of the backstone level;
4. During the installation of the bed, a small deflection of the product is obtained, which should be corrected by the maximum dense contact with the table;
5. Repeatedly checked the heading of the guides so that the results coincide with what was before consolidation;
6. Only after that, they begin grinding all the contact surfaces of the product. The procedure is carried out using the end of the circle of a cup form. Its graining should be K3 46 or KCh 46, and the hardness correspond to SM1K.

Polishing on a turning machine in order to obtain high cleanliness of the surface (V9-V11) is carried out by an abrasive skurt, which is a web with a layer of abrasive grains pasted on it. Depending on the size of the grains, coarse skins are distinguished (No. 6, 5, 4), Middle (No. 3, 2), small (No. 1.0) and finishing (No. 00,000).

Polishing on the lathe is performed with the help of lines - two hinged-bound wooden pads, between which the abrasive skirt is invested (Fig. 232). Tokar holds the femors for the handle with the left hand, creating the necessary clamp of the skins to the workpiece (parts), and right hand Supports hinge and exercises longitudinal flow. It is possible to fix the skin into the slitcertel with a wooden pad with a billet (parts) of the skin (Fig. 233, a), or with a clamp of the billet (Fig. 233,6). It is not allowed to fit the skins to the workpiece (part) manually.

When internal polishing, the skin is wound on a wooden mandrel, fixing the end of the skins in the slot of the mandrel. It is not allowed to polish the hole with the clamp of the skin with hand or finger m.

District speed when polishing with a skin is reached 60-70 m / min. In the polishing process, to protect the cartridge from entering it abrasive dustClose the hole in the chuck plug out of the foam. Guides of the beds are covered with a tarp cloth.

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The most widespread devices for turning and grinding work are centers, cam and collet cartridgeswhich also apply with other works (for example, drilling).

In fig. 122 shows the design of the lathe centers: normal (Fig. 122, α), with a spherical end (Fig. 122, b), used when displaced the axial line of the workpiece relative to the line of the machine centers, semicentrators (Fig. 122, B), allowing you to combine outdoor Longitudinal sharpening and trimming of the ends. To increase the wear resistance of the centers, they are reinforced by a solid alloy or metallizing the cone surface.

Due to heating in the process of cutting, causing the elongation of the processed workpiece, the clamping force varies. In order for the clamping force to be constant, compensators have a rear grandmother different designs: Spring, pneumatic and hydraulic, which allow you to slightly displaced the pinol when heating the workpiece. Such compensators are usually used when fixing the workpiece in rotating centers.

To prevent the deficit of non-fastened shaft blanks, as additional support Apply luntin Movable or still type. The usual designs of fixed universal linnets do not meet the requirements of high-speed processing, since the lyuba cams made from bronze or cast iron are quickly wear out and the clearance is formed in their interconnection, which leads to vibrations. V. K. Seminsky offered to modernize Lunet (Fig. 123).

At the base of 1 luna, instead of cams 7, ball bearings are installed, and the socket under the cam in the lid 2 is mounted and insert the rod 4 from the spring 5. The stem 6 is fixed with two ball bearings. Lune's base ball bearings are set to the diameter on the control roller installed in the centers, or by the most processed billet.

Then, the luna cover 2 and nut 3 adjust the position of the rod 4 with such a calculation to the gap between the base and the lid. was 3 ... 5 mm, After that, the eccentric 8 presses the lid. At the same time, the springs 5 \u200b\u200bare compressed and ball bearings installed in the earrings, with force begin to press the processed item to the base ball bearing.

Beying due to ovality and unequal thickness of various sections of the workpiece of the workpiece under this structure is perceived by the spring 5, which works as a shock absorber.

The most common torque transfer devices to the processed billets on the spindle of the front grandmother are leopal devices: Clamps, brackets, leashes, leashes, leashes, leashed cartridges, cam cartridges, collet clamping devices.

Conventional and self-consuming clamps have limited use, as they require considerable time to install, so self-argued leashed mandrels are used more often. Installing and removing the workpiece in this case, when rotating the spindle. The workpiece installed in the centers is moved to the left pinley, the back of the grandmother, while the teeth of the leash are pressed into the end of the workpiece, which ensures the transmission of torque from the spindle to the workpiece.

From cartridges used for installation and fixing blanks on turning machines, the most common self-centered three-tech cartridges. To secure asymmetric blanks, usually four-digit cartridges are used with independent movement of each cam with a screw.

When basing the processed workpiece by internal surface Apply expatriate mandrels with a pneumatic drive. The most characteristic design of the pneumatic leash cartridge is the cartridge shown in Fig, 124. In this design, you can install and remove the workpiece without stopping the machine spindle. The cartridge is equipped with an automatically locking floating center. In the holes of the device housing installed plungers 7, in the grooves of which are gear wheels 5, rotating on the plugs 7 axes 6. The gear wheels 5 are engaged in engagement with the wedges 8, which with their swelling with crushed liners 4 in the grooves of the pads 3 , move the pads with the eccentric cams of the clamping billet. Fist 1 rotate on axes 2 fixed in pads 3.In the middle of the cartridge there is a sleeve 14 with floating cartridge 16, rigidly connected with the cartridge housing. Head 10 is associated with a rod of a pneumatic cylinder rocking chair 9.

When the head 10 pushes the plunger 7 and feeds the sleeve 15, sitting on the sleeve 14. The fists 1 with spring plungers 11 are pressed to the resistant screws 12, which provide a touch of the middle part of the surface of the cam and clamping workpiece. When leaving the cams 1 in the processed billet, gear wheels 5, rolling on the teeth of the wing wheels 8, move the sleeve 15, which is pressed by its body and three balls 16. Pads 3 with cams 1 in non-working condition are held with spring plungers 13 at the same distance from the center of the cartridge .

In fig. 125 shows the design of the backstart of a lathe with a built-in rotating center and a pneumatic cylinder for moving pinole. This device allows you to reduce the time of time to move pinol. Pinol 2 moves with a rotating center 1 by means of rod 3 and piston 5 pneumatic cylinder 4. When compressed air Enters the right cavity of the cylinder, the piston, moving to the left, pushes the stem pin to the processed billet.

Pneumatic cylinder 4 is rigidly fixed on the housing of the backstone. Using the distribution crane 6, drive control.

For the processing of blanks on turning machines, pneumatic three-tag cartridges with adjustable cams are used. The use of adjustable cams is due to the need to process billets of various sizes. Frequent permutations of cams (or linings) cause them to drag or grind, which naturally makes it difficult to change, especially during the working day. Shown in fig. 126 The design allows not only to adjust the cams depending on the shape of the workpiece or its size, but also quickly overlap the cartridge to work in. centers. In the housing 2 of the cartridge there is a coupling 1, connected by carvings with a pneumatic drive.The sleeves include the long ends of three levers 3, and their short ends - in the grooves of the slider 4, connected by the screws 5 with fists 6. On the end surface of the cartridge, the ring risk 7 is applied, and on cams there are divisions that allow pre-installing cams. When fixing the cartridge for work in centers in the central hole insert transition sleeve With a normal center, and one of the cams are used as a leash.

In some cases, processed billets with colors or flanges are advisable to center on short hard fingers or in shades and clamp along the axis. In fig. 127 shows the design of a pneumatic device for the axial clamp of a thin-walled sleeve with a collar. The sleeve is centered in the disk inclusion attached to the housing 1, and clamping along the top of the three levers 6 placed on the axis 5. The levers are driven by a knife connected to screw 2, when moving with a rocker 4 along with the levers 6, clamping the workpiece . When the thrust is moving from left to right, the screw 2 by means of nut 3 moves towards the rocker 4 with levers 6. The fingers on which the levers 6 are planted are slide along the disk-plated discs 7 and thus, when the processed billet is fed, it is somewhat lifted (as shown by a thin line), allowing you to release the processed part and install a new workpiece.

Burtic fixture allows you to process both external and internal surfaces.

Pneumatic devices with interchangeable clamping levers are also used in enterprises, providing the concentricness of the outer and internal treated surfaces. The design of such a device is shown in Fig. 128 and is a housing 5, inside which levers 2 and 4 are installed on the hinge axes. The short ends of the levers protruding outwards, and the long mounted in the rectangular stem size 3. In the threaded hole of the rod, the thrust 1, connected to the rod of the pneumatic cylinder (not shown in the figure). The enclosure of the device is centered on the table cheeper 7 of the sleeve 6.

When traction moves 1 with a stem 3 on the right left short ends of the levers 2 and 4 clamping the workpiece.

Cartridges are also used with the installation of blanks over the processed bases. In fig. 129 shows the design of the cartridge with the installation of the workpiece along the central opening and the clip for the flange. When filling the cam 3, sitting at the ends of the rods 1, with their protrusions rest on the bar 2, unloading the rods from the bending strength. When the processed fist, 3 lower-outer protrusions 4 rest in the bar 2, freeing the part, and the internal protrusions 5 are confronted from the installation finger.

For processing on mandrels apply different kinds Scroll pneumatic devices. In fig. 130 shows the design of a three cam extension mandrel. It consists of a housing 2 with a cast-iron threaded sleeve 3, screwed onto the machine spindle. The workpiece is clamped with three cams 4, located at an angle of 120 ° in the holes of the mandrel housing and extended by three wedges with a sleeve. The sleeve moves the burden 1 from the pneumatic drive. Futs 4 are returned to its original position when the processed part of the spring rings is released 6.

The main disadvantage of the pneumatic drive at the rear end of the spindle is the impossibility of processing rods. In fig. 131 shows the design of a pneumatic collet cartridge, which allows you to process the blanks from the rod passing through the holes of the machine spindle. In this design, compressed air enters through the junction box, reinforced at the rear end of the machine spindle. Air duct OT distribution box The cartridge is located in two metal tubes 1, charged in the tube grooves 2.

When the harness of the blank, the compressed air is sent to the right cavity of the cartridge, moving the piston 3 with the ring one brought to it 5. This ring, pressing on the cams 6, moves them along the conical surface of the sleeve 4, thus clamping the billet. To link the processed part, compressed air is sent to the left cavity of the cartridge, shifting the piston 3 to the right, while the cam 6 under the influence of the spring ring 7 is diverted.