Preparation of belt saw reference manual. Machines for rollerizing wide band saws, frame and disk saws machine for rolling of narrow tape saws
11. Preparation of tape saws: rolling, sharpening teeth, repairing saw.
The rolling is an operation, as a result of which the saw in the canvas is pre-(before installation in the machine), useful internal stresses are created, increasing the transverse rigidity of the saw, created by tensioning it on the machine pullees. With a symmetric rolletin, three - five tracks are failed in width from the middle to the edges: the extreme tracks - at a distance of 10. ..15 mm from the line of the teeth, and from the rear (back) edge of the saw. The correctness of the rolling is controlled by transverse curvature (arrow of deflection on the width of the tape) with a special template. The arrow of the deflection normally failed saw is for cylindrical machine pulleys 0.15 ... 0.3, for barrel-shaped - 0.4 .. .0.6 mm (large values \u200b\u200bare more subtle and wide saws).
The sharpening of the teeth of the ribbon saws is made on the machines of the Corundic circles of the flat 45 °-needle conic profile (ZP) with graininess 40 .. .25 on the bakelite (b) bond with hardness C1 - ST1. The thickness of the circle is 0.2, .. 0.33 steps of teeth. Good quality provides the following sharpening mode: District circle rotation speed
20 .. .25 m / s; Cutting in one pass 0.02 .. .0.06 (up to 0.1) mm; The number of passes 4 .. .6 (up to 7).
Brothering of teeth is conclusable in the front of the front and rear edges with fine-grained donkey, fixed in a special holder. Resistance of saws with communicated teeth increases by 15..20%. Runs are performed using manual fixture.
Repair of shells of ribbon saws includes localization of cracks, cutting of defective zones of the canvas and preparation of sections of inserts. Localization is subject to single cracks with a length of no more than 10-15% of the saw width, but not more than 15 mm. Localization is carried out by setting the holes with a diameter of 2 ... 2.5 mm at the end of the crack.
With single long cracks, as well as group cracks (4-5 pcs. At a length of 400-500 mm) and broken in a row two teeth, a defective place is cut out. The length of the cutting should be at least 500 mm in order to avoid difficulties when editing.
12. Installation of tape saws: Tension methods, guide devices, adjustment of pulleys.
1. The cutting edge of the saw should appear over the edge of the saw pulley to the height of the tooth.
2. The displacement of the tape for pulleys is prevented by regulation of the position of the axis of the upper pulley (along with the pulley) in the vertical (tilt forward - back) and the horizontal (reversal to the left - right) planes. The angle of inclination of the pulley forward (on the working) is 0.2-0.3 °.
3. The force tension force, H, the total tape for both branches, is set depending on the width and thickness of the saw:
where σ is the tension voltage in the ribbon cross section (50-60 MPa); a., b. - width and thickness of the ribbon, mm.
4. The gap between guide devices and saw should be 0.1-0.15 mm. Contact saws with guide devices is allowed only when drinking curved parts.
5. When working, the tape saw should not have wave-like movements and produce vibrating sounds. The tension force must be minimal excluding these phenomena.
6. Do not allow long-term operation of the saw in good. With long-term stops, the tension from the saw should be removed.
7. It is necessary to regularly purify the saw blade from the resin, dirt, pumped sawdust.
8. In some cases, good results gives the use of lubricant saw with water, soap solution, a mixture of diesel fuel and machine oil with a drip method or spraying.
1. Requirements for tape saws.
The saws should be cleaned of anti-corrosion lubrication, dirt, depressing and carbon wood, formed during operation. Lubrication is removed using kerosene or solar oil, after which the saws are wiped with a rag. Woods are tailored to a metal scraper by moving it along the canvas, grinding her skin.
When preparing a ribbon sawing to operation, a number of technological and control operations must be performed, the list of which is shown in Table 1.
Preparation of new and applicants in the operation of tape saws differ in quantity, sequence and composition (volume) of operations. On the "Dzzz" in the preparation of new saws, almost all technological operations are performed in full. The composition of operations during repair saws depend on their actual state, which is determined at the current control after each period of operation.
Table 1
Tape preparation operations
Technological operations of preparation and control of tape saws
After the operating period
1. Control of the canvas for compliance with the technical requirements of GOST 6532-77, GOST
2. Connection of the ends of the canvas (welding)
3. Connection quality control
4. Quality control of the editing of the canvase (operational)
5. Monitoring condition (rectinity) of the back edge (in the initial state, current)
6. Grinding the back edge of the canvas (provision of rectinity)
7. Control of the intense condition of the web (in the initial state, the current)
8. Creating a normalized stress state (rolling and other)
9. Control of the intense condition of the canvas
10. Control of the state (wear) of the peaks of the teeth (current)
11. Sharpening teeth
12. Quality control of the preparation of teeth (operational)
Note 1: Operations marked with "+" sign are performed necessarily, "0" sign - if necessary.
It is necessary to remember and strictly observe the basic principle of preparation of tape saws - the gradualization of technological operations. In fact, each preparation operation is repeatedly performed by a closed cycle: control of the original or current state of the saw - the technological operation of the preparation - control of the performance of the operation - repetition of the technological operation in the corrected mode. Control of the initial or current state of the belt saw allows you to specify the amount of work necessary and adjust the mode of performing the technological operation for the entire web or its individual sections.
2. Technological operations in the preparation of cloths of new saws.
2.1 Preparation of cloths of new saws to sucked.
2.1.1 Remove rod roll saw.
Fig. 1. Development for unwinding the ribbon saw in the roll:
a - with clamps; b - with supporting rollers; in - with a horizontal rotating table; g - with outer tie (unwinding from within); 1 - base; 2 - Roll of belt band saw; 3 - clamp; 4 - lower supporting roller; 5 - Threaded rod; 6 - removable frame with rollers; 7 - rotating table; 8 - vertical roller; 9 - screed on the outer surface of the roll.
Roll unwinding from ribbon saws is carried out on the devices shown in Figure 1 (the device is applied under the item (b)). The use of such a device allows you to make the operation of the roll unwinding convenient and safe. Anticorrosion lubrication is removed from the cut of the web using scrapers. The residues of the lubricant are removed moistened in kerosene or solar oil with rags, then the canvas wipe dry.
Fig. 2: Diagram of connecting the ends of the band saw blades:
a - Marking of the ends of the cutting of the canvas; 1 - the left end of the canvas; 2 - the right end of the canvas; 3 - saw blade; 4 - The direction of the facets at the welding place of the saw blade.
2.1.2 Preparatory operations before welding
Preparatory operations are needed before welding (sticking) The preparatory operations: markup, cutting of the canvas in size along the saw length, bevel composite at the ends of the canvas. The markup scheme and parameters are determined according to Fig.2.
The value l \u003d (T + S) / 2, where the T-pitch of the tooth, mm; S-thickness saw, mm;
This formula is used for semi-automatic welding in a protective environment.
Such markup allows you to keep the teeth pitch at the connection site and ensure the favorable arrangement of welding (in the middle of the teeth). Next, put the square to the end of the saw, which is subject to segment so that one side of it exactly coincides with the saw back of the saw. The second working line of the square, we have half of the step (T / 2) from the top of one of the saws of the saw, and ride the cutting line of the saws.
Cut the end of the saw strictly by the marked line on the lever or on guillotine scissors. Cropped edges are filled with a file, cleaned girks. Perpendicularity is checked by the coal. Tolerance 0.05: 100 mm length. Place the length of the saw according to the drawing and, as well as in the first case, we apply the kit with one side to the back of the saw, and the other - at a distance of half the step from the top of the nearest tooth. We carry out the cutting line with a drain and cut off strictly along the line the second end of the saw on the lever scissors. We clean the burishes with a file and if you need to correct the cut so that the cut line is strictly perpendicular to the back of the saw.
2.2 Welding of cloths of new saws.
Currently, a welding semiautomatic model of the model is used to welding new saws: MIG - 107, it is possible to use a semiautoma of the model: BIMAX 152 Telwin-Italy. The welding unit is configured for welding of a saw of this sizes (the factory uses the German saws: B \u003d 130 mm, HRC \u003d 41 units., T \u003d 1.2 mm.) In accordance with the manual to the unit.
The saw prepared for welding, put on the table of the welding device with the back of the saw close to the stubborn planks of the table. Putting the fixtures together with the welding head must be collected on the hinges until it stopped. Tightly press the left side of the saw to the back to the stubborn table. The end of the saw should be located in the middle of the grooves at the base at the base of the copper plate (see Fig.3). The ends of the saws are moving away from stubborn slats by a value of 0.3-0.5 mm. The teeth are clever "0.
Fig. 3: Fixture for welding saw:
1, 7 - installation packs; 2 - saw blade; 3 - the gap between the ends of the canvas; 4 - clamping plank; 5 - electric heater (oven); 6.8 - gaskets for the installation of the gap; 9 - nuts fastening clamping slats
Setting up the welding unit is carried out in the following order:
a) insert into a special terminal clamp of the right clamping plate nozzle of the welding torch so that the distance from the saw is exemplary and the slope of the nozzle was 5¸7 ° \u200b\u200bthrough the welding (see Fig. 4). The welding wire should perform from the nozzle on 35 mm and is located in the middle of the seam.
b) to the back of the saw at the beginning of the welding site and to the teeth at the end of the welding site, it is close to put small pieces of the saw blade with dimensions of 10'10 mm.
c) distilling the welding burner to the start of the welding so that the end of the welding wire is above the applied plate.
d) we turn on the preheating of the saw and the colors of the breakdowns are observing the heated ends of the saw. After waiting, when the welded ends of the saws are warm to gray (250¸300 °), and the heating will be uniform in width, turn on the movement of the welding torch and the welding current button. Through the welder's shield, we observe the process of forming a seam.
e) After the welding is completed, turn off the movement button of the burner and the welding current button, inspect the seam and evaluate the quality (regulatory width of the seam 7 ¸ 8 mm). If there are minor sinks and irreversions, brewing these places.
And now we will give some welding modes:
Wire feed speed - mode 3 (1.5 cm / sec.)
Welding wire - Copyright D \u003d 0.8 mm. The supply of carbon dioxide is determined on test welding pieces of saws.
Fig. 4. Welding burner
2.3. Stripping welded seam.
After welding, the connection of the web must be cleaned. Tolerance to the sweep 0.05 mm, i.e. t \u003d 1,2 +/- 0.05 mm.
The cleaning of the connection on both sides of the canvas is performed with a longitudinal bending of the saw on a convex rubberized pattern using a grinding machine (pneumatic; electrical - model Casals Professional - Germany), then manually with a flat file (see Fig. 5).
Fig. 5. Speed \u200b\u200bshielding scheme: saw:
a - manual grinding machine; B - by means of a file; 1 - tile; 2 - ribbon saw; 3 - stand (100 mm height) on a rubber basis; 4 - grinding wheel; 5 - file; 6 - roller rollers.
To reduce the deformations of the connection sections, a flat grinding wheel is used with sizes æ152'3'22. Grinding is carried out by the periphery of the circle. At initial stripping, the rear edge of the canvas in the place of welding is also performed.
2.4 Annealing weld after welding.
The heat treatment of the weld begins immediately after stripping. Annealing welded seam We produce in a special slotted electric furnace. Now we give some recommendations on heat treatment seam:
a) The furnace before annealing saw is turned into an electrical network and is heated to a temperature T \u003d 350-400 ° C.
b) In heated to T \u003d 400 ° C, the furnace put the coiled saw so that the welded seam fit into the groove of the lower and upper half of the furnace.
c) the upper half of the electric furnace is closed and for better thermal insulation, the plane of the connector is making an asbestos cord.
d) The instrument of the pointer put a task to heat the spirals of the furnace to T \u003d 630-660 ° C and the shutter speed at this temperature 6-7 minutes. Include the oven with the "Anneal" button and are waiting for the specified time. After the assigned time, the furnace should automatically turn off.
e) After the heating is turned off, the temperature decreases in the furnace. Upon reaching the temperature T \u003d 350-400 ° C, the furnace can be opened, remove the saw and then cool it in air.
e) In the case of automation failure, the saw in manual mode is ignited by the same scheme: heating to T \u003d 630-660 ° C and shutter speed at this temperature is 6-7 minutes. Further, lifting asbestos cord, look at the colors of dealing on a saw. If the contour of the furnace on the protruding ends of the saw appeared a narrow dark blue strip on both sides of the saw, then the annealing can be considered complete if there are no breakdown colors, it is necessary to continue the heating until the dark blue stripes appear. Then the heating is turned off, cooled the saw together with the furnace to T \u003d 350-400 ° C, remove the saw from the furnace and cooled in air to the full cooling.
g) saws over 100 mm wide. It is recommended to flame in the flame of the gas burner. Annealing is carried out in the same thermal mode. The device where the saw is placed is heated by the flame of the burner to T \u003d 300 ° C, then placed the saw into the device, clamp and slowly heated to T \u003d 630-660 ° C, watching the colors of victim. The burner must be moved there and back so that the heating is uniform, and the saw did not breed. The duration of heating at T \u003d 660 ° C should be 7-10 minutes. Further, reducing the flame or removing the burner from the seam, gradually reduce the temperature to T \u003d 350-400 ° C, and then cooled the saw in the air. Such annealing should conduct an experienced welder, since it is necessary to determine the visual temperature of the annealing temperature in the color of passion.
According to the experimental experimental experiments (example, Vladimir), the annealing of the weld consists of the following:
Fast heating of the near-bed zone in a closed furnace to T \u003d 300 ° C for 1 min.
Heating from T \u003d 300 ° C to T \u003d 400 ° C for 3.5 minutes.
Cooling with T \u003d 400 ° C to T \u003d 390 ° C for 1 min.
Heating with T \u003d 390 ° C to T \u003d 405 ° C for 15 seconds.
Cooling with T \u003d 405 ° C to T \u003d 390 ° C for 30 seconds.
All ignition modes repeat 2 times.
Under annealing, recrystallization occurs - the formation of new grains. As a result of annealing, welding stresses decrease, and a fine-grained seam structure and a thermal influence zone, which has more stable and high plastic properties than a coarse-grained structure is formed.
2.5 Final stripping, editing and quality control.
The final cleaning of the compound zone is made by a petal grinding circle æ115'22. The last stage of processing the nearby zone is the slicing of the canvas from both sides until the color of the base metal is fine-grained skin. After stripping the connection of the web should be edited. Edit Connection is important for sawing. A properly refined connection and adjacent thermal influence zones must be completely flat when controlling the test plate (no more than 0.04 mm tolerance). The connection of the ribbon saw is ruled by the rolling due to the drawing of the tight zones located, as a rule, in the middle of the seam.
Circuits of the compound and controlling of flatness and stress state of the field of the web are given respectively in Fig.6 and 7. The prevail of the compound is manifested as the lumen of various shapes between the calibration line and the clove of the longitudinally curved saw. Footage of the rolling should be located at the points of contact line with the web, which are marked with chalk (marker). The processed portion of the canvas with a compound of 80¸100 mm long, which is noted by the transverse marks with chalk on the canvas (see Fig. 6). The execution of the edit of the connection of the rolling blade requires sufficient experience and a quick reaction from the toolman, since each length of the rolling rolletization is only 80¸100 mm.
Fig. 6.: Ribbon Saw Edge Scheme:
a, b - rolling; in, d - duty; 1 - welding seam; 2 - rolling tracks; 3 - transverse marks chalk; 4 - traces of blows with a hammer.
It is recommended to perform a rolling connection editing using the following techniques. The rolling machine is included (in our case, the PV-20M model), and the front transverse chalk line on the canvas is combined with roller rollers in the zone of the planned rolling track. The left hand turn the handle sharply - the upper roller is lowered (press), the resulting rulletination begins. When the rear transverse chalk line approaches the roller roller again, the handle is sharply turned sharply - the upper roller rises (pressed). The diagram of the rolling of the nearby zone is presented in Fig.8. At the calibration plate, the flatness of the canvas on the connection area is also performed.
Fig. 7.: Control circuit of the stressed state of the ribbon saw in the connection area:
a - diagram of the longitudinal bending of the canvas; b - r - the form of the transverse deflection of the canvas depending on the ingenuous state; 1 - stove; 2 - ribbon saw; 3 - calibration line; 4 - local lighting; 5 - rollers of the roller machine; 6 - location of the rolling rolling tracks.
Fig. 8. Shames of rolling of the nearby zone and the main canvas.
When the compound is rolling, as shown in the diagram (Fig. 8, a), the first traces are applied along the axis of the canvas, and then alternately one trace symmetrically centrally, one to the side of the toothed, the other toward the rear edges. The rolling rolling is carried out for 5 traces, the distance between which is 10 mm.
Low lengths should be edited by light blows of the cross hammer (Fig. 9, b), pre-laying a piece of paper. The strikes are carried out from the center of the Bugger to its edges, while the batche must be located with its elongated part or along, either across the canvas and never at an angle, since it causes twisting saw.
Fig. 9: A set of hammers for pivots and editing drank:
a - with a round brick b - with the cross position of the longitudinal slaves; B - with the oblique location of the longitudinal slaves
Regardless of the applied methods, the edit and stripping zone of the connection of the tape saw is carried out very carefully. In a qualitatively treated compound, the flatness must be higher than that of the rest of the saw blade. With a deviation from a flatness in the range of 0.1¸0.2 mm, the saw of the saw becomes short-lived. The ribbon saw with such a compound quickly flashes the liners of the guides at the band saw. To reduce the load on the connection of the tape saw in the teeth, adjacent to the junction, during subsequent preparation, the vertex broadening is not performed.
The quality indicators of the connection of the ribbon saw are the tensile strength, bending resistance, seam hardness and thermal influence zones, the thickness of the connection. In practice, limited to the control of the strength indicators and hardness of the connection. The durability and hardness indicators are determined on the blanks with a length of 100 mm, cut and the walls of the highest width saw. Bending tests before the appearance of cracks are performed in two ways (Fig. 10). According to the first method (Fig. 10, a), the sample is bent in visk with copiers, the sample is bent to the right and left 90 ° to the break. If there are no cracks on the sample, then the canvas is suitable for operation. As a reference, a sample is taken from the same canvas of the saw, heat-treated similarly to the welded pattern.
According to the second method, the sample is clamped in vice so that the middle coincides with the upper edge of the sponges (Fig. 10, b). Then the hammer blows are bended to the appearance of a crack (fracture). The seam is considered normal if the bend angle before the appearance of a og25 ° ¸30 ° is appeared. On the "Dzzz" practiced 1 method.
Fig. 10.: Connection test diagram of bending tape saw:
a - manually; b - with the help of a hammer; 1 - wooden handle with a slit slit; 2 - sample with a joint; 3 - center compound of sample (seam); 4 - steel copier; 5 - Pipes of plumbing; 6 - hammer; 7 is the position of the upper part of the canvas during a break.
2.6 Creating a stressed state in the canvas.
The normalized condition of the canvase increases the performance of the ribbon saw. The rolling rolling is the main way to create normalized residual stresses in the tape saw. To do this, also uses thermoplastic processing.
The tensile stresses created on the edges of the rolling blades provide a stable position on the machine pullees and in a cutlery when cutting wood, increased rigidity of the toothed edge, compensate for the temperature stresses arising on the gear edge of the saw during operation.
The stress state of the band saw blades is characterized by the indicators: 1) the sign, the value (arrow) and the shape of the transverse deflection in the circumference of the field of the web region, the fox section f; 2) curvilinearity (convex) of the back edge of the fields of the web located on the calibration plate - the M indicator.
The longitudinal bending of the web during the control of the stress state is performed on the "DZDS" in several ways (Fig. 11). Experienced tools The longitudinal bending of the canvas is checked when lifting the web site with left hand to a certain height, measurements are carried out with a right hand using a template line in the zone of the cloth of the cloth near the contact line of it with a calibration plate.
Fig. 11.: Control circuit of the stressed state of the canvas in terms of F with a longitudinal bending of saws: A - on the test plate with lining; b - on fixtal with pins; in - on a device with a radius pattern; 1 - saw blade; 2 - line; 3 - lining; 4 - the line of the beginning of the lifting of the canvas; 5 - calibration plate; 6 - lower pin; 7 - upper adjustable pin; 8 - base fixtures; 9 - Radius template.
Other methods of longitudinal bending of the canvase (Fig.12, B, B) allow you to provide a permanent radius of the longitudinal bending of the canvas in the measurement site F, so they are preferable. Also, the measurement of the indicator F is performed visually using templates and indicator lines (see Fig. 13, a - e).
Currently, the pulleys of the LLK-1 models of LK-1 models, LLK-2, began to produce on the "Dzzz" with the working part in the form of a sphere - this is due to the specifics of the sawing of the saw, the stable position of it on the pulleys. Taking into account the tilt of the pulley, the rear edge of the ribbon saws is lengthened, i.e. rolling the saw on the cone. The elongation of the back edge leads to its convexity, which is estimated by the indicator M.
Fig. 12.: Liners to control the stressed state of the ribbon saw by the F:
rulers - templates: a - with straightforward; b - convex; in - convex and concave edges; indicator rules; g - for measuring transverse concavity; d - with mobile supports; E - on the base of the caliper.
Approximate ribbon sawing technology, produced on the PV-20M model machine consists of the following steps:
a) Before the rolling of ribbon saws, the roller wear is checked with a radius of curvature R \u003d 105 mm. Moreover, the upper and lower rollers must have the same diameter (the difference is allowed in diameters not more than 0.02 mm) and the profile, otherwise the saw blade will be obtained in the form of convexity from the side adjacent to the larger diameter roller or with a large curvature radius in axial cross section. In case of unsatisfactory state of the working surface of roller rollers, it is necessary to perform a repairs consisting in the duct on the lathe and the subsequent refinement of the working surface of the roller with grinding by hand with a skin with control on the lumen on the pattern (Fig. 14).
b) the rolling of the canvas begins with the processing of near
width zones 120-130 mm, for which we put the welded and cleaned saw into a special device with a roller machine. Saw teeth located from the machine, the slope of the teeth - against the movement of the saw.
Fig. 13.: Control of the profile of the working surface of the roller roller on the lumen by the template:
1 - mandrel; 2 - roller roller; 3 - template.
c) rolling rollers along the length of the canvas start with its middle, and then alternately from its middle on both sides of the midline. The scheme of the passage of the passages, the valgesting force for the near-bed zone and the main belt of the belt saw (Fig. 8).
d) The pressure of the rollers is reduced also symmetrically from the middle to the edges of the canvas. As a result of such a rolling, the stretching of the middle part is evenly decreasing to the edges of the saw, and the internal stresses on the edges are the same by the sign and are equal in size. The control is carried out by the application of the calibration line across the curved canvas along the entire length of the saw. The value of the bending of the saw should be the same in all places of measurements and equal to the radius of the sphere of sawing pulleys (see Fig. 16). As can be seen from the diagram, the optimal clearance for our saws should be in the range of 0.2 - 0.3 mm.
It is impossible to allow the part of the canvas adjacent to the front edge, were not excessively small residual internal tension voltages. In this case, the saw will wander in propylene and strive to break off the pulleys. Correctly failed saw should be completely flat in an unsubstantiated state. When applying to the calibration plate, the saw should be removed without squinting over the entire length. The front and rear edges should have the same stretching voltage over the entire length.
Alignment operation, i.e., the elimination of defects should be performed consistently in some sections of a saw length up to 1m. Having finished the processing of one section, you should begin the rolling of the following. The allowable beating of the saw on the pulleys should not be more than 1-2 mm / r. According to Vladimir experience, the maximum deflection of the saw along the entire length of the canvas is 0.20.3 mm £ 0.4 mm. The concave of the rear edge of the saw is not allowed.
Fig. 14. Saw Pulley Profile Chart
e) the rolling results are checked using the calibration line sequentially on each meter of the web.
Note 1: Recommendations of foreign firms for ribbon saws are close to domestic and reduced to the following: the rolling is starting with the middle line of the canvas with the greatest effort; Subsequent rolling traces are applied symmetrically central with a gradual decrease in climbing clips (according to the saw pulley profile); The distance between the traces should be within 10 ... 20 mm; The extreme traces of the rolling should be located not closer than 20 mm from the line of the teeth of the teeth and the back edge of the canvas. The stressful state, as well as the flatness of the rolled new saws, is monitored after idling on the ribbon for 30 minutes.
2.7 Preparation of teeth belt saw
2.7.1 General information on the preparation of teeth
Preparation of ribbon saw teeth allows you to provide sawing wood with the smallest energy consumption and consists of two main operations - sharpening and revenues. After spitches, the peaks of the teeth are molded and their side sharpening is performed. At the factory, the preparation of the teeth is performed in the following sequence: new saws - black shoes in profiling mode, cloth rolling, 1 ... 2 passage in pure sharpening mode, ivy, molding, final sharpening, subwinding.
The black shoes of the new saws, or the stratification of the defective layer formed during the notch, ranging from 1 to 1.5 the thickness of the web, is carried out with the following objectives: ensure the compliance of the teeth profile of a specific sharpening machine and to create conditions for accurately removing the small layer during final finishing sharpening; eliminate the negative effect of notches on cracking when spitting the peaks and during operation - in the depressions of the teeth; To remove the compressive stresses from the notches in the teeth, which allows you to create the necessary conditions for the subsequent rolling of the canvas and prevent an unstable state of changing the stress state of the canvas when it is rated in width.
During operation, the active contour of the peaks of the teeth is wears. The vertices of triangled corners and the main cutting edge are most intensively. Due to wear, the microgeometry of teeth vertices changes and their cutting ability is lost. The disjunction degree is determined by the deterioration of the quality of sawing, an increase in cutting power and feed force. Directly on the saw, the degree of blinks in production conditions are determined by the highlights of light, reflected from the shut-off vertices.
Since the gear edge of the saw is a complex profile consisting of conjugated curvilinear and rectilinear areas, for removing metal with a thin surface, it is necessary that the combination of movements of the grinding wheel and saws can provide a relative trajectory that repeats the shape of the teeth profile. Grinding is performed with a combination of 2 movements: returnable whether the oscillatory movement of the grinding head parallel to the front edge of the teeth and the periodic supply of the saw into the teeth is parallel to its longitudinal axis.
2.7.2 Preliminary sharpening ribbon saws
a) The main purpose of pre-sharpening is to prepare the teeth of the saw to blast.
b) the rough and finishing sharpening is carried out on a sharpening machine tool of the model TCL-2 (processing on TCPA-7 is possible). This is a universal type of machines designed for sharpening drank different types (round, frame, tape). Such machines operate with side grip and supply to a sharpened tooth, while the non-uniformity of the step on the saw does not interfere with the uniform removal of metal from the front edge of the teeth (see Fig. 15). The sharpening head is rotated by an angle of 26 °.
Fig. 15. The scheme of the asymmetric installation of the sharpening machine:
1 - sharpening machine; 2 - single support under grinding circle; 3 - ribbon saw; 4 - right roller support; 5 - single roller support; 6 - Machine for lateral sharpening teeth
c) Sharpening modes of tape saws are indicated in Table 2. Table 2
Ribbon saw sharpening modes
Operation
Double number
grinding moves
heads per minute
Cutting to the passage for passage, mm, on the verge
passages
front
Profiling (Draft Shark)
Before forming profile
Sharpening after ivy
Clear sharpening
Podshlifovka
Without feed
In order to avoid the unevenness of the groove of the teeth along the length of the saw, it is necessary to adjust the mounting of the grinding circle only once for a full turn of the saw. If necessary, grinding circles are balanced in accordance with GOST 3060 - 75 "Grinding circles. Permissible unbalanced masses and method of measuring. " At the enterprise, the circles are balanced with the help of simplest devices representing an mandrel on supports. Supports can be prisms, discs and rollers. It is permissible to be used under the condition for strict parallelism and perpendicularity. After completion of the sharpening of the teeth, the burrs, located in the zone of inter-nodes, are removed by the scraper, grinding bars or a triangular file, moved along the gear crown. Transverse movements are not allowed. Grinding wheels in the process of sharpening wear out, lose the initial profile, it is also possible to blunt and "sucking". When performing all the sharpening operations for teeth on the profile and from the side of the side faces, grinding circles are necessary to periodically rule with a diamond pencil, correcting the work part of the bar of the bar. All this is performed in order to obtain profiles with maximum radii of interdental depression and elimination of "insulation". In fact, the grinding wheel requires periodic sharpeners. Grinding circles usually rule:
a) running with abrasive, carbide and metal discs, pencils;
b) with a diamond instrument;
c) grinding with green silicon carbide (Fig.16).
At the "Dzzz", the edit of the circle is carried out according to the method A).
Fig. 16.: Edit Grinding Circles:
a - scraping; b - running; in grinding.
2.7.3 Requirement and molding of teeth drank.
At the "Dzzz", the spokeshes of teeth of new saws are carried out for 3 passages: the first two passages are carried out on the machine of the PCFLB model for the cold spills of the teeth, released by the Kirov Machine-Plant Plant. After such rally, it turns out a tooth with broadening for each side of 0.6 ... 1.1 mm, and the smallest value - for thin saws and solid rocks. This machine works on a semi-automatic cycle. The teeth of the new saw before osses should be straightened with the control of the indicator divorce and are pre-sharpened.
Before the blasting of the saws, the saws should be applied to a lubricant consisting of 50% autolant and 50% of solidol (substitute - grate-lubricant "F").
The third pass (final) is carried out on the Pi-34-1 model plot made on the "Dzzz". Here are some recommendations in the order of work with a feller:
a) The plot is put on the saw, then adjustable the position of the stubborn and clamping screws of the plot of the pivot, so that when turning the handle of the clamping screw to themselves, the saw blade turned out to be clamped exactly in the middle of the hull slot.
b) Next, we establish a plush roller on a given broadening of ivy. This is achieved by the reversal of the sector regarding the handle of the plillant roller, and then the turning roller turns on the handle on the handle.
c) When the flattek is installed onto the tooth, it is held with the right hand behind the bracket handle and presses forward until the roller stops into the front line of the flattened tooth. The bracket of the handle bracket must be pressed by the peaks of the teeth. Then it is cleaned with a saw tooth, the spool handle turns from the clamp of the saw and the arm of the bracket is rearranged on the next tooth.
d) With the wear, the plush roller must be moved in the axial direction by the amount of wear, and the end of the anvil as wear is sublipped. The magnitude of the teeth broadening for new saws is set to 0.85 × 1.2 ± 0.2 mm (see Fig. 17).
Possible defects of rally and molding methods for their elimination are discussed below. Asymmetric (unilateral) revenue occurs in oblique sharpening of the faces of the teeth, which is descended due to non-perpendicular to the plane of the grinding wheel to the side surface of the saw blade at sharpening, and with non-perpendicularity of the side surface of the saw to the longitudinal axis of the pivotal roller and the supporting surface of the oscillation.
The bing of the tip of the tooth up occurs due to a loose touch of the back edge and the supporting surface of the cavity due to the distortion of the profile of the tooth when sharpening with the formation of the bulge or concave rear face, as well as the incorrect refueling (angle) of the working surface of the cavity (see Fig.18).
0,85 ¸ 1,2± 0.2 mm
Fig.18.: Scheme of the arrangement of the cavity of the tooth
You can exclude these defects with an alignment and setting of the mutual layout of the saw blade, a plusty roller and an oskovaleniki, refueling of the cavities, subwinding the working surfaces of the oscillation and the plurality roller. Partially some flaw defects correct or eliminate when molding.
Fig. 19.: The shape of the top of the tooth: A - after the correct; B, in - after incorrect ivy.
The shape of the teeth saws is carried out on manual forming of the type PI - 35, manufactured in a set with a pi-34 flattener - 1. Forming for the formation of flattened teeth of the teeth of the saws. At the same time, the process is achieved leveling the value of the vanes of the teeth and the formation of the angles of undercut.
During operation, the molding is supported by an left hand for a wooden lining and cheek, the handle rotates with his right hand. When dressing molding on a saw saw, the handle must be reserved forward. The molding is put on the top of the teeth and slightly plaspacing to contact with the front of the tooth. When removing the handles back, the planks are moved out, freeing the tooth. The extension of the teeth blade is measured by an indicator divorce or micrometer.
For the new saw, it is recommended that the magnitude of the exhaustion is recommended within 0.6 ¸ 0.9 ± 0.1 mm. All siping teeth should be molded the same in both directions, the tip of the tooth should not have a fill. Digits and cracks are not allowed. The shape of the spatula after ivy and molding must match the figure (see Fig.20).
Fig. 20.: Form of the tooth of the ribbon saw after ivy.
Fig. 21. The shape of the tooth of the ribbon saw after molding
a) the minimum breakage of saws for 2,35 mm;
b) rally and molding should be strictly symmetrical relative to the saw axis;
c) the tooth is flattened to no less than six times;
d) tolerance for deviation from the size of ilob and molding 0.05 mm per side;
e) Size after ovychy: 3,15¸3.25 mm, size after molding 2.55¸2.65 mm.
2.7.4 Fugging Tooth Saws After Iquishment and Molding
The teeth saw a fugue for alignment in height and the width of the divorce, that is, to ensure the normal operation of the saw.
The fuggling of the ribbon saws is performed by hand the flat personal file or donel fixed in a special holder. For alignment of minor deviations of molding, fugurate and side sides of the teeth saw. The lateral seifuge teeth is allowed only in minor sizes in the limit of 0.05 ¸ 0.15 mm.
2.7.5 Final Sharpening Tooth Saw
After the fugification of the teeth, the saw finally sharpened. Three folding methods are distinguished: the first - part of the metal from the front edge of the tooth; The second is from the back of the tooth; Third - simultaneously with the front and rear faces. The third method is most rational, and therefore is most common. The sharpening is also carried out on the Machine model of the TCL - 2.
Sharpening It is recommended to conduct a circle on a bakelite basis, the hardness "C" and the grain of 80¸100 units per one - two passages. At the same time, the stuffed surface is grinning with minimal chip removal: a depth of no more than 0.01 mm. The cutting speed is recommended 22¸25 m / s, the thickness of the circle is at least 10 mm, so that the radius of the rounding was at least 5 mm.
To improve the quality of sharpening, it is recommended to additionally subwind the teeth manually with fine-grained donkey fixed in a special holder. Led with a donkey need from bottom to top, pressing it to the stuffed face. Podliliovka remove small burgers, roughness of sharpening and risks, which increases the resistance of the saw by 15¸20% and improves the quality of the propyl.
Final sharpening must meet the following requirements:
a) all teeth must have the same profile, i.e. the same step, height, corners and other parameters;
b) the peaks of the teeth should be located on one straight line;
c) The bottom of the pripadine between the teeth should have a smooth rounding. Sharp corners are unacceptable.
d) the teeth of the saw should not have crochets, dorms and pretending the tips, burrs on the edges and other defects;
e) the front cutting edge of the teeth should be perpendicular to the side plane of the saw;
e) sharpened teeth should not have a brilliance on the corners formed by the intersection of the edges. Glitter testifies to unleashed areas;
g) on \u200b\u200bthe edges of the teeth and the bottom of the depression should not be visible rice, since they are concentrates of local stresses.
h) The sharpened saw is slightly lubricated with a cotton swab, moistened with machinery on both sides, to relieve in two places with linen twine, and in such a position in the warehouse.
2.8 Installation of saws on the machine and repair saw.
Ribbon saws are chosen based on the parameters of the band saw. The thickness of the ribbon saw should be 0.0007 ... 0.001 diameter of the saw pulley. The ribbon saw on the machine should be stretched with an effort that provides the necessary rigidity of the canvas.
Saws are installed on the pulleys, so that the depressions of the teeth protrude beyond the edge of the pulley at 5 ... 10 mm. After tensioning the saw and the short-term activation of the cutting mechanism (until the stabilization of the saw position during its idle operation), if necessary, adjust the tilt of the upper pulley. The final position of the saws on the pulleys is controlled by a ruler. Hosting saw saw is 30 minutes. Next, the flatness, the beating of the rear edge and the rigidity of the saw blade in the cutting zone are checked.
When sawing the resinous wood, water or air cooling and sawing saw is used. Always in good condition there should be scrapers on pulleys and a wooden jackhambing bar, which prevents falling out of sawdust between the saw and the lower pulley of the machine.
Repair of ribbon saws includes the following operations:
a) spent saw to hang on the rolling stand;
b) solar chopped with a sip of sawing;
e) Maintainable saws ³65mm wide from the gear edge and the crack length L £ Lpila / 2, where Lpilas - the length of the saw.
d) check the presence of cracks in the depression of the tooth and on the back of the saw. If there are cracks, then you need to put the hole in a depth of 0.1¸0.2 mm at the end of the crack. In the case of a crack ³ 35 mm, it is brewed on a welding semiautomatic. Next, the rolling saw is made according to the valgestion of the nearby zone.
e) check the transverse bending of the saw, if the deflection is £ 0.3, then the saw must be failed (2¸3 of the track, the maximum load of the rolling on the saws of the German 14¸15 atm.
e) Saw tooth springs are controlled: the minimum value for sharpening is 2.35 mm, if the value< 2,35 мм, то зубчатая кромка срезается и плющится заново.
22.05.2015
Appointment and types of ribbon saws
Ribbon saws are a cutting tool of band sawing machines: carpentry, dividing and logs. The saws used in these machines differ only with dimensions, the profile of the teeth and are divided into three types: carpentry (narrow), divisory (medium) and log (wide). The first two species are produced according to GOST 6532-53, and the log-in-line - according to GOST 10670-63 "Belt saws for sawing logs and BRUSEV". Ribbon saws are used for curvilinear and longitudinal sawmills of boards, bars, logs and slab wood materials.
Construction of tape saws
The design of the band saws is characterized by the size of the canvas (width in the tape, including the teeth, 5, long L), the profile and the size of the cutting edge teeth. The dimensions of the band saws mainly depend on the design of band sawing machines: the distances between the axes of the saw pulleys k, their diameter D and width.
Length of a belt saw can be determined by the formula
Since the tape is supplied by the rollover in rolls, when circumcised the calculated length, it is necessary to take into account the allowance for the spike, and in the place of the spike to withstand the total teeth.
Tape saw thickness depends on the diameter of the saw pulley and must satisfy the dependencies
From the ratio of the thickness of the saw and the diameter of the pulley, the value of bending stresses depends, which in the general balance of stresses have a great specific value. The magnitude of the tension from the bending saw
The magnitude of the bending voltage at S / D \u003d 0.001 will be
The temporary resistance of the rupture in the place of the spike does not exceed 70-80 kgf / mm2. Therefore, with a minimum strength of strength, equal to 2, voltage in a working saw should be less than 35-40 kgf / mm2. In this regard, they seek to use the minimum possible thickness of the saw and large diameters of saw pulleys.
The width of the belt band saws depends on the width of the saws and can exceed the last only to the height of the teeth. Choosing the width of the joinery ribbon saw when drinking curvilinear parts, it is additionally necessary to take into account the radius of the curvature R mm propyl and the broadening of the teeth on the side ΔS mm. Then the width of the saw
Wider saws will bend in cross section, which will result in their slaughter and even slipping from pulleys.
Lobzic machines are used to cut the details with a very small radius of curvature, in which fuel saws are used as a cutting tool. The size of the jigsaw saws L \u003d 130/140 mm, B \u003d 2.3 / 8 mm, S \u003d 0.26 / 0.5 mm, T \u003d 0.6 / 1.5 mm. The angular parameters of the tooth with a straight rear face: α \u003d 5/10 °, β \u003d 40/45 °. The dimensions of joinery, dividing and log-ribbons saws are given in Table. 25
For each type, the saw of GOST has its own tooth profile. For example, for divisory drank two: profile I - with an elongated depression and profile II - with a straight rear edge (Fig. 41.6). Dimensional saws with a tooth profile I are used in sawing solid and frozen soft rocks, with a tooth profile II - when sawing soft wood. The dimensions of the teeth tape saws depend on their thickness, widths and cutting conditions.
For carbon frame saws, a width of 10-60 mm sizes of teeth are determined by the following approximate expressions (mm):
For splitting and logs of ribbon saws, teeth sizes are equal (mm):
For saws with a diluted tooth, a step is reduced by 25-30%. The angular values \u200b\u200bof the teeth profiles provided by GOST are shown in Fig. 41. The front corner of the teeth must be done as large as possible, since in this case the power to cut the power to cut and decreases the pressure force in the horizontal plane, which shifting the saw from the pulley. However, with an increase in the front angle Γ, it is necessary to take into account the properties of the sawn material and the strength of the tooth, depending on its size and the alarm angle β. The angle γ should withstand within 20-35 °.
Spike tape saw
Spike tape saws is performed in the case of the preparation of new saws from the roll tape, the repair saw in the presence of significant cracks (more than 0.12V) or the cliff. It includes the following operations: markup, trimming, lighting, spawning, heat treatment of the paved seam, his sweeping and editing. With proper spike, it is necessary that the seams are at half the distance between the vertices of the adjacent teeth of the paved saw. To do this, in front of the trimming saw, it is placed using a ruler, cooled and blacks.
Marking and cutting of defective places (when repairing saws) you need to do according to the scheme shown in Fig. 42. The width of the seam depends on the thickness of the saw s and is approximately taken equal to 105. After the saw markup is cut according to the outlined AB and CD lines with scissors or chisels. The cropped ends straighten the hammer on the anvil and cleaned with a file. The ends of the saw solder the penetration. To keep the thickness of the soldered seam equal to the thickness of the saw, the ends are mounted (remove the chamfer) within the lane marked. Removing the champers is performed by hand the file on a special device, or on milling or sharpening machines. The captured ends thoroughly cleaned with sandpaper and degrease.
The ends of the saws are soldered in special presss with solder bars, electric soldering devices of a flame of a soldering lamp. Press with solder bars are heated to 830-1000 ° C in PM-6 muffle furnaces. The ends of the soldered saws are installed in a soldering press, and between them are packed in the form of a plate with a thickness of 0.075-0.15 mm together with a flux - dehydrated drone. Flux is necessary to protect soldered surfaces from oxidation, as well as their best wetting. Then the heated soldering bars are inserted into the press and tightly with the help of the screws are pressed to the spike place. After moltening the solder and cooling of bars to dark red, they are removed, and the spike place is cooled in the cold section of the press. After some time, the saw is subjected to leave for 1-2 minutes with the same bars, but heated already up to a temperature of 650-700 ° C. For soldering, silver solders of P-CP-45, P-CP-65 or brass L62 are used with temperature Melting 605-905 ° C. After cooling, the place of the spikes are cleaned from the scale and is reduced from both sides by a personal file to thickness equal to the thickness of the saw blade. Then the place of the spike rollery.
To connect the ends of the tape, you can use the method of butt electrical welding using the ASLP-1 devices. The ends of the saw at the same time are trimmed at an angle of 90 ° C, secured in the clips of the welding machine, lead to contact and include the current. As soon as the ends of the saw are heated to the plastic state, the current is turned off, and the ends saw the clips moving even more tightly to the welding them. This method has not yet received widespread use, as special equipment is required for it.
Edit and ribbon ribbon saw
For edit Ribbon saws detect and eliminate defects as well as when editing frame saws. Given the larger length of the saw and their small thickness, eliminate defects with great thoroughness, mainly with the help of a roller machine. The smaller the ribbon saw is exposed to correct hammers, the more service life. Therefore, to edit, it should be resorted in case of extreme necessity, if possible, replacing it with rolling.
Rolling Ribbon saws are performed in two ways.
The first method: The symmetric rolling is performed like a frame of frame saw and lies in the elongation of the middle part of the web (Fig. 43, a). Start rolling from the middle part of the canvas and finish, not reaching 10-15 mm on the one hand to the line of depression of the teeth, on the other - to the rear edge of the saw. Rolling, editing and quality control of saw preparations are accommodated on special tables equipped with a roller machine, anvil, check stove and supporting rollers to move the saw. The degree of rolling is determined by the arrow of the transverse curvature during bending of the saw using a short verification line. The deflection boom should be approximately 0.2-0.4 mm for pulleys with a direct rim and 0.3-0.5 mm - with convex. Big values \u200b\u200bof the deflection are more and thin ribbon saws. Accurate checking of the transverse saw saw can be carried out by a convex template with a radius of curvature corresponding to a properly treated saw. In addition, they check the straightness of the rear edge of the saw by placing it on the test flat plate and applying to the edge of the long straight line.
The second method of ribbon saws is called rolling on the cone (Fig. 43, b). Rolling start at a distance of 15-20 mm from the line of the pripadine teeth. Closer to the rear edge of the pressure saw rollers increase. The last trail of roller rollers should be located within 10 mm from the rear edge. As a result, the cutting edge turns out to be shorter than the rear and the tension receives high stresses than the other parts of the saw. The rear edge of the saw treated by the rolling method on the cone and put on a flat check plate, will be located on an arc of a circle with a center placed in the direction of the teeth. The magnitude of the bulge of this edge at a length of 1 m serves as a characteristic of the degree of rolling. The arrow of the convexity is determined by the test line with the indicator along the entire length of the saw. The embossing arrow should be 0.3-0.5 mm at a length of 1 m, and the greater values \u200b\u200brefer to wider saws. If part of the canvas in the length of the saws, the convexity is larger than the required, this place must be failed with increasing pressing of rollers from the rear edge to the cutting. On the contrary, if the bulge is small, roller with an increase in the pressure of the rollers from the cutting edge to the rear. The second method of rolling is the best for wide band saws, especially with uneven heating in the width of the canvas.
Installation of ribbon saw into the machine
The normal operation of the band sawing machine depends not only on the quality of the saw preparation, but also its proper tension and installation in the machine. To do this, the following conditions must be completed:
1. The ribbon saw in the installation process and work should be so placed on the saw pulleys so that the cutting edge performs for the edge of the pulleys at least than half the height of the tooth, but not more than its height.
2. The saw tension should be sufficient to ensure its stiffness in the side direction and on average to be at least 5-6 kgf / mm2.
3. The guide machines for the saw should be driven and adjusted by a saw with a gap not exceeding 0.1-0.15 mm.
To exclude the displacement of the saw tape on the pulley due to the horizontal components of cutting efforts, the incomprehension of the resultant tension of the saw from its middle line, the heating of the saw, etc. apply a number of preventive measures. The saw pulleys are made with convex rims, while the bulges are not in their middle, and closer by 25-40 mm to the cutting edge. Flat pulleys to exclude ribbon slips tilted (on a working) relative to the horizontal axis at an angle of 10-15 ", and saws rolled to the cone. In addition, most of the modern machines allows you to deploy the upper pulley around its vertical axis due to the side shift of the front support of the pulley shaft. Such a turn (working branch outside) allows you to hold the saw with a strong heating and cutting into the inner side. The guide machines make it possible to protect the saw from strong side bends, sliding with pulleys and extinguish resonant fluctuations. In the process of work, it is necessary to closely monitor the purity of saw pulleys, timely cleaning them from dust, sawdust, resin, etc.
Technical requirements for tape saws
The limit deviations of the sizes of ribbon saws should not exceed the values \u200b\u200bspecified in Table. 26.
The roughness of the side surfaces saw should be not lower than the 7th grade according to GOST 2283-57. Cracks, bundles, scratches, burns from grinding are not allowed. The canvas should be straightened and evenly failed. On a saw every 10 m should be a stamp indicating the type of saw, its size, GOST. For example, for log-ribbon band saws according to the scheme: "PILL PLS BXSHT GOST 10670-63".