Rolling machine for ribbon saws. Services for the repair of wide band saws Installation of tape saws: Methods of tension, guide devices, adjustment of pulleys
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 by 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.
The presence of a complete set of equipment, devices and a control and measuring instrument is the first condition required when ribbon sawing rolling.
It is also necessary to estimate the technical condition of the equipment used, that is, to identify defects and, if necessary, bring it to a state corresponding to the values \u200b\u200bof accuracy.
When visiting the enterprises, the author often recorded the absence of some devices and measuring instruments or the unsatisfactory state of the equipment used and, accordingly, the unsuccessful taste of ribbon sawing rolling.
For example, one "craftsman" tried to fad tape saws in the absence of a pressure gauge on the rolpetnochnaya machine. The other company showed a radial and axial backlash roller. The reason is the wear of the bronze sleeve due to the notions of the lubricant. These two cases refer to explicit violations, but there are also hidden defects of used technicians who are quite difficult to reveal.
Equipment, fixtures and measuring instrument for rolling of wide tape saws
The set for shading of wide tape saws includes the following:
- aggregate (workbench) for the preparation of ribbon saws (preferably double-sided), including a rolling machine, a test plate with a length of at least 1.5 m, a flat anvil, a block of lifting rollers and a device for grinding the rear edge of the band saw blade;
- a set of proper hammers, including a hammer with a round bobbin, a hammer with a cross-arrangement of longitudinal brine and a hammer with an oblique location of longitudinal brisk;
- a set of lines to control both flatness of the canvas and straightness (bulge) of the rear edge of the band saw blade;
- a set of templates and lines, including the indicator, to control the strenuous state (degree of rolling) of the canvas.
It is appropriate to recall once again that the absence of any element from the above will not allow quality rollanting.
The standard equipment of the unit for the preparation of tape saws does not provide for the supply of the lifting block and the device for grinding the back edge. Therefore, they need to be made and mounted independently.
The lifting roller block is installed in the immediate vicinity of the roller machine and serves to eliminate the transverse bending (gutter) of the band saw blade.
The device for grinding the rear edge of the canvas is an electric motor with a grinding circle, mounted on a sled in the horizontal plane behind the calibration plate. This device is aligned with the rear edge, that is, eliminate its local waviness. This is a very important, prior to the rolling of the canvas operation, which will continue to high-quality cloth rolling on the cone and sharpening of the teeth.
Detection of defects and assessment of the technical condition of equipment for the rolling of wide tape saws
First of all, it is required to estimate the technical condition of the roller machine, even if it is new. Practices say: "Why evaluate the technical condition of the new roller machine?". The author was found new rolling machines, in which the mutual location of roller rollers was unsatisfactory. Therefore, it is necessary to check even the new roller machine.
Methods for assessing the technical condition of the roller machine and its installation on the unit for the preparation of tape saws are indicated in the table.
| No. p / p | Controlled indicator | Permissible deviation, mM. |
Tool and control method |
| 1 | Diameter of roller rollers (upper and lower) | 0,02 | Micrometer. Controlling the difference of diameters of roller rollers |
| 2 | Parallelity of the axes of roller rollers in a horizontal plane | 2 (at a length of 1000 mm) | On the shafts of roller rollers, arrows are 500 mm long. In the right position, the arrow should be closed, then the arrows rotate left. The resulting clearance is measured |
| 3 | Parallelism of the axes of roller rollers in the vertical plane | 2 (at a length of 1000 mm) | Arrows are used according to claim 2, which are installed alternately vertically first into the upper position, then to the lower position. The deviation from the plumb is measured |
| 4 | Radial beating of the working surface of the upper and lower roller rollers | 0,01 | Magnetic rack with a clockwise indicator |
| 5 | Hardness of the working surface of the upper and lower roller | 2hrc. | Hardness |
| 6 | The size of the large axis of the ellipses formed in the form of an imprint on the plate from the top and bottom side | 5,0 |
A copper or aluminum plate is compressed between rollers rollers. The pressure is removed and measured by the caliper of the large axes of ellipses from the formal fingerprints (writing) |
| 7 | Parallel to the surface of the table plate sided in rollers, on which the rolling machine is installed | 2 (at length 200 mm) | A flat plate 300x200 mm made from the saw blade between the rollers. Shatnerraismus is measured by the difference between the distances between the edges of the plate and the surface of the table plate on which the rolling machine is installed |
| 8 | Radius of the working surface of roller rollers in the axial section | Radius pattern | |
| 9 | Estimation of the condition of the working surface of roller rollers | Visual control with a loupe for the presence of dents, chips and other damage | |
| 10 | Installation of working surfaces of calibration plates, anvil and lower roller roller in one horizontal plane | 0,1 | For control and installation uses a calibration line 2 m long |
Please note that the rating in terms of 6 and 7 is the indirect control of the state of roller rollers and their mutual location, but is quite sufficient for the ribbon ribbon practitioner.
To perform checks in terms of 8, a radius pattern is manufactured, which is a part of the ring, isted on the lathe. The lumen between the working surface of the roller roller and the template indicates wear or plastic deformation of the working surface of the roller roller and the need for its perch.
When evaluating the condition of the working surface of the roller roller (indicator 9), it is necessary to pay attention to the risks, dents, chips and other damage - they are not allowed.
An integral (general) assessment of the good technical condition of the roller machine and its proper installation on the unit for the preparation of ribbon saws is the flatness of the band saw blade, that is, after the rolling of residual deformation of the web, leading to the loss of flatness of the band saw blades.
Of course, the identification of defects for equipment for ribbon ducts - a rather complicated work and requires certain skills and practices.
I hope that the material presented in the article will help technical professionals in doing this work. If necessary, you can refer to the author for advice and technical assistance.
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