Broach equipment

Abstract

The utility model provides broach equipment which comprises a broach body, a broach handle and a broach handle. The outline of the outer circle of each grinding wheel is matched with the groove shape of the cutter body; the screw penetrates through an inner hole of the grinding wheel to fasten the grinding wheel on the end face of the flange of the cutter bar; and the cutter bar is used for connecting, fixing and transmitting the torque of the main shaft. The broaching tool equipment improves the machining precision of the broaching tooth groove, has the advantages of being high in tooth groove machining precision and efficiency and long in service life of the grinding wheel, and can meet the actual requirements for machining the spiral tooth groove of the broaching tool in a high-precision, high-efficiency and low-cost mode.

Description

[Technical field]

[0001] The utility model relates to the technical field of broach manufacturing, in particular to a broach equipment. [Background technology]

[0002] A broach is a tool used to process the inner hole or outer cylindrical surface of a gear. The tool body is provided with spiral tooth grooves that match the gear rack. The gear is processed by the spiral motion of the tool and the workpiece. The tooth grooves are multiple tooth grooves distributed along the spiral line on the tool body of the broach. Their shape matches the gear rack. They are used to accommodate the chips generated when processing the gear and provide a guiding function for the tool and the workpiece. The shape, size, helix angle and other parameters of the tooth groove directly determine the cutting performance and processing accuracy of the broach.

[0003] Broaches (or tooth grooves) are mainly used for:

[0004] Gear broaching: This is the main purpose of the broach. Through the spiral insertion movement of the broach and the blank, a rack that matches the shape of the broaching groove can be machined on the inner hole or outer surface of the gear blank. The precision of the spur gear processed by broaching can reach 7-8 levels, with high production efficiency, and is suitable for mass production of small and medium module gears.

[0005] Worm and turbine processing: The spiral tooth grooves that match the spiral surface of the worm and turbine are processed on the broach. Through the broaching movement, high-precision worms and turbines can be processed. The worm processed by this internal drawing method has high transmission efficiency and good meshing performance, and is suitable for high-precision transmission occasions.

[0006] Other spiral surface processing: For other workpieces with spiral surfaces such as augers, spiral drill bits, spiral milling cutters, etc., they can also be processed using special broaches with tooth groove profiles that match them. Compared with hobbing, milling and other methods, broaching can achieve higher surface accuracy and surface quality.

[0007] In addition to the common uses mentioned above, broaches can also be designed into different shapes according to special processing requirements and used to process special surfaces. For example, by processing special-shaped broaching grooves on the broach that match the non-circular gear rack, the broaching of non-circular gears can be achieved.

[0008] However, the tooth groove structure is special and is limited by the conditions of equipment, machine tools, tool bars, grinding wheels, broach structures, etc. during processing. The processing is complicated and it is difficult to complete high-precision processing using existing processing methods. [Contents of the utility model]

[0009] In view of the shortcomings of the prior art, the purpose of this application is to provide a broaching device, which improves the processing accuracy of broaching tooth grooves, has the advantages of high tooth groove processing accuracy, high efficiency, and long grinding wheel service life, and can meet the actual needs of high-precision, high-efficiency, and low-cost processing of broaching tooth grooves.

[0010] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0011] A broaching device, comprising:

[0012] A knife body, wherein the knife body has a plurality of grooves distributed longitudinally;

[0013] A plurality of special-shaped grinding wheels, the outer contour of which matches the groove of the cutter body;

[0014] A screw passes through the inner hole of the grinding wheel to fasten the grinding wheel to the flange end surface of the tool rod;

[0015] The tool rod is used for connecting, fixing and transmitting the main shaft torque.

[0016] The utility model is further configured as follows: the plurality of grooves of the blade body are special-shaped grooves, the cross-sectional profiles of the plurality of grooves present multiple arcs or curves, and a convex portion is left between two adjacent grooves.

[0017] The utility model is further configured as follows: the grooves on the cutter body have a certain helical angle and are distributed in a spiral shape around the central axis of the cutter body.

[0018] The utility model is further configured as follows: the blade body has a first groove and a second groove, the first groove is in an arc shape at the bottom, the two sides are connected by oblique straight lines and arcs, and the top is in an arc shape; the arc radius of the top of the second groove is smaller than that of the first groove.

[0019] The utility model is further configured as follows: the special-shaped grinding wheel pieces are at least two pieces of waste grinding wheel pieces, the inner holes of the grinding wheel pieces match the polished rod part of the tool rod; and the outer circular contours of adjacent grinding wheel pieces are connected and smoothly transitioned, and the overall contour after assembly is consistent with the groove of the tool body.

[0020] The utility model is further configured as follows: the tool rod is cylindrical as a whole, one end of which is provided with an external thread for screwing into the main shaft of the grinder; the other end is a polished rod with a flange end face, the flange end face is smooth and flat, and is used to closely support the grinding wheel; the polished rod portion is inserted into the main shaft of the grinder for transmitting torque.

[0021] The utility model is further configured as follows: the grinding wheel also includes a gasket, which is placed between the grinding wheel piece and the flange end surface of the tool rod and is used to adjust the installation angle of the grinding wheel piece.

[0022] The utility model is further configured as follows: the grinding wheel also includes a grinding wheel seat, which is composed of a spline shaft and a flange; the spline shaft cooperates with the spline hole of the grinding wheel to transmit torque; the flange is provided with bolt holes for fastening to the flange of the tool bar; the grinding wheel seat is also provided with a conical positioning surface, which cooperates with the conical hole of the flange of the tool bar to ensure that the two are coaxial;

[0023] The inner hole of the special-shaped grinding wheel is a spline hole, which is used to cooperate with the spline shaft of the grinding wheel seat;

[0024] The tool rod is provided with a conical positioning hole on the flange end surface to match the conical surface of the grinding wheel seat; a threaded hole is provided on the outer circle of the flange to fasten the grinding wheel seat with bolts.

[0025] The utility model is further configured as follows: the outer cylindrical surface of the tool rod is subjected to conductive treatment to serve as an electroforming substrate, and one end of the tool rod is threaded to be clamped on the main shaft of the grinder;

[0026] The grinding wheel is covered with a diamond abrasive layer, and the diamond abrasive layer is consistent with the spiral tooth groove profile of the broach.

[0027] Compared with the prior art, the utility model has the following advantages:

[0028] The utility model can obtain a special-shaped grinding wheel profile that is highly consistent with the spiral tooth groove profile of the broach by adopting the process means of cutting, assembling, and dressing of the waste grinding wheel. In particular, through the fine grinding of the grinding wheel and the actual tooth groove profile, the grinding wheel profile and the tooth groove profile can be perfectly matched, which greatly improves the profile accuracy of the tooth groove processing. In addition, the remaining abrasive layer of the waste grinding wheel is fully utilized, and the grinding geometric angle adapted to the tooth groove profile is regained through dressing and combination. Compared with a simple special-shaped grinding wheel, the grinding wheel profile of the utility model has undergone fine geometric optimization, and the cutting force and grinding heat are lower during the grinding process, and the grinding surface quality is better.

Brief Description of the Drawings

[0029] Figure 1 is a schematic structural diagram of the broach of this embodiment;

[0030] Figure 2 is a schematic diagram of the groove structure of this embodiment;

[0031] Figure 3 Schematic diagram of the structure of the grinding wheel of this embodiment;

[0032] Figure 4 is a schematic structural diagram of the screw of this embodiment;

[0033] Figure 5 Schematic diagram of the structure of the knife bar of this embodiment;

[0034] Figure 6 It is an assembly diagram of the integral special grinding wheel of this embodiment;

[0035] Figure 7 It is a schematic diagram of the complete assembly of the grinding wheel of this embodiment.

[0036] Reference numerals: tool body 1, grooves 2 and 3, grinding wheel 6, grinding wheel discs 4 and 5, screw 8, tool rod 9. [Specific implementation method]

[0037] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and is not to be construed as being limited to the embodiments described herein, but rather these embodiments are provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0038] It should be understood that the various steps described in the method implementation of the present utility model can be performed in different orders and / or performed in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present utility model is not limited in this respect.

[0039] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "connected" may be directly connected or indirectly connected through intermediate components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0040] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish between devices, modules or units, and are not used to limit these devices, modules or units to be different devices, modules or units, nor are they used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0041] In the present invention, the reason why the tooth groove processing is difficult to complete is mainly due to the following limitations:

[0042] Machine tool equipment limitations: Most of the helical grooves of broaches are special-shaped grooves, which require high flexibility and precision of the machine tool. The grinding wheel geometry of conventional grinders is relatively simple, and it is difficult to trim a special-shaped profile that matches the helical groove profile. In addition, when grinding the helical grooves, the grinding wheel needs to be fed synchronously with the broach, which requires high interpolation capability and rigidity of the machine tool.

[0043] Tool bar limitation: The tooth groove of the broach is generally long, and the diameter of the conventional grinding wheel is not large enough to cover the entire groove length. Large-diameter grinding wheels require large-sized tool bars, which increases the load on the machine tool spindle and reduces rigidity. In addition, when the grinding wheel is installed on the tool bar, the tool bar is required to have high coaxiality and dynamic balance performance, which puts higher requirements on the manufacturing and assembly accuracy of the tool bar.

[0044] Grinding wheel limitation: The profile of the spiral tooth groove of the broach is complex and diverse, including straight lines, arcs, curves and other geometric elements. It is difficult to trim a conventional standard grinding wheel to match the special-shaped contour. Even if a special-shaped grinding wheel is trimmed, its grinding geometry (such as effective grinding angle, cutting edge rake angle, etc.) is difficult to optimize, which affects the grinding performance and grinding wheel life.

[0045] Broach structure limitations: The tooth groove shape, size, helix angle and other parameters of different types of broaches vary greatly. During processing, it is necessary to replace the special-shaped grinding wheels of different specifications many times, which increases the time and economic costs. For some tooth grooves with particularly complex surfaces, it is difficult for conventional grinding wheels to trim the ideal contour, which affects the groove accuracy.

[0046] In addition to the above limitations, the processing of broach spiral tooth grooves also has the following technical difficulties:

[0047] The grinding wheel profile matches the tooth groove profile with high precision. Ideally, the grinding wheel profile should completely match the tooth groove profile, which requires strict control of the grinding wheel profile accuracy in multiple links such as repairing, assembly, installation, and grinding, which is very difficult in actual operation.

[0048] Wear dressing of grinding wheel profile. Grinding wheels will inevitably wear during the grinding process, and the profile will gradually lose its original geometric shape. How to accurately dress the grinding wheel profile after wear and restore its original shape is a major technical challenge. Conventional dressing methods are difficult to balance shape accuracy and grinding wheel performance.

[0049] Optimization of grinding wheel grinding parameters. When grinding spiral tooth grooves, the selection of parameters such as grinding wheel speed, feed speed, and cutting depth directly affects the groove accuracy and surface quality. However, the special-shaped grinding wheel and the broach present a complex multi-axis motion relationship, and the cutting geometry parameters are difficult to calculate and control. The grinding parameters are difficult to optimize and are mostly set based on experience.

[0050] Control of grinding force and grinding heat. The spiral tooth grooves of broaches are mostly deep and narrow, with a long grinding contact arc and a large cutting load per unit area of ​​the grinding wheel, which easily generates large cutting force and grinding heat. This will not only increase the wear of the grinding wheel, but also introduce grinding deformation and affect the groove accuracy. How to effectively control the grinding force and grinding heat is another technical difficulty.

[0051] In summary, due to the limitations of machine tools, tool bars, grinding wheels, and the structure of the broach itself, there are many difficulties in processing the complex spiral tooth grooves of broaches using conventional process methods. This requires starting from the design of grinding wheel structure, material selection, clamping method, dressing strategy, grinding parameter optimization, etc., to develop new special-shaped grinding wheels dedicated to the precision grinding of spiral tooth grooves and break through the bottleneck of existing processing technology.

[0052] In view of this, if Figure 1-7 As shown, the utility model discloses a broaching device, which is used to solve the above problems, and includes:

[0053] Blade 1, such as Figure 1 As shown, the blade body 1 has a plurality of grooves distributed longitudinally;

[0054] The plurality of grooves of the blade body 1 are special-shaped grooves, and the cross-sectional profiles of the plurality of grooves present multiple arcs or curves, and a convex portion is left between two adjacent grooves. The grooves on the blade body 1 have a certain helical angle and are distributed in a spiral shape around the central axis of the blade body 1. The blade body 1 has a first groove 2 and a second groove 3, such as Figure 2 As shown, the first groove 2 is in an arc shape at the bottom, with two sides connected by oblique straight lines and arcs, and the top is in an arc shape; the arc radius of the top of the second groove 3 is smaller than that of the first groove.

[0055] Specifically, the broach 1 is in the shape of an elongated column as a whole, and the cross section of the broach body is circular. A plurality of grooves 2 and 3 are evenly distributed in the longitudinal direction of the cylindrical broach body, and each groove is opened around the circumference of the broach body.

[0056] From the shape of slot 2 and slot 3, it is not a simple arc or rectangular slot, but a special-shaped slot. The cross-sectional profile of slot 2 and slot 3 presents multiple arcs or curves, which are composed of arcs and straight lines of different sizes. There is a convex part of a certain width between two adjacent slots, which plays the role of separation and support.

[0057] The processing of this special-shaped groove is relatively complicated, and ordinary grinding wheels are difficult to meet the requirements. Therefore, it is necessary to specially make special-shaped grinding wheels that complement the groove shape in order to grind out the broach tooth grooves that meet the requirements. Specifically, the cross-sectional shape of the grinding wheel must match the cross-sectional profile of the groove.

[0058] In addition, the grooves on the cutter body 1 have a certain helical angle and are distributed in a spiral shape around the central axis of the cutter body. This is to form a better chip discharge channel during broaching. The grinding wheel needs to be installed at a certain angle to ensure that the grinding wheel profile matches the spiral groove shape.

[0059] Figure 2The specific shape and size of the groove are shown. It can be seen that the shapes of grooves 2 and 3 are relatively special and complex. Among them, the outline of groove 2 is composed of multiple arcs and straight lines. The bottom is a circular arc with a larger radius, and the two sides are connected by oblique straight lines and arcs. The top is a circular arc with a smaller radius. The cross section of the entire groove is approximately trapezoidal, but the edges are rounded.

[0060] The structure of slot 3 is similar to slot 2, and is also composed of straight line segments and arcs, but the size and angle are different. Slot 3 is narrower overall, the radius of the top arc is smaller than that of slot 2, and the angle of the bevel is steeper.

[0061] The contour of this special-shaped groove needs to be strictly consistent with the outer contour of the grinding wheel to ensure the processing accuracy of the broach groove. The marking of angle and radius dimensions in the figure is also to guide the production of special grinding wheels.

[0062] In short, there are many different shapes and sizes of special-shaped grooves on the broach, which puts high demands on the processing technology and grinding wheel forming. It is necessary to solve technical problems such as the matching of the grinding wheel and the groove shape, and the matching of the grinding wheel cutting angle and the spiral groove shape to complete high-precision and high-quality tooth groove processing.

[0063] Several special-shaped grinding wheels (such as Figure 3 As shown, the grinding wheel 6 includes grinding wheel pieces 4 and 5), and the outer contours of the grinding wheel pieces 4 and 5 are consistent with the groove shape of the tool body 1;

[0064] Among them, the special-shaped grinding wheel pieces 4 and 5 are at least two pieces of waste grinding wheel pieces, the inner holes of the grinding wheel pieces 4 and 5 match the polished rod part of the tool rod; and the outer circular contours of adjacent grinding wheel pieces 4 and 5 are smoothly connected and transitioned. Figure 6 and 7 As is known, the overall outline after assembly is consistent with the groove of the blade body 1.

[0065] in, Figure 3 The waste grinding wheel used to make special grinding wheels is shown. It can be seen that this is a used grinding wheel, the outer circle is seriously worn and presents an irregular shape.

[0066] from Figure 6 It can be seen that the characteristics of special grinding wheels are:

[0067] The thickness of the grinding wheel is limited, and the spiral tooth groove on the broach generally extends to a certain length. This means that multiple grinding wheels need to be assembled together to cover the entire length of the tooth groove. Therefore, when assembling, it is necessary to pay attention to the smooth transition of the contours of each grinding wheel and the small gap between the splicing to ensure that a continuous and smooth spiral tooth groove profile is trimmed.

[0068] From the distance between the grinding wheel installation position and the flange of the tool bar, a gasket of a certain thickness is placed near the flange at the end of the tool bar. By selecting gaskets of different thicknesses, the inclination angle of the grinding wheel can be adjusted to match the rise angle of the broach helix. The angle adjustment is generally between 0-5°. To ensure that the grinding wheel profile fits the broach helix groove profile completely, it is often not enough to rely on a gasket of fixed thickness, and fine-tuning with a combination of gaskets is also required on site.

[0069] The outer circle profile of the grinding wheel in the figure can only roughly correspond to the rough groove of the broach. It is difficult to achieve precise matching with the various grooves of the actual broach by mechanical processing alone. The grinding wheel material has a certain elasticity and grindability, so the grinding wheel profile can be roughly processed first, then the broach and the grinding wheel are aligned, and then the grinding wheel is rotated to let it grind with the actual broach groove surface until the grinding wheel profile completely matches the groove. This "self-grinding" process can greatly improve the matching accuracy of the grinding wheel profile and the broach groove.

[0070] In addition, although the grinding wheel is cut and assembled from waste grinding wheels, its abrasive distribution and bonding agent performance are not uniform. Moreover, during the cutting and grinding process, the grinding wheel will generate high temperature locally, changing the cutting performance of the abrasive. Therefore, the clamped grinding wheel needs to be trimmed and corrected, including the flattening and trimming of the grinding wheel side, the sharpness trimming of the grinding surface, and the dynamic balance correction. In this way, the grinding wheel can run smoothly at high speed and the grinding performance is uniform.

[0071] During the use of special grinding wheels, the abrasive grains of the grinding wheel will gradually wear out and the cutting ability will decrease. However, the grinding wheel profile cannot be changed, otherwise the shape of the processed tooth groove will be deviated. Therefore, the grinding wheel should be regularly dressed, including the shedding and sharpness dressing of the abrasive grains, so as to restore the sharp cutting edge. During dressing, the grinding wheel profile must be strictly controlled and its special shape cannot be changed. Generally, diamond dressing rollers or diamond dressing pens can be used for special shape dressing.

[0072] The screw 8 passes through the inner holes of the grinding wheel pieces 4 and 5 to fasten the grinding wheel pieces 4 and 5 to the flange end surface of the tool rod 9;

[0073] Figure 4 What is shown is the screw 8 for assembling the special grinding wheel. This screw 8 plays the effect that the waste grinding wheel piece and the cutter bar 9 are connected and fixed.

[0074] from Figure 4 From the top, the screw 8 is a large flat head hexagon socket screw. The head of the screw 8 is a large and flat disc, which is convenient for applying pressure close to the side of the grinding wheel. There is a hexagon socket hole in the center of the head for tightening the screw 8 with a hexagonal wrench.

[0075] The rod of screw 8 is a smooth rod without threads. The rod diameter should be slightly smaller than the inner hole diameter of the grinding wheel so that the rod of screw 8 can pass through the inner hole of the grinding wheel.

[0076] The tail of the screw 8 is threaded and is used to be screwed into the threaded hole on the tool rod 9.

[0077] When using this screw 8 to assemble a special grinding wheel, the following technical factors should be considered:

[0078] The head of the screw 8 should be large enough to apply pressure evenly and press the grinding wheel tightly against the end face of the tool rod 9.

[0079] The diameter of the shank of screw 8 must match the inner hole diameter of the grinding wheel to play the role of positioning and transmitting torque.

[0080] The thread must match the internal thread of the 9-hole of the tool rod. It cannot loosen after tightening and must have sufficient screw-in depth to ensure a reliable connection.

[0081] The material of screw 8 must have sufficient strength, hardness and wear resistance to withstand the centrifugal force and vibration impact of the high-speed rotation of the grinding wheel.

[0082] During assembly, pay attention to the tightening torque of screw 8. It should not be too large to cause cracking of the grinding wheel, nor too small to cause loose connection.

[0083] The tool rod 9 is used for connecting, fixing and transmitting the main shaft torque.

[0084] Among them, the tool rod 9 is cylindrical as a whole, with an external thread at one end for screwing into the grinder spindle; the other end is a polished rod with a flange end face, and the flange end face is smooth and flat, which is used to tightly support the grinding wheels 4 and 5; the polished rod part is inserted into the grinder spindle for transmitting torque.

[0085] Figure 5 The tool bar 9 component of the special grinding wheel is shown. The tool bar 9 is an important part for mounting the grinding wheel on the grinding machine spindle.

[0086] As can be seen from the figure, the knife bar 9 is cylindrical in shape as a whole, with a flange at one end and a smooth rod at the other end. There is a section of thread at the rod portion near the flange.

[0087] The function of the flange of the tool bar 9 is to be close to the grinding wheel and provide a support surface. The grinding wheel is sleeved on the smooth rod part of the tool bar 9 and pressed against the flange end face by screws 8. In this way, the grinding wheel is firmly fixed on the tool bar 9 and rotates with the tool bar 9.

[0088] The polished rod part cooperates with the main shaft hole of the grinder to transmit the torque of the main shaft and drive the tool bar 9 and the grinding wheel to rotate. The tolerance grade of the polished rod part is relatively high, and the size and roundness must ensure precise cooperation with the main shaft hole to reduce radial runout.

[0089] The external thread on the tool bar 9 is used to be screwed into the internal thread hole at the end of the grinding machine spindle. The tool bar 9 is fixed to the spindle through the threaded connection. The tightened threaded connection must ensure rigidity without loosening and be easy to load and unload.

[0090] The cutter bar 9 also plays a role in adjusting the installation angle of the grinding wheel within a certain range. By placing a gasket of a certain thickness between the flange end face and the grinding wheel, the inclination angle of the grinding wheel can be adjusted to match the rise angle of the spiral tooth groove.

[0091] For the shank 9, the following technical requirements are mainly considered:

[0092] 1. The material of the shank 9 must have sufficient strength, rigidity and wear resistance, and generally uses high-quality alloy steel.

[0093] 2. The size and coaxiality of the flange and the polished rod must be controlled at a very high precision level to reduce installation errors.

[0094] 3. The thread must match the spindle hole thread standard, and the thread surface and pitch accuracy must be high to facilitate installation and disassembly.

[0095] 4. The surface of the shank 9 needs to be subjected to surface heat treatment such as carburizing quenching or nitriding to improve hardness and wear resistance.

[0096] 5. During assembly, pay attention to the thread tightening torque and the selection of gaskets to avoid grinding vibration and grinding wheel installation angle error.

[0097] In addition, the grinding wheel also includes a gasket (not shown in the figure), which is placed between the grinding wheel pieces 4 and 5 and the flange end surface of the tool rod 9 to adjust the installation angle of the grinding wheel pieces 4 and 5.

[0098] Figure 7 It is a schematic diagram of the assembly structure of a special grinding wheel, which more clearly shows how the grinding wheel, screws, gaskets, tool rods and other components are assembled together.

[0099] As can be seen from the figure, the two grinding wheels 4 and 5 are connected to the flange end face of the tool bar 9 by screws 8. The screws 8 pass through the through holes of the grinding wheel and are screwed into the internal threaded holes on the flange end face of the tool bar 9 to tighten and fix the grinding wheel.

[0100] A gasket of a certain thickness is placed between the grinding wheel 4, 5 and the flange end face of the tool bar. By selecting gaskets of different thicknesses, the installation inclination angle of the grinding wheel 4, 5 can be adjusted to match the rise angle of the helical tooth groove of the broach.

[0101] The other end of the tool bar 9 with thread is screwed into the internal thread hole of the grinder spindle. Through the threaded connection, the entire special grinding wheel is fixed on the grinder. The tool bar also plays the role of transmitting the spindle torque and driving the grinding wheel to rotate.

[0102] The assembled special grinding wheel rotates the main shaft, and the grinding wheel with special profile rotates at high speed and moves to the position of the spiral tooth groove of the broach, so that the tooth groove can be ground. During the grinding process, the grinding wheel profile must be strictly kept consistent with the tooth groove profile to obtain the ideal tooth groove shape accuracy.

[0103] In addition, the shim between the grinding wheel and the tool bar plays a role in adjusting the angle. However, in actual assembly, due to certain geometric errors between the grinding wheel and the spiral tooth groove of the broach, it is difficult to achieve precise angle matching through a shim of fixed thickness. Therefore, in actual processing, it is often necessary to stack multiple thin shims, check the fit between the grinding wheel and the actual tooth groove while clamping, and then fine-tune the shim thickness until the two are completely consistent. This assembly process requires a high level of assembly technology.

[0104] The matching surface of the grinding wheel and the tool bar flange has relatively high requirements. If there is a gap or non-parallelism between the two, vibration and deflection will occur during high-speed rotation, affecting the processing accuracy. Therefore, the end face of the tool bar flange must be fine-machined to ensure its flatness and verticality. The plane that the grinding wheel matches with it must also be trimmed for flatness and parallelism. During assembly, special tools must be used to press the grinding wheel and the tool bar flange to ensure that the matching surfaces of the two are tightly fitted and cannot be loose.

[0105] Although the screws play a role in connection and fixing, if the distance between the screw head and the outer edge of the grinding wheel is too small, it will interfere during the grinding process. Therefore, the size of the screw head and the inner hole diameter of the grinding wheel should be reasonably selected to reserve enough clearance. When tightening the screws, apply force evenly to avoid local stress concentration that may cause the grinding wheel to crack.

[0106] The figure shows only two assembled grinding wheels, but when machining longer spiral tooth grooves, three or more grinding wheels may be required. It is important to ensure that the contours of adjacent grinding wheels are smoothly connected to avoid leaving steps or marks on the tooth grooves. At the same time, ensure the coaxiality of each grinding wheel in the axial and radial directions to avoid radial movement or axial swing during rotation.

[0107] After the whole special grinding wheel is assembled, dynamic balancing correction should be performed on the grinding machine. This is because factors such as grinding wheel assembly and screw connection introduce imbalance. If the balance correction is not performed, it will produce violent vibrations during high-speed rotation, which will not only affect the processing accuracy, but also easily damage the grinding machine bearings. Dynamic balancing correction can be performed by opening balancing holes on the grinding wheel, sticking balancing blocks, etc.

[0108] In addition, in another embodiment, a special grinding wheel of a detachable special-shaped grinding wheel assembly can be used. That is, the grinding wheel is not directly fixed on the tool bar, but is first clamped on a detachable grinding wheel seat (not shown in the figure), and then the grinding wheel seat is installed on the tool bar flange. The specific structure is as follows:

[0109] The grinding wheel also includes grinding wheel discs 4 and 5 seats, which are composed of a spline shaft and a flange; the spline shaft cooperates with the spline holes of the grinding wheel discs 4 and 5 to transmit torque; the flange is provided with bolt holes for fastening to the flange of the tool bar 9; the grinding wheel discs 4 and 5 seats are also provided with a conical positioning surface, which cooperates with the conical hole of the flange of the tool bar 9 to ensure that the two are coaxial;

[0110] The inner holes of the special-shaped grinding wheels 4 and 5 are spline holes, which are used to cooperate with the spline shafts of the grinding wheels 4 and 5;

[0111] The tool rod 9 has a conical positioning hole on the flange end surface to match the conical surfaces of the grinding wheel pieces 4 and 5; and a threaded hole is provided on the outer circle of the flange to fasten the grinding wheel pieces 4 and 5 by bolts.

[0112] After the detachable grinding wheel seat, the advantages of the embodiment of the utility model are:

[0113] The grinding wheel is separated from the tool bar, which is easy to disassemble and assemble. When the grinding wheel is worn or needs to be changed, only the grinding wheel assembly needs to be replaced without reinstalling the tool bar. The grinding wheel seat can be designed as a standard part corresponding to different types of grinding wheels. A set of grinding wheel seats can match a variety of grinding wheels, which improves versatility. The grinding wheel seat and the tool bar are positioned with a conical surface, with high coaxiality and uniform torque transmission. Bolts are used for fastening, and the connection is reliable. The grinding wheel and the grinding wheel seat are splined, with coaxial centering, uniform torque transmission, and easy and quick replacement.

[0114] In another embodiment, a special grinding wheel of integral electroformed diamond shaped grinding wheel can be used. That is, the grinding wheel is not mechanically assembled, but electroformed by electroforming process to electroform a diamond abrasive layer that matches the tooth groove profile of the broach on the entire surface of the shank. The specific structure is as follows:

[0115] The outer cylindrical surface of the tool rod 9 is subjected to conductive treatment to serve as an electroforming substrate, and one end of the tool rod 9 is threaded for clamping on the main shaft of the grinder;

[0116] The grinding wheel is covered with a diamond abrasive layer, and the diamond abrasive layer is consistent with the spiral tooth groove profile of the broach. Among them, the electroformed diamond abrasive layer adopts an electroforming process to deposit a diamond abrasive layer that is consistent with the spiral tooth groove profile of the broach on the surface of the tool bar. The thickness of the electroformed layer is generally 1-3mm, the diamond particle size is 100-120 mesh, and the distribution is uniform and dense.

[0117] Its advantages are:

[0118] The electroformed diamond abrasive layer is integrated with the tool bar without mechanical connection, and there are no problems with the grinding wheel installation accuracy and connection strength.

[0119] Diamond abrasives have high hardness, high sharpness, strong grinding ability, good wear resistance, and can greatly increase the service life of the grinding wheel.

[0120] The thickness of the electroformed layer is small and the overall diameter of the grinding wheel is small, which is conducive to processing smaller broaches.

[0121] The electroforming process can achieve high-precision replication of the grinding wheel profile, high grinding wheel profile accuracy, and better consistency of the spiral tooth groove during grinding.

[0122] The electroformed diamond abrasive layer has high bonding strength with the surface of the tool bar, is not easy to fall off, and has good safety.

[0123] The entire electrocasting grinding wheel is light in weight and has a small rotational inertia, which is conducive to high-speed grinding and improves processing efficiency.

[0124] The special shaped grinding wheel proposed in the utility model can effectively solve the technical problems existing in the processing of the spiral tooth groove of the broach through multiple key designs and process measures. The specific technical effects are reflected in the following aspects:

[0125] Improve the matching accuracy between the grinding wheel profile and the tooth groove profile. By using the cutting, assembly, and dressing of waste grinding wheel pieces, a special-shaped grinding wheel profile that is highly consistent with the broach spiral tooth groove profile can be obtained. In particular, through the fine grinding of the grinding wheel piece and the actual tooth groove profile, the grinding wheel profile and the tooth groove profile can be perfectly matched, greatly improving the profile accuracy of the tooth groove processing.

[0126] The effective grinding range of the grinding wheel is expanded. Conventional standard grinding wheels have limited diameters and are difficult to cover long spiral tooth grooves. However, the utility model can obtain an expanded grinding wheel profile that matches the entire tooth groove length by assembling multiple special-shaped grinding wheel pieces. The expansion of the effective grinding range of the grinding wheel reduces the problem of frequent tool changes or multiple segmented processing due to insufficient grinding wheel width, thereby improving processing efficiency.

[0127] The cutting performance and service life of the grinding wheel are improved. The utility model makes full use of the remaining abrasive layer of the waste grinding wheel, and regains the grinding geometric angle adapted to the tooth groove profile through dressing and combination. Compared with simple special-shaped grinding wheels, the grinding wheel profile of the utility model has undergone fine geometric optimization, and the cutting force and grinding heat are lower during the grinding process, and the grinding surface quality is better. In addition, due to the use of standardized tool bars and screw connectors, when the grinding wheel is worn, only the grinding wheel needs to be replaced without reinstalling the tool bar, which greatly saves auxiliary time and extends the total service life of the grinding wheel.

[0128] The difficulty of grinding wheel installation and dynamic balancing is reduced. Conventional integral special-shaped grinding wheels have large mass and inertia, are inconvenient to install, and are difficult to balance. The utility model adopts split grinding wheel pieces for assembly. Each grinding wheel piece has a small inertia and is fastened to the rigid tool bar by screws. While ensuring sufficient strength and rigidity, the difficulty of grinding wheel installation and dynamic balancing is greatly reduced. By selecting dynamic balancing gaskets and optimizing the tightening torque of screws, the grinding wheel can have higher dynamic balancing accuracy when rotating at high speed.

[0129] The versatility and interchangeability of the grinding wheel are improved. The utility model adopts standardized special-shaped grinding wheel pieces and tool bar connectors, and grinding wheel pieces of different models can be matched and installed on the same tool bar through screws and gaskets. When different tooth groove profiles need to be processed, only the corresponding type of grinding wheel piece needs to be replaced without replacing the entire grinding wheel assembly. The versatility of the grinding wheel is greatly improved and the use cost is reduced.

[0130] The functional requirements for CNC grinding machines are reduced. Conventional special-shaped grinding wheels process complex spiral tooth grooves, which places high demands on the multi-axis linkage, interpolation algorithm and other performance of CNC grinding machines. However, the utility model realizes the integral forming grinding of complex surfaces through the precisely matched special-shaped grinding wheel profile, simplifies the grinding motion, and reduces the functional requirements for the grinding machine. General CNC grinding machines can be installed with the special grinding wheel of the utility model through simple modification, thereby realizing high-precision grinding of broach spiral tooth grooves.

[0131] In summary, the utility model systematically solves the key technical problems in the grinding of broach spiral tooth grooves from the aspects of grinding wheel structure design, manufacturing process, clamping connection, use and maintenance. Compared with the prior art, the utility model has the advantages of high tooth groove processing precision, high efficiency, long grinding wheel service life, good versatility, etc., which can meet the actual needs of high-precision, high-efficiency and low-cost processing of broach spiral tooth grooves, and has a good prospect for promotion and application.

[0132] Some exemplary embodiments of the utility model are described above, but those skilled in the art will appreciate that changes may be made to these exemplary embodiments without departing from the principles or spirit of the utility model, and the scope of the utility model is defined by the claims and their equivalents.

Claims

1. A broaching device, characterized in that: include: A knife body, wherein the knife body has a plurality of grooves distributed longitudinally; A plurality of special-shaped grinding wheels, the outer contour of which matches the groove of the cutter body; A screw passes through the inner hole of the grinding wheel to fasten the grinding wheel to the flange end surface of the tool rod; The tool rod is used for connecting, fixing and transmitting the main shaft torque.

2. The broaching device according to claim 1, characterized in that: The plurality of grooves of the blade body are special-shaped grooves, the cross-sectional profiles of the plurality of grooves present multiple arcs or curves, and a convex portion is left between two adjacent grooves.

3. The broaching device according to claim 2, characterized in that: The grooves on the cutter body have a certain helix angle and are distributed in a spiral shape around the central axis of the cutter body.

4. The broaching device according to claim 1, characterized in that: The blade body comprises a first groove and a second groove. The first groove is in an arc shape at the bottom, with two sides connected by oblique straight lines and an arc, and the top is in an arc shape. The arc radius of the top of the second groove is smaller than that of the first groove.

5. The broaching device according to claim 1, characterized in that: The special-shaped grinding wheel pieces are at least two pieces of waste grinding wheel pieces, the inner holes of the grinding wheel pieces match the polished rod part of the tool rod; and the outer circular contours of adjacent grinding wheel pieces are smoothly connected and transitioned, and the overall contour after assembly is consistent with the groove of the tool body.

6. The broaching device according to claim 1, characterized in that: The tool rod is cylindrical as a whole, with one end having an external thread for screwing into the grinder spindle; the other end is a polished rod with a flange end face, the flange end face is smooth and flat, and is used to closely support the grinding wheel; the polished rod portion is inserted into the grinder spindle for transmitting torque.

7. The broaching device according to claim 1, characterized in that: The grinding wheel also includes a gasket, which is placed between the grinding wheel and the flange end face of the tool rod and is used to adjust the installation angle of the grinding wheel.

8. The broaching device according to claim 1, characterized in that: The grinding wheel also includes a grinding wheel seat, which is composed of a spline shaft and a flange; the spline shaft cooperates with the spline hole of the grinding wheel to transmit torque; the flange is provided with bolt holes for fastening to the flange of the tool bar; the grinding wheel seat is also provided with a conical positioning surface, which cooperates with the conical hole of the flange of the tool bar to ensure that the two are coaxial; The inner hole of the special-shaped grinding wheel is a spline hole, which is used to cooperate with the spline shaft of the grinding wheel seat; The tool rod is provided with a conical positioning hole on the flange end surface to match the conical surface of the grinding wheel seat; a threaded hole is provided on the outer circle of the flange to fasten the grinding wheel seat with bolts.

9. The broaching device according to claim 1, characterized in that: The outer cylindrical surface of the tool rod is subjected to conductive treatment to serve as an electroforming substrate, and one end of the tool rod is threaded for clamping on the main shaft of the grinder; The grinding wheel is covered with a diamond abrasive layer, and the diamond abrasive layer is consistent with the spiral tooth groove profile of the broach.

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