A tooling fixture for an automobile transmission gear

Abstract

The present application relates to the technical fields of gear fixture, in particular to a kind of tooling fixture of automobile gearbox gear, the positioning assembly of being coupled with each other by self-locking and changing own position is installed in V belt assembly, the damping assembly is installed in the positioning assembly, the function of the damping assembly is to change the relative position of positioning assembly, in turn change workpiece clamping mode;The present application solves the problem of how to realize the protection of fixture in the machining process of automobile gearbox gear.

Description

A tooling fixture for automotive transmission gears Technical Field

[0001] This invention relates to the field of gear fixture technology, specifically a tooling fixture for automotive transmission gears. Background Technology

[0002] Automotive transmission gears are crucial components used to transmit power and change the rotational speed of the vehicle's drive shaft. By selecting different gear combinations, vehicles can achieve ideal power output and fuel efficiency under various driving conditions. Tooling fixtures for automotive transmission gears are tools used to fix and manipulate these gears. To ensure the temperature and reliability of gear machining, automotive transmission gear tooling fixtures are characterized by high strength, high wear resistance, and high precision. The design of automotive transmission gear tooling fixtures is customized according to specific gear design and manufacturing requirements.

[0003] In the actual gear machining process, most existing fixtures are three-jaw fixtures. The gear jaws fix the gear and perform cutting, milling and grinding processes on the gear. In order to reduce the damage to the fixture and tool during the machining process, the tooling fixtures for automotive gearbox gears need to adjust and optimize the clamping position and clamping force of the gear. Inaccurate clamping position and insufficient clamping force will lead to a decrease in machining accuracy and a reduction in the service life of the fixture.

[0004] However, during the use of fixtures, due to various factors such as improper operation by workers and deviations in the production process of cutting tools and fixtures, localized stress on the fixtures can lead to wear. At this time, the wear is small and difficult to detect. Workers continue to use the fixtures in the original way, resulting in further damage and reduced service life. At the same time, during the machining process, the cutting tool collides with the gears to complete cutting, milling and grinding processes. The force generated during the collision is transmitted to the fixture by the gears, which in turn damages the fixture and reduces its service life.

[0005] In view of this, some solutions have been proposed in the prior art: positioning the gear pitch circle by ball head pins and clamping the ball head pins by rotating a disc with helical grooves, thereby positioning the gear and ensuring the stability of gear positioning. This solves the problem of fixture wear caused by inaccurate workpiece positioning. However, it fails to solve the problem of tool damage to the fixture during gear machining. At the same time, in the machining process of automotive gearbox gears, precision machining is required using equipment such as gear hobbing machines and gear grinding machines. At this time, using ball head pins for positioning will lead to excessive local stress at the keyway of the gear tooth surface, resulting in a decrease in assembly accuracy and a reduction in the service life of the gearbox.

[0006] To address the aforementioned issues, a tooling fixture for automotive gearbox gears is designed. Summary of the Invention

[0007] This invention provides a tooling fixture for automotive transmission gears, which clamps the gears by mutual coupling and self-locking and changing its own position, thereby positioning and clamping the gears and solving the problem of how to protect the fixture during the processing of automotive transmission gears.

[0008] The technical solution of this invention is as follows: a tooling fixture for automotive gearbox gears, comprising a V-belt assembly and a motor driving the V-belt assembly. During the machining of automotive gearbox gears, it is necessary to avoid excessive impact and damage to the transmission system and power source during startup, and to reduce noise and vibration during cutting, thereby preventing damage to the fixture during transmission. Therefore, a V-belt is selected as the main transmission device. The V-belt assembly includes a base, a bracket, a drive shaft, a drive pulley, a V-belt, a driven pulley, a positioning assembly, and a shock-absorbing assembly. The V-belt assembly is equipped with a positioning assembly that self-locks and changes its own position through mutual coupling. The positioning assembly itself clamps the workpiece through mutual coupling and self-locking between a lead screw and a ratchet mechanism. The function of the shock-absorbing assembly is to change the relative position of the positioning assembly, thereby changing the workpiece clamping method.

[0009] In the machining process of automotive gearbox gears, the motor first drives the positioning component to rotate forward via the V-belt assembly, changing the relative position of the positioning component. At this time, the gear blank to be machined is placed near the positioning component. During the operation of the positioning component, the working mode of the shock absorption component is first selected according to the size of the workpiece and the machining position. Then, the shock absorption component clamps the workpiece. At this time, the motor reverses, and the positioning component achieves mutual coupling and self-locking, thereby realizing automatic centering of the gear and ensuring the stability of the fixture during the clamping process. Finally, the tool approaches the workpiece, and the force generated when the tool contacts the workpiece is buffered by the shock absorption component and then transmitted to the fixture, thereby achieving the effect of protecting the shock absorption component.

[0010] Preferably, the positioning assembly includes a ratchet ring, an inner ring, a support rod, a pawl, a lead screw, a sliding block, and a retaining ring. The driven wheel is connected to the ratchet ring, thereby achieving workpiece positioning and restricting four degrees of freedom (translation and rotation) perpendicular to the ratchet ring axis, preventing the automotive gearbox gear from shifting. The inner ring is fixedly connected inside the ratchet ring. The function of the inner ring is to change the magnitude and direction of the torque on the ratchet ring by rotating it forward and backward. When the ratchet ring rotates forward, the inner ring rotates with the ratchet ring, thereby changing the position of the sliding block through the lead screw and clamping the automotive gearbox gear. When the ratchet ring rotates backward, the automotive gearbox gear begins to be processed. At this time, the inner ring does not rotate, and therefore the lead screw does not rotate, ensuring that the sliding block does not move, restricting the translational degree of freedom of the automotive gearbox gear along its own axis, thereby ensuring clamping stability. The axial section of the inner ring is an I-shaped surface. The I-shaped surface away from the centroid end resists bending by increasing the moment of inertia, and the I-shaped surface near the centroid end resists shear. A support rod is fixedly connected to the inner ring, and a pawl is rotatably connected to the support rod. The pawl is located at the end of the inner ring away from the centroid. During the machining of the automotive gearbox gear, the pawl continuously slides relative to the ratchet ring, thereby generating a bending moment on the inner ring and the support rod, causing bending deformation of the inner ring and the support rod. During the machining process, the inner ring needs to continuously provide clamping force to the automotive gearbox gear, and the automotive gearbox gear reacts to the inner ring, causing shear deformation of the inner ring. At this time, the I-shaped surface can effectively resist bending at the support rod and the pawl, and resist shear at the center of the inner ring, preventing deformation.

[0011] The pawl has a limiting groove, and the ratchet ring has mounting rings. The mounting rings prevent the pawl from shifting axially along the support rod. They are spaced apart along the ratchet ring. During initial installation of the support rod and pawl, the mounting rings provide positioning, facilitating installation. When the positioning assembly is not in operation, to prevent wear caused by prolonged engagement between the pawl and the ratchet ring, and to prevent damage to the ratchet ring due to localized stress, the limiting groove on the pawl engages with the mounting ring to press the pawl away from the ratchet ring. When needed, the mounting rings are removed, and the pawl automatically engages with the ratchet ring for normal operation. Simultaneously, the limiting groove provides a notch at the engagement point between the pawl and the ratchet ring, increasing the flow range of lubricating oil without affecting the operation of the ratchet ring, thus preventing excessive localized wear between the pawl and the ratchet ring. The mounting rings are spaced apart along the ratchet ring for easy disassembly.

[0012] A lead screw is fixedly connected to one end of the ratchet ring. The function of the lead screw is to lock the axial rotational freedom of the inner ring through mutual coupling. When the motor reverses, it only drives the ratchet ring to rotate, while the inner ring does not rotate, thus locking the lead screw. At the same time, since the moving block cannot drive the lead screw to rotate, the lead screw locks the inner ring. Therefore, the lead screw and the inner ring form a mutual coupling self-locking. The cross-section of the lead screw is an isosceles trapezoid, which balances the load on both ends of the sliding block. The lead screw clamps the automotive gearbox gear under the load from the sliding block. The thread helix angle of the lead screw is smaller than the static friction angle, which prevents the sliding block from driving the lead screw to rotate, ensuring the stability of the shock absorption assembly clamping the automotive gearbox gear and improving the load capacity. The thread helix angle of the lead screw is larger than the inverse cosine angle between the hypotenuse and the base of the isosceles trapezoid, which reduces the time required for the clamping process and increases the displacement of the moving block relative to the lead screw after one rotation. A sliding block is slidably connected to the lead screw to prevent it from reversing. During the machining of automotive gearbox gears, the position of the damping component relative to the gearbox remains unchanged, thus restricting the sliding block from moving. This prevents the sliding block from driving the lead screw to rotate if the self-locking effect between the sliding block and the lead screw fails. A retaining ring is fixedly connected to one end of the sliding block. The retaining ring clamps the workpiece by bearing the pressure of the damping component. The relative position of the retaining ring and the moving block does not change. At the same time, since the moving block cannot drive the lead screw, it bears the stress generated by the damping component. At this time, this part of the stress is transmitted to the fixture through the retaining ring, clamping the automotive gearbox gear by restricting the degree of freedom of translation in the axial direction of the gearbox.

[0013] When initially installing or replacing the ratchet ring, first mate the mounting ring with the limiting groove on the pawl, then install the pawl on the support rod, and finally mate the inner ring with the ratchet ring to complete the installation or replacement. Before machining the automotive gearbox gears, the motor rotates forward, and the motor's power is transmitted to the ratchet ring via the V-belt. The ratchet ring rotates forward around the support rod axis, and the ratchet ring drives the inner ring to rotate via the pawl. The inner ring drives the lead screw to rotate, and the lead screw drives the moving block to slide, thereby clamping the automotive gearbox gears. During the machining of the automotive gearbox gears, the motor reverses, and the motor drives the ratchet ring to rotate in reverse via the V-belt assembly. At this time, the pawl moves along... The ratchet ring slides while the inner ring does not rotate. Since the inner ring is fixedly connected to the lead screw, the lead screw does not rotate, and the sliding block cannot drive the lead screw to rotate. This ensures that the lead screw cannot drive the inner ring to rotate. Therefore, the inner ring and the lead screw achieve mutual coupling and self-locking, ensuring the stability of the automotive gearbox gear clamping. Before the tool contacts the workpiece, the tool first contacts the damping component. The stress on the damping component is transferred to the retaining ring. Since the retaining ring is fixedly connected to the sliding block, the sliding block is locked by the lead screw and cannot move. This allows the lead screw, sliding block, and retaining ring to jointly bear the load transmitted by the damping component, thereby preventing wear or local damage to the positioning component.

[0014] Preferably, the shock-absorbing assembly includes a gear gripper, a connecting shaft, a transmission gear, a gear ring, a spring, a limiting shaft, a fixing plate, a limiting hole, a connecting plate, a straight slot, and a slide rod. The lower end of the gear gripper is fixedly connected to the connecting shaft, which in turn is fixedly connected to the transmission gear. A retaining ring is fixedly connected to the gear ring, and the transmission gear meshes with the gear ring. The clockwise and counterclockwise rotation directions of the gear ring provide two clamping methods for automotive transmission gears of different sizes and processing positions. For smaller automotive transmission gears or gears requiring enlarged holes, the gear ring rotates clockwise, causing the gripper to retract inwards, with the clamping position at the gear's tooth tip circle. For larger automotive transmission gears or gears requiring shaving or grinding, the gear ring rotates counterclockwise, causing the gripper to retract inwards, with the clamping position at the gear's tooth tip circle. Expanding outwards, the gripper's clamping position is located at the axis of the automotive gearbox gear, achieving flexible clamping of gears of different sizes and processing requirements. A spring is fixedly connected to one side of the sliding block, and a limit shaft is fixedly connected to the end of the spring away from the sliding block. A fixed plate is slidably connected to the limit shaft near the spring section journal, and the fixed plate has a limit hole. A connecting plate is fixedly connected to the limit shaft away from the spring section journal, and the connecting plate has a straight slot that provides freedom of movement for the connecting plate. The fixed plate is rotatably connected to a sliding rod that supports the gear gripper by changing its angle relative to the limit shaft. The sliding rod swings around the hinge point between the sliding rod and the fixed plate, thereby driving the connecting plate to translate. The relative movement between the connecting plate and the sliding rod cancels out some vibration, thus protecting the gripper. The connecting plate is "human" shaped, and its three endpoints are labeled a, b, and c clockwise, with the straight slot located at points a, b, and c. The "human"-shaped structure of the connecting plate allows the three ends to support each other, improving the stability and load-bearing capacity of the connecting plate. The bottom end of the slide bar is connected to a protrusion, which is fan-shaped to buffer the impact of the tool. When the tool contacts the slide bar, it first contacts the protrusion and slides along the edge of the fan-shaped protrusion, further delaying the contact time between the tool and the gearbox gear, preventing the tool from directly contacting the slide bar and causing the slide bar to fully bear the stress of the tool.

[0015] Preferably, the gear grippers are hook-shaped to accommodate different workpiece sizes, thus allowing for different clamping methods for gears of different sizes and processing requirements in conjunction with the clockwise and counterclockwise rotation of the gear ring. The larger portion of the arc formed by the hook shape is the outer side, and the smaller portion is the inner side. The outer part of the hook shape contacts and locks with the ring at the axis of the automotive transmission gear, while the inner side of the hook shape contacts and locks with the tip circle of the automotive transmission gear. The arc-shaped surface provides better contact with the automotive transmission gear. There are three gear grippers, and the centers of gravity of the three gear grippers form an equilateral triangle. The automotive transmission gear is clamped using three fulcrums evenly arranged relative to the axis of the automotive transmission gear, resulting in more stable stress bearing.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. A tooling fixture for automotive transmission gears according to the present invention, the device clamps the automotive transmission gears by mutual coupling and self-locking and changing its own position, and then uses the self-locking effect generated by the movement of the positioning component to automatically center the automotive transmission gears while restricting the degrees of freedom of the automotive transmission gears, thereby accurately positioning the automotive transmission gears and avoiding damage to the fixture caused by improper operation.

[0018] 2. A tooling fixture for automotive gearbox gears according to the present invention, the device provides bidirectional protection against variable load impact, and utilizes the cooperation of positioning components and shock-absorbing components to achieve joint bearing of multiple components on the variable load transmitted by the shock-absorbing components, and utilizes bidirectional locking positioning components to protect the shock-absorbing components.

[0019] 3. A tooling fixture for automotive gearbox gears according to the present invention, the device changes the position of the connecting plate through simple harmonic motion, and then uses the relative movement of multiple sliding rods and the connecting plate to synchronously share the pressure on the shock absorption assembly, thereby improving the load-bearing capacity of the shock absorption assembly itself. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort:

[0021] Figure 1 is a schematic diagram of the overall appearance of the present invention;

[0022] Figure 2 is a left view of the positioning component and the shock absorption component of the present invention;

[0023] Figure 3 is a cross-sectional view of the AA section of the present invention;

[0024] Figure 4 is an enlarged view of section B in Figure 2 of this invention;

[0025] Figure 5 is a top view of the positioning component and the shock absorption component of the present invention;

[0026] Figure 6 is a cross-sectional view of the CC section of the present invention;

[0027] Figure 7 is a diagram illustrating the inner ring-shaped surface of the present invention;

[0028] Figure 8 is a front view of some of the shock absorption components of the present invention;

[0029] In the diagram: 1. V-belt assembly; 11. Base; 12. Bracket; 13. Drive shaft; 14. Drive wheel; 15. V-belt; 16. Driven wheel; 2. Motor; 3. Positioning assembly; 31. Ratchet ring; 311. Mounting ring; 32. Inner ring; 321. Support rod; 322. I-shaped surface; 33. Pawl; 331. Limiting groove; 34. Lead screw; 35. Sliding block; 36. Retaining ring; 4. Shock absorption assembly; 41. Gear gripper; 42. Connecting shaft; 43. Transmission gear; 44. Gear ring; 45. Spring; 46. Limiting shaft; 47. Fixing plate; 471. Limiting hole; 48. Connecting plate; 481. Straight groove; 49. Slide rod; 491. Protrusion. Detailed Implementation

[0030] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0031] As shown in Figure 1, a tooling fixture for automotive gearbox gears includes a V-belt assembly 1 and a motor 2 driving the V-belt assembly 1. During the machining of automotive gearbox gears, it is necessary to avoid excessive impact and damage to the transmission system and power source during startup, and to reduce noise and vibration during cutting, thereby preventing damage to the fixture during transmission. Therefore, a V-belt is selected as the main transmission device. The V-belt assembly 1 includes a base 11, a bracket 12, a drive shaft 13, a drive pulley 14, a V-belt 15, a driven pulley 16, a positioning assembly 3, and a shock-absorbing assembly 4. The V-belt assembly 1 is equipped with a positioning assembly 3 that changes its own position through mutual coupling and self-locking. The positioning assembly 3 clamps the workpiece through mutual coupling and self-locking of a lead screw and a ratchet mechanism. The positioning assembly 3 is equipped with a shock-absorbing assembly 4, which changes the relative position of the positioning assembly 3, thereby changing the workpiece clamping method.

[0032] In the machining process of automotive gearbox gears, motor 2 first drives positioning component 3 to rotate forward via V-belt assembly 1, changing the relative position of positioning component 3. At this time, the gear blank to be machined is placed near positioning component 3. During the operation of positioning component 3, the working mode of shock absorber 4 is first selected according to the size of the workpiece and the machining position. Then, shock absorber 4 clamps the workpiece. At this time, motor 2 reverses, and positioning component 3 achieves mutual coupling and self-locking, thereby realizing automatic centering of the gear and ensuring the stability of the clamping process. Finally, the tool approaches the workpiece, and the force generated when the tool contacts the workpiece is buffered by shock absorber 4 and then transmitted to the clamp, thereby achieving the effect of protecting shock absorber 4.

[0033] As shown in Figures 1 to 7, the driven wheel 16 is connected to a ratchet ring 31, thereby positioning the workpiece and restricting four degrees of freedom (translation and rotation) in two directions perpendicular to the axis of the ratchet ring 31, preventing the gearbox gear from shifting. An inner ring 32 is fixedly connected inside the ratchet ring 31. The function of the inner ring 32 is to change the magnitude and direction of the torque on the ratchet ring 31 by rotating it forward and backward. When the ratchet ring 31 rotates forward, the inner ring 32 rotates with it, thereby changing the position of the sliding block 35 via the lead screw 34 and clamping the gearbox gear. When the ratchet ring 31 rotates backward, it begins to engage the gearbox gear. During gear machining, the inner ring 32 does not rotate, and consequently the lead screw 34 does not rotate, ensuring that the sliding block 35 does not move. This restricts the translational freedom of the automotive gearbox gear along its own axis, thereby ensuring clamping stability. The axial section of the inner ring is an I-shaped surface 322. The I-shaped surface 322 resists bending by increasing the moment of inertia at the fixed connection between the inner ring 32 and the support rod 321, and resists shear at the center of the inner ring 32. Because the I-shaped surface 322 has the characteristics of resisting bending by increasing the moment of inertia away from the centroid and resisting shear by being close to the centroid, the I-shaped surface 322 can effectively prevent the inner ring 32 from deforming. A support rod 321 is fixedly connected to the inner ring 32, and a pawl 33 is rotatably connected to the support rod 321. The pawl 33 is located at the end of the inner ring 32 away from the centroid. During the machining of the automotive gearbox gear, the pawl 33 continuously slides relative to the ratchet ring 31, thereby generating a bending moment on the inner ring 32 and the support rod 321, causing bending deformation of the inner ring 32 and the support rod 321. During the machining process, the inner ring 32 needs to continuously provide clamping force to the automotive gearbox gear, and the automotive gearbox gear reacts to the inner ring 32, causing shear deformation of the inner ring 32. At this time, the I-shaped surface 322 can effectively resist bending at the support rod 321 and the pawl 33, and resist shear at the center of the inner ring 32, preventing deformation.

[0034] A limiting groove 331 is provided on the pawl 33, and an installation ring 311 is provided on the ratchet ring 31. The function of the installation ring 311 is to prevent the pawl 33 from displacing axially along the support rod 321. The installation rings 311 are arranged at intervals along the ratchet ring 31. When the support rod 321 and pawl 33 are initially installed, the installation rings 311 play a positioning role to facilitate installation. When the positioning component 3 is not working, in order to prevent the pawl 33 from wearing due to long-term engagement with the ratchet ring 31 and the ratchet ring 31 from being subjected to local stress, the installation rings 311 also play a positioning role. When the ratchet ring 31 is damaged, the limiting groove 331 on the pawl 33 engages with the mounting ring 311 to press the pawl 33, causing the pawl 33 to disengage from the ratchet ring 31. When needed, the mounting ring 311 can be removed, and the pawl 33 will automatically engage with the ratchet for normal operation. Simultaneously, the limiting groove 331 provides a notch at the point where the pawl 33 engages with the ratchet ring 31, increasing the flow range of lubricating oil without affecting the operation of the ratchet ring 31, thus preventing excessive localized wear between the pawl 33 and the ratchet ring 31. The mounting rings 311 are spaced apart along the ratchet ring 31 for easy disassembly.

[0035] A lead screw 34 is fixedly connected to one end of the ratchet ring 31. The function of the lead screw 34 is to lock the axial rotational degree of freedom of the inner ring 32 through mutual coupling. When the motor 2 reverses, it only drives the ratchet ring 31 to rotate, while the inner ring 32 does not rotate, thereby locking the lead screw 34. At the same time, since the moving block cannot drive the lead screw 34 to rotate, the lead screw 34 locks the inner ring 32. Therefore, the lead screw 34 and the inner ring 32 form a mutual coupling self-lock. The cross section of the lead screw 34 is an isosceles trapezoid, which balances the load on both ends of the sliding block 35. The lead screw 34 clamps the automotive gearbox gear under the load from the sliding block 35. The thread helix angle of the lead screw 34 is smaller than the static friction angle, which prevents the sliding block 35 from driving the lead screw 34 to rotate, ensuring the stability of the shock absorption assembly 4 clamping the automotive gearbox gear and improving the load capacity. The thread helix angle of the lead screw 34 is larger than the inverse cosine angle between the hypotenuse and the base of the isosceles trapezoid, which reduces the time required for the clamping process and increases the displacement of the moving block relative to the lead screw 34 after one rotation. A sliding block 35 is slidably connected to the lead screw 34 to prevent the lead screw 34 from reversing. During the processing of the automotive gearbox gear, the position of the damping component 4 relative to the automotive gearbox gear remains unchanged, thereby restricting the sliding block 35 from moving. This prevents the sliding block 35 from driving the lead screw 34 to rotate when the self-locking effect between the sliding block 35 and the lead screw 34 fails. A retaining ring 36 is fixedly connected to one end of the sliding block 35. The retaining ring 36 clamps the workpiece by bearing the pressure of the damping component 4. The relative position of the retaining ring 36 and the moving block does not change. At the same time, since the moving block cannot drive the lead screw 34, it bears the stress generated by the damping component 4. At this time, this part of the stress is transmitted to the fixture through the retaining ring 36, and the automotive gearbox gear is clamped by restricting the degree of freedom of translation in the axial direction of the automotive gearbox gear.

[0036] When initially installing or replacing the ratchet ring 31, first mate the mounting ring 311 with the limiting groove 331 on the pawl 33, then install the pawl 33 on the support rod 321, and finally mate the inner ring 32 with the ratchet ring 31 to complete the installation or replacement of the part. Before machining the automotive gearbox gear, the motor 2 rotates forward, and the power of the motor 2 is transmitted to the ratchet ring 31 via the V-belt. The ratchet ring 31 rotates forward around the axis of the support rod 321. The ratchet ring 31 drives the inner ring 32 to rotate through the pawl 33, and the inner ring 32 drives the lead screw 34 to rotate. The lead screw 34 drives the sliding block to slide, thereby clamping the automotive gearbox gear. During the machining of the automotive gearbox gear, the motor 2 reverses, and the motor 2 drives the ratchet ring 31 to reverse through the V-belt assembly 1. At this time, the pawl 33 slides along the ratchet ring 31, while the inner ring 32 does not rotate. Since the inner ring 32 is fixedly connected to the lead screw 34, the lead screw 34 does not rotate, and the sliding block 35 cannot drive the lead screw 34 to rotate. The movement of the screw 34 ensures that the inner ring 32 cannot be rotated, thus achieving mutual coupling and self-locking between the inner ring 32 and the screw 34. Since the ratchet ring 31 and the pawl 33 constitute a ratchet mechanism, and the screw 34 and the moving block constitute a trapezoidal screw, both mechanisms have self-locking properties. The self-locking condition is that the helix angle is less than the static friction angle. When the mechanism is about to transmit power in the reverse direction, the friction force prevents the movement of the sliding block 35, thus achieving self-locking. Therefore, it is proven that the mutual coupling and self-locking effect design of this application is reasonable and ensures the stability of the automotive gearbox gear clamping. Before the tool contacts the workpiece, the tool first contacts the damping component 4. The stress on the damping component 4 is transmitted to the retaining ring 36. Since the retaining ring 36 is fixedly connected to the sliding block 35, the sliding block 35 is locked by the screw 34 and cannot move. Thus, the screw 34, the sliding block 35 and the retaining ring 36 jointly bear the load transmitted by the damping component 4, thereby preventing the positioning component 3 from wearing or being partially damaged.

[0037] As shown in Figures 1 to 8, a connecting shaft 42 is fixedly connected to the lower end of the gear chuck 41, and a transmission gear 43 is fixedly connected to the connecting shaft 42. A gear ring 44 is fixedly connected to the retaining ring 36. The transmission gear 43 meshes with the gear ring 44. The clockwise and counterclockwise rotation directions of the gear ring 44 provide two clamping methods for automotive gearbox gears of different sizes and processing positions. For smaller automotive gearbox gears or gearbox gears that require hole enlargement, the gear ring 44 rotates clockwise, the chuck retracts inward, and the clamping position is at the tip circle of the gear tooth. For larger automotive gearbox gears or gearbox gears that require shaving or grinding, the gear ring 44 rotates counterclockwise, the chuck expands outward, and the clamping position is at the axis of the automotive gearbox gear. This achieves the clamping of different sizes and processing positions. To achieve the desired flexible clamping effect for the gears, a spring 45 is fixedly connected to one side of the sliding block 35. A limit shaft 46 is fixedly connected to the end of the spring 45 away from the sliding block 35. A fixed plate 47 is slidably connected to the journal of the limit shaft 46 near the spring 45. A limit hole 471 is provided on the fixed plate 47. A connecting plate 48 is fixedly connected to the journal of the limit shaft 46 away from the spring 45. A straight slot 481 is provided on the connecting plate 48 to provide freedom of movement for the connecting plate 48. A sliding rod 49 is rotatably connected to the fixed plate 47, which supports the gear jaw 41 by changing its angle relative to the limit shaft 46. The sliding rod 49 swings around the hinge point between the sliding rod 49 and the fixed plate 47, thereby driving the connecting plate 48 to translate. The relative movement between the connecting plate 48 and the sliding rod 49 cancels out some vibration, thus protecting the jaw. The connecting plate 48 is shaped like a human figure, with its three endpoints labeled a, b, and c clockwise. A straight groove 481 is located at points a, b, and c. Since the stress on the connecting plate 48 primarily originates from the straight groove 481, which is situated at one of the endpoints, the human figure structure of the connecting plate 48 provides mutual support between the three endpoints, enhancing its stability and load-bearing capacity. This herringbone structure maintains balance under vertical loads, reducing deformation and displacement caused by uneven loads. Furthermore, the herringbone structure evenly distributes the load transmitted to the connecting plate 48 to each endpoint, allowing the entire structure to bear forces more uniformly. Compared to other structural forms, the herringbone structure effectively reduces localized stress, ensuring that the stress generated when the tool collides with the protrusion 491 is transmitted to the connecting plate via the slide bar 49. At any endpoint, the stress exerted on the connecting plate 48 by the slide bar 49 is evenly distributed, improving the structure's load-bearing and compressive strength. The bottom end of the slide bar 49 is connected to a protrusion 491. The protrusion 491 is fan-shaped to buffer the impact of the tool. When the tool contacts the slide bar 49, it first contacts the protrusion 491. The tool slides along the edge of the fan-shaped protrusion 491, which further delays the contact time between the tool and the gearbox gear. This prevents the tool from directly contacting the slide bar 49 and causing the slide bar 49 to fully bear the stress of the tool. The slide bar 49 is marked with scale lines. The slide bar 49 is slidably connected to the connecting plate 48, which assists the worker in reading the size of the workpiece through the swing of the slide bar 49.

[0038] As shown in Figure 2, the gear gripper 41 is a "hook" shape to accommodate different workpiece sizes. This, combined with the clockwise and counterclockwise rotation of the gear ring 44, allows for different clamping methods for gears of different sizes and processing requirements. Specifically, the "hook" shape consists of two smaller semicircles of equal radius and a larger semicircle. The radius of the smaller semicircle is x, and the radius of the larger semicircle is 2x. The two smaller semicircles are symmetrically arranged, and the larger semicircle connects to the smaller semicircle at both ends. The larger part of the arc formed by the "hook" shape is the outer side, and the smaller part is the inner side. The outer part of the "hook" shape contacts and locks with the ring at the axis of the automotive gearbox gear, while the inner side of the "hook" shape contacts and locks with the tip circle of the automotive gearbox gear. The arc-shaped surface provides better contact with the automotive gearbox gear. There are three gear grippers 41, and the centers of gravity of the three gear grippers 41 form an equilateral triangle. This utilizes three evenly distributed fulcrums relative to the axis of the automotive gearbox gear to clamp the gear, resulting in more stable stress bearing.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tooling fixture for automotive gearbox gears, comprising a V-belt assembly (1) and a motor (2) for driving the V-belt assembly (1), wherein the V-belt assembly (1) comprises a base (11), a bracket (12), a drive shaft (13), a drive pulley (14), a V-belt (15), and a driven pulley (16), characterized in that: It also includes a positioning component (3) and a shock-absorbing component (4). The V-belt assembly (1) is equipped with a positioning component (3) that can change its own position by mutual coupling and self-locking. The positioning component (3) is equipped with a shock-absorbing component (4). The function of the shock-absorbing component (4) is to change the relative position of the positioning component (3), thereby changing the workpiece clamping method. The positioning component (3) includes a ratchet ring (31), an inner ring (32), a support rod (321), a pawl (33), a lead screw (34), a sliding block (35), and a retaining ring (36). The driven wheel (16) is connected to the ratchet ring (31), and the inner ring (321) is fixedly connected inside the ratchet ring (31). 2) The function of the inner ring (32) is to change the magnitude and direction of the torque on the ratchet ring (31) by rotating the inner ring (32) forward and backward. A support rod (321) is fixedly connected in the inner ring (32), and a pawl (33) is rotatably connected to the support rod (321). A lead screw (34) is fixedly connected to one end of the ratchet ring (31). The function of the lead screw (34) is to lock the axial rotational freedom of the inner ring (32) through mutual coupling. A sliding block (35) is slidably connected on the lead screw (34) to prevent the lead screw (34) from reversing. A retaining ring (36) is fixedly connected to one end of the sliding block (35). The retaining ring (36) is supported by bearing... The shock-absorbing assembly (4) clamps the workpiece under pressure; the shock-absorbing assembly (4) includes a gear jaw (41), a connecting shaft (42), a transmission gear (43), a gear ring (44), a spring (45), a limiting shaft (46), a fixing plate (47), a limiting hole (471), a connecting plate (48), a straight groove (481), and a slide rod (49). The lower end of the gear jaw (41) is fixedly connected to the connecting shaft (42), the connecting shaft (42) is fixedly connected to the transmission gear (43), the retaining ring (36) is fixedly connected to the gear ring (44), the transmission gear (43) meshes with the gear ring (44), and one side of the sliding block (35) is fixedly connected to the connecting shaft (42). A spring (45) is connected to a limiting shaft (46) at the end of the spring (45) away from the sliding block (35). A fixing plate (47) is slidably connected to the limiting shaft (46) near the journal of the spring (45). A limiting hole (471) is opened on the fixing plate (47). A connecting plate (48) is fixedly connected to the limiting shaft (46) away from the journal of the spring (45). A straight slot (481) is opened on the connecting plate (48) to provide freedom of movement for the connecting plate (48). A sliding rod (49) is rotatably connected to the fixing plate (47) to support the gear jaw (41) by changing its angle relative to the limiting shaft (46).

2. The tooling fixture for automotive transmission gears according to claim 1, characterized in that: The axial section of the inner ring (32) is an I-shaped surface (322). The I-shaped surface (322) resists bending by increasing the moment of inertia at the fixed connection between the inner ring (32) and the support rod (321). The I-shaped surface (322) resists shear at the center of the inner ring (32).

3. The tooling fixture for automotive transmission gears according to claim 1, characterized in that: The pawl (33) has a limiting groove (331), and the ratchet ring (31) is provided with a mounting ring (311). The function of the mounting ring (311) is to prevent the pawl (33) from axially displacing along the support rod (321). The mounting rings (311) are arranged at intervals along the ratchet ring (31).

4. The tooling fixture for automotive transmission gears according to claim 1, characterized in that: The cross section of the lead screw (34) is an isosceles trapezoid, which balances the load on both ends of the sliding block (35). The thread helix angle of the lead screw (34) is smaller than the static friction angle, and the thread helix angle of the lead screw (34) is larger than the inverse cosine angle between the hypotenuse and the base of the isosceles trapezoid.

5. The tooling fixture for an automotive transmission gearbox according to claim 1, characterized in that: The gear gripper (41) is a "hook" shape to adapt to different workpiece sizes. There are three gear grippers (41), and the center of gravity of the three gear grippers (41) is located in an equilateral triangle.

6. The tooling fixture for automotive transmission gears according to claim 1, characterized in that: The connecting plate (48) is in the shape of a "human". The three endpoints of the connecting plate (48) are called points a, b, and c in clockwise order. The straight groove (481) is opened at points a, b, and c of the connecting plate (48). The straight groove (481) protects the connecting plate (48) by dispersing the local stress from the slide bar (49).

7. The tooling fixture for an automotive transmission gearbox according to claim 6, characterized in that: The bottom end of the slide bar (49) is connected to a protrusion (491), which is fan-shaped to buffer the impact of the tool.

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