Tooth turning clamp

Abstract

The gear turning clamp comprises a clamp body, a cone base and an expansion sleeve, the cone base is fixed to the clamp body, the interior of the cone base is hollow and connected with a pull sleeve in a sliding mode, the expansion sleeve is installed at the top end of the pull sleeve, and the expansion sleeve and the cone base are provided with inclined faces which are matched with each other and attached to each other. The clamp body is provided with a first driving source for driving the pulling sleeve to ascend and descend, a pressing claw used for pressing a workpiece and a second driving source for driving the pressing claw to ascend and descend, the pulling sleeve and the expansion sleeve are driven to move downwards through the first oil way, and the expansion sleeve expands and fixes the workpiece from the side direction by means of the abutting relation of the inclined faces. And the second oil way is combined to drive the pressing claw to move downwards to press and fix the workpiece in the vertical direction, multiple clamping and fixing of the workpiece are achieved, the better fixing effect is achieved, the good fixing effect can be achieved for all large-specification and large-size workpieces, and therefore the follow-up machining precision is ensured.

Description

Technical Field

[0001] The present invention relates to the field of fixtures, and in particular to a gear hobbing fixture. Background Art

[0002] A gear hobbing fixture is a device used to position and clamp a gear workpiece during the gear hobbing process, which can ensure that the workpiece is in the correct position during the gear hobbing process, enabling the cutting tool to cut the gear according to the design requirements and ensuring the final machining accuracy.

[0003] Currently, most gear hobbing fixtures use the method of expanding sleeves to fix the workpieces to be processed. In the actual machining process, there will be cases where some workpieces to be processed have a relatively large volume, such as large-diameter gear rings. At this time, if only the expanding sleeve is used for tightening and fixing, the fixing effect on the large-diameter gear ring will be poor, and there will be a situation where the workpiece is unstable during the machining process, affecting the machining accuracy, which needs to be further improved and perfected. Summary of the Invention

[0004] In order to further improve the clamping and fixing effect, the present application provides a gear hobbing fixture.

[0005] The present application provides a gear hobbing fixture, adopting the following technical solutions: A gear hobbing fixture includes a fixture body, a cone seat, and an expanding sleeve. The cone seat is fixed on the fixture body. The inside of the cone seat is hollow and slidably connected with a pull sleeve. The expanding sleeve is installed at the top of the pull sleeve. The expanding sleeve and the cone seat have inclined surfaces that match and fit each other. The fixture body is provided with a first driving source for driving the pull sleeve to move up and down. The fixture body is provided with a pawl for pressing the workpiece, and the fixture body is provided with a second driving source for driving the pawl to move up and down.

[0006] Optionally, a plurality of pawls are evenly distributed around the circumference, and the second driving source adopts a rotary clamping cylinder.

[0007] Optionally, a support seat is detachably connected to the fixture body. The support seat is located inside the cone seat and is used to support the workpiece.

[0008] Optionally, the support seat is fixedly connected to the fixture body by screws. A spacer sleeve is sleeved on the screws. The spacer sleeve is located between the fixture body and the support seat. A connecting plate is vertically slidably connected to the spacer sleeve, and the connecting plate is fixed to the pull sleeve.

[0009] Optionally, the connecting plate includes a connecting disk and a connecting seat. The connecting seat is fixedly connected to the connecting disk by screws, and the first driving source is connected to the connecting seat.

[0010] Optionally, a through hole is formed in the middle of the support base, the aperture of the through hole is larger than the outer diameter of the connecting base, a dust cover is inserted at the through hole, the height of the dust cover gradually decreases from the center to both sides, and chip removal grooves corresponding to each other and penetrating through are formed on the support base, the conical seat and the draw sleeve.

[0011] Optionally, the first driving source includes an oil cylinder, the oil cylinder includes a cylinder body and a piston body, the piston body is slidably connected in the cylinder body, the piston body is connected to the draw sleeve, a first oil passage connected to the oil cylinder is arranged on the fixture body, and a second oil passage connected to the rotary clamping cylinder is arranged on the fixture body.

[0012] Optionally, a chamber for the piston body to slide is provided in the cylinder body, the first oil passage includes a first oil inlet passage and a first oil outlet passage and is communicated with the chamber, a driving rod is horizontally slidably connected to the inner wall of the chamber, one end of the driving rod protrudes from the side wall of the sliding groove to form a driving end, a sliding groove for the driving rod to slide is formed in the cylinder body, the second oil passage passes through the sliding groove and forms an oil hole on the side wall of the sliding groove, a communication groove for communicating the oil hole is formed in the driving rod, when the piston body moves downwards to abut against the driving end, the driving rod retracts until the communication groove corresponds to and communicates with the oil hole to the second oil passage, and a reset member for driving the driving rod to reset is arranged in the cylinder body, and the reset member drives the driving rod to reset until its driving end protrudes from the inner wall of the chamber.

[0013] Optionally, one end of the sliding groove is communicated with the first oil passage, the end of the driving rod far from the driving end is a blocking end, when the communication groove corresponds to the oil hole, the blocking end is located in the first oil passage and blocks it.

[0014] Optionally, a movable sleeve is threadedly connected to the top end of the cylinder body corresponding to the chamber, and an operation hole is formed in the top end of the movable sleeve.

[0015] In summary, the present application includes at least one of the following beneficial technical effects: 1. The draw sleeve and the expansion sleeve are driven to move downwards through the first oil passage, and the expansion sleeve is tightened and fixed to the workpiece laterally by means of the abutting relationship of the inclined surface. Combined with the second oil passage driving the clamping jaw to move downwards to clamp and fix the workpiece in the vertical direction, multiple clamping and fixing of the workpiece are realized, achieving a better fixing effect, and good fixing effects can be achieved for large-sized workpieces, thereby ensuring the accuracy of subsequent processing; 2. The setting of the dust cover can effectively prevent the chips generated during the processing from falling into the oil cylinder below and affecting its normal operation, and the conical shape of the top of the dust cover can guide the chips to both sides, facilitating their discharge from the chip removal grooves on the side; 3. With the design of the sliding groove and the driving rod, when the piston is driven by the first oil circuit to move downward, driving the expansion sleeve to move downward to tighten the workpiece, the piston drives the driving rod to move horizontally until the communication groove corresponds to the oil hole, realizing the automatic connection of the second oil circuit. Thus, the second oil circuit automatically drives the clamping jaw to work and press down to clamp the workpiece, achieving the purpose of automatically clamping the workpiece with a delay after the expansion sleeve tightens and fixes the workpiece. And when the expansion sleeve does not tighten the workpiece, the second oil circuit is in a non-connected state, effectively preventing the phenomenon that the second oil circuit is accidentally opened, resulting in the clamping jaw accidentally clamping the workpiece. Description of the Drawings

[0016] Figure 1 is the overall structure diagram of Embodiment 1.

[0017] Figure 2 is the overall structure diagram of Embodiment 2.

[0018] Figure 3 is Figure 2 the enlarged view of A in

[0019] Figure 4 is the overall structure diagram of Embodiment 3.

[0020] Description of the Reference Numerals: 1. Clamping body; 2. Cone seat; 3. Expansion sleeve; 4. Screw; 5. Placing groove; 6. Pulling sleeve; 7. Workpiece; 8. Inclined surface; 9. First driving source; 10. Clamping jaw; 11. Rotary pressing cylinder; 12. Limiting hole; 13. Limiting groove; 14. Support seat; 15. Connecting plate; 16. Spacer sleeve; 17. Connecting disk; 18. Connecting seat; 19. Through groove; 20. Through hole; 21. Dust cover; 22. Chip removal groove; 23. Cylinder block; 24. Piston body; 25. Chamber; 26. Body; 27. Base; 28. First oil inlet circuit; 29. First oil outlet circuit; 30. Second oil inlet circuit; 31. Second oil outlet circuit; 32. Driving rod; 33. Sliding groove; 34. Driving end; 35. Guide surface; 36. Oil hole; 37. Communication groove; 38. Installation groove; 39. Return spring; 40. Sealing end; 41. Movable sleeve; 42. Operation hole; 43. Limiting strip; 44. Rotating pin. Detailed Embodiment

[0021] The following is a further detailed description of the present application in conjunction with the attached Figures 1-4 drawings.

[0022] Embodiment 1, a gear hobbing fixture, as Figure 1As shown in the figure, it includes a fixture body 1, a cone seat 2 and an expansion sleeve 3. The cone seat 2 is detachably fixed above the fixture body 1 by screws 4. The inside of the cone seat 2 is hollow to form a placement groove 5 for placing the workpiece 7. A pull sleeve 6 is vertically slidably connected in the placement groove 5. The expansion sleeve 3 is fixedly installed at the top of the pull sleeve 6. Both the expansion sleeve 3 and the pull sleeve 6 are located between the cone seat 2 and the workpiece 7. One side of the expansion sleeve 3 and the cone seat 2 that are in contact with each other has a matching inclined surface 8. A first driving source 9 for driving the pull sleeve 6 to move up and down vertically is arranged inside the fixture body 1. The first driving source 9 drives the pull sleeve 6 to move downwards, driving the expansion sleeve 3 to move downwards. By means of the contact of the inclined surface 8, the expansion sleeve 3 deforms and tightens to fix the workpiece 7, realizing the clamping and fixing of the workpiece 7 in the radial direction.

[0023] As Figure 1 shown, a clamping jaw 10 for pressing the workpiece 7 is arranged above the workpiece 7. A second driving source for driving the clamping jaw 10 to move up and down is arranged on the outer periphery of the fixture body 1. The second driving sources and the clamping jaws 10 are arranged in one-to-one correspondence and are evenly distributed around the circumference. The second driving source includes a rotary pressing cylinder 11. The clamping jaw 10 is fixedly arranged at the output end of the rotary pressing cylinder 11. The rotary pressing cylinder 11 can drive the clamping jaw 10 to rotate and move up and down vertically. In this way, before the workpiece 7 is installed, the clamping jaw 10 is driven to rotate horizontally and open, facilitating the placement of the workpiece 7 into the cone seat 2. Then, the clamping jaw 10 is driven to rotate above the workpiece 7 and descend to press the workpiece 7, realizing the pressing and fixing in the vertical direction.

[0024] Drive the pull sleeve 6 and the expansion sleeve 3 to move downwards and realize the expansion sleeve 3 to tighten and fix the workpiece 7 from the side by means of the contact relationship of the inclined surface 8. Combine with the downward movement of the clamping jaw 10 to press and fix the workpiece 7 in the vertical direction, realizing the multi-clamping and fixing of the workpiece 7, achieving a better fixing effect, and being able to achieve a good fixing effect for large-size workpieces 7 of large specifications, thus ensuring the accuracy of subsequent processing and being well applicable to the processing and use of large-size workpieces 7.

[0025] As Figure 1 shown, a limiting hole 12 is opened on one side of the cone seat 2. At the same time, a limiting groove 13 is opened on the expansion sleeve 3 corresponding to the limiting hole 12. The length direction of the limiting groove 13 is arranged vertically. In actual use, a limiting pin is installed at the limiting hole 12, and the end of the limiting pin extends into the limiting groove 13 to perform circumferential limiting on the expansion sleeve 3, thereby improving the stability of the expansion sleeve 3 and avoiding the phenomenon of circumferential rotation of the expansion sleeve 3 during use.

[0026] As Figure 1As shown in the figure, a support base 14 is detachably connected to the fixture body 1 by screws 4. The support base 14 is located inside the placement groove 5, and the top of the support base 14 is used to abut against the bottom of the workpiece 7, so as to provide good support for the workpiece 7 by means of the support base 14. In addition, a connecting plate 15 fixed to it is provided at the bottom of the pull sleeve 6. A spacer sleeve 16 is sleeved on the screw 4 of the support base 14. The connecting plate 15 is vertically slidably connected to the spacer sleeve 16. The top end of the spacer sleeve 16 abuts against the support base 14, and the bottom end of the spacer sleeve 16 abuts against the fixture body 1. The design of the spacer sleeve 16 enables the connecting plate 15 to slide vertically well. The spacer sleeve 16 can also protect the screw 4. While the screw 4 plays a role in connection and fixation, it can also play a role in guiding the vertical sliding of the connecting plate 15, realizing the multi-purpose of the screw 4.

[0027] As Figure 1 shown, the connecting plate 15 includes a connecting disk 17 and a connecting seat 18. The connecting seat 18 is detachably fixed to the middle of the connecting disk 17 by screws 4. A through groove 19 is provided in the middle of the connecting disk 17 for the connecting seat 18 to be inserted and matched. A vertical through hole 20 is provided in the middle of the support base 14. The outer diameter of the through hole 20 is larger than the outer diameter of the connecting seat 18. The design of the through hole 20 facilitates the installation of the connecting seat 18. At the same time, a dust-proof cover 21 is inserted and covered at the through hole 20. The dust-proof cover 21 is in transitional or interference fit with the through hole 20 to ensure the firmness of the insertion. The top wall of the dust-proof cover 21 is conically arranged, that is, the height of the dust-proof cover 21 gradually decreases from the middle to both sides. In this way, it can play a guiding role for debris and impurities, guiding the debris and impurities to the outside, and the debris and impurities will not accumulate on the dust-proof cover 21. In addition, corresponding and horizontally penetrating chip removal grooves 22 are provided on the support base 14, the cone seat 2 and the pull sleeve 6. The chip removal grooves 22 can play a role in corresponding chip removal.

[0028] The setting of the dust-proof cover 21 can effectively prevent the debris generated during the processing from falling into the oil cylinder below and affecting its normal operation. And the conical setting of the top of the dust-proof cover 21 can guide the debris to both sides, facilitating its discharge from the side chip removal grooves 22.

[0029] The split design of the connecting seat 18, the connecting disk 17 and the pull sleeve 6 makes the overall parts simpler, facilitating production and processing and also facilitating their independent installation. While reducing the production difficulty, it can also improve the convenience of installation and disassembly.

[0030] As Figure 1As shown in the figure, the first driving source 9 includes an oil cylinder, which is arranged inside the fixture body 1. The oil cylinder includes a cylinder block 23 and a piston body 24. The piston body 24 is slidably connected inside the cylinder block 23. There is a chamber 25 in the cylinder block 23 for the piston body 24 to slide. The cylinder block 23 includes a main body 26 and a base 27. A chamber 25 is formed between the base 27 and the main body 26. The piston body 24 is fixedly connected to the connecting seat 18. In this way, the sliding up and down of the piston body 24 can drive the up and down movement of the connecting seat 18, and finally achieve the vertical up and down movement of the draw sleeve 6 and the expansion sleeve 3, realizing the clamping and loosening of the workpiece 7. A first oil circuit communicating with the oil cylinder is provided on the fixture body 1. The first oil circuit includes a first oil inlet circuit 28 and a first oil outlet circuit 29. One end of the first oil inlet circuit 28 communicates with the chamber 25 above the piston body 24, and the first oil outlet circuit 29 communicates with the chamber 25 below the piston body 24. In this way, the sliding up and down of the piston body 24 in the chamber 25 can be realized by the alternating oil inlet of the first oil inlet circuit 28 and the first oil outlet circuit 29.

[0031] As Figure 1 shown in the figure, a second oil circuit for connecting with the rotary clamping cylinder 11 is also provided on the fixture body 1. The second oil circuit also includes a second oil inlet circuit 30 and a second oil outlet circuit 31. Based on the same principle as the first oil circuit, the vertical up and down movement of the clamping jaw 10 can be realized by the alternating switching of the second oil inlet circuit 30 and the second oil outlet circuit 31. The overall structure is more compact and can be well applied to some installation occasions without a driving cylinder, effectively improving the applicability.

[0032] Embodiment 2, a gear hobbing fixture, as Figure 2 and Figure 3As shown, the main difference from Embodiment 1 is that a horizontal driving rod 32 is provided on the inner wall of the chamber 25 corresponding to the vertical movement path of the piston body 24. The driving rod 32 is horizontally slidably connected to the base 27. A horizontal chute 33 for the driving rod 32 to slide is provided on the base 27. One end of the driving rod 32 protrudes from the inner wall of the chamber 25 to form a driving end 34. The top of the driving end 34 is an inclined guiding surface 35. In this way, during the downward movement of the piston body 24, abutting against the guiding surface 35 can drive the driving rod 32 to horizontally retract. The second oil inlet passage 30 passes through the chute 33 and communicates with it to form an oil hole 36. One end of the oil hole 36 communicates with the chute 33, and the other end communicates with the rotary clamping cylinder 11. At the same time, a communication groove 37 for communicating with the second oil inlet passage 30 is provided on the driving rod 32. The communication groove 37 penetrates the bottom wall of the driving rod 32. When the driving rod 32 is in the initial position, that is, when the driving end 34 of the driving rod 32 protrudes from the inner wall of the chamber 25, the communication groove 37 and the oil hole 36 are in a misaligned state. At this time, the oil hole 36 is blocked and closed by the driving rod 32, that is, the second oil inlet passage 30 is in a closed and non-communication state. After the piston body 24 moves downward to drive the driving rod 32 to completely retract, at this time, the expansion sleeve 3 expands and clamps the workpiece 7 tightly. The oil hole 36 corresponds to and communicates with the second oil inlet passage 30. At this time, the second oil inlet passage 30 is in a communicating state, and the oil enters the rotary clamping cylinder 11 to drive the clamping jaw 10 to rotate and move downward to clamp the workpiece 7 tightly to achieve further fixation.

[0033] In this way, with the design of the chute 33 and the driving rod 32, when the first oil passage drives the piston body 24 to move downward to drive the expansion sleeve 3 to move downward to clamp the workpiece 7 tightly, the piston body 24 drives the driving rod 32 to move horizontally until the communication groove 37 corresponds to the oil hole 36 to realize the automatic connection of the second oil passage. Thus, it automatically realizes that the second oil passage drives the clamping jaw 10 to work and press down to clamp the workpiece 7 tightly, achieving the purpose of the clamping jaw 10 automatically clamping the workpiece 7 with a delay after the expansion sleeve 3 clamps and fixes the workpiece 7. And when the expansion sleeve 3 does not clamp the workpiece 7 tightly, the second oil passage is in a non-communication state. In this way, it also effectively prevents the phenomenon that the second oil passage is accidentally opened and the clamping jaw 10 accidentally clamps the workpiece 7.

[0034] As Figure 2 and Figure 3 shown, a reset member for driving the driving rod 32 to move back to its original position is provided inside the base 27. The reset member is used to drive the driving rod 32 to move back to the state where its driving end 34 protrudes from the inner wall of the chamber 25, that is, to the state where the communication groove 37 and the oil hole 36 are in a misaligned state. The reset member includes a reset spring 39. An installation groove 38 for installing the reset spring 39 is provided inside the base 27. One end of the reset spring 39 is fixedly connected to the driving rod 32, and the other end is fixedly connected to the inner wall of the installation groove 38 of the seat body. In this way, when the piston body 24 moves upward to release the workpiece 7, the reset spring 39 can drive the driving rod 32 to reset, facilitating further use of clamping the workpiece 7 next time.

[0035] As Figure 2 andFigure 3 As shown, one end of the slide groove 33 away from the chamber 25 is connected to the first oil inlet 28, and the end of the driving rod 32 away from the driving end 34 is a blocking end 40, which is used to block the first oil inlet 28. When the driving rod 32 moves to the oil hole 36 and the connecting groove 37, the blocking end 40 blocks the first oil inlet 28, which has a certain pressure-maintaining effect on the oil in the chamber 25. The oil inlet of the first oil inlet 28 does not need to be in a continuous oil supply state, and the expansion sleeve 3 can still maintain a tightened state. state, realizing automatic closure of the first oil inlet 28 after the expansion sleeve 3 is tightened; the end of the blocking end 40 also has an inclined guide surface 35, so that when the piston body 24 moves up to release the workpiece 7, the oil in the upper cavity above the chamber 25 corresponding to the piston body 24 is not compressed much, and the pressure gradually increases until the piston body 24 moves up to the point where the drive rod 32 is misplaced, the oil pressure in the upper cavity and the reset spring 39 work together to drive the drive rod 32 to reset, the blocking end 40 retracts, and the first oil inlet 28 is opened to realize the reflux of oil.

[0036] like Figure 2 As shown, a movable sleeve 41 is threadedly connected above the main body 26 corresponding to the chamber 25, and an operating hole 42 is opened at the top of the movable sleeve 41. The bottom wall of the movable sleeve 41 serves as the top wall of the chamber 25, so that the upward movement stroke of the piston body 24 can be adjusted by rotating the movable sleeve 41, and when the dust cover 21 with interference fit is difficult to remove, the movable sleeve 41 can be adjusted to move upward so that the piston body 24 has a longer upward movement stroke, so that the piston body 24 drives the connecting seat 18 to move upward after the piston body 24 moves upward, and the connecting seat 18 can drive the dust cover 21 out of the through hole 20 after contacting the dust cover 21, thereby automatically driving the dust cover 21 to be disengaged, and no additional driving source is required, which is more convenient and labor-saving, realizes the multi-purpose of the piston body 24, and has better practicality.

[0037] Embodiment 3, a gear cutting fixture, such as Figure 4 As shown, the difference between it and Example 2 mainly lies in the different connection methods between the movable sleeve 41 and the main body 26. In this embodiment, the movable sleeve 41 is vertically slidably connected to the main body 26, and a limit strip 43 is arranged on the top wall of the cylinder body 23. The middle part of the limit strip 43 is rotatably connected to the main body 26 by means of a rotating pin 44. The rotating pin 44 is eccentrically arranged, and one end of the rotating pin 44 is rotated to press on the movable sleeve 41 to limit its vertical position. The vertical sliding connection method of the movable sleeve 41 can realize the quick adjustment and disassembly of the movable sleeve 41. Only after the limit strip 43 is turned open, the movable sleeve 41 can be synchronously moved upward under the drive of the piston body 24 to realize the driving and disengagement of the dust cover 21. After completion, the piston body 24 and the movable sleeve 41 are synchronously moved downward and reset, and the limit strip 43 is rotated so that its end presses the movable sleeve 41 to limit its upward movement. The operation is simple and convenient.

[0038] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A gear cutting fixture, characterized in that: The invention comprises a clamp body (1), a cone seat (2) and an expansion sleeve (3), wherein the cone seat (2) is fixed on the clamp body (1), the cone seat (2) is hollow inside and is slidably connected with a pull sleeve (6), the expansion sleeve (3) is installed on the top end of the pull sleeve (6), the expansion sleeve (3) and the cone seat (2) have mutually matching and fitting inclined surfaces (8), the clamp body (1) is provided with a first driving source (9) for driving the pull sleeve (6) to rise and fall, the clamp body (1) is provided with a pressing claw (10) for pressing a workpiece (7), and the clamp body (1) is provided with a second driving source for driving the pressing claw (10) to rise and fall.

2. A gear cutting fixture according to claim 1, characterized in that: The plurality of pressing claws (10) are evenly distributed around the circumference, and the second driving source is a rotary pressing cylinder (11).

3. A gear cutting fixture according to claim 2, characterized in that: A support seat (14) is detachably connected to the clamp body (1); the support seat (14) is located inside the cone seat (2) and is used to support the workpiece (7).

4. A gear cutting fixture according to claim 3, characterized in that: The support seat (14) is connected and fixed to the clamp body (1) by means of screws (4); a spacer sleeve (16) is sleeved on the screws (4); the spacer sleeve (16) is located between the clamp body (1) and the support seat (14); a connecting plate (15) is vertically slidably connected to the spacer sleeve (16); and the connecting plate (15) is fixed to the pull sleeve (6).

5. A gear cutting fixture according to claim 4, characterized in that: The connecting plate (15) comprises a connecting disk (17) and a connecting seat (18); the connecting seat (18) and the connecting disk (17) are connected and fixed by screws (4); and the first driving source (9) is connected to the connecting seat (18).

6. A gear cutting fixture according to claim 5, characterized in that: A through hole (20) is provided in the middle of the support seat (14), the aperture of the through hole (20) is larger than the outer diameter of the connecting seat (18), a dust cover (21) is inserted into the through hole (20), the height of the dust cover (21) gradually decreases from the center to both sides, and corresponding and penetrating chip grooves (22) are provided on the support seat (14), the cone seat (2) and the pulling sleeve (6).

7. A gear cutting fixture according to claim 2 or 6, characterized in that: The first driving source (9) comprises an oil cylinder, the oil cylinder comprises a cylinder body (23) and a piston body (24), the piston body (24) is slidably connected in the cylinder body (23), the piston body (24) is connected to the pulling sleeve (6), the clamp body (1) is provided with a first oil circuit connected to the oil cylinder, and the clamp body (1) is provided with a second oil circuit connected to the rotary clamping cylinder (11).

8. A gear cutting fixture according to claim 7, characterized in that: The cylinder body (23) has a chamber (25) in which the piston body (24) slides. The first oil circuit includes a first oil inlet circuit (28) and a first oil outlet circuit (29), both of which are in communication with the chamber (25). A driving rod (32) is horizontally slidably connected to the inner wall of the chamber (25). One end of the driving rod (32) protrudes from the side wall of the slide groove (33) to form a driving end (34). The cylinder body (23) is provided with a slide groove (33) in which the driving rod (32) slides. The second oil circuit passes through the slide groove (33). ) and an oil hole (36) is formed on the side wall of the slide groove (33); the driving rod (32) is provided with a connecting groove (37) for connecting with the oil hole (36); the piston body (24) moves downward to abut against the driving end (34) to drive the driving rod (32) to retract to the connecting groove (37) and to connect with the oil hole (36) to a second oil path; a reset member for driving the driving rod (32) to reset is arranged in the cylinder body (23); the reset member drives the driving rod (32) to reset until its driving end (34) protrudes from the inner wall of the chamber (25).

9. The gear cutting fixture according to claim 8, characterized in that: One end of the slide groove (33) is connected to the first oil inlet path (28), and the end of the drive rod (32) away from the drive end (34) is a blocking end (40). When the connecting groove (37) corresponds to the oil hole (36), the blocking end (40) is located in the first oil inlet path (28) and blocks it.

10. The gear cutting fixture according to claim 7, characterized in that: A movable sleeve (41) is threadedly connected to the top end of the cylinder body (23) corresponding to the chamber (25), and an operating hole (42) is formed at the top end of the movable sleeve (41).

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