A hydraulic chuck based special fixture for gear hole grinding

Abstract

The utility model relates to gear processing technical field discloses a special fixture of gear hole grinding based on hydraulic chuck, including hydraulic chuck, each fixed with a connecting block on three clamping claws of hydraulic chuck, and the locating pinion is connected through locking assembly on connecting block, and three locating pinions are about the center of hydraulic chuck and are set in circle and are distributed evenly. Through the meshing of three circle and evenly distributed locating pinions and the gear to be processed, the center positioning is realized, the accurate drive characteristic of gear meshing is utilized, the positioning deviation caused by the irregular structure of traditional three -jaw chuck clamping gear outside is avoided, and the center positioning precision of the gear to be processed is improved obviously.

Description

Technical Field

[0001] This utility model relates to the field of gear processing technology, and in particular to a special fixture for grinding the inner hole of gears based on a hydraulic chuck. Background Technology

[0002] In gear manufacturing, the precision of the inner bore directly affects the gear's assembly performance and transmission accuracy; therefore, grinding the gear's inner bore is a critical process. Currently, gear inner bore grinding typically uses a three-jaw chuck to directly clamp the gear's outer cylindrical surface for positioning. However, due to the structural characteristics of gears, their outer cylindrical surface is not a perfectly smooth cylinder; it often contains tooth grooves, protrusions, or other irregular structures. When using a traditional three-jaw chuck to clamp the outer side of the gear, the contact point between the chuck jaws and the gear's outer diameter is easily affected by tooth grooves and protrusions, leading to uneven clamping force distribution and consequently, gear center positioning deviation. This inaccurate positioning causes the ground inner bore to be misaligned with the gear's reference axis, severely affecting the gear's machining quality and performance, increasing scrap rate and production costs. To address these issues, there is an urgent need for a fixture capable of achieving high-precision gear center positioning to improve the accuracy and stability of gear inner bore grinding. Utility Model Content

[0003] The purpose of this invention is to provide a special fixture for grinding the inner hole of a gear based on a hydraulic chuck. By meshing a small gear with the large gear to be processed, the fixture achieves high-precision center positioning of the large gear, thus ensuring the quality of the inner hole grinding process.

[0004] The above-mentioned technical objective of this utility model is achieved through the following technical solution: A special fixture for grinding the inner hole of a gear based on a hydraulic chuck includes a hydraulic chuck. Each of the three jaws of the hydraulic chuck is fixed with a connecting block. A positioning pinion is connected to the connecting block through a locking assembly. The three positioning pinions are evenly distributed in a circle about the center of the hydraulic chuck.

[0005] When grinding the inner bore of a gear, the large gear to be ground is placed between three locating pinions. A hydraulic chuck is then driven, and its jaws, via connecting blocks, move the three locating pinions towards the large gear simultaneously. The large gear is eventually clamped between the three locating pinions, and a locking assembly secures the pinions to prevent them from rotating. This meshing relationship between the gears clamps the large gear, improving its centering accuracy. Once the large gear is positioned, the grinding head of the grinding machine extends into its inner bore and performs grinding along its circular path. After grinding, the jaws move outward, disengaging the locating pinions from the finished large gear.

[0006] Preferably, the positioning pinion has a tapered hole formed on it; The locking assembly includes a locking part inserted into a tapered hole and a first hydraulic cylinder for pushing and pulling the locking part; the first hydraulic cylinder is fixed to the outer end of the chuck, and the first hydraulic cylinder is connected to the hydraulic station through a solenoid valve, oil pipe, etc., and the controller controls the hydraulic station, solenoid valve and hydraulic chuck; the piston rod of the first hydraulic cylinder is fixedly connected to the locking part.

[0007] The locking part includes an integrally formed conical head and a cylindrical tie rod. The outer wall slope of the conical head is equal to the inner wall slope of the conical hole. The cylindrical tie rod is inserted into a guide hole that is clearance-fitted with it. The guide hole is formed on the connecting block.

[0008] During the process of clamping the large gear's inner bore with the positioning pinion, the outer wall of the conical head detaches from the inner wall of the conical hole. The positioning pinion can rotate accordingly with the position change of the large gear during clamping to adapt to it. After the large gear is machined, the piston rod of the first cylinder retracts, causing the locking part to move downwards. The conical head of the locking part presses tightly against the inner wall of the conical hole. Simultaneously, the downward pressure of the locking part causes the lower end face of the positioning pinion to press firmly against the connecting block. The static friction between the positioning pinion and the connecting block, and the friction between the conical head and the conical hole, secure the positioning pinion, preventing its rotation. This, in turn, prevents the large gear from rotating during inner bore grinding, enhancing the stability of the large gear during grinding.

[0009] Preferably, the bottom surface of the guide hole is formed with a square hole; The lower end of the cylindrical tie rod is formed with a square column, which is inserted into a square hole. When the piston rod of the first cylinder extends, the square column moves up to the top of the square hole. When the piston rod of the first cylinder retracts, the square column is inserted into the square hole. The square hole restricts the square column, thereby preventing the locking part from rotating. This further prevents the positioning pinion from rotating and further improves the stability of the grinding inner hole.

[0010] Preferably, the piston rod of the first hydraulic cylinder is eccentrically positioned with respect to the cylindrical tie rod. When the square column is pushed upwards and disengaged from the square hole by the piston rod of the first hydraulic cylinder, the eccentric action of the piston rod and the cylindrical tie rod prevents the locking part from rotating in any state, thereby avoiding the rotation of the positioning pinion causing the locking part to rotate.

[0011] Preferably, the positioning pinion has a stepped hole formed on it; The locking assembly includes a screw that is inserted into a stepped hole and screwed onto the connecting block; The outer diameter of the screw is fitted with the inner diameter of the small diameter hole of the stepped hole with a clearance, which can improve the positional accuracy between the positioning pinion and the screw.

[0012] This technical solution is another locking method for positioning the pinion. After the large gear is positioned, the screw is rotated by a tool, and the screw makes the positioning pinion fit tightly against the connecting block, thereby fixing the positioning pinion. This manual locking method can significantly reduce the manufacturing cost of the fixture and achieve the same fastening effect.

[0013] Preferably, the hydraulic chuck has multiple clamping components fixed on its body; The clamping assembly includes a support fixedly connected to the main body, a second hydraulic cylinder is provided on the support, a pressure block is fixed to the end of the piston rod of the second hydraulic cylinder, the second hydraulic cylinder is connected to the hydraulic station through a solenoid valve and an oil pipe, and the controller is electrically connected to the corresponding solenoid valve.

[0014] After the large gear is clamped by the positioning small gear and the center positioning is completed, the piston rod of the second oil cylinder retracts and drives the pressure block to move down. The pressure block moves down and presses against the upper end surface of the large gear to be ground, thereby further pressing the large gear and preventing the large gear from moving axially during the grinding process.

[0015] Preferably, the second hydraulic cylinder is a rotary cylinder. The piston rod of the rotary cylinder rotates at a 90-degree angle, which enables the automatic rotation of the pressure block. When the large gear is inserted or removed, the pressure block rotates to the outer area where the large gear is inserted, facilitating the insertion or removal of the large gear.

[0016] Preferably, the second hydraulic cylinder is fixed to a rectangular block located on its lower side; The support has a rectangular hole with an opening on the upper side, and the rectangular block is inserted into the rectangular hole. The bottom of the rectangular elongated hole is formed with an oblong hole; at least two second screws are inserted into the oblong hole and screwed onto the rectangular block. Loosening the second screws allows the rectangular block to move radially within the rectangular elongated hole, which in turn moves the second hydraulic cylinder to adjust its position, thus adapting to the clamping operation of large gears of different diameters.

[0017] The outstanding effect of this utility model is: Compared with existing technologies, center positioning is achieved by meshing three circumferentially distributed positioning pinions with the large gear to be processed. By utilizing the precise transmission characteristics of gear meshing, the positioning deviation caused by the irregular structure of the outer side of the gear clamped by the traditional three-jaw chuck is avoided, and the center positioning accuracy of the large gear to be processed is significantly improved.

[0018] The locking assembly locks the positioning pinion, effectively preventing the pinion and gear from rotating during grinding. At the same time, the clamping assembly prevents the gear from moving axially, further ensuring the stability of the machining process.

[0019] The position of the clamping component is adjustable to accommodate large gears of different diameters; and it offers two locking methods that can be selected according to actual production needs, lowering the barrier to entry for use. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a top view of the present invention; Figure 3 for Figure 2 A sectional view of AA; Figure 4 This is a schematic diagram of the second embodiment of the present invention.

[0021] Reference numerals: 1. Hydraulic chuck; 11. Chuck; 12. Body; 2. Connecting block; 201. Guide hole; 202. Square hole; 3. Positioning pinion; 301, tapered hole; 304, stepped hole; 4. Locking assembly; 41. Locking part; 42. First hydraulic cylinder; 44. Screw; 411. Conical head; 412. Cylindrical tie rod; 413. Square column; 5. Clamping assembly; 51. Support; 52. Second hydraulic cylinder; 53. Pressure block; 54. Rectangular block; 55. Rectangular elongated hole; 56. Oblong hole; 57. Second screw; 9. Large gear to be processed. Detailed Implementation

[0022] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0023] The following is for reference Figures 1 to 4 The present invention will be described as follows: Example 1

[0024] like Figure 1 , Figure 2 As shown, a special fixture for grinding the inner hole of a gear based on a hydraulic chuck includes a hydraulic chuck 1. Each of the three jaws 11 of the hydraulic chuck 1 is fixed with a connecting block 2 by bolts. A positioning pinion 3 is connected to the connecting block 2 by a locking assembly 4. The three positioning pinions 3 are evenly distributed circumferentially about the center of the hydraulic chuck 1. Three clamping assemblies 5 are fixed on the body 12 of the hydraulic chuck 1.

[0025] like Figure 3As shown, the positioning pinion 3 has a tapered hole 301 formed on it; the locking assembly 4 includes a locking part 41 inserted into the tapered hole 301 and a first hydraulic cylinder 42 for pushing and pulling the locking part 41; the first hydraulic cylinder 42 is fixed to the outer end of the chuck by bolts, and the first hydraulic cylinder is connected to the hydraulic station through a solenoid valve, oil pipe, etc. The controller controls the hydraulic station, solenoid valve and hydraulic chuck; the piston rod of the first hydraulic cylinder is fixed to the locking part by a threaded connection.

[0026] The locking part 41 includes an integrally formed conical head 411 and a cylindrical pull rod 412. The outer wall slope of the conical head 411 is equal to the inner wall slope of the conical hole 301. The cylindrical pull rod 412 is inserted into the guide hole 201 with clearance fit. The guide hole 201 is formed on the connecting block 2.

[0027] The bottom surface of the guide hole 201 is formed with a square hole 202; the lower end of the cylindrical tie rod 412 is formed with a square column 413, which is inserted into the square hole 202. The piston rod of the first oil cylinder 42 is eccentrically positioned with respect to the cylindrical tie rod 412.

[0028] like Figure 1 As shown, the clamping assembly 5 includes a support 51 that is fixedly connected to the body 12 by bolts. A second hydraulic cylinder 52 is provided on the support 51. The second hydraulic cylinder 52 is a rotary hydraulic cylinder with a piston rod rotation angle of 90 degrees. A pressure block 53 is fixed to the end of the piston rod of the second hydraulic cylinder 52 by bolts. The second hydraulic cylinder 52 is connected to the hydraulic station through a solenoid valve and an oil pipe. The controller is electrically connected to the corresponding solenoid valve.

[0029] The second hydraulic cylinder 52 is fixed to a rectangular block 54 located below it. A rectangular elongated hole 55 with an upper opening is formed inside the support 51, and the rectangular block 54 is inserted into the rectangular elongated hole 55. A waist-shaped hole 56 is formed at the bottom of the rectangular elongated hole 55. Two second screws 57 are inserted into the waist-shaped hole 56 and screwed onto the rectangular block 54. Loosening the second screws 57 allows the rectangular block 54 to move radially within the rectangular elongated hole. The rectangular block drives the second hydraulic cylinder to move, thereby adjusting the position of the second hydraulic cylinder 52, thus adapting to the clamping operation of large gears of different diameters.

[0030] The working process of this embodiment is as follows: When grinding is required on the inner bore of the gear, the controller controls the piston rod of the second cylinder 52 to rotate 90 degrees, so that the pressure block 53 rotates to the outside of the large gear placement area, and places the large gear 9 whose inner bore needs to be ground between the three positioning pinions.

[0031] The piston rod of the first cylinder 42 extends, the outer wall of the conical head 411 disengages from the inner wall of the conical hole 301, the square column 413 moves up to the top of the square hole 202, the controller drives the hydraulic chuck 1, the jaws 11 of the hydraulic chuck drive the three positioning pinions 3 to move towards the large gear at the same time through the connecting block 2, the positioning pinions 3 can rotate accordingly with the position change of the large gear to adapt to the large gear, and finally the large gear is clamped between the three positioning pinions.

[0032] Then, the controller controls the piston rod of the first cylinder 42 to retract, causing the locking part 41 to move down. The conical head 411 of the locking part is pressed tightly against the inner wall of the conical hole 301, and the square post 413 is inserted into the square hole 202. Through the static friction between the positioning pinion and the connecting block, the friction between the conical head and the conical hole, and the limiting effect of the square hole on the square post, the positioning pinion is tightened to prevent it from rotating.

[0033] Next, the controller controls the piston rod of the second cylinder 52 to rotate 90 degrees in the opposite direction and then retract, causing the pressure block 53 to move down and press against the upper end surface of the large gear, further pressing the large gear.

[0034] Then, the grinding head of the grinding machine extends into the inner hole of the large gear and moves in a circular motion along the inner hole to perform grinding.

[0035] After processing, the controller controls the piston rod of the second cylinder 52 to extend, causing the pressure block to move upward and then rotate 90 degrees to the outside; controls the piston rod of the first cylinder 42 to extend, causing the conical head to disengage from the conical hole and the square column to move upward above the square hole; controls the jaws of the hydraulic chuck to move outward, causing the positioning pinion to disengage from the processed large gear, and the large gear can then be removed. Example 2

[0036] The difference between this embodiment and Embodiment 1 lies in the structure of the locking component 4. In this embodiment, the positioning pinion 3 has a stepped hole 304 formed on it; the locking component 4 includes a screw 44 inserted into the stepped hole 304, and the screw 44 is screwed onto the connecting block 2; the outer diameter of the screw 44 is clearance-fitted with the inner diameter of the small diameter hole of the stepped hole 304.

[0037] In this embodiment, after the large gear is clamped by the three positioning pinions, the screw 44 is rotated using a wrench or other tools to make the positioning pinions fit tightly against the connecting block, thereby fixing the positioning pinions. After processing is completed, the positioning pinions can be loosened by rotating the screw in the opposite direction. The rest of the working process is the same as in Embodiment 1.

[0038] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model. These improvements and modifications assumed above should also be considered within the protection scope of the present utility model.

Claims

1. A special fixture for grinding the inner hole of a gear based on a hydraulic chuck, comprising a hydraulic chuck (1), characterized in that: Each of the three jaws (11) of the hydraulic chuck (1) is fixed with a connecting block (2). The connecting block (2) is connected to a positioning pinion (3) through a locking assembly (4). The three positioning pinions (3) are evenly distributed around the center of the hydraulic chuck (1). The positioning pinion (3) has a tapered hole (301) formed on it. The locking assembly (4) includes a locking part (41) inserted into a tapered hole (301) and a first hydraulic cylinder (42) for pushing and pulling the locking part (41). The locking part (41) includes an integrally formed conical head (411) and a cylindrical pull rod (412). The outer wall slope of the conical head (411) is equal to the inner wall slope of the conical hole (301). The cylindrical pull rod (412) is inserted into the guide hole (201) with clearance fit.

2. The gear grinding inner hole special fixture based on a hydraulic chuck according to claim 1, characterized in that: The bottom surface of the guide hole (201) is formed with a square hole (202). The lower end of the cylindrical tie rod (412) is formed with a square column (413), which is inserted into the square hole (202).

3. A special fixture for grinding gear inner holes based on a hydraulic chuck according to claim 2, characterized in that: The piston rod of the first oil cylinder (42) is eccentrically set with respect to the cylindrical tie rod (412).

4. A special fixture for grinding gear inner holes based on a hydraulic chuck according to claim 1, characterized in that: The positioning pinion (3) has a stepped hole (304) formed on it. The locking assembly (4) includes a screw (44) inserted into a stepped hole (304) and screwed onto the connecting block (2); The outer diameter of the screw (44) is fitted with the inner diameter of the small diameter hole of the stepped hole (304) with clearance.

5. A special fixture for grinding gear inner holes based on a hydraulic chuck according to any one of claims 1-4, characterized in that: Multiple clamping components (5) are fixed on the body (12) of the hydraulic chuck (1); The clamping assembly (5) includes a support (51) fixedly connected to the body (12), a second oil cylinder (52) is provided on the support (51), and a pressure block (53) is fixed to the end of the piston rod of the second oil cylinder (52).

6. A special fixture for grinding gear inner holes based on a hydraulic chuck according to claim 5, characterized in that: The second hydraulic cylinder (52) is a rotary hydraulic cylinder.

7. A special fixture for grinding gear inner holes based on a hydraulic chuck according to claim 6, characterized in that: The second hydraulic cylinder (52) is fixed to a rectangular block (54) located on its lower side; The support (51) has a rectangular long hole (55) with an opening on the upper side, and the rectangular block (54) is inserted into the rectangular long hole (55). The bottom of the rectangular elongated hole (55) is formed with a waist-shaped hole (56); at least two second screws (57) are inserted into the waist-shaped hole (56), and the at least two second screws (57) are screwed onto the rectangular block (54).

Images