An adaptive fixture for machining a drive shaft

Abstract

The utility model relates to drive shaft clamp technical field especially relates to a kind of self-adapting fixture for drive shaft processing, including base, base top is connected with fixed plate, and fixed plate top is provided with moving plate, and first motor is installed in moving plate middle part, and first motor output shaft is connected with screw rod, and screw rod is rotatably connected with moving plate, and screw rod is threadedly connected with fixed plate, and moving plate bottom is connected with guide rod, and guide rod is slidably connected in fixed plate, and electric push rod is installed in the outside of fixed plate and moving plate, and electric push rod is connected with pressing plate, and pressing plate is connected with runner, and pressing plate is installed with second motor, and the output shaft of second motor is connected with the axle of runner. By the electric push rod installed in the outside of fixed plate and moving plate synchronously push pressing plate, make runner at the end of pressing plate evenly extrude drive shaft from both sides, form symmetrical stress structure, realize the balanced distribution of clamping force, reach the purpose of surface friction damage in moving process.

Description

Technical Field

[0001] This utility model relates to the field of drive shaft fixture technology, and in particular to an adaptive fixture for drive shaft machining. Background Technology

[0002] The drive shaft is a core component of an automotive transmission system, primarily used to transmit the torque generated by the engine from the gearbox to the wheels. Its structural precision and surface quality directly affect the vehicle's ride smoothness, transmission efficiency, and service life. With the automotive industry's increasing demands for lightweight and high reliability, the machining precision requirements for drive shafts are constantly rising, especially regarding the strict control of surface roughness, coaxiality, and dimensional tolerances. Therefore, achieving efficient and damage-free clamping of drive shafts during machining has become a key technical challenge in the industry.

[0003] In existing drive shaft machining clamping equipment, traditional fixed clamps are difficult to adapt to the machining needs of drive shafts of various specifications due to their poor adjustment flexibility. A semi-automatic clamp for automotive drive shaft machining, with announcement number CN221621932U, achieves overall clamp height adjustment through a lifting mechanism and uses a sliding bar structure to complete the front and rear positioning of the drive shaft. While this design improves clamping efficiency to some extent, the core driving method still relies on the squeezing action of a single-sided cylinder, using static friction to drive the drive shaft to slide and adjust its position.

[0004] The compressive force applied by a single cylinder can cause uneven stress on the drive shaft. During sliding, the static friction on the compressed side increases with the pressure, while the static friction on the other side, which is not directly compressed, also increases abnormally due to the relative sliding between the shaft and the fixture. This asymmetrical stress state not only exacerbates the risk of scratches and deformation on the drive shaft surface, but may also lead to local stress concentration on the shaft, affecting machining accuracy and yield. Utility Model Content

[0005] To overcome the drawback of easy friction damage from single-sided drive, this invention provides an adaptive fixture for machining drive shafts, aiming to solve the above-mentioned shortcomings.

[0006] An adaptive fixture for machining drive shafts includes a base, a fixed plate connected to the top of the base, a movable plate disposed on the top of the fixed plate, the fixed plate and the movable plate forming a partially circular tube, a first motor mounted in the middle of the movable plate, a lead screw connected to the output shaft of the first motor, the lead screw being rotatably connected to the movable plate and threadedly connected to the fixed plate, a guide rod connected to the bottom of the movable plate, the guide rod being slidably connected inside the fixed plate, electric push rods mounted on the outer sides of both the fixed plate and the movable plate, the piston rod of the electric push rod passing through the fixed plate or the movable plate and connected to a pressure plate, a rotating wheel rotatably connected to one end of the pressure plate facing the center of the circular tube, a second motor mounted on the pressure plate, the output shaft of the second motor being connected to the axis of the rotating wheel.

[0007] Further explanation includes: a first rack is slidably connected to the bottom of the top pressure plate; a counterweight is connected to the bottom of the first rack; a gear is rotatably connected to the bottom of the pressure plate; a second rack is slidably connected inside the pressure plate; the first rack and the second rack are respectively located on both sides of the gear; both the first rack and the second rack mesh with the gear; a control valve is installed at the bottom of the second rack; and a suction nozzle is connected to the bottom of the control valve.

[0008] To further explain, a protective pad is connected to the bottom of the counterweight.

[0009] To further explain, a return spring is provided inside the pressure plate, the bottom end of the return spring is connected to the top of the first rack, and the top end of the return spring is connected inside the pressure plate.

[0010] To further explain, rubber rings are fitted at both ends of the rotating wheel.

[0011] To further explain, the base is equipped with adjustable feet at its bottom.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] 1. The pressure plate is pushed synchronously by electric push rods installed on the outer sides of both the fixed plate and the moving plate, so that the rotating wheel at the end of the pressure plate squeezes the drive shaft evenly from both sides, forming a symmetrical force structure, realizing a balanced distribution of clamping force, and achieving the purpose of eliminating surface friction damage during the movement.

[0014] 2. The rubber rings fitted at both ends of the roller generate radial elastic deformation when squeezed by the pressure plate. The rubber rings form elastic contact with the surface of the drive shaft. The friction of the rubber rings drives the drive shaft to roll, achieving smooth movement of the drive shaft and reducing surface scratches caused by sliding friction.

[0015] 3. The transmission mechanism, consisting of a first rack, a gear, and a second rack that are slidably connected at the bottom of the top pressure plate, pushes the first rack to slide when the counterweight is pressed down. The gear drives the second rack to lower the control valve and the suction nozzle. After the suction nozzle comes into contact with the top surface of the drive shaft, it forms a negative pressure adsorption, achieving dual fixation by mechanical extrusion and vacuum adsorption, enhancing the fixation stability of the drive shaft and preventing axial or circumferential displacement. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0017] Figure 2 This is a cross-sectional view showing the connection relationship between the first motor and the lead screw of this utility model.

[0018] Figure 3 This is a cross-sectional view of the specific structure of the electric push rod and pressure plate of this utility model.

[0019] Figure 4 This is a cross-sectional view showing the connection relationship between the first rack and gear of this utility model.

[0020] The markings in the attached diagram are as follows: 1: base, 2: fixed plate, 3: moving plate, 4: first motor, 5: lead screw, 6: guide rod, 7: electric push rod, 8: pressure plate, 9: rotating wheel, 10: second motor, 11: first rack, 12: counterweight, 13: gear, 14: second rack, 15: control valve, 16: suction nozzle, 17: protective pad, 18: return spring, 19: rubber ring, 20: adjusting foot. Detailed Implementation

[0021] The present invention will now be described more fully below with reference to the accompanying drawings, in which presently preferred embodiments of the invention are shown. However, the present invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and to fully convey the scope of the invention to those skilled in the art.

[0022] Example: An adaptive fixture for machining drive shafts, such as Figures 1-4As shown, the system includes a base 1, a fixed plate 2, a movable plate 3, a first motor 4, a lead screw 5, a guide rod 6, an electric push rod 7, a pressure plate 8, a rotating wheel 9, and a second motor 10. The fixed plate 2 is connected to the top of the base 1. The contact surface between the fixed plate 2 and the base 1 is precision machined to ensure perpendicularity. The movable plate 3 is mounted on the top of the fixed plate 2. The fixed plate 2 and the movable plate 3 form a partially circular tube with an opening angle of 80° to facilitate radial insertion of the drive shaft. The first motor 4 is installed in the middle of the movable plate 3. The output shaft of the first motor 4 is connected to the lead screw 5, which is rotatably connected to the movable plate 3. The fixed plate 2 is threadedly connected to the bottom of the movable plate 3, which is connected to the guide rod 6. The guide rod 6 is slidably connected inside the fixed plate 2. The length of the guide rod 6 and the lead screw 5 inserted into the base 1 is greater than the radius of the fixed plate 2. Electric push rods 7 are installed on the left and right sides and the bottom of the fixed plate 2. Electric push rods 7 are installed on the top of the movable plate 3. The piston rod of the electric push rod 7 passes through the fixed plate 2 or the movable plate 3 and is connected to the pressure plate 8. The pressure plate 8 is rotated and connected to the rotating wheel 9 on the side facing the center of the missing tube. A second motor 10 is installed on the side of the pressure plate 8. The output shaft of the second motor 10 is connected to the axis of the rotating wheel 9.

[0023] like Figure 3 and Figure 4 As shown, it also includes a first rack 11, a counterweight 12, a gear 13, a second rack 14, a control valve 15, and a suction nozzle 16. The first rack 11 is slidably connected to the bottom of the top pressure plate 8, and the counterweight 12 is connected to the bottom of the first rack 11. The gear 13 is rotatably connected to the bottom of the pressure plate 8, and the second rack 14 is slidably connected inside the pressure plate 8. The first rack 11 and the second rack 14 are located on both sides of the gear 13, and both the first rack 11 and the second rack 14 mesh with the gear 13. The control valve 15 is installed at the bottom of the second rack 14, and the suction nozzle 16 is connected to the bottom of the control valve 15. A sealing ring is provided at the end of the suction nozzle 16.

[0024] like Figure 4 As shown, it also includes a protective pad 17. The bottom of the counterweight 12 is connected to the protective pad 17, which is made of polyurethane.

[0025] like Figure 4 As shown, it also includes a reset spring 18. The reset spring 18 is provided inside the pressure plate 8. The bottom end of the reset spring 18 is connected to the top of the first rack 11, and the top end of the reset spring 18 is connected inside the pressure plate 8.

[0026] like Figure 3 As shown, it also includes rubber rings 19. Rubber rings 19 are fitted at both ends of the rotating wheel 9. The rubber rings 19 are made of hydrogenated nitrile rubber.

[0027] like Figure 1 As shown, it also includes adjustable feet 20, which are installed at the bottom of the base 1.

[0028] When the drive shaft is inserted, the operator starts the first motor 4. The output shaft of the first motor 4 drives the lead screw 5 to rotate. The lead screw 5 generates axial thrust through its threaded engagement with the fixed plate 2, pushing the moving plate 3 vertically upward along the guide rod 6, thus creating an opening space between the fixed plate 2 and the moving plate 3, which originally formed a partially circular tube structure. At this time, the operator horizontally inserts the drive shaft into the concave arc surface of the fixed plate 2. Subsequently, the first motor 4 rotates in the opposite direction, and the lead screw 5 drives the moving plate 3 to descend vertically along the guide rod 6. The concave arc surface of the moving plate 3 and the fixed plate 2 reclose to form a partially circular tube, and the rubber rings 19 of the surrounding rotating wheels 9 make initial contact with the outer surface of the drive shaft. Then, the electric push rods 7 on the outer sides of the fixed plate 2 and the moving plate 3 are activated simultaneously. The piston rod pushes the pressure plate 8 to move horizontally towards the center of the circular tube. The rotating wheels 9 at the end of the pressure plate 8 elastically compress the outer wall of the drive shaft through the rubber rings 19, completing the clamping and positioning.

[0029] During the downward pressing of the top pressure plate 8, the protective pad 17 at the bottom of the counterweight 12 first contacts the top surface of the drive shaft. As the pressure plate 8 continues to press down, the protective pad 17 deforms, and the deformation force pushes the first rack 11 to slide inward into the pressure plate 8. The return spring 18 is compressed and stores elastic potential energy. When the first rack 11 moves, it drives the meshing gear 13 to rotate. The gear 13 drives the second rack 14 to slide downward. The control valve 15 at the bottom of the second rack 14 descends accordingly. When the suction nozzle 16 at the bottom of the control valve 15 is completely in contact with the top surface of the drive shaft, the external air pump starts to pump air. The suction nozzle 16 forms a negative pressure adsorption with the surface of the drive shaft. At this time, the drive shaft is fixed by the dual action of mechanical compression and vacuum adsorption, and cannot undergo axial or circumferential displacement.

[0030] When the drive shaft position needs adjustment, the external air pump inflates the control valve 15 to release the negative pressure on the suction nozzle 16. Simultaneously, the top electric push rod 7 retracts, pulling the pressure plate 8 upward. The return spring 18 rebounds, and the counterweight 12 and the return spring 18 cooperate to make the first rack 11 slide downward. This, in turn, causes the second rack 14 to slide upward and reset via the gear 13. The protective pad 17 disengages from the top surface of the drive shaft, releasing the displacement restriction on the drive shaft. The electric push rods 7 on both sides push the pressure plate 8 closer to the drive shaft again, causing the rubber ring 19 at the end of the rotating wheel 9 to form a new compression state with the outer wall of the drive shaft. At this time, the second motor 10 starts the rotation of the drive rotating wheel 9, and all rotating wheels 9 maintain the same direction of rotation. The rubber ring 19 undergoes radial deformation under compression, and its rolling is driven by friction with the surface of the drive shaft. The rotating wheels 9 on both sides and at the bottom work together to form a multi-point drive, and the drive shaft moves smoothly along the axial direction. During the movement, the elastic deformation of the rubber ring 19 absorbs local stress and avoids surface scratches.

[0031] The adjustable feet 20 mounted on the bottom of the base 1 can be rotated to adjust the support height, adapting to minor unevenness of the placement surface and ensuring the overall level of the fixture. If relocation is required, the adjustable feet 20 can be replaced with casters with brakes for easy overall movement. Furthermore, the base 1 can be assembled with an external cylinder base frame, enabling axial feed of the fixture system via cylinder drive.

[0032] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the following claims should be given the broadest interpretation in order to cover all variations and equivalent structures and functions.

Claims

1. An adaptive fixture for machining drive shafts, characterized in that: Includes a base (1), a fixed plate (2) connected to the top of the base (1), a movable plate (3) provided on the top of the fixed plate (2), the fixed plate (2) and the movable plate (3) forming a partially round tube, a first motor (4) installed in the middle of the movable plate (3), a lead screw (5) connected to the output shaft of the first motor (4), the lead screw (5) being rotatably connected to the movable plate (3), the lead screw (5) being threadedly connected to the fixed plate (2), and a guide rod connected to the bottom of the movable plate (3). 6) The guide rod (6) is slidably connected to the fixed plate (2). Electric push rods (7) are installed on the outside of both the fixed plate (2) and the moving plate (3). The piston rod of the electric push rod (7) passes through the fixed plate (2) or the moving plate (3) and is connected to a pressure plate (8). A rotating wheel (9) is rotatably connected to one end of the pressure plate (8) facing the center of the circular tube. A second motor (10) is installed on the pressure plate (8). The output shaft of the second motor (10) is connected to the axis of the rotating wheel (9).

2. The adaptive fixture for machining a drive shaft according to claim 1, characterized in that: It also includes, The bottom of the pressure plate (8) at the top is slidably connected to a first rack (11), and the bottom of the first rack (11) is connected to a counterweight (12). The bottom of the pressure plate (8) is rotatably connected to a gear (13), and the inside of the pressure plate (8) is slidably connected to a second rack (14). The first rack (11) and the second rack (14) are respectively located on both sides of the gear (13). The first rack (11) and the second rack (14) are both meshed with the gear (13). A control valve (15) is installed at the bottom of the second rack (14), and a suction nozzle (16) is connected to the bottom of the control valve (15).

3. An adaptive fixture for machining a drive shaft according to claim 2, characterized in that: The bottom of the counterweight (12) is connected to a protective pad (17).

4. An adaptive fixture for machining a drive shaft according to claim 3, characterized in that: A reset spring (18) is provided inside the pressure plate (8). The bottom end of the reset spring (18) is connected to the top of the first rack (11), and the top end of the reset spring (18) is connected inside the pressure plate (8).

5. An adaptive fixture for machining a drive shaft according to claim 4, characterized in that: Rubber rings (19) are fitted at both ends of the rotating wheel (9).

6. An adaptive fixture for machining a drive shaft according to claim 5, characterized in that: The base (1) is equipped with adjustable feet (20) at its bottom.

Images