A pneumatic polishing fixture for a wheel rim

Abstract

The present application relates to the field of automobile parts processing, especially a pneumatic polishing clamp for wheel rim, aiming at the problems of unstable positioning reference, low clamping efficiency and easy slipping of workpiece of the existing wheel rim polishing clamp, the present application provides the following scheme, which comprises: a mounting assembly comprising a jig bottom plate and a material supporting assembly fixed on the top surface of the jig bottom plate, the material supporting assembly comprises front and rear pressing plates arranged in parallel; a material clamping mechanism is arranged between the front and rear pressing plates, comprising two pressing rods hinged to the top surface of the jig bottom plate and a driving member installed on the top surface of the jig bottom plate for driving the two pressing rods to open and close. The present application realizes fast and stable clamping of wheel rim workpiece by pneumatic driving, effectively prevents workpiece slipping and damage through the cooperation of the pressing mechanism and the anti-skid mechanism, ensures the accessibility and precision of robot polishing, and is suitable for automatic polishing operation of wheel rim casting flash and parting surface.

Description

Technical Field

[0001] This invention relates to the field of automotive parts processing, and more particularly to a pneumatic grinding fixture for wheel rims. Background Technology

[0002] The wheel rim is a key load-bearing and transmission component on the automotive drive axle. Its complex shape typically features an irregular, irregularly shaped outer periphery, a flange plane, and multiple locating bosses. After casting, the burrs on the outer periphery, the parting surface burrs, and the flange periphery flash of the wheel rim need to be ground to ensure the accuracy of subsequent machining and assembly.

[0003] Currently, existing wheel rim grinding fixtures have several shortcomings in practical applications. First, most fixtures use simple planar supports or V-block positioning, failing to fully utilize the structural characteristics of the wheel rim itself. This results in unstable positioning references, poor workpiece consistency after clamping, and consequently affects the repeatability accuracy of the robot's grinding trajectory, easily leading to over-grinding or under-grinding. Second, the clamping operation of the fixtures mostly relies on manual locking or hydraulic drive. Manual methods are inefficient and difficult to match the automated production cycle, while hydraulic systems suffer from high costs and complex maintenance. Furthermore, under clamping force, the workpiece is prone to slippage along inclined surfaces or grooves, leading to positioning failure and further exacerbating the instability of grinding quality. To address these issues, this solution proposes a pneumatic grinding fixture for wheel rims. Summary of the Invention

[0004] The present invention proposes a pneumatic grinding fixture for wheel rims, which solves the problems of unstable positioning reference, low clamping efficiency and easy slippage of workpieces in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A pneumatic grinding fixture for wheel rims, comprising:

[0007] The mounting assembly includes a fixture base plate and a material support assembly fixed to the top surface of the fixture base plate. The material support assembly includes a front pressure plate and a rear pressure plate arranged in parallel.

[0008] The clamping mechanism, located between the front pressure plate and the rear pressure plate, includes two pressure rods hinged to the top surface of the fixture base plate and a driving component installed on the top surface of the fixture base plate for driving the two pressure rods to open and close.

[0009] A clamping mechanism, which is installed at the end of a clamping rod and is used to clamp the workpiece onto the clamping mechanism when the clamping rod is closed;

[0010] An anti-slip mechanism is installed on the pressure mechanism and is used to limit the slippage of the workpiece when the drive element drives the two pressure rods to close.

[0011] A positioning mechanism, which is installed at the front end of the fixture base plate and is used to position the workpiece.

[0012] The above technical solution utilizes the front and rear pressure plates in the material support assembly to form the bottom support reference for the wheel-side workpiece. Combined with the positioning mechanism, the workpiece is quickly initially positioned. Then, the pneumatic drive drives the two pressure rods to close, so that the pressure mechanism presses the workpiece from the side and above. At the same time, the anti-slip mechanism provides additional friction or adsorption force during the clamping process, effectively preventing the workpiece from slipping when under force.

[0013] As a further improvement to the above solution, the pressure rod consists of a clamping rod and a transmission rod fixed to one end of the clamping rod, and the included angle between the clamping rod and the transmission rod is greater than 90° and less than 180°. The driving component includes a cylinder mounted on the top surface of the fixture base plate and a mounting block fixed to the output end of the cylinder. The two ends of the mounting block are respectively hinged to one end of the two transmission rods in the pressure rod. Two connecting blocks are fixed between the front pressure plate and the rear pressure plate. The connection between the clamping rod and the transmission rod of the two pressure rods is respectively hinged to the top surface of the two connecting blocks through connecting rods.

[0014] The above technical solution utilizes the linear reciprocating motion of the cylinder, which is transmitted through the mounting block and connecting rod, to be converted into the opposing or opposing swinging of the ends of the two pressure rods, thereby achieving rapid clamping and loosening. The transmission chain is simple and the response speed is fast.

[0015] As a further improvement to the above solution, the anti-slip mechanism is provided in two sets, and the two sets of anti-slip mechanisms are respectively installed on the front pressure plate and the rear pressure plate. The top of the front pressure plate is provided with a material groove of an isosceles trapezoidal structure that is wider at the top and narrower at the bottom for clamping the workpiece. The structure of the rear pressure plate is the same as that of the front pressure plate.

[0016] Through the above technical solution, the trapezoidal material groove is adapted to the irregular contour of the bottom of the wheel edge, providing preliminary radial limit for the workpiece. Combined with the front and rear anti-slip mechanisms, the workpiece is more stably positioned in the material groove, reducing displacement caused by grinding vibration.

[0017] As a further improvement to the above solution, the anti-slip mechanism includes a first wear-resistant block installed on the inclined side of the material trough of the front or rear pressure plate, and the number of the first wear-resistant blocks on any inclined side is not less than two sets.

[0018] By using the above technical solution, the wear-resistant block is embedded in the inclined edge of the material groove, which increases the friction coefficient of the contact surface between the workpiece and the material groove, thus playing an anti-slip role. On the other hand, the wear-resistant block, as a vulnerable part, can be replaced separately, reducing maintenance costs.

[0019] As a further improvement to the above solution, the anti-slip mechanism includes a hollow pressure pad and an air distribution component for absorbing air from the pressure pad. The horizontal bottom surfaces of the front and rear pressure plates are each provided with a storage groove for accommodating the pressure pad. The top of the pressure pad is inserted into the storage groove and fixed to the bottom surface of the storage groove by a connecting spring. The top surface of the pressure pad has an arc-shaped structure and multiple air suction holes communicating with its interior are provided on the top surface of the pressure pad. A flexible hose communicating with its interior is installed on the bottom surface of the pressure pad for connecting to the air distribution component.

[0020] With the above technical solution, the pressure pad protrudes out of the receiving groove when it is not under force, supported by the connecting spring. When the workpiece is placed in the material groove, the pressure pad is pressed into the receiving groove under the gravity of the workpiece. At the same time, the air distribution component draws air from the inside of the pressure pad through the hose, so that the air suction hole generates negative pressure, thereby firmly adsorbing the bottom surface of the workpiece, significantly improving the anti-slip effect, and the arc-shaped top surface can better fit the curved bottom of the workpiece.

[0021] As a further improvement to the above solution, the air distribution component includes an air cylinder, a rotating shaft, a transmission gear sleeved on the outer circumference of the rotating shaft, and a drive rack fixed on the mounting block by a fixing block. A piston plate is installed inside the air cylinder, and a driven rack is fixed on one side of the piston plate. One end of the driven rack extends to the outside of the air cylinder and meshes with the transmission gear. One end of the rotating shaft is rotatably connected to the outer wall of the front or rear pressure plate near the clamping mechanism. An air supply pipe connected to a flexible hose is installed at the tail of the air cylinder.

[0022] With the above technical solution, when the mounting block moves with the extension and retraction of the cylinder, the active rack drives the transmission gear to rotate, which in turn drives the driven rack and piston plate to reciprocate in the air cylinder, thereby realizing the suction or release of the pressure pad.

[0023] As a further improvement to the above solution, the pressing mechanism includes a fixed pressure plate fixed to the other end of the clamping rod of the pressure rod and a second wear-resistant block fixed to the inner side wall of the fixed pressure plate. The fixed pressure plate is inclined to one side of its inner side wall and fits against the outer circumference of the workpiece after the pressure rod is clamped to the outer circumference of the workpiece, so as to press the workpiece towards the material support assembly.

[0024] With the above technical solution, the fixed pressure plate is set at an angle. When the pressure rod is closed, its inner side wall can naturally fit the outer peripheral curved surface of the wheel edge and provide an axial component force in the direction of the material support assembly, pressing the workpiece downward into the material groove. The structure is simple and reliable.

[0025] As a further improvement to the above solution, the other end of the clamping rod of the pressure rod is provided with an installation groove. The pressing mechanism includes a movable pressure plate, a third wear-resistant block fixed on the inner side wall of the movable pressure plate, a fixed shaft rotatably connected in the installation groove, and a swing arm fixed on the outer periphery of the fixed shaft. One end of the movable pressure plate is fixed to the outer periphery of the fixed shaft through a fixed rod. The swing arm is inclined along the radial direction of the fixed shaft and relative to the clamping rod of the pressure rod. The end of the swing arm away from the fixed shaft extends to the inner side of the pressure rod and drives the fixed shaft to rotate when it touches the outer periphery of the workpiece, so that the movable pressure plate presses the workpiece closer to the material support assembly. A return spring is connected between the outer periphery of the swing arm and the bottom of the installation groove so that the swing arm can automatically return to its original position after losing external force. The end of the swing arm away from the fixed shaft of the pressure rod is a hemispherical structure.

[0026] With the above technical solution, when the pressure bar just begins to close, the movable pressure plate is in a relatively extended state, avoiding interference with the workpiece. When the hemispherical end of the swing arm first contacts the outer periphery of the workpiece, it will be pushed and rotated by the workpiece as the pressure bar continues to clamp, which in turn drives the movable pressure plate to deflect synchronously through the fixed shaft, causing the third wear-resistant block to press against the workpiece surface. The return spring ensures that the movable pressure plate automatically returns to its original position after the clamp is released, facilitating the next clamping.

[0027] As a further improvement to the above solution, the top surface of the fixing block is hinged with a diagonal rod, the bottom of the diagonal rod is fixed with an anti-slip pad, the top surface of the anti-slip pad is higher than the top surface of the pressure pad, and an inclined buffer spring is connected between the outer wall of the diagonal rod and the bottom surface of the fixing block.

[0028] With the above technical solution, during the process of lowering the workpiece into the material trough, the workpiece will first contact the anti-slip pad at the bottom of the inclined rod. Since the anti-slip pad is higher than the pressure pad, the workpiece pushes the inclined rod to rotate around the hinge point, compressing the buffer spring and generating a forward component force that automatically pushes the workpiece forward to the positioning mechanism, thus playing an auxiliary positioning role.

[0029] As a further improvement to the above solution, the positioning mechanism includes a support block installed on the outer wall of the front pressure plate and an auxiliary V-shaped plate that is detachably fixed to the support block by bolts.

[0030] Through the above technical solution, the V-groove on the auxiliary V-plate can lock the cylindrical or conical boss at the front end of the wheel edge, thus achieving precise positioning of the workpiece in the horizontal plane.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. By setting up an installation assembly, clamping mechanism, pressing mechanism, and positioning mechanism, and using a combination of wheel edge bottom plane and flange face for positioning, the positioning datum is stable and reliable, restricting multiple degrees of freedom and ensuring good consistency of workpiece position after clamping. When the robot grinds burrs and parting surfaces, the grinding trajectory has high repeatability, reducing over-grinding and under-grinding problems, ensuring the stability of wheel edge processing dimensions and appearance quality. Moreover, the fixture structure cleverly avoids grinding interference areas, allowing the robot arm to completely traverse the outer periphery of the wheel edge and parting surface without clamping obstruction, ensuring the accessibility of the grinding operation, and is suitable for removing burrs and parting burrs from casting wheel edges.

[0033] 2. Pneumatically driven clamping ensures rapid clamping and releasing. It can be linked with robotic arms and grinding equipment via solenoid valves, perfectly adapting to automated production lines. No manual locking is required, significantly reducing workpiece loading and unloading time and effectively improving the overall grinding production cycle. Furthermore, the pneumatic components are highly standardized, and the fixture positioning surfaces are equipped with detachable wear-resistant inserts. These inserts can be replaced individually after wear, eliminating the need to replace the entire fixture, simplifying maintenance and reducing tooling costs.

[0034] 3. The clamping process is simple, relying on planar references and V-shaped positioning to achieve rapid workpiece alignment. Workers only need to place the workpiece in position to complete precise positioning, requiring low operator skill levels and fundamentally eliminating positional deviations caused by manual clamping and alignment. This results in strong consistency in grinding quality across batches of products. Moreover, the pneumatic clamping force can be steplessly adjusted via a pressure reducing valve. For wheel-side castings, this ensures that the workpiece does not shift or vibrate during grinding, while also preventing damage or deformation of critical positioning surfaces such as flanges and bottom planes due to rigid clamping, effectively protecting the workpiece's critical reference surfaces.

[0035] 4. The fixture's overall structure can directly interface with robotic grinding workstations, featuring standardized interfaces. It can be used with robotic arms for automatic loading and unloading, facilitating integration into automated production lines, reducing the labor intensity of manual grinding, and improving the dusty working environment. Furthermore, by replacing different auxiliary V-plates, it can quickly adapt to various types of wheel-side workpieces, demonstrating good versatility and compatibility.

[0036] 5. The clamping mechanism is designed to press the workpiece towards the support assembly when the clamping rod is clamping its side, preventing the workpiece from loosening or slipping out. The fixed clamping plate has a simple structure and low manufacturing cost; while the movable clamping plate is more flexible. It automatically bends and presses against the workpiece surface after the clamping rod contacts the workpiece, and automatically flattens when the clamping rod opens, resulting in a larger opening diameter and preventing interference when picking up or placing workpieces.

[0037] 6. With the anti-slip mechanism, when fixing the workpiece, the pressure pad first contacts the workpiece surface. At the same time as the cylinder extends and drives the pressure rod to clamp the workpiece, the air in the pressure pad is extracted through the air distribution component, so that the pressure pad is adsorbed on the workpiece surface, effectively preventing the workpiece from sliding during clamping and grinding, and significantly improving the stability of the clamping.

[0038] 7. The positioning mechanism utilizes the V-groove on the auxiliary V-plate to engage the protrusion at the front end of the hub, thereby achieving precise positioning of the workpiece. Simultaneously, the inclined rod and anti-slip pad allow the workpiece to be automatically pushed towards the front pressure plate during the pressing process into the material groove, thus aiding in positioning. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the present invention;

[0040] Figure 2 This is the left view of the present invention;

[0041] Figure 3 This is a front view of the present invention;

[0042] Figure 4 This is a schematic diagram of the auxiliary V-block, wear-resistant block, and material support assembly in Example 1;

[0043] Figure 5 This is a schematic diagram of the pressure rod and cylinder in Example 1;

[0044] Figure 6 This is a schematic diagram of the material support assembly, pressing mechanism, and anti-slip mechanism in Example 2;

[0045] Figure 7 This is a schematic diagram of the clamping mechanism and air distribution components in Example 2;

[0046] Figure 8 This is a schematic diagram of the air distribution component, transmission component, and material pushing assembly in Example 2;

[0047] Figure 9 This is a schematic diagram of the front pressure plate and pressure pad in Example 1;

[0048] Figure 10 This is a schematic diagram of the structure of the pressing mechanism in Example 2 when the movable pressure plate is vertical;

[0049] Figure 11 This is a schematic diagram of the structure of the movable pressure plate of the pressing mechanism in Example 2 when it is bent.

[0050] Explanation of key symbols:

[0051] 1. Fixture base plate; 2. Support block; 3. Auxiliary V-shaped plate; 4. Workpiece; 5. Connecting rod; 6. Pressure rod; 7. Material support mechanism; 8. Front pressure plate; 9. First wear-resistant block; 10. Cylinder; 11. Rear pressure plate; 12. Mounting block; 13. Mounting groove; 14. Suction hole; 15. Pressure pad; 16. Anti-slip pad; 17. Air cylinder; 18. Air supply pipe; 19. Diagonal bar; 20. Driven rack; 21. Rotating shaft; 22. Transmission gear; 23. Driving rack; 24. Storage groove; 25. Hose; 26. Swing arm; 27. Fixed shaft; 28. Connecting block; 29. ​​Fixed block; 701. Fixed pressure plate; 702. Second wear-resistant block; 703. Movable pressure plate; 704. Third wear-resistant block. Detailed Implementation

[0052] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0053] Example 1:

[0054] Please combine Figures 1 to 5 as well as Figure 9 This embodiment provides a pneumatic grinding fixture for wheel rims, including an installation assembly, a clamping mechanism, a pressing mechanism, an anti-slip mechanism, and a positioning mechanism.

[0055] The mounting assembly forms the basis for the entire fixture. It includes a flat fixture base plate 1, on the top surface of which a material support assembly is fixed. The material support assembly consists of a front pressure plate 8 and a rear pressure plate 11 arranged in parallel. Both the front pressure plate 8 and the rear pressure plate 11 are vertically fixed to the fixture base plate 1, with their tops flush, to jointly support the bottom of the workpiece 4. The front pressure plate 8 and the rear pressure plate 11 are fixedly connected by two horizontal connecting blocks 28 to enhance overall rigidity.

[0056] The clamping mechanism is located in the space between the front pressure plate 8 and the rear pressure plate 11. The clamping mechanism includes two pressure rods 6 and a driving component. Each pressure rod 6 is integrally formed or fixedly connected to a clamping rod and a transmission rod fixed to one end of the clamping rod. The angle between the clamping rod and the transmission rod is an obtuse angle, specifically greater than 90° and less than 180°, preferably 120° in this embodiment. The driving component is a cylinder 10, whose cylinder body is fixedly mounted on the top surface of the fixture base plate 1. A mounting block 12 is fixedly connected to the output end of the piston rod of the cylinder 10. Both ends of the mounting block 12 are respectively hinged to the ends of the transmission rods of the two pressure rods 6 via pins. Simultaneously, the bends of the two pressure rods 6 (i.e., the connection points between the clamping rods and the transmission rods) are respectively hinged to the top surface of the corresponding connecting block 28 via a connecting rod 5. Specifically, one end of the connecting rod 5 is rotatably connected to the bend of the pressure rod 6, and the other end is rotatably connected to the hinge seat on the top surface of the connecting block 28. When the piston rod of cylinder 10 retracts, it pushes the mounting block 12 forward. Through the constraint of connecting rod 5, the clamping rod ends of the two pressure rods 6 swing towards each other around the hinge point of their bends, thus achieving closing and clamping. Conversely, when the piston rod extends, the two pressure rods 6 open.

[0057] The pressing mechanism 7 is installed at the end of the clamping rod of the pressing rod 6. For example... Figure 1 and Figure 5 As shown, the pressing mechanism 7 includes a fixed pressure plate 701 and a second wear-resistant block 702. The fixed pressure plate 701 is fixedly connected to the end of the clamping rod, and the plate surface of the fixed pressure plate 701 is inclined at a certain angle relative to the length direction of the clamping rod, specifically inclined inward (i.e. towards the workpiece 4). The second wear-resistant block 702 is fixedly installed on the inner wall of the fixed pressure plate 701 by bolts. When the two pressure rods 6 are closed, the inner wall of the fixed pressure plate 701 is attached to the outer peripheral surface of the workpiece 4 through the second wear-resistant block 702. Due to the inclined setting of the fixed pressure plate 701, while pressing the outer periphery of the workpiece 4, it generates an axial component force pointing towards the bottom of the material support assembly, thereby pressing the workpiece 4 against the top surface of the front pressure plate 8 and the rear pressure plate 11.

[0058] Two sets of anti-slip mechanisms are provided, installed on the front pressure plate 8 and the rear pressure plate 11 respectively. For example... Figure 4 As shown, the top of the front pressure plate 8 has a material groove with a cross-section that is wider at the top and narrower at the bottom, used to clamp the bottom flange of the workpiece 4. The structure of the rear pressure plate 11 is exactly the same as that of the front pressure plate 8, also with a trapezoidal material groove, and the positions of the two are one-to-one. The anti-slip mechanism is specifically a first wear-resistant block 9 embedded on the two inclined sides of the material groove, with no less than two sets of first wear-resistant blocks 9 evenly spaced along the length of the material groove on each inclined side. The first wear-resistant block 9 is made of a high-hardness, high-wear-resistant material (such as tool steel or cemented carbide), and its surface is provided with knurling or anti-slip texture to increase the friction between the contact surface with the workpiece 4 and effectively prevent the workpiece 4 from sliding on the inclined surface.

[0059] The positioning mechanism is installed at the front end of the fixture base plate 1 (i.e., on the side near the front pressure plate 8). The positioning mechanism includes a support block 2 and an auxiliary V-shaped plate 3. The support block 2 is fixed to the outer wall of the front pressure plate 8, and the auxiliary V-shaped plate 3 is detachably fixed to the top surface of the support block 2 by bolts. The front end of the auxiliary V-shaped plate 3 has a V-shaped groove, which is used to hold the cylindrical or conical positioning boss at the front end of the wheel rim workpiece 4, thereby achieving precise positioning of the workpiece 4 in the horizontal front-back direction. For different models of wheel rim workpieces 4, only the auxiliary V-shaped plate 3 with a corresponding V-shaped groove needs to be replaced.

[0060] The implementation principle of this embodiment is as follows: First, according to the model of the wheel edge workpiece 4 to be ground, a suitable auxiliary V-shaped plate 3 is selected and installed on the support block 2. In the initial state, the piston rod of the cylinder 10 is in the retracted state, and the two pressure rods 6 are open. The operator or robot puts the bottom of the workpiece 4 into the trapezoidal groove of the front pressure plate 8 and the rear pressure plate 11, and pushes the workpiece 4 forward so that the front end boss is engaged in the V-groove of the auxiliary V-shaped plate 3, completing the initial positioning. Subsequently, the control system issues a command to extend the piston rod of the cylinder 10 and push the mounting block 12 forward. Under the constraint of the connecting rod 5, the clamping rod ends of the two pressure rods 6 swing towards each other and close. The second wear-resistant block 702 on the fixed pressure plate 701 gradually contacts and presses against the outer circumferential surface of the workpiece 4, while pressing the workpiece 4 downward into the groove. At this time, the bottom of the workpiece 4 is in close contact with the first wear-resistant block 9, forming a stable anti-slip support. The grinding robot grinds the outer circumferential burrs and parting surfaces of the workpiece 4 according to the preset trajectory. After grinding, the piston rod of cylinder 10 retracts, the pressure rod 6 opens, and the operator or robot can remove the workpiece 4.

[0061] Example 2:

[0062] Please combine Figure 1 , Figure 2 , Figure 3 as well as Figures 6 to 11 This embodiment is an improvement on embodiment 1, further described in the following aspects:

[0063] like Figure 10 and Figure 11As shown, a longitudinal mounting groove 13 is provided at the end of the clamping rod of the pressure rod 6. The pressure mechanism 7 includes a movable pressure plate 703, a third wear-resistant block 704, a fixed shaft 27, and a swing arm 26. The fixed shaft 27 is rotatably connected to the upper part of the mounting groove 13, and its axis is perpendicular to the length direction of the clamping rod. One end of the movable pressure plate 703 is fixedly connected to the outer periphery of the fixed shaft 27 by a fixed rod, and the third wear-resistant block 704 is fixed to the inner wall of the other end (i.e., the free end) of the movable pressure plate 703 by bolts. The swing arm 26 is also fixedly connected to the outer periphery of the fixed shaft 27, and the swing arm 26 is set at a certain angle with the movable pressure plate 703. The swing arm 26 extends outward along the radial direction of the fixed shaft 27 and is inclined relative to the length direction of the clamping rod. Its end (the end away from the fixed shaft 27) extends to the inner side of the pressure rod 6 (i.e., the side facing the workpiece 4), and this end is machined into a hemispherical structure to reduce scratches when in contact with the workpiece 4. A return spring (not shown in the figure) is connected between the outer wall of the swing arm 26 and the bottom of the mounting groove 13. In its natural state, the return spring causes the swing arm 26 to open outwards, which in turn drives the movable pressure plate 703 to rotate upwards to a nearly vertical unfolded state via the fixed shaft 27 (e.g., ...). Figure 10 (As shown).

[0064] like Figure 6 and Figure 9 As shown, both the front pressure plate 8 and the rear pressure plate 11 have a receiving groove 24 on their horizontal bottom surfaces (i.e., the flat portion used to support the bottom surface of the workpiece 4). A hollow pressure pad 15 is installed in each receiving groove 24. The pressure pad 15 is made of elastic rubber material, its top inserting into the receiving groove 24, and its top surface is designed with an arc shape to better conform to the irregular curved surface of the workpiece 4's bottom. The bottom surface of the pressure pad 15 is fixedly connected to the bottom surface of the receiving groove 24 via a connecting spring, so that when the workpiece 4 is not placed, the arc-shaped top surface of the pressure pad 15 protrudes from the support plane of the front pressure plate 8 and the rear pressure plate 11. The top surface of the pressure pad 15 has multiple suction holes 14 communicating with its internal cavity, and the bottom surface of the pressure pad 15 is fitted with a flexible hose 25 communicating with its interior, which is used to connect to the air distribution component.

[0065] The air distribution component is used to evacuate or inflate the pressure pad 15. For example... Figure 7 and Figure 8As shown, the air distribution system includes an air cylinder 17, a rotating shaft 21, a transmission gear 22, and a drive rack 23. The air cylinder 17 is fixedly mounted on the side wall of the front pressure plate 8 or the rear pressure plate 11 via a bracket. It has an internal piston plate that divides the air cylinder 17 into a rod chamber and a rodless chamber. A driven rack 20 is fixed to one side of the piston plate, with one end extending from the end cap of the air cylinder 17 and meshing with the transmission gear 22. One end of the rotating shaft 21 is rotatably connected to the outer wall of the front pressure plate 8 (or the rear pressure plate 11) near the clamping mechanism via a bearing seat. The transmission gear 22 is fixedly sleeved on the outer circumference of the rotating shaft 21. The drive rack 23 is fixed to the mounting block 12 via a fixing block 29, and the length direction of the drive rack 23 is parallel to the extension and retraction direction of the cylinder 10. The drive rack 23 meshes with the transmission gear 22. An air supply pipe 18 is installed at the tail end of the rodless chamber of the air cylinder 17. The air supply pipe 18 is connected to the hoses 25 at the bottom of the front and rear pressure pads 15 respectively through a multi-port connector.

[0066] The implementation principle of this embodiment is as follows: After the operator places the workpiece 4 on the front pressure plate 8 and the rear pressure plate 11, the front boss of the auxiliary workpiece 4 is inserted into the V-groove of the auxiliary V-plate 3. At the same time, the bottom of the workpiece 4 presses the pressure pad 15, which protrudes from the support plane, downward into the receiving groove 24, and the connecting spring is compressed. Then, the control system drives the piston rod of the cylinder 10 to extend, and the mounting block 12 moves forward. On the one hand, the pressure rod 6 drives the movable pressure plate 703 to move closer to the workpiece 4; on the other hand, the active rack 23 moves forward with the mounting block 12, driving the transmission gear 22 to rotate, which in turn drives the driven rack 20 and the piston plate to move in the air cylinder 17. The air inside the pressure pad 15 is extracted through the air supply pipe 18 and the hose 25, so that a negative pressure is generated at the air suction hole 14, which firmly adsorbs the bottom surface of the workpiece 4 onto the pressure pad 15. As the pressure rod 6 continues to close, the hemispherical structure at the end of the swing arm 26 first contacts the outer circumference of the workpiece 4. Blocked by the workpiece 4, the swing arm 26 is forced to rotate backward around the fixed shaft 27, stretching the return spring. Simultaneously, the rotation of the swing arm 26 drives the fixed shaft 27 to rotate, thereby driving the movable pressure plate 703 from the unfolded state (…). Figure 10 Rotate towards the side closest to the workpiece until the third wear-resistant block 704 is tightly pressed against the top surface or flange surface of the workpiece 4. Figure 11 This firmly presses workpiece 4 onto the material support assembly. After grinding, the piston rod of cylinder 10 retracts, the driving rack 23 moves in the opposite direction, and drives the piston plate to move in the opposite direction through the transmission gear 22 and the driven rack 20, inflating the pressure pad 15 to release the vacuum adsorption. At the same time, the pressure rod 6 opens, the swing arm 26 returns to its original position under the action of the return spring, and the movable pressure plate 703 rotates, allowing workpiece 4 to be removed.

[0067] Example 3:

[0068] Please combine Figure 7 and Figure 8This embodiment is further improved on the basis of Embodiments 1 and 2 in that:

[0069] A diagonal rod 19 is hinged to the top surface of the fixed block 29 via a hinge seat. An anti-slip pad 16 is fixed to the bottom of the diagonal rod 19, and the top surface of the anti-slip pad 16 is higher than the top surface of the pressure pad 15. An inclined buffer spring is connected between the outer wall of the diagonal rod 19 and the bottom surface of the fixed block 29. When the workpiece 4 is placed downwards, the bottom of the workpiece 4 first contacts and presses down on the anti-slip pad 16 on the diagonal rod 19. The rotation of the diagonal rod 19 generates a forward component force, which helps the front end boss of the workpiece 4 to engage in the V-groove of the auxiliary V-plate 3.

[0070] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A pneumatic grinding fixture for wheel rims, characterized in that, include: The mounting assembly includes a fixture base plate (1) and a material support assembly fixed to the top surface of the fixture base plate (1), the material support assembly including a front pressure plate (8) and a rear pressure plate (11) arranged in parallel. The clamping mechanism is located between the front pressure plate (8) and the rear pressure plate (11), and includes two pressure rods (6) hinged to the top surface of the fixture base plate (1) and a drive member installed on the top surface of the fixture base plate (1) for driving the two pressure rods (6) to open and close. A pressing mechanism (7) is installed at the end of the pressing rod (6) and is used to press the workpiece (4) onto the pressing mechanism when the pressing rod (6) is closed; An anti-slip mechanism is installed on the pressing mechanism and is used to limit the sliding of the workpiece (4) when the driving member drives the two pressing rods (6) to close; The positioning mechanism is installed at the front end of the fixture base plate (1) and is used to position the workpiece (4).

2. The pneumatic grinding fixture for wheel rims according to claim 1, characterized in that, The pressure rod (6) consists of a clamping rod and a transmission rod fixed to one end of the clamping rod, and the angle between the clamping rod and the transmission rod is greater than 90° and less than 180°. The driving component includes a cylinder (10) installed on the top surface of the fixture base plate (1) and a mounting block (12) fixed on the output end of the cylinder (10). The two ends of the mounting block (12) are respectively hinged to one end of the two transmission rods in the pressure rod (6). Two connecting blocks (28) are fixed between the front pressure plate (8) and the rear pressure plate (11). The connection between the clamping rod and the transmission rod of the pressure rod (6) is respectively hinged to the top surface of the two connecting blocks (28) through the connecting rod (5).

3. The pneumatic grinding fixture for wheel rims according to claim 1, characterized in that, The anti-slip mechanism is provided in two sets, and the two sets of suction mechanisms are respectively installed on the front pressure plate (8) and the rear pressure plate (11). The top of the front pressure plate (8) is provided with a material groove with an isosceles trapezoidal structure that is wider at the top and narrower at the bottom for clamping the workpiece (4). The structure of the rear pressure plate (11) is the same as that of the front pressure plate (8).

4. The pneumatic grinding fixture for wheel rims according to claim 3, characterized in that, The anti-slip mechanism includes a first wear-resistant block (9) installed on the inclined side of the material trough of the front pressure plate (8) or the rear pressure plate (11), and the number of the first wear-resistant blocks (9) on any inclined side is not less than two sets.

5. A pneumatic grinding fixture for wheel rims according to claim 3, characterized in that, The anti-slip mechanism includes a hollow pressure pad (15) and an air distribution component for absorbing air from the pressure pad (15). The horizontal bottom surfaces of the front pressure plate (8) and the rear pressure plate (11) are provided with a storage groove (24) for storing the pressure pad (15). The top of the pressure pad (15) is inserted into the storage groove (24) and fixed to the bottom surface of the storage groove (24) by a connecting spring. The top surface of the pressure pad (15) is an arc-shaped structure, and the top surface of the pressure pad (15) is provided with multiple air suction holes (14) communicating with its interior. The bottom surface of the pressure pad (15) is equipped with a flexible hose (25) communicating with its interior for connecting the air distribution component.

6. A pneumatic grinding fixture for wheel rims according to claim 5, characterized in that, The air distribution component includes an air cylinder (17), a rotating shaft (21), a transmission gear (22) sleeved on the outer periphery of the rotating shaft (21), and an active rack (23) fixed on the mounting block (12) by a fixing block (29). A rear piston plate is installed inside the air cylinder (17), and a driven rack (20) is fixed on one side of the piston plate. One end of the driven rack (20) extends to the outside of the air cylinder (17) and meshes with the transmission gear (22). One end of the rotating shaft (21) is rotatably connected to the outer wall of the front pressure plate (8) or the rear pressure plate (11) near the clamping mechanism. An air supply pipe (18) connected to the hose (25) is installed at the tail of the air cylinder (17).

7. A pneumatic grinding fixture for wheel rims according to claim 2, characterized in that, The pressing mechanism (7) includes a fixed pressure plate (701) fixed to the other end of the clamping rod of the pressure rod (6) and a second wear-resistant block (702) fixed on the inner side wall of the fixed pressure plate (701). The fixed pressure plate (701) is inclined to one side of its inner side wall and fits against the outer circumference of the workpiece (4) after the pressure rod (6) is clamped on the outer circumference of the workpiece (4) to press the workpiece (4) towards the material support assembly.

8. A pneumatic grinding fixture for wheel rims according to claim 2, characterized in that, The clamping rod of the pressure rod (6) has an installation groove (13) at the other end. The pressing mechanism (7) includes a movable pressure plate (703), a third wear-resistant block (704) fixed on the inner side wall of the movable pressure plate (703), a fixed shaft (27) rotatably connected in the installation groove (13), and a swing arm (26) fixed on the outer periphery of the fixed shaft (27). One end of the movable pressure plate (703) is fixed to the outer periphery of the fixed shaft (27) through the fixed rod. The swing arm (26) is radially connected to the fixed shaft (27) and is relative to the clamping rod (6). The holding rod is tilted, and the end of the swing arm (26) away from the fixed shaft (27) extends to the inside of the pressure rod (6). When it touches the outer periphery of the workpiece (4), it drives the fixed shaft (27) to rotate so that the movable pressure plate (703) presses the workpiece (4) closer to the material support assembly. A return spring is connected between the outer periphery of the swing arm (26) and the bottom of the mounting groove (13) so that the swing arm (26) can automatically return to its original position after losing external force. The end of the swing arm (26) located away from the fixed shaft (27) of the pressure rod (6) is a hemispherical structure.

9. A pneumatic grinding fixture for wheel rims according to claim 6, characterized in that, The top surface of the fixed block (29) is hinged with a diagonal rod (19), and the bottom of the diagonal rod (19) is fixed with an anti-slip pad (16). The top surface of the anti-slip pad (16) is higher than the top surface of the pressure pad (15). An inclined buffer spring is connected between the outer wall of the diagonal rod (19) and the bottom surface of the fixed block (29).

10. A pneumatic grinding fixture for wheel rims according to claim 1, characterized in that, The positioning mechanism includes a support block (2) installed on the outer wall of the front pressure plate (8) and an auxiliary V-shaped plate (3) that is detachably fixed to the support block (2) by bolts.

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