A size and shape adaptive clamping and position self-holding device

Abstract

The application relates to a size and shape self-adaptive clamping and position self-keeping device, which comprises a plurality of independent rotary clamps, a clamp mounting frame and a clamp self-keeping mechanism, and the clamp self-keeping mechanism is used for providing rotary resistance to the rotary clamp so that the rotary clamp is kept in a current position. The rotary clamp of the application cannot easily change the position under the action of the rotary resistance, and only when the deformation force of a workpiece is greater than the rotary resistance, the rotary clamp is pushed to rotate; once the deformation force disappears, the rotary clamp enters the position keeping state again, and the size and shape of the workpiece can be self-adaptively clamped; the rotary resistance is positively correlated with the clamping force of the rotary clamp on the workpiece, and the clamping force can be adjusted by adjusting the rotary resistance of the clamp self-keeping mechanism, so that the clamping force is not only adjustable and controllable, but also has high stability. The application can reduce the development cycle and cost of the clamp device, and is especially beneficial to the establishment of the clamp circulation and the flow production of the workpiece with the shape changing in the process.

Description

Technical Field

[0001] This application relates to the field of tooling and fixture technology, and in particular to a size and shape adaptive clamping and position self-holding device. Background Technology

[0002] Some metal parts are manufactured through a series of processes such as continuous cold heading, bending, and punching. During the continuous processing, the local size and shape of the parts may change. Since the processing molds used in each processing step are not the same, a clamping device is needed to transfer the semi-finished products from each step to the next step. If the clamping device can clamp the parts even when their size and shape change, a circular automated production line can be built, and the same clamping device can clamp the semi-finished products from different steps.

[0003] For example, Chinese patent application CN106346389A, entitled "A Ring-Shaped Clamping Workpiece," describes a clamping workpiece comprising an outer ring, an inner ring, a drive rod, a driver, a clamping head, and a spring. The driver can move the drive rod, clamping head, and spring axially to clamp the ring-shaped part. Simultaneously, the spring has elastic deformation capability, enabling adaptive clamping of the inner ring-shaped part. However, the spring settings in related prior art are unreasonable, leading to excessive swaying of the clamping head. The clamping force relies solely on the spring's elastic force; the larger the part, the greater the clamping force, and vice versa. This results in large fluctuations in clamping force, poor stability, and an unsatisfactory clamping effect, requiring improvement. Summary of the Invention

[0004] To address the technical problem of existing clamping devices having large variations in clamping force and unsatisfactory clamping effects, this invention provides a size and shape adaptive clamping and position self-holding device.

[0005] The technical solution provided in this application is as follows: a size and shape adaptive clamping and position self-holding device, including multiple independent rotating jaws, a jaw mounting frame and a jaw self-holding mechanism. The multiple rotating jaws are arranged in a ring on the jaw mounting frame for multi-point clamping of the inner workpiece or for multi-point support of the inner wall of the outer workpiece. The jaw self-holding mechanism is used to provide rotational resistance to the rotating jaws so that the rotating jaws are held in the current position.

[0006] By adopting the above technical solution, the rotary gripper of this application cannot easily change position under the action of rotational resistance. The rotary gripper will only be pushed to rotate when the deformation force of the workpiece is greater than the rotational resistance. Once the deformation force disappears, the rotary gripper re-enters the position-holding state. Since multiple rotary grippers are independent and do not affect each other, the position (opening) of each rotary gripper can be inconsistent, enabling adaptive clamping of the workpiece's size and shape. The rotational resistance is positively correlated with the clamping force of the rotary gripper on the workpiece. By adjusting the rotational resistance of the gripper's self-holding mechanism, the clamping force can be adjusted. Therefore, the clamping force is not only adjustable and controllable but also highly stable. This application can reduce the development cycle and cost of fixture devices, and is particularly beneficial for establishing a fixture cycle for streamlined production of workpieces whose shape changes during the manufacturing process.

[0007] Preferably, the gripper self-holding mechanism includes a friction plate and a force-applying element. The force-applying element is used to press the friction plate against the rotating gripper, so that the friction plate contacts the rotating gripper to generate frictional force, thereby preventing the rotating gripper from rotating.

[0008] Preferably, the force-applying element is a power element, which is a cylinder, electric cylinder, hydraulic cylinder or electromagnet, used to apply pressure to the friction plate and release pressure.

[0009] Preferably, the force-applying element is a non-powered element, such as a disc spring, leaf spring, or cylindrical spring; the device further includes a self-holding release mechanism, which is used to push the friction plate away from the rotating jaw, thereby reducing or eliminating the friction between the friction plate and the rotating jaw.

[0010] Preferably, the rotating gripper is further equipped with a reset element, which is used to drive the rotating gripper to reset inward or outward. The reset element is a torsion spring or a torsion bar.

[0011] Preferably, the device further includes a gripper pressing mechanism for driving the rotating gripper to rotate to a designated position.

[0012] Preferably, the gripper pressing and rotating mechanism includes a first driving rod, which is slidably mounted on the gripper mounting bracket. The first driving rod is provided with a first driving inclined surface, and the rotating gripper is provided with a corresponding second driving inclined surface. When the first driving rod presses down, the rotating gripper is driven to rotate to a designated position through the cooperation of the first driving inclined surface and the second driving inclined surface.

[0013] Preferably, the gripper mounting frame is a split structure, including multiple sub-gripper mounting frames, each of which is provided with at least one set of rotating grippers and one set of gripper self-holding mechanisms.

[0014] Preferably, the gripper mounting bracket includes an upper cover plate and a lower cover plate. The upper cover plate has a first clearance hole in the middle, and the lower cover plate has a second clearance hole in the middle. Multiple rotating grippers are rotatably disposed between the upper cover plate and the lower cover plate via a first rotating shaft. A flange is disposed on the first rotating shaft to form the friction plate. The force-applying element is a disc spring, which is disposed between the flange and the gripper mounting bracket to press the flange against the end face of the rotating gripper, so that the rotating gripper generates displacement resistance. The self-holding release mechanism includes a second drive rod, which is used to drive the first rotating shaft to move axially, so that the flange on the first rotating shaft separates from the rotating gripper.

[0015] Preferably, the rotating jaws are provided with an arc-shaped limiting concave surface, and the inner wall of the second clearance hole is provided with an arc-shaped limiting convex surface. The arc-shaped limiting concave surface and the arc-shaped limiting convex surface cooperate to limit the inner and outer rotation points of the rotating jaws. The number of rotating jaws is three to six, and the clamping end of the rotating jaws is arc-shaped.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. Under the action of rotational resistance, the position of the rotary gripper of this application cannot be easily changed, and the rotational resistance is positively correlated with the clamping force of the rotary gripper on the workpiece. By adjusting the rotational resistance of the gripper self-holding mechanism, the clamping force can be adjusted. Therefore, the clamping force is not only adjustable and controllable, but also highly stable. 2. Multiple rotating jaws are independent of each other and do not affect each other. The position (opening) of each rotating jaw can be different, which can adaptively clamp the size and shape of the workpiece. 3. This application can reduce the development cycle and cost of fixture devices, and is particularly beneficial for the establishment of fixture cycles for streamlined production of workpieces whose shape changes during the manufacturing process. Attached Figure Description

[0017] Figure 1 This is a front perspective view of Embodiment 1 of this application; Figure 2 This is a perspective view of the back of Embodiment 1 of this application; Figure 3 This is a top view of Embodiment 1 of this application; Figure 4 This is a bottom view of Embodiment 1 of this application; Figure 5 yes Figure 3 Sectional view along the AA direction; Figure 6 This is an exploded structural diagram of Embodiment 1 of this application; Figure 7 This is a front perspective view of Embodiment 2 of this application; Figure 8This is a perspective view of the back of Embodiment 2 of this application; Figure 9 This is a top view of Embodiment 2 of this application; Figure 10 This is a bottom view of Embodiment 2 of this application; Figure 11 yes Figure 9 Sectional view along the BB direction; Figure 12 This is a partially exploded structural diagram of Embodiment 2 of this application; Figure 13 This is a frontal exploded view of Embodiment 2 of this application; Figure 14 This is an exploded view of the back side of Embodiment 2 of this application; Figure 15 This is an exploded front view of the gripper assembly described in Embodiment 2 of this application; Figure 16 This is an exploded view of the back side of the gripper assembly described in Embodiment 2 of this application; Figure 17 This is a front perspective view of Embodiment 3 of this application; Figure 18 This is a perspective view of the back of Embodiment 3 of this application; Figure 19 This is a schematic diagram of the separated state structure of Embodiment 3 of this application.

[0018] Explanation of reference numerals in the attached drawings: 1. Rotating gripper; 11. Second driving ramp; 12. Arc-shaped limiting concave surface; 2. Gripper mounting bracket; 21. Sub-gripper mounting bracket; 22. Upper cover plate; 221. First clearance hole; 23. Lower cover plate; 231. Second clearance hole; 232. Arc-shaped limiting convex surface; 24. First rotating shaft; 241. Flange; 25. Screw; 3. Gripper self-holding mechanism; 31. Friction plate; 32. Force application element; 4. Reset component; 5. Gripper pressing and rotating mechanism; 51. First driving rod; 511. First driving ramp. Detailed Implementation

[0019] The following is in conjunction with the appendix Figure 1-19 This application will be described in further detail.

[0020] Example 1: Reference Figures 1 to 6 This application discloses a size and shape adaptive clamping and position self-holding device, including multiple independent rotating jaws 1, a jaw mounting frame 2, and a jaw self-holding mechanism 3. The multiple rotating jaws 1 are arranged in a ring on the jaw mounting frame 2 for multi-point clamping of the inner workpiece. The jaw self-holding mechanism 3 is used to provide rotational resistance to the rotating jaws 1 so that the rotating jaws 1 are held in the current position.

[0021] Reference Figure 5 and Figure 6 The gripper self-holding mechanism 3 includes a friction plate 31 and a force-applying element 32. The force-applying element 32 is used to press the friction plate 31 against the rotating gripper 1, so that the friction plate 31 contacts the rotating gripper 1 to generate friction, thereby preventing the rotating gripper 1 from rotating. In this embodiment, the force-applying element 32 is a non-powered element, specifically a disc spring. Of course, other non-powered elements can also be selected, such as leaf springs or cylindrical springs, etc. This embodiment can achieve stable clamping of workpieces of different sizes and shapes, but it is a unidirectional adaptive situation, which can only adapt to the situation where the workpiece size gradually increases, but cannot adapt to the situation where the workpiece size decreases.

[0022] Reference Figure 5 and Figure 6 The gripper mounting bracket 2 includes an upper cover plate 22 and a lower cover plate 23. The upper cover plate 22 has a first clearance hole 221 in the middle, and the lower cover plate 23 has a second clearance hole 231 in the middle. Multiple rotating grippers 1 are rotatably disposed between the upper cover plate 22 and the lower cover plate 23 via a first rotating shaft 24. A flange 241 is disposed on the first rotating shaft 24, forming the friction plate 31. A disc spring is disposed between the flange 241 and the gripper mounting bracket 2 to press the flange 241 against the end face of the rotating gripper 1, thereby generating displacement resistance for the rotating gripper 1. The upper part of the rotating gripper 1 contacts the surface of the flange 241, and the lower part contacts the inner surface of the gripper mounting bracket 2. Relying on the friction generated after pressing, the rotating gripper 1 generates rotational resistance. Without a strong external force, the rotating gripper 1 cannot move, thus forming a self-holding function.

[0023] The upper cover plate 22 and the lower cover plate 23 are provided with round holes, and the upper and lower ends of the first rotating shaft 24 are fixed in the round holes, thereby ensuring that the first rotating shaft 24 does not wobble, the rotating jaw 1 rotates smoothly, has good stability, and has high repeatability of clamping position.

[0024] The first clearance hole 221 and the second clearance hole 231 form a clearance space, facilitating the placement of the workpiece and the entry and exit of processing equipment for processing. The processing equipment here mainly refers to the pressing punch and the pressing base. After the clamping device clamps the workpiece, the pressing punch and the pressing base move up and down, or only the pressing punch moves downward to enter the clamping device for pressing processing of the workpiece. The upper cover plate 22 and the lower cover plate 23 are locked by screws 25, thereby confining the rotating jaw 1, the first rotating shaft 24, the friction plate 31 and the force application element 32 within the jaw mounting frame 2.

[0025] Since the force-applying element 32 in this embodiment uses a disc spring, which is a non-powered element, the disc spring can always press the friction plate 31 against the rotating jaw 1, preventing the rotating jaw 1 from rotating. To reset the rotating jaw 1, a relatively large driving force is required, which causes considerable inconvenience. (Refer to...) Figure 5 To facilitate the resetting of the rotating jaw 1, the device further includes a self-holding release mechanism. This mechanism pushes the friction plate 31 away from the rotating jaw 1, reducing or eliminating the friction between the friction plate 31 and the rotating jaw 1. More specifically, the self-holding release mechanism includes a second drive rod (external, not shown), which drives the first rotating shaft 24 to move axially, thereby separating the flange 241 (i.e., the friction plate 31) on the first rotating shaft 24 from the rotating jaw 1. At this time, the rotating jaw 1 can rotate freely.

[0026] Reference Figure 4 The rotating jaw 1 is provided with an arc-shaped limiting concave surface 12, and the inner wall of the second clearance hole 231 is provided with an arc-shaped limiting convex surface 232. The arc-shaped limiting concave surface 12 and the arc-shaped limiting convex surface 232 cooperate to limit the inner and outer rotational dead points of the rotating jaw 1, that is, to limit the opening and closing stroke of the rotating jaw 1. The number of rotating jaws 1 is three to six, which can be adjusted according to the complexity and size of the workpiece. In this embodiment, four are used. Generally, they are arranged evenly at the included angle, so that the clamping force on the workpiece is more balanced, the workpiece is not easy to shake or tilt, and the clamping is stable. Since each rotating jaw 1 moves independently and does not affect each other, the clamping device of this application can also clamp workpieces with non-circular cross sections. The clamping end of the rotating jaw 1 is arc-shaped, which has good strength and can also fit tightly with the surface of the workpiece to form point contact, resulting in good clamping effect. This application has a simple structure and a relatively small size.

[0027] The rotating jaw 1 of this application cannot easily change position under the action of rotational resistance. It is only pushed to rotate when the deformation force of the workpiece exceeds the rotational resistance. Once the deformation force disappears, the rotating jaw 1 re-enters the position-holding state. Since the multiple rotating jaws 1 are independent and do not affect each other, the position (opening) of each rotating jaw 1 can be inconsistent, enabling adaptive clamping of the workpiece's size and shape. The rotational resistance is positively correlated with the clamping force of the rotating jaw 1 on the workpiece. By adjusting the rotational resistance of the jaw self-holding mechanism 3, the clamping force can be adjusted. Therefore, the clamping force is not only adjustable and controllable but also highly stable. This application can reduce the development cycle and cost of fixture devices, and is particularly beneficial for establishing a fixture cycle for streamlined production of workpieces whose shape changes during the manufacturing process.

[0028] In existing technologies, the clamping force is equal to the spring force, which is constantly changing and directly proportional to the diameter of the clamping position of the semi-finished product. In the initial stages of processing, the diameter of the clamping position is small, resulting in a smaller clamping force and poor clamping stability. This application solves this technical problem. Regardless of the position of the rotating jaw 1, the clamping force remains consistent, independent of the opening of the rotating jaw 1. Therefore, the clamping stability is far superior to that of existing technologies.

[0029] Furthermore, some cold heading processes may cause inconsistent thickening in the radial directions of the workpiece clamping area (irregular upsetting). Traditional adaptive clamping devices lack position-holding functions. Because the elasticity of multiple clamping heads is basically the same, the workpiece tends to automatically center itself (the workpiece position will change secondary after upsetting). Also, because the workpiece clamping area has an irregular cross-section, the clamping point will have a certain deviation, meaning the workpiece position has some uncertainty, causing significant problems for the next process. The rotational resistance described in this application eliminates the tendency for the rotating jaws 1 to automatically center themselves. After the workpiece clamping area is upset, the workpiece position will not change secondary due to the different clamping forces of the multiple rotating jaws 1. Therefore, the workpiece position is definite and will not cause problems for the next process.

[0030] In this application, the force-applying element can also be a power element, such as a cylinder, electric cylinder, hydraulic cylinder, or electromagnet, used to apply pressure to and release pressure on the friction plate 31. By controlling the action of these power elements, pressure can be applied and released freely. Furthermore, the pressure can be adjusted by adjusting the performance parameters of these power elements, thereby adjusting the rotational resistance of the rotating jaw 1, and consequently adjusting the clamping force on the workpiece, making the clamping force variable and controllable.

[0031] In this application, when multiple rotating grippers 1 are arranged in a ring on the gripper mounting frame 2 and facing outwards, the workpiece on the outer side can be held at multiple points on the inner wall, which is another application scenario. However, the implementation principle is the same. At this time, the size of the workpiece clamping part should gradually become thinner, and it can only be unidirectionally adaptive.

[0032] Example 2: Reference Figures 7 to 16 As a second embodiment of this application, the difference from the first embodiment is that the rotating jaw 1 is also equipped with a reset member 4. The reset member 4 is used to drive the rotating jaw 1 to reset inward. The reset member 4 is a torsion spring (or a torsion bar). When the self-holding of the rotating jaw 1 is released, under the action of the reset member 4, the rotating jaw 1 resets inward (rotates to the inner dead point). Therefore, the clamping part of the workpiece can adapt to both thickening and thinning. This embodiment has a bidirectional adaptive function.

[0033] Reference Figure 12 The device further includes a gripper pressing and rotating mechanism 5, used to drive the rotating gripper 1 to rotate to a designated position. Specifically, the gripper pressing and rotating mechanism 5 includes a first drive rod 51, which is slidably mounted on the gripper mounting frame 2. The first drive rod 51 has a first drive inclined surface 511, and the rotating gripper 1 has a corresponding second drive inclined surface 11. When the first drive rod 51 presses down, the rotating gripper 1 is driven to rotate to the designated position through the cooperation of the first drive inclined surface 511 and the second drive inclined surface 11. The gripper pressing and rotating mechanism 5 is used to control the opening degree of the rotating gripper 1, facilitating the picking and placing of workpieces. Since the gripper pressing and rotating mechanism 5 is a forced mechanism with very large force, it can easily overcome the rotational resistance and the reset force of the reset component 4. As long as the driving distance of the first drive rod 51 is controlled, the rotating gripper 1 can reach the corresponding opening degree.

[0034] The other structures and beneficial effects of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0035] Example 3: Reference Figures 17 to 19 As a third embodiment of this application, the difference from the second embodiment is that the gripper mounting frame 2 is a split structure, including multiple sub-gripper mounting frames 21. Each sub-gripper mounting frame 21 is provided with at least one set of rotating grippers 1 and one set of gripper self-holding mechanisms 3. In use, the sub-gripper mounting frames 21 are first separated, and then reassembled when the workpiece arrives to clamp the workpiece, making initial clamping more convenient.

[0036] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A size and shape adaptive clamping and position self-holding device, characterized in that, It includes multiple independent rotating jaws (1), a jaw mounting frame (2), and a jaw self-holding mechanism (3). The multiple rotating jaws (1) are arranged in a ring on the jaw mounting frame (2) for multi-point clamping of the inner workpiece or multi-point support of the inner wall of the outer workpiece. The jaw self-holding mechanism (3) is used to provide rotational resistance to the rotating jaws (1) so that the rotating jaws (1) are held in the current position. The gripper self-holding mechanism (3) includes a friction plate (31) and a force-applying element (32). The force-applying element (32) is used to press the friction plate (31) against the rotating gripper (1) so that the friction plate (31) contacts the rotating gripper (1) to generate frictional force, thereby preventing the rotating gripper (1) from rotating. Among them, the force-applying element (32) is a non-powered element; the size and shape adaptive clamping and position self-holding device also includes a self-holding release mechanism, which is used to push the friction plate (31) away from the rotating jaw (1) so that the friction between the friction plate (31) and the rotating jaw (1) is reduced or eliminated; The gripper mounting bracket (2) includes an upper cover plate (22) and a lower cover plate (23). The upper cover plate (22) has a first clearance hole (221) in the middle, and the lower cover plate (23) has a second clearance hole (231) in the middle. Multiple rotating grippers (1) are rotatably arranged between the upper cover plate (22) and the lower cover plate (23) via a first rotating shaft (24). A flange (241) is provided on the first rotating shaft (24) to form the friction plate (31). The force-applying element (32) is a disc spring, which is arranged between the flange (241) and the gripper mounting bracket (2) to press the flange (241) against the end face of the rotating gripper (1) so that the rotating gripper (1) generates displacement resistance. The self-holding release mechanism includes a second drive rod for driving the first rotating shaft (24) to move axially so that the flange (241) on the first rotating shaft (24) is separated from the rotating gripper (1). The rotating jaw (1) is provided with an arc-shaped limiting concave surface (12), and the inner wall of the second clearance hole (231) is provided with an arc-shaped limiting convex surface (232). The arc-shaped limiting concave surface (12) and the arc-shaped limiting convex surface (232) cooperate to limit the inner and outer rotation points of the rotating jaw (1). The number of rotating jaws (1) is three to six, and the clamping end of the rotating jaw (1) is arc-shaped. Multiple rotating jaws (1) are independent of each other and do not affect each other. The opening position of each rotating jaw (1) may be different, which can adaptively clamp the size and shape of the workpiece; the rotational resistance of the jaw self-holding mechanism (3) is adjustable.

2. The size and shape adaptive clamping and position self-holding device according to claim 1, characterized in that, The rotating gripper (1) is also equipped with a reset member (4), which is used to drive the rotating gripper (1) to reset inward or outward. The reset member (4) is a torsion spring or a torsion bar.

3. The size and shape adaptive clamping and position self-holding device according to claim 1, characterized in that, The device also includes a gripper pressing mechanism (5) for driving the rotating gripper (1) to rotate so that the rotating gripper (1) rotates to a specified position.

4. The size and shape adaptive clamping and position self-holding device according to claim 3, characterized in that, The gripper pressing and rotating mechanism (5) includes a first drive rod (51), which is slidably mounted on the gripper mounting bracket (2). The first drive rod (51) is provided with a first drive inclined surface (511), and the rotating gripper (1) is provided with a corresponding second drive inclined surface (11). When the first drive rod (51) is pressed down, the rotating gripper (1) is driven to rotate to a designated position through the cooperation of the first drive inclined surface (511) and the second drive inclined surface (11).

5. The size and shape adaptive clamping and position self-holding device according to claim 1, characterized in that, The gripper mounting frame (2) is a split structure, including multiple sub-grip mounting frames (21), each sub-grip mounting frame having at least one set of rotating grippers (1) and one set of gripper self-holding mechanisms (3).

Images