Three-jaw self-adaptive clamping device for special-shaped workpiece

Abstract

The invention discloses a three-jaw self-adaptive clamping device for a special-shaped workpiece, and belongs to the technical field of machining auxiliary equipment. The three-jaw self-adaptive clamping device comprises a base, three clamping jaws and a driving structure, wherein the three clamping jaws are annularly distributed in the radial direction of the base, and the driving structure is arranged on the base and used for driving the three clamping jaws to move in the radial direction so as to clamp or loosen a workpiece. The three-jaw self-adaptive clamping device further comprises gas-driven self-adaptive structures which are arranged on the sides, close to the workpiece, of the three clamping jaws correspondingly and used for being matched with the surface of the special-shaped workpiece so as to achieve clamping. According to the three-jaw self-adaptive clamping device for the special-shaped workpiece, through an air-driven self-adaptive structure composed of the fixing block, the air cylinder, the telescopic rod, the piston assembly and the reset piece, the surface of the special-shaped workpiece can be efficiently adapted, the problem that a traditional clamping device is poor in adaptability to the special-shaped workpiece is solved, air pressure self-adjustment can be achieved, and the situation that local clamping force is too large is avoided; and deformation of the thin-wall workpiece due to uneven stress is prevented.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of machining auxiliary equipment, and particularly relates to a three-jaw self-adaptive clamping device for special-shaped workpieces. BACKGROUND

[0002] In the industrial fields of machining and assembly, the clamping demand for special-shaped workpieces is increasing, and the clamping stability and workpiece integrity directly determine the subsequent machining precision and product quality.

[0003] At present, the clamping of workpieces in the industry is mainly achieved by using traditional three-jaw chuck devices. The three-jaw chuck device mainly achieves clamping through the synchronous movement of three rigid clamping jaws in the radial direction. The three-jaw chuck device has simple structure and convenient operation, and is widely applied to the clamping of regular cylindrical workpieces and disc-shaped workpieces. However, when the three-jaw chuck device is used for clamping special-shaped workpieces, the clamping surface of the three-jaw chuck device is a rigid plane or an arc surface, and can only form effective adhesion with the surface of a regular workpiece. However, the surface of a special-shaped workpiece has irregular shapes such as concave-convex, inclination and curved surface. Therefore, the clamping jaws can only form local point contact or line contact with the surface of the special-shaped workpiece, and cannot achieve overall adhesion. In addition, the three-jaw chuck device has poor adaptability, and is prone to local clamping force concentration due to the small contact area. Furthermore, due to the inconsistent sizes of different parts of the special-shaped workpiece, the forces borne by different contact points are different when the special-shaped workpiece is clamped. For thin-walled special-shaped workpieces with weak structural strength, the concentrated clamping force of the rigid clamping jaws can easily cause local deformation and indentation of the workpiece, and seriously affect the machining quality.

[0004] Therefore, the three-jaw self-adaptive clamping device for special-shaped workpieces is provided to solve the above problems. SUMMARY

[0005] The three-jaw self-adaptive clamping device for special-shaped workpieces is provided to solve the problems of poor adaptability of the existing three-jaw chuck device to special-shaped workpieces, and local deformation and indentation of thin-walled special-shaped workpieces caused by local clamping force concentration.

[0006] To achieve the above object, the application provides the following technical scheme: a three-jaw self-adaptive clamping device for special-shaped workpieces, comprising a base, three clamping jaws arranged in a ring shape along the radial direction of the base, a driving structure arranged on the base and used for driving the three clamping jaws to move in the radial direction to clamp or release a workpiece, and a gas-driven self-adaptive structure arranged on the side of each clamping jaw close to the workpiece and used for adapting to the surface of the special-shaped workpiece to achieve clamping. The gas-driven self-adaptive structure comprises a fixed block fixedly installed on the claw near the workpiece, a plurality of air cylinders arranged in a rectangular array in the fixed block, a telescopic rod penetrating through the air cylinders and the fixed block in sequence and slidingly connected in the air cylinders and on the fixed block for contacting the workpiece, a piston assembly arranged in the fixed block and connected with the telescopic rod for changing the air pressure in the air cylinders by telescoping of the telescopic rod, and a reset member arranged between the piston assembly and the fixed block for resetting the telescopic rod and the piston assembly when the workpiece is not clamped. The end of the telescopic rod near the workpiece is provided with a universal buffer structure for flexible contact with the surface of the workpiece. The gas-driven self-adaptive structure composed of the fixed block, the air cylinders, the telescopic rod, the piston assembly and the reset member can not only efficiently adapt to the surface of the special-shaped workpiece and solve the poor adaptability of the traditional clamping device to the special-shaped workpiece, but also can avoid excessive local clamping force by air pressure self-regulation, prevent deformation of the thin-walled workpiece due to uneven stress, and increase the contact area with the workpiece and reduce the local pressure by the cooperation of the universal buffer structure and the gas-driven self-adaptive structure, thereby further protecting the thin-walled and easily damaged workpiece from being crushed or deformed during clamping, improving the safety and stability of clamping of the special-shaped thin-walled workpiece, and providing reliable protection for subsequent machining accuracy.

[0007] Preferably, in order to realize stable and accurate radial movement of the claws on the base, the base is provided with a guide groove corresponding to the position of the claws, and the bottom of the claw is slidingly connected in the guide groove. The guide groove provides a specific track for the movement of the claw, limiting the freedom of the claw in other directions except the radial direction. This design ensures that the claw can only move radially along the guide groove under the action of the driving structure, thereby ensuring the stability and accuracy of the movement of the claw and improving the accuracy of the clamping position of the workpiece by the entire clamping device.

[0008] Preferably, in order to drive the three claws to move radially to clamp or release the workpiece, the driving structure comprises a screw rod penetrating through the bottom of each of the three claws and rotatingly connected in the guide groove arranged correspondingly in the base, and the screw rod is screwed with the bottom of the corresponding claw. By rotating the screw rod, the claw will move linearly along the axial direction of the screw rod, i.e. the radial direction of the base, thereby realizing clamping or releasing the workpiece.

[0009] Preferably, in order to adapt to the surface of the special-shaped workpiece and avoid excessive local clamping force, the piston assembly comprises a fixed cylinder fixedly arranged in the fixed block at a position corresponding to the top of the telescopic rod and the air cylinder, a piston slidingly connected in the fixed cylinder, a push rod penetrating the fixed cylinder near the air cylinder and fixedly connected with the piston, a multi-fold frame fixedly connected with the push rod away from the piston, and an air pipe fixedly arranged in the fixed cylinder away from the push rod, the push rod slidingly connected with the fixed cylinder, the multi-fold frame fixedly connected with the telescopic rod away from the air cylinder at the end away from the push rod, and the air pipe fixedly connected with the air cylinder away from the telescopic rod at the end away from the fixed cylinder; when the telescopic rod contacts the surface of the special-shaped workpiece, different amplitudes of telescopic movement will be generated according to the shape of the workpiece surface, driving the multi-fold frame and the push rod to move, and then driving the piston to slide in the fixed cylinder, so as to change the air pressure in the fixed cylinder, and then changing the air pressure in the air cylinder through the air pipe to realize self-adjustment of the air pressure. This design can effectively adapt to the surface of the special-shaped workpiece, avoid excessive local clamping force, prevent deformation of the thin-walled workpiece due to uneven force, and improve the clamping quality and safety of the special-shaped thin-walled workpiece.

[0010] Preferably, in order to automatically reset the telescopic rod and the piston assembly when the workpiece is not clamped, the reset member is a spring, one end of the spring is fixedly connected with the multi-fold frame near the telescopic rod, and the other end of the spring is fixedly connected with the fixed block near the fixed cylinder; by using the elastic property of the spring, when the telescopic rod and the piston assembly are displaced when contacting the workpiece, the spring is stretched to generate elastic force, and when the clamping action is completed, the elastic force of the spring will make the telescopic rod and the piston assembly return to the initial position. This design ensures that the device can quickly return to the initial state after each clamping operation, facilitating the next clamping work, and improving the use efficiency and stability of the device.

[0011] Preferably, in order to buffer the impact force when the telescopic rod contacts the workpiece, the universal buffer structure comprises a universal ball rotatably connected to the telescopic rod near the workpiece, a connecting piece fixedly connected to the universal ball away from the telescopic rod, and a rubber head fixedly sleeved outside the connecting piece for contacting the surface of the workpiece; when the telescopic rod contacts the workpiece, the rubber head first contacts the workpiece and can buffer part of the impact force, and at the same time the universal ball can freely rotate in the groove, so that the rubber head can automatically adjust the angle according to the shape of the workpiece surface to increase the contact area with the workpiece. This design can effectively buffer the contact impact force, reduce the local pressure, further avoid damage to the thin-walled and fragile workpiece during clamping, and thus protect the quality and integrity of the workpiece.

[0012] Preferably, in order to further increase the friction between the rubber head and the surface of the workpiece, and enhance the buffering effect, a plurality of protrusions are uniformly arranged on the surface of the rubber head; the design of the protrusions increases the roughness of the surface of the rubber head, and when the rubber head contacts the surface of the workpiece, the protrusions will sink into the tiny concave-convex parts of the surface of the workpiece, thereby increasing the friction and making the clamping more stable; at the same time, the protrusions can also play a certain buffering role when contacting, dispersing the impact force, and helping to improve the stability and reliability of clamping.

[0013] Preferably, in order to realize the stable rotary connection between the universal ball and the telescopic rod, a groove is arranged on the telescopic rod corresponding to the position of the universal ball, and one half of the volume of the universal ball is rotatably connected in the groove, and the other half is fixedly connected with the connecting piece; the universal ball is partially limited by the groove, which can ensure that the universal ball will not be separated from the telescopic rod during rotation, and at the same time, the universal ball has enough rotating space to realize good connection and flexible rotation with the connecting piece, so that the overall stability and flexibility of the universal buffering structure are ensured, and the universal buffering structure can normally play the roles of buffering and adapting to the shape of the surface of the workpiece.

[0014] The gas-driven self-adapting structure composed of the fixed block, the air cylinder, the telescopic rod, the piston assembly and the reset member of the three-jaw self-adapting clamping device for special-shaped workpieces can not only efficiently adapt to the surface of the special-shaped workpiece and solve the poor adaptability of the traditional clamping device to the special-shaped workpiece, but also can be self-adjusted by air pressure to avoid excessive local clamping force and prevent the deformation of the thin-walled workpiece due to uneven stress; The three-jaw self-adapting clamping device for special-shaped workpieces can buffer the impact force at the moment when the telescopic rod contacts the workpiece by the cooperation of the universal buffering structure and the gas-driven self-adapting structure, utilize the flexible contact characteristics, increase the contact area with the workpiece, reduce the local pressure, further protect the thin-walled and easily-damaged workpiece from being pressed or deformed during clamping, and improve the safety and stability of clamping of the special-shaped thin-walled workpiece, thereby providing reliable guarantee for subsequent machining precision; The three-jaw self-adapting clamping device for special-shaped workpieces increases the roughness of the surface of the rubber head by the design of the protrusions, and when the rubber head contacts the surface of the workpiece, the protrusions will sink into the tiny concave-convex parts of the surface of the workpiece, thereby increasing the friction and making the clamping more stable; at the same time, the protrusions can also play a certain buffering role when contacting, dispersing the impact force, and helping to improve the stability and reliability of clamping. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structural schematic view of a three-jaw self-adapting clamping device for special-shaped workpieces; Figure 2 It is an exploded view structural schematic view of a three-jaw self-adapting clamping device for special-shaped workpieces; Figure 3It is a structure schematic view of a driving structure in a three-jaw self-adapting clamping device for special-shaped workpieces. Figure 4 It is a structure schematic view of a gas-driven self-adapting structure in a three-jaw self-adapting clamping device for special-shaped workpieces. Figure 5 It is a sectional structure schematic view of a gas-driven self-adapting structure in a three-jaw self-adapting clamping device for special-shaped workpieces. Figure 6 It is a sectional structure schematic view of a piston assembly in a three-jaw self-adapting clamping device for special-shaped workpieces. Figure 7 It is a structure schematic view of a universal buffer structure in a three-jaw self-adapting clamping device for special-shaped workpieces.

[0016] In the figure: 1, base; 11, guide groove; 2, clamping jaw; 3, driving structure; 31, screw rod; 4, gas-driven self-adapting structure; 41, fixed block; 42, air cylinder; 43, telescopic rod; 431, recess; 44, piston assembly; 441, fixed cylinder; 442, piston; 443, push rod; 444, multi-fold frame; 445, air pipe; 45, reset member; 451, spring; 5, universal buffer structure; 51, universal ball; 52, connecting piece; 53, rubber head; 531, protrusion. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0018] Embodiment 1 The present embodiment provides a three-jaw self-adapting clamping device for special-shaped workpieces, as shown in Figures 1-7As shown, the three-jaw adaptive clamping device comprises a base 1, three clamping jaws 2 distributed in a ring shape along the radial direction of the base 1, a driving structure 3 arranged on the base 1 for driving the three clamping jaws 2 to move along the radial direction to clamp or release the workpiece, and a gas-driven adaptive structure 4 arranged on the side of each clamping jaw 2 close to the workpiece for adapting to the surface of the special-shaped workpiece to achieve clamping. The gas-driven adaptive structure 4 comprises a fixed block 41 fixedly installed on the side of the clamping jaw 2 close to the workpiece, a plurality of air cylinders 42 arranged in a rectangular array in the fixed block 41, a telescopic rod 43 sequentially penetrating through the air cylinders 42 and the fixed block 41 and slidingly connected in the air cylinders 42 and on the fixed block 41 for contacting the workpiece, a piston assembly 44 arranged in the fixed block 41 and connected with the telescopic rod 43 for extending and retracting with the telescopic rod 43 to change the internal gas pressure of the air cylinders 42, and a reset member 45 arranged between the piston assembly 44 and the fixed block 41 for resetting the telescopic rod 43 and the piston assembly 44 when the workpiece is not clamped. A universal buffer structure 5 is arranged at the end of the telescopic rod 43 close to the workpiece for flexible contact with the surface of the workpiece.

[0019] In use, first, the special-shaped workpiece to be clamped is placed in the central area of the base 1, and then the driving structure 3 is started to drive the three clamping jaws 2 distributed in a ring shape along the radial direction of the base 1 to move along the radial direction towards the workpiece until the universal buffer structure 5 at the end of the telescopic rod 43 in the gas-driven adaptive structure 4 on the side of the clamping jaw 2 close to the workpiece initially contacts the surface of the workpiece. As the driving structure 3 continuously drives the clamping jaws 2 to approach, the concave-convex shape of the surface of the workpiece will cause differential extrusion of the telescopic rods 43 at different positions, causing the telescopic rods 43 to slide and contract along the through holes of the air cylinders 42 and the fixed block 41. Among them, the telescopic rods 43 at the convex parts of the workpiece contract more, and the telescopic rods 43 at the concave parts contract less. As the telescopic rods 43 move towards the inside of the air cylinders 42, the internal volume of the air cylinders 42 gradually decreases, and the internal gas pressure synchronously increases. At this time, the piston assembly 44 connected with the telescopic rod 43 synchronously acts with the extension and retraction of the telescopic rod 43 to suck the excess gas in the air cylinders 42, thereby adjusting the internal gas pressure of the air cylinders 42. Through the self-adjustment of the gas pressure, it can be ensured that each telescopic rod 43 can closely fit the surface of the workpiece, thereby achieving self-adaptive clamping of the special-shaped workpiece. At the same time, the universal buffer structure 5 at the end of the telescopic rod 43 can buffer the impact force at the moment of contact between the telescopic rod 43 and the workpiece through its flexible contact characteristics, and can adaptively adjust with the angle of the surface of the workpiece, thereby further increasing the contact area and reducing the local pressure. When the workpiece is finished processing, the driving structure 3 is started to drive the three clamping jaws 2 to move away from the workpiece along the radial direction. At this time, the reset member 45 between the piston assembly 44 and the fixed block 41 releases the elastic potential energy, which pushes the piston assembly 44 to reset. The piston assembly 44 drives the telescopic rod 43 to slide out along the air cylinders 42 and the fixed block 41, so that the telescopic rod 43 and the piston assembly 44 return to the initial state before clamping the workpiece, thereby completing a clamping operation.

[0020] Wherein, in order to realize the stable and accurate radial movement of the claw 2 on the base 1, the base 1 is provided with a guide groove 11 corresponding to the position of the claw 2, and the bottom of the claw 2 is slidingly connected in the guide groove 11; the guide groove 11 provides a specific track for the movement of the claw 2, and limits the freedom of the claw 2 in other directions except the radial movement, so that the claw 2 can only move linearly along the guide groove 11 under the action of the driving structure 3, thereby ensuring the stability and accuracy of the movement of the claw 2 and improving the accuracy of the clamping device for the clamping position of the workpiece.

[0021] Specifically, the driving structure 3 includes a lead screw 31 penetrating through the bottom of each claw 2 and rotatingly connected in the corresponding guide groove 11, and the lead screw 31 is screwed with the bottom of the corresponding claw 2; When the workpiece needs to be clamped, the lead screw 31 penetrating through the bottom of each claw 2 and rotatingly connected in the corresponding guide groove 11 of the base 1 is rotated by manual or motor driving, and since the lead screw 31 is screwed with the bottom of the corresponding claw 2, the rotational movement of the lead screw 31 is converted into the linear movement of the claw 2 through thread transmission, and under the sliding limiting action of the guide groove 11 on the bottom of the claw 2, the claw 2 can only move in the direction of the extension of the guide groove 11, i.e. the radial direction of the base 1, towards the workpiece, and the three claws 2 are driven synchronously by the lead screw 31 to approach the workpiece at the same speed and stroke, until the air-driven self-adaptive structure 4 contacts and completes the self-adaptive clamping of the workpiece, and when the workpiece needs to be released, the three lead screws 31 are reversely and synchronously rotated by manual or motor driving, and the rotational movement of the lead screw 31 is converted into the linear movement of the claw 2 through thread transmission again, so that the claw 2 moves away from the workpiece along the guide groove 11 until it completely separates from the workpiece.

[0022] Further, the piston assembly 44 includes a fixed cylinder 441 fixedly arranged in the fixed block 41 at a position corresponding to the telescopic rod 43 and above the air cylinder 42, a piston 442 slidingly connected in the fixed cylinder 441, a push rod 443 penetrating through one end of the fixed cylinder 441 close to the air cylinder 42 and fixedly connected with the piston 442, a multi-fold frame 444 fixedly connected with the push rod 443 away from the piston 442, and an air pipe 445 fixedly arranged in the fixed cylinder 441 away from the push rod 443, the push rod 443 is slidingly connected on the fixed cylinder 441, one end of the multi-fold frame 444 away from the push rod 443 is fixedly connected with the side edge of one end of the telescopic rod 43 away from the air cylinder 42, and one end of the air pipe 445 away from the fixed cylinder 441 is fixedly connected with one end of the air cylinder 42 away from the telescopic rod 43; When the universal buffer structure 5 at the end of the telescopic rod 43 in the gas-driven self-adaptive structure 4 contacts the surface of the special-shaped workpiece, due to the different concave-convex shapes of the workpiece surface, the telescopic rods 43 at different positions will produce different amplitude of telescopic movement in the corresponding air cylinders 42. Among them, the telescopic rod 43 at the convex part of the workpiece moves more towards the inside of the air cylinder 42, and the telescopic rod 43 at the concave part of the workpiece moves less towards the inside of the air cylinder 42. With the movement of the telescopic rod 43 towards the inside of the air cylinder 42, the internal volume of the air cylinder 42 gradually becomes smaller, and the internal pressure synchronously becomes larger. At the same time, the movement of the telescopic rod 43 will drive the multi-fold frame 444 fixedly connected to the side away from the air cylinder 42 at one end of the telescopic rod 43. The multi-fold frame 444 moves synchronously with the movement direction of the telescopic rod 43, thereby pulling the push rod 443 fixedly connected to the end away from the telescopic rod 43. Since the push rod 443 penetrates the fixed cylinder 441 close to the end of the air cylinder 42 and is slidingly connected to the fixed cylinder 441, the push rod 443 slides along the fixed cylinder 441 in the axial direction under the pulling of the multi-fold frame 444. Since the push rod 443 is fixedly connected to the piston 442 slidingly connected in the fixed cylinder 441, the piston 442 slides away from the air pipe 445 at one end of the fixed cylinder 441 synchronously with the push rod 443. However, with the sliding of the piston 442, the internal volume of the fixed cylinder 441 gradually becomes larger, and the internal pressure synchronously becomes smaller and generates negative pressure. At this time, under the action of the negative pressure in the fixed cylinder 441, the gas in the air cylinder 42 with the pressure increasing due to the volume becoming smaller is sucked into the fixed cylinder 441 through the air pipe 445 fixedly connected between the end of the fixed cylinder 441 away from the push rod 443 and the end of the air cylinder 42 away from the telescopic rod 43, thereby adjusting the gas pressure in the air cylinder 42. Finally, the telescopic rods 43 with different telescopic amplitudes adjust the gas pressure in the corresponding air cylinders 42 through the above linkage, thereby realizing the self-adaptive adjustment of the clamping gas pressure of each telescopic rod 43 according to the shape of the workpiece surface.

[0023] Further, the reset member 45 is a spring 451, one end of the spring 451 is fixedly connected to the side of the multi-fold frame 444 close to the telescopic rod 43, and the other end of the spring 451 is fixedly connected to the inside of the fixed block 41 close to the fixed cylinder 441; When the three-jaw self-adapting clamping device is not clamping the workpiece, the spring 451 is in a compressed state. When the driving structure 3 drives the clamping jaw 2 to approach the workpiece, the telescopic rod 43 in the air-driven self-adapting structure 4 is extruded by the workpiece and slides to contract along the air cylinder 42 and the fixed block 41, and the multi-fold frame 444 fixedly connected to the side edge of the end of the telescopic rod 43 away from the air cylinder 42 moves synchronously with the telescopic rod 43 to the direction of approaching the inside of the fixed block 41. Since one end of the spring 451 is fixedly connected to the side of the multi-fold frame 444 close to the telescopic rod 43, and the other end is fixedly connected to the inside of the side of the fixed cylinder 441 close to the fixed block 41, the movement of the multi-fold frame 444 will stretch the spring 451, so that the spring 451 stores elastic potential energy. At this time, the spring 451 is in a deformed state. When the workpiece processing is completed, the driving structure 3 drives the clamping jaw 2 to move away from the workpiece, and the extrusion force of the workpiece on the telescopic rod 43 disappears. The spring 451 releases the stored elastic potential energy and generates a reverse thrust acting on the multi-fold frame 444, pushing the multi-fold frame 444 to reset in the direction away from the inside of the fixed block 41. In the resetting process of the multi-fold frame 444, it will synchronously drive the push rod 443 and the piston 442 fixedly connected thereto to slide and reset along the fixed cylinder 441, so that the air pressure in the fixed cylinder 441 and the air cylinder 42 returns to the initial state. At the same time, the multi-fold frame 444 also pulls the telescopic rod 43 to slide out along the air cylinder 42 and the fixed block 41, until the telescopic rod 43 and the piston assembly 44 all return to the initial positions when the workpiece is not clamped, ready for the next clamping operation.

[0024] Further, the universal buffer structure 5 includes a universal ball 51 rotatably connected to the end of the telescopic rod 43 close to the workpiece, a connecting piece 52 fixedly connected to the side of the universal ball 51 away from the telescopic rod 43, and a rubber head 53 fixedly sleeved outside the connecting piece 52 for contacting the surface of the workpiece. The telescopic rod 43 is provided with a groove 431 corresponding to the position of the universal ball 51, and half of the volume of the universal ball 51 is rotatably connected in the groove 431, and the other half is fixedly connected with the connecting piece 52. When the telescopic rod 43 of the three-jaw self-adapting clamping device approaches the surface of the special-shaped workpiece, since the recess 431 is formed at the end of the telescopic rod 43 approaching the workpiece and the universal ball 51 is rotatably connected in the recess 431 by half of its volume, the universal ball 51 can rotate flexibly, and the connecting piece 52 connected to the other half of the volume of the universal ball 51 and the rubber head 53 fixedly connected to the outer side of the connecting piece 52 will first contact the surface of the workpiece. The flexible material of the rubber head 53 can first absorb the impact force in the instant of contact between the telescopic rod 43 and the workpiece, so as to avoid rigid collision and damage to the workpiece. However, during the contact process, with the change of the shape of the surface of the workpiece, the universal ball 51 rotates by a corresponding angle in the recess 431, and simultaneously drives the connecting piece 52 and the rubber head 53 to adjust the direction, so that the rubber head 53 can always closely fit the surface of the workpiece, realizes flexible contact, further increases the contact area with the workpiece, and reduces the local pressure. The recess 431 can form a semi-wrapping limiting for the universal ball 51, which not only prevents the universal ball 51 from being separated from the telescopic rod 43 during rotation, but also reserves enough rotating space for the universal ball 51, so as to ensure the flexibility of angle adjustment. In addition, the elasticity of the rubber head 53 itself can also play a buffering role, so as to avoid damage to the surface of the workpiece.

[0025] Example 2 Different from example 1, as shown in FIG. 2, in order to further increase the friction force between the rubber head 53 and the surface of the workpiece and enhance the buffering effect, a plurality of protrusions 531 are uniformly arranged on the surface of the rubber head 53. Figures 4-7 The design of the protrusions 531 increases the roughness of the surface of the rubber head 53. When the rubber head 53 contacts the surface of the workpiece, the protrusions 531 will sink into the small concave-convex parts on the surface of the workpiece, so as to increase the friction force and make the clamping more stable. At the same time, the protrusions 531 can also play a certain buffering role when contacting, so as to disperse the impact force and help to improve the stability and reliability of the clamping.

[0026] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacement or change according to the technical solution and concept of the present application within the technical range disclosed in the present application, which should be covered in the protection scope of the present application.

Claims

1. A three-jaw self-adapting clamping device for special-shaped workpieces, comprising a base (1), three clamping jaws (2) arranged in a ring shape along the radial direction of the base (1), and a driving structure (3) arranged on the base (1) and used to drive the three clamping jaws (2) to move along the radial direction so as to clamp or release the workpiece, characterized in that: The three-jaw self-adapting clamping device further comprises gas-driven self-adapting structures (4) respectively arranged on the three clamping jaws (2) near the workpiece side for adapting to the surface of special-shaped workpieces to realize clamping; ​ The gas-driven self-adapting structure (4) comprises a fixed block (41) fixedly installed on the clamping jaw (2) near the workpiece side, gas cylinders (42) fixedly arranged in the fixed block (41) and arranged in a rectangular array, a telescopic rod (43) sequentially penetrating through the gas cylinders (42) and the fixed block (41) and slidingly connected in the gas cylinders (42) and on the fixed block (41) for contacting the workpiece, a piston assembly (44) arranged in the fixed block (41) and connected with the telescopic rod (43) for extending and retracting with the telescopic rod (43) to change the internal gas pressure of the gas cylinders (42), and a reset member (45) arranged between the piston assembly (44) and the fixed block (41) for resetting the telescopic rod (43) and the piston assembly (44) when the workpiece is not clamped. A universal buffer structure (5) is arranged on the end of the telescopic rod (43) near the workpiece for flexible contact with the surface of the workpiece.

2. The three-jaw self-adapting clamping device for special-shaped workpieces according to claim 1, characterized in that: The base (1) is provided with guide grooves (11) corresponding to the positions of the clamping jaws (2), and the bottom of the clamping jaw (2) is slidingly connected in the guide groove (11).

3. The three-jaw self-adapting clamping device for special-shaped workpieces according to claim 2, characterized in that: The driving structure (3) comprises lead screws (31) respectively penetrating through the bottom of the three clamping jaws (2) and rotationally connected in the guide grooves (11) corresponding to the bottom of the clamping jaws (2).

4. The three-jaw self-adapting clamp device for special-shaped workpieces according to claim 1, characterized in that: The piston assembly (44) comprises a fixed cylinder (441) fixedly arranged in the fixed block (41) corresponding to the position above the telescopic rod (43) and the gas cylinder (42), a piston (442) slidingly connected in the fixed cylinder (441), a push rod (443) penetrating through the end of the fixed cylinder (441) near the gas cylinder (42) and fixedly connected with the piston (442), a multi-fold frame (444) fixedly connected with the end of the push rod (443) away from the piston (442), and a gas pipe (445) fixedly arranged at the end of the fixed cylinder (441) away from the push rod (443), the push rod (443) is slidingly connected on the fixed cylinder (441), the end of the multi-fold frame (444) away from the push rod (443) is fixedly connected with the end of the telescopic rod (43) away from the gas cylinder (42), and the end of the gas pipe (445) away from the fixed cylinder (441) is fixedly connected with the end of the gas cylinder (42) away from the telescopic rod (43).

5. The three-jaw self-adapting clamp device for special-shaped workpieces according to claim 4, characterized in that: The reset member (45) is a spring (451), one end of the spring (451) is fixedly connected with the side of the multi-fold frame (444) near the telescopic rod (43), and the other end of the spring (451) is fixedly connected with the inside of the fixed block (41) near the fixed cylinder (441).

6. The three-jaw self-adapting clamp device for special-shaped workpieces according to claim 1, characterized in that: The universal buffering structure (5) comprises a universal ball (51) rotatably connected to one end of the telescopic rod (43) close to the workpiece, a connecting piece (52) fixedly connected to one side of the universal ball (51) away from the telescopic rod (43), and a rubber head (53) fixedly sleeved outside the connecting piece (52) and used for contacting the surface of the workpiece.

7. The three-jaw self-adapting clamp device for special-shaped workpieces according to claim 6, characterized in that: The rubber head (53) is provided with a plurality of uniformly distributed protrusions (531) on the surface.

8. The three-jaw self-adapting clamp device for special-shaped workpieces according to claim 6, characterized in that: The telescopic rod (43) is provided with a groove (431) corresponding to the position of the universal ball (51), and one half of the volume of the universal ball (51) is rotatably connected in the groove (431), and the other half of the volume is fixedly connected with the connecting piece (52).

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