A workpiece turning and grasping system and method

Abstract

The present invention discloses a workpiece turning and grasping system and method, which relates to workpiece grasping technology, including a mechanical arm, a strip sliding body is fixed at the front end of the mechanical arm, two grasping claws are slidably installed on the strip sliding body, and a driving unit is also arranged in the strip sliding body; the driving unit drives the two grasping claws to move relative to each other to adjust the distance between the two grasping claws; the present invention provides a workpiece turning and grasping system and method, the strip sliding body is used to limit the movement of the grasping claws, so that the two grasping claws can only move along a specific direction, the grasping claws are used to grasp the workpiece, and the driving unit is used to control the two grasping claws to move relative to each other, when encountering a longer workpiece, the two grasping claws can be controlled by the driving unit to move away from each other so as to grasp the two ends of the longer workpiece, which is convenient for the mechanical arm to move the workpiece position, reduces the concentrated load of the mechanical arm, and can also avoid damage to the workpiece surface.

Description

Technical Field

[0001] The invention relates to a workpiece grasping technology, and in particular to a workpiece turning grasping system and method. Background Art

[0002] Turning refers to the process of machining a rotating workpiece through a lathe. However, the machining of a workpiece often requires multiple processes to complete. Therefore, whether transferring the workpiece to the turning processing position or transferring the turned workpiece to other locations, a workpiece grasping robot arm is required to grasp and transfer the workpiece. The main function of the workpiece grasping robot arm is to complete the grasping, handling and placement of various workpieces, providing people with efficient and precise automated operations.

[0003] For example, the patent with the authorization announcement number CN117645148B and the authorization announcement date April 2, 2024, and the name of the patent is a flip-type grasping robot arm, which relates to the field of robot arm technology. This flip-type grasping robot arm includes a base and a robot arm arranged on the base, and the driving end of the robot arm is connected to a mounting plate through a flip assembly, and the flip assembly includes a flip shaft rotatably connected to the driving end of the robot arm, and one end of the flip shaft is fixed to the upper end of the mounting plate. In the process of grasping the shaft workpiece, when the grasped shaft workpiece is tilted due to the center of gravity offset, the support rod on the support assembly on the other side of the tilting direction is driven to move downward and support and push the tilted shaft workpiece to reset and rotate to a horizontal state, which can effectively grasp and flip the workpiece, and also support the tilted shaft workpiece, ensuring the state of the shaft workpiece while avoiding uneven force on the clamping assembly during the clamping process, so as to facilitate the clamping of the workpiece by the robot arm.

[0004] Another example is the patent with the authorization announcement number CN221021056U and the authorization announcement date May 28, 2024, entitled "A workpiece grasping mechanical arm", which includes an arm body and a grasping mechanism. The arm body: a single-chip microcomputer is provided in the middle of the rear end of the upper surface of the bottom plate, a motor 1 is provided in the middle of the front wall of the front frame of the arm body through a mounting seat 1, and the front end of the output shaft of the motor 1 passes through a through hole provided in the middle of the front surface of the front frame of the arm body and extends to the outside; the grasping mechanism: includes a mounting shell, a mounting seat, a swing plate and a grasping hand, and the mounting shell is provided at the front end of the output shaft of the motor 1. This kind of workpiece grasping mechanical arm, through the single-chip microcomputer to control the operation of the motor 2, can firmly grasp the workpiece while avoiding the workpiece grasping mechanical arm from causing damage to the workpiece due to excessive grasping force, so that the workpiece grasping mechanical arm can be quickly adjusted according to the actual situation of different workpieces, and can select a grasping hand matching the workpiece for installation, which greatly increases the scope of application of the workpiece grasping mechanical arm.

[0005] The shortcoming of the prior art is that the grasping structure at the front end of the workpiece grasping robot arm is generally an openable and closable mechanical claw, and the position of the mechanical claw is relatively fixed. In order to ensure the stability of the workpiece during transfer, the mechanical claw is usually made to grasp the middle position of the workpiece. However, for longer workpieces, grasping the middle position of the workpiece not only increases the concentrated load of the workpiece grasping robot arm, but also requires the mechanical claw to strengthen the grasping force of the middle position of the workpiece, which will inevitably cause damage to the surface of the workpiece. Summary of the invention

[0006] The object of the present invention is to provide a workpiece turning grasping system and method to solve the above-mentioned deficiencies in the prior art.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A workpiece turning and grasping system, comprising a mechanical arm, a strip-shaped sliding body is fixed to the front end of the mechanical arm, two grasping claws are slidably mounted on the strip-shaped sliding body, and a driving unit is also arranged in the strip-shaped sliding body;

[0009] The driving unit drives the two grasping claws to move relative to each other to adjust the distance between the two grasping claws;

[0010] The grabbing claw comprises two gripping assemblies and a power unit for driving the two gripping assemblies to move relative to each other;

[0011] The power unit includes a limiting portion fixed to an end of the slider away from the mechanical arm, a sliding groove is provided at one end of the limiting portion away from the strip sliding body, a second bidirectional lead screw is rotatably installed in the sliding groove, one end of the clamping assembly located in the sliding groove is threadedly connected to the second bidirectional lead screw, the two clamping assemblies are symmetrically arranged, a driving motor is also fixedly connected to the limiting portion, and the output shaft of the driving motor is connected to the end of the second bidirectional lead screw;

[0012] The clamping assembly comprises a clamping part threadedly connected to the second bidirectional lead screw, the lower end of the clamping part is rotatably connected to a pressing part via a rotating shaft, and a torsion spring is further connected between the pressing part and the clamping part;

[0013] An elastic pre-stress rod is slidably provided on the clamping part, a pre-stress spring is connected between the elastic pre-stress rod and the clamping part, a connecting rope is wound on the rotating shaft, and a movable end of the connecting rope movably passes through the clamping part and is connected to the elastic pre-stress rod.

[0014] In the above-mentioned turning and grasping system for a workpiece, a working cavity is opened in the strip-shaped sliding body, two sliding blocks are slidably installed in the working cavity, one end of the sliding block extends outside the working cavity, and the two grasping claws are respectively installed at one end of the two sliding blocks located outside the working cavity.

[0015] In the above-mentioned turning and grasping system for a workpiece, the driving unit includes a first bidirectional lead screw rotatably installed in a working chamber, the slider is threadedly connected to the first bidirectional lead screw, the two sliders are symmetrically arranged, and a servo motor is also installed on the outer wall of the strip-shaped sliding body, and the output shaft of the servo motor is fixedly connected to the end of the first bidirectional lead screw.

[0016] In the above-mentioned workpiece turning gripping system, the clamping portion is a square plate-shaped structure, and the extending direction of the clamping portion is perpendicular to the axis of the second bidirectional lead screw.

[0017] In the above-mentioned turning and gripping system for a workpiece, the end of the pressing portion away from the clamping portion is inclined in a direction of approaching each other.

[0018] A method for turning and grasping a workpiece, based on the turning and grasping system of the workpiece, comprises the following steps:

[0019] The robot arm drives the strip-shaped sliding body to move above the workpiece, drives the two grasping claws to move away from each other through the driving unit to expand the distance between the two grasping claws, and then grasps the two ends of the workpiece through the grasping claws.

[0020] In the above technical scheme, the present invention provides a turning and grasping system and method for a workpiece, including a strip-shaped sliding body, a grasping claw and a driving unit. The strip-shaped sliding body is used to limit the movement of the grasping claw so that the two grasping claws can only move in a specific direction. The grasping claws are used to grasp the workpiece, and the driving unit is used to control the two grasping claws to move relative to each other. When encountering a longer workpiece, the two grasping claws can be controlled by the driving unit to move apart so as to grasp the two ends of the longer workpiece, which facilitates the robot arm to move the workpiece position, reduces the concentrated load of the robot arm, and avoids damage to the workpiece surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 A schematic diagram of the three-dimensional structure of a turning and gripping system for a workpiece provided in one embodiment of the present invention.

[0023] Figure 2 A partial cross-sectional view of a turning gripping system for a workpiece provided in accordance with an embodiment of the present invention.

[0024] Figure 3A cross-sectional view of a grabbing claw according to another embodiment of the present invention.

[0025] Figure 4 A cross-sectional view of a grabbing claw according to yet another embodiment of the present invention.

[0026] Figure 5 A cross-sectional view of a grabbing claw provided in accordance with another embodiment of the present invention.

[0027] Figure 6 A schematic diagram of the three-dimensional structure of a clamping portion provided in yet another embodiment of the present invention.

[0028] Figure 7 A partial cross-sectional view of a moving block provided in yet another embodiment of the present invention.

[0029] Figure 8 A cross-sectional view of a grabbing claw provided in accordance with another embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 1. Strip sliding body; 11. Working chamber; 12. Sliding block; 2. Grabbing claw; 21. Driving unit; 211. First bidirectional lead screw; 212. Servo motor; 22. Clamping assembly; 221. Clamping part; 222. Rotating shaft; 223. Pressing part; 224. Elastic pre-stressing rod; 225. Pre-stressing spring; 226. Connecting rope; 23. Power unit; 231. Limiting part; 232. Sliding groove; 233. Second bidirectional lead screw; 234. Driving motor; 24. Pressing unit; 241. Square groove; 242. Driving lead screw; 243. Driven gear; 244. Driving rack; 245. Moving block; 246. Arc surface; 247. Threaded rod. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] like Figure 1-8 As shown, a turning and grasping system for a workpiece provided by an embodiment of the present invention includes a robotic arm, a bar-shaped sliding body 1 is fixed at the front end of the robotic arm, two grasping claws 2 are slidably mounted on the bar-shaped sliding body 1, and a driving unit 21 is also arranged in the bar-shaped sliding body 1; the driving unit 21 drives the two grasping claws 2 to move relative to each other to adjust the distance between the two grasping claws 2.

[0034] Specifically in the present embodiment, the workpieces targeted by the present embodiment are all shaft parts, that is, cylindrical parts. The mechanical arm is a prior art and will not be described in detail. The strip sliding body 1 is a strip structure, in which a cavity is arranged to limit the movement of the grabbing claw 2; the grabbing claw 2 is a mechanical clamping claw with an independent power source; the distance between the two grabbing claws 2 is defined as the clamping distance, and the clamping distance can be adjusted by the driving unit 21 to adapt to workpieces of different lengths. The initial state of the grabbing claw 2 is an open state, and the connection between the front end of the mechanical arm and the strip sliding body 1 is defined as a connection point. When grabbing, the connection point needs to correspond to the midpoint of the axis of the workpiece (and preferably located in the same vertical plane), and the midpoint of the clamping distance also corresponds to the connection point. That is to say, the two grabbing claws 2 are symmetrically distributed with the connection point as the center, and when the driving unit 21 drives the two grabbing claws 2 to move relative to each other, the two grabbing claws 2 are also in the process of movement. Real-time symmetry is to ensure that the two grabbing claws 2 can be symmetrically distributed with the connection point as the center after stopping movement, so that the two grabbing claws 2 can symmetrically clamp the two ends of the workpiece, thereby increasing the stability of the workpiece when it moves; specifically, during operation, the strip sliding body 1 is driven by the robotic arm to move above the workpiece. At this time, the open grabbing claws 2 are located on the outside of the workpiece, and then the two grabbing claws 2 are driven by the driving unit 21 to move relative to each other to move to the two ends of the workpiece, and then the outer wall of the workpiece is symmetrically clamped by the grabbing claws 2, and finally the grabbing claws 2 and the workpiece are driven by the robotic arm to move to the next working position or collection position; in this way, when encountering a longer workpiece, the driving unit 21 can be used to control the two grabbing claws 2 to move away from each other to grab the two ends of the longer workpiece, so as to facilitate the robotic arm to move the workpiece position, reduce the concentrated load of the robotic arm, and avoid damage to the workpiece surface due to excessive grabbing force.

[0035] In the prior art, the grabbing claw 2 generally adopts an arc-shaped grabbing structure and cooperates with rotation to achieve the grabbing of the workpiece. However, this grabbing method is defective. The front end of the arc-shaped grabbing structure (the end close to the workpiece) actually performs a circular motion. When grabbing a workpiece with a larger diameter, the rotation range of the arc-shaped grabbing structure is limited and it cannot extend itself, so it is difficult to grab a workpiece with a larger diameter. When grabbing a workpiece with a smaller diameter (taking the workpiece placed on a certain horizontal plane as an example), since the front end of the arc-shaped grabbing structure performs a circular motion, it is very easy to fail to grab the workpiece. Moreover, since the workpiece has a small diameter, in order to completely grab the workpiece, the arc-shaped grabbing structure needs to rotate excessively, and excessive rotation will cause motion interference (such as the arc-shaped grabbing structures contacting each other or the arc-shaped grabbing structure contacting the robot arm), thereby limiting the movement of the arc-shaped grabbing structure, which will make the arc-shaped grabbing structure unable to completely grab the workpiece. Overall, it is difficult to better grasp the workpiece in the prior art. To achieve a single grasping claw 2 grasping a shaft with a larger diameter range; to this end, the present invention provides another embodiment to simulate the arc grasping structure in the prior art and solve the above-mentioned problem. The grasping claw 2 includes two clamping components 22 and a power unit 23 that drives the two clamping components 22 to move relative to each other. The initial spacing between the two clamping components 22 is the maximum spacing. Different from the mechanical clamps in the prior art, the clamping components 22 in this embodiment can slide relative to each other. The sliding direction of the clamping components 22 is parallel to the extension of the strip sliding body 1 in the width direction. In this way, the power unit 23 drives the clamping components 22 away from each other to expand the diameter range of the workpiece that can be grasped. When the clamping components 22 slide close to each other, the bottom of the clamping component 22 can slide on a horizontal plane, so that the outer wall of the workpiece with a smaller diameter can be directly clamped, and the situation of failing to grasp the workpiece will not occur, and there will be no motion interference.

[0036] The power unit 23 includes a limiting portion 231 fixed to an end of the slider 12 away from the mechanical arm, and a sliding groove 232 is opened at the end of the limiting portion 231 away from the strip sliding body 1, and a second bidirectional lead screw 233 is rotatably installed in the sliding groove 232, and one end of the clamping assembly 22 located in the sliding groove 232 is threadedly connected to the second bidirectional lead screw 233, and the two clamping assemblies 22 are symmetrically arranged, and a driving motor 234 is also fixedly connected to the limiting portion 231, and the output shaft of the driving motor 234 is connected to the end of the second bidirectional lead screw 233. During specific operation, the second bidirectional lead screw 233 is driven to rotate by the driving motor 234. Since the clamping assembly 22 is threadedly connected to the second bidirectional lead screw 233 and can only slide in the sliding groove 232, the rotation of the second bidirectional lead screw 233 drives the two clamping assemblies 22 to slide relative to each other.

[0037] In another embodiment provided by the present invention, a working cavity 11 is provided in the strip-shaped sliding body 1, and an extension direction of the working cavity 11 is parallel to an extension direction of the length of the strip-shaped sliding body 1. Two sliders 12 are slidably installed in the working cavity 11, and one end of the slider 12 extends outside the working cavity 11. The two grabbing claws 2 are respectively installed at one end of the two sliders 12 located outside the working cavity 11, so that the sliders 12 can only slide along the extension direction of the length of the strip-shaped sliding body 1.

[0038] In another embodiment provided by the present invention, the driving unit 21 includes a first bidirectional lead screw 211 rotatably installed in the working chamber 11, the slider 12 is threadedly connected to the first bidirectional lead screw 211, the two sliders 12 are symmetrically arranged, and a servo motor 212 is also installed on the outer wall of the strip sliding body 1, and the output shaft of the servo motor 212 is fixedly connected to the end of the first bidirectional lead screw 211; when it is necessary to increase the clamping distance, the first bidirectional lead screw 211 is driven to rotate in the forward direction by the servo motor 212. Since the slider 12 is threadedly connected to the first bidirectional lead screw 211 and the slider 12 can only slide in the working chamber 11, the two sliders 12 slide in a direction away from each other and drive the two grabbing claws 2 away from each other; by the same token, when it is necessary to reduce the clamping distance, the first bidirectional lead screw 211 is driven to rotate in the opposite direction by the servo motor 212, thereby driving the two grabbing claws 2 closer to each other.

[0039] In another embodiment provided by the present invention, the clamping assembly 22 includes a clamping portion 221 threadedly connected to a second bidirectional lead screw 233, the lower end of the clamping portion 221 is rotatably connected to a pressing portion 223 (the pressing portion 223 is fixedly connected to the rotating shaft 222) through a rotating shaft 222, the pressing portion 223 is a rod-shaped structure, and a torsion spring (not shown in the figure) is also sleeved on the rotating shaft 222, and the torsion spring is used to maintain the initial state between the pressing portion 223 and the clamping portion 221; the clamping portion 221 is a square plate-shaped structure, and the extending direction of the clamping portion 221 is perpendicular to the axis of the second bidirectional lead screw 233, so that when the limiting portion 231 is placed horizontally, the clamping portion 221 can move in the horizontal direction and clamp the workpiece; the end of the pressing portion 223 away from the clamping portion 221 is inclined in a direction close to each other, and the end of the pressing portion 223 close to each other is a hook-shaped structure, and the hook structure facilitates the pressing portion 223 to move with the workpiece The clamping portion 221 can move the top pressing portion 223 synchronously with the top pressing portion 223, and the top pressing portion 223 can move synchronously with the top pressing portion 223. The top pressing portion 223 can contact and wrap the workpiece. In addition, the inclined top pressing portion 223 can gradually push the workpiece upward during relative movement. Specifically, when the grabbing claw 2 moves as a whole to the outside of the workpiece and stops moving, the driving motor 234 is started. At this time, the second bidirectional lead screw 233 rotates and drives the two clamping portions 221 to approach each other, and the clamping portion 221 drives the top pressing portion 223 to move synchronously. Since the top pressing portion 223 is inclined in the direction of approaching each other, the bottom of the top pressing portion 223 first contacts the outer wall of the workpiece, and the clamping portion 221 continues to move so that the top pressing portion 223 approaches each other and pushes the workpiece upward, and then the workpiece moves between the two clamping portions 221 and is clamped. At this time, the top pressing portion 223 restricts the bottom of the workpiece to stabilize the state of the workpiece when it moves. In this way, the above technical solution can be used to clamp workpieces of different diameters, wherein the top pressing portion 223 not only has the function of restricting the bottom of the workpiece, but also can lift the workpiece during movement.

[0040] In another embodiment provided by the present invention, an elastic pre-stress rod 224 is slidably provided on the clamping portion 221, and the ends of the two elastic pre-stress rods 224 that are close to each other extend between the two clamping portions 221, and the shortest distance between the ends of the elastic pre-stress rods 224 that are close to each other is defined as a first distance, and the shortest distance between the ends of the pressing portions 223 that are close to each other is defined as a second distance. In addition, the pressing portion 223 can contact the workpiece first by controlling the relative position of the clamping assembly 22 and the workpiece, and a pre-stress spring 225 is connected between the elastic pre-stress rod 224 and the clamping portion 221, and a connecting rope 226 is wound on the rotating shaft 222, and the movable end of the connecting rope 226 movably passes through the clamping portion 221 and is connected to the elastic pre-stress rod 224; when When the clamping parts 221 approach each other, the pressing part 223 contacts the workpiece first, and the clamping parts 221 continue to move so that the elastic pre-stressing rod 224 contacts the surface of the workpiece and the elastic pre-stressing rod 224 is squeezed. At this time, the pre-stressing spring 225 is stretched, and the surface of the workpiece is clamped by the elastic pre-stressing rod 224. In addition, the elastic pre-stressing rod 224 drives the connecting rope 226 to move during the movement, thereby rotating the rotating shaft 222 and synchronously driving the pressing part 223 to rotate in the direction of approaching each other. In this way, the position of the elastic pre-stressing rod 224 is related to the rotation of the pressing part 223. As long as the workpiece is clamped between the elastic pre-stressing rods 224, the pressing part 223 cannot rotate reversely, which can avoid the situation where the workpiece is too heavy to squeeze the pressing part 223 to rotate reversely and fall out.

[0041] An embodiment of the present invention also provides a method for turning and grasping a workpiece, which is based on a turning and grasping system for a workpiece. When a longer workpiece needs to be grasped, the method includes the following steps: the robotic arm drives the strip sliding body 1 to move above the workpiece, and drives the two grasping claws 2 away from each other through the driving unit 21 to expand the distance between the two grasping claws 2, and then grasps the two ends of the workpiece through the grasping claws 2. After the grasping is completed, the workpiece is controlled to move through the robotic arm to move the workpiece to the next working position or collection position.

[0042] For further information, see Figure 5 and Figure 8 The two pressing parts 223 are not in the same vertical plane, but are arranged alternately. That is to say, when the two pressing parts 223 rotate in a direction approaching each other, the two will not directly contact each other, thereby avoiding movement interference between the two pressing parts 223. Moreover, since the rotation angle of the pressing part 223 is certain (related to the size of the first spacing of the elastic pre-pressing rod 224), excessive rotation will not occur when clamping a workpiece with a smaller diameter.

[0043] Further, see Figure 5-7Obviously, in the prior art, an arc-shaped grasping structure is generally used to grasp the workpiece, which can not only clamp the outer wall of the workpiece through the side wall of the arc-shaped grasping structure, but also push the workpiece upward during the tightening process of the arc-shaped grasping structure, so that the workpiece can contact with the front end of the robot arm after moving up and the top of the workpiece can be pressed against the front end of the robot arm, thereby increasing the contact surface of the workpiece and stably clamping the workpiece. However, for workpieces with smaller diameters, the clamping assembly 22 in the above embodiment is obviously unable to complete the pressing of the top of the workpiece, and the elastic pre-compression rod 224 is in a fixed state in the extension direction of the clamping assembly 22. For workpieces with smaller diameters, the workpiece may be directly clamped between the clamping parts 221 but cannot be clamped between the elastic pre-compression rods 224, and the top pressing part 223 cannot be restricted. For this reason, the present embodiment further improves the clamping assembly 22; it also includes a pressing unit 24, and the pressing unit 24 includes a clamping unit 24 located near the middle of the clamping part 221 The through hole on one side of the limiting portion 231, the middle part of the clamping portion 221 is also provided with a square groove 241, a driving screw 242 is rotatably installed in the square groove 241, the end of the driving screw 242 close to the through hole rotates through the square groove 241 and extends into the through hole, the end of the driving screw 242 located in the square groove 241 is fixed with a driven gear 243, the limiting portion 231 is fixed with a driving rack 244, the driving rack 244 moves through the through hole and Engaged with the driven gear 243, a moving block 245 is slidably installed in the square groove 241, and the moving block 245 is threadedly connected to the driving screw 242; it should also be noted that, in this embodiment, the elastic pre-compression rod 224 is no longer slidably installed on the clamping portion 221, but slides through the moving block 245, and accordingly, the pre-compression spring 225 is connected between the moving block 245 and the elastic pre-compression rod 224, and the movable end of the connecting rope 226 is still connected to the elastic pre-compression rod 224.

[0044] In this embodiment, when the two clamping parts 221 approach each other, the driving rack 244 and the driven gear 243 move relative to each other. Since the driving rack 244 meshes with the driven gear 243, the driven gear 243 is driven by the driving rack 244 and rotates. At this time, the driving screw 242 rotates synchronously and drives the moving block 245 to slide in the square groove 241 in the direction close to the top pressing part 223 (this direction is defined as downward). In other words, the closer the two clamping parts 221 are to each other, the closer the moving block 245 is to each other. The closer the moving block 245 is to the pressing portion 223, the more it can drive the elastic pre-compression rod 224 to synchronously approach the pressing portion 223. That is to say, the movement of the elastic pre-compression rod 224 is a combination of sliding in two directions, one is sliding in a direction parallel to the second bidirectional lead screw 233, and the other is sliding in a direction parallel to the driving lead screw 242. When a workpiece with a smaller diameter contacts the pressing portion 223 first, the pressing portion 223 pushes the workpiece to move in a direction close to the limiting portion 231 (this direction is defined as upward).

[0045] At this time, since the elastic pre-compression rod 224 also moves downward and gradually contacts the workpiece, the contact between the elastic pre-compression rod 224 and the workpiece includes two situations, namely, an extrusion condition and a downward pressing condition. In the extrusion condition, after the workpiece moves between the two elastic pre-compression rods 224, the ends of the elastic pre-compression rods 224 that are close to each other just clamp the side wall of the workpiece; in the downward pressing condition, before the elastic pre-compression rod 224 contacts the workpiece, the size of the first spacing is already smaller than the diameter of the workpiece, that is, at this time, the downward movement of the elastic pre-compression rod 224 will only make the workpiece press tightly under the elastic pre-compression rod 224. The elastic pre-stressing rod 224 is pressed against the top pressure portion 223 to push the top pressure portion 223 upward, thereby further pressing the bottom of the workpiece. In this way, even a workpiece with a smaller diameter can be stably clamped between the elastic pre-stressing rod 224 and the top pressure portion 223.

[0046] See also Figure 5For the downward pressing condition, the shape of the elastic pre-stressing rod 224 can be further designed to overcome the above technical problems. An arc surface 246 is provided on the lower side of one end of the elastic pre-stressing rod 224 that is close to each other. The arc surface 246 is an inner concave surface. During the downward pressing condition, the arc surface 246 first contacts the surface of the workpiece. At this time, the workpiece exerts upward and outward pressure (away from the workpiece) on the arc surface 246, and for the elastic pre-stressing rod 224, inward and downward pressure is also applied to the workpiece; in this way, the elastic pre-stressing rod 224 is squeezed to move outward, so that the top pressing part 223 rotates and restricts the top pressing part 223, and the arc surface 246 also applies downward pressure to the workpiece, so that the upper and lower ends of the workpiece are subjected to a certain pressure, which is convenient for stable clamping.

[0047] For further information, see Figure 8 The size of the pressure on the workpiece is determined by the size of the first spacing in the initial state. The smaller the first spacing, that is, the longer the elastic pre-stressing rod 224 is extended (extending in the direction of approaching each other), the longer the stroke of the elastic pre-stressing rod 224 being squeezed and slid is, and the greater the stretching distance of the pre-stressing spring 225, the greater the pressure on the workpiece surface. For this reason, the present embodiment provides a further solution, in which the ends of the elastic pre-stressing rods 224 that are close to each other are screwed with a threaded rod 247, and the ends of the threaded rods 247 that are close to each other are truncated cone-shaped structures, and the closer the truncated cone-shaped structures are to each other, the smaller their diameters are; when encountering workpieces of different diameters or weights, the threaded rod 247 can be rotated to make the threaded rod 247 retract or extend, thereby controlling the stroke of the elastic pre-stressing rod 224 being squeezed and slid. In this way, the pressure of the elastic pre-stressing rod 224 on the workpiece surface is adjusted to adapt to different working conditions. In addition, even if the threaded rod 247 rotates, the truncated cone-shaped structure can ensure that pressure is generated in multiple directions on the workpiece.

[0048] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A turning and grasping system for a workpiece, comprising a robotic arm, characterized in that: A strip-shaped sliding body is fixed at the front end of the mechanical arm, two grabbing claws are slidably mounted on the strip-shaped sliding body, and a driving unit is also arranged in the strip-shaped sliding body; The driving unit drives the two grasping claws to move relative to each other to adjust the distance between the two grasping claws; The grabbing claw comprises two gripping assemblies and a power unit for driving the two gripping assemblies to move relative to each other; The power unit includes a limiting portion fixed to an end of the slider away from the mechanical arm, a sliding groove is provided at one end of the limiting portion away from the strip sliding body, a second bidirectional lead screw is rotatably installed in the sliding groove, one end of the clamping assembly located in the sliding groove is threadedly connected to the second bidirectional lead screw, the two clamping assemblies are symmetrically arranged, a driving motor is also fixedly connected to the limiting portion, and the output shaft of the driving motor is connected to the end of the second bidirectional lead screw; The clamping assembly comprises a clamping part threadedly connected to the second bidirectional lead screw, the lower end of the clamping part is rotatably connected to a pressing part via a rotating shaft, and a torsion spring is further connected between the pressing part and the clamping part; The two pressing parts are not in the same vertical plane, but are arranged alternately; It also includes a pressing unit, which includes a through hole opened on one side of the middle part of the clamping part close to the limiting part, and a square groove is also opened in the middle part of the clamping part, a driving screw is rotatably installed in the square groove, one end of the driving screw close to the through hole rotates through the square groove and extends into the through hole, a driven gear is fixedly arranged at one end of the driving screw located in the square groove, a driving rack is fixed on the limiting part, the driving rack movably passes through the through hole and meshes with the driven gear, a moving block is slidably installed in the square groove, and the moving block is threadedly connected to the driving screw; An elastic pre-compression rod is slidably penetrated on the moving block, a pre-compression spring is connected between the moving block and the elastic pre-compression rod, and a movable end of a connecting rope is connected to the elastic pre-compression rod.

2. A workpiece turning gripping system according to claim 1, characterized in that: A working cavity is provided in the strip-shaped sliding body, and two sliding blocks are slidably installed in the working cavity. One end of the sliding block extends outside the working cavity, and the two grabbing claws are respectively installed at one end of the two sliding blocks located outside the working cavity.

3. A workpiece turning gripping system according to claim 2, characterized in that: The driving unit includes a first bidirectional lead screw rotatably installed in the working chamber, the slider is threadedly connected to the first bidirectional lead screw, the two sliders are symmetrically arranged, and a servo motor is also installed on the outer wall of the strip sliding body, and the output shaft of the servo motor is fixedly connected to the end of the first bidirectional lead screw.

4. A workpiece turning gripping system according to claim 1, characterized in that: The clamping portion is a square plate-shaped structure, and the extending direction of the clamping portion is perpendicular to the axis of the second bidirectional lead screw.

5. A workpiece turning gripping system according to claim 4, characterized in that: The pressing portion is inclined toward an end thereof which is away from the clamping portion and approaches each other.

6. A method for turning and grasping a workpiece, characterized in that: The turning and grasping system of the workpiece according to any one of claims 1 to 5 comprises the following steps: The robot arm drives the strip-shaped sliding body to move above the workpiece, drives the two grasping claws to move away from each other through the driving unit to expand the distance between the two grasping claws, and then grasps the two ends of the workpiece through the grasping claws.

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