A kind of tensioned integral quick response gripper based on multi-stable equilibrium configuration design

Abstract

This invention belongs to the field of clamping machinery technology, specifically disclosing a tensioned integral fast-response gripper based on a multi-steady-state equilibrium configuration design. It includes a tensioned integral joint and a clamping mechanism. The tensioned integral joint includes an upper triangular plate and a lower triangular plate rotatably connected around a apex bearing. Springs are respectively installed at the bottom corners of the upper and lower triangular plates. A rope is connected to the lower end of each spring to form an equivalent spring, and the rope is connected to a spring adjustment mechanism installed on the side of the lower triangular plate. The clamping mechanism includes an upper gripper corresponding to the surface of the upper triangular plate and a lower gripper corresponding to the surface of the lower triangular plate. Both the upper and lower grippers are designed as inclined U-shapes, and the U-shaped side of the upper gripper closer to the lower gripper is extended to form a trigger area. This gripper has a simple structure, is lightweight, can store elastic potential energy and release it during operation, and possesses easy triggering and fast response capabilities, enabling it to capture objects approaching the gripper from different directions and at different speeds.

Description

Technical Field

[0001] This invention belongs to the field of clamping machinery technology, specifically relating to a tensioning integral fast-response gripper based on a multi-steady-state equilibrium configuration design. Background Technology

[0002] Currently, most grippers on the market consist of rigid mechanisms, with the gripper's clamping and releasing functions driven by a motor. There are some typical rigid gripper designs, such as the parallel clamping rigid gripper designed by the China University of Civil Engineering and Architecture, etc. Figure 1 As shown, the gripper consists of a linkage mechanism, a gear set, and a motor. The motor and gear set drive the movement of the linkage mechanism. Due to the proper configuration of the lengths between the linkages, it approaches the object parallel to its surroundings during the gripping process. The motor is relatively small and has limited driving capacity. Furthermore, the gear set further reduces the speed, resulting in generally slow response times and a poor ability to capture moving objects. Moreover, because the gripper is entirely composed of a rigid mechanism, it inevitably generates unbuffered rigid impacts during object gripping. The faster the response time or the faster the object is grasped, the greater the stress impact, which to some extent limits the rigid gripper's ability to quickly capture objects. To reduce the stress impact generated during this process, force sensors or displacement sensors need to be added to the gripper, which would further increase the gripper's weight and cost.

[0003] Researchers have also explored the grippers of tensioned monolithic structures. These structures consist of a series of pressure-bearing units and tension-providing units (ropes or springs). They have a relatively small mass, which is beneficial for lightweight design. Furthermore, when subjected to impact, the springs can absorb energy and produce relatively flexible deformation, thus providing ideal cushioning capabilities. For example, the three-finger tensioned monolithic structure gripper designed by Shandong University... Figure 2 As shown, it consists of a conical tensioned integral structural unit. This gripper can grasp objects of different sizes, shapes, and materials, solving the problem of the heavy weight of traditional mechanical grippers and improving the ability to flexibly grasp objects. However, it still lacks in response speed. The process of gripping an object requires a motor to pull the ropes on the tensioned integral structure, slowly driving its deformation to gradually grasp the object. At the same time, driving the entire gripper also requires a large number of motors, so its ability in terms of miniaturization and rapid response is still not ideal. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a tensioned integral fast-response gripper based on a multi-steady-state equilibrium configuration design. It has a simple structure, is lightweight, and can capture objects approaching the gripper from different directions and at different speeds. It is easy to trigger and has a fast response capability, making it suitable for capturing and gripping fast-moving objects in a space environment.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] A tensioning integral fast-response gripper based on a multi-stable equilibrium configuration design includes a tensioning integral joint and a gripping mechanism;

[0007] The tensioning integral joint includes an upper triangular plate and a lower triangular plate that are rotatably connected at their apex, and springs are respectively provided at the two bottom corners of the upper and lower triangular plates.

[0008] The lower end of the spring is connected to a rope to form an equivalent spring, and the rope is connected to a spring adjustment mechanism installed on the side of the lower triangular plate.

[0009] The clamping mechanism includes an upper clamping jaw that is mounted and connected to the surface of the upper triangular plate, and a lower clamping jaw that is mounted and connected to the surface of the lower triangular plate. Both the upper and lower clamping jaws are set as inclined U-shapes, and the U-shaped side of the upper clamping jaw near the lower clamping jaw is extended to form a trigger area.

[0010] Preferably, the upper triangular plate and the lower triangular plate are respectively connected by bolts to an upper connecting plate and a lower connecting plate with similar shapes. The upper connecting plate and the lower connecting plate are hinged together by bearings, and a baffle is provided to restrict the movement of the bearings. The baffle is fastened to the connecting hole in the middle by bolts.

[0011] Preferably, the spring adjustment mechanism includes a slide block connected to the end of the rope, the slide block being threadedly connected to a lead screw disposed in the housing, the lead screw being rotatably connected inside the housing, and one end of the lead screw penetrating the housing; a limiting groove is also provided inside the housing to slide in connection with the slide block, the housing is mounted on the side of the lower triangular plate by a mounting plate provided on the side, and a top cover is provided on the end of the housing relative to the end through which the lead screw penetrates, and is connected to the housing.

[0012] Preferably, the ropes are wound around pulleys located at the bottom corners of the lower triangular plate and then connected to the slide block.

[0013] The beneficial effects of this invention are:

[0014] (1) The main structure of the gripper includes a tensioning integral joint and a clamping mechanism. It has a simple structure and light weight, which helps to achieve lightweight design.

[0015] (2) The introduction of the elastic unit enables the gripper to store elastic potential energy and release it during operation, providing energy that is easily triggered and responds quickly, making it suitable for capturing fast-moving objects in a space environment. In addition, the elastic unit gives the gripper a certain buffering capacity, reducing the impact generated when gripping objects.

[0016] (3) On the basis of the rotating and connected upper and lower triangular plates, upper and lower jaws for gripping objects are added. The lower jaw is fixed to the lower triangular plate and the lower triangular plate is connected to the robotic arm, etc. The upper jaw is designed with a trigger area. When it is impacted, it will drive the tensioning of the entire joint to deform. The upper and lower triangular plates have similar structural shapes. When deforming to the gripping state, they also have the ability to grip objects of different volumes. Due to the large trigger area, the jaw can grip objects that approach the jaw from multiple directions and positions, thus expanding its ability to capture moving objects.

[0017] (4) The mechanical properties of the gripper are easy to adjust. By adjusting the screw to drive the slide block to move, the pulling rope can change the equivalent original length of the spring and thus adjust its mechanical properties. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an existing parallel clamping rigid gripper;

[0020] Figure 2 A schematic diagram of the existing three-finger tensioning overall structure gripper;

[0021] Figure 3 This is a schematic diagram of the overall isometric structure of the present invention;

[0022] Figure 4 This is an exploded view of the tensioned integral joint of the present invention;

[0023] Figure 5 This is a front view schematic diagram of the tension integral joint structure of the present invention;

[0024] Figure 6 This is an exploded view of the spring adjusting mechanism of the present invention;

[0025] Figure 7 This is a schematic diagram of the multistable state of the tension integral joint of the present invention;

[0026] Figure 8 The diagrams illustrate the actual process of a gripper capturing a moving object, where (a) is a diagram of capturing a tennis ball with an initial velocity of 2 m / s, (b) is a diagram of capturing a tennis ball with an initial velocity of 4 m / s, (c) is a diagram of capturing a baseball with an initial velocity of 2 m / s, and (d) is a diagram of capturing a baseball with an initial velocity of 4 m / s.

[0027] Figure 9This is a schematic diagram illustrating the actual process of a gripper capturing objects approaching it from different directions.

[0028] Figure 10 This is a schematic diagram of the structural parameters of the tensioned integral joint in Example 2;

[0029] In the attached diagram, the structural names represented by each number are as follows:

[0030] 1-Upper triangular plate, 101-Upper connecting plate, 2-Lower triangular plate, 201-Lower connecting plate, 3-Spring, 301-Rope, 4-Upper gripper, 401-Trigger area, 5-Lower gripper, 6-Baffle, 7-Bearing, 8-Connecting hole, 9-Bolt, 10-Pulley, 11-Spring adjustment mechanism, 1101-Slide seat, 1102-Lead screw, 1103-Housing, 1104-Limiting groove, 1105-Mounting plate, 1106-Top cover, 1107-Drive motor. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Example 1

[0033] To address the current limitations of integrated tensioning structure grippers in terms of miniaturization and rapid response, please refer to... Figures 3 to 6 As shown, a tensioning integral fast-response gripper based on a multi-steady-state equilibrium configuration design is proposed, including a tensioning integral joint and a clamping mechanism;

[0034] The tensioning integral joint is mainly composed of two triangular rigid bodies, an upper triangular plate 1 and a lower triangular plate 2, which are rotatably connected at their apex. Springs 3 are respectively installed at the base corners of the upper triangular plate 1 and the lower triangular plate 2 to connect them, forming a complete tensioning integral joint. (See reference...) Figure 7 The diagram shows a multi-stable state. In the initial state, the double-triangle structure of the upper triangle 1 and the lower triangle 2 is in a high-energy stable equilibrium state, storing a certain amount of elastic potential energy. After being appropriately triggered, it will spontaneously release the elastic potential energy and deform towards a low-energy stable equilibrium state.

[0035] The upper triangular plate 1 and the lower triangular plate 2 are respectively connected by bolts 9 to the upper connecting plate 101 and the lower connecting plate 201, which are similar in shape. The upper connecting plate 101 and the lower connecting plate 201 are hinged together by bearings 7, and a baffle 6 is provided to restrict the movement of the bearings 7. The baffle 6 is connected and fastened to the connecting hole 8 by bolts 9 in the middle.

[0036] The lower end of spring 3 is connected to rope 301 to form an equivalent spring. By changing the length of rope 301, the equivalent original length can be changed. By adding rope 301, the original length of spring 3 can be extended. In addition, changing the length of rope 301 can also modify the original length of the equivalent spring. Rope 301 is connected to spring adjustment mechanism 11 installed on the side of lower triangular plate 2.

[0037] The spring adjustment mechanism 11 includes a slide block 1101 connected to the end of the rope 301. The slide block 1101 is threadedly connected to a lead screw 1102 disposed in the housing 1103. The lead screw 1102 is rotatably connected inside the housing 1103, and one end of the lead screw 1102 passes through the housing 1103. A limiting groove 1104 is also provided in the housing 1103 to slide in connection with the slide block 1101. The housing 1103 is mounted on the side of the lower triangular plate 2 by a mounting plate 1105 provided on the side. A top cover 1106 is provided on the end of the housing 1103 that is penetrated by the lead screw 1102 and is connected to the housing 1103.

[0038] After adjusting the direction of the rope 301 by winding around the pulley 10 located at the bottom corner of the lower triangular plate 2, the rope 301 is connected to the slide block 1101.

[0039] To quickly adjust the rotation of the lead screw 1102, thereby adjusting the original length of the equivalent spring, a drive motor 1107 is installed at the end of the lead screw 1102 that passes through the housing 1103. The drive motor 1107 is a forward and reverse motor. Rotating the lead screw 1102 causes the slide 1101 to move up or down, which is equivalent to lengthening or shortening the rope 301, thereby changing the equivalent original length of the spring 3. This design allows for adjustment of the original length of the equivalent spring 3 without disassembling the spring 3, making the mechanical properties of the gripper easier to control.

[0040] The clamping mechanism includes an upper jaw 4 that is mounted and connected to the surface of the upper triangular plate 1 by bolts 9, and a lower jaw 5 that is mounted and connected to the surface of the lower triangular plate 2 by bolts 9.

[0041] Both the upper gripper 4 and the lower gripper 5 are set as inclined U-shapes, and the U-shaped side of the upper gripper 4 near the lower gripper 5 is extended to set the trigger area 401.

[0042] The lower gripper 5 and the lower triangular plate 2 of the tensioning joint are connected and fixed to the robotic arm. The upper gripper 4 has a trigger area 401, which is used to receive external impact, causing the tensioning joint to deform, so that the upper gripper 4 and the lower gripper 5 can clamp the object together.

[0043] Working principle: The lower triangular plate 2 is connected to the robotic arm, etc. The upper gripper 4 is designed with a trigger area 401. After being impacted, it will drive the tensioning joint to deform. The upper triangular plate 1 and the lower triangular plate 2 have similar structural shapes. When deforming to the gripping state, it also has the ability to grip objects of different volumes. Because the trigger area 401 is large, the gripper can grip objects that approach the gripper from multiple directions and positions. It has the ability to be easily triggered and respond quickly, and is suitable for capturing fast-moving objects in a spatial environment.

[0044] like Figure 8 and Figure 9 As shown, in actual work, the gripper can successfully capture objects of different speeds and masses, as well as objects approaching the gripper from different directions.

[0045] Example 2

[0046] Fabrication of the tensioning integral fast-response gripper based on multi-stable equilibrium configuration design in Example 1:

[0047] The tensioned integral joint is made of 3D-printed PLA material and laser-cut acrylic sheet material, connected in the middle by a 688ZZ bearing 7 with an inner diameter of 16mm, an outer diameter of 8mm, and a thickness of 5mm to reduce friction during joint movement. Figure 10 As shown, the specific geometric parameters of the triangular structure of the tension integral joint are as follows: a1=90.4063mm, b1=88.1849mm, α=27.1799°, a2=83.7668mm, b2=86.8546mm, β=27.1799°.

[0048] Spring 3 is a spring with a diameter of 4mm, a length of 50mm, and a wire diameter of 0.8mm. The original length of spring 3 is 50mm, but it can be increased or changed by attaching rope 301. The equivalent original length parameters of spring 3 are designed as follows: L 01 =113.0064mm, L 02 = 105.8726mm. It can be calculated that the extended length of rope 301 is: s 01 =63.0064mm, s 02 =55.8726mm.

[0049] Using 3D printing and laser cutting technologies, the required structures can be manufactured with relatively high precision according to the designed STL and DWG format drawings. The connections between these structures are mainly secured with bolts and nuts.

[0050] The spring adjustment mechanism 11 is fabricated using a 3D printed structure. The 3D printed structure can be precisely manufactured according to the designed STL format drawings. The lead screw 1102 is 50mm long, and the slide 1101 moves approximately 50mm on the lead screw 1102; that is, the range of adjustment for the original length of the equivalent spring 3 is approximately 50mm. This mechanism is connected by bolts 9, nuts, and a tensioning integral joint.

[0051] The clamping mechanism is made of laser-cut acrylic sheet material. Using laser cutting technology, the required structure can be manufactured with high precision according to the designed DWG format drawings. These structures are connected and fastened to the tensioning integral joint by bolts and nuts.

[0052] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not describe all details exhaustively, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification.

Claims

1. A kind of tensioned integral quick response gripper based on multi-stable equilibrium configuration design, it is characterized by, Including tensioning integral joints and clamping mechanisms; The tensioning integral joint includes an upper triangular plate (1) and a lower triangular plate (2) that are rotatably connected at the top corners. The two bottom corners of the upper triangular plate (1) and the lower triangular plate (2) are respectively connected by springs (3). The lower end of the spring (3) is connected to a rope (301) to form an equivalent spring. The rope (301) is connected to a spring adjustment mechanism (11) installed on the side of the lower triangular plate (2). The clamping mechanism includes an upper jaw (4) that is mounted and connected to the surface of the upper triangular plate (1), and a lower jaw (5) that is mounted and connected to the surface of the lower triangular plate (2). Both the upper jaw (4) and the lower jaw (5) are set as inclined U-shapes. The lower gripper (5) is fixedly connected to the lower triangular plate (2), and the lower triangular plate (2) is fixedly connected to the robotic arm. The upper gripper (4) has a U-shaped side extending near the lower gripper (5) to provide a trigger area (401). The trigger area (401) is used to receive external force impact to drive the overall joint deformation of tension, thereby realizing the upper gripper (4) and the lower gripper (5) to clamp the object together.

2. The tensioning integral fast-response gripper based on a multi-stable equilibrium configuration design according to claim 1, characterized in that, The upper triangular plate (1) and the lower triangular plate (2) are respectively connected by bolts (9) to an upper connecting plate (101) and a lower connecting plate (201) with similar shapes. The upper connecting plate (101) and the lower connecting plate (201) are hinged together by a bearing (7), and a baffle (6) is provided to restrict the movement of the bearing (7). The baffle (6) is connected and fastened to the connecting hole (8) by bolts (9) in the middle.

3. The fast response tensegrity based gripper designed based on multi-stable equilibrium configurations of claim 1, wherein, The spring adjustment mechanism (11) includes a slide (1101) connected to the end of the rope (301). The slide (1101) is threadedly connected to a lead screw (1102) located inside the housing (1103). The lead screw (1102) is rotatably connected inside the housing (1103), and one end of the lead screw (1102) passes through the housing (1103). A limiting groove (1104) is also provided inside the housing (1103) to slide and connect with the slide (1101). The housing (1103) is installed on the side of the lower triangular plate (2) through a mounting plate (1105) provided on the side. A top cover (1106) is provided on the end of the housing (1103) that is connected to the end through which the lead screw (1102) passes.

4. The fast response tensegrity gripper based on multi-stable equilibrium configurations of claim 3, wherein, The rope (301) is connected to the slide block (1101) after passing around the pulley (10) set at the bottom corner of the lower triangular plate (2).

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