Portable screwing grabbing device with adjustable opening and clamping force

Abstract

The utility model discloses a portable screwing grabbing device with an opening and adjustable clamping force. The portable screwing grabbing device comprises a clamping mechanism, a spiral groove mechanism, a clamping force adjusting mechanism and a driving mechanism. The clamping mechanism comprises a plurality of clamping fingers and a finger seat; the spiral groove mechanism comprises a spiral seat and a ring sleeve; the clamping force adjusting mechanism comprises a rack, an adjusting bolt, a friction block, an elastic frame and a fixing nut. The driving mechanism comprises a motor, a first shaft sleeve and a long shaft sleeve. An output shaft of the motor is connected with a shaft sleeve I which is connected with a long shaft sleeve; a friction ring, a spiral seat and a ring sleeve are sleeved outside the long shaft sleeve, the end part of the long shaft sleeve is connected with a finger seat, the finger seat can rotate relative to the ring sleeve and the spiral seat, the finger seat is rotatably connected with a clamping finger, the tail end of each clamping finger is provided with a ball head, the spiral seat is provided with a plurality of arc-shaped grooves with the same number as the ball heads, and the ball heads are connected with the arc-shaped grooves in a sliding manner. The finger seat is provided with multiple groups of pin holes. According to the technology, opening and clamping force adjustment can be achieved, the structure is simple, the weight is light, and the picking efficiency is high.

Description

Technical Field

[0001] The technology relates to the technical field of picking spherical fruits, and specifically is a lightweight twisting and grasping device with adjustable opening and clamping force. Background Art

[0002] In the fruit picking operation, manual picking is inefficient and labor-intensive. With the development of robotics and computer technology, picking robots are gradually showing great potential in picking operations. The gripping device is in direct contact with the picked fruit, and the quality of its structure and principle directly determines the success rate and efficiency of the picking. The current twisting gripping devices are mostly complex in structure and multi-drive picking. The series of picking actions such as grabbing and twisting the fruit need to be achieved through multiple drive sources. The overall structure is complex and heavy, or the opening size and the force of gripping the fruit cannot be adjusted, the scope of application is narrow, or the adjustment method is cumbersome, the reliability is insufficient, and it is time-consuming and labor-intensive. Therefore, the ultimate goal of the robot gripping device is to pursue the lightest weight, the least time, and no recycling of fruits. Summary of the invention

[0003] The technical problem to be solved by the present technology is to provide a portable twisting and grasping device with adjustable opening and clamping force in view of the deficiencies of the above-mentioned prior art. The portable twisting and grasping device with adjustable opening and clamping force can realize two picking actions of grasping and twisting through a single driving source (motor), and the gripping force can be adjusted, and the maximum opening size can be adjusted. It is suitable for picking fruits of different sizes and different resistance to extrusion pressure. The overall structure is simple, the weight is light, and the picking efficiency is high.

[0004] In order to achieve the above technical objectives, the technical solution adopted by this technology is:

[0005] A lightweight twisting and grasping device with adjustable opening and clamping force, comprising a clamping mechanism, a spiral groove mechanism, a clamping force adjustment mechanism and a driving mechanism;

[0006] The clamping mechanism includes a plurality of clamping fingers, a finger seat and a flexible material; the spiral groove mechanism includes a spiral seat, a ring sleeve and a friction ring; the clamping force adjustment mechanism includes a frame, an adjustment bolt, a friction block, an elastic frame and a fixing nut; the driving mechanism includes a motor, a shaft sleeve and a long shaft sleeve;

[0007] The output shaft of the motor is connected to a sleeve, and a sleeve is connected to a long sleeve; a ring frame is provided at the front end of the frame, and a through hole is opened at the center of the bottom of the ring frame; the shoulder of the long sleeve is slidably connected to the outer bottom surface of the ring frame, and passes through the ring frame, friction ring, spiral seat, and ring sleeve in sequence; the ring frame, friction ring, spiral seat, ring sleeve and long sleeve can rotate relatively; the end of the long sleeve is connected to the finger seat, and the long sleeve is used to drive the finger seat to rotate; the finger seat and the ring sleeve and spiral seat can rotate relatively; a plurality of finger grooves evenly distributed in a circle are provided on the finger seat, and a plurality of groups of pin holes are radially provided in the finger grooves, and a clamping finger is rotatably connected in each finger groove, and each clamping finger A ball head is provided at the end, and the spiral seat is provided with a plurality of arc grooves having the same number as the ball heads, and the ball head is slidably connected to the arc groove; the spiral seat is connected to the friction ring, and the friction block is located between the elastic frame and the friction ring, the housing of the motor is connected to the frame, the inner side wall and the bottom surface of the ring frame are slidably connected to the outer side surface of the ring sleeve and the bottom surface of the spiral seat respectively, a groove is provided at the bottom of the ring frame, the elastic frame, the friction block and the friction ring are located in the groove, and a through adjusting bolt hole is provided on the inner wall of the groove, and the bolt rod of the adjusting bolt passes through the square countersunk hole and the adjusting bolt hole on the outer bottom surface of the ring frame in turn, penetrates into the groove and abuts against one end of the elastic frame, and the adjusting bolt is threadedly connected with a fixing nut located in the square countersunk hole.

[0008] Furthermore, the front end of the long shaft sleeve passes through the central through hole at the bottom of the ring frame and is inserted into the inner hole of the finger seat, and the front end of the long shaft sleeve is circumferentially connected to the finger seat and can drive the finger seat to rotate.

[0009] Furthermore, the inner hole of the long shaft sleeve includes a shaft sleeve mounting hole, a countersunk hole and a bolt hole which are connected in sequence, the output shaft of the motor is connected to shaft sleeve one, and shaft sleeve one is connected to a shaft sleeve mounting hole of the long shaft sleeve; the bolt head of the long bolt is located in the countersunk hole, and the bolt rod of the long bolt passes through the bolt hole of the long shaft sleeve and the inner hole of the finger seat in sequence and is connected to the nut, and the nut is located in the central countersunk hole of the finger seat to prevent the finger seat, the ring sleeve, the spiral seat, the friction ring and the long shaft sleeve from spreading axially, and to allow the finger seat and the long shaft sleeve to rotate relative to the spiral seat.

[0010] Furthermore, the clamping fingers have three fingers, and the finger seat is provided with three finger grooves evenly distributed in a circumference, and each finger groove has multiple groups of pin holes, and the clamping fingers are rotatably connected to one group of pin holes through pins. The pitch circle where the center of each group of pin holes is located is different in size, and the maximum opening of the twisting grasping device is adjusted by selecting to rotatably connect the clamping fingers to different groups of pin holes to adapt to different sizes of fruits to be picked, and the overall length of the arc groove must meet the smooth sliding of the clamping fingers when connected to different groups of pin holes.

[0011] Furthermore, a waist-shaped hole for passing the inner hole of the long shaft sleeve and the circumferentially connected friction ring is provided at the center of the spiral seat. The waist-shaped hole is a countersunk hole. There are three arc grooves on the spiral seat. One end of each arc groove is close to the inner hole of the spiral seat, and the other end is close to the outer circumferential surface of the spiral seat. When the screwing torque applied to the arc groove by the ball head of the clamping finger is greater than the preset resistance torque given to the spiral seat by the friction ring, the spiral seat and the finger seat rotate together relative to the frame. Otherwise, the spiral seat and the friction ring are stationary relative to the frame.

[0012] Furthermore, the housing of the motor is fixedly connected to the frame by bolts passing through the motor mounting holes, and a mounting hole that can be connected to the robot wrist is opened on the rear end surface of the frame.

[0013] Furthermore, the friction block is an arc-shaped friction block, and the fixing nut is a square nut. The adjusting bolt and the fixing nut rotate relative to each other while moving axially in the adjusting bolt hole, pushing the elastic frame to drive the friction block to swing back and forth, and cooperating with the elastic restoring force of the elastic frame itself to increase or reduce the resistance torque applied to the friction ring, so as to adjust the clamping force applied by the screwing and grasping device on the fruit.

[0014] Furthermore, there are two friction blocks, two adjusting bolts and two fixing nuts, and the friction blocks are fixed on the inner side surfaces of the two arms of the elastic frame.

[0015] Furthermore, the clamping surfaces of the clamping fingers and the upper surface of the finger seat are covered with flexible materials.

[0016] Furthermore, the clamping force of the clamping fingers can be adjusted by changing the length of the clamping finger portion between the pin and the ball head.

[0017] The beneficial effects of this technology are:

[0018] The motor of this technology drives the finger seat to rotate relative to the spiral seat through the first and long sleeves in turn, and then drives the clamping fingers to open and close. When the three claws are closed and the target fruit is grasped, the motor continues to run. Since the clamping fingers cannot be closed after grasping the target fruit, the ball head of the clamping fingers cannot continue to slide along the inner side of the arc groove of the spiral seat. When the stall torque of the motor is greater than the resistance torque of the friction ring, the clamping fingers and the spiral seat will rotate relative to the frame with the rotation of the motor to achieve the action of twisting the fruit, thereby twisting the fruit off the fruit branch and picking the fruit. The gripping force applied by the clamping fingers on the target fruit can be adjusted by adjusting the resistance torque applied by the friction block on the friction ring through the adjusting bolt. On the other hand, the maximum opening of the clamping fingers can be adjusted by rotating the clamping fingers to different groups of pin holes in the finger groove, thereby realizing the adjustable opening and clamping of two important parameters. The twisting and grasping device provided by this technology can also achieve continuous picking by twisting through a single drive (i.e., a single motor). The overall structure is compact, light in weight, and high in picking efficiency. In short, this technology realizes a twisting grasping device driven by a single motor with adjustable opening and gripping force, which can perform the two actions of grasping and twisting in one go. Compared with the existing technology, the adjustment of gripping force is simpler and more reliable, and compared with other picking claws, it achieves weight reduction and efficiency improvement. One grasping and picking action saves more than one-third of the time. At the same time, the lighter weight due to saving a motor allows the robotic arm to move at a faster speed, saving time and effort, being simple and reliable, and being applicable to a wide range of fruit sizes and fruit pressure resistance. This technology truly makes it possible for a single robot to engage in fruit picking operations with efficiency exceeding that of humans. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of Example 1.

[0020] Figure 2 This is a half-section schematic diagram of Example 1.

[0021] Figure 3 In this embodiment 1, the frame is hidden and the schematic diagram of the clamping force adjustment mechanism is highlighted.

[0022] Figure 4 This is a schematic diagram of the friction torque adjustment principle of this embodiment 1.

[0023] Figure 5 This is a schematic diagram of the rack of Example 1.

[0024] Figure 6 This is a schematic diagram of the finger seat of the first embodiment.

[0025] Figure 7 It is a schematic diagram of the relative position relationship between the clamping fingers and the screw seat.

[0026] Figure 8 It is a three-dimensional diagram of the rack.

[0027] Fig. 9 It is a three-dimensional diagram of the relative position relationship of the frame, friction ring, friction block, elastic frame, etc.

[0028] Fig.10 It is a three-dimensional diagram of the relative position relationship of the friction ring, friction block, elastic frame, adjusting bolt, etc.

[0029] Fig.11 It is a three-dimensional diagram of the relative position relationship of the ring sleeve, friction ring, elastic frame, spiral seat, etc.

[0030] Fig.12 It is another stereoscopic diagram of the relative position relationship of the ring sleeve, friction ring, elastic frame, spiral seat, long bolt, etc.

[0031] Fig.13 It is a schematic diagram of the relative position relationship of two clamping fingers, a finger seat, a friction ring, a long shaft sleeve, a long bolt, etc.

[0032] Fig.14 It is a schematic diagram of the relative position relationship between two clamping fingers, a finger seat, etc.

[0033] Fig.15 This is a schematic diagram of the structure of Example 2 Figure 1 .

[0034] Fig.16 This is a schematic diagram of the structure of Example 2 Figure 2 .

[0035] Fig.17 This is a side view of the structure of embodiment 2.

[0036] Fig.18 This is the front view of the structure of Example 2.

[0037] Fig.19 for Fig.18 Middle BB cross-section.

[0038] Fig. 20 This is a schematic diagram of the structure of the hidden motor, frame and spiral shell of this embodiment 2.

[0039] Fig.21 Schematic diagram of the spiral shell structure Figure 1 .

[0040] Fig. 22 Schematic diagram of the spiral shell structure Figure 2 . DETAILED DESCRIPTION

[0041] The specific implementation of the present technology is further described below according to the accompanying drawings:

[0042] Embodiment 1:

[0043] like Figure 1-Figure 14 As shown, a lightweight screwing and grasping device with adjustable opening and clamping force is characterized in that it includes a clamping mechanism, a spiral groove mechanism, a clamping force adjustment mechanism and a driving mechanism;

[0044] The clamping mechanism includes a plurality of clamping fingers 1, a finger seat 2 and a flexible material 17; the spiral groove mechanism includes a spiral seat 3, a ring sleeve 15 and a friction ring 16; the clamping force adjustment mechanism includes a frame 6, an adjustment bolt 8, a friction block 11, an elastic frame 10 and a fixing nut 9; the driving mechanism includes a motor 7, a shaft sleeve 5 and a long shaft sleeve 4;

[0045] The output shaft 7-1 of the motor 7 is connected to the shaft sleeve 5, and the shaft sleeve 5 is connected to the long shaft sleeve 4; the front end of the frame 6 is provided with a ring frame 6-1, and a through hole is opened at the center of the bottom of the ring frame 6-1; the shoulder of the long shaft sleeve 4 is slidably connected to the outer bottom surface of the ring frame 6-1, and passes through the ring frame 6-1, the friction ring 16, the spiral seat 3, and the ring sleeve 15 in sequence; the ring frame 6-1, the friction ring 16, the spiral seat 3, the ring sleeve 15 and the long shaft sleeve 4 can rotate relative to each other, and the end of the long shaft sleeve 4 is connected to the finger seat 2, and the long shaft sleeve 4 is used to drive the finger seat 2 to rotate, and the finger seat 2 and the ring sleeve 15 and the spiral seat 3 can rotate relative to each other, and the ring sleeve 15 is fixedly connected to the spiral seat 3. The finger seat 2 is provided with three finger grooves 2-1 evenly distributed in a circumference and extending radially, and three groups of pin holes 2-2 are provided radially in the finger grooves 2-1, and a clamping finger 1 is rotatably connected to each finger groove 2-1 through a pin 14, and a ball head 1-1 is provided at the end of each clamping finger 1, and the ball head 1-1 extends into the arc groove 3-1 on the spiral seat 3. The head end of each clamping finger 1 extends out of the finger seat 2.

[0046] The spiral seat 3 is provided with three arc grooves 3-1, and the ball head 1-1 is slidably connected with the arc grooves 3-1; the spiral seat 3 is connected with the friction ring 16, and the friction block 11 is located between the elastic frame 10 and the friction ring 16. The housing of the motor 7 is connected to the frame 6, and the inner side wall and the bottom surface of the ring frame 6-1 are respectively slidably connected with the outer side surface of the ring sleeve 15 and the bottom surface of the spiral seat 3, and the bottom of the ring frame 6-1 is provided with a groove 6-2, and the elastic frame 10, the friction block 11 and the friction ring 16 are located in the groove 6-2. The inner wall of the groove 6-2 is provided with a radially penetrating adjustment bolt hole 6-3, and the bolt rod of the adjustment bolt 8 passes through the square countersunk hole 6-4 and the adjustment bolt hole 6-3 on the outer bottom surface of the ring frame 6-1 in sequence, penetrates into the groove 6-2 and abuts against one end of the elastic frame 10, and the adjustment bolt 8 is threadedly connected with a fixing nut 9 located in the square countersunk hole 6-4.

[0047] The front end of the long shaft sleeve 4 passes through the central through hole at the bottom of the ring frame 6 - 1 and is inserted into the inner hole of the finger seat 2 , and the front end of the long shaft sleeve 4 is circumferentially connected to the finger seat 2 .

[0048] The inner hole of the long shaft sleeve 4 includes a shaft sleeve mounting hole, a countersunk hole and a bolt hole which are connected in sequence. The output shaft 7-1 of the motor 7 is connected to the shaft sleeve 5, and the shaft sleeve 5 is connected to the shaft sleeve mounting hole of the long shaft sleeve 4; the bolt head of the long bolt 12 is located in the countersunk hole, and the bolt rod of the long bolt 12 passes through the bolt hole of the long shaft sleeve 4 and the inner hole of the finger seat 2 in sequence and is connected to the nut 13, and the nut 13 is located in the central countersunk hole 2-3 of the finger seat 2.

[0049] There are three clamping fingers 1, and three finger grooves 2-1 evenly distributed in a circle are arranged on the finger seat 2. Three groups of pin holes 2-2 are arranged in each finger groove 2-1. The clamping fingers 1 are rotatably connected to one group of pin holes 2-2 through a pin 14.

[0050] The center of the spiral seat 3 is provided with an inner hole 3-2 for passing the long shaft sleeve 4 and a waist-shaped hole 3-3 circumferentially connected to the friction ring 16. The waist-shaped hole 3-3 is a countersunk hole. There are three arc grooves 3-1 on the spiral seat 3. One end of each arc groove 3-1 is close to the inner hole of the spiral seat 3, and the other end is close to the outer circumferential surface of the spiral seat 3.

[0051] The housing of the motor 7 is fixedly connected to the frame 6 by bolts passing through the motor mounting holes 6 - 6 .

[0052] The friction block 11 is an arc-shaped friction block, the fixing nut 9 is a square nut, and the adjusting bolt 8 and the fixing nut 9 rotate relative to each other while moving axially in the adjusting bolt hole 6 - 3 .

[0053] There are two friction blocks 11, two adjusting bolts 8 and two fixing nuts 9.

[0054] The clamping surface of the clamping finger 1 and the surface of the finger seat 2 that contacts the fruit are covered with a flexible material 17 to avoid scratching the thin and easily damaged surface of the fruit, while increasing the friction between the finger and the fruit to achieve reliable grip of the fruit.

[0055] The frame 6 of the portable opening and adjustable gripping force twisting grasping device of this embodiment 1 can be installed with a bracket of required length through the frame seat 6-5, and then installed on the wrist joint of the picking robot. The controller and power supply of the twisting grasping device can be integrated with the picking robot for control, or can be independently controlled. The driver matched with the motor is used to drive the motor 7 to work, and a 24V or 12V DC power supply is used to power the motor 7. After the picking robot moves to the picking destination, the mechanical arm of the picking robot drives the portable opening and adjustable gripping force twisting grasping device to move. The initial state of the twisting grasping device is an open state (that is, the ball head 1-1 of the gripping finger is located in the arc groove 3-1 near the axis of the spiral seat 3). When it moves to the position of the target fruit, the target fruit can be just enveloped by the inner side of the gripping finger 1. The twisting and grasping device begins to close, and the controller drives the motor 7 to work. The motor 7 drives the finger seat 2 to rotate through the shaft sleeve 1 5 and the long shaft sleeve 4 in turn, and the finger seat 2 drives the three clamping fingers 1 to rotate. Since the ball heads 1-1 of the three clamping fingers 1 are located in the three arc grooves 3-1 of the spiral seat 3, the ball heads 1-1 slide along the arc grooves 3-1 away from the axis of the spiral seat (or slide toward the position close to the outer circumferential surface of the spiral seat 3), and the middle part of the clamping finger 1 swings around the pin 14 in the finger groove 2-1 of the finger seat 2, and the head ends of the three clamping fingers 1 gradually achieve a closed state, and the target is grasped. Mark the fruit. Before this, because the friction ring 16 cannot rotate relative to the frame 6 under the action of the friction torque applied by the friction block 11, the spiral seat 3 connected to the friction ring 16 through the waist-shaped hole countersunk hole at the bottom center of the spiral seat 3 cannot rotate. In a moment thereafter, because the clamping finger 1 cannot continue to close and the spiral seat 3 cannot rotate, the motor 7 is in a stalled state. After that, the torque output by the motor will increase. When it is greater than the resistance torque applied by the friction block 11 on the friction ring 16, the finger seat 2 continues to rotate together with the grasped fruit, realizing the action of twisting off the fruit handle and picking the fruit. After that, the controller controls the motor 7 to reverse, so that the clamping finger 1 is reset, the picked fruit is released, and a picking cycle is completed. The first-level rotation of this embodiment 1 refers to the rotation of the clamping finger 1 and the finger seat 2 relative to the spiral seat 3 to grasp the fruit, and the second-level rotation refers to the clamping finger 1, the finger seat 2, the ring sleeve 15, and the spiral seat 3 start to rotate relative to the frame 6 and then twist off the fruit. In addition, in order to more accurately control the gripping force applied by the gripping fingers 1 on the fruit surface, a tactile sensor can be provided on the gripping surface of the gripping fingers. When the length of the gripping finger 1 portion between the pin 14 and the ball head 1-1 is changed, the length of the power arm of the gripping finger 1 gripping the fruit can be changed, thereby adjusting the gripping force applied by the gripping fingers 1 on the fruit.

[0056] In the first embodiment of the present invention, the friction block 11 is fixed on the inner side surface of the elastic frame 10, and the inner side surface of the friction block 11 contacts the outer surface of the friction ring 16. When the friction force between the friction block 11 and the friction ring 16 needs to be adjusted, the bolt head of the adjusting bolt 8 is rotated by a tool, and the adjusting bolt 8 rotates relative to the fixing nut 9 and the frame 6. The fixing nut 9 is square, which just matches the square countersunk hole 6-4 on the bottom surface of the ring frame 6-1, and it cannot rotate with the adjusting bolt 8. Therefore, the adjusting bolt 8 will move in the adjusting bolt hole 6-3 while rotating, and its end will push one of the arms of the elastic frame 10 toward the friction ring 16. The elastic frame 10 presses the friction block 11, and the friction force between the friction block 11 and the friction ring 16 increases. The adjustment method of the adjusting bolt 8 on the other side is the same. After the friction between the friction block 11 and the friction ring 16 increases, when the clamping finger 1 grasps the target fruit, the motor 7 needs to further increase the torque to ensure that the motor 7 continues to operate, so that the clamping finger 1, the finger seat 2, the ring sleeve 15, and the spiral seat 3 can realize a common circumferential rotation relative to the frame 6, and the clamping force of the clamping finger 1 on the target fruit increases. Therefore, the present embodiment 1 can adjust the magnitude of the friction between the friction block 11 and the friction ring 16 to adjust the gripping force of the clamping finger 1, and prevent the clamping finger 1 from idling synchronously with the spiral seat 3 and the ring sleeve 15 before the fruit is grasped.

[0057] Embodiment 2:

[0058] like Figure 15-16 As shown, a single-drive two-stage rotating grasping and twisting picking claw comprises a clamping mechanism, a primary twisting mechanism, a secondary twisting mechanism and a driving mechanism.

[0059] like Figure 15-16 As shown, the clamping mechanism includes a plurality of clamping claws 1 and a finger seat 2; the primary screwing mechanism includes a spiral shell 3; the secondary screwing mechanism includes a frame 6, an adjusting bolt 8, a friction block 11, an adjusting spring 10 and an adjusting nut 9; the driving mechanism includes a motor 7, a sleeve 1 5 and a sleeve 2 4.

[0060] like Figure 15-Figure 22As shown, the output shaft 7-1 of the motor 7 is connected to the sleeve 1 5, and the sleeve 1 5 is connected to the sleeve 2 4; the sleeve 2 4 is covered with a spiral shell 3, and the spiral shell 3 and the sleeve 2 4 can rotate relative to each other. The end of the sleeve 2 4 is connected to the finger seat 2, and the sleeve 2 4 is used to drive the finger seat 2 to rotate. The finger seat 2 and the spiral shell 3 can rotate relative to each other. The front end of the spiral shell 3 is provided with a circle of sleeves 3-3, and the rear end of the finger seat 2 is located inside the sleeve 3-3. The finger seat 2 is provided with a plurality of claw grooves 2-1 that are evenly distributed in a circle and extend along the radial direction. The middle part of the clamping claw 1 is rotatably connected to each claw groove 2-1 through a pin, and the end of each clamping claw 1 is provided with a ball head 1-1. The surface of the spiral shell 3 facing the end of the clamping claw 1 is provided with a plurality of arc grooves 3-1 with the same number as the ball head 1-1, and the ball head 1-1 is slidably connected to the arc groove 3-1. The head end of each clamping claw 1 extends out of the finger seat 2.

[0061] A circle of annular friction grooves 3-2 are provided on the outer wall of the spiral shell 3, and a friction block 11 is placed inside the friction groove 3-2. The shell of the motor 7 is connected to the frame 6. The front end of the frame 6 is provided with a circle of ring frame 6-1, and the ring frame 6-1 is located on the outside of the friction groove 3-2 on the outer wall of the spiral shell 3. A plurality of mounting grooves 6-2 are opened on the ring frame 6-1, and a bolt hole is opened inside each mounting groove 6-2. The bolt head of the adjusting bolt 8 is located in the mounting groove 6-2, and the bolt rod of the adjusting bolt 8 passes through the bolt hole of the mounting groove 6-2, the friction groove 3-2 and the reserved hole of the friction block 11 in sequence. The adjusting bolt 8 is threadedly connected with an adjusting nut 9, and the outer side of the bolt rod of the adjusting bolt 8 is covered with an adjusting spring 10. The adjusting nut 9 and the adjusting spring 10 are both located inside the friction groove 3-2, and the adjusting spring 10 is located between the adjusting nut 9 and the friction block 11.

[0062] The ring frame 6 - 1 is connected with a blocking piece 14 for blocking the adjusting bolt 8 in the mounting groove 6 - 2 from moving outwards, and the blocking piece 14 is provided with a through hole 14 - 1 communicating with the mounting groove 6 - 2 .

[0063] The front end of the second sleeve 4 is inserted into the inner hole of the finger seat 2 and the front end of the second sleeve 4 is circumferentially connected to the finger seat 2 .

[0064] The inner hole of the shaft sleeve 2 4 includes a shaft sleeve 1 mounting hole, a countersunk hole and a bolt hole which are connected in sequence. The output shaft 7-1 of the motor 7 is connected to the shaft sleeve 1 5, and the shaft sleeve 1 5 is connected to the shaft sleeve 1 mounting hole of the shaft sleeve 2 4. The bolt head of a bolt 12 is located in the countersunk hole, and the bolt rod of the bolt 12 passes through the bolt hole of the shaft sleeve 2 4 and the inner hole of the finger seat 2 in sequence and is connected to the nut 13. The bolt 12 can prevent the finger seat 2 and the shaft sleeve 1 5 from axial movement. The nut 13 is not in close contact with the finger seat 2, and does not affect the relative rotation of the finger seat 2 and the spiral shell 3.

[0065] There are three clamping claws 1, and the finger seat 2 is provided with three claw grooves 2-1 evenly distributed in a circle and extending along the radial direction. The middle part of the clamping claw 1 is rotatably connected to each claw groove 2-1 through a pin.

[0066] The middle part of the spiral shell 3 is provided with an inner hole for installing the shaft sleeve 2 4 . There are three arc grooves 3 - 1 on the spiral shell 3 . One end of each arc groove 3 - 1 is close to the inner hole of the spiral shell 3 , and the other end is close to the outer circumferential surface of the spiral shell 3 .

[0067] The housing of the motor 7 is fixedly connected to the frame 6 by screws, and the baffle 14 is fixedly connected to the ring frame 6 - 1 by screws.

[0068] The friction block 11 is an arc-shaped friction block, and the adjusting nut 9 is an arc-shaped nut. The adjusting nut 9 can slide radially along the spiral shell 3 in the friction groove 3 - 2 of the spiral shell 3 .

[0069] There are two friction blocks 11, two adjusting bolts 8, two adjusting springs 10 and two adjusting nuts 9.

[0070] The clamping surface of the clamping claw 1 is made of a flexible material, which has a protective effect on the fruit.

[0071] The frame 6 of the single-drive two-stage rotary grasping and twisting picking claw of this embodiment 2 can be installed on a picking robot, and a controller and a power supply are installed on the picking robot (the controller and the power supply can also be installed on the single-drive two-stage rotary grasping and twisting picking claw). The controller is used to drive the motor 7 to work, and the power supply supplies power to the motor 7. Tactile sensors are provided on the concave arc clamping surfaces of the clamping claw 1. After the picking robot runs to the picking destination, the picking robot drives the single-drive two-stage rotary grasping and twisting picking claw to move, so that the target fruit is located on the inner side of the clamping claw 1, and the controller drives the motor 7 to work. The motor 7 drives the finger seat 2 to rotate through the shaft sleeve 1 5 and the shaft sleeve 2 4 in turn, and the finger seat 2 drives the three clamping claws 1 to rotate (the initial state of the clamping claw 1 is the open state, that is, the ball head 1-1 at the end is located in the arc groove 3-1 close to the axis of the spiral shell 3). Since the ball heads 1-1 of the three clamping claws 1 are located in the three arc grooves 3-1 of the spiral shell 3, the ball heads 1-1 slide along the arc groove 3-1, and the ball heads 1-1 at the end gradually slide in the arc groove 3-1 away from the axis of the spiral shell 3 (or close to the outer circumference of the spiral shell 3), and the middle part of the clamping claw 1 swings around the pin in the claw groove 2-1 of the finger seat 2, and the head ends of the three clamping claws 1 The closed state is gradually achieved. After the target fruit is grasped, the tactile sensor sends a signal to the controller, and the controller controls the motor 7 to continue to operate and increase the operating torque of the motor 7. Since the clamping claw 1 cannot be closed after grasping the target fruit, the ball head 1-1 of the clamping claw 1 cannot continue to slide along the arc groove 3-1 of the spiral shell 3. At this time, since the driving force on the spiral shell 3 is greater than the resistance between the spiral shell 3 and the friction block 11, the clamping claw 1 will drive the spiral shell 3 to rotate circumferentially (at this time, the adjusting bolt 8, the adjusting spring 10 and the friction block 11 do not rotate, and the adjusting bolt 8, the adjusting spring 10 and the friction block 11 rotate relative to the annular friction groove 3-2), the clamping claw 1 and the spiral shell 3 will rotate with the rotation of the motor 7, and the clamping claw 1 will rotate circumferentially after clamping the target fruit, realizing the fruit twisting action, thereby twisting the fruit off the fruit branch and realizing the fruit picking. After that, the controller controls the motor 7 to reset, so that the clamping claw 1 is reset, and a picking round is completed. The first-level rotation of the present embodiment 2 refers to the rotation of the gripping claw 1 and the finger seat 2 to grasp the fruit, and the second-level rotation refers to the spiral shell 3 starting to rotate and then twisting off the fruit.

[0072] In the second embodiment, the friction block 11 contacts the inner wall of the annular friction groove 3-2 of the spiral shell 3. When the friction between the friction block 11 and the spiral shell 3 needs to be adjusted, the bolt head of the adjusting bolt 8 is rotated by passing the through hole 14-1 of the stopper through a tool, and the adjusting bolt 8 rotates. The adjusting nut 9 on the adjusting bolt 8 is in the shape of a long arc and is located in the friction groove 3-2. Therefore, the adjusting nut 9 cannot rotate with the adjusting bolt 8. The adjusting nut 9 moves along the thread on the bolt rod of the adjusting bolt 8 in the direction where the adjusting spring 10 is located. The adjusting nut 9 presses the adjusting spring 10, and the adjusting spring 10 presses the friction block 11. The friction between the friction block 11 and the spiral shell 3 increases. After the friction between the friction block 11 and the spiral shell 3 increases, when the clamping claw 1 grasps the target fruit, the controller needs to control the motor 7, and the motor 7 increases the operating torque to ensure that when the motor 7 continues to operate, the spiral shell 3 and the clamping claw 1 can achieve common circumferential rotation. At this time, the clamping degree of the clamping claw 1 on the target fruit increases. Therefore, in the second embodiment, the friction between the friction block 11 and the spiral shell 3 can be adjusted to adjust the gripping tightness of the clamping claw 1, thereby preventing the clamping claw 1 from idling synchronously with the spiral shell 3 before it grips the fruit.

[0073] In Example 2, the motor drives the finger seat to rotate relative to the spiral shell through sleeve 1 and sleeve 2 in turn, and then drives the clamping claws to open and close. When the three claws are closed and the target fruit is grasped, the motor continues to run. Since the clamping claws can no longer be closed after grasping the target fruit, the ball head of the clamping claws can no longer slide along the arc groove of the spiral shell. At this time, the clamping claws and the spiral shell will rotate with the rotation of the motor to achieve the action of twisting the fruit, thereby twisting the fruit off the fruit branch and picking the fruit. Therefore, the picking claws provided by this technology can realize continuous picking by grasping and twisting through a single drive (i.e., a motor), and the overall structure is compact, light in weight, and high in picking efficiency. This technology can also adjust the size of the friction between the friction block and the spiral shell and then adjust the clamping claws to achieve the tightness of grasping. This technology can replace manual picking, which saves time and effort and has a high level of automation; and it can accurately and quickly complete the picking of fruits, and can reduce damage to fruits during the picking process.

[0074] The protection scope of the present technology includes but is not limited to the above embodiments. The protection scope of the present technology shall be based on the claims. Any replacement, deformation, and improvement of the present technology that can be easily thought of by technicians in this field shall fall within the protection scope of the present technology.

Claims

1. A lightweight twisting and gripping device with adjustable opening and clamping force, characterized in that: It includes a clamping mechanism, a spiral groove mechanism, a clamping force adjustment mechanism and a driving mechanism; The clamping mechanism comprises a plurality of clamping fingers (1) and a finger seat (2); the spiral groove mechanism comprises a spiral seat (3), a ring sleeve (15) and a friction ring (16); the clamping force adjustment mechanism comprises a frame (6), an adjustment bolt (8), a friction block (11), an elastic frame (10) and a fixing nut (9); the driving mechanism comprises a motor (7), a shaft sleeve (5) and a long shaft sleeve (4); The output shaft (7-1) of the motor (7) is connected to the shaft sleeve (5), and the shaft sleeve (5) is connected to the long shaft sleeve (4); the front end of the frame (6) is provided with a ring frame (6-1), the center position of the bottom of the ring frame (6-1) is provided with a through hole, the shoulder of the long shaft sleeve (4) is slidably connected to the outer bottom surface of the ring frame (6-1), and passes through the ring frame (6-1), the friction ring (16), the spiral seat (3), and the ring sleeve (15) in sequence, and the ring frame (6-1), the friction ring (16), the spiral seat (3), the ring sleeve (15) and the long shaft sleeve ( The end of the long shaft sleeve (4) is connected to the finger seat (2), and the long shaft sleeve (4) is used to drive the finger seat (2) to rotate. The finger seat (2), the ring sleeve (15), and the spiral seat (3) can rotate relatively. The finger seat (2) is provided with a plurality of finger grooves (2-1) evenly distributed in a circumference. The finger grooves (2-1) are provided with a plurality of groups of pin holes (2-2) in a radial direction. A clamping finger (1) is rotatably connected in each finger groove (2-1), and a ball head (2-2) is provided at the end of each clamping finger (1). 1-1), the spiral seat (3) is provided with a plurality of arc grooves (3-1) having the same number as the ball head (1-1), the ball head (1-1) and the arc grooves (3-1) are slidably connected; the spiral seat (3) is connected to the friction ring (16), the friction block (11) is located between the elastic frame (10) and the friction ring (16), the housing of the motor (7) is connected to the frame (6), the inner side wall and the bottom surface of the ring frame (6-1) are slidably connected to the outer side surface of the ring sleeve (15) and the bottom surface of the spiral seat (3), respectively, the ring frame (6-1 ) is provided with a groove (6-2) at the bottom, the elastic frame (10), the friction block (11) and the friction ring (16) are located in the groove (6-2), the inner wall of the groove (6-2) is provided with a through adjusting bolt hole (6-3), the bolt rod of the adjusting bolt (8) passes through the square countersunk hole (6-4) and the adjusting bolt hole (6-3) on the outer bottom surface of the ring frame (6-1) in sequence, penetrates into the groove (6-2) and abuts against one end of the elastic frame (10), and the adjusting bolt (8) is threadedly connected with a fixing nut (9) located in the square countersunk hole (6-4).

2. The portable screw-gripping device with adjustable opening and clamping force according to claim 1, characterized in that: The front end of the long shaft sleeve (4) passes through the central through hole at the bottom of the ring frame (6-1) and is inserted into the inner hole of the finger seat (2), and the front end of the long shaft sleeve (4) is circumferentially connected to the finger seat (2).

3. The portable screw-gripping device with adjustable opening and clamping force according to claim 2, characterized in that: The inner hole of the long shaft sleeve (4) comprises a shaft sleeve mounting hole, a countersunk hole and a bolt hole which are connected in sequence; the output shaft (7-1) of the motor (7) is connected to the shaft sleeve (5), and the shaft sleeve (5) is connected to the shaft sleeve mounting hole of the long shaft sleeve (4); the bolt head of the long bolt (12) is located in the countersunk hole, and the bolt rod of the long bolt (12) passes through the bolt hole of the long shaft sleeve (4) and the inner hole of the finger seat (2) in sequence and is connected to the nut (13); the nut (13) is located in the central countersunk hole (2-3) of the finger seat (2).

4. The portable screw-gripping device with adjustable opening and clamping force according to claim 1, characterized in that: The clamping fingers (1) are three in number, and the finger seat (2) is provided with three finger grooves (2-1) evenly distributed in a circumference, each finger groove (2-1) has a plurality of groups of pin holes (2-2), and the clamping fingers (1) are rotatably connected to one of the groups of pin holes (2-2) via a pin (14).

5. The portable screw-gripping device with adjustable opening and clamping force according to claim 1, characterized in that: The center of the spiral seat (3) is provided with a waist-shaped hole for passing the inner hole of the long shaft sleeve (4) and the circumferential connection friction ring (16), and the waist-shaped hole is a countersunk hole. There are three arc grooves (3-1) on the spiral seat (3), and one end of each arc groove (3-1) is close to the inner hole of the spiral seat (3), and the other end is close to the outer circumferential surface of the spiral seat (3).

6. The portable screw-gripping device with adjustable opening and clamping force according to claim 1, characterized in that: The housing of the motor (7) is fixedly connected to the frame (6) by means of bolts passing through the motor mounting holes (6-6).

7. The portable screw-gripping device with adjustable opening and clamping force according to claim 1, characterized in that: The friction block (11) is an arc-shaped friction block, the fixing nut (9) is a square nut, and the adjusting bolt (8) and the fixing nut (9) rotate relative to each other while moving axially in the adjusting bolt hole (6-3).

8. The portable screw-gripping device with adjustable opening and clamping force according to claim 7, characterized in that: There are two friction blocks (11), two adjusting bolts (8) and two fixing nuts (9).

9. The portable screw-gripping device with adjustable opening and clamping force according to claim 1, characterized in that: The clamping surfaces of the clamping fingers (1) and the upper surface of the finger seat (2) are covered with flexible material (17).

10. The portable screw-gripping device with adjustable opening and clamping force according to claim 4, characterized in that: The clamping force of the clamping fingers can be adjusted by changing the length of the clamping finger portion between the pin and the ball head.

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