Multi-joint tandem type flexible mechanical arm

Abstract

The invention relates to the technical field of mechanical arms, in particular to a multi-joint tandem type flexible mechanical arm which comprises two joint end plates, a plurality of air bags are arranged between the two joint end plates, a first connecting rod is fixedly installed on one end plate, a ball seat is installed on the first connecting rod, a second connecting rod is installed on the other joint end plate, and the ball seat is connected with the second connecting rod. A ball head is mounted at one end of the second connecting rod, a sliding groove is formed in the first connecting rod, a mounting plate is slidably mounted in the sliding groove, a plurality of reinforcing cilia are fixedly mounted on the mounting plate, and inserting holes matched with the reinforcing cilia are formed in the ball head. According to the mechanical arm, the reinforcing cilia and the inserting holes are arranged, the reinforcing cilia are inserted into the inserting holes, the strength of the connecting position of the first connecting rod and the second connecting rod is complemented through the rigidity of the reinforcing cilia, and the load capacity of the whole mechanical arm is improved; and the flexibility of the mechanical arm can be recovered only by using the first reset spring to drive the reinforcing cilia to reset.

Description

Technical Field

[0001] The present invention relates to the technical field of robotic arms, and specifically to a multi-joint series flexible robotic arm. Background Art

[0002] A robotic arm is a complex system with high precision, multiple inputs and outputs, high nonlinearity, and strong coupling. It can imitate the human arm to grasp an object and send the object to a designated place, or drive a tool to complete a specified operation along a certain path in three-dimensional space. With the development of robotic arms, robotic arms have gradually replaced some repetitive labor that requires manual processing and installation, improving production efficiency while ensuring the stability of product quality.

[0003] Among them, most robotic arms can be called flexible robotic arms. Flexible robotic arms have higher flexibility and can complete more actions in three-dimensional space. Some flexible robotic arms are designed by imitating the structures of snakes and octopus tentacles, enabling them to enter narrow and variable spaces like snakes and octopus tentacles, providing great help for the exploration and rescue of narrow spaces.

[0004] The principle of such snake-shaped and tentacle-shaped robotic arms is usually to connect multiple joints in series, and then use steel wires and servos to control each joint. There are also some robotic arms that use the method of inflating and deflating airbags to control the posture of the robotic arm, enabling the robotic arm to flexibly bend in three-dimensional space. Therefore, such robotic arms are also called multi-joint series flexible robotic arms. However, although the existing multi-joint series flexible robotic arms have high flexibility, weak load capacity is a major problem. For this reason, a large number of studies have been conducted in the prior art on how to improve their load capacity.

[0005] For example, the Chinese invention patent with the application number: CN201810694731.9 and the name "Pneumatic Controlled Rigid-Flexible Coupled Modular Soft Robotic Arm" proposed a robotic arm. By fixing structures that radially pull the airbag bodies of the airbag modules, it realizes the coupled movement of the airbag bodies of each airbag module at different axial segment positions and improves the load capacity of the robotic arm, facilitating the movement of carrying heavier objects. And the Chinese invention patent with the application number: CN202310144661.0 and the name "A Flexible Robotic Arm Based on the Coupling of Shape Memory Alloy and Pneumatic Artificial Muscle" further optimized the above pneumatic controlled rigid-flexible coupled modular soft robotic arm. By setting a central rod in the center of the robotic arm, the material of the central rod is nickel-titanium alloy with shape memory function, and its stiffness is enhanced after heating by electricity, further improving the stability of the flexible robotic arm.

[0006] The above patent adds a central rod made of shape memory alloy. The central rod can be heated by electricity to increase its stiffness and can return to its original softness after cooling. This not only maintains the flexibility of the robotic arm when it bends and deforms but also improves the stiffness of the robotic arm when it is loaded to ensure the load capacity of the robotic arm.

[0007] However, although the central rod made of shape memory alloy can improve the load capacity of the robotic arm by heating through electricity, if the posture of the robotic arm needs to be readjusted at this time, then the central rod needs to be cooled down to restore its original softness to facilitate the posture adjustment of the robotic arm. However, the cooling speed of the central rod is much slower than the heating speed. Moreover, when the robotic arm adjusts its posture, multiple joints may need to be adjusted sequentially in order, which will result in a longer time required for the robotic arm to readjust its posture, and thus a longer time required for production operations. In addition, the long-term heating of the central rod is also likely to affect the service life of other parts of the robotic arm, such as causing rubber and plastic parts to age easily.

[0008] Therefore, a multi-joint series flexible robotic arm is proposed. Summary of the Invention

[0009] The purpose of the present invention is to provide a multi-joint series flexible robotic arm, which can improve the load strength of the multi-joint series flexible robotic arm while ensuring the response speed of the robotic arm posture adjustment.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A multi-joint series flexible robotic arm includes two joint end plates. The joint end plates are both circular. The two joint end plates are coaxially and parallelly spaced apart. A plurality of air bags are arranged between the two joint end plates. Both ends of each air bag are respectively fixed on the two joint end plates. Each air bag is communicated with an external air supply component. The plurality of air bags are circumferentially distributed between the two joint end plates with the axis of the joint end plate as the reference. A first connecting rod is fixedly installed on one of the end plates. The first connecting rod is located between the two joint end plates and is coaxially arranged with the joint end plate where it is located. A ball seat is fixedly installed at the free end of the first connecting rod. A second connecting rod is fixedly installed on the other joint end plate opposite to the first connecting rod. The second connecting rod is also located between the two joint end plates and is coaxially arranged with the joint end plate where it is located. A ball head is fixedly installed at one end of the second connecting rod facing the first connecting rod. The ball head is rotatably installed in the ball seat. A chute is opened inside the first connecting rod. The chute is communicated with the ball seat. An installation plate is slidably installed inside the chute. A plurality of reinforcing cilia are fixedly installed on the installation plate. Plugging holes that cooperate with the reinforcing cilia are opened on the ball head. The chute is communicated with the external air supply component. When the chute is inflated, the installation plate drives the reinforcing cilia to move towards the plugging holes and insert into the plugging holes. A return spring for driving the installation plate to reset is also installed inside the chute.

[0012] The robotic arm takes the two joint end plates and the air bags between the joint end plates as one joint. The air bags adjust the included angle between the two joint end plates by inflating and deflating, so as to adjust the postures of each joint, and further control the posture of the entire robotic arm.

[0013] The first connecting rod and the second connecting rod are arranged between the joint end plates. The first connecting rod and the second connecting rod are rotatably connected by the ball head and the ball seat, which improves the joint strength of the robotic arm while ensuring a large rotation angle of the robotic arm joint and ensuring the flexibility of the robotic arm. After the air bag adjusts the posture of the joint, the external construction component inflates the inside of the chute, which can push the installation seat inside the chute to move towards the plugging holes and make the reinforcing cilia insert into the inside of the plugging holes. After the reinforcing cilia insert into the inside of the plugging holes, the air pressure inside the chute remains unchanged. At this time, the reinforcing cilia support the inner wall of the plugging hole from the inside of the plugging hole, connecting the first connecting rod and the second connecting rod, and providing resistance when the included angle between the first connecting rod and the second connecting rod changes, so as to improve the rigidity of a single joint of the robotic arm and further improve the load strength of the robotic arm.

[0014] When the joints of the robotic arm need to be readjusted during use, the gas inside the slide can be discharged to reduce the air pressure inside the slide. The first recovery spring will pull the reinforcing cilia toward the inside of the slide and cause the reinforcing cilia to detach from the socket. At this time, the reinforcing cilia no longer support the second connecting rod from the inside of the socket, and no longer hinder the angle change between the first connecting rod and the second connecting rod. By adjusting the airbag, the angle between the two joint end plates can be easily adjusted, thereby quickly adjusting the posture of the joint.

[0015] Preferably, a push plate is slidably installed inside the plug hole, and a plurality of connecting cilia are fixedly installed on one end of the push plate facing the mounting plate. An air cavity is also provided inside the first connecting rod, and the air cavity is connected to the external air supply component. A sealing block is slidably installed inside the air cavity, and a fixing rod is provided between the sealing block and the push plate. The two ends of the fixing rod are respectively fixedly connected to the sealing block and the push plate. When the air cavity is inflated, the push plate moves along the plug hole toward the mounting plate. A second reset spring is also provided inside the air cavity to drive the sealing block to reset.

[0016] By inflating the air cavity, the sealing block is pushed and the push plate and the connecting cilia are pushed toward the mounting plate, so that the connecting cilia move toward the reinforcing cilia, and finally the connecting cilia and the reinforcing cilia are staggered and plugged in. The friction between the connecting cilia and the reinforcing cilia makes the connecting cilia and the plugged cilia connected into one strand, and the connecting cilia fill the gaps with the reinforcing cilia, thereby further improving the load strength of the joint.

[0017] Furthermore, when the second link is no longer coaxial with the first link, that is, when an angle is formed between the second link and the first link, the reinforcing hairs may not be fully inserted into the socket. This may cause the strength of the reinforcing hairs as a bridge connecting the first and second links to decrease, ultimately making the load strength of the robotic arm joint less than expected. However, after the connecting hairs are provided, even if the reinforcing hairs cannot be fully inserted into the socket, the connecting hairs will extend from the socket and insert into the connecting hairs. At this time, the friction between the connecting hairs and the reinforcing hairs, as well as the stiffness of the reinforcing hairs and the connecting hairs themselves, can increase the overall stiffness of the robotic arm joint, thereby increasing the load strength of the robotic arm.

[0018] Like the reinforcing cilia, when the air pressure inside the air cavity decreases, the connecting cilia will be pulled toward the air cavity by the second reset spring and reset, so that the reinforcing cilia are separated from the connecting cilia, facilitating the posture adjustment of the robotic arm joint.

[0019] Preferably, one end of the ball head facing the first connecting rod is provided with a first plane, and a plurality of supplementary cilia are arranged on the first plane, and the plurality of supplementary cilia are evenly distributed on the first plane. When an included angle is formed between the first connecting rod and the second connecting rod and the reinforcing cilia cannot be completely inserted into the insertion hole, the supplementary cilia can be inserted in a staggered manner with the reinforcing cilia. Through the friction force between the supplementary cilia and the reinforcing cilia and the stiffness of the supplementary cilia and the reinforcing cilia themselves, a resistance is provided for the deflection between the first connecting rod and the second connecting rod, further improving the load strength of the robotic arm.

[0020] Preferably, a plurality of locking grooves are also formed in the ball head. The locking grooves are all perpendicular to the insertion hole. The plurality of locking grooves are circumferentially and evenly distributed on the ball head with the axis of the second connecting rod as a reference. The locking grooves penetrate through the outer surface of the ball head and communicate with the insertion hole. An extrusion block is slidably installed in the locking groove. A plurality of arc-shaped plates are arranged in the insertion hole corresponding to the plurality of locking grooves. The arc-shaped plates are all made of elastic metal materials, and the arc-shaped plates all protrude towards the axis direction of the insertion hole. The extrusion blocks are respectively fixedly connected to the arc-shaped plates in the corresponding locking grooves.

[0021] Using the pressure inside the air cavity, during the movement of the push plate towards the mounting plate, when the push plate passes through the arc-shaped plate, it squeezes the arc-shaped plate and pushes the extrusion block along the locking groove in a direction away from the axis of the second connecting rod. The extrusion block is pushed towards the side wall of the ball seat, and the extrusion block is in contact with the inner side wall of the ball seat, increasing the friction force between the extrusion block and the inner side wall of the ball seat. The friction force between the extrusion block and the inner side wall of the ball seat is used to further hinder the deflection between the first connecting rod and the second connecting rod, thereby further improving the load capacity of the robotic arm.

[0022] Preferably, the mounting plate includes a fixing ring and a deformation piece. The deformation piece is made of soft rubber. The deformation piece is fixedly installed on the inner ring of the fixing ring and completely closes the inner ring of the fixing ring. The reinforcing cilia are fixedly installed on the deformation piece. The deformation piece can deform when subjected to the gas pressure inside the sliding groove, enabling the reinforcing cilia to better contact the connecting cilia and the supplementary cilia, thereby further improving the load strength of the robotic arm.

[0023] Preferably, a plurality of annular grooves are provided on the ball seat. A plurality of protrusions for being clamped into the annular grooves are arranged at one end of the extrusion block away from the insertion hole. The protrusions are evenly distributed on the end surface of the extrusion block. When the extrusion block is pushed along the locking groove by the push plate and the arc-shaped plate, the protrusions move in a direction away from the insertion hole following the extrusion block, and finally the protrusions are clamped into the annular grooves to cooperate with the reinforcing cilia, the connecting cilia, and the supplementary cilia to jointly limit the ball head, preventing the ball head from further deflecting, thereby preventing the first connecting rod and the second connecting rod from deflecting, and strengthening the load capacity of the joint of the robotic arm.

[0024] Preferably, a relief spring is arranged between the extrusion block and the arc-shaped plate. One end of the relief spring is fixedly connected to the extrusion block, and the other end is fixedly connected to the arc-shaped plate. The relief spring enables a certain compression space to exist between the arc-shaped plate and the extrusion block when the convex block fails to be inserted into the annular groove, avoiding the situation where the push plate cannot pass smoothly through the protruding position of the arc-shaped plate, ensuring that even if the convex block fails to be inserted into the annular groove smoothly, the push plate can still squeeze the arc-shaped plate to deform and pass through the arc-shaped plate, guaranteeing the operating stability of the device.

[0025] It should be noted that when the convex block is stuck into the annular groove, the convex block will not be subjected to the force along the locking groove direction when providing resistance to the angular deflection between the first connecting rod and the second connecting rod. Therefore, even if a relief spring is arranged between the extrusion block and the arc-shaped plate, it will not affect the locking of the convex block to the first connecting rod and the second connecting rod.

[0026] Preferably, a rubber part is arranged at the end of the convex block away from the insertion hole. When the convex block fails to be stuck into the annular groove, the rubber part can improve the friction between the convex block and the inner wall of the ball seat, and then improve the resistance received when the first connecting rod and the second connecting rod are bent through this friction, thereby improving the load strength of the robotic arm.

[0027] Preferably, conical pointed parts are arranged at the free ends of the reinforcing cilia, connecting cilia and supplementary cilia. The arrangement of the pointed parts facilitates the mutual avoidance when the cilia are misaligned and inserted, avoiding the situation where the cilia cannot be misaligned and inserted due to alignment, and guaranteeing the operating stability of the device.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. A multi-joint series flexible robotic arm designed by the present invention, through the arrangement of the reinforcing cilia and the insertion holes, after the robotic arm adjusts its posture through the airbag, the reinforcing cilia are inserted into the insertion holes, and the rigidity of the reinforcing cilia is used to supplement the strength at the connection position of the first connecting rod and the second connecting rod, thereby improving the load capacity of the entire robotic arm. When it is necessary to change the posture, only need to use the first return spring to drive the reinforcing cilia to reset to restore the flexibility of the robotic arm.

[0030] 2. A multi-joint series flexible robotic arm designed by the present invention is also provided with connecting cilia and supplementary cilia. After the robotic arm joint is bent and the insertion hole and the reinforcing cilia are misaligned, the connecting cilia extend out of the insertion hole to connect with the reinforcing cilia. At the same time, the supplementary cilia can also connect with the reinforcing cilia, further ensuring the load capacity after the robotic arm posture adjustment is completed.

[0031] 3. A multi-joint series flexible robotic arm designed by the present invention further comprises a pressing block. The pushing plate drives the connecting cilia to move, which in turn drives the pressing block, causing the end face of the pressing block to press against the inner wall of the ball seat. By increasing the frictional force between the ball seat and the pressing block, the load capacity of the robotic arm joint is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a three-dimensional structural schematic diagram of the present invention;

[0033] Figure 2 is a front view of a single robotic arm joint in the present invention;

[0034] Figure 3 In the present invention Figure 2 is a cross-sectional view taken along line A-A;

[0035] Figure 4 In the present invention Figure 3 is an enlarged view at position B;

[0036] Figure 5 In the present invention Figure 4 is an enlarged view at position C;

[0037] Figure 6 is a schematic diagram of the state when the first connecting rod and the second connecting rod are not coaxial in the present invention;

[0038] Figure 7 In the present invention Figure 6 is an enlarged view at position D;

[0039] Figure 8 is a schematic diagram of the state when the deformation sheet is deformed under air pressure in the present invention.

[0040] In the figures: 1, joint end plate; 2, airbag; 3, first connecting rod; 4, ball seat; 5, second connecting rod; 6, ball head; 7, sliding groove; 8, mounting plate; 801, fixing ring; 802, deformation sheet; 9, reinforcing cilia; 10, insertion hole; 11, first return spring; 12, pushing plate; 13, connecting cilia; 14, air chamber; 15, sealing block; 16, fixing rod; 17, second return spring; 18, first plane; 19, supplementary cilia; 20, locking groove; 21, pressing block; 22, arc plate; 23, annular groove; 24, convex block; 25, avoidance spring; 26, rubber part; 27, pointed cone part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] Please refer to Figures 1 to 8 , the present invention provides a multi-joint series flexible robotic arm, and the technical solution is as follows:

[0042] A multi-joint series flexible robotic arm, referring to Figures 1 to 3, the robotic arm is composed of multiple joints connected in series. Each joint includes two joint end plates 1, both of which are circular. The two joint end plates 1 are coaxial and arranged in parallel at intervals. A plurality of air bags 2 are arranged between the two joint end plates 1. Both ends of each air bag 2 are respectively fixed on the two joint end plates 1. Each air bag 2 is communicated with an external air supply component, and each air bag 2 is independently supplied with air. A plurality of air bags 2 are circumferentially and evenly distributed between the two joint end plates 1 with the axis of the joint end plate 1 as the reference. A first connecting rod 3 is fixedly installed on one of the end plates. The first connecting rod 3 is located between the two joint end plates 1 and is coaxial with the joint end plate 1 where it is located. A ball seat 4 is fixedly installed at the free end of the first connecting rod 3. A second connecting rod 5 is fixedly installed on the other joint end plate 1 opposite to the first connecting rod 3. The second connecting rod 5 is also located between the two joint end plates 1 and is coaxial with the joint end plate 1 where it is located. A ball head 6 is fixedly installed at one end of the second connecting rod 5 facing the first connecting rod 3. The ball head 6 is rotatably installed in the ball seat 4. A plug hole 10 is formed in the ball head 6, and the plug hole 10 is coaxial with the second connecting rod 5.

[0043] Reference Figure 3 , Figure 4 and Figure 5 , one end of the ball head 6 facing the first connecting rod 3 is provided with a first plane 18. A plurality of supplementary cilia 19 are arranged on the first plane 18. The supplementary cilia 19 are made of elastic metal material or plastic material. When setting, the diameter range of the supplementary cilia 19 is 0.3mm - 1mm, and the density is about 30 - 40 per square centimeter. A plurality of supplementary cilia 19 are evenly distributed on the first plane 18. A push plate 12 is slidably installed inside the plug hole 10. A plurality of connecting cilia 13 are fixedly installed at one end of the push plate 12 facing the mounting plate 8. The diameter of the connecting cilia 13 is the same as that of the supplementary cilia 19, and the density is also the same as that of the supplementary cilia 19. An air cavity 14 is also formed inside the first connecting rod 3. The air cavity 14 is communicated with an external air supply component. The air supply component can be an air pump or a gas storage tank filled with high-pressure gas, or other devices or components that can supply air inside the chute 7. A sealing block 15 is slidably installed inside the air cavity 14, and the sealing block 15 is slidably and sealedly connected with the air cavity 14. A fixing rod 16 is arranged between the sealing block 15 and the push plate 12. Both ends of the fixing rod 16 are respectively fixedly connected with the sealing block 15 and the push plate 12. When the air cavity 14 is inflated, the push plate 12 moves along the plug hole 10 towards the mounting plate 8. A second return spring 17 for driving the sealing block 15 to reset is also arranged inside the air cavity 14.

[0044] Reference Figure 4 and Figure 5, a plurality of locking grooves 20 are further formed in the ball head 6. The locking grooves 20 are all perpendicular to the insertion holes 10. The plurality of locking grooves 20 are circumferentially and uniformly distributed on the ball head 6 with the axis of the second connecting rod 5 as the reference. The locking grooves 20 all penetrate through the outer surface of the ball head 6 and communicate with the insertion holes 10. An extrusion block 21 is slidably installed inside the locking groove 20. A relief spring 25 is arranged between the extrusion block 21 and the arc-shaped plate 22. One end of the relief spring 25 is fixedly connected to the extrusion block 21, and the other end is fixedly connected to the arc-shaped plate 22. A plurality of arc-shaped plates 22 are arranged in the insertion holes 10 corresponding to the plurality of locking grooves 20. The arc-shaped plates 22 are all made of elastic metal materials. One end of the arc-shaped plate 22 close to the air cavity 14 is fixed to the insertion hole 10, and the other end is a free end. The arc-shaped plates 22 all protrude towards the axis direction of the insertion hole 10.

[0045] Reference Figure 5 , a plurality of annular grooves 23 are arranged on the ball seat 4. A plurality of protrusions 24 for being clamped into the annular grooves 23 are arranged at one end of the extrusion block 21 away from the insertion hole 10. The protrusions 24 are evenly distributed on the end surface of the extrusion block 21. A rubber part 26 is arranged at one end of the protrusion 24 away from the insertion hole 10

[0046] Reference Figure 3 , Figure 4 , a chute 7 is formed inside the first connecting rod 3. The chute 7 communicates with the ball seat 4. A mounting plate 8 is slidably installed inside the chute 7. The mounting plate 8 includes a fixed ring 801 and a deformation piece 802. The deformation piece 802 is made of soft rubber. The deformation piece 802 is fixedly installed on the inner ring of the fixed ring 801 and completely closes the inner ring of the fixed ring 801. The fixed ring 801 is slidably and sealingly connected with the chute 7. A plurality of reinforcing cilia 9 are fixedly installed on the deformation piece 802. The diameter of the reinforcing cilia 9 is also the same as that of the supplementary cilia 19, and the density is also the same as that of the supplementary cilia 19, which is convenient for filling the gaps when being inserted with each other. The chute 7 also communicates with an external air supply component. The air supply component can be an air pump or a gas storage tank filled with high-pressure gas, or other devices or components that can supply air to the inside of the chute 7.

[0047] When the robotic arm is installed, reference Figure 1 , a plurality of joints are arranged in sequence, and two adjacent joint end plates 1 are fixedly connected together by bolts, so as to be connected in series into a multi-joint flexible robotic arm.

[0048] During the use of the robotic arm, by adjusting the inflation amount of the single airbag 2 on each joint, the angle between the two joint end plates 1 on each joint is adjusted, so as to adjust the posture of the joints of the robotic arm.

[0049] After the posture of a single joint of the robotic arm is adjusted, reference Figure 3 and Figure 4The air supply assembly first inflates the interior of the chute 7. The increased air pressure inside the chute 7 pushes the mounting plate 8 toward the second connecting rod 5. The first return spring 11 is stretched, and the reinforcing hairs 9 on the mounting plate 8 extend into the interior of the ball seat 4 and ultimately into the socket 10. Once inserted into the socket 10, the reinforcing hairs 9 provide support for the inner wall of the socket 10 through their own rigidity, improving the load-carrying effect of the robotic arm.

[0050] At this time, refer to Figure 4 , the air supply assembly is controlled to supply air to the air cavity 14 on the second connecting rod 5. The air pressure inside the air cavity 14 increases, and the air pressure pushes the sealing block 15 toward the direction of the first connecting rod 3, and the second return spring 17 is stretched. Because the push plate 12 and the sealing block 15 are fixedly connected by the fixing rod 16, the push plate 12 will also be pushed toward the direction of the first connecting rod 3. The end of the connecting cilia 13 on the push plate 12 will eventually extend out of the plug hole 10, and the connecting cilia 13 will come into contact with the reinforcing cilia 9. A large number of connecting cilia 13 and reinforcing cilia 9 are misaligned and plugged into each other, filling the inside of the plug hole 10. The reinforcing cilia 9 and connecting cilia 13 also enhance the load capacity of the joints of the manipulator through their own rigidity. After the posture of the manipulator is adjusted, it prevents further deflection between the first connecting rod 3 and the second connecting rod 5, thereby maintaining the stability of the manipulator. Among them, the friction between the reinforcing cilia 9 and the connecting cilia 13 can ensure the stability of the connection between the reinforcing cilia 9 and the connecting cilia 13.

[0051] When the air cavity 14 is not inflated, Figure 4 and Figure 5 The arc plate 22 protrudes toward the axis direction of the plug hole 10 under the action of its own elastic force, and the arc plate 22 drives the avoidance spring 25 and the extrusion block 21 and the protrusion 24 to be stored in the locking groove 20.

[0052] In the process of the air pressure pushing the sealing block 15 toward the direction of the first connecting rod 3, Figure 4 and Figure 5 When the push plate 12 passes the curved plate 22, it squeezes the curved plate 22, causing it to deform and move out of the way. This deformation of the curved plate 22 drives the avoidance spring 25 and the extrusion block 21 along the locking groove 20, away from the insertion hole 10. The protrusion 24 at the front end of the extrusion block 21 abuts against the inner wall of the ball seat 4, increasing the resistance to rotation between the ball head 6 and the ball seat 4, further improving the load capacity of the robot arm.

[0053] refer to Figure 5When the bump 24 at the front end of the extrusion block 21 is exactly aligned with the annular groove 23, the bump 24 snaps into the annular groove 23, which can further prevent the first link 3 and the second link 5 from deflecting and further improve the load capacity of the robotic arm. For the bumps 24 that fail to align with the annular groove 23, under the double extrusion of the inner wall of the ball seat 4 and the arc-shaped plate 22, the avoidance spring 25 will be compressed to ensure that the push plate 12 can smoothly drive the connecting cilia 13 to extend towards the first link 3, guaranteeing the operation stability of the device.

[0054] When the first link 3 and the second link 5 are not coaxial, referring to Figure 6 and Figure 7 , some of the reinforcing cilia 9 will not be able to smoothly insert into the insertion holes 10. At this time, some of the reinforcing cilia 9 will be misaligned and inserted with the supplementary cilia 19 on the first plane 18. The misaligned insertion between the reinforcing cilia 9 and the supplementary cilia 19 can also provide support for the ball head 6 to prevent the first link 3 and the second link 5 from deflecting, thereby improving the load capacity of the robotic arm. In addition, the connecting cilia 13 extending from the insertion holes 10 can also be misaligned and inserted with the reinforcing cilia 9 that fail to extend into the insertion holes 10, and the load capacity of the robotic arm is improved through the frictional force between the reinforcing cilia 9 and the connecting cilia 13.

[0055] Meanwhile, referring to Figure 8 , when the first link 3 and the second link 5 are not coaxial, due to the influence of the air pressure inside the sliding groove 7, the deformation piece 802 will also be squeezed and deformed, enabling the reinforcing cilia 9 to adjust its direction and better contact with the connecting cilia 13 and the supplementary cilia 19.

[0056] When it is necessary to re-adjust the posture of the robotic arm, referring to Figure 3 , Figure 4 [[ID=1�]]and Figure 5 , first, the gas inside the air cavity 14 is discharged outside the air cavity 14, causing the air pressure inside the air cavity 14 to drop. The second return spring 17 pulls the sealing block 15 and the push plate 12 to return inside the air cavity 14, and the connecting cilia 13 are separated from the reinforcing cilia 9. The arc-shaped plate 22 returns under its own elastic force and pulls the extrusion block 21 to return. Subsequently, the gas inside the sliding groove 7 is discharged outside the sliding groove 7. After the air pressure inside the sliding groove 7 decreases, the mounting plate 8 is pulled to return inside the sliding groove 7 under the action of the first return spring 11, and the reinforcing cilia 9 are retracted inside the sliding groove 7. At this time, the posture of the robotic arm can be continuously adjusted by controlling the inflation and deflation of the airbag 2.

[0057] In addition, referring to Figure 7 and Figure 8 , in order to enable the reinforcing cilia 9, the connecting cilia 13, and the supplementary cilia 19 to be better misaligned and inserted during the insertion process, conical pointed parts 27 can be provided at the free ends of the reinforcing cilia 9, the connecting cilia 13, and the supplementary cilia 19.

[0058] The above has described in detail a specific embodiment of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiment. For those skilled in the art, without departing from the principles and ideas of the present invention, various changes, modifications, substitutions, and variations made to these embodiments should still fall within the protection scope of the present invention.

Claims

1. A multi-joint series flexible robotic arm, comprising two joint end plates (1), both of the joint end plates (1) being circular. A plurality of air bags (2) are arranged between the two joint end plates (1), and the air bags (2) adjust the included angle between the two joint end plates (1) by inflating and deflating. It is characterized in that, One of the joint end plates (1) is fixedly installed with a first connecting rod (3). A ball seat (4) is fixedly installed at the free end of the first connecting rod (3). Another joint end plate (1) opposite to the first connecting rod (3) is fixedly installed with a second connecting rod (5). A ball head (6) is fixedly installed at one end of the second connecting rod (5) facing the first connecting rod (3). The ball head (6) is rotatably installed in the ball seat (4). A chute (7) is formed inside the first connecting rod (3). The chute (7) communicates with the ball seat (4). A mounting plate (8) is slidably installed inside the chute (7). A plurality of reinforcing cilia (9) are fixedly installed on the mounting plate (8). A plugging hole (10) which is matched with the reinforcing cilia (9) is formed on the ball head (6). The chute (7) communicates with an external air supply assembly. When the chute (7) is inflated, the mounting plate (8) drives the reinforcing cilia (9) to move towards the plugging hole (10) and insert into the plugging hole (10). A first return spring (11) for driving the mounting plate (8) to reset is further installed inside the chute (7).

2. The multi-joint series flexible robotic arm according to claim 1, characterized in that, A push plate (12) is slidably installed inside the plugging hole (10). A plurality of connecting cilia (13) are fixedly installed at one end of the push plate (12) facing the mounting plate (8). An air cavity (14) is further formed inside the first connecting rod (3). The air cavity (14) communicates with an external air supply assembly. A sealing block (15) is slidably installed inside the air cavity (14). A fixing rod (16) is arranged between the sealing block (15) and the push plate (12). Two ends of the fixing rod (16) are respectively fixedly connected with the sealing block (15) and the push plate (12). When the air cavity (14) is inflated, the push plate (12) moves along the plugging hole (10) towards the mounting plate (8). A second return spring (17) for driving the sealing block (15) to reset is further arranged inside the air cavity (14).

3. A multi-joint series flexible robotic arm according to claim 2, characterized in that, One end of the ball head (6) facing the first connecting rod (3) is provided with a first plane (18). A plurality of supplementary cilia (19) are arranged on the first plane (18). The plurality of supplementary cilia (19) are evenly distributed on the first plane (18).

4. A multi-joint series flexible robotic arm according to claim 2, characterized in that, A plurality of locking grooves (20) are further formed in the ball head (6). The locking grooves (20) are all perpendicular to the insertion holes (10). The plurality of locking grooves (20) are circumferentially and uniformly distributed on the ball head (6) with the axis of the second connecting rod (5) as a reference. The locking grooves (20) penetrate through the outer surface of the ball head (6) and communicate with the insertion holes (10). An extrusion block (21) is slidably installed inside the locking grooves (20). A plurality of arc-shaped plates (22) are arranged in the insertion holes (10) corresponding to the plurality of locking grooves (20). The arc-shaped plates (22) are all made of elastic metal materials, and the arc-shaped plates (22) all protrude towards the axis direction of the insertion holes (10). The extrusion blocks (21) are fixedly connected to the arc-shaped plates (22) in the corresponding locking grooves (20) respectively. When the push plate (12) moves towards the mounting plate (8), the push plate (12) extrudes the arc-shaped plates (22) and pushes the extrusion blocks (21) along the locking grooves (20) towards the direction away from the axis of the second connecting rod (5).

5. A multi-joint series flexible robotic arm according to claim 3, wherein, The mounting plate (8) includes a fixing ring (801) and a deformation sheet (802). The deformation sheet (802) is made of soft rubber. The deformation sheet (802) is fixedly installed on the inner ring of the fixing ring (801) and completely closes the inner ring of the fixing ring (801). The reinforcing cilia (9) are fixedly installed on the deformation sheet (802).

6. A multi-joint series flexible robotic arm according to claim 4, characterized in that, A plurality of annular grooves (23) are formed on the ball seat (4). A plurality of convex blocks (24) for being clamped into the annular grooves (23) are arranged at one end of the extrusion block (21) away from the insertion hole (10). The convex blocks (24) are uniformly distributed on the end surface of the extrusion block (21).

7. A multi-joint series flexible robotic arm according to claim 6, characterized in that, A relief spring (25) is arranged between the extrusion block (21) and the arc-shaped plate (22). One end of the relief spring (25) is fixedly connected to the extrusion block (21), and the other end is fixedly connected to the arc-shaped plate (22).

8. The multi-joint series flexible robotic arm according to claim 6, characterized in that, A rubber part (26) is arranged at one end of the convex block (24) away from the insertion hole (10).

9. The multi-joint series flexible robotic arm according to claim 3, characterized in that, Conical pointed parts (27) are arranged at the free ends of the reinforcing cilia (9), the connecting cilia (13) and the supplementary cilia (19).

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