A mobile variable stiffness device

Abstract

The present invention discloses a mobile variable stiffness device, comprising a shell assembly, a variable stiffness assembly, and a drive assembly. The shell assembly comprises an outer shell, the outer shell being sealed, and a movable cavity being sealed within the outer shell. The variable stiffness assembly comprises a variable stiffness module, the variable stiffness module being sealed, and a sealed cavity being provided within the variable stiffness module, the sealed cavity being filled with granular materials, and the variable stiffness module being arranged within the movable cavity. The drive assembly comprises a first air supply pipe connected to an external air pump, a second air supply pipe, and a variable stiffness air supply pipe, the first air supply pipe being connected to the first air cavity, the second air supply pipe being connected to the second air cavity, and the variable stiffness air supply pipe being connected to the sealed cavity. By adopting the present invention, the stiffness change and position transfer of the variable stiffness module can be simultaneously achieved, thereby expanding the scope of application. In addition, the structure is simple and easy to control and adjust.

Description

Technical Field

[0001] The present invention relates to the technical field of soft robots, and in particular to a mobile variable stiffness device. Background Art

[0002] Currently, soft robots are widely used in industries such as industry, agriculture, medicine, and the military. Stiffness control of soft robots is a key research direction in the field of soft robots. With the continuous development of society, the application environments and scenarios faced by soft robots are becoming more and more complex, which puts more stringent requirements on the flexibility and mechanical compliance of soft robots. Existing research work applies stiffness control to soft robots. The soft robots are equipped with variable-density fillers. The density of the fillers is changed by magneto- or pneumatic methods, so that the soft robots have the function of changing local stiffness. However, the variable stiffness part of the soft robots is currently limited to certain fixed positions of the soft robots. The variable stiffness part cannot be moved, so that the soft robots can only realize certain single functions. Their adaptability to scenarios is relatively low, which limits the robot's ability to complete the task objectives. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a mobile variable stiffness device that can simultaneously achieve stiffness change and position transfer of a variable stiffness module, thereby expanding the scope of application.

[0004] In order to solve the above technical problems, the present invention provides a mobile variable stiffness device, including a shell assembly, a variable stiffness assembly and a drive assembly, the shell assembly includes an outer shell, a first connecting surface and a second connecting surface, the first connecting surface and the second connecting surface are respectively arranged at both ends of the outer shell, the outer shell is sealed, a mobile cavity is sealed in the outer shell, and the variable stiffness assembly is arranged in the mobile cavity.

[0005] The variable stiffness component includes a variable stiffness module, which is sealed. A sealed cavity is provided inside the variable stiffness module, and the sealed cavity is filled with particles. The variable stiffness module is arranged in the movable cavity. The two ends of the variable stiffness module are respectively provided with a top surface and a bottom surface. The top surface, the outer shell and the first connecting surface can form a first air cavity, and the bottom surface, the outer shell and the second connecting surface can form a second air cavity. The variable stiffness module can move back and forth between the first air cavity and the second air cavity.

[0006] The drive assembly includes a first air pipe, a second air pipe and a variable stiffness air pipe connected to an external air pump, the first air pipe is connected to the first air cavity, the second air pipe is connected to the second air cavity, and the variable stiffness air pipe is connected to the sealed cavity.

[0007] As an improvement to the above solution, the first air pipe is connected to the first air cavity through the first connecting surface, the second air pipe is connected to the second air cavity through the second connecting surface, and the variable stiffness air pipe is connected to the sealed cavity through the first connecting surface or the second connecting surface.

[0008] As an improvement of the above solution, the variable stiffness gas pipe is flexibly arranged, the variable stiffness gas pipe is connected to the top surface, the top surface is a curved surface with a concave middle part, or the variable stiffness gas pipe is connected to the bottom surface, the bottom surface is a curved surface with a concave middle part.

[0009] As an improvement of the above solution, the variable stiffness module is divided into a left moving block and a right moving block, the left moving block and the right moving block are isolated from each other by a partition, and both the left moving block and the right moving block are filled with granular members.

[0010] As an improvement to the above solution, the variable stiffness gas pipe is divided into a first branch pipe and a second branch pipe, the first branch pipe is connected to the left moving block through the first connecting surface, and the second branch pipe is connected to the right moving block through the second connecting surface.

[0011] The top surface and the bottom surface are both curved surfaces with a concave center.

[0012] As an improvement of the above solution, the shell assembly also includes a guide tube, which is arranged in the movable cavity and connected between the first connecting surface and the second connecting surface. A through hole is provided in the variable stiffness module, and the through hole passes through the top surface and the bottom surface. The guide tube can pass through the through hole.

[0013] As an improvement to the above solution, the interior of the guide tube is hollow, and the two ends of the guide tube are respectively connected to the first gas pipe and the second gas pipe. A diaphragm is provided in the middle of the guide tube, and the diaphragm divides the guide tube into a first half tube and a second half tube. The first half tube is provided with a first through hole, and the first through hole is only connected to the first air cavity. The second half tube is provided with a second through hole, and the second through hole is only connected to the second air cavity.

[0014] As an improvement to the above solution, the first through hole is arranged at one end of the first half tube close to the first connecting surface. When the variable stiffness module is located at the extreme position of the first air cavity, the first through hole is located between the concave curved surface of the top surface and the first connecting surface.

[0015] The second through hole is provided at one end of the second half tube close to the second connecting surface. When the variable stiffness module is located at the extreme position of the second air cavity, the second through hole is located between the concave curved surface of the bottom surface and the second connecting surface.

[0016] As an improvement of the above solution, the variable stiffness component also includes a plurality of limiting parts, which surround the outer wall of the variable stiffness module, and a plurality of limiting grooves are provided on the inner wall of the shell, and the side parts of the limiting parts can be snapped into the limiting grooves.

[0017] As an improvement of the above-mentioned scheme, the limiting portion includes a first folding block, a second folding block and a hinged end, the first folding block and the second folding block are hinged on the hinged end, the end of the first folding block away from the hinged end is hinged on the outer wall of the variable stiffness module, the end of the second folding block away from the hinged end is hinged on the outer wall of the variable stiffness module, and the hinged end can be stuck in the limiting groove.

[0018] The implementation of the present invention has the following beneficial effects:

[0019] The mobile variable stiffness device of the present invention is provided with a shell component, a variable stiffness component and a driving component, wherein the shell component includes an outer shell, a movable cavity is sealed in the outer shell, a first air cavity and a second air cavity are provided in the movable cavity, the driving component includes a first air pipe and a second air pipe, wherein the first air pipe can inflate the first air cavity, and the second air pipe can inflate the second air cavity, the variable stiffness component includes a variable stiffness module, the variable stiffness module is located in the movable cavity, when the pressure of the first air cavity is greater than the pressure of the second air cavity, the variable stiffness module can move toward the second air cavity, on the contrary, when the pressure of the second air cavity is greater than the pressure of the first air cavity The variable stiffness module can move toward the first air cavity when the pressure is increased, thereby realizing the movement of the variable stiffness module. A sealed cavity is provided in the variable stiffness module, and the sealed cavity is filled with a plurality of granular members. The driving assembly is further provided with a variable stiffness air pipe connected to the sealed cavity. By inputting negative pressure into the sealed cavity through the variable stiffness air pipe, the granular members can be tightly squeezed together, so that the variable stiffness module can increase its stiffness and realize the change of stiffness. Combined with the drive of the first air cavity and the second air cavity, the movement of the variable stiffness module can be realized, thereby realizing the stiffness change and position transfer of the variable stiffness module at the same time, greatly expanding the scope of application of the mobile variable stiffness device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 is a schematic structural diagram of the first embodiment of the mobile stiffness variable device of the present invention before stiffness is changed;

[0021] Figure 2 This is a schematic structural diagram of the first embodiment of the mobile variable stiffness device of the present invention after the stiffness is changed;

[0022] Figure 3 Schematic diagram of the first embodiment of the mobile variable stiffness device of the present invention moving toward the second air cavity;

[0023] Figure 4 Schematic diagram of the first embodiment of the mobile variable stiffness device of the present invention moving toward the first air cavity;

[0024] Figure 5 1 is a schematic structural diagram of the position limiting portion of the second embodiment of the mobile stiffness varying device of the present invention before stiffness variation;

[0025] Figure 6 1 is a schematic structural diagram of the position limiting portion of the second embodiment of the mobile variable stiffness device of the present invention after the stiffness is changed;

[0026] Figure 7 2 is a schematic structural diagram of a third embodiment of the mobile variable stiffness device of the present invention;

[0027] Figure 8 1 is a schematic structural diagram of a fourth embodiment of a mobile variable stiffness device according to the present invention;

[0028] Figure 9 yes Figure 8 Partial view of A in the figure. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that any directional terms such as "up," "down," "left," "right," "front," "back," "inside," and "outside" that appear or will appear herein are based solely on the accompanying drawings and are not intended to limit the present invention.

[0030] See also Figure 1 The first embodiment of the present invention discloses a mobile variable stiffness device, including a shell component 1, a variable stiffness component 2 and a drive component 3. The shell component 1 includes a shell 11, a first connecting surface 12 and a second connecting surface 13. The first connecting surface 12 and the second connecting surface 13 are respectively arranged at both ends of the shell 11. The shell 11 is sealed, and a moving cavity 111 is sealed in the shell 11. The moving cavity 111 is sealed and surrounded by the side wall of the shell 11, the first connecting surface 12 and the second connecting surface 13. The variable stiffness component 2 is arranged in the moving cavity 111, and the moving cavity 111 provides space for the variable stiffness component 2 to move.

[0031] See also Figure 2The variable stiffness component 2 includes a variable stiffness module 21, which is sealed. A sealed cavity 22 is provided inside the variable stiffness module 21, and the sealed cavity 22 is filled with particle parts 23. There are multiple particle parts 23. Under normal conditions, the gaps between the multiple particle parts 23 are large, so that the "density" in the sealed cavity 22 is small, and the stiffness of the variable stiffness module 21 is small. Reducing the gaps between the multiple particle parts 23 can increase the "density" in the sealed cavity 22 and increase the stiffness of the variable stiffness module 21. Therefore, by changing the gaps between the multiple particle parts 23, the stiffness of the variable stiffness module 21 can be changed. The variable stiffness module 21 is arranged in the movable cavity 111. The two ends of the variable stiffness module 21 are respectively provided with a top surface 211 and a bottom surface 212. The top surface 211, the outer shell 11 and the first connecting surface 12 can enclose a first air cavity 14, and the bottom surface 212, the outer shell 11 and the second connecting surface 13 can enclose a second air cavity 15. The variable stiffness module 21 can move back and forth between the first air cavity 14 and the second air cavity 15.

[0032] In order to drive the variable stiffness module 21, the driving assembly 3 includes a first air supply pipe 31, a second air supply pipe 32 and a variable stiffness air supply pipe 33 connected to an external air pump. The first air supply pipe 31 is connected to the first air cavity 14, the second air supply pipe 32 is connected to the second air cavity 15, and the variable stiffness air supply pipe 33 is connected to the sealed cavity 22. Figure 3 When the external air pump inputs positive pressure to the first air cavity 14 through the first air pipe 31, and the external air pump inputs positive pressure to the second air cavity 15 through the second air pipe 32, and the positive pressure of the first air cavity 14 is greater than the positive pressure of the second air cavity 15, the first air cavity 14 will generate a driving force on the top surface 211, driving the variable stiffness module 21 to move toward the second air cavity 15 with a lower pressure. On the contrary, see Figure 4 When the positive pressure of the first air cavity 14 is lower than the positive pressure of the second air cavity 15, the second air cavity 15 will generate a driving force on the top surface 211, driving the variable stiffness module 21 to move toward the first air cavity 14 with a lower pressure. Under the action of the first air pipe 31, the second air pipe 32, the first air cavity 14 and the second air cavity 15, the variable stiffness module 21 can move within the movable cavity 111. The variable stiffness air pipe 33 is connected to the sealed cavity 22. When the variable stiffness air pipe 33 provides negative pressure to the sealed cavity 22, the sealed cavity 22 will shrink, making the gaps between the particle members 23 smaller, thereby achieving the effect of improving the stiffness of the variable stiffness module 21. Moreover, by controlling the magnitude of the negative pressure, the magnitude of the stiffness change can also be controlled.

[0033] Therefore, the beneficial effects of the first embodiment of the present invention are as follows:

[0034] The mobile variable stiffness device of the embodiment of the present invention is provided with a shell component 1, a variable stiffness component 2 and a driving component 3, wherein the shell component 1 includes an outer shell 11, a movable cavity 111 is sealed in the outer shell 11, and a first air cavity 14 and a second air cavity 15 are provided in the movable cavity 111, the driving component 3 includes a first air supply pipe 31 and a second air supply pipe 32, wherein the first air supply pipe 31 can inflate the first air cavity 14, and the second air supply pipe 32 can inflate the second air cavity 15, the variable stiffness component 2 includes a variable stiffness module 21, and the variable stiffness module 21 is located in the movable cavity 111. When the pressure of the first air cavity 14 is greater than the pressure of the second air cavity 15, the variable stiffness module 21 can move toward the second air cavity 15. On the contrary, when the pressure of the second air cavity 15 is greater than the pressure of the second air cavity 15, the variable stiffness module 21 can move toward the second air cavity 15. Due to the pressure of the first air cavity 14, the variable stiffness module 21 can move toward the first air cavity 14, thereby realizing the movement of the variable stiffness module 21. A sealed cavity 22 is provided in the variable stiffness module 21, and the sealed cavity 22 is filled with a plurality of particle members 23. The driving component 3 is also provided with a variable stiffness air pipe 33 connected to the sealed cavity 22. By inputting negative pressure into the sealed cavity 22 through the variable stiffness air pipe 33, the particle members 23 can be tightly squeezed together, so that the variable stiffness module 21 can increase the stiffness and realize the change of stiffness. Combined with the drive of the first air cavity 14 and the second air cavity 15, the movement of the variable stiffness module 21 can be realized, thereby realizing the stiffness change and position transfer of the variable stiffness module 21 at the same time, greatly expanding the scope of application of the mobile variable stiffness device.

[0035] The first air supply pipe 31 is connected to the first air cavity 14 through the first connecting surface 12, and the second air supply pipe 32 is connected to the second air cavity 15 through the second connecting surface 13. The sealed cavity 22 is located in the movable cavity 111. To achieve communication, the variable stiffness air supply pipe 33 passes through the first connecting surface 12 or the second connecting surface 13, so that the variable stiffness air supply pipe 33 is located in the movable cavity 111 and connected to the sealed cavity 22. Furthermore, to enable the variable stiffness module 21 to move between the first air cavity 14 and the second air cavity 15, the length of the variable stiffness air supply pipe 33 is greater than the length of the first air cavity 14 or the second air cavity 15. In order to accommodate the excess length of the variable stiffness air supply pipe 33, the variable stiffness air supply pipe 33 is flexibly configured and can be coiled around one end of the variable stiffness module 21, so that the variable stiffness air supply pipe 33 can move with the variable stiffness module 21 and can be extended or coiled as needed. When the variable stiffness air supply pipe 33 is connected to the top surface 211, the top surface 211 is a curved surface with a concave middle portion, and the variable stiffness air supply pipe 33 can be coiled on the concave curved surface of the top surface 211, or when the variable stiffness air supply pipe 33 is connected to the bottom surface 212, the bottom surface 212 is a curved surface with a concave middle portion, and the variable stiffness air supply pipe 33 can be coiled on the concave curved surface of the bottom surface 212.

[0036] The variable stiffness module 21 can be moved by using the first air cavity 14 and the second air cavity 15. However, it is difficult to achieve a good positioning effect for the variable stiffness module 21 by relying on the air pressure at both ends. Therefore, the mobile variable stiffness device of the present invention also discloses a second embodiment, see Figure 5 and Figure 6 In the second embodiment, to provide a positioning effect for the variable stiffness module 21 after movement, the variable stiffness assembly 2 further includes a plurality of limiting portions 24. The limiting portions 24 surround the outer wall of the variable stiffness module 21. The inner wall of the housing 11 is provided with a plurality of limiting grooves 19. The side portions of the limiting portions 24 can be snapped into the limiting grooves 19. The limiting grooves 19 can provide a limiting effect on the variable stiffness module 21.

[0037] Furthermore, the limiting portion 24 includes a first folding block 241, a second folding block 242, and a hinged end 243. The first folding block 241 and the second folding block 242 are hinged to the hinged end 243. The first folding block 241 and the second folding block 242 can move closer to or farther away from each other around the hinged end 243. The first folding block 241 and the second folding block 242 can be hinged using a hinge column or a soft material connection. The end of the first folding block 241 away from the hinged end 243 is hinged to the outer wall of the variable stiffness module 21, and the end of the second folding block 242 away from the hinged end 243 is hinged to the outer wall of the variable stiffness module 21. The hinged end 243 can be snapped into the limiting groove 19. In this embodiment, before the variable stiffness module 21 moves into position, the variable stiffness module 21 maintains a low stiffness state with a relatively low "density". At this time, the outer wall of the variable stiffness module 21 is in an expanded state, and the two ends of the first folding block 241 and the second folding block 242 are far apart. Therefore, the hinge end 243 is pulled apart by the first folding block 241 and the second folding block 242, so that it can be away from the limiting groove 19. The limiting groove 19 does not form a limiting effect on the hinge end 243, so that the variable stiffness module 21 can move freely. When the variable stiffness module 21 moves into place, the variable stiffness module 21 becomes a high stiffness state with a larger "density", and the outer wall of the variable stiffness module 21 is in a taut and contracted state. In the contracted state, the two ends of the first folding block 241 and the second folding block 242 are close to each other, so that the hinge end 243 protrudes from the outside of the variable stiffness module 21. The protruding hinge end 243 can contact the edge of the limiting groove 19, so that the edge of the limiting groove 19 forms a limiting effect on the variable stiffness module 21.

[0038] Therefore, in the second embodiment, the first folding block 241, the second folding block 242 and the hinged end 243 are provided so that the distance between the hinged end 243 and the limiting groove 19 can be affected by whether the stiffness changing module 21 changes stiffness, thereby allowing the stiffness changing module 21 to move freely before changing stiffness, and after changing stiffness, it will be affected by the limiting effect to achieve a better positioning effect.

[0039] In order to enable the mobile variable stiffness device to achieve not only stiffness changes between the two ends but also stiffness changes in the areas on both sides, the present invention also discloses a third embodiment, see Figure 7In the third embodiment, the variable stiffness module 21 is divided into a left movable block 213 and a right movable block 214. The left movable block 213 and the right movable block 214 are isolated from each other by a partition 215. The left movable block 213 and the right movable block 214 are both filled with particles 23. The inner cavities of the left movable block 213 and the right movable block 214 can change their "density" respectively, that is, the gaps between the particles 23 in the left movable block 213 and the right movable block 214 can be changed respectively, so that the stiffness of the left movable block 213 and the right movable block 214 changes differently, achieving multi-region stiffness changes. Furthermore, the variable stiffness gas supply pipe 33 is divided into a first branch pipe 331 and a second branch pipe 332. The first branch pipe 331 passes through the first connecting surface 12 to communicate with the left movable block 213, and the second branch pipe 332 passes through the second connecting surface 13 to communicate with the right movable block 214. The lengths of the first branch pipe 331 and the second branch pipe 332 are both greater than the lengths of the first air cavity 14 and the second air cavity 15. Therefore, in order to accommodate the first branch pipe 331 and the second branch pipe 332, the top surface 211 and the bottom surface 212 are both curved surfaces with a concave center portion to respectively accommodate the coiled first branch pipe 331 and the second branch pipe 332.

[0040] The present invention also discloses a fourth embodiment, see Figure 8 and Figure 9 In the fourth embodiment, to ensure that the variable stiffness module 21 can move smoothly within the movable cavity 111, the housing assembly 1 further includes a guide tube 16. The guide tube 16 is disposed within the movable cavity 111 and connected between the first connecting surface 12 and the second connecting surface 13. The variable stiffness module 21 is provided with a through hole 216 that passes through the top surface 211 and the bottom surface 212. The guide tube 16 can pass through the through hole 216. Guided by the guide tube 16, the variable stiffness module 21 can move smoothly along the movable cavity 111 between the first air cavity 14 and the second air cavity 15.

[0041] Furthermore, in order to achieve a better positioning effect, the guide tube 16 is hollow inside, and the two ends of the guide tube 16 are respectively connected to the first gas pipe 31 and the second gas pipe 32. A diaphragm 161 is provided in the middle of the guide tube 16, and the diaphragm 161 divides the guide tube 16 into a first half tube 17 and a second half tube 18. The first half tube 17 is provided with a first through hole 171, and the first through hole 171 is only connected to the first air cavity 14. The second half tube 18 is provided with a second through hole 181, and the second through hole 181 is only connected to the second air cavity 15. During use, the first gas pipe 31 supplies gas to the first gas cavity 14, and gas can enter the first gas cavity 14 from the first through hole 171. However, due to the blocking effect of the diaphragm 161, the gas coming out of the first gas pipe 31 cannot directly enter the second gas cavity 15. The second gas pipe 32 supplies gas to the second gas cavity 15, and gas can enter the second gas cavity 15 from the second through hole 181. However, due to the blocking effect of the diaphragm 161, the gas coming out of the second gas pipe 32 cannot directly enter the first gas cavity 14. When the air pressure in the first air cavity 14 is greater than the air pressure in the second air cavity 15, the variable stiffness module 21 moves from the first air cavity 14 to the second air cavity 15, and the radius of the second half pipe 18 increases under the action of the air pressure. When the variable stiffness air supply pipe 33 inputs negative pressure to the variable stiffness module 21, the outer wall of the variable stiffness module 21 will shrink and squeeze, and the through hole 216 will shrink to produce wrinkles and generate contact friction with the enlarged second half pipe 18, thereby forming a limiting effect on the variable stiffness module 21 after the stiffness is changed.

[0042] Furthermore, in order to avoid cross-flow, the first through hole 171 is arranged at one end of the first half pipe 17 close to the first connecting surface 12. When the variable stiffness module 21 is located at the extreme position of the first air cavity 14, the first through hole 171 is located between the concave curved surface of the top surface 211 and the first connecting surface 12. Therefore, the concave curved surface of the top surface 211 can form an avoidance for the first through hole 171, so that the gas in the first through hole 171 can pass into the first air cavity 14. However, due to the obstruction of the top surface 211, the gas cannot enter the second through hole 181, thereby avoiding cross-flow. Similarly, the second through hole 181 is provided at one end of the second half pipe 18 close to the second connecting surface 13. When the variable stiffness module 21 is located at the extreme position of the second air cavity 15, the second through hole 181 is located between the concave curved surface of the bottom surface 212 and the second connecting surface 13. The concave curved surface of the bottom surface 212 can form an avoidance for the second through hole 181, so that the gas in the second through hole 181 can pass into the second air cavity 15. However, due to the obstruction of the bottom surface 212, the gas cannot enter the first through hole 171, and cross-gas is avoided.

[0043] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A mobile variable stiffness device, characterized in that: The invention comprises a housing assembly, a variable stiffness assembly and a drive assembly, wherein the housing assembly comprises an outer shell, a first connection surface and a second connection surface, wherein the first connection surface and the second connection surface are respectively provided at two ends of the outer shell, the outer shell is sealed, a movable cavity is sealed in the outer shell, and the variable stiffness assembly is provided in the movable cavity; The variable stiffness assembly includes a variable stiffness module, the variable stiffness module is sealed, a sealed cavity is provided inside the variable stiffness module, the sealed cavity is filled with particles, the variable stiffness module is provided in the movable cavity, and a top surface and a bottom surface are provided at both ends of the variable stiffness module, the top surface, the shell and the first connecting surface can enclose a first air cavity, and the bottom surface, the shell and the second connecting surface can enclose a second air cavity, and the variable stiffness module can reciprocate between the first air cavity and the second air cavity; The drive assembly includes a first air delivery pipe, a second air delivery pipe, and a variable stiffness air delivery pipe connected to an external air pump, the first air delivery pipe is connected to the first air cavity, the second air delivery pipe is connected to the second air cavity, and the variable stiffness air delivery pipe is connected to the sealed cavity; The variable stiffness assembly further includes a plurality of limiting portions, the limiting portions surrounding the outer wall of the variable stiffness module, and a plurality of limiting grooves are provided on the inner wall of the housing, and the side portions of the limiting portions can be snapped into the limiting grooves; The limiting portion includes a first folding block, a second folding block and a hinged end, the first folding block and the second folding block are hinged on the hinged end, the end of the first folding block away from the hinged end is hinged on the outer wall of the variable stiffness module, and the end of the second folding block away from the hinged end is hinged on the outer wall of the variable stiffness module, and the hinged end can be stuck in the limiting groove.

2. The mobile variable stiffness device according to claim 1, characterized in that: The first air pipe is connected to the first air cavity through the first connecting surface, the second air pipe is connected to the second air cavity through the second connecting surface, and the variable stiffness air pipe is connected to the sealing cavity through the first connecting surface or the second connecting surface.

3. The mobile variable stiffness device according to claim 1, characterized in that: The variable stiffness gas pipe is flexibly arranged, and the variable stiffness gas pipe is connected to the top surface, and the top surface is a curved surface with a concave middle portion, or the variable stiffness gas pipe is connected to the bottom surface, and the bottom surface is a curved surface with a concave middle portion.

4. The mobile variable stiffness device according to claim 1, characterized in that: The variable stiffness module is divided into a left moving block and a right moving block. The left moving block and the right moving block are isolated from each other by a partition. Both the left moving block and the right moving block are filled with granular elements.

5. The mobile variable stiffness device according to claim 4, characterized in that: The variable stiffness gas transmission pipe is divided into a first branch pipe and a second branch pipe, the first branch pipe passes through the first connecting surface and is connected to the left movable block, and the second branch pipe passes through the second connecting surface and is connected to the right movable block; The top surface and the bottom surface are both curved surfaces with a concave center.

6. The mobile variable stiffness device according to claim 1, characterized in that: The shell assembly also includes a guide tube, which is arranged in the movable cavity and connected between the first connecting surface and the second connecting surface. A through hole is provided in the variable stiffness module, and the through hole passes through the top surface and the bottom surface. The guide tube can pass through the through hole.

7. The mobile variable stiffness device according to claim 6, characterized in that: The guide tube is hollow inside, and the two ends of the guide tube are respectively connected to the first gas pipe and the second gas pipe. A diaphragm is provided in the middle of the guide tube, and the diaphragm divides the guide tube into a first half tube and a second half tube. The first half tube is provided with a first through hole, and the first through hole is only connected to the first air cavity. The second half tube is provided with a second through hole, and the second through hole is only connected to the second air cavity.

8. The mobile variable stiffness device according to claim 7, characterized in that: The first through hole is provided at one end of the first half tube close to the first connecting surface. When the variable stiffness module is located at the extreme position of the first air cavity, the first through hole is located between the concave curved surface of the top surface and the first connecting surface. The second through hole is provided at one end of the second half tube close to the second connecting surface. When the variable stiffness module is located at the extreme position of the second air cavity, the second through hole is located between the concave curved surface of the bottom surface and the second connecting surface.

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