Membrane bag composite

Abstract

To provide a membrane bag composite capable of gripping various workpieces.SOLUTION: A membrane bag composite includes: a flexible bag body which has an opening and in which a curable medium composed of fluid or powder is filled; a base member which is disposed so as to block the opening of the bag body and has a communication hole communicating the inside and the outside of the bag body; and a curing part inserted into the communication hole so as to be movable in the center axis direction of the communication hole. The curing part cures the curable medium to hold the bag body in an arbitrary shape.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a film bag composite.

Background Art

[0002] The environment surrounding Japanese factories is in a very severe situation due to the labor shortage caused by the declining population. Therefore, although the automation of manufacturing processes is being promoted, assembling diversified parts with a common tool in recent multi-variety and small-batch production is a challenging task. In an assembly tool, a device for gripping or operating a part is, for example, an end effector. In order to grip various workpieces with the same end effector, a method of mounting a mechanism capable of changing rigidity on the end effector has been proposed.

[0003] As an example of a rigidity variable mechanism, a bag gripper device, which is a type of soft gripper mechanism, can be exemplified. The bag gripper device has a configuration in which a content capable of switching rigidity is enclosed in the internal space of the bag body. The bag gripper device presses the bag body against the workpiece while the bag body is in a soft state to conform to the shape of the workpiece, and switches the inside of the bag body to a hard state to hold the shape of the bag body, thereby gripping the workpiece. As a method for realizing the switching of the rigidity of the bag body, a method has been proposed in which a magnetorheological fluid or an electrorheological fluid is enclosed in the bag body, and a magnetic field or an electric field is applied to increase the viscosity of the fluid in the bag body (see, for example, Patent Documents 1 and 2).

[0004] The bag gripper device described in Patent Document 1 is a bag gripper device using a magnetorheological fluid. In this bag clipper device, by using a mechanism capable of varying the distance between a permanent magnet and the bag body as a means for increasing and decreasing the magnetic field, a higher magnetic field is generated with a smaller mechanism than when using an electromagnet as a means for increasing and decreasing the magnetic field.

[0005] The bag gripper device described in Patent Document 2 has a configuration in which a magnetorheological fluid or electroviscous fluid is sealed inside the bag, and the viscosity of the fluid inside the bag can be controlled using an electromagnet or high-voltage electrode. In this bag clipper device, a pressure sensor is provided inside the bag, and the internal pressure of the bag is adjusted by a fluid supply and discharge mechanism, thereby changing the mechanical compliance of the bag and improving the gripping ability. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6385014 [Patent Document 2] Japanese Patent Publication No. 2004-154909 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the hardening of magnetic or dielectric fluids or powders only occurs within the range of the magnetic or electric field. Therefore, in configurations such as those described in Patent Documents 1 and 2, as the size of the gripper (bag) increases, the hardening of the fluid or powder at the gripper tip may become insufficient, or the fluid or powder may not harden at all.

[0008] The purpose of this disclosure is to provide a membrane bag composite capable of gripping a variety of workpieces. [Means for solving the problem]

[0009] The membrane bag composite of the present disclosure comprises a flexible bag having an opening, the bag being filled with a curable medium composed of a fluid or powder, a base member disposed to close the opening of the bag and having a communication hole that connects the inside and outside of the bag, and a curing portion inserted into the communication hole so as to be movable in the central axis direction of the communication hole, wherein the curing portion holds the bag in any shape by curing the curable medium. [Effects of the Invention]

[0010] The membrane bag composite of this disclosure can grip a variety of workpieces. [Brief explanation of the drawing]

[0011] [Figure 1] Side view schematic of the bag gripper in the first embodiment [Figure 2] A schematic side view showing the bag gripper in the first embodiment gripping a workpiece. [Figure 3] Schematic diagram of a longitudinal section of the bag gripper in the first embodiment. [Figure 4] A schematic cross-sectional view showing the bag gripper in the first embodiment gripping a workpiece. [Figure 5] Schematic cross-sectional view of the bag gripper in the first embodiment along line AA in Figure 4. [Figure 6] Side view schematic of the gripping system in the first embodiment [Figure 7] Side schematic diagram of another example of the gripping system in the first embodiment [Figure 8] Side view schematic of the jig system in the first embodiment [Figure 9] Side view schematic of the legged robot system in the first embodiment [Figure 10] Schematic diagram of the longitudinal section of the bag gripper in the second embodiment. [Figure 11] Schematic diagram of the longitudinal section of the bag gripper in the third embodiment. [Figure 12] Schematic cross-sectional view of the bag gripper in the third embodiment along line BB in Figure 11 [Figure 13] Schematic diagram of the longitudinal section of the bag gripper in the fourth embodiment. [Figure 14] Schematic diagram of the longitudinal section of the bag gripper in the fifth embodiment. [Figure 15] Schematic diagram of the longitudinal section of the bag gripper in the sixth embodiment. [Modes for carrying out the invention]

[0012] [Embodiment] Embodiments of the present disclosure will be described.

[0013] <First Embodiment> Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. In the first embodiment, as an example of the film bag composite in the present disclosure, a bag gripper will be exemplified and described. However, the film bag composite of the present disclosure is not limited to the bag gripper, and can be widely used for gripping devices, jigs, robot arms, etc.

[0014] FIG. 1 is a schematic side view of the bag gripper 1 in the first embodiment. As shown in FIG. 1, the bag gripper 1 includes a bag body 2 and a housing 3.

[0015] The bag body 2 is formed in a semi-elliptical spherical shape having one opening with a flexible material, for example, silicone rubber. Note that the shape of the bag body 2 is not limited to the semi-elliptical spherical shape, and may be, for example, a hemispherical shape or a cylindrical shape. The bag body 2 can flexibly conform to the workpiece. The inside of the bag body 2 is filled with a magnetorheological fluid. The magnetorheological fluid is an example of the curable medium of the present disclosure.

[0016] The bag gripper 1 is connected to the control device 4 via a connection member 5. The connection member 5 is composed of an electric wire.

[0017] After the bag body 2 is pressed against the workpiece and closely adheres to wrap around the workpiece, the control device 4 applies a first electrical signal to the bag gripper 1 via the connection member 5. By applying this first electrical signal, the viscosity of the magnetorheological fluid increases, and the bag body 2 hardens in the state of wrapping around the workpiece. As a result, the bag gripper 1 can grip the workpiece. In the first embodiment, the control device 4 is installed outside the bag gripper 1. However, when the control device 4 is installed inside the bag gripper 1, the connection member 5 may not be installed.

[0018] Figure 2 is a schematic side view showing the bag gripper 1 in the first embodiment gripping a workpiece.

[0019] The bag gripper 1 grips the workpiece 6 when a first electrical signal is applied by the control device 4, and releases the grip from the workpiece 6 when a second electrical signal is applied. The shape of the workpiece 6 to be gripped by the bag gripper 1 is not particularly limited. Furthermore, it is desirable that the workpiece 6 does not damage the bag 2. A workpiece 6 that damages the bag 2 is, for example, an object coated with a chemical that dissolves the bag 2, or an object that can puncture or abrade the bag 2, thereby creating a hole in the bag 2 and causing it to lose its airtightness.

[0020] Figure 3 is a schematic longitudinal cross-sectional view of the bag gripper 1 in the first embodiment. The bag gripper 1 further comprises a base member 7, a magnetorheological fluid 8, a cylindrical member 9, a sealing member 10, a magnet 11, a magnet fixing member 12, a linear actuator 13, an elastic element 14 on the cylindrical member side, an elastic element 15 on the magnet side, and a guide mechanism 16.

[0021] A linear actuator 13 is fixed to the other end (upper end in Figure 3) of the housing 3. The linear actuator 13 comprises a main body 13A fixed to the housing 3 and a movable element 13B that moves relative to the main body 13A. The linear actuator 13 is configured such that when a first electrical signal is applied by the control device 4, the movable element 13B moves away from the main body 13A, and when a second electrical signal is applied, the movable element 13B moves towards the main body 13A.

[0022] A base member 7 is fixed to one end of the housing 3 (the lower end in Figure 3). A guide mechanism 16 is fixed to the other end of the housing 3, beyond the base member 7.

[0023] The bag body 2 is fixed to the base member 7, for example, by adhesive. The opening of the bag body 2 is sealed by the base member 7 so that it is watertight. The inside of the bag body 2 is filled with magnetorheological fluid 8. The base member 7 has the same number of communication holes as the number of cylindrical members 9 (12). Each communication hole in the base member 7 is formed to connect the inside and outside of the bag body 2. A cylindrical member 9 is inserted through each communication hole in the base member 7. The space between the communication holes of the base member 7 and the cylindrical members 9 is sealed by a sealing member 10 so that the communication holes are watertight. Due to the elasticity of the sealing member 10, a slight tilt of the cylindrical members 9 is allowed while maintaining watertightness. In this way, the base member 7 is configured so that the cylindrical members 9 can move within the communication holes while the watertightness of the bag body 2 is maintained.

[0024] The cylindrical member 9 has a cylindrical structure with a closed end on the bag body 2 side (hereinafter sometimes referred to as the "tip"). The cylindrical member 9 is guided by a guide mechanism 16 so that it can move in a direction along the central axis of the communication hole in the base member 7. A projection is formed on the end of the cylindrical member 9 on the linear actuator 13 side (hereinafter sometimes referred to as the "base end"). This projection prevents the cylindrical member 9 from falling out of the base member 7 towards the bag body 2. The cylindrical member 9 is fixed to the guide mechanism 16 via a cylindrical member-side elastic element 14. The cylindrical member 9 is subjected to an elastic force toward the bag body 2 by the cylindrical member-side elastic element 14. The guide mechanism 16 has the function of preventing the cylindrical member 9 from falling out toward the linear actuator 13.

[0025] The hardening portion of the first embodiment includes a cylindrical member 9 and a magnet 11. The magnet 11 is formed in a rod shape. The magnet 11 moves toward the bag body 2 side through the holes in the guide mechanism 16 and the communication holes in the base member 7 together with the cylindrical member 9, thereby applying magnetic force to the magnetorheological fluid 8 and hardening the magnetorheological fluid 8.

[0026] The end of the magnet 11 opposite to the bag body 2 is fixed to the magnet fixing member 12, for example, by adhesive. The magnet fixing member 12 is fixed to the movable element 13B of the linear actuator 13 via the magnet-side elastic element 15. The magnet 11 is movable in a direction along the central axis of the hole in the guide mechanism 16. The cylindrical member-side elastic element 14 and the guide mechanism 16 function as guides for the linear motion of the magnet 11. The material of the magnet fixing member 12 is, for example, a hard resin. The magnet 11 has a diameter smaller than the inner diameter of the cylindrical member 9 and is configured to be insertable into the inside of the cylindrical member 9.

[0027] The elastic element 14 on the cylindrical member side is composed of a spring. It is desirable that the initial load and spring constant of the elastic element 14 on the cylindrical member side be set so that the cylindrical member 9 does not move toward the linear actuator 13 due to its own weight, regardless of the orientation of the bag gripper 1 relative to the direction of gravity.

[0028] The magnet-side elastic element 15 is composed of a spring. The spring constant of the magnet-side elastic element 15 is desirable to be set so that the magnet 11 does not move significantly under its own weight, regardless of the orientation of the bag gripper 1 relative to gravity. A larger spring constant of the magnet-side elastic element 15 results in a faster return speed of the magnet 11. However, a large spring constant of the magnet-side elastic element 15 increases the reaction force from the workpiece 6 required for the deformation of the bag body 2, which is disadvantageous for gripping flexible or fragile workpieces.

[0029] In order to allow the bag body 2 to harden all the way to the tip, it is desirable that the tip of the magnet 11 reaches the tip of the cylindrical member 9 when the linear actuator 13 is fully extended (when the movable element 13B is furthest away from the main body 13A) without gripping a workpiece. When the linear actuator 13 is fully retracted (when the movable element 13B is closest to the main body 13A) without gripping a workpiece, it is desirable to design the bag gripper 1 such that the entire magnet 11 is completely removed from the cylindrical member 9, so that the magnetic force of the magnet 11 does not act on the magnetorheological fluid 8 as much as possible.

[0030] The shape of the cylindrical member 9 is not limited to a cylindrical shape; for example, it may be a hexagonal tube. The smaller the distance between adjacent cylindrical members 9, the higher the viscosity of the magnetorheological fluid 8 can be made. The shape of the tip of the cylindrical member 9 is not limited to a straight cylinder; a cylindrical shape in which the inner diameter increases as it approaches the base end allows the magnet 11 to enter more easily, but the amount of inclination that can be allowed in the cylindrical member 9 may be more restricted.

[0031] The material of the cylindrical member 9 should preferably be a material with low coercivity and high permeability. A material with low coercivity and high permeability is, for example, soft iron. However, if the magnetic force of the magnet 11 is large and the frictional force caused by the magnet 11 attracting the cylindrical member 9 prevents the magnet 11 from moving even when the linear actuator 13 is extended, then the material of the cylindrical member 9 should preferably be a non-magnetic material. For example, the cylindrical member 9 should preferably be made of a resin material. In this case, the thickness of the cylindrical member 9 should be thin in order to allow magnetic field lines to pass through easily.

[0032] The number of cylindrical members 9 is not limited to 12; any number is acceptable as long as the magnetic field lines are arranged to sufficiently penetrate the magnetoviscous fluid 8.

[0033] Although the cylindrical member 9 is constructed from a single cylindrical member, it may also be a telescopic structure. The telescopic structure in this disclosure is a structure that has elasticity such that it reaches its maximum length in an unloaded state and, when an external force is applied to compress it, an elastic force acts in the direction of expansion. By making the cylindrical member 9 a telescopic structure, the axial length (the direction in which the linear actuator 13 extends) of the bag gripper 1 of the guide mechanism 16 can be shortened. As a result, the axial length of the bag gripper 1 can be shortened. However, if the diameter of the part of the cylindrical member 9 that contacts the sealing member 10 changes as the telescopic structure of the cylindrical member 9 expands and contracts, it is required that the watertightness or airtightness inside the bag body 2 by the sealing member 10 is not lost regardless of the expansion and contraction of the telescopic structure.

[0034] The linear actuator 13 is not limited to one unit, but may be provided in multiple units. For example, the same number of linear actuators 13 may be provided as the number of magnets 11, and each linear actuator 13 may move each magnet 11 independently.

[0035] In the example shown in Figure 3, an electric cylinder is exemplified as the linear actuator 13, but a pneumatic cylinder may also be used. If a pneumatic cylinder is used, for example, the following configuration may be applied. That is, a pneumatic control device is used as the control device 4, and an air tube is used as the connecting member 5. A piston rod is used as the magnet fixing member 12, and a cylinder tube is used as the guide mechanism 16. A pneumatic cylinder structure is arranged in which a piston packing is provided on the piston rod to airtightly seal the space between it and the cylinder tube. Furthermore, a pneumatic linear actuator is arranged to move the piston rod of the pneumatic cylinder structure in a linear motion. In this case, each pneumatic linear actuator does not need to be driven independently, but air pressure may be applied simultaneously to the extension or contraction side, and the magnet-side elastic element 15 can be omitted because the pneumatic cylinder functions as an air spring.

[0036] In the example shown in Figure 3, the movable element 13B of the linear actuator 13 is directly fixed to one end of the magnet-side elastic element 15, but the invention is not limited to this, and the movable element 13B of the linear actuator 13 may be connected to one end of the magnet-side elastic element 15 via a power transmission mechanism such as a wire mechanism, a link mechanism, or a fluid pressure tube. For example, by placing the linear actuator 13 outside the housing 3 and transmitting the power of the linear actuator 13 to the magnet-side elastic element 15 via the power transmission mechanism, the axial size of the bag gripper 1 can be reduced. If the power transmission mechanism is elastic and can achieve the same function as the magnet-side elastic element 15, one end of the power transmission mechanism may be directly fixed to one end of the magnet fixing member 12 without providing the magnet-side elastic element 15. The linear actuator 13 is not limited to a linear actuator as long as it is a mechanism that moves the magnet-side elastic element 15 in a linear motion via the power transmission mechanism, and may be a rotary actuator, for example.

[0037] Figure 4 is a schematic longitudinal cross-sectional view showing the state in which the bag gripper 1 grips the workpiece 6 in the first embodiment. When the workpiece 6 is pushed into the bag body 2, the bag body 2 deforms, and the cylindrical member 9 is pushed up toward the linear actuator 13. Subsequently, the linear actuator 13 is extended by the application of the first electrical signal by the control device 4, and when the magnet 11 moves to the tip inside the cylindrical member 9, magnetic field lines pass through the magnetorheological fluid 8. When magnetic field lines pass through the magnetorheological fluid 8, the viscosity of the magnetorheological fluid 8 increases, and the workpiece 6 is gripped by the bag gripper 1.

[0038] The magnets 11 attract each other through magnetic field lines. Since the sealing member 10, positioned between the base member 7 and the cylindrical member 9, is elastic, a force acts on the cylindrical member 9 in the direction toward the central axis of the bag 2 due to the attractive force between the magnets 11. This force acting toward the central axis of the bag 2 has the effect of preferentially hardening the magnetoviscous fluid 8 near the workpiece 6 gripped near the central axis of the bag 2, and also acts as a gripping force on the workpiece 6. Furthermore, on the linear actuator 13 side of the base member 7, a guide mechanism 16 exists between each magnet 11, so the magnets 11 attract each other through magnetic field lines, and even if the linear actuator 13 is extended due to frictional force generated by the magnetic force, the magnets 11 will not become immobile.

[0039] Although the sealing member 10 is highly elastic and allows for a slight tilt relative to the cylindrical member 9, the bag gripper 1 will still have gripping performance even if the sealing member 10 is configured not to allow tilting relative to the cylindrical member 9.

[0040] On the other hand, when the linear actuator 13 is retracted by the application of a second electrical signal by the control device 4, the magnet 11 detaches from the cylindrical member 9, and magnetic field lines can no longer pass through the magnetorheological fluid 8. When magnetic field lines can no longer pass through the magnetorheological fluid 8, the viscosity of the magnetorheological fluid 8 decreases, and the gripper 1 releases the workpiece 6. As the grip on the workpiece 6 is released, the cylindrical member 9 is pushed back towards the bag body 2 by the elastic element 14 on the cylindrical member side.

[0041] Figure 5 is a schematic cross-sectional view of the bag gripper 1 in the first embodiment along line AA in Figure 4. In Figure 5, 11a is the north pole of the magnet 11, 11b is the south pole of the magnet 11, and 17 are magnetic field lines. The viscosity of the magnetorheological fluid 8 increases as the magnetic field lines 17 penetrate the magnetorheological fluid 8.

[0042] In the example shown in Figure 5, the magnet 11 has, in its entire region along the central axis, one side of a plane containing the central axis and parallel to the central axis is a north pole 11a, and the other side is a south pole 11b. Multiple such magnets 11 are arranged on concentric circles around the central axis of the bag 2, with the north poles 11a and south poles 11b alternating. Alternatively, multiple magnets 11, each with a north pole 11a at one end along the central axis and a south pole 11b at the other end, may be arranged on concentric circles around the central axis of the bag 2, with the north poles 11a and south poles 11b alternating on the concentric circles.

[0043] Next, a gripping system according to the first embodiment will be described. Figure 6 is a schematic side view of the gripping system. In the gripping system, the bag gripper 1 is attached to the end-effector 19 of the robot arm 18. The robot arm 18 can move three-dimensionally within a predetermined range of motion and can assume any posture.

[0044] In the example in Figure 6, the robot arm 18 is fixed to the upper surface of the robot support base 20, but it may also be fixed directly to the floor. In the example in Figure 6, the robot arm 18 is a vertical articulated robot, but it is not limited to this, and may also be a horizontal articulated robot or a parallel link robot, for example. In the example in Figure 6, the workpiece 6 is placed directly on the floor, but it is not limited to this, and may be placed in a container, for example.

[0045] The bag gripper 1 can stably grip the workpiece 6 even if the orientation of the workpiece 6 is not constant, because the bag body 2 conforms to the shape of the workpiece 6. When workpieces 6 are close together, it is desirable to control the robot arm 18 so that the bag gripper 1 does not simultaneously grip another workpiece 6 adjacent to the workpiece 6 to be gripped.

[0046] The connecting member 5 is, for example, a shielded multi-core electric wire. It is desirable that the connecting member 5 has enough flexibility so as not to hinder the movement of the robot arm 18.

[0047] The control device 4 is connected to the bag gripper 1 by a connecting member 5. After the robot arm 18 presses the bag gripper 1 against the workpiece 6, the control device 4 applies a first electrical signal to the bag gripper 1 to increase the viscosity of the magnetorheological fluid 8 inside the bag 2, thereby hardening the bag 2. This hardening of the bag 2 causes the bag gripper 1 to grip the workpiece 6. The control device 4 then applies a second electrical signal to the bag gripper 1 to decrease (return to normal) the viscosity of the magnetorheological fluid 8 inside the bag 2, thereby softening the bag 2. This softening of the bag 2 causes the bag gripper 1 to release its grip on the workpiece 6.

[0048] In the example shown in Figure 6, the control device 4 is installed on the floor, but it may be installed in other locations as long as it does not impair the functions of the bag gripper 1 described above. For example, the control device 4 may be fixed to the robot arm 18.

[0049] Figure 7 is a schematic side view of another example of the gripping system in the first embodiment. In this example of the gripping system, the aforementioned bag grippers 1 are positioned on the claw portions 22 of the two-finger gripper 21.

[0050] The two-finger gripper 21 grips the workpiece 6 with the bag grippers 1 each provided on the claw portion 22. Subsequently, the control device 4 applies a first electrical signal to the bag grippers 1 to harden the bag body 2. This hardening of the bag body 2 causes the two bag grippers 1 to grip the workpiece 6. After the control device 4 applies a second electrical signal to the bag grippers 1 to soften the bag body 2, the two-finger gripper 21 opens the claw portion 22. This softening of the bag body 2 and the opening of the claw portion 22 release the two bag grippers 1 from gripping the workpiece 6. As shown in the example in Figure 7, not only is the gripping force of the two-finger gripper 21 and the gripping force of the bag grippers 1 simply matched, but the bag body 2 is also configured to conform to the shape of the workpiece 6. Therefore, compared to the case where the bag grippers 1 are not positioned on the claw portion 22 and the claw portion 22 directly grips the workpiece 6, a more stable grip of the workpiece 6 is possible.

[0051] In the example in Figure 7, when releasing the grip, the bag body 2 is softened before opening the claw portion 22, but this is not limited to this. If the gripping force of the bag gripper 1 alone is insufficient to grip the workpiece 6, the claw portion 22 may be opened first, and then the bag body 2 may be softened. In the example in Figure 7, the bag gripper 1 is attached to a two-finger gripper 21, but this is not limited to this. The bag gripper 1 may also be attached to a multi-fingered hand with three or more fingers. Furthermore, by placing the bag gripper 1 not only in positions corresponding to the fingertips of the gripper, but also in positions corresponding to the palm, for example, the overall shape of the gripper can be made to conform to the workpiece 6.

[0052] Next, a jig system according to the first embodiment will be described. Figure 8 is a schematic side view of the jig system. In the jig system, the bag gripper 1 is attached to the vertically movable and rotatable end portion 19 of the robot arm 18. In the example in Figure 8, the workpiece 6 is a screw part having a slot in its head and is attached to the female screw hole of the work-in-progress 23.

[0053] The control device 4 is connected to the bag gripper 1 by a connecting member 5. After the bag gripper 1 is pressed against the workpiece 6 by the drive of the robot arm 18, the control device 4 applies a first electrical signal to the bag gripper 1 to harden the bag body 2 by increasing the viscosity of the magnetorheological fluid 8 inside the bag body 2. As a result, the bag gripper 1 hardens to conform to the head shape of the workpiece 6 and grips the workpiece 6, acting as a flathead screwdriver. Subsequently, by rotating the end portion 19 upward or downward in accordance with the screw pitch of the workpiece 6, the workpiece 6 can be inserted into or removed from the work-in-progress 23. The control device 4 also applies a second electrical signal to the bag gripper 1 to soften the bag body 2 by returning the viscosity of the magnetorheological fluid 8 inside the bag body 2 to its original level. This softening of the bag body 2 allows the bag gripper 1 to release its grip on the workpiece 6.

[0054] Next, a legged robot system according to the first embodiment will be described. Figure 9 is a schematic side view of the legged robot system. In the legged robot system, bag grippers 1 are positioned at the end of each leg of the legged robot 24 and transmit leg force to the ground 25. A control device 4 is attached to the body of the legged robot 24 and controls each bag gripper 1 via a connecting member 5. As the legged robot system walks, after the bag gripper 1 is pressed against the ground 25, the control device 4 applies a first electrical signal to the bag gripper 1 to harden the bag body 2. This hardening of the bag body 2 allows the bag gripper 1 to grip the ground 25. As the legged robot system walks, after the bag gripper 1 is lifted off the ground 25, the control device 4 applies a second electrical signal to the bag gripper 1 to soften the bag body 2. As shown in the example in Figure 9, the bag body 2 of the bag gripper 1 hardens to conform to the shape of the ground 25 and grips the ground 25, enabling more stable movement compared to when the bag gripper 1 is not attached to the tip of the leg robot 24 and the leg robot 24 is in direct contact with the ground 25.

[0055] In the example shown in Figure 9, the legged robot 24 has four legs, but it is not limited to this, and bag grippers 1 may be attached to the end of each leg of a two-legged or six-legged legged robot.

[0056] <Second Embodiment> Next, a second embodiment of the present disclosure will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. Figure 10 is a schematic longitudinal cross-sectional view of the bag gripper 26 in the second embodiment.

[0057] As shown in Figure 10, the bag gripper 26 in the second embodiment, like the first embodiment, comprises a bag body 2 and maintains the shape of the bag body 2 by magnetic force. Unlike the first embodiment, the filling material inside the bag body 2 in the second embodiment is magnetic powder 27. The magnetic powder 27 is an example of a curable medium of this disclosure.

[0058] It is desirable that the magnetic powder 27 has high fluidity such that, after the bag 2 softens, the cylindrical member 9 can move to the front end of the bag 2 as far as possible by pushing away the magnetic powder 27 with the elastic force of the elastic element 14 on the cylindrical member side. Such a fluid magnetic powder 27 is, for example, spherical powder. It is desirable that the magnetic powder 27 be a material with low coercivity and high permeability, for example, soft iron spheres with a diameter of 1 mm.

[0059] In the example of Figure 10, the tip of the cylindrical member 9 has a constant diameter, but it is not limited to this; for example, it may have a tapered shape that becomes narrower towards the tip. In this case, the cylindrical member 9 can more easily push away the magnetic powder 27. However, if the cylindrical member 9 is tapered and the magnet 11 is also tapered, the magnetic force at the tip of the cylindrical member 9 decreases when the magnet 11 is inserted to the tip of the cylindrical member 9, and the force that maintains the shape of the bag 2 decreases.

[0060] In the example in Figure 10, the filling medium other than the magnetic powder 27 in the bag 2 is air, but it is not limited to this. Any fluid that does not damage the bag 2, base member 7, cylindrical member 9, sealing member 10, or magnetic powder 27 may be used, such as nitrogen gas or silicone oil. Furthermore, by using a fluid with rust-preventive properties, such as rust-preventive oil, as the filling medium other than the magnetic powder 27, oxidation of the cylindrical member 9 or magnetic powder 27 can be suppressed. When using the same fluid as the ambient environment in which the bag gripper 26 operates as the filling medium other than the magnetic powder 27, unlike in the first embodiment, watertightness or airtightness is not required for the sealing between the bag 2 and the base member 7, and for the sealing between the base member 7 and the cylindrical member 9 by the sealing member 10. It is sufficient to ensure that the magnetic powder 27 does not leak out. On the other hand, when a fluid different from the ambient environment in which the bag gripper 26 operates is used as a filling medium other than the magnetic powder 27, the sealing between the bag body 2 and the base member 7, and the sealing between the base member 7 and the cylindrical member 9 by the sealing member 10, must be airtight or watertight.

[0061] <Third Embodiment> Next, a third embodiment of this disclosure will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. Figure 11 is a schematic longitudinal cross-sectional view of the bag gripper 28 in the third embodiment.

[0062] In the third embodiment, the bag gripper 28, like in the first embodiment, has a fluid sealed inside the bag body 2 while maintaining watertightness. However, unlike the first embodiment, the sealed material inside the bag body 2 in the third embodiment is an electroviscous fluid 29. The electroviscous fluid 29 is an example of a curable medium of this disclosure. Furthermore, the configuration corresponding to the cylindrical member 9 and magnet 11 in the first embodiment is 16 high-pressure electrodes 31 in the third embodiment, and the configuration corresponding to the cylindrical member-side elastic element 14 in the first embodiment is a high-pressure electrode-side elastic element 32 in the third embodiment. The high-pressure electrodes 31 constitute the curing portion of the third embodiment. The high-pressure electrodes 31 are cylindrical in shape and made of iron. No insulating film is formed on the surface of the high-pressure electrodes 31. The high-pressure electrode-side elastic element 32 is made of a spring, similar to the cylindrical member-side elastic element 14.

[0063] The base end of the high-voltage electrode 31 (the end connected to the high-voltage electrode side elastic element 32) has a projection, similar to the cylindrical member 9 in the first embodiment, to prevent the high-voltage electrode 31 from falling out of the base member 7 towards the bag body 2. The spacing between the high-voltage electrodes 31 should be as narrow as possible while maintaining the insulation distance, as this allows for a higher electric field strength at a lower voltage. Similar to the first embodiment, the high-voltage electrode 31 is allowed to tilt slightly due to the elasticity of the sealing member 10. The base member 7 is configured so that the high-voltage electrode 31 can move within the communication hole of the base member 7 while the watertightness of the bag body 2 is maintained by the sealing member 10. Similar to the first embodiment, a force acts on the high-voltage electrode 31 in the direction toward the central axis of the bag body 2 due to the electrostatic force generated between the high-voltage electrodes 31. This force acting toward the central axis of the bag body 2 has the effect of preferentially hardening the electroviscous fluid 29 near the workpiece gripped near the central axis of the bag body 2, and also acts as a gripping force on the workpiece. However, in the third embodiment, it is required that even if the high-voltage electrodes 31 are tilted to their maximum angle, the distance between the high-voltage electrodes 31 can be maintained at a distance greater than or equal to the insulating distance.

[0064] The sealing member 10 allows for a slight inclination relative to the high-voltage electrode 31, but even if the sealing member 10 is configured not to allow inclination relative to the high-voltage electrode 31, the bag gripper 1 will still have gripping performance.

[0065] The housing 3, base member 7, sealing member 10, and guide mechanism 16 are required to have high insulation resistance and dielectric strength that prevents dielectric breakdown by the high voltage applied to the high-voltage electrodes 31. In the region of the bag 2 opposite the base member 7, the guide mechanism 16 acts as an insulating plate, insulating the adjacent high-voltage electrodes 31.

[0066] The connecting member 5 electrically connects the control device 4 and the high-voltage electrode 31. Similar to the first embodiment, the connecting member 5 is an electric wire, preferably one capable of withstanding high voltage. However, if the high-voltage generation circuit of the control device 4 is installed inside the bag gripper 28, the connecting member 5 does not need to be capable of withstanding high voltage. Furthermore, if the control device 4 is installed inside the bag gripper 28, the connecting member 5 does not need to be installed.

[0067] The control device 4 controls the bag gripper 28, similar to the first embodiment. However, unlike the first embodiment, the control device 4 in the third embodiment applies a high voltage to the high-voltage electrode 31 of the bag gripper 28 via the connecting member 5, thereby hardening the bag body 2 by increasing the viscosity of the electroviscous fluid 29 inside the bag body 2. As a result, the bag body 2 hardens while enclosing the workpiece, and the bag gripper 28 is able to grip the workpiece. The control device 4 also stops applying the high voltage to the high-voltage electrode 31, thereby softening the bag body 2 by decreasing the viscosity of the electroviscous fluid 29 inside the bag body 2. This softening of the bag body 2 releases the grip of the workpiece by the bag gripper 28.

[0068] The number of high-voltage electrodes 31 is not limited to 16; any number is acceptable as long as the electric field lines sufficiently penetrate the electroviscous fluid 29. The higher the electric field strength generated between the high-voltage electrodes 31, the greater the viscosity of the electroviscous fluid 29, for example, 2 kV / mm.

[0069] Figure 12 is a schematic cross-sectional view of the bag gripper 28 in the third embodiment along the line BB in Figure 11. In Figure 12, 31a is the anode of the high-voltage electrode 31, 31b is the cathode of the high-voltage electrode 31, and 33 are the electric field lines generated by the high-voltage electrode 31. When a high voltage is applied to the high-voltage electrode 31, the electric field lines 33 penetrate the electroviscous fluid 29, increasing the viscosity of the electroviscous fluid 29.

[0070] The arrangement of the anode 31a and cathode 31b of the high-voltage electrode 31 is not limited to the example in Figure 12; for example, the positions of the anode 31a and cathode 31b in Figure 12 may be swapped. In the example in Figure 12, the high-voltage electrode 31 is an iron rod, but it is not limited to this; for example, it may be a resin rod on which a conductive film is deposited by vapor-depositing metal. Alternatively, multiple conductive films may be deposited on a single high-voltage electrode 31, spaced apart from each other, with some of the conductive films serving as anodes and the remaining conductive films as cathodes. In the example in Figure 12, the shape of the high-voltage electrode 31 is cylindrical, but it is not limited to this; for example, it may be a hexagonal prism or a cross-shaped prism, but the smaller the gap between the high-voltage electrodes 31, the higher the viscosity of the electroviscous fluid 29 can be made. In the example shown in Figure 12, the high-voltage electrode 31 is an iron rod without a coating on its surface, but it is not limited to this. An insulating film may be applied to the surface, and forming an insulating film can prevent short circuits even if the high-voltage electrodes 31 come into contact with each other.

[0071] <Fourth Embodiment> Next, a fourth embodiment of this disclosure will be described. Components similar to those in the third embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. Figure 13 is a schematic longitudinal cross-sectional view of the bag gripper 34 in the fourth embodiment.

[0072] As shown in Figure 13, the bag gripper 34 in the fourth embodiment, like the third embodiment, comprises a bag body 2 and maintains the shape of the bag body 2 by electrostatic force. Unlike the third embodiment, the filling material inside the bag body 2 in the fourth embodiment is dielectric powder 35. Dielectric powder 35 is an example of a curable medium of this disclosure.

[0073] It is desirable that the dielectric powder 35 has high fluidity such that, after the bag 2 softens, the high-pressure electrode 31 can move to the front end of the bag 2 as far as possible by pushing away the dielectric powder 35 with the elastic force of the high-pressure electrode side elastic element 32. Such a fluid dielectric powder 35 is, for example, spherical powder. The dielectric powder 35 is preferably a material with a high dielectric constant, for example, an alumina sphere with a diameter of 1 mm.

[0074] In the third embodiment, the inside of the bag 2 is filled with an electroviscous fluid 29, and the electroviscous fluid 29 functions as an insulating oil for the high-voltage electrode 31 inside the bag 2. However, in the fourth embodiment, unlike the third embodiment, the filling medium other than the dielectric powder 35 filled in the bag 2 is air, so the inside of the bag 2 is insulated from the high-voltage electrode 31 by air, and the insulating properties tend to be lower than in the third embodiment. Therefore, the maximum allowable electric field strength that can be applied between the high-voltage electrodes 31 tends to be more limited than in the third embodiment. When the voltage applied to the high-voltage electrode 31 is particularly high, it is desirable that there are no protrusions on the surface of the high-voltage electrode 31 in order to prevent the occurrence of corona discharge. In the example of Figure 13, the shape of the tip of the high-voltage electrode 31 (the end opposite the base) has a constant diameter, but it is not limited to this, and may be a tapered shape that becomes narrower towards the tip, for example. In this case, the high-voltage electrode 31 will be able to push the dielectric powder 35 away more easily, but the electrostatic force at the tip when a high voltage is applied to the high-voltage electrode 31 will decrease, and the force that maintains the shape of the bag 2 will decrease.

[0075] Similar to the third embodiment, in the region of the bag 2 opposite to the base member 7, the guide mechanism 16 acts as an insulating plate to insulate the adjacent high-voltage electrodes 31.

[0076] In the example in Figure 13, the filling medium other than the dielectric powder 35 filled in the bag 2 is air, but it is not limited to this. Any insulating fluid that does not damage the bag 2, base member 7, sealing member 10, high-pressure electrode 31, or dielectric powder 35 may be used, such as nitrogen gas or silicone oil. When the same fluid as the ambient environment in which the bag gripper 34 operates is used as the filling medium other than the dielectric powder 35, unlike in the third embodiment, watertightness or airtightness is not required for the sealing between the bag 2 and the base member 7, and for the sealing between the base member 7 and the high-pressure electrode 31 by the sealing member 10. It is sufficient to ensure that the dielectric powder 35 does not leak out. However, in dusty environments, high-humidity environments, or ambient environments containing salt or harmful gases, sufficient watertightness or airtightness is required because the insulating properties may decrease. Also, if the dielectric powder 35 is a hygroscopic substance, sufficient watertightness or airtightness is required. On the other hand, when a fluid different from the ambient environment in which the bag gripper 34 operates is used as a filling medium other than the dielectric powder 35, the sealing between the bag 2 and the base member 7, and the sealing between the base member 7 and the high-voltage electrode 31 by the sealing member 10, must be airtight or watertight. By using a highly insulating fluid as a filling medium other than the dielectric powder 35, a higher voltage can be applied to the high-voltage electrode 31. Furthermore, by using a fluid with rust-preventive properties, such as rust-preventive oil, as a filling medium other than the dielectric powder 35, oxidation of the high-voltage electrode 31 or the dielectric powder 35 can be suppressed.

[0077] <Fifth Embodiment> Next, a fifth embodiment of the present disclosure will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. Figure 14 is a schematic longitudinal cross-sectional view of the bag gripper 36 in the fifth embodiment.

[0078] As shown in Figure 14, the bag gripper 36 in the fifth embodiment, like the first embodiment, has a magnetorheological fluid 8 sealed inside the bag body 2. However, unlike the first embodiment, the actuators that move the magnets 11 are not a single linear actuator 13, but multiple rotary actuators 37. Each rotary actuator 37 is provided for each magnet 11 and fixed to the housing 3.

[0079] The bag gripper 36 does not have a magnet fixing member 12 or a magnet-side elastic element 15, and the magnet 11 is directly fixed to the wire 38 of the rotary actuator 37, for example, by adhesive or heat shrink tubing. The magnet fixing member 12 may be placed between the magnet 11 and the wire 38, but in this case, when the magnet 11 moves to its maximum extent toward the tip of the cylindrical member 9, the tip of the magnet 11 will move away from the tip of the cylindrical member 9 by the length of the magnet fixing member 12, and it tends to become more difficult for magnetic field lines to pass to the tip of the bag 2.

[0080] The wire 38 is formed in a linear shape. The wire 38 is looped around a drive pulley 39 fixed to the drive shaft of the rotary actuator 37 and a driven pulley 40 fixed to the inside of the closed end of the cylindrical member 9. When the distance between the axes of the drive pulley 39 and the driven pulley 40 changes due to the cylindrical member 9 being pushed in by the workpiece, the wire 38 absorbs the change by slackening. The length of the wire 38 is preferably designed so that even when the magnet 11 moves to its maximum extent toward the rotary actuator 37, and the cylindrical member 9 is pushed to its maximum extent toward the rotary actuator 37 by the workpiece, the cylindrical member 9 is not subjected to magnetic force as much as possible. In the example in Figure 14, a linear wire 38 is used, but a belt may be used instead of the wire 38.

[0081] The drive pulley 39 rotates when driven by the rotary actuator 37. The driven pulley 40 rotates passively due to the movement of the wire 38 accompanying the rotation of the drive pulley 39. When the rotary actuator 37 is driven, the magnet 11 moves in a straight line via the wire 38. A smaller diameter of the driven pulley 40 allows the magnet 11 to move in a straight line further towards the tip of the bag 2, but a smaller diameter of the driven pulley 40 tends to increase the frictional force when the wire 38 moves. In the example in Figure 14, a free-rotating driven pulley 40 is used, but this is not the only option, and a hook mechanism, for example, may be used instead of the driven pulley 40.

[0082] The rotary actuator wiring 41 electrically connects the connecting member 5 and the rotary actuator 37. The control device 4 drives each rotary actuator 37 via the connecting member 5 and the rotary actuator wiring 41. Note that if the control device 4 is installed inside the bag gripper 36, the connecting member 5 does not need to be installed.

[0083] When the magnetorheological fluid 8 is made highly viscous to grip the workpiece with the bag gripper 36, the control device 4 applies a first electrical signal to the rotary actuator 37, causing the drive pulley 39 to rotate in a first direction and thereby move the wire 38. The control device 4 stops the drive pulley 39 when the magnet 11 reaches the tip of the cylindrical member 9. When the magnet 11 reaches the tip of the cylindrical member 9, the viscosity of the magnetorheological fluid 8 increases, and the workpiece 6 is gripped by the bag gripper 36.

[0084] On the other hand, when the viscosity of the magnetorheological fluid 8 is reduced to release the workpiece, the control device 4 applies a second electrical signal to the rotary actuator 37, causing the drive pulley 39 to rotate in a second direction opposite to the first direction, thereby moving the wire 38. The control device 4 stops the drive pulley 39 once the magnet 11 has completely detached from the cylindrical member 9. When the magnet 11 detaches from the cylindrical member 9, the viscosity of the magnetorheological fluid 8 decreases, and the grip on the workpiece 6 is released.

[0085] <Sixth Embodiment> Next, a sixth embodiment of the present disclosure will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. Figure 15 is a schematic longitudinal cross-sectional view of the bag gripper 42 in the sixth embodiment.

[0086] In the sixth embodiment, the bag gripper 42, like in the first embodiment, has a fluid sealed inside the bag body 2 while maintaining watertightness. However, unlike the first embodiment, the contents sealed inside the bag body 2 in the sixth embodiment are an aqueous sodium acetate solution 43. The aqueous sodium acetate solution 43 is an example of a curable medium of this disclosure. Furthermore, the configuration corresponding to the cylindrical member 9 and magnet 11 in the first embodiment is 16 heat pipes 44 in the sixth embodiment, and the configuration corresponding to the cylindrical member-side elastic element 14 in the first embodiment is a heat pipe-side elastic element 45 in the sixth embodiment. The heat pipe-side elastic element 45 is made of a spring, similar to the cylindrical member-side elastic element 14, and connects the guide mechanism 16 and the heat pipes 44.

[0087] The heat pipe 44 is cylindrical and made of iron. The heat pipe 44 is inserted through a communication hole in the base member 7. The space between the base member 7 and the heat pipe 44 is sealed by a sealing member 10 so that the communication hole is watertight. Inside the heat pipe 44 are a hot fluid channel 48 through which a hot fluid 46 flows and a cold fluid channel 49 through which a cold fluid 47 flows. The hot fluid channel 48 and the cold fluid channel 49 are each formed in a U shape.

[0088] One end of a hot fluid supply pipe 50 is connected to the inlet end of a hot fluid channel 48, and one end of a hot fluid discharge pipe 51 is connected to the outlet end. One end of a cold fluid supply pipe 52 is connected to the inlet end of a cold fluid channel 49, and one end of a cold fluid discharge pipe 53 is connected to the outlet end. The hot fluid 46 is stored in a hot fluid tank 54 and heated by a heater 56 attached to the hot fluid tank 54. The hot fluid 46 is maintained at a temperature above the melting point of the sodium acetate aqueous solution 43, for example, 90°C. The cold fluid 47 is stored in a cold fluid tank 55 and cooled by a cooler 57 attached to the cold fluid tank 55. The cold fluid 47 is maintained at a temperature below the melting point of the sodium acetate aqueous solution 43, for example, 20°C. The heater 56 is, for example, an electric heating element heater. The cooler 57 is, for example, a chilled water chiller.

[0089] The other end of the hot fluid supply pipe 50 is connected to the bottom of the hot fluid tank 54 via a hot fluid valve 58 and a hot fluid pump 60. The other end of the cold fluid supply pipe 52 is connected to the bottom of the cold fluid tank 55 via a cold fluid valve 59 and a cold fluid pump 61. The other end of the hot fluid discharge pipe 51 is connected to the top of the hot fluid tank 54. The other end of the cold fluid discharge pipe 53 is connected to the top of the cold fluid tank 55. When the hot fluid valve 58 is opened and the cold fluid valve 59 is closed, and the hot fluid pump 60 is driven, the hot fluid 46 circulates and the heat pipe 44 is heated. When the hot fluid valve 58 is closed and the cold fluid valve 59 is opened, and the cold fluid pump 61 is driven, the cold fluid 47 circulates and the heat pipe 44 is cooled.

[0090] The hardening trigger mechanism 65 consists of a hardening trigger driver 62 and a hardening trigger plate 63. The hardening trigger driver 62 is mounted on the housing 3. The hardening trigger driver 62 is, for example, a solenoid, an electrically or pneumatic linear actuator, or a rotary actuator having a cam mechanism on its output shaft. The hardening trigger plate 63 is supported by a hardening trigger plate support member 64 mounted on the base member 7. The hardening trigger plate 63 is a metal plate supported by the hardening trigger plate support member 64 in a bent state. When the hardening trigger driver 62 is driven via the connecting member 5 under the control of the control device 4, the hardening trigger plate 63 undergoes jump buckling.

[0091] Under the control of the control device 4, the hot fluid valve 58 and hot fluid pump 60 are driven via the connecting member 5, and the hot fluid 46 flows into the hot fluid channel 48, causing the sodium acetate aqueous solution 43 to reach a temperature above its melting point and become liquid. Subsequently, under the control of the control device 4, the hot fluid valve 58 and hot fluid pump 60 are stopped to cease the flow of the hot fluid 46, while the cold fluid valve 59 and cold fluid pump 61 are driven to allow the cold fluid 47 to flow into the cold fluid channel 49, thereby cooling the sodium acetate aqueous solution 43 to below its freezing point. After that, the cold fluid valve 59 and cold fluid pump 61 are stopped to cease the flow of the cold fluid 47. At this point, the sodium acetate aqueous solution 43 remains liquid due to the supercooling phenomenon. In this state, the bag 2 is pressed against the workpiece, so that the workpiece is wrapped in the bag 2.

[0092] Next, the control device 4 drives the hardening trigger driver 62 via the connecting member 5, causing it to jump onto the hardening trigger plate 63 and buckle, thereby applying an impact to the sodium acetate aqueous solution 43. The hot ice phenomenon associated with this impact rapidly hardens the sodium acetate aqueous solution 43, hardening the bag 2. As a result, the bag 2 hardens while enclosing the workpiece, and the bag gripper 42 can grip the workpiece. In other words, the heat pipe 44 and the hardening trigger mechanism 65 constitute the hardening section of the sixth embodiment. Note that the impact applied when pressing the bag 2 against the workpiece is kept to an extent that does not cause the sodium acetate aqueous solution 43 to exhibit the hot ice phenomenon.

[0093] The control device 4 drives the hot fluid valve 58 and the hot fluid pump 60, allowing the hot fluid 46 to flow through the hot fluid channel 48. This causes the sodium acetate aqueous solution 43 to reach a temperature above its melting point, softening the bag 2 and releasing the workpiece.

[0094] Here, the sodium acetate aqueous solution 43 is prepared, for example, by mass ratio, such that sodium acetate trihydrate is 10 parts to pure water. In order to shorten the time required for the bag 2 to harden, the sodium acetate aqueous solution 43, which is prone to supercooling, is used as the curing medium sealed inside the bag 2. Note that the curing medium is not limited to sodium acetate trihydrate; any fluid that is prone to supercooling can be used. Sodium thiosulfate pentahydrate can be given as an example of a fluid that is prone to supercooling. The temperatures of the hot fluid 46 and the cold fluid 47 are set according to the melting point of the curing medium and the heat resistance temperature of the workpiece. If it is not a problem for the bag 2 to harden for a certain amount of time, the curing medium may be a fluid that is not prone to supercooling, for example, pure water or liquid metal. In this case, the hardening trigger mechanism 65 does not need to be provided.

[0095] When a hardening medium that is solid at room temperature is sealed in a bag 2, the control device 4 drives the hot fluid valve 58 and the hot fluid pump 60, allowing the hot fluid 46 to flow through the hot fluid channel 48, causing the hardening medium to reach a temperature above its melting point and become liquid. Then, the workpiece is pressed into the bag 2, encasing it. Next, the control device 4 stops the hot fluid valve 58 and the hot fluid pump 60 to stop the flow of the hot fluid 46, while simultaneously driving the cold fluid valve 59 and the cold fluid pump 61 to allow the cold fluid 47 to flow through the cold fluid channel 49, cooling the hardening medium below its freezing point. Once the bag 2 has hardened, the cold fluid valve 59 and the cold fluid pump 61 are stopped to stop the flow of the cold fluid 47. As a result, the bag 2 hardens while encasing the workpiece, allowing the bag gripper 42 to grip the workpiece. To release the workpiece, the control device 4 drives the hot fluid valve 58 and the hot fluid pump 60, allowing the hot fluid 46 to flow into the hot fluid channel 48. This causes the curable medium to reach a temperature above its melting point and become liquid. As a result, the bag gripper 42 releases the workpiece.

[0096] When sealing a liquid curable medium in a bag 2 at room temperature, the workpiece is first pressed against the bag 2, enclosing it. Then, under the control of the control device 4, the cold fluid valve 59 and cold fluid pump 61 are driven, and cold fluid 47 is allowed to flow through the cold fluid channel 49, cooling the curable medium below its freezing point and hardening the bag 2. As a result, the bag 2 hardens while enclosing the workpiece, and the bag gripper 42 is able to grip the workpiece. To release the workpiece, under the control of the control device 4, the cold fluid valve 59 and cold fluid pump 61 are stopped to cease the flow of cold fluid 47, while the warm fluid valve 58 and warm fluid pump 60 are driven, allowing warm fluid 46 to flow through the warm fluid channel 48. This causes the curable medium to reach a temperature above its melting point and become liquid. This releases the workpiece from the bag gripper 42.

[0097] Although the heat pipe 44 has one flow path each for the hot fluid 46 and the cold fluid 47, it is not limited to this arrangement. Alternatively, only one flow path shared by the hot fluid 46 and the cold fluid 47 may be provided, and the fluid flowing through it may be switched by switching valves provided on the upstream and downstream sides of the heat pipe 44. The heat pipe 44 is made of iron, but it is not limited to this. For example, it may be made of aluminum or copper. A material with high thermal conductivity is desirable because it can change the temperature of the curable medium more quickly. The heat pipe 44 is cylindrical, but it is not limited to this. For example, it may be hexagonal. The hot fluid flow path 48 and the cold fluid flow path 49 are each formed in a U-shape, but they are not limited to this. For example, they may be formed in a shape where a U-shaped tube is wound spirally. It is desirable that the surface area in contact between the hot fluid 46 and the cold fluid 47 and the heat pipe 44, and the surface area in contact between the heat pipe 44 and the curable medium are as large as possible, because this allows the temperature of the curable medium to be changed more quickly.

[0098] [Modified examples of embodiments] This disclosure is not limited to the embodiments described herein, and various modifications can be made without departing from its spirit. Furthermore, the embodiments described above and the modifications shown below may be combined in any way, as long as they function properly.

[0099] For example, the bag gripper 26 in the second embodiment, the bag gripper 28 in the third embodiment, the bag gripper 34 in the fourth embodiment, and the bag gripper 36 in the fifth embodiment can be applied to the gripping system, jig system, and legged robot system exemplified in the first embodiment. [Industrial applicability]

[0100] The membrane bag composite of this disclosure has the effect of stably gripping or manipulating a wider variety of workpieces by increasing the deformable capacity of the bag, and can be applied to FA applications such as high-mix low-volume production, as well as service robots such as delivery robots. Furthermore, by improving the watertightness or airtightness of the bag, the membrane bag composite of this disclosure can also be applied to exploration robots in water or in places with thin air. [Explanation of Symbols]

[0101] 1, 26, 28, 34, 36, 42 Bag Gripper 2 bags 3 cabinets 4. Control device 5. Connecting Members 6 Work 7 Base member 8. Magnetoviscous fluids 9. Cylindrical member 10 sealing member 11 Magnets 11a N pole 11b S pole 12 Magnet fixing member 13 Linear Actuator 13A Main Unit 13B Mobile 14. Elastic element on the side of the cylindrical member 15. Elastic element on the magnet side 16 Guide mechanism 17 Magnetic field lines 18 Robot Arm 19. Hands 20 Robot support base 21 Two-finger gripper 22 2nd finger gripper nail area 23 Work in Progress 24-legged robot 25 Ground 27 Magnetic powder 29 Electroviscous Fluids 30 High-voltage power lines 31 High-voltage electrode 31a Anode 31b Cathode 32 High-pressure electrode side elastic element 33 Electric field lines 35 Dielectric powders 37 Rotary Actuator 38 wires 39 Drive pulley 40 Driven pulley 41 Rotary actuator wiring 43. Sodium acetate aqueous solution 44 Heat Pipes 45 Heat pipe side elastic element 46. ​​Hot fluid 47 Cold fluid 48. Hot fluid channel 49 Cold fluid channel 50 Hot fluid supply pipe 51 Hot fluid discharge pipe 52 Cold fluid supply pipe 53 Cold fluid discharge pipe 54 Hot fluid tank 55 Cold fluid tank 56 Warmer 57 Cooler 58. Hot fluid valve 59 Cold fluid valve 60 Hot fluid pump 61 Cold fluid pump 62. Hardening trigger drive 63 Hardening trigger plate 64 Hardened trigger plate support member 65. Hardening trigger mechanism

Claims

1. a flexible bag having an opening, the bag being filled with a hardenable medium made of a fluid or powder; a base member disposed to close the opening of the bag body, the base member having a communication hole that connects the inside and outside of the bag body; a hardened portion inserted into the communication hole so as to be movable in the direction of the central axis of the communication hole, The hardening unit hardens the hardenable medium to hold the bag body in a desired shape. Membrane bag complex.

2. The bag body conforms to the shape of the workpiece by a pressing force that presses the workpiece against the bag body. The membrane bag complex according to claim 1.

3. the curable medium is magnetic or dielectric; The hardening unit hardens the hardenable medium using magnetic or dielectric properties. The membrane bag complex according to claim 1 or 2.

4. The hardenable medium is magnetic; The hardening portion includes a magnet. The membrane bag complex according to claim 3 .

5. the hardenable medium is a magnetic fluid; The base member is configured so that the hardening portion can move while the watertightness or airtightness of the bag body is maintained. The membrane bag complex according to claim 4.

6. The hardenable medium is a magnetic powder. The membrane bag complex according to claim 4.

7. The curable medium has dielectric properties, The hardening portion includes an electrode. The membrane bag complex according to claim 3 .

8. the hardenable medium is an electrorheological fluid; The base member is configured so that the hardening portion can move while the watertightness or airtightness of the bag body is maintained. The membrane bag complex according to claim 7.

9. The curable medium is a dielectric powder. The membrane bag complex according to claim 7.

10. the hardenable medium is a fluid that hardens with a decrease in temperature; the base member is configured so that the hardening portion is movable while the watertightness or airtightness of the bag body is maintained, The hardening unit hardens the hardenable medium by lowering the temperature of the hardenable medium. The membrane bag complex according to claim 2.

11. The hardening unit hardens the hardenable medium by applying an impact to the hardenable medium in a supercooled state. The membrane bag complex according to claim 10.

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