Assist Device

Abstract

To provide a technique for reducing consumption of a gas on an artificial muscle.SOLUTION: An assist device comprises: a first artificial muscle which is attached to a space between two parts of a user, shrinks when an internal pressure increases and extends when the internal pressure decreases; a second artificial muscle which is attached to a space between two parts of a user different from a position of the first artificial muscle; and a pressure adjusting unit for adjusting an internal pressure of the first artificial muscle and second artificial muscle. The pressure adjusting unit comprises: a connection channel for coupling the first artificial muscle and second artificial muscle; a valve which is provided on the connection channel for switching a state of the connection channel between a communication state and a non-communication state; and a control part for switching a state of the valve according to at least one of the internal pressure of the first artificial muscle and the internal pressure of the second artificial muscle.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an assist device that assists a user's movements. [Background technology]

[0002] Patent Documents 1 and 2 disclose assist devices that support a user's movements using artificial muscles that expand and contract in response to internal pressure. Artificial muscles that use compressed gas as their power source are generally known as McKibben-type pneumatic artificial muscles, which have the property of shortening when internal pressure increases and extending when internal pressure decreases. That is, as the internal pressure of an artificial muscle increases, the internal space expands, increasing the width of the artificial muscle and decreasing its length. Conversely, as the internal pressure decreases, the internal space shrinks, decreasing the width of the artificial muscle and increasing its length. Furthermore, when an artificial muscle is stretched by an external force with its air supply port closed, the internal space of the artificial muscle shrinks, increasing the internal pressure and generating tension (contractile force) proportional to the amount of stretch. When the external force is reduced from the stretched state, the artificial muscle shortens due to the aforementioned contractile force, and the increased internal pressure of the artificial muscle decreases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-340852 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-148488 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the assist device of the prior art, the exhaust gas from the artificial muscle is released to the outside, making it difficult to reduce the amount of gas consumed. [Means for solving the problem]

[0005] The present disclosure has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, there is provided an assisting device that assists a user's movement. The assisting device includes: a first artificial muscle that is attached between two parts of the user and shortens when internal pressure increases and extends when the internal pressure decreases; a second artificial muscle that is attached between two parts different from the first artificial muscle; and a pressure regulating device that adjusts the internal pressure of the first artificial muscle and the second artificial muscle. The pressure regulating device includes a connecting flow path that connects the first artificial muscle and the second artificial muscle, a valve that is provided in the connecting flow path and can switch the connecting flow path between a connected state and a disconnected state, and a control unit that switches the state of the valve in response to at least one of the internal pressure of the first artificial muscle and the internal pressure of the second artificial muscle. The control unit is configured to perform an operation of switching the state of the valve to the communicating state in response to an increase in the internal pressure of the first artificial muscle, and accumulating exhaust gas from the first artificial muscle as auxiliary gas in the second artificial muscle, and an operation of switching the state of the valve to the communicating state in response to a decrease in the internal pressure of the first artificial muscle or an increase in the internal pressure of the second artificial muscle, and supplying the auxiliary gas accumulated in the second artificial muscle to the first artificial muscle. With this assist device, the valve switches the connecting flow path between the first and second artificial muscles between a connected state and a disconnected state, allowing gas to be exchanged between the first and second artificial muscles, reducing gas consumption. Also, it is possible to achieve both assistance by the first artificial muscle and assistance by the second artificial muscle. (2) In the above assist device, the pressure adjustment device includes a gas supply source that supplies gas to the first artificial muscle, and the valve is connected between the gas supply source and the first artificial muscle and is configured to be switchable between a plurality of states including an air supply state in which the gas is supplied to the first artificial muscle and an exhaust state in which the gas is exhausted from the first artificial muscle, and the connection flow path connects an air supply pipe that connects the valve and the first artificial muscle and the valve and the second artificial muscle, and when the internal pressure of the first artificial muscle increases, exhaust gas that has reached the valve from the first artificial muscle is supplied to the second artificial muscle. The aforementioned and an exhaust pipe for accumulating the auxiliary gas as auxiliary gas, and the pressure adjustment device may further include an auxiliary connection pipe that connects the second artificial muscle and the air supply pipe and supplies the auxiliary gas from the second artificial muscle to the first artificial muscle via the air supply pipe when the internal pressure of the first artificial muscle decreases or when the internal pressure of the second artificial muscle increases. This assist device can reuse the exhaust gas from the first artificial muscle as assist gas, reducing gas consumption, and also provides auxiliary assistance from the second artificial muscle. (3) In the above assist device, the exhaust pipe may have a first check valve provided to allow gas to flow unidirectionally from the valve toward the second artificial muscle, and the auxiliary connecting pipe may have a second check valve provided to allow gas to flow unidirectionally from the second artificial muscle toward the air supply pipe. According to this assist device, the exhaust gas from the first artificial muscle can be accumulated as auxiliary gas in the second artificial muscle with a simple configuration, and the accumulated auxiliary gas can be supplied from the second artificial muscle to the first artificial muscle. (4) In the above assisting device, the first artificial muscle may be configured to be attached between the shoulders and lower legs of the user via the back of the user to assist the user's lower back, and the second artificial muscle may be configured to be attached between the shoulders and wrists of the user to assist the user's arms. This assist device can assist both the user's waist and arms. (5) The assisting device may further include a shoulder orthosis attached to the shoulder of the user and to which the upper end of the first artificial muscle is connected, a lower end connector to which the lower end of the first artificial muscle is connected at a height position corresponding to a part of the user below the waist, a lower limb orthosis attached to the lower limb of the user below the lower end connector, and a connecting belt connecting the lower end connector and the lower limb orthosis. According to this assist device, the first artificial muscle connected between the shoulder orthosis and the lower end connector can assist the user's lower back, and the lower end of the first artificial muscle can be stabilized by the connecting belt. (6) The assist device may further include an elastic belt that applies tension between the shoulder brace and the lower end connector by connecting them, and the lower end connector may not be fixed to the user but may be positioned by the elastic belt and the connecting belt. According to this assist device, the elastic belt pulls the lower end connector toward the shoulder brace, so the position of the lower end connector can be stabilized. (7) The assist device may further include a first pressure sensor that detects a first pressure corresponding to the internal pressure of the first artificial muscle, and a second pressure sensor that detects a second pressure corresponding to the internal pressure of the second artificial muscle. The control unit may be configured to execute: (i) a first control that opens the valve when the second pressure becomes equal to or greater than a first threshold value, thereby bringing the connecting flow path into the connected state, and closes the valve when the second pressure becomes equal to or less than a second threshold value that is smaller than the first threshold value; and (ii) a second control that opens the valve when a difference obtained by subtracting the second pressure from the first pressure becomes greater than a difference threshold value, thereby bringing the connecting flow path into the connected state, and closes the valve when the first pressure becomes equal to or less than the second pressure. According to this assist device, the connecting flow path between the first artificial muscle and the second artificial muscle is opened or closed depending on the internal pressure of the first artificial muscle and the second artificial muscle, so that it is possible to simultaneously assist the waist and the arms while exchanging gas between the first artificial muscle and the second artificial muscle. (8) In the above assist device, the control unit may be configured to issue a warning when the second pressure falls below a lower limit value that is smaller than the second threshold value, and the pressure adjustment device may further include a gas supply source that increases the internal pressure of the connecting flow path. According to this assist device, a warning is issued when the internal pressure of the second artificial muscle drops, and the user can increase the internal pressure of the connecting flow path by using the gas supply source in response to this warning. (9) In the above assist device, the control unit may adjust the opening and closing of the valve so that the first pressure is lower than the second pressure when the internal pressure of the connecting flow path is increased using the gas supply source. With this assist device, the first pressure is lower than the second pressure, so the assist force on the user's lower back when bending is weak, and there is little resistance when bending, making it easier to move. [Brief explanation of the drawings]

[0007] [Figure 1] 10A and 10B are explanatory diagrams showing a bending motion in which a user wearing the assist device picks up and lowers an object. [Figure 2] FIG. 10 is an explanatory diagram showing an extension movement in which a user wearing the assist device lifts an object. [Figure 3] FIG. 4 is a system diagram showing an internal pressure adjustment system of the assist device. [Figure 4] FIG. 10 is an explanatory diagram showing the configuration of an assist device according to a second embodiment. [Figure 5] FIG. 10 is an explanatory diagram showing the assist device attached to the back of a user. [Figure 6] FIG. 10 is a system diagram showing an internal pressure adjustment system of an assist device according to a second embodiment. [Figure 7] FIG. 10 is an explanatory diagram showing the contents of a first control of a valve in the second embodiment. [Figure 8] FIG. 10 is an explanatory diagram showing the content of a second control of the valve in the second embodiment. [Figure 9] FIG. 10 is an explanatory diagram showing a bending operation during lifting in the second embodiment. [Figure 10] FIG. 10 is an explanatory diagram showing an extension operation during lifting in the second embodiment. [Figure 11] FIG. 10 is an explanatory diagram showing a bending operation when being lowered in the second embodiment. [Figure 12] FIG. 10 is an explanatory diagram showing a load releasing operation in the second embodiment. [Figure 13] FIG. 10 is an explanatory diagram showing the extension movement after the load is released in the second embodiment. [Figure 14] 6 is a graph showing an example of changes in the first pressure and the second pressure in accordance with the movement of the user. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: FIG. 1 is an explanatory diagram showing a bending motion in which a user wearing an assisting device 100 according to a first embodiment of the present disclosure lowers an object PB, and FIG. 2 is an explanatory diagram showing an extension motion in which an object PB is lifted up.

[0009] The assist device 100 includes a shoulder orthosis 110 attached to the shoulders of a user, a lower limb orthosis 120 attached to the lower limbs of the user, a first artificial muscle 130 that connects the shoulder orthosis 110 and the lower limb orthosis 120 via the user's back, and a pressure adjustment device 140 that supplies gas to the first artificial muscle 130 to adjust the internal pressure of the first artificial muscle 130. The assist device 100 further includes a wrist orthosis 150 attached to the wrists of the user, and a second artificial muscle 160 that connects the shoulder orthosis 110 and the wrist orthosis 150. The wrist orthosis 150 is attached to the right wrist and the left wrist, respectively, and a second artificial muscle 160 for the right arm and a second artificial muscle 160 for the left arm are connected to the wrist orthosis 150.

[0010] In this embodiment, the shoulder orthosis 110 is a belt-like orthosis and is fixed to the shoulder of the user. The lower limb orthosis 120 can also be a belt-like orthosis. In this embodiment, the lower limb orthosis 120 is worn on the thigh. The wrist orthosis 150 can be a belt-like orthosis, or can be made of metal fittings. The wrist orthosis 150 preferably has an orthosis engagement portion that engages with an object engagement portion provided on the object PB. Such an orthosis engagement portion can be realized by, for example, a hook-like metal fitting. If the wrist orthosis 150 is configured to engage with the object PB, the force of the second artificial muscle 160 is directly transmitted to the object PB, thereby reducing the force required for the user to grasp the object PB with their hands.

[0011] The first artificial muscle 130 is an artificial muscle that has the characteristic of shortening when the internal pressure increases and extending when the internal pressure decreases. That is, when gas is supplied to the inside of the first artificial muscle 130 and the internal pressure increases, the internal space expands, the width of the artificial muscle increases, and the length decreases. On the other hand, when the inside of the first artificial muscle 130 is evacuated and the internal pressure decreases, the internal space shrinks, the width of the artificial muscle decreases, and the length increases. Furthermore, when the first artificial muscle 130 is extended by an external force with the gas supply port of the first artificial muscle 130 closed, the internal space of the first artificial muscle 130 becomes smaller, so the internal pressure increases and a tension (contractile force) proportional to the amount of extension is generated. When the external force is weakened from the extended state, the artificial muscle shortens due to the contractile force, and the increased internal pressure of the artificial muscle decreases. The same is true for the second artificial muscle 160.

[0012] In this embodiment, the pressure adjustment device 140 is attached to the back of the user while being connected to the shoulder orthosis 110, and is connected to the first artificial muscle 130 and the second artificial muscle 160. However, the location where the pressure adjustment device 140 is attached is arbitrary.

[0013] In this embodiment, the first artificial muscle 130 is attached between the user's shoulders and lower legs via the user's back, and is configured to assist the user's waist. The second artificial muscle 160 is attached between the user's shoulders and wrists, and is configured to assist the user's arms. However, the first artificial muscle 130 may be attached to two parts other than the shoulders and lower legs. For example, the first artificial muscle 130 may be attached between the chest and buttocks, or between the waist and ankles. When the user is standing upright, the two parts to which the first artificial muscle 130 is attached are preferably at different heights in the direction of gravity. Similarly, the second artificial muscle 160 may be attached to two parts other than the shoulders and wrists.

[0014] The state in FIG. 1 shows a bending operation in which a user lifts up an object PB and then lowers it. In this bending operation, the first artificial muscle 130 is extended by exhausting air from the first artificial muscle 130 and decreasing the internal pressure. The state in FIG. 2 shows an extension operation in which a user lifts up the object PB. In this extension operation, the first artificial muscle 130 is shortened by supplying gas to the first artificial muscle 130 and increasing the internal pressure. The movement of the second artificial muscle 160 will be described later.

[0015] 3 is a system diagram showing the internal pressure adjustment system of the assist device 100. The pressure adjustment device 140 has a control unit 200 and an air supply / exhaust system 300. The air supply / exhaust system 300 has a valve 310 that can be switched between multiple states, which will be described later, a gas source connection pipe 320, an exhaust pipe 330, and an air supply pipe 340.

[0016] The gas source connecting pipe 320 is connected to a gas supply source 322 that supplies gas to the first artificial muscle 130, and a regulator 324 is installed between the gas supply source 322 and the valve 310. In this embodiment, the gas supply source 322 is an air tank. The air tank contains high-pressure compressed air, and the air is reduced to a predetermined pressure by the regulator 324 and supplied to the valve 310. The gas supply source 322 may include an air compressor. The gas supply source 322 may also supply a compressed gas other than air, such as carbon dioxide. The gas source connecting pipe 320 is connected to a first port P1 of the valve 310.

[0017] The exhaust pipe 330 is a pipe for discharging air from inside the first artificial muscle 130, and is connected to a speed controller 332, a relief valve 334, and a buffer tank 336 in this order. However, the speed controller 332, the relief valve 334, and the buffer tank 336 can be omitted. The exhaust pipe 330 is connected to a third port P3 of the valve 310. This third port P3 is a so-called exhaust port or return port.

[0018] The air supply pipe 340 is connected to the manifold 132 of the first artificial muscle 130. The manifold 132 is in communication with the internal spaces of the multiple muscle members 134 that make up the first artificial muscle 130. A pressure sensor 342 that detects the internal pressure of the first artificial muscle 130 is installed in the air supply pipe 340. The air supply pipe 340 is connected to a second port P2 of the valve 310. This second port P2 is a so-called B port.

[0019] A branch exhaust pipe 350 that connects the exhaust pipe 330 and the second artificial muscle 160 is connected to the exhaust pipe 330. In this embodiment, the branch exhaust pipe 350 is connected to a pipe section of the exhaust pipe 330 between the relief valve 334 and the buffer tank 336. This branch exhaust pipe 350 can be considered to be part of the exhaust pipe 330. A first check valve 352 is provided in the branch exhaust pipe 350 to allow gas to flow unidirectionally from the exhaust pipe 330 toward the second artificial muscle 160. Although an electrically operated on-off valve may be used instead of the first check valve 352, using the first check valve 352 has the advantage of simplifying the configuration and control. The exhaust pipe 330, including the branch exhaust pipe 350, has the function of accumulating exhaust gas from the first artificial muscle 130 as auxiliary gas in the second artificial muscle 160 when the internal pressure of the first artificial muscle 130 increases.

[0020] A relief valve 334 is provided in the exhaust pipe 330, so the internal pressure of the buffer tank 336 and the second artificial muscle 160 is kept below the set pressure of the relief valve 334. The set pressure of the relief valve 334 is set to a value below the upper limit of a reference pressure range, which will be described later. A first check valve 352 is provided between the buffer tank 336 and the second artificial muscle 160, so that when the internal pressure of the second artificial muscle 160 drops below the internal pressure of the buffer tank 336, the gas accumulated in the buffer tank 336 is supplied to the second artificial muscle 160, increasing the internal pressure of the second artificial muscle 160. However, the relief valve 334 and the buffer tank 336 can be omitted. However, if the buffer tank 336 is provided, it is possible to replenish gas from the buffer tank 336 to the second artificial muscle 160 when the internal pressure of the second artificial muscle 160 drops, and the amount of gas consumed can be reduced.

[0021] An auxiliary connecting pipe 360 that connects the air supply pipe 340 and the second artificial muscle 160 is connected to the air supply pipe 340. A second check valve 362 is provided in the auxiliary connecting pipe 360 to allow gas to flow unidirectionally from the air supply pipe 340 toward the second artificial muscle 160. Although an electrically operated on-off valve may be used instead of the second check valve 362, using the second check valve 362 has the advantage of simplifying the configuration and control. The auxiliary connecting pipe 360 has the function of supplying auxiliary gas that has accumulated in the second artificial muscle 160 from the second artificial muscle 160 to the first artificial muscle 130 when the internal pressure of the first artificial muscle 130 drops.

[0022] The branch exhaust pipe 350 and the auxiliary connecting pipe 360 join at the joining position MP and are then connected to two second artificial muscles 160. A branch pipe 370 between the joining position MP and the second artificial muscles 160 functions as a piping section common to both the branch exhaust pipe 350 and the auxiliary connecting pipe 360.

[0023] In this embodiment, the valve 310 is a double solenoid type, three-position closed center type, five-port solenoid valve. However, the fourth port P4 and the fifth port P5 are unused and therefore sealed. The fourth port P4 is the so-called A port, and the fifth port P5 is the so-called second exhaust port or return port.

[0024] Valve 310 can be switched into one of three states: (1) Air supply status: The air supply state is a state in which gas is supplied to the first artificial muscle 130. In this air supply state, the gas source connection pipe 320 and the air supply pipe 340 are in communication with each other, and the exhaust pipe 330 is closed. The air supply state corresponds to the valve position in which the solenoid on the right side of the valve 310 is energized. This air supply state can also be called the "air supply position." (2) Exhaust condition: The exhaust state is a state in which exhaust is performed from the first artificial muscle 130. This exhaust state is a state in which the exhaust pipe 330 and the air supply pipe 340 are made to communicate with each other and the gas source connection pipe 320 is closed. Actually, the first port P1 connected to the gas source connection pipe 320 is in a state of communicating with the fourth port P4, but since the fourth port P4 is sealed, the gas source connection pipe 320 is also in a closed state. The exhaust state corresponds to the valve position in which the solenoid on the left side of the valve 310 is energized. It is also possible to call this exhaust state the "exhaust position". (3) Holding state: In the holding state, the supply and exhaust of the artificial muscle are stopped. This holding state is a state in which the gas source connection pipe 320, the exhaust pipe 330, and the air supply pipe 340 are all closed. Actually, all five of the P1 to P5 of the valve 310 are in a closed state. The holding state corresponds to the intermediate position in which the energization of the solenoids on both sides of the valve 310 is cut off. It is also possible to call this holding state the "holding position".

[0025] The control unit 200 executes control to switch the state of the valve 310 according to the internal pressure of the first artificial muscle 130 detected by the pressure sensor 342. Specifically, the control unit 200 executes the following controls C1 to C3. <Control C1> When Pm < Pr - α, the valve 310 is switched to the air supply state. <Control C2> When Pm > Pr + β, the valve 310 is switched to the exhaust state. <Control C3> When Pr - α ≤ Pm ≤ Pr + β, the valve 310 is switched to the holding state. Here, Pm is the detected pressure detected by the pressure sensor 342, Pr is a preset reference pressure, and α and β are allowable pressure differences. Note that α and β may be set to different values from each other, or may be set to the same value. In the following description, the range from Pr - α to Pr + β is called the "reference pressure range", Pr - α is called the "lower limit value", and Pr + β is called the "upper limit value". Also, the detected pressure Pm is also called the "internal pressure Pm of the artificial muscle 130".

[0026] The above-described controls C1 to C3 are controls that switch the state of the valve 310 according to the detected pressure Pm, with a predetermined reference pressure range Pr-α to Pr+β as the target control range. By executing this control, the internal pressure Pm of the first artificial muscle 130 can be adjusted to fall within the reference pressure range as much as possible.

[0027] Of the above-described controls C1 to C3, only controls C1 and C2 may be executed without executing control C3. Even in this case, by executing controls C1 and C2, the state of the valve 310 can be switched according to the detected pressure Pm, with the reference pressure range Pr-α to Pr+β set as the target control range. However, by executing control C3, the internal pressure Pm of the first artificial muscle 130 can be more easily kept within the reference pressure range. Furthermore, in the holding state, some of the gas inside the first artificial muscle 130 is discharged, but not all of it, which makes it possible to improve the consumption of the gas supplied from the gas supply source 322. When control C3 is not executed, a three-port valve or a four-port valve may be used as the valve 310.

[0028] Furthermore, the control unit 200 may control the valve 310 using control content other than that described above. For example, the control unit 200 may control the valve 310 in response to a command from a user, without using the pressure sensor 342. However, as described above, controlling the valve 310 using only the internal pressure of the first artificial muscle 130 detected by the pressure sensor 342 has the advantage of improving the operability of the assist with a simple device configuration.

[0029] In the bending operation shown in FIG. 1, when the internal pressure of the first artificial muscle 130 increases as the first artificial muscle 130 extends, the valve 310 switches to an exhaust state, and gas is discharged from inside the first artificial muscle 130. This exhaust gas passes through the exhaust pipe 330 and the branch exhaust pipe 350 shown in FIG. 3 and is accumulated as auxiliary gas in the buffer tank 336 and the second artificial muscle 160. At this time, the internal pressure of the second artificial muscle 160 increases, causing the second artificial muscle 160 to contract, assisting the user in holding the object PB. In addition, the branch exhaust pipe 350 is provided with a relief valve 334, which allows the first artificial muscle 130 to be sufficiently exhausted. The set pressure of the relief valve 334 is set to a value less than the upper limit value Pr+β of the reference pressure range described above. In addition, the set pressure of the relief valve 334 is preferably set to a value equal to or less than the reference pressure Pr and equal to or greater than the lower limit value Pr-α of the reference pressure range. This makes it possible to reduce the amount of gas consumed while keeping the internal pressure of the first artificial muscle 130 within the reference pressure range as much as possible.

[0030] 2, as the first artificial muscle 130 shortens, its internal pressure decreases, so the valve 310 switches to an air supply state, and gas is supplied from the gas supply source 322 to the first artificial muscle 130. Furthermore, when the second artificial muscle 160 is stretched to lift the object PB, the pressure of the auxiliary gas accumulated in the second artificial muscle 160 increases, and this auxiliary gas is supplied to the first artificial muscle 130. In this way, the auxiliary gas accumulated in the second artificial muscle 160 is supplied from the second artificial muscle 160 to the first artificial muscle 130 in response to a decrease in the internal pressure of the first artificial muscle 130 or an increase in the internal pressure of the second artificial muscle 160.

[0031] It is preferable that the user stretch the second artificial muscle 160 by raising his / her upper body without using the strength of his / her arms to lift the object PB. As described above, the wrist orthosis 150 is engaged with the object PB, so that the object PB can be lifted by raising his / her upper body without using the strength of his / her arms. At this time, the second artificial muscle 160 is stretched by the weight of the object PB and acts as a kind of pump, which can increase the pressure of the auxiliary gas inside the second artificial muscle 160. As a result, the auxiliary gas with increased pressure can be supplied to the first artificial muscle 130 and used to increase the internal pressure of the first artificial muscle 130.

[0032] The exhaust pipe 330 and the air supply pipe 340 in the first embodiment correspond to a connecting flow path that connects the first artificial muscle 130 and the second artificial muscle 160. The valve 310 corresponds to a valve that can switch the connecting flow path between the first artificial muscle 130 and the second artificial muscle 160 between a connected state and a disconnected state. That is, in the air supply state described above, communication between the exhaust pipe 330 and the air supply pipe 340 is blocked, so the connecting flow path formed by the exhaust pipe 330 and the air supply pipe 340 is in a disconnected state. In addition, in the exhaust state described above, the exhaust pipe 330 and the air supply pipe 340 are connected, so the connecting flow path formed by the exhaust pipe 330 and the air supply pipe 340 is in a connected state.

[0033] As described above, in the first embodiment, the valve 310 switches the connecting flow path between the first artificial muscle 130 and the second artificial muscle 160 between a connected state and a disconnected state, allowing gas to be exchanged between the first artificial muscle 130 and the second artificial muscle 160, thereby reducing gas consumption. In addition, both assistance by the first artificial muscle 130 and assistance by the second artificial muscle 160 can be achieved.

[0034] Furthermore, in the first embodiment, exhaust gas from the first artificial muscle 130 is accumulated as auxiliary gas in the second artificial muscle 160, and the auxiliary gas is supplied from the second artificial muscle 160 to the first artificial muscle 130 when the internal pressure of the first artificial muscle 130 decreases or when the internal pressure of the second artificial muscle 160 increases. Therefore, the exhaust gas from the first artificial muscle 130 can be reused as auxiliary gas, and gas consumption can be reduced. Also, auxiliary assistance by the second artificial muscle 160 can be realized. Furthermore, when a replaceable gas cylinder is used as the gas supply source 322, it is possible to reduce the frequency of replacing the cylinder.

[0035] B. Second embodiment: 4 is an explanatory diagram showing a state in which a user wearing the assisting device 400 of the second embodiment is standing upright. This state is the state before the user lifts up an object PB that is on a base BS.

[0036] The assist device 400 includes a shoulder orthosis 410 attached to the shoulders of a user, a lower limb orthosis 420 attached to the lower limbs of the user, a first artificial muscle 430 connected between the shoulder orthosis 410 and a lower end connector 490 via the user's back, a wrist orthosis 450 attached to the wrists of the user, a second artificial muscle 460 connected between the shoulder orthosis 410 and the wrist orthosis 450, and a pressure adjustment device 440 that adjusts the internal pressure of the first artificial muscle 430 and the second artificial muscle 460. The wrist orthosis 450 is attached to the right and left wrists, respectively, and a second artificial muscle 460 for the right arm and a second artificial muscle 460 for the left arm are connected to the wrist orthosis 450, respectively. The lower limb orthosis 420 includes a first orthosis 421 attached to the thighs of the user and a second orthosis 422 attached to the feet of the user. The first orthosis 421 and the second orthosis 422 are also attached to the right and left feet, respectively.

[0037] The upper end of the first artificial muscle 430 is connected to the shoulder orthosis 410, and the lower end is connected to a lower end connector 490. The shoulder orthosis 410 and the lower end connector 490 are further connected by an elastic belt 480 that stretches. That is, the shoulder orthosis 410 and the lower end connector 490 are connected by both the first artificial muscle 430 and the elastic belt 480. The elastic belt 480 applies tension between the shoulder orthosis 410 and the lower end connector 490. A non-elastic connecting belt 470 is provided between the lower end connector 490 and the second orthosis 422 on the foot. The connecting belt 470 is guided without being constrained by the first orthosis 421 on the thigh, passes through the first orthosis 421, and is fixed to the second orthosis 422 attached to the left and right feet.

[0038] FIG. 5 is an explanatory diagram showing the assist device 400 worn on the back of a user. The lower end connector 490 has a connector body 492 and a pin 494, with a gap between the connector body 492 and the pin 494. The connecting belt 470 is arranged so as to pass through the gap between the connector body 492 and the pin 494. In other words, the lower end connector 490 functions as a guide member that guides the connecting belt 470 without restraining it. Both ends of the connecting belt 470 are fixed to a second orthosis 422L worn on the left foot and a second orthosis 422R worn on the right foot. The connecting belt 470 stabilizes the lower end of the first artificial muscle 430. The lower end connector 490 is not fixed to the user's body part and is positioned by the elastic belt 480 and the connecting belt 470.

[0039] The lower end connector 490 is attached to a buttocks pad 495. The buttocks pad 495 and the lower end connector 490 are not fixed to the user's body part. The buttocks pad 495 is provided to stabilize the position of the lower end connector 490 by contacting the user's buttocks. As described above, the shoulder brace 410 and the lower end connector 490 are connected by an elastic belt 480. The elastic belt 480 pulls the lower end connector 490 toward the shoulder brace 410, thereby stabilizing the position of the lower end connector 490. In addition, the elastic belt 480 has the function of generating tension between the shoulder brace 410 and the lower end connector 490 when the user returns from a bent waist position to the upright position shown in FIG. 4, thereby assisting the user's waist. 5, two elastic belts 480 are provided, but three or more elastic belts 480 may be provided, or only one wide elastic belt 480 may be provided. Note that buttocks pad 495 and elastic belt 480 may be omitted.

[0040] In this way, the first artificial muscle 430 is indirectly connected to the second orthosis 422, which is the lower limb orthosis 420, via the connecting belt 470. However, the connecting belt 470 may be omitted, and the first artificial muscle 430 may be directly connected to the lower limb orthosis 420. In either case, the first artificial muscle 430 is preferably attached between the user's shoulders and lower limbs via the user's back, and configured to assist the user's lower back.

[0041] 4, the second artificial muscle 460 is configured to be worn between the shoulder and wrist of a user to assist the user's arm. In the second embodiment, the first artificial muscle 430 and the second artificial muscle 460 are also artificial muscles that have the property of shortening when the internal pressure increases and their diameters expand, and extending when the internal pressure decreases and their diameters contract.

[0042] In the second embodiment, the wrist orthosis 450 also preferably has an orthosis engagement portion that engages with the object engagement portion EG provided on the object PB. Such an orthosis engagement portion can be realized, for example, by a hook-shaped metal fitting. If the wrist orthosis 450 is configured to engage with the object PB, the force of the second artificial muscle 460 is transmitted directly to the object PB, thereby reducing the force required for the user to grasp the object PB with their hands.

[0043] FIG. 6 is a system diagram showing an internal pressure adjustment system of the assist device 400 of the second embodiment. In FIG. 6, the second artificial muscles 460 are distinguished as a second artificial muscle 460R for the right arm and a second artificial muscle 460L for the left arm. However, when this distinction is unnecessary, they are simply referred to as the "second artificial muscles 460." The pressure adjustment device 440 has a control unit 500 and an air supply / exhaust system 600. The air supply / exhaust system 600 has a valve 610 that can be switched between an open state and a closed state, an air supply pipe 630, and an exhaust pipe 640. The air supply pipe 630 connects the valve 610 and the second artificial muscle 460. The exhaust pipe 640 connects the valve 610 and the first artificial muscle 430. In other words, the air supply pipe 630 and the exhaust pipe 640 form a connecting flow path that connects the first artificial muscle 430 and the second artificial muscle 460. The exhaust pipe 640 is provided with a first pressure sensor 642 that detects a first pressure corresponding to the internal pressure of the first artificial muscle 430. The air supply pipe 630 is provided with a second pressure sensor 632 that detects a second pressure corresponding to the internal pressure of the second artificial muscle 460.

[0044] The air supply and exhaust system 600 further includes a branch pipe 650 connected to the two air supply pipes 630, a gas supply path 620 connected to the two air supply pipes 630 via the branch pipe 650, and a gas supply source 622 connected to the gas supply path 620. The gas supply path 620 is provided with a check valve 624 that prevents backflow of gas from the air supply pipe 630 to the gas supply source 622. The gas supply source 622 sends air toward the two air supply pipes 630 via the branch pipe 650 to increase the internal pressure of the second artificial muscle 460. Because the air supply and exhaust system 600 does not have an exhaust system to the outside, gas inside the air supply and exhaust system 600 decreases only through leakage. Therefore, the gas supply source 622 supplies air to compensate for leaked gas. In the second embodiment, the gas supply source 622 is a manual pump that is manually operated by a user. An air compressor, an air tank containing compressed air, or a tank containing compressed gas other than air, such as carbon dioxide, can also be used as the gas supply source 622. However, a manual pump has the advantage of being lightweight and not requiring the tank to be replaced.

[0045] Valve 610 is a normally closed two-port solenoid valve. That is, when the solenoid is not energized, valve 610 is closed, blocking the flow path between air intake pipe 630 and exhaust pipe 640 and creating a non-communicating state. On the other hand, when the solenoid is energized, valve 610 is opened, creating a communication path between air intake pipe 630 and exhaust pipe 640.

[0046] The control unit 500 is configured to execute the following two controls regarding the opening and closing of the valve 610. <First control> (1) Open condition A1: Pt1≦P2 (2) Closing condition A2: P2≦Pt2 Here, P2 is the second pressure measured by the second pressure sensor 632, Pt1 is a preset first threshold, and Pt2 is a second threshold that is smaller than the first threshold Pt1. When the opening condition A1 is satisfied, the valve 610 is switched from closed to open, and then when the closing condition A2 is satisfied, the valve 610 is switched from open to closed. Once the valve 610 is opened by the opening condition A1, it is maintained in the open state until the closing condition A2 is satisfied.

[0047] <Second control> (1) Open condition B1: P1-P2≧ΔPt (2) Closing condition B2: P1≦P2 Here, P1 is the first pressure measured by the first pressure sensor 642, P2 is the second pressure measured by the second pressure sensor 632, and ΔPt is a preset difference threshold. When the opening condition B1 is satisfied, the valve 610 is switched from closed to open, and then when the closing condition B2 is satisfied, the valve 610 is switched from open to closed. Also, once the valve 610 is opened by the opening condition B1, it is maintained in the open state until the closing condition B2 is satisfied.

[0048] FIG. 7 is an explanatory diagram showing the details of the first control described above, and FIG. 8 is an explanatory diagram showing the details of the second control. In the first control shown in FIG. 7, the valve 610 is normally closed, and when the opening condition A1 is satisfied, the valve 610 is switched from closed to open, and thereafter, when the closing condition A2 is satisfied, the valve 610 is switched from open to closed. In the second control shown in FIG. 8, the valve 610 is normally closed, and when the opening condition B1 is satisfied, the valve 610 is switched from closed to open, and thereafter, when the closing condition B2 is satisfied, the valve 610 is switched from open to closed. In either control, the determination pressures for the opening condition and the closing condition of the valve 610 are set to have a differential.

[0049] In actual operation, the valve 610 switches from closed to open in the following cases. For example, when the second artificial muscle 460 assisting the arm is extended to lift the object PB, the second pressure P2, which is the internal pressure of the second artificial muscle 460, increases. This satisfies the opening condition A1, Pt1≦P2, and the valve 610 switches from closed to open. As a result, gas is supplied from the second artificial muscle 460 to the first artificial muscle 430, increasing the internal pressure of the first artificial muscle 430, thereby increasing the assisting force of the first artificial muscle 430 on the waist. Furthermore, even if the internal pressure of the second artificial muscle 460 decreases for some reason, the opening condition B1, P1−P2≧ΔPt, is also satisfied, and the valve 610 switches from closed to open. In this case, gas is collected from the first artificial muscle 430 to the second artificial muscle 460, increasing the internal pressure of the second artificial muscle 460, preventing an excessive decrease in the assisting force of the arm provided by the second artificial muscle 460.

[0050] Preferably, the control unit 500 is further configured to issue a warning when the second pressure P2 measured by the second pressure sensor 632 falls below a lower limit pressure Pb, which is lower than the second threshold value Pt2. This warning can be notified to the user, for example, by sound or a lamp. The user can increase the internal pressure of the air intake pipe 630 by using the gas supply source 622 in response to the warning, thereby preventing the internal pressure of the air intake and exhaust system 600 from decreasing excessively. Furthermore, it is preferable that the control unit 500 stop issuing the warning when the internal pressure of the air intake pipe 630 increases due to use of the gas supply source 622 to reach the reference pressure Pref1 and when the internal pressure of the exhaust pipe 640 increases to reach the reference pressure Pref2. The user can stop pressurizing the air intake pipe 630 by using the gas supply source 622 in response to the warning being stopped.

[0051] The conditions for the warning generation / stop control by the control unit 500 when pressurizing using the gas supply source 622 described above are as follows. (1) Warning occurrence condition D1: P2≦Pb Here, Pb is a preset lower limit pressure. (2) Warning stop condition D2: Pref2≦P2 and Pref1≦P1 Here, Pref2 and Pref1 are preset reference values, and Pref1 <Pref2である。

[0052] The pressure changes when the internal pressure of air supply pipe 630 is increased using gas supply source 622 as follows: When second pressure P2, which is the internal pressure of air supply pipe 630, reaches first threshold value Pt1, opening condition A1 is met and valve 610 opens, gas flows from air supply pipe 630 to exhaust pipe 640, and first pressure P1 increases, while when second pressure P2 decreases and falls below second threshold value Pt2, closing condition A2 is met and valve 610 closes. If this operation is repeated, the warning stop condition D2 described above is eventually met and the warning sound stops.

[0053] The pressurization operation using gas supply source 622 described above is usually performed when the user is in an upright, unloaded state with no load applied to the user, as shown in Fig. 4. At this time, when the internal pressure of air supply pipe 630 and exhaust pipe 640 is increased using gas supply source 622, control unit 500 can be thought of as adjusting the opening and closing of valve 610 so that first pressure P1 is lower than second pressure P2. In this way, first pressure P1 is lower than second pressure P2, which has the advantage of reducing the assist force on the user's lower back when bending and reducing resistance during bending, making movement easier.

[0054] The relationship between various pressure values related to the opening and closing control of the valve 610 is preferably set as follows, for example. 0<ΔPt <Pref1<Pb<Pt2<Pref2<Pt1 (E1) Here, ΔPt is the differential threshold for the opening condition B1, Pref1 and Pref2 are the reference pressures for the warning stop condition D2, Pb is the lower limit pressure for the warning generation condition D1, Pt2 is the second threshold for the closing condition A2, and Pt1 is the first threshold for the opening condition A1, all of which are gauge pressures.

[0055] The control unit 500 may use only one of the first control and second control described above to control the opening and closing of the valve 610. The control unit 500 may also execute other opening and closing controls that are different from the first control and the second control. In either case, it is preferable that the control unit 500 switches the state of the valve 610 depending on at least one of the internal pressure of the first artificial muscle 430 and the internal pressure of the second artificial muscle 460.

[0056] 9 to 13 are explanatory diagrams showing a series of operations in the second embodiment, together with the above-mentioned FIG. 4. In this operation, it is assumed that, in the upright position shown in FIG. 4, the user first uses the gas supply source 622 to increase the internal pressure of the second artificial muscle 460 to the reference pressure Pr. At this time, in FIG. 4, the internal pressure of the second artificial muscle 460 is close to the reference pressure Pr, and the internal pressure of the first artificial muscle 430 is lower than the internal pressure of the second artificial muscle 460. Note that the total length of the first artificial muscle 430 and the connecting belt 470 is longer than the distance from the user's shoulder to the ankle, and the first artificial muscle 430 is in a relaxed state. In addition, the lower end connector 490 and the connecting belt 470 are pulled upward by the elastic belt 480.

[0057] 9 shows a bending motion in which the user bends forward to lift the object PB from the state shown in FIG. 4. In the state shown in FIG. 9, the first artificial muscle 430 is stretched in response to the user's bending forward, and its internal pressure increases. At this time, if the above-described opening condition B1 is met, the valve 610 is switched from closed to open. After that, if the internal pressure of the first artificial muscle 430 becomes equal to or lower than the internal pressure of the second artificial muscle 460, the closing condition B2 is met, and the valve 610 returns to closed.

[0058] FIG. 10 shows the extension motion when lifting the object PB from the state shown in FIG. 9 . Here, the user lifts the object PB with the wrist orthosis 450 engaged with the object engagement part EG of the object PB, and the second artificial muscle 460 is stretched by the weight of the object PB. As a result, the internal pressure of the second artificial muscle 460 becomes higher than in FIG. 9 , and the tension of the second artificial muscle 460 also becomes higher. This tension of the second artificial muscle 460 can assist the user's arm, allowing the user to easily lift the object PB. When the internal pressure of the second artificial muscle 460 increases and reaches the first threshold value Pt1, the opening condition A1 is met, the valve 610 changes from closed to open, and the gas in the second artificial muscle 460 is supplied to the first artificial muscle 430, making the internal pressures of both muscles approximately equal. In response to this, the internal pressure of the first artificial muscle 430 increases, causing the first artificial muscle 430 to contract, increasing its tension. The tension of the first artificial muscle 430 can assist the user's lower back, allowing the user to easily stretch the lower back. Furthermore, when the lifting of the object PB is completed and the user is in a nearly upright position, the tension of the first artificial muscle 430 decreases slightly, and the internal pressure also decreases slightly.

[0059] FIG. 11 shows a bending motion when lifting and lowering the object PB. When the user starts bending forward to lift and lower the object PB as shown in FIG. 11, the first artificial muscle 430 is stretched, increasing its tension and its internal pressure. Because the valve 610 is kept open, the internal pressure of the second artificial muscle 460 also increases in response to the increase in the internal pressure of the first artificial muscle 430, and its tension also increases. Therefore, the user can receive assistance from both the first artificial muscle 430 in the waist and the second artificial muscle 460 in the arms.

[0060] FIG. 12 shows the load release operation after the object PB is placed on the base BS. In this state, the wrist orthosis 450 is released from engagement with the object PB. When the object PB is released, the second artificial muscle 460 contracts in response, reducing its tension and rapidly reducing its internal pressure. When the internal pressure of the second artificial muscle 460 rapidly reduces to or below the second threshold Pt2, the closing condition A2 is met and the valve 610 closes. In the state shown in FIG. 12, assistance of the user's waist by the first artificial muscle 430 is maintained.

[0061] 13 shows the extension operation after the load is released. When the waist is extended after the object PB is released, the first artificial muscle 430 contracts, reducing the tension and its internal pressure. Furthermore, as the body approaches an upright position, the tension of the first artificial muscle 430 becomes almost zero, and the connecting belt 470 is pulled up by the tension of the elastic belt 480. This tension of the elastic belt 480 also functions as an assist force for the waist.

[0062] In the states of FIGS. 4, 9, 12, and 13 where there is no load from the object PB, the internal pressure of the second artificial muscle 460 is slightly low, and the assist force on the arm is also slightly low. On the other hand, in the states of FIGS. 10 and 11 where there is a load from the object PB, the internal pressure of the second artificial muscle 460 is higher than when there is no load, and the assist force on the arm is also high. Therefore, the assist device 400 can generate an assist force according to the presence or absence of a load. Furthermore, when there is no load, the tension of the first artificial muscle 430 and the second artificial muscle 460 is also slightly low, making it easier for the user to move. As such, it can be seen that the assist device 400 of this embodiment has excellent mobility and load responsiveness.

[0063] 14 is a graph showing an example of changes in the first pressure P1 and the second pressure P2 in response to the user's movements. The horizontal axis represents time, and the vertical axis represents pressure. The changes in the first pressure P1 are depicted with a dashed line, and the changes in the second pressure P2 are depicted with a solid line. Below the pressure P1 and P2 lines, the open / closed state of the valve 610 is depicted with a solid line.

[0064] The sections in FIG. 14 have the following correspondence with the states in FIGS. 4 and 9 to 13 described above. (1) Time t0 to t10: Upright state in Figure 4 (2) Time t10 to t20: Bending state of Figure 9 (3) Time t20 to t30: Lifting state of Figure 10 (4) Time t30 to t40: Holding state from the state of FIG. 10 to the state of FIG. 11 (5) Time t40 to t50: Lowering state of Figure 11 (6) Time t50 to t60: From the load-released state in Figure 12 to the extension state in Figure 13 (7) After time t60: Upright state in Figure 4

[0065] At time t11, between time t10 and time t20, as the user bends forward as shown in Fig. 9, the internal pressure of the first artificial muscle 430 increases, opening condition B1 is met, and the valve 610 opens. Thereafter, at time t12, closing condition B2 is met, and the valve 610 closes. Also, at time t21, between time t20 and time t30, as shown in Fig. 10, the second artificial muscle 460 is stretched by the weight of the object PB, increasing the internal pressure of the second artificial muscle 460, opening condition A1 is met, and the valve 610 opens. Thereafter, the valve 610 remains open while the object PB is being carried, but at time t51, between time t50 and time t60, as the object PB is released, closing condition A2 is met, and the valve 610 closes, as shown in Fig. 12.

[0066] As described above, in the second embodiment, as in the first embodiment, the valve 610 switches the connecting flow path between the first artificial muscle 430 and the second artificial muscle 460 between a connected state and a disconnected state, allowing gas to be exchanged between the first artificial muscle 430 and the second artificial muscle 460, thereby reducing gas consumption. Also, both assist by the first artificial muscle 430 and assist by the second artificial muscle 460 can be achieved.

[0067] Furthermore, in the second embodiment, the control unit 500 controls the open / close state of the valve 610 using the first control and second control described above. As a result, it is possible to simultaneously assist the waist and the arms while exchanging gas between the first artificial muscle 430 and the second artificial muscle 460 according to the internal pressure of the first artificial muscle 430 and the internal pressure of the second artificial muscle 460. Furthermore, in the second embodiment, the internal pressure of the second artificial muscle 460 when lifting a load changes depending on the load weight, and this can be used to generate an assist force (artificial muscle internal pressure) according to the load weight. Furthermore, the assist device of the second embodiment has a function to determine whether or not a load is applied according to the internal pressure of the artificial muscle. Therefore, when operating without a load, the waist assist force is small, improving ease of movement and mobility.

[0068] The present disclosure is not limited to the above-described embodiments, embodiments, and variations, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, embodiments, and variations corresponding to the technical features in each aspect described in the Summary of the Disclosure section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0069] First Embodiment 100... Assist device, 110... Shoulder orthosis, 120... Lower limb orthosis, 130... First artificial muscle, 132... Manifold, 134... Muscle member, 140... Pressure regulating device, 150... Wrist orthosis, 160... Second artificial muscle, 200... Control unit, 300... Intake and exhaust system, 310... Valve, 320... Gas source connecting pipe, 322... Gas supply source, 324... Regulator, 330... Exhaust pipe, 332... Speed controller, 334... Relief valve, 336... Buffer tank, 340... Air intake pipe, 342... Pressure sensor, 350... Branched exhaust pipe, 352... First check valve, 360... Auxiliary connecting pipe, 362... Second check valve, 370... Branched pipe Second Embodiment 400... Assist device, 410... Shoulder orthosis, 420... Lower limb orthosis, 421... First orthosis, 422... Second orthosis, 430... First artificial muscle, 440... Pressure adjustment device, 450... Wrist orthosis, 460... Second artificial muscle, 470... Connecting belt, 480... Elastic belt, 490... Lower end connecting device, 492... Connecting device main body, 494... Pin, 495... Buttocks pad, 500... Control unit, 600... Intake and exhaust system, 610... Valve, 620... Gas supply path, 622... Gas supply source, 624... Check valve, 630... Air intake pipe, 632... Second pressure sensor, 640... Exhaust pipe, 642... First pressure sensor, 650... Branch pipe

Claims

1. An assist device that assists a user's movement, a first artificial muscle that is attached between two parts of the user and shortens when internal pressure increases and extends when the internal pressure decreases; a second artificial muscle attached between two parts different from the first artificial muscle; a pressure adjusting device that adjusts the internal pressure of the first artificial muscle and the second artificial muscle; Equipped with The pressure adjusting device is A connection flow path connecting the first artificial muscle and the second artificial muscle; a valve provided in the connection flow path and capable of switching the connection flow path between a communication state and a non-communication state; a control unit that switches the state of the valve in accordance with at least one of the internal pressure of the first artificial muscle and the internal pressure of the second artificial muscle; Equipped with The control unit an operation of switching the state of the valve to the communicating state in response to an increase in the internal pressure of the first artificial muscle, and accumulating exhaust gas from the first artificial muscle as auxiliary gas in the second artificial muscle; an operation of switching the state of the valve to the communicating state in response to a decrease in internal pressure of the first artificial muscle or an increase in internal pressure of the second artificial muscle, and supplying the auxiliary gas accumulated in the second artificial muscle to the first artificial muscle; The assist device is configured to perform the above.

2. The assist device according to claim 1, the pressure adjustment device includes a gas supply source that supplies gas to the first artificial muscle, the valve is connected between the gas supply source and the first artificial muscle, and is configured to be switchable between any of a plurality of states including an air supply state in which the gas is supplied to the first artificial muscle, and an exhaust state in which the gas is exhausted from the first artificial muscle; The connecting flow path is an air supply pipe connecting the valve and the first artificial muscle; an exhaust pipe that connects the valve and the second artificial muscle and accumulates exhaust gas that reaches the valve from the first artificial muscle as the auxiliary gas in the second artificial muscle when the internal pressure of the first artificial muscle increases; Including, The pressure adjusting device further comprises: an auxiliary connecting pipe that connects the second artificial muscle and the air supply pipe and supplies the auxiliary gas from the second artificial muscle to the first artificial muscle via the air supply pipe when the internal pressure of the first artificial muscle decreases or when the internal pressure of the second artificial muscle increases; An assist device comprising:

3. The assist device according to claim 2, the exhaust pipe has a first check valve provided so that gas flows unidirectionally from the valve toward the second artificial muscle, The auxiliary connecting pipe has a second check valve provided so that gas flows unidirectionally from the second artificial muscle toward the air supply pipe. Assist device.

4. The assist device according to any one of claims 1 to 3, the first artificial muscle is configured to be attached between the shoulders and lower limbs of the user via the back of the user to assist the lower back of the user, The assist device is configured such that the second artificial muscle is attached between the shoulder and the wrist of the user to assist the arm of the user.

5. The assist device according to claim 4, further comprising: a shoulder orthosis that is attached to the shoulder of the user and to which an upper end of the first artificial muscle is connected; a lower end connector to which the lower end of the first artificial muscle is connected at a height position corresponding to a part below the waist of the user; a lower limb orthosis attached to the lower limb of the user below the lower end connector; a connecting belt that connects the lower end connector and the lower limb orthosis; An assist device comprising:

6. The assist device according to claim 5, further comprising: an elastic belt that applies tension between the shoulder orthosis and the lower end connector by connecting the shoulder orthosis and the lower end connector; The assist device, wherein the lower end connector is not fixed to the user, but is positioned by the elastic belt and the connecting belt.

7. The assist device according to any one of claims 4 to 6, further comprising: a first pressure sensor that detects a first pressure corresponding to the internal pressure of the first artificial muscle; a second pressure sensor that detects a second pressure corresponding to the internal pressure of the second artificial muscle; Equipped with The control unit (i) a first control that opens the valve when the second pressure becomes equal to or greater than a first threshold value, thereby bringing the connecting flow path into the connected state, and closes the valve when the second pressure becomes equal to or less than a second threshold value that is smaller than the first threshold value, thereby bringing the connecting flow path into the disconnected state; (ii) a second control that opens the valve to bring the connecting flow path into the connected state when a difference obtained by subtracting the second pressure from the first pressure becomes larger than a difference threshold, and closes the valve to bring the connecting flow path into the disconnected state when the first pressure becomes equal to or lower than the second pressure; The assist device is configured to perform the above.

8. The assist device according to claim 7, the control unit is configured to issue a warning when the second pressure becomes equal to or lower than a lower limit value that is lower than the second threshold value, The assist device further includes a gas supply source that increases the internal pressure of the connecting flow path.

9. 9. The assist device according to claim 8, The control unit adjusts opening and closing of the valve so that the first pressure is lower than the second pressure when the internal pressure of the connection flow path is increased using the gas supply source.

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