Artificial muscle device

Abstract

To provide a technology that can operate an artificial muscle without using a compressor.SOLUTION: An artificial muscle device includes: a hermetically sealed bag while accommodating a grease including a base oil and a thickening agent; a braided sleeve that covers an outer peripheral surface of the bag; and an electromagnet disposed in at least one of the inside and outside of the braided sleeve.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to artificial muscle devices. [Background technology]

[0002] Conventionally, artificial muscles equipped with a fluid pressure actuator are known (Patent Document 1). This fluid pressure actuator includes a tube and a sleeve that covers the outer surface of the tube. The tube contains a fluid and expands and contracts due to fluid pressure. The sleeve is a cylindrical structure made of woven cords oriented in a predetermined direction, and follows and regulates the expansion and contraction of the tube. With this technology, the fluid pressure actuator is operated by at least one of the hydraulic pressure generated when a liquid as a fluid flows in and out of the tube, and the air pressure generated when air as a fluid flows in and out of the tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-76167 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional technology requires a compressor to generate hydraulic or pneumatic pressure. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to a first aspect of the present disclosure, an artificial muscle device is provided. The artificial muscle device includes a sealed bag containing grease containing a base oil and a thickener, a braided sleeve covering the outer surface of the bag, and an electromagnet located inside or outside the braided sleeve. According to this aspect, the artificial muscle device can be operated as an artificial muscle using magnetic force without using a compressor. (2) In the above embodiment, the electromagnets may include a first electromagnet and a second electromagnet, the grease is non-magnetic, the first electromagnet and the second electromagnet are arranged to face each other along a predetermined first direction, and the bag is arranged between the first electromagnet and the second electromagnet. When the first electromagnet and the second electromagnet are energized, the first electromagnet and the second electromagnet attract each other along the first direction, causing the bag to expand along a second direction perpendicular to the first direction while contracting along the first direction. When the first electromagnet and the second electromagnet are deenergized, the attractive force acting between the first electromagnet and the second electromagnet disappears, causing the bag to relax along the first direction. According to this embodiment, the artificial muscle device can physically compress or relax the bag by moving the first electromagnet and the second electromagnet using magnetic force. As a result, the artificial muscle device can operate as an artificial muscle by causing the grease contained in the bag to flow and deforming the bag and the braided sleeve. (3) The above-described embodiment may further include a magnetic body, the grease being non-magnetic, the electromagnet and the magnetic body being arranged to face each other along a predetermined third direction, the bag being arranged between the electromagnet and the magnetic body, and when the electromagnet is energized, the electromagnet attracts the magnetic body along the third direction, causing the bag to expand along a fourth direction perpendicular to the third direction while contracting along the third direction. When the electromagnet is deenergized, the attractive force of the electromagnet on the magnetic body disappears, causing the bag to relax along the third direction. According to this embodiment, the artificial muscle device can physically compress or relax the bag by using magnetic force to attract the magnetic body to the electromagnet. This allows the artificial muscle device to function as an artificial muscle by causing the grease contained in the bag to flow and deforming the bag and the braided sleeve. (4) In the above embodiment, the electromagnets may include a first electromagnet and a second electromagnet, the grease is magnetic, the first electromagnet and the second electromagnet are arranged outside the braided sleeve to face each other along a predetermined fifth direction, the bag is arranged between the first electromagnet and the second electromagnet, when current is applied to the first electromagnet and the second electromagnet, the grease is attracted to the first electromagnet and the second electromagnet, and the bag expands along the fifth direction while contracting in a sixth direction perpendicular to the fifth direction, and when current is stopped, the attractive force of the first electromagnet and the second electromagnet to the grease disappears, and the bag relaxes along the sixth direction. According to this embodiment, the artificial muscle device can attract the grease to the electromagnets by magnetic force generated by applying current to a pair of electromagnets arranged opposite each other to sandwich the bag. This allows the artificial muscle device to function as an artificial muscle by causing the grease contained in the bag to flow and deforming the bag and the braided sleeve. (5) In the above embodiment, the grease may be magnetic, and the electromagnet may be disposed outside the braided sleeve in a circumferential direction centered on a predetermined seventh direction so as to surround the bag. When the electromagnet is energized, the grease is attracted to the electromagnet, causing the bag to expand in an eighth direction perpendicular to the seventh direction while contracting in the seventh direction. When the electromagnet is de-energized, the attractive force of the electromagnet attracting the grease disappears, causing the bag to relax along the seventh direction. According to this embodiment, the artificial muscle device can attract the grease to the electromagnet by magnetic force generated by energizing a single electromagnet disposed to surround the bag. This allows the artificial muscle device to operate as an artificial muscle by causing the grease contained in the bag to flow and deforming the bag and the braided sleeve. The present disclosure can be realized in various forms other than the above-described artificial muscle device, such as a method for manufacturing an artificial muscle device, a method for controlling an artificial muscle device, a computer program for implementing the control method, or a non-transitory recording medium on which the computer program is recorded. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 shows the configuration of an artificial muscle device according to a first embodiment. [Figure 2] FIG. 2 shows the configuration of the artificial muscle device in the first embodiment. [Figure 3] FIG. 10 is a diagram showing the configuration of an artificial muscle device according to a second embodiment. [Figure 4] FIG. 1 shows the configuration of an artificial muscle device according to a third embodiment. [Figure 5] FIG. 2 shows the configuration of the artificial muscle device according to the third embodiment. [Figure 6] FIG. 10 is a diagram showing the configuration of an artificial muscle device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: FIG. 1 is a first diagram showing the configuration of an artificial muscle device 1 in the first embodiment. FIG. 2 is a second diagram showing the configuration of the artificial muscle device 1 in the first embodiment. The artificial muscle device 1 includes a bag 110, a braided sleeve 120, a first electromagnet 131, and a second electromagnet 132. The artificial muscle device 1 further includes a first fixing member 141, a second fixing member 142, a first shaft portion 151, and a second shaft portion 152. FIG. 1 shows the configuration of the artificial muscle device 1 in a non-energized state where no current is applied to the electromagnets 131 and 132. FIG. 2 shows the configuration of the artificial muscle device 1 in a powered state where current is applied to the electromagnets 131 and 132.

[0009] The bag 110 is sealed while containing the grease 61. The bag 110 deforms in accordance with the flow of the grease 61. The bag 110 may or may not have elasticity. In this embodiment, the bag 110 is not fixed, but is disposed between the first electromagnet 131 and the second electromagnet 132 inside the braided sleeve 120. In other embodiments, the bag 110 may be fixed to any member such as the shaft portions 151, 152.

[0010] The grease 61 is a viscous fluid composition defined in the Japanese Industrial Standards (JIS K 2220). In this embodiment, the grease 61 does not contain magnetic powder but contains a base oil and a thickener. In other words, the grease 61 of this embodiment is not magnetic. The grease 61 may contain other components such as an antioxidant.

[0011] The braided sleeve 120 covers the outer surface of the bag 110. The braided sleeve 120 is a structure in which cords oriented in a predetermined direction are braided. In the braided sleeve 120, a pantograph-like link mechanism formed by the crossing of the oriented cords is repeatedly arranged. The braided sleeve 120 can be made of a material used in conventional McKibben-type artificial muscles. For example, the NFL-30 manufactured by Denka Electron Co., Ltd. can be used as the braided sleeve 120. One end 121 of the braided sleeve 120 is fixed to a first shaft portion 151 extending along a predetermined first direction D1 using a first fixing member 141. The other end 122 of the braided sleeve 120 is fixed to a second shaft portion 152 extending along the first direction D1 using a second fixing member 142. The braided sleeve 120 has a cylindrical shape extending along the first direction D1. The braided sleeve 120 follows the expansion and contraction of the bladder 110 in a regulated manner.

[0012] The first electromagnet 131 and the second electromagnet 132 are each connected to a power supply device 90. The first electromagnet 131 and the second electromagnet 132 are arranged inside the braided sleeve 120 so as to face each other along the first direction D1. In other words, inside the braided sleeve 120, the pair of electromagnets 131, 132 are arranged so as to sandwich the bag 110 along the first direction D1. The first electromagnet 131 is fixed to a tip end 151a of the first shaft portion 151. The second electromagnet 132 is fixed to a tip end 152a of the second shaft portion 152. Note that the base end 151b of the first shaft portion 151 and the base end 152b of the second shaft portion 152 may each be a free end or a fixed end.

[0013] As shown in FIG. 2, when the first electromagnet 131 and the second electromagnet 132 are energized, the first electromagnet 131 and the second electromagnet 132 attract each other. As a result, the first electromagnet 131 and the second electromagnet 132 physically press against the bag 110 from both ends along the first direction D1. As the grease 61 flows due to the pressure, the pressed bag 110 expands along a second direction D2 perpendicular to the first direction D1 while contracting along the first direction D1. This causes the shape of each link mechanism of the braided sleeve 120 to deform from its initial state. In this way, the artificial muscle device 1 operates as an artificial muscle by converting the expansion of the bag 110 in the second direction D2 into output along the first direction D1 due to the tension generated by the deformation of the bag 110 and the braided sleeve 120.

[0014] As shown in FIG. 1, when the power supply to the first electromagnet 131 and the second electromagnet 132 is stopped, the attractive force acting between the first electromagnet 131 and the second electromagnet 132 disappears. This releases the pressure on the bag 110 from the first electromagnet 131 and the second electromagnet 132. With the pressure released, the bag 110 relaxes along the first direction D1 as the grease 61 flows. This causes the shape of each link mechanism of the braided sleeve 120 to return to its initial state. In this way, the artificial muscle device 1 operates as an artificial muscle by converting the relaxation of the bag 110 in the first direction D1 due to the loss of tension that occurred in the power-on state shown in FIG. 2 into an output along the first direction D1.

[0015] According to the first embodiment, the artificial muscle device 1 can physically press the bag 110 by using magnetic force to move the first electromagnet 131 and the second electromagnet 132. This allows the artificial muscle device 1 to operate as an artificial muscle by causing the grease 61 contained in the bag 110 to flow and deforming the bag 110 and the braided sleeve 120. With this configuration, a compressor is not required, and the artificial muscle device 1 can be made smaller.

[0016] Furthermore, according to the first embodiment, the bag 110 does not have an opening and is sealed while containing the grease 61. Therefore, compared to when the artificial muscle device 1 is operated by causing a fluid to flow in and out of the tube through an opening using hydraulic or air pressure, the possibility that the grease 61 as a fluid will leak out of the bag 110 and cause the artificial muscle device 1 to stop working can be reduced.

[0017] Furthermore, according to the first embodiment, the grease 61 may contain any component such as an antioxidant in addition to the base oil and the thickener, which can prevent the grease 61 from deteriorating.

[0018] It should be noted that first electromagnet 131 and second electromagnet 132 may be disposed outside braided sleeve 120, respectively.

[0019] B. Second embodiment: FIG. 3 is a diagram showing the configuration of an artificial muscle device 1a in a second embodiment. FIG. 3 shows the configuration of the artificial muscle device 1a in a non-energized state. In this embodiment, the configuration of the member that physically presses the bag 110 using magnetic force is different from that of the first embodiment. The other configurations are the same as those of the first embodiment unless otherwise specified. The same components as those of the first embodiment are given the same reference numerals and will not be described.

[0020] The artificial muscle device 1a includes a sealed bag 110 containing nonmagnetic grease 61, a braided sleeve 120 covering the outer surface of the bag 110, an electromagnet 131, and a magnetic body 135. The magnetic body 135 is an object that is attracted to the electromagnet 131 when current is applied to the electromagnet 131. The bag 110 is disposed between the electromagnet 131 and the magnetic body 135. The electromagnet 131 and the magnetic body 135 are disposed so as to face each other along the third direction D3. The first shaft 151 and the second shaft 152 each extend along the third direction D3. The braided sleeve 120 has a cylindrical shape that extends along the third direction D3. In other words, the artificial muscle device 1a has a configuration in which either the first electromagnet 131 or the second electromagnet 132 shown in FIGS. 1 and 2 is replaced with the magnetic body 135.

[0021] 3, when the electromagnet 131 is energized, the electromagnet 131 attracts the magnetic material 135 along the third direction D3, causing the bag 110 to expand along the fourth direction D4 that is perpendicular to the third direction D3 and contract along the third direction D3. When the energization of the electromagnet 131 is stopped, the attractive force with which the electromagnet 131 attracts the magnetic material 135 disappears, causing the bag 110 to relax along the third direction D3.

[0022] According to the second embodiment, the magnetic force is used to attract the magnetic body 135 to the electromagnet 131, thereby physically compressing or relaxing the bag 110. This allows the artificial muscle device 1a to operate as an artificial muscle by causing the grease 61 contained in the bag 110 to flow and deforming the bag 110 and the braided sleeve 120.

[0023] Alternatively, electromagnet 131 and magnetic body 135 may be disposed outside braided sleeve 120 .

[0024] C. Third embodiment: FIG. 4 is a first diagram showing the configuration of an artificial muscle device 1b in a third embodiment. FIG. 4 illustrates the configuration of the artificial muscle device 1b in a non-energized state. FIG. 5 is a second diagram showing the configuration of the artificial muscle device 1b in a third embodiment. FIG. 5 illustrates the configuration of the artificial muscle device 1b in a power-on state. This embodiment differs from the first embodiment in the arrangement of the first electromagnet 131 and the second electromagnet 132 and the composition of the grease 62. Unless otherwise specified, the other configurations are the same as those in the first embodiment. The same reference numerals are used for the same configurations as those in the first embodiment, and descriptions thereof will be omitted.

[0025] In this embodiment, the grease 62 includes magnetic powder in addition to a base oil and a thickener. That is, the grease 62 of this embodiment is magnetic. For example, the magnetorheological fluid composition described in Japanese Patent No. 5587734 can be used as the grease 62. Specifically, the grease 62 includes, for example, a mineral oil as the base oil, at least one of a urea-based thickener and a soap-based thickener as the thickener, and magnetic metal powder as the magnetic powder. More specifically, the grease 62 includes, for example, a mixed mineral oil of naphthenic mineral oil and paraffinic mineral oil as the base oil, lithium soap as the thickener, and iron powder as the magnetic powder. The base oil may be a synthetic oil or a mixture of mineral oil and synthetic oil. The grease 62 may also include other components, such as a surfactant for dispersing the magnetic powder in the base oil and thickener.

[0026] In this embodiment, the first shaft portion 151 and the second shaft portion 152 each extend along a sixth direction D6 that is perpendicular to the fifth direction D5. The braided sleeve 120 has a cylindrical shape that extends along the sixth direction D6. The first electromagnet 131 and the second electromagnet 132 are arranged outside the braided sleeve 120 to face each other along the fifth direction D5. In other words, the pair of electromagnets 131, 132 are arranged to sandwich the bag 110 along the fifth direction D5.

[0027] As shown in Figure 5, when the first electromagnet 131 and the second electromagnet 132 are energized, the grease 62 is attracted to the first electromagnet 131 and the second electromagnet 132. As the magnetic force causes the grease 62 to flow, the bag 110 expands in the fifth direction D5 while contracting in the sixth direction D6. This causes the shape of each link mechanism of the braided sleeve 120 to deform from its initial state. In this way, the artificial muscle device 1b operates as an artificial muscle by converting the expansion of the bag 110 in the fifth direction D5 into output in the sixth direction D6 due to the tension generated by the deformation of the bag 110 and the braided sleeve 120.

[0028] As shown in Figure 4, when the power supply to the first electromagnet 131 and the second electromagnet 132 is stopped, the attractive force that attracts the grease 62 between the first electromagnet 131 and the second electromagnet 132 disappears. This causes the grease 62 to flow, and the bag 110 relaxes along the sixth direction D6, returning the shape of each link mechanism of the braided sleeve 120 to its initial state. In this way, the artificial muscle device 1b operates as an artificial muscle by using the relaxation of the bag 110 in the sixth direction D6 due to the loss of tension that occurred in the power-on state shown in Figure 5 as an output along the sixth direction D6.

[0029] According to the third embodiment, the artificial muscle device 1b can attract the grease 62 to the electromagnets 131, 132 by magnetic force generated by energizing the electromagnets 131, 132. This allows the artificial muscle device 1b to flow the grease 62 contained in the bag 110, deforming the bag 110 and the braided sleeve 120, thereby operating as an artificial muscle.

[0030] Furthermore, according to the third embodiment, the artificial muscle device 1b uses grease 62 in which magnetic powder is added to a base oil and a thickener. This reduces the possibility of the magnetic powder in the solution separating compared to using a magnetic fluid in which magnetic powder is mixed with a base oil without a thickener. Furthermore, because the viscosity of the grease 62 is higher than that of the magnetic fluid, even if a hole is formed in the bag 110 due to damage to the bag 110, the possibility of the fluid contained in the bag 110 leaking can be reduced. Furthermore, because the viscosity of the grease 62 is higher than that of the magnetic fluid, when the bag 110 is deformed, the shape after deformation can be more easily maintained.

[0031] D. Fourth embodiment: FIG. 6 is a diagram showing the configuration of an artificial muscle device 1c in a fourth embodiment. FIG. 6 shows the configuration of the artificial muscle device 1c in a non-energized state. In this embodiment, the number and shape of the electromagnets 133 are different from those in the third embodiment. The other configurations are the same as those in the third embodiment unless otherwise specified. The same reference numerals are used for the same configurations as those in the third embodiment, and descriptions thereof will be omitted.

[0032] The artificial muscle device 1c includes a sealed bag 110 containing magnetic grease 62, a braided sleeve 120 covering the outer surface of the bag 110, and one electromagnet 133. The electromagnet 133 in this embodiment has a cylindrical shape extending along a predetermined seventh direction D7. The electromagnet 131 is disposed outside the braided sleeve 120 in the circumferential direction centered on the seventh direction D7 so as to surround the bag 110.

[0033] When the electromagnet 133 is energized, the grease 62 is attracted to the electromagnet 133, causing the bag 110 to expand along an eighth direction D8 perpendicular to the seventh direction D7 while contracting in the seventh direction D7. When the electromagnet 133 is deenergized, the attractive force of the electromagnet 133 attracting the grease 62 disappears, causing the bag 110 to relax along the seventh direction D7.

[0034] According to the fourth embodiment, even when one electromagnet 133 is used that is arranged to surround the bag 110, the grease 62 can be attracted by the magnetic force generated by energizing the electromagnets 131 and 132. This allows the artificial muscle device 1c to operate as an artificial muscle by causing the grease 62 contained in the bag 110 to flow and deforming the bag 110 and the braided sleeve 120.

[0035] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention 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 appropriately deleted. [Explanation of symbols]

[0036] 1, 1a to 1c...artificial muscle device, 61, 62...grease, 90...power supply unit, 110...bag, 120...braided sleeve, 121...one end of braided sleeve, 122...other end of braided sleeve, 131, 132, 133...electromagnet, 135...magnetic body, 141...first fixing member, 142...second fixing member, 151...first shaft portion, 151a...tip portion of first shaft portion, 151b...base end portion of first shaft portion, 152...second shaft portion, 152a...tip portion of second shaft portion, 152b...base end portion of second shaft portion, D1...first direction, D2...second direction, D3...third direction, D4...fourth direction, D5...fifth direction, D6...sixth direction, D7...seventh direction, D8...eighth direction

Claims

1. An artificial muscle device, a sealed bag containing grease containing a base oil and a thickener; a braided sleeve covering the outer circumferential surface of the bag; an electromagnet disposed inside or outside the braided sleeve.

2. The artificial muscle device according to claim 1, the electromagnets include a first electromagnet and a second electromagnet; The grease is non-magnetic, the first electromagnet and the second electromagnet are arranged to face each other along a predetermined first direction, the bag is disposed between the first electromagnet and the second electromagnet; when the first electromagnet and the second electromagnet are energized, the first electromagnet and the second electromagnet attract each other along the first direction, causing the bag to expand along a second direction perpendicular to the first direction and contract along the first direction, When the power supply to the first electromagnet and the second electromagnet is stopped, the attractive force acting between the first electromagnet and the second electromagnet disappears, causing the bag to relax along the first direction.

3. The artificial muscle device according to claim 1, further comprising: It has a magnetic body, The grease is non-magnetic, the electromagnet and the magnetic body are arranged to face each other along a predetermined third direction, the bag is disposed between the electromagnet and the magnetic body; When the electromagnet is energized, the electromagnet attracts the magnetic body along the third direction, causing the bag to expand along a fourth direction perpendicular to the third direction and contract along the third direction, When the electromagnet is de-energized, the attractive force of the electromagnet to the magnetic body disappears, causing the bag to relax along the third direction.

4. The artificial muscle device according to claim 1, the electromagnets include a first electromagnet and a second electromagnet; The grease is magnetic, the first electromagnet and the second electromagnet are disposed on the outside of the braided sleeve so as to face each other along a predetermined fifth direction; the bag is disposed between the first electromagnet and the second electromagnet; when the first electromagnet and the second electromagnet are energized, the grease is attracted to the first electromagnet and the second electromagnet, causing the bag to expand along the fifth direction and contract in a sixth direction perpendicular to the fifth direction; When the power supply to the first electromagnet and the second electromagnet is stopped, the attractive force with which the first electromagnet and the second electromagnet attract the grease disappears, causing the bag to relax along the sixth direction.

5. The artificial muscle device according to claim 1, The grease is magnetic, the electromagnet is disposed on the outside of the braided sleeve in a circumferential direction around a predetermined seventh direction so as to surround the bag, When the electromagnet is energized, the grease is attracted to the electromagnet, causing the bag to expand along an eighth direction perpendicular to the seventh direction while contracting in the seventh direction; When the electromagnet is de-energized, the attractive force of the electromagnet on the grease disappears, causing the bag to relax along the seventh direction.

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