Operational support device

Abstract

To provide an action assistance device for enabling a stable walking action.SOLUTION: A hydraulic prosthetic foot 1 includes: a lower leg member 3 to which a support member 2 attached to a thigh part of a user is rotatably connected and also to which a foot member 4 to be grounded on the ground is rotatably connected; a first hydraulic cylinder 7 for rotating the foot member 4; and a second hydraulic cylinder 8 to be extended / contracted when the foot member 4 is rotated with respect to the lower leg member 3. The first hydraulic cylinder 7 includes a first cylinder chamber 71 formed inside the lower leg member 3. The second hydraulic cylinder 8 includes a second cylinder chamber 81 formed inside the lower leg member 3. Communication channels 55, 56 for communication between the first cylinder chamber 71 and the second cylinder chamber 81 is formed inside the lower leg member 3.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an operation assistance device.

Background Art

[0002] Patent Document 1 discloses a walking assistance device including a support member attached to the thigh of a user, a lower leg member rotatably connected to the support member in the bending and extending directions, a foot member rotatably connected to the lower leg member in the plantar flexion and dorsiflexion directions, a first hydraulic cylinder provided between the support member and the lower leg member and contracting when the lower leg member rotates in the bending direction with respect to the support member, a second hydraulic cylinder provided between the lower leg member and the foot member and contracting when the foot member rotates in the dorsiflexion direction with respect to the lower leg member, a first communication passage communicating a one-side pressure chamber that discharges liquid when the first hydraulic cylinder contracts and a one-side pressure chamber that discharges liquid when the second hydraulic cylinder contracts. In the walking assistance device described in Patent Document 1, a part of the first hydraulic cylinder and the second hydraulic cylinder is provided so as to be exposed from the lower leg member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a walking assistance device like the one described in Patent Document 1, the inclination of the first and second hydraulic cylinders relative to the lower leg member changes as they extend and retract during the operation of the walking assistance device. In other words, the relative position of the first and second hydraulic cylinders changes during the operation of the walking assistance device. Therefore, the first and second hydraulic cylinders need to be connected by a flexible pipe, such as a hose. Since this pipe is exposed to the outside of the lower leg member, it may get caught on the pipe during walking, potentially affecting the walking motion.

[0005] This invention has been made in view of the above-mentioned problems, and aims to provide a movement assistance device that enables stable walking motion. [Means for solving the problem]

[0006] The present invention relates to an assistive device for movement, comprising: a lower leg member to which a support member attached to the user's thigh is rotatably connected and to which a foot member that touches the ground is rotatably connected; a first hydraulic cylinder that expands and contracts when the support member rotates relative to the lower leg member; and a second hydraulic cylinder that rotates the foot member, wherein the first hydraulic cylinder has a first cylinder chamber formed within the lower leg member, and the second hydraulic cylinder has a second cylinder chamber formed within the lower leg member, and a communication passage is formed within the lower leg member that connects the first cylinder chamber and the second cylinder chamber.

[0007] In this invention, the first hydraulic cylinder and the second hydraulic cylinder operate in conjunction. Furthermore, the first cylinder chamber and the second cylinder chamber are formed within the lower leg member, and a connecting passage is formed within the lower leg member between the first and second cylinder chambers. As a result, there are no external pipes exposed from the lower leg member, preventing the user from tripping over pipes while walking.

[0008] Furthermore, the present invention further comprises: a first hydraulic cylinder having a first piston slidably inserted into a first cylinder chamber, a first link rotatably connected to the first piston and a support member, and a first pressure chamber partitioned within the first cylinder chamber by the first piston, from which liquid is discharged when the first hydraulic cylinder contracts; and a second hydraulic cylinder having a second piston slidably inserted into a second cylinder chamber, a second link rotatably connected to the second piston and a foot member, and a second pressure chamber partitioned within the second cylinder chamber by the second piston, from which liquid is discharged when the second hydraulic cylinder contracts; and a connecting passage connecting the first pressure chamber and the second pressure chamber.

[0009] In this invention, a first link is rotatably connected to a first piston and a support member, and a second link is rotatably connected to a second piston and a foot member. Therefore, when the support member rotates relative to the lower leg member, the first piston slides within the first cylinder chamber, and consequently the second piston slides within the second cylinder chamber, causing the foot member to rotate. This enables walking motion in an assistive device in which a first cylinder chamber and a second cylinder chamber are formed within the lower leg member.

[0010] Furthermore, in this invention, a tank is formed within the lower leg member, which is a space for storing the liquid supplied to and discharged from the first cylinder chamber and the second cylinder chamber, and the tank is It is a place that is always covered by liquid, even if the liquid level inside the tank fluctuates. It is characterized by being connected to a passage at the bottom.

[0011] In this invention, a tank, which is a space within the lower leg member, is provided so that the tank is not exposed to the outside of the lower leg member. As a result, there is no external piping connecting the tank and the connecting passage, preventing the user from tripping over the piping while walking. Furthermore, since the tank communicates with the connecting passage at its lower bottom, it is prevented from mixing gas with the liquid supplied to the first cylinder chamber and the second cylinder chamber.

[0012] Furthermore, the present invention further comprises a switching valve provided in the communication passage for switching the flow of liquid between the communication passage and the tank, wherein the switching valve has a shut-off position that blocks the flow of liquid from the communication passage toward the tank and a communication position that allows the flow of liquid from the communication passage toward the tank, the communication position consists of a plurality of throttling positions in which the amount of liquid throttling differs from one another, and the switching valve is provided with a valve body in which a plurality of throttling portions corresponding to the plurality of throttling positions are formed in a continuous manner in the axial direction.

[0013] In this invention, when the switching valve is switched to the shut-off position, the flow of liquid from the communication passage to the tank is shut off. Therefore, when the support member rotates in the bending direction relative to the lower leg member, the foot member rotates significantly in the plantarflexion direction relative to the lower leg member in conjunction with it, and when the support member rotates in the extension direction relative to the lower leg member, the foot member rotates significantly in the dorsiflexion direction relative to the lower leg member in conjunction with it. On the other hand, when the switching valve is switched to the communication position, the communication passage and the tank are connected. Therefore, even if the support member rotates relative to the lower leg member, the amount of rotation of the foot member relative to the lower leg member in conjunction with it can be reduced. In this way, by switching the switching valve between the shut-off position and the communication position, the user can perform a natural walking motion. Furthermore, the communication position consists of multiple throttling positions in which the amount of liquid throttling differs from one another, and the switching valve is provided with a valve body in which multiple throttling sections corresponding to the multiple throttling positions are formed continuously in the axial direction. Therefore, the ease of rotation of the support member when it rotates relative to the lower leg member can be adjusted by the multiple throttling positions. In other words, multiple constriction positions allow for adjustment of the cushioning effect and the coordination of the foot member when the support member rotates in the bending direction. This allows the user to change the constriction position depending on whether they are walking on flat ground or going up and down stairs, thereby enabling appropriate foot movement in each situation and appropriately reducing the impact on the user.

[0014] Furthermore, the present invention further includes an operating unit that can be operated from the outside, and the throttle position of the switching valve is selected by operating the operating unit.

[0015] In this invention, the throttle position of the switching valve can be easily selected by operating the control unit from the outside.

[0016] Furthermore, the present invention is characterized in that the volume of the second hydraulic cylinder is larger than the volume of the first hydraulic cylinder.

[0017] In this invention, the first hydraulic cylinder is more flexible than the second hydraulic cylinder. During a user's walking motion, the support member rotates more than the foot member; therefore, this configuration allows the support member to rotate more easily, enabling the user to walk more naturally.

[0018] Furthermore, the present invention is characterized in that the lower leg member comprises a first member connected to a support member and having a first cylinder chamber formed thereon, a second member connected to a foot member and having a second cylinder chamber formed thereon, and a length adjustment member provided between the first member and the second member and having a connecting passage formed thereon, which allows the length of the lower leg member to be adjusted.

[0019] In this invention, the length adjustment member is provided only with a connecting passage and no other cylinder chambers or the like, so the length in the vertical direction can be easily adjusted. This makes it possible to match the length of the user's left and right legs.

[0020] Furthermore, the present invention provides a communication passage comprising a first communication passage equipped with a switching valve and a second communication passage equipped with a check valve that allows only the flow of liquid from the tank to the communication passage, and the tank is It is a place that is always covered by liquid, even if the liquid level inside the tank fluctuates. The bottom is characterized by being connected to a first communication passage via a switching valve and to a second communication passage via a check valve.

[0021] In the present invention, even if the switching valve is configured to allow the flow of liquid between the first connecting passage and the tank through the throttle, the provision of the second connecting passage and the check valve enables the liquid to be quickly supplied from the tank to the first cylinder chamber and the second cylinder chamber. As a result, it is possible to prevent the first cylinder chamber and the second cylinder chamber from becoming negative pressure. Further, since the tank communicates with the first connecting passage and the second connecting passage at the lower bottom, it is possible to prevent gas from mixing into the liquid supplied to the first cylinder chamber and the second cylinder chamber.

Effect of the Invention

[0022] According to the present invention, it is possible to provide an operation assist device capable of stable walking operation.

Brief Description of the Drawings

[0023] [Figure 1] It is a side view of an operation assist device according to an embodiment of the present invention. [Figure 2] It is a longitudinal sectional view of an operation assist device according to an embodiment of the present invention. [Figure 3] It is a sectional view taken along line III-III of FIG. 1. [Figure 4] It is a sectional view showing a state in which the lower leg member rotates in the bending direction and the foot member rotates in the plantar flexion direction. [Figure 5] It is a sectional view of the switching valve, shown corresponding to FIG. 2. [Figure 6] It is a sectional view showing a state in which the switching valve is switched to a plurality of throttle positions. [Figure 7] It is a hydraulic circuit diagram of an operation assist device according to an embodiment of the present invention. [Figure 8] It is a diagram for explaining the walking operation when the user walks on flat ground and when ascending and descending stairs.

Mode for Carrying Out the Invention

[0024] The following describes a hydraulic prosthesis 1 as an action assist device according to an embodiment of the present invention, with reference to Figures 1 to 8. In the hydraulic prosthesis 1, hydraulic fluid is used as the liquid flowing inside the hydraulic prosthesis 1. The liquid used in the hydraulic prosthesis 1 can be any incompressible fluid, and other liquids such as hydraulic water may also be used.

[0025] In the following, the direction in which the lower leg is bent relative to the thigh (bringing the calf closer to the thigh) will be referred to as the "flexion direction," and the direction in which the lower leg is extended relative to the thigh (bringing the calf away from the thigh) will be referred to as the "extension direction." Furthermore, the direction in which the foot is bent relative to the lower leg (bringing the toes closer to the lower leg) will be referred to as the "dorsiflexion direction," and the direction in which the foot is extended relative to the lower leg (bringing the toes away from the lower leg) will be referred to as the "plantarflexion direction." In addition, the time when the foot is on the ground will be referred to as the "stance phase," and the time when the foot is off the ground will be referred to as the "swing phase."

[0026] First, the overall configuration of the hydraulic prosthetic leg 1 will be explained with reference to Figures 1 to 4.

[0027] Figure 1 is a side view of the hydraulic prosthesis 1. Figure 2 is a longitudinal cross-sectional view of the hydraulic prosthesis 1. Figure 3 is a cross-sectional view along the line III-III in Figure 1. Figure 4 is a cross-sectional view showing the state in Figure 2 where the lower leg member 3 rotates in the flexion direction and the foot member 4 rotates in the plantarflexion direction.

[0028] As shown in Figures 1 to 3, the hydraulic prosthesis 1 is a transfemoral prosthesis used by a person who has had a femoral amputation. The hydraulic prosthesis 1 comprises a lower leg member 3 to which a support member 2 is rotatably connected and to which a foot member 4 that touches the ground is rotatably connected; a first hydraulic cylinder 7 provided on the lower leg member 3 and connected to the support member 2; and a second hydraulic cylinder 8 provided on the lower leg member 3 and connected to the foot member 4.

[0029] The support member 2 is attached to the user's thigh and supports the thigh. The support member 2 has a socket 2a to which the cut end (severed portion) of the user's thigh is attached, and a support member side connecting portion 2b which is connected to the lower leg member 3 via a first pivot shaft 51. The socket 2a is provided on the upper part of the support member side connecting portion 2b. The support member side connecting portion 2b is provided with a first cylinder mounting portion 21 to which the first link 72 of the first hydraulic cylinder 7 (described later) is rotatably attached. The first cylinder mounting portion 21 is provided at the rear end of the support member side connecting portion 2b. Furthermore, a rotation restricting portion 22 is provided in front of the first pivot shaft 51 on the support member side connecting portion 2b, which abuts against the rotation restricting portion 35a of the lower leg member 3 (described later). A connecting portion 2c is provided between the socket 2a and the support member side connecting portion 2b to connect them. When a user applies a new hydraulic prosthesis 1, they can do so without changing the socket they were using by attaching a commercially available joint to the connection part 2c.

[0030] As shown in Figures 1 to 3, the lower leg member 3 is rotatably connected to the support member 2 in the bending and extension directions. The lower leg member 3 has a first frame 31 as a first member connected to the support member 2, a second frame 32 as a second member connected to the foot member 4, and a spacer 33 provided between the first frame 31 and the second frame 32 as a length adjustment member that can adjust the length of the lower leg member 3. In the lower leg member 3, the first frame 31, the spacer 33, and the second frame 32 are provided in this order from the top.

[0031] The first frame 31 has a first main body portion 34 and a first connecting portion 35 provided on the upper surface of the first main body portion 34 and connected to the support member 2. The first connecting portion 35 is fixed to the upper surface of the first main body portion 34 by fastening members such as bolts. The first connecting portion 35 is rotatably connected to the support member 2 via a first pivot shaft 51. As a result, as shown in Figure 4, the support member 2 is rotatable with respect to the first frame 31 about the first pivot shaft 51. As shown in Figure 1, the first connecting portion 35 is provided with rotation restricting portions 35a and 35b that contact the rotation restricting portion 22 of the support member 2. When the rotation restricting portion 35a contacts the rotation restricting portion 22, it restricts the rotation of the support member 2 in the extension direction, and when the rotation restricting portion 35b contacts the rotation restricting portion 22, it restricts the rotation of the support member 2 in the bending direction.

[0032] The second frame 32 has a second main body portion 36 and a second connecting portion 37 provided on the lower surface of the second main body portion 36 and connected to the foot member 4. The second connecting portion 37 is fixed to the lower surface of the second main body portion 36 by fastening members such as bolts. The second connecting portion 37 is rotatably connected to the foot member 4 via a second pivot shaft 61. As a result, as shown in Figure 4, the foot member 4 is rotatably connected to the lower leg member 3 in the plantarflexion and dorsiflexion directions. The second connecting portion 37 is provided with a rotation restricting portion 37a that abuts against a rotation restricting portion 41 of the foot member 4 (described later) and a rotation restricting portion 37b that abuts against a rotation restricting portion 42 of the foot member 4 (described later) (see Figure 1).

[0033] The spacer 33 is for adjusting the vertical length of the lower leg member 3 and is provided between the first frame 31 and the second frame 32. By adjusting the length of the spacer 33 according to the length of the user's opposite leg, the user's left and right legs can be made to match. Specifically, the user's left and right legs can be made to match by replacing the spacer 33 with one formed to the appropriate length. Alternatively, the spacer 33 may be formed to be able to adjust its own length, so that the user's left and right legs can be made to match without replacing the spacer 33. The spacer 33 is fixed to the lower surface of the first main body portion 34 of the first frame 31 and to the upper surface of the second main body portion 36 of the second frame 32, respectively.

[0034] Thus, the lower leg member 3 is formed by integrally comprising the first frame 31, the second frame 32, and the spacer 33. Furthermore, within the lower leg member 3, there is a first cylinder chamber 71 of the first hydraulic cylinder 7, a second cylinder chamber 81 of the second hydraulic cylinder 8, a first connecting passage 55 and a second connecting passage 56 that connect the first cylinder chamber 71 and the second cylinder chamber 81, and a tank 58 which is a space for storing hydraulic fluid. The internal structure of the lower leg member 3 will be described in detail later.

[0035] The foot member 4 is formed in the same shape as a healthy person's foot so that shoes or the like can be worn on it. The foot member 4 has a main body 4a that touches the ground and a joint 4b that is connected to the lower leg member 3. The joint 4b has a second cylinder mounting portion 43 to which the second link 82 of the second hydraulic cylinder 8, which will be described later, is rotatably attached. As shown in Figure 2, the second cylinder mounting portion 43 is provided in front of the second pivot axis 61 on the foot member 4.

[0036] The joint portion 4b has a rotation restricting portion 41 that contacts the rotation restricting portion 37a of the lower leg member 3, and a rotation restricting portion 42 that contacts the rotation restricting portion 37b of the lower leg member 3. The rotation restricting portion 41 is provided in front of the lower leg member 3. When the rotation restricting portion 41 contacts the rotation restricting portion 37a of the lower leg member 3, it restricts the rotation of the foot member 4 in the dorsiflexion direction. The rotation restricting portion 42 is provided in rear of the lower leg member 3. When the rotation restricting portion 42 contacts the rotation restricting portion 37b of the lower leg member 3, it restricts the rotation of the foot member 4 in the plantarflexion direction. A connecting portion 4c is provided between the main body portion 4a and the joint portion 4b of the foot member 4 to connect the two. When a user applies a new hydraulic prosthesis 1, they can apply the hydraulic prosthesis 1 without changing the main body portion of the foot member they were using by attaching a commercially available joint to the connecting portion 4c.

[0037] A torsion coil spring 9 is provided on the second pivot shaft 61 that connects the lower leg member 3 and the foot member 4. The torsion coil spring 9 holds the foot member 4 in a position tilted approximately 90 degrees relative to the lower leg member 3, as shown in Figures 1 and 2.

[0038] As shown in Figure 2, in the hydraulic prosthesis 1 of this embodiment, when the support member 2 rotates relative to the lower leg member 3 due to the user's movement, the first hydraulic cylinder 7 extends and retracts. The first hydraulic cylinder 7 includes a first cylinder chamber 71 formed within the lower leg member 3, a first piston 73 slidably inserted into the first cylinder chamber 71, a first link 72 rotatably connected to the first piston 73 and the support member 2, and a first pressure chamber 71a partitioned within the first cylinder chamber 71 by the first piston 73, the volume of which decreases and the hydraulic fluid is discharged when the first hydraulic cylinder 7 retracts.

[0039] The first cylinder chamber 71 is provided in the first main body portion 34 of the first frame 31 and opens above the first main body portion 34. In other words, the first main body portion 34 functions as a cylinder tube that partitions the first cylinder chamber 71. By providing the first piston 73 in the first cylinder chamber 71, the first pressure chamber 71a is partitioned below the first cylinder chamber 71. As shown in Figure 3, in the hydraulic prosthesis 1 of this embodiment, the first cylinder chamber 71 is not sealed by the first connecting portion 35 of the first frame 31. Therefore, the area above the first piston 73 in the first cylinder chamber 71 is at atmospheric pressure. A sealing member is provided on the outer circumferential surface of the first piston 73, blocking the flow of hydraulic fluid between the outer circumferential surface of the first piston 73 and the inner circumferential surface of the first cylinder chamber 71. The first communication passage 55 and the second communication passage 56 (see Figure 3) are connected at the bottom of the lower part of the first pressure chamber 71a.

[0040] The first link 72 moves forward and backward relative to the first cylinder chamber 71 when the support member 2 rotates relative to the lower leg member 3 due to the user's movement. Specifically, as shown in Figure 4, when the support member 2 rotates in the bending direction relative to the lower leg member 3, the first link 72 enters the first cylinder chamber 71, causing the first piston 73 to slide downward and the first hydraulic cylinder 7 to contract. On the other hand, when the support member 2 rotates in the extension direction relative to the lower leg member 3, the first link 72 exits the first cylinder chamber 71, causing the first piston 73 to slide upward and the first hydraulic cylinder 7 to extend.

[0041] In the hydraulic prosthesis 1 of this embodiment, the support member 2 rotates relative to the lower leg member 3 due to the user's movement, causing the first hydraulic cylinder 7 to extend and retract. As the first hydraulic cylinder 7 extends and retracts, the second hydraulic cylinder 8 extends and retracts, causing the foot member 4 to rotate. In addition, in the hydraulic prosthesis 1, the foot member 4 rotates relative to the lower leg member 3 due to the user's movement, causing the second hydraulic cylinder 8 to extend and retract. As the second hydraulic cylinder 8 extends and retracts, the first hydraulic cylinder 7 extends and retracts, causing the support member 2 to rotate.

[0042] As shown in Figure 2, the second hydraulic cylinder 8 includes a second cylinder chamber 81 formed within the lower leg member 3, a second piston 83 slidably inserted into the second cylinder chamber 81, a second link 82 rotatably connected to the second piston 83 and the foot member 4, and a second pressure chamber 81a partitioned within the second cylinder chamber 81 by the second piston 83, the volume of which decreases and the hydraulic fluid is discharged when the second hydraulic cylinder 8 is retracted.

[0043] The second cylinder chamber 81 is provided in the second main body portion 36 of the second frame 32 and opens to the lower part of the second main body portion 36. In other words, the second main body portion 36 functions as a cylinder tube that partitions the second cylinder chamber 81. By providing the second piston 83 in the second cylinder chamber 81, a second pressure chamber 81a is partitioned above the second cylinder chamber 81. As shown in Figure 3, in the hydraulic prosthesis 1 of this embodiment, the second cylinder chamber 81 is not sealed by the second connecting portion 37 of the second frame 32. Therefore, the area below the second piston 83 in the second cylinder chamber 81 is at atmospheric pressure. A sealing member is provided on the outer circumferential surface of the second piston 83, blocking the flow of hydraulic fluid between the outer circumferential surface of the second piston 83 and the inner circumferential surface of the second cylinder chamber 81. The upper end of the second pressure chamber 81a is connected to the first communication passage 55 and the second communication passage 56 (see Figure 3).

[0044] When the second hydraulic cylinder 8 extends and retracts in conjunction with the extension and retraction of the first hydraulic cylinder 7, hydraulic fluid is supplied to and discharged from the second pressure chamber 81a, and the second link 82 moves back and forth relative to the second cylinder chamber 81, causing the foot member 4 to rotate relative to the lower leg member 3. Specifically, when hydraulic fluid is discharged from the second pressure chamber 81a, the second piston 83 slides upward, the second link 82 enters the second cylinder chamber 81, and the second hydraulic cylinder 8 contracts. As a result, the foot member 4 rotates in the dorsiflexion direction relative to the lower leg member 3. On the other hand, as shown in Figure 4, when hydraulic fluid is supplied to the second pressure chamber 81a, as shown in Figure 4, the second piston 83 slides downward, the second link 82 exits the second cylinder chamber 81, and the second hydraulic cylinder 8 extends. As a result, the foot member 4 rotates in the plantarflexion direction relative to the lower leg member 3.

[0045] In this embodiment, the volume of the second cylinder chamber 81 is larger than the volume of the first cylinder chamber 71. Specifically, the inner diameter of the second cylinder chamber 81 is larger than the inner diameter of the first cylinder chamber 71. Therefore, the first hydraulic cylinder 7 is more easily expanded and contracted than the second hydraulic cylinder 8. In other words, the support member 2 is more easily rotated than the leg member 4.

[0046] Next, we will explain in detail the configuration of the oil passages within the lower leg member 3.

[0047] Figure 7 shows the hydraulic circuit 100 of the hydraulic prosthesis 1. As shown in Figures 2, 3, and 7, a first communication passage 55 and a second communication passage 56 are formed within the lower leg member 3, connecting the first pressure chamber 71a of the first hydraulic cylinder 7 and the second pressure chamber 81a of the second hydraulic cylinder 8. The first communication passage 55 and the second communication passage 56 extend vertically and are provided parallel to each other. In other words, in this embodiment, the communication passages connecting the first pressure chamber 71a and the second pressure chamber 81a include the first communication passage 55 and the second communication passage 56. Figure 2 shows a cross-sectional view passing through the first communication passage 55. The lower leg member 3 is formed by integrating the first frame 31, the second frame 32, and the spacer 33 so that they cannot rotate relative to each other. Therefore, during the operation of the hydraulic prosthesis 1, the relative position between the first cylinder chamber 71 provided in the first main body portion 34 of the first frame 31 and the second cylinder chamber 81 provided in the second main body portion 36 of the second frame 32 does not change. As a result, in the hydraulic prosthesis 1, the first communication passage 55 and the second communication passage 56 that connect the first pressure chamber 71a and the second pressure chamber 81a can be provided as passages formed within the lower leg member 3 rather than as external piping. Furthermore, since the spacer 33 does not have cylinder chambers or the like, and only has the first communication passage 55 and the second communication passage 56 that extend in the vertical direction, the length in the vertical direction can be easily adjusted. This makes it possible to match the length of the user's left and right legs by replacing the spacer 33 with one of the appropriate length or by adjusting the length of the spacer 33.

[0048] As shown in Figures 2 and 7, a tank 58 is formed in the first main body portion 34 of the first frame 31, which is a space for storing the hydraulic fluid supplied to and discharged from the first cylinder chamber 71 and the second cylinder chamber 81. By forming the tank 58 space in the first main body portion 34, the weight of the lower leg member 3 is reduced. As shown in Figure 2, the tank 58 opens to the side of the first main body portion 34, and this opening is covered by a covering portion 58a. The covering portion 58a is fastened to the first main body portion 34 by fastening members such as bolts, and the covering portion 58a prevents the hydraulic fluid in the tank 58 from leaking to the outside. An opening (not shown) that opens to the outside of the first frame 31 and a cap (not shown) that can be detachably attached to the opening are provided at the top of the tank 58. When the cap is removed, the hydraulic fluid in the tank 58 can be supplied to and discharged through the opening, and when the cap is attached to the opening, the inside of the tank 58 is sealed. This makes maintenance of the hydraulic prosthesis 1 easier. As shown in Figures 2 and 5, the tank 58 has a first opening 58b at its lower bottom that communicates with the first communication passage 55, and a second opening 58c (see Figure 3) at its lower bottom that communicates with the second communication passage 56. Here, "bottom" refers to the area that is always covered by hydraulic fluid even if the hydraulic fluid level in the tank 58 fluctuates. In the hydraulic circuit 100 shown in Figure 7, the third communication passage 57 corresponds to the flow path from the tank 58 to the first opening 58b and the second opening 58c. In this way, because the tank 58 communicates with the communication passages 55 and 56 at its lower bottom, it is prevented from mixing gas with the hydraulic fluid supplied from the tank 58 to the first pressure chamber 71a and the second pressure chamber 81a.

[0049] Furthermore, as shown in Figures 1, 2, and 5, the hydraulic prosthesis 1 is equipped with an externally operable operating unit 40 (see Figure 1), and an adjustment unit 40b of the operating unit 40 is provided inside the tank 58 through an operating unit-side opening 40a provided in the tank 58 (see Figures 2 and 5). In this embodiment, the operating unit 40 is a lever that can be rotated by the user and is provided on the first main body portion 34 of the first frame 31. The adjustment unit 40b rotates along the inner circumferential surface of the operating unit-side opening 40a as the operating unit 40 is rotated. By operating the operating unit 40, the position of the switching valve 90 that switches the flow of hydraulic fluid between the first communication passage 55 and the tank 58 is selected. Note that the configuration of the operating unit 40 is not limited to a lever, as long as the position of the switching valve 90 can be selected by operating the operating unit 40.

[0050] As shown in Figure 2, an air vent valve 58d is provided above the tank 58 for air venting. The air vent valve 58d can be opened and closed manually from the outside. By opening the air vent valve 58d, it is possible to discharge gas mixed into the tank 58 to the outside and prevent the inside of the tank 58 from becoming negative pressure. In addition, the first frame 31 is provided with an air vent passage (not shown) that connects the tank 58 to the first pressure chamber 71a, separate from the first communication passage 55 and the second communication passage 56. The air vent passage can be opened and closed manually from the outside using a lever or the like. In the hydraulic prosthesis 1, the first communication passage 55 and the second communication passage 56, which connect the first pressure chamber 71a of the first hydraulic cylinder 7 and the second pressure chamber 81a of the second hydraulic cylinder 8, are provided extending in the vertical direction. Therefore, even if gas is mixed into the first communication passage 55 and the second communication passage 56 from the outside, the gas is guided to the first pressure chamber 71a located above. Therefore, by operating and opening the air vent passage from the outside, the mixed gas can be easily guided to the tank 58 and discharged to the outside by the air vent valve 58d. Thus, since the mixed gas can be discharged to the outside without disassembling the hydraulic prosthesis 1, maintenance of the hydraulic prosthesis 1 becomes easier. In addition, a component such as a cap that integrates the function of the air vent valve 58d and the function of the cap for supplying and discharging the hydraulic fluid in the tank 58 may be provided.

[0051] The hydraulic prosthesis 1 includes a switching valve 90 (see Figures 2 and 7) provided in the first communication passage 55 for switching the flow of hydraulic fluid between the first communication passage 55 and the tank 58, and a check valve 95 (see Figure 7) provided in the second communication passage 56 for allowing only the flow of hydraulic fluid from the tank 58 to the second communication passage 56. As shown in Figure 7, the switching valve 90 has a shut-off position 90A that shuts off the flow of liquid from the first communication passage 55 to the tank 58, and a communication position 90B that allows the flow of hydraulic fluid between the first communication passage 55 and the tank 58. The communication position 90B consists of a plurality of throttling positions (first throttling position 90C, second throttling position 90D, third throttling position 90E) in which the amount of liquid throttling differs from each other. As described above, a switching valve 90 is provided in the first communication passage 55 and a check valve 95 is provided in the second communication passage 56. Therefore, hydraulic fluid is supplied from the tank 58 to the first pressure chamber 71a of the first hydraulic cylinder 7 and the second pressure chamber 81a of the second hydraulic cylinder 8 through the check valve 95 and the second communication passage 56. In other words, even if the switching valve 90 is configured to allow the flow of hydraulic fluid between the first communication passage 55 and the tank 58 through a throttle, the provision of the second communication passage 56 and the check valve 95 ensures that hydraulic fluid is quickly supplied from the tank 58 to the first pressure chamber 71a and the second pressure chamber 81a. This prevents the first pressure chamber 71a and the second pressure chamber 81a from becoming negative pressure. Furthermore, the hydraulic fluid in the first pressure chamber 71a of the first hydraulic cylinder 7 and the second pressure chamber 81a of the second hydraulic cylinder 8 is discharged to the tank 58 through the switching valve 90 and the first communication passage 55.

[0052] As shown in Figure 5, the switching valve 90 is inserted into an opening 55a that opens on the outer surface of the lower leg member 3 and communicates with the first communication passage 55, and is provided in the first communication passage 55. The switching valve 90 has a housing 91 having a hollow portion, a poppet 92 as a valve body that is slidably provided inside the housing 91, and a spring 93 as a biasing member that biases the poppet 92 in the closing direction.

[0053] The housing 91 is provided in a bottomed cylindrical shape with a flange, and its outer surface is fixed by screw fastening into the opening 55a. The housing 91 does not enter the first communication passage 55.

[0054] The poppet 92 has a housing portion 92a that houses a part of the spring 93, a plurality of poppet internal passages 92b that penetrate radially through the poppet 92, a throttling portion 92c that is exposed from the housing 91 and inserted into the first opening 58b of the tank 58, and a valve portion 92e that is provided between the poppet internal passages 92b and the throttling portion 92c and has a seat portion 92d formed thereon. The upper and lower parts of the switching valve 90 in the first communication passage 55 are in communication through the poppet internal passages 92b. The spring 93 is housed in the housing portion 92a and biases the poppet 92 in the valve closing direction (left side in Figure 5). As a result, the seat portion 92d seats on the valve seat 58e provided in the first opening 58b of the tank 58. When the seat portion 92d is seated on the valve seat 58e, the switching valve 90 is in the shut-off position 90A, and the flow of hydraulic fluid from the first communication passage 55 to the tank 58 is shut off.

[0055] The throttling portion 92c is provided in continuity with the valve portion 92e. A groove-shaped throttling portion 92f is provided along the axial direction on a part of the outer circumferential surface of the throttling portion 92c. The throttling portion 92f has, in order from the base end side (right side in Figure 5), a first throttling portion 92g with the smallest flow path cross-sectional area, a second throttling portion 92h with a larger flow path cross-sectional area than the first throttling portion 92g, and a third throttling portion 92i with the largest flow path cross-sectional area. The first throttling portion 92g, the second throttling portion 92h, and the third throttling portion 92i are formed continuously in the axial direction. The first throttling portion 92g, the second throttling portion 92h, and the third throttling portion 92i correspond to multiple throttling positions 90C, 90D, and 90E of the switching valve 90, respectively. The throttling portion 92f may be provided around the entire circumference of the outer circumferential surface of the throttling portion 92c.

[0056] The adjustment portion 40b of the operating portion 40 abuts against the tip of the throttling portion 92c. As shown in Figures 6(A), (B), and (C), when the adjustment portion 40b is rotated by operating the operating portion 40, the adjustment portion 40b gradually presses against the poppet 92 against the biasing force of the spring 93. As a result, the seat portion 92d separates from the valve seat 58e, the switching valve 90 moves to the communication position 90B, and the flow of hydraulic fluid from the first communication passage 55 toward the tank 58 is permitted. In the state shown in Figure 6(A), the flow of hydraulic fluid from the first communication passage 55 toward the tank 58 is restricted by the first throttling portion 92g (first throttling position 90C). In the state shown in Figure 6(B), the flow of hydraulic fluid from the first communication passage 55 toward the tank 58 is restricted by the second throttling portion 92h (second throttling position 90D). In the state shown in Figure 6(C), the flow of hydraulic fluid from the first communication passage 55 to the tank 58 is restricted by the third throttling section 92i (third throttling position 90E). In this way, the switching valve 90 is provided with multiple throttling positions 90C, 90D, and 90E. In the switching valve 90, the amount of fluid restriction is greatest at the first throttling position 90C, and the amount of fluid restriction is least greatest at the third throttling position 90E.

[0057] When the switching valve 90 is in the shut-off position 90A, the flow of hydraulic fluid from the first communication passage 55 toward the tank 58 is shut off, causing hydraulic fluid to move between the first pressure chamber 71a of the first hydraulic cylinder 7 and the second pressure chamber 81a of the second hydraulic cylinder 8. In other words, when the switching valve 90 is in the shut-off position 90A, when the first hydraulic cylinder 7 contracts, hydraulic fluid is directed into the second pressure chamber 81a, and the second hydraulic cylinder 8 extends. When the switching valve 90 is in the open position 90B, in order to allow the flow of hydraulic fluid from the first communication passage 55 toward the tank 58, a portion of the hydraulic fluid moving between the first pressure chamber 71a and the second pressure chamber 81a is discharged into the tank 58. In other words, when the switching valve 90 is in the communication position 90B, when the first hydraulic cylinder 7 contracts, hydraulic fluid is guided into the second pressure chamber 81a and discharged into the tank 58, so the second hydraulic cylinder 8 extends less than when it is in the shut-off position 90A. Furthermore, the communication position 90B consists of multiple throttle positions (first throttle position 90C, second throttle position 90D, and third throttle position 90E), and the flow rate of hydraulic fluid discharged into the tank 58 is controlled by these multiple throttle positions.

[0058] Furthermore, since known technology can be used for the configuration of the check valve 95, a detailed explanation will be omitted.

[0059] As described above, in the hydraulic prosthesis 1, the first cylinder chamber 71 and the second cylinder chamber 81 are formed within the lower leg member 3, and connecting passages 55 and 56 that connect the first cylinder chamber 71 and the second cylinder chamber 81 are formed within the lower leg member 3. In other words, the connecting passages 55 and 56 that connect the first cylinder chamber 71 and the second cylinder chamber 81 are not provided on the outside of the lower leg member 3. As a result, there are no external pipes exposed from the lower leg member 3, so it is prevented from getting caught on pipes during walking. Therefore, the hydraulic prosthesis 1 enables stable walking motion.

[0060] Furthermore, in the hydraulic prosthesis 1, the first link 72 is rotatably connected to the first piston 73 and the support member 2, and the second link 82 is rotatably connected to the second piston 83 and the foot member 4. Therefore, when the support member 2 rotates relative to the lower leg member 3 due to the user's movement, the first piston 73 slides within the first cylinder chamber 71, and consequently, the second piston 83 slides within the second cylinder chamber 81, causing the foot member 4 to rotate relative to the lower leg member 3. Also, when the foot member 4 rotates relative to the lower leg member 3 due to the user's movement, the second piston 83 slides within the second cylinder chamber 81, and consequently, the first piston 73 slides within the first cylinder chamber 71, causing the support member 2 to rotate relative to the lower leg member 3. As a result, walking motion is possible in the hydraulic prosthesis 1 in which the first cylinder chamber 71 and the second cylinder chamber 81 are formed within the lower leg member 3.

[0061] Furthermore, in the hydraulic prosthesis 1, a tank 58, which is a space, is provided within the lower leg member 3, so that the tank 58 is not exposed to the outside of the lower leg member 3. As a result, there is no external piping connecting the tank 58 to the connecting passages 55 and 56, so the risk of getting caught on piping during walking is prevented. In addition, since the tank 58 communicates with the connecting passages 55 and 56 at its lower bottom, the mixing of gas with the liquid supplied to the first cylinder chamber 71 and the second cylinder chamber 81 is prevented.

[0062] Furthermore, in the hydraulic prosthesis 1, the communication passage connecting the first cylinder chamber 71 and the second cylinder chamber 81 includes a first communication passage 55 equipped with a switching valve 90 and a second communication passage 55 equipped with a check valve 95. Therefore, even if the switching valve 90 is configured to allow the flow of hydraulic fluid between the first communication passage 55 and the tank 58 through a throttle, the presence of the second communication passage 56 and the check valve 95 ensures that hydraulic fluid is quickly supplied from the tank 58 to the first cylinder chamber 71 and the second cylinder chamber 81. This prevents the first cylinder chamber 71 and the second cylinder chamber 81 from becoming negatively pressurized. In addition, since the tank 58 communicates with the first communication passage 55 and the second communication passage 56 at its lower bottom, it prevents gas from mixing with the liquid supplied to the first cylinder chamber 71 and the second cylinder chamber 81.

[0063] Furthermore, in the hydraulic prosthesis 1, only vertically extending passages 55 and 56 are provided within the spacer 33, and no other cylinder chambers or the like are provided, so the vertical length of the spacer 33 can be easily adjusted. Therefore, the vertical length of the lower leg member 3 can be easily adjusted using the spacer 33, and the lengths of the user's left and right legs can be matched.

[0064] Next, we will explain the walking motion using the hydraulic prosthesis 1 with reference to Figures 2, 7, and 8.

[0065] Figure 8 shows the operation of the first hydraulic cylinder 7 and the second hydraulic cylinder 8 when the user walks on level ground and when ascending and descending stairs. In Figure 8, the leg posture shown by the solid line is the leg to which the hydraulic prosthesis 1 is attached, and the leg posture shown by the dashed line is the other leg to which the hydraulic prosthesis 1 is not attached. In Figure 8, the user walks towards the right in the figure.

[0066] First, let's explain the case where the user is walking on flat ground.

[0067] When the user walks forward, they step forward with one leg fitted with the hydraulic prosthesis 1. As shown in leg posture A, when the user steps forward with one leg fitted with the hydraulic prosthesis 1, the support member 2 rotates in the bending direction due to the user's movement, the first link 72 enters the first cylinder chamber 71, the first piston 73 slides downward, and the first hydraulic cylinder 7 contracts. As a result, the hydraulic fluid in the first pressure chamber 71a is guided into the second pressure chamber 81a, the second piston 83 slides downward, the second link 82 exits the second cylinder chamber 81, and the second hydraulic cylinder 8 extends. Therefore, the foot member 4 rotates in the plantarflexion direction. When the bottom of the foot member 4 that has stepped forward touches the ground, the support member 2 is slightly bent, and the foot member 4 is slightly rotated in the plantarflexion direction. From this state, as shown in leg posture B, when the user moves forward further, the lower leg member 3 tilts forward due to the user's movement, causing the foot member 4 to rotate in the dorsiflexion direction, the second link 82 enters the second cylinder chamber 81, the second piston 83 slides upward, and the second hydraulic cylinder 8 contracts. As a result, the hydraulic fluid in the second pressure chamber 81a is drawn into the first pressure chamber 71a, the first piston 73 slides upward, the first link 72 exits the first cylinder chamber 71, and the first hydraulic cylinder 7 extends. Therefore, the support member 2 rotates in the extension direction.

[0068] Here, when walking on flat ground, the user switches the switching valve 90 to the second throttle position 90D or the third throttle position 90E. When the switching valve 90 is switched to the second throttle position 90D or the third throttle position 90E, when the support member 2 rotates in the bending direction, a portion of the hydraulic fluid discharged from the first pressure chamber 71a of the first hydraulic cylinder 7 is discharged to the tank 58 through the second throttle section 92h or the third throttle section 92i. In other words, the flow rate of hydraulic fluid is restricted when the first hydraulic cylinder 7 attempts to contract. As a result, the lower leg member 3 rotates gently in the bending direction relative to the support member 2. In this way, by switching the switching valve 90 to the second throttle position 90D or the third throttle position 90E, the cushioning effect when the support member 2 rotates in the bending direction can be adjusted. This reduces the impact on the user when walking on flat ground.

[0069] Next, we will explain the case of a user wearing a hydraulic prosthesis 1 on one leg ascending or descending stairs.

[0070] When the user ascends the stairs, they step one leg, fitted with the hydraulic prosthesis 1, onto the next step. As shown in leg position C, when the user steps one leg, fitted with the hydraulic prosthesis 1, onto the next step, the support member 2 rotates in the bending direction due to the user's movement, the first link 72 enters the first cylinder chamber 71, the first piston 73 slides downward, and the first hydraulic cylinder 7 contracts. As a result, the hydraulic fluid in the first pressure chamber 71a is drawn into the second pressure chamber 81a, the second piston 83 slides downward, the second link 82 exits the second cylinder chamber 81, and the second hydraulic cylinder 8 extends. Therefore, the foot member 4 rotates in the plantarflexion direction. When the bottom of the foot member 4 touches the stairs, the support member 2 is bent and the foot member 4 is rotated in the plantarflexion direction. From this state, as shown in leg posture D, when the user steps the other leg up to the next step, the user's movement causes the lower leg member 3 to tilt forward, causing the foot member 4 to rotate in the dorsiflexion direction, the second link 82 to enter the second cylinder chamber 81, the second piston 83 to slide upward, and the second hydraulic cylinder 8 to contract. As a result, the hydraulic fluid in the second pressure chamber 81a is drawn into the first pressure chamber 71a, the first piston 73 slides upward, the first link 72 retracts from the first cylinder chamber 71, and the first hydraulic cylinder 7 extends. Therefore, the support member 2 rotates in the extension direction.

[0071] Here, when the user is climbing stairs, the user switches the switching valve 90 to the shut-off position 90A. When the user is climbing stairs, the amount of rotation of the support member 2 and the amount of rotation of the foot member 4 are required to be larger compared to when walking on flat ground. Specifically, it is required that the entire amount of hydraulic fluid in the first pressure chamber 71a and the second pressure chamber 81a moves in conjunction, and the amount of rotation of the support member 2 is maximized. When the switching valve 90 is switched to the shut-off position 90A, the flow of hydraulic fluid from the first communication passage 55 to the tank 58 is shut off, and the hydraulic fluid in the first pressure chamber 71a and the second pressure chamber 81a is not discharged to the tank 58. Therefore, when the support member 2 rotates in the bending direction relative to the lower leg member 3, a large amount of hydraulic fluid moves from the first pressure chamber 71a to the second pressure chamber 81a in conjunction with it, and the foot member 4 rotates significantly in the plantarflexion direction relative to the lower leg member 3 (leg posture C). Furthermore, when the foot member 4 rotates in dorsiflexion relative to the lower leg member 3, a large amount of hydraulic fluid moves from the second pressure chamber 81a into the first pressure chamber 71a in conjunction with this, causing the support member 2 to rotate significantly in extension relative to the lower leg member 3 (leg posture D). Therefore, even when climbing stairs, the user can perform a natural walking motion using the hydraulic prosthesis 1.

[0072] Furthermore, when the user descends the stairs, they step down one step with the leg wearing the hydraulic prosthesis 1. As shown in leg posture E, when the user steps down one step with the leg wearing the hydraulic prosthesis 1, the support member 2 rotates slightly in the bending direction due to the user's movement, the first link 72 enters the first cylinder chamber 71, the first piston 73 slides downward, and the first hydraulic cylinder 7 contracts. At this point, if the hydraulic fluid in the first pressure chamber 71a is guided into the second pressure chamber 81a, the second piston 83 slides downward, the second hydraulic cylinder 8 extends, and the foot member 4 rotates in the plantarflexion direction. If the foot member 4 rotates in the plantarflexion direction, the foot member 4 will not be parallel to the step being taken, resulting in instability. Therefore, when the user descends the stairs, the user should switch the switching valve 90 to the first throttle position 90C or the second throttle position 90D. When the switching valve 90 is switched to the first throttle position 90C or the second throttle position 90D (communication position 90B), the first communication passage 55 and the tank 58 are connected. As a result, the hydraulic fluid in the first pressure chamber 71a can be discharged into the tank 58, and even if the support member 2 rotates relative to the lower leg member 3, the foot member 4 hardly rotates in conjunction with it. Therefore, the foot member 4 rotates in the dorsiflexion direction with moderate resistance. This reproduces the movement of the knee slowly bending when the user puts their weight on it and descends stairs. At this time, the first hydraulic cylinder 7 and the second hydraulic cylinder 8 also function as dampers. When the bottom of the foot member 4 touches the stairs, the support member 2 is bent.

[0073] From this state, as shown in leg posture F, when the user steps the other leg down one step, the support member 2 rotates further in the bending direction due to the user's movement. As described above, the switching valve 90 is switched to the first throttle position 90C or the second throttle position 90D. As a result, the hydraulic fluid in the first pressure chamber 71a can be discharged to the tank 58, and even if the support member 2 rotates further in the bending direction, it is possible to hold the foot member 4 without rotating in the plantarflexion direction in conjunction with it, allowing for a natural walking motion. In addition, when the support member 2 rotates in the bending direction and the first hydraulic cylinder 7 attempts to contract, the flow rate of the hydraulic fluid is restricted by the first throttle section 92g or the second throttle section 92h, so that between leg posture E and leg posture F, the lower leg member 3 rotates slowly in the bending direction relative to the support member 2. Thus, the impact on the user when descending the stairs can be reduced, and the user can descend the stairs safely as the support member 2 rotates slowly in the bending direction. Furthermore, the foot member 4 rotates in the dorsiflexion direction not in conjunction with the rotation of the support member 2, but as a result of the user's movement causing the lower leg member 3 to tilt forward. In other words, when the user descends the stairs, the support member 2 and the foot member 4 rotate independently of each other.

[0074] As described above, the switching valve 90, at the communication position 90B, can adjust the ease of rotation of the support member 2 relative to the lower leg member 3 and the rotation of the foot member 4 linked to the rotation of the support member 2 by using multiple throttling positions 90C, 90D, and 90E. In other words, the cushioning effect when the support member 2 rotates in the bending direction and the linkage of the foot member 4 can be adjusted by using multiple throttling positions 90C, 90D, and 90E. Specifically, when a user is descending stairs, if the support member 2 rotates too quickly in the bending direction, the user may lose their balance and fall. Therefore, when a user is descending stairs, the valve is switched to the first throttling position 90C or the second throttling position 90D, which has a larger throttling amount, so that the support member 2 rotates slowly in the bending direction. This allows the user to descend stairs safely and reduces the impact on the user. Furthermore, when the user is walking on flat ground, the system switches to the second aperture position 90D or the third aperture position 90E, which has a smaller aperture than when descending stairs, allowing the support member 2 to rotate faster in the bending direction than when descending stairs. This enables the user to walk smoothly on flat ground and reduces the impact on the user. In this way, by changing the aperture position depending on whether the user is walking on flat ground or going up and down stairs, appropriate foot movement can be achieved in each situation, and the impact on the user can be appropriately reduced.

[0075] Furthermore, when the user climbs stairs, the switching valve 90 is switched to the shut-off position 90A, so that when the support member 2 rotates relative to the lower leg member 3, the foot member 4 rotates significantly relative to the lower leg member 3, and when the foot member 4 rotates relative to the lower leg member 3, the support member 2 rotates significantly relative to the lower leg member 3. As a result, even when climbing stairs, the user can perform a natural walking motion using the hydraulic prosthesis 1. Thus, with the hydraulic prosthesis 1, a natural walking motion can be achieved by switching the switching valve 90 between the shut-off position 90A and the communication position 90B (restriction positions 90C, 90D, 90E) depending on whether the user is walking on flat ground, climbing stairs, or descending stairs.

[0076] Furthermore, the aperture position of the switching valve 90 is selected by operating the control unit 40. Therefore, the aperture position of the switching valve 90 can be easily selected by operating the control unit 40 from the outside.

[0077] Furthermore, hydraulic fluid can be supplied from the tank 58 to the first pressure chamber 71a of the first hydraulic cylinder 7 and the second pressure chamber 81a of the second hydraulic cylinder 8 not only through the switching valve 90 and the first communication passage 55, but also through the check valve 95 and the second communication passage 56. Therefore, even if the support member 2 rotates significantly in the extension direction relative to the lower leg member 3 and the first hydraulic cylinder 7 extends significantly, hydraulic fluid is supplied from the tank 58 to the first pressure chamber 71a, preventing the first pressure chamber 71a from becoming negative pressure and preventing gas from entering the first pressure chamber 71a.

[0078] Furthermore, the volume of the second hydraulic cylinder 8 (specifically, the volume of the second cylinder chamber 81) is larger than the volume of the first hydraulic cylinder 7 (specifically, the volume of the first cylinder chamber 71). Therefore, the amount of hydraulic fluid supplied and discharged due to the expansion and contraction of the first hydraulic cylinder 7 is less than that of the second hydraulic cylinder 8. As a result, the support member 2 rotates more easily than the foot member 4. In the user's walking motion, the support member 2 rotates more than the foot member 4, so this configuration makes it easier for the support member 2 to rotate, allowing the user to take a natural walking motion.

[0079] Specifically, the "volume of the first hydraulic cylinder 7" is the product of the inner diameter of the first cylinder chamber 71 and the stroke amount of the first piston 73. The "stroke amount of the first piston 73" corresponds to the distance between the mounting point of the first link 72 and the first cylinder mounting part 21 and the first pivot shaft 51. This is because if the distance between the mounting point of the first link 72 and the first cylinder mounting part 21 and the first pivot shaft 51 changes, the stroke amount of the first piston 73 when the support member 2 rotates changes. Specifically, if the distance between the mounting point of the first link 72 and the first cylinder mounting part 21 and the first pivot shaft 51 increases, the stroke amount of the first piston 73 when the support member 2 rotates increases. Furthermore, the "volume of the second hydraulic cylinder 8" is the product of the inner diameter of the second cylinder chamber 81 and the stroke amount of the second piston 83. The "stroke amount of the second piston 83" corresponds to the distance between the mounting portion of the second link 82 and the second cylinder mounting portion 43 and the second pivot shaft 61. In this embodiment, the inner diameter of the second cylinder chamber 81 is larger than the inner diameter of the first cylinder chamber 71, but the configuration is not limited to this, and the inner diameters of the first cylinder chamber 71 and the second cylinder chamber 81 may be the same, and the stroke amount of the second piston 83 may be larger than the stroke amount of the first piston 73.

[0080] Furthermore, the system may determine whether the user is walking on flat ground, climbing stairs, or descending stairs using sensors attached to the hydraulic prosthesis 1 or the user, and automatically operate the control unit 40 to set the optimal position of the switching valve 90 based on the determination result.

[0081] According to the above embodiments, the following effects are achieved.

[0082] In the hydraulic prosthesis 1, the connecting passages 55 and 56 between the first cylinder chamber 71 and the second cylinder chamber 81 are not provided on the outside of the lower leg member 3. This prevents the prosthesis from getting caught on the piping during walking, enabling stable walking motion with the hydraulic prosthesis 1.

[0083] In the hydraulic prosthesis 1, the first link 72 is rotatably connected to the first piston 73 and the support member 2, and the second link 82 is rotatably connected to the second piston 83 and the foot member 4. This enables walking motion in the hydraulic prosthesis 1, in which the first cylinder chamber 71 and the second cylinder chamber 81 are formed within the lower leg member 3.

[0084] In the hydraulic prosthesis 1, a tank 58, which is a space, is provided within the lower leg member 3, so that the tank 58 is not exposed to the outside of the lower leg member 3. This prevents it from getting caught on pipes when walking. Furthermore, since the tank 58 communicates with the connecting passages 55 and 56 at its lower bottom, it prevents gas from mixing with the liquid supplied to the first cylinder chamber 71 and the second cylinder chamber 81.

[0085] In the hydraulic prosthesis 1, a natural walking motion can be achieved by switching the switching valve 90 between the shut-off position 90A and the open position 90B depending on whether the user is walking on flat ground, climbing stairs, or descending stairs. In particular, the hydraulic prosthesis 1 allows adjustment of the cushioning effect and the interlocking of the foot member 4 when the support member 2 rotates in the bending direction using multiple constriction positions 90C, 90D, and 90E. This allows the user to change the constriction position when walking on flat ground or climbing stairs, thereby achieving appropriate foot movement in each situation and appropriately reducing the impact on the user.

[0086] In the hydraulic prosthetic leg 1, the throttle position of the switching valve 90 can be easily selected by operating the control unit 40 from the outside.

[0087] In the hydraulic prosthesis 1, the first hydraulic cylinder 7 is more flexible than the second hydraulic cylinder 8. During the user's walking motion, the support member 2 has a greater range of rotation than the foot member 4. This configuration allows the support member 2 to rotate more easily, enabling the user to walk more naturally.

[0088] In the hydraulic prosthetic leg 1, the spacer 33 is provided only with connecting passages 55 and 56, and no other cylinder chambers or the like are provided, so the vertical length can be easily adjusted. This makes it possible to match the length of the user's left and right legs.

[0089] In the hydraulic prosthesis 1, even though the switching valve 90 is configured to allow the flow of hydraulic fluid between the first communication passage 55 and the tank 58 through a throttle, the provision of a second communication passage 56 and a check valve 95 ensures that hydraulic fluid is quickly supplied from the tank 58 to the first cylinder chamber 71 and the second cylinder chamber 81. This prevents the first cylinder chamber 71 and the second cylinder chamber 81 from becoming negatively pressurized. Furthermore, since the tank 58 communicates with the first communication passage 55 and the second communication passage 56 at its lower bottom, it prevents gas from mixing with the liquid supplied to the first cylinder chamber 71 and the second cylinder chamber 81.

[0090] The configuration, operation, and effects of the embodiments of the present invention will be described below.

[0091] The hydraulic prosthesis 1, as an assistive device for movement, comprises a lower leg member 3 to which a foot member 4 that touches the ground is rotatably connected and to which a support member 2 attached to the user's thigh is rotatably connected; a first hydraulic cylinder 7 that expands and contracts when the support member 2 rotates relative to the lower leg member 3; and a second hydraulic cylinder 8 that rotates the foot member 4. The first hydraulic cylinder 7 has a first cylinder chamber 71 formed within the lower leg member 3, and the second hydraulic cylinder 8 has a second cylinder chamber 81 formed within the lower leg member 3. Communication passages 55 and 56 are formed within the lower leg member 3, connecting the first cylinder chamber 71 and the second cylinder chamber 81.

[0092] In this configuration, the first hydraulic cylinder 7 and the second hydraulic cylinder 8 operate in conjunction. Furthermore, the first cylinder chamber 71 and the second cylinder chamber 81 are formed within the lower leg member 3, and connecting passages 55 and 56 are formed within the lower leg member 3, linking the first cylinder chamber 71 and the second cylinder chamber 81. As a result, there are no external pipes exposed from the lower leg member 3, preventing the wearer from getting caught on pipes while walking.

[0093] Furthermore, the first hydraulic cylinder 7 further includes a first piston 73 slidably inserted into the first cylinder chamber 71, a first link 72 rotatably connected to the first piston 73 and the support member 2, and a first pressure chamber 71a partitioned within the first cylinder chamber 71 by the first piston 73, from which liquid is discharged when the first hydraulic cylinder 7 is retracted. The second hydraulic cylinder 8 further includes a second piston 83 slidably inserted into the second cylinder chamber 81, a second link 82 rotatably connected to the second piston 83 and the leg member 4, and a second pressure chamber 81a partitioned within the second cylinder chamber 81 by the second piston 83, from which liquid is discharged when the second hydraulic cylinder 8 is retracted. The connecting passages 55 and 56 connect the first pressure chamber 71a and the second pressure chamber 81a.

[0094] In this configuration, the first link 72 is rotatably connected to the first piston 73 and the support member 2, and the second link 82 is rotatably connected to the second piston 83 and the foot member 4. Therefore, when the support member 2 rotates relative to the lower leg member 3, the first piston 73 slides within the first cylinder chamber 71, causing the foot member 4 to rotate. This enables walking motion in the motion assist device in which the first cylinder chamber 71 and the second cylinder chamber 81 are formed within the lower leg member 3.

[0095] Furthermore, a tank 58 is formed within the lower leg member 3, which is a space for storing the liquid supplied to and discharged from the first cylinder chamber 71 and the second cylinder chamber 81. The tank 58 communicates with connecting passages 55 and 56 at its lower bottom.

[0096] In this configuration, a tank 58, which is a space, is provided within the lower leg member 3, so that the tank 58 is not exposed to the outside of the lower leg member 3. As a result, there is no external piping connecting the tank 58 to the connecting passages 55 and 56, so the risk of getting caught on piping during walking is prevented. Furthermore, since the tank 58 communicates with the connecting passages 55 and 56 at its lower bottom, the mixing of gas with the liquid supplied to the first cylinder chamber 71 and the second cylinder chamber 81 is prevented.

[0097] Furthermore, the hydraulic prosthesis 1 is provided with a switching valve 90 in the communication passage 55 for switching the flow of liquid between the communication passage 55 and the tank 58. The switching valve 90 has a shut-off position 90A that blocks the flow of liquid from the communication passage 55 to the tank 58, and a communication position 90B that allows the flow of liquid from the communication passage 55 to the tank 58. The communication position 90B consists of a plurality of throttling positions 90C, 90D, and 90E, each with a different amount of liquid throttling. The switching valve 90 is provided with a poppet 92 as a valve body, in which a plurality of throttling sections 92g, 92h, and 92i corresponding to the plurality of throttling positions 90C, 90D, and 90E are formed in a continuous manner in the axial direction.

[0098] In this configuration, when the switching valve 90 is switched to the shut-off position 90A, the flow of liquid from the communication passage 55 to the tank 58 is shut off. Therefore, when the support member 2 rotates in the bending direction relative to the lower leg member 3, the foot member 4 rotates significantly in the plantarflexion direction relative to the lower leg member 3 in conjunction with it, and when the support member 2 rotates in the extension direction relative to the lower leg member 3, the foot member 4 rotates significantly in the dorsiflexion direction relative to the lower leg member 3 in conjunction with it. On the other hand, when the switching valve 90 is switched to the communication position 90B, the communication passage 55 and the tank 58 are connected. Therefore, even if the support member 2 rotates relative to the lower leg member 3, the amount of rotation of the foot member 4 relative to the lower leg member 3 in conjunction with it can be reduced. In this way, by switching the switching valve 90 between the shut-off position 90A and the communication position 90B, a natural walking motion can be achieved. Furthermore, the communication position 90B consists of multiple throttling positions 90C, 90D, and 90E, each with a different amount of liquid throttling. The switching valve 90 is provided with a poppet 92 as a valve body, in which multiple throttling sections 92g, 92h, and 92i corresponding to the multiple throttling positions 90C, 90D, and 90E are formed continuously in the axial direction. Therefore, the ease of rotation of the support member 2 relative to the lower leg member 3 can be adjusted by the multiple throttling positions 90C, 90D, and 90E. In other words, the cushioning effect and the interlocking of the foot member 4 when the support member 2 rotates in the bending direction can be adjusted by the multiple throttling positions 90C, 90D, and 90E. This allows the user to change the throttling position depending on whether they are walking on flat ground or going up and down stairs, thereby enabling appropriate foot movement in each situation and appropriately reducing the impact on the user.

[0099] Furthermore, the hydraulic prosthesis 1 is further equipped with an externally operable control unit 40, and the throttling position of the switching valve 90 is selected by operating the control unit 40.

[0100] In this configuration, the throttle position of the switching valve 90 can be easily selected by operating the control unit 40 from the outside.

[0101] Furthermore, the volume of the second hydraulic cylinder 8 is larger than the volume of the first hydraulic cylinder 7.

[0102] In this configuration, the first hydraulic cylinder 7 is more flexible than the second hydraulic cylinder 8. During the user's walking motion, the support member 2 rotates more than the foot member 4. This configuration allows the support member 2 to rotate more easily, enabling the user to walk naturally.

[0103] Furthermore, the lower leg member 3 includes a first frame 31 as a first member connected to the support member 2 and forming a first cylinder chamber 71, a second frame 32 as a second member connected to the foot member 4 and forming a second cylinder chamber 81, and a spacer 33 as a length adjustment member provided between the first frame 31 and the second frame 32, with connecting passages 55, 56 formed therein, allowing the length of the lower leg member 3 to be adjusted.

[0104] In this configuration, the spacer 33 is provided only with connecting passages 55 and 56, and no other cylinder chambers or the like are provided, so the vertical length can be easily adjusted. This makes it possible to match the length of the user's left and right legs.

[0105] Furthermore, the communication passage has a first communication passage 55 equipped with a switching valve 90, and a second communication passage 56 equipped with a check valve 95 that allows only the flow of liquid from the tank 58 toward the communication passage. The tank 58 is in communication with the first communication passage 55 via the switching valve 90 and with the second communication passage 56 via the check valve 95 at its lower bottom.

[0106] In this configuration, even though the switching valve 90 allows liquid to flow between the first communication passage 55 and the tank 58 through a throttle, the presence of the second communication passage 56 and the check valve 95 ensures that liquid is quickly supplied from the tank 58 to the first cylinder chamber 71 and the second cylinder chamber 81. This prevents the first cylinder chamber 71 and the second cylinder chamber 81 from becoming negatively pressurized. Furthermore, since the tank 58 communicates with the first communication passage 55 and the second communication passage 56 at its lower bottom, it prevents gas from mixing with the liquid supplied to the first cylinder chamber 71 and the second cylinder chamber 81.

[0107] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0108] For example, the first link 72 of the first hydraulic cylinder 7 may be positioned in front of the first pivot axis 51 in the support member 2, and the second link 82 of the second hydraulic cylinder 8 may be positioned behind the second pivot axis 61 in the foot member 4. In this case, when the lower leg member 3 rotates in the flexion direction, the first hydraulic cylinder 7 extends, and when the lower leg member 3 rotates in the extension direction, the first hydraulic cylinder 7 contracts. Also, when the second hydraulic cylinder 8 extends, the foot member 4 rotates in the dorsiflexion direction, and when the second hydraulic cylinder 8 contracts, the foot member 4 rotates in the plantarflexion direction.

[0109] Furthermore, the movement assistance device is not limited to the hydraulic prosthesis 1, but may also be a power assist device used by users with weak leg strength, such as disabled people or the elderly. The power assist device may also be used by able-bodied individuals to reduce the load on walking. In this case, the support member 2 is provided along the user's thigh and attached to the thigh from the outside, the lower leg member 3 is provided along the user's lower leg and attached to the lower leg from the outside, and the foot member 4 is provided along the user's foot and attached to the foot from the outside. This allows the user's walking motion to be assisted in a natural way.

[0110] Furthermore, the hydraulic circuit 100 of this embodiment can also be applied to a power assist device that assists the user's arm movements, rather than assisting the user's walking movements. In this case, a member corresponding to the support member 2 is provided along the user's upper arm and attached to the upper arm from the outside, a member corresponding to the lower leg member 3 is provided along the user's forearm and attached to the forearm from the outside, and a member corresponding to the foot member 4 is provided along the user's hand and attached to the hand from the outside. [Explanation of Symbols]

[0111] 1...Hydraulic prosthesis (movement assistance device), 2...Support member, 3...Lower leg member, 4...Foot member, 7...First hydraulic cylinder (first hydraulic cylinder), 8...Second hydraulic cylinder (second hydraulic cylinder), 31...First member (first frame), 32...Second member (second frame), 33...Spacer (length adjustment member), 40...Operating unit, 55...First connecting passage (connecting passage), 56...Second connecting passage (connecting passage), 58...Tank, 71...First cylinder chamber, 71a...First pressure chamber, 72...First Link 1, 73...First piston, 81...Second cylinder chamber, 81a...Second pressure chamber, 82...Second link, 83...Second piston, 90...Switching valve, 90A...Shut-off position, 90B...Communication position, 90C...First throttle position (throttling position), 90D...Second throttle position (throttling position), 90E...Third throttle position (throttling position), 92...Poppet (valve body), 92g...First throttle section (throttling section), 92h...Second throttle section (throttling section), 92i...Third throttle section (throttling section), 95...Check valve

Claims

1. A support member attached to the user's thigh is rotatably connected to a lower leg member, and a foot member that touches the ground is rotatably connected to a lower leg member, A first hydraulic cylinder that extends and retracts when the support member rotates relative to the lower leg member, The system includes a second hydraulic cylinder for rotating the aforementioned leg member, The first hydraulic cylinder has a first cylinder chamber formed within the lower leg member, The second hydraulic cylinder has a second cylinder chamber formed within the lower leg member, An operating assist device characterized in that a communication passage connecting the first cylinder chamber and the second cylinder chamber is formed within the lower leg member.

2. An operating assist device according to claim 1, The first hydraulic cylinder is A first piston is slidably inserted into the first cylinder chamber, A first link is rotatably connected to the first piston and the support member, The first cylinder chamber is further partitioned by the first piston and has a first pressure chamber from which liquid is discharged when the first hydraulic cylinder contracts. The second hydraulic cylinder is A second piston is slidably inserted into the second cylinder chamber, A second link is rotatably connected to the second piston and the foot member, The device further comprises a second pressure chamber, which is partitioned within the second cylinder chamber by the second piston and from which liquid is discharged when the second hydraulic cylinder contracts, The aforementioned communication passage is characterized by connecting the first pressure chamber and the second pressure chamber.

3. An operating assist device according to claim 1 or 2, A tank is formed within the lower leg member, which is a space for storing the liquid supplied to and discharged from the first cylinder chamber and the second cylinder chamber. The operation assist device is characterized in that the tank communicates with the communication passage at the bottom, which is a place that is always covered by liquid even if the liquid level inside the tank fluctuates.

4. An operating assist device according to claim 3, The communication passage is further provided with a switching valve that switches the flow of liquid between the communication passage and the tank, The switching valve has a shut-off position that blocks the flow of liquid from the communication passage toward the tank, and a communication position that allows the flow of liquid from the communication passage toward the tank. The aforementioned communication position consists of a plurality of throttling positions in which the amount of liquid throttling differs from one another. The operation assist device is characterized in that the switching valve is provided with a valve body in which a plurality of throttling portions corresponding to the plurality of throttling positions are formed continuously in the axial direction.

5. An operating assist device according to claim 4, It also includes an externally operable control panel, An operating assist device characterized in that the throttle position of the switching valve is selected by operating the operating unit.

6. An operating assist device according to claim 1 or 2, An operating assist device characterized in that the volume of the second hydraulic cylinder is larger than the volume of the first hydraulic cylinder.

7. An operating assist device according to claim 1 or 2, The lower leg member is characterized by comprising a first member connected to the support member and having the first cylinder chamber formed therein, a second member connected to the foot member and having the second cylinder chamber formed therein, and a length adjustment member provided between the first member and the second member and having the connecting passage formed therein, which allows the length of the lower leg member to be adjusted.

8. An operating assist device according to claim 4, The communication passage comprises a first communication passage in which the switching valve is provided, and a second communication passage in which a check valve is provided that allows only the flow of liquid from the tank toward the communication passage. The tank is characterized in that, at the bottom, which is always covered by liquid even when the liquid level inside the tank fluctuates, it communicates with the first communication passage via the switching valve and with the second communication passage via the check valve.

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