JP7733982B2 - Coupling Device - Google Patents

Description

The present invention relates to a coupling device.

Conventionally, joint devices used at the joint connecting two components include an extension device that can change the angle between the two components. One example of such a joint device is a prosthetic leg used at the knee joint. Patent Document 1 describes a method in which a sensor is installed in the femoral socket of a prosthetic leg attached to the stump of an amputated leg to detect the contraction movement of the muscles in the stump of the amputated leg, and the detection information from the sensor is used to control the throttle of a variable valve in a hydraulic cylinder that adjusts the resistance of flexion and extension of the knee joint.

Japanese Patent Application Publication No. 11-19105

However, while the prosthetic limb described in Patent Document 1 was able to generate resistance to flexion or extension, it was not able to flex or extend the knee joint.

The present invention provides a joint device that can bend or extend a joint and generate resistance when the joint is extended or bent.

The present invention provides
A first member;
A second member;
a connecting portion that connects the first member and the second member so as to change the angle between the first member and the second member;
A joint device including an extension and contraction device that can change the angle formed between the first member and the second member by extending and contracting,
The telescopic device is
A power source and
a power transmission unit that transmits power from the power source,
The power transmission unit is
a power transmission path that transmits the power of the power source;
a damping unit that is connected to the power transmission path and damps the movement of the power transmission path ,
The power source generates rotational power,
The damping section is a rotary damper that is configured to damp the rotational power transmitted to the power transmission path, and includes a damper body and a rotary shaft, and is configured to provide a predetermined rotational resistance to the relative rotation between the damper body and the rotary shaft .

According to the present invention, the connecting portion can be bent or extended using a power source, and the damping portion can generate resistance when the connecting portion is extended or bent.

1 is a perspective view of an electric prosthetic leg 1 according to a first embodiment of the present invention, as viewed obliquely from the front. FIG. FIG. 2 is a perspective view of the electric prosthetic leg 1 of FIG. 1 as seen obliquely from behind. FIG. 2 is a diagram showing the internal structure of the electric prosthetic leg 1 of FIG. 1. FIG. 2 is an enlarged view of a power transmission section of the electric prosthetic leg 1 of FIG. 1. 5 is a diagram illustrating power transmission in the power transmission unit of FIG. 4 when the power transmission unit is in a first speed change state. FIG. 5 is a diagram illustrating power transmission in the power transmission unit of FIG. 4 when the power transmission unit is in a second speed change state. FIG. 5 is a diagram illustrating power transmission in the power transmission unit of FIG. 4 when the power transmission unit is in a free state. FIG. 10A and 10B are diagrams illustrating the power that extends the knee joint mechanism 30 from a bent state when climbing stairs. 10A and 10B are diagrams illustrating the power required to bend the knee joint mechanism 30 from an extended state when climbing stairs. FIG. 10 is a perspective view of a power transmission section of an electric prosthetic leg 1 according to a second embodiment of the present invention. FIG. 9 is a cross-sectional view of the power transmission portion of FIG. 8 . FIG. 2 is an exploded perspective view of the damping unit 100 and the damping operating unit 200 common to the electric prosthetic leg 1 of each embodiment of the present invention. 1A to 1E are diagrams showing the movement of the electric prosthetic leg 1 when walking on flat ground. FIG. 12 is a side view of the electric prosthetic leg 1 in the state of FIG. 11(A).

Embodiments of an electric prosthetic leg, which is an example of a joint device of the present invention, will be described below with reference to the drawings. In the following description, the front-to-back, left-to-right, and up-to-down directions will be defined based on the user of the electric prosthetic leg. In the drawings, the front of the electric prosthetic leg is indicated as Fr, the rear as Rr, the left side as L, the right side as R, the top as U, and the bottom as D.

First Embodiment
[Electric prosthetic limb]
As shown in Figures 1 to 3, the electric prosthetic leg 1 of this embodiment is a prosthetic leg for people without knees, and comprises a below-knee member 10 located below the knee, an above-knee member 20 located above the knee, a knee joint mechanism 30 that connects the below-knee member 10 and the above-knee member 20 so that the angle between them can be changed, and an extension/retraction device 40 that can change the angle between the below-knee member 10 and the above-knee member 20 by extending and retracting.

The above-knee component 20 has an upper wall 22 equipped with an adapter 21 that connects to a socket (not shown), and a pair of upper side walls 23 that extend downward from both the left and right ends of the upper wall 22. When viewed from the front to back, it has a roughly U-shaped configuration that opens downward.

The knee-below component 10 comprises a lower wall 12 on which the leg 11 is mounted, and a pair of lower side walls 13 extending upward from both the left and right ends of the lower wall 12. When viewed from the front-to-back direction, it has a generally U-shaped configuration that opens upward.

A pair of lower side walls 13 of the below-knee member 10 are rotatably connected between a pair of upper side walls 23 of the above-knee member 20 around the pivot 35. This mechanism allows the angle between the below-knee member 10 and the above-knee member 20 to be changed, thereby forming the knee joint mechanism 30.

An extension device 40 is provided in the space formed between the above-knee member 20 and the below-knee member 10, allowing the angle formed between the below-knee member 10 and the above-knee member 20 to be changed.

Referring also to FIG. 4, the telescoping device 40 comprises a motor M that outputs rotational power and a power transmission unit that transmits the power of the motor M. The power transmission unit comprises a transmission T, a first spindle unit SP1 that is connected to the transmission T so that power can be transmitted and that converts the rotational power output from the transmission T into translational motion, a disconnecting mechanism 50 that is interposed between the motor M and the first and second speed change mechanisms T1 and T2 of the transmission T, which will be described later, and a second spindle unit SP2 that converts the rotational power output from the motor M into translational motion of the actuator 55 of the disconnecting mechanism 50. Note that if power transmission members such as gears are provided downstream of the first spindle unit SP1 from the motor M, these power transmission members are also included in the power transmission unit, and all of the power transmission members constitute the power transmission path.

The transmission T is equipped with a transmission case 60 that has a rectangular shape when viewed from the front-to-rear direction and includes a top plate 61, a bottom plate 62, and a pair of side plates 63 connecting the left and right ends of the top plate 61 and bottom plate 62. The transmission case 60 has a pair of rotating wings 64 extending downward from the bottom plate 62, which are supported by a rotating support wall 14 extending upward from the lower wall 12 of the knee-below member 10 so as to be able to swing but not move about a lower swing part 70.

The motor M is positioned above and in front of the top plate 61 of the transmission case 60 so that the output shaft 71 passes through the top plate 61 and protrudes into the interior of the transmission case 60. The first spindle unit SP1 is positioned on the opposite side of the motor M in the front-to-rear direction, sandwiching the interrupter mechanism 50 therebetween. In other words, the motor M is positioned forward of the interrupter mechanism 50 in the front-to-rear direction, and the first spindle unit SP1 is positioned rearward of the interrupter mechanism 50 in the front-to-rear direction. This makes it possible to prevent the electric prosthetic leg 1 from becoming larger in the width direction while maintaining balance in the front-to-rear direction, even when the motor M is mounted on the electric prosthetic leg 1.

The second spindle unit SP2, which converts the rotational power output from the motor M into translational motion of the actuator 55 of the interrupter mechanism 50, is positioned between the motor M and the first spindle unit SP1 in the front-to-rear direction. The output shaft 71 of the motor M, the first spindle 73 of the first spindle unit SP1, and the second spindle 75 of the second spindle unit SP2 are positioned parallel to one another and face up and down when the knee joint mechanism 30 is fully extended.

The first spindle unit SP1 has a first spindle 73 formed with a male thread 73a and a sleeve 74 formed with a female thread 74a. Rotation of the first spindle 73 causes the sleeve 74 to translate along the axis of the first spindle 73. In this embodiment, the first spindle 73 receives rotational power from the motor M transmitted by the transmission T to perform rotational motion. Meanwhile, the sleeve 74 is immovably attached to a pair of inner side walls 24 extending downward from the upper wall 22 of the above-knee member 20, pivoting about the upper pivot portion 25. Therefore, when the first spindle 73 rotates to one side (in the direction of arrow D1 in FIG. 5A) in response to the rotational power of the motor M transmitted by the transmission T, the sleeve 74 translates away from the transmission T. When the first spindle 73 rotates to the other side (in the direction of arrow D2 in FIG. 5B), the sleeve 74 translates toward the transmission T.

In other words, the distance between the sleeve 74 and the transmission T expands or contracts depending on the rotation direction of the first spindle 73. Because the sleeve 74 is immovably attached to the above-knee member 20 as described above, the distance between the sleeve 74 and the transmission T expands or contracts depending on the rotation direction of the first spindle 73, causing the below-knee member 10, to which the transmission T is attached, and the above-knee member 20, to which the sleeve 74 is attached, to rotate around the pivot 35. This changes the angle formed between the above-knee member 20 and the below-knee member 10.

As shown in FIG. 4, the transmission T includes an output gear 72 provided on the output shaft 71 of the motor M, an input gear 77 provided approximately in the center of the second spindle 75 of the second spindle unit SP2 and meshing with the output gear 72, a first transmission mechanism T1, and a second transmission mechanism T2.

The first transmission mechanism T1 is composed of a first drive gear 78 that is immovably mounted above the second spindle 75 of the second spindle unit SP2, and a first driven gear 79 that is mounted on the first spindle 73 of the first spindle unit SP1 so as to rotate integrally with the first spindle 73 and that meshes with the first drive gear 78.

The second transmission mechanism T2 is composed of a second drive gear 80 that is immovably mounted below the second spindle 75 of the second spindle unit SP2, and a second driven gear 81 that is mounted on the first spindle 73 of the first spindle unit SP1 so as to rotate integrally with the first spindle 73 and that meshes with the second drive gear 80.

The first transmission mechanism T1 transmits the power of the motor M at a first transmission ratio. The second transmission mechanism T2 transmits the power of the motor M at a second transmission ratio different from the first transmission ratio. By providing two power transmission paths with different transmission ratios, it is possible to switch the movement speed and generated power of the extension and flexion in the knee joint mechanism 30. As long as the first transmission ratio and the second transmission ratio are different, either the first transmission mechanism T1 or the second transmission mechanism T2 may be a speed-reduction mechanism and the other a speed-up mechanism, or one may be a constant speed mechanism and the other a speed-reduction or speed-up mechanism, or both may be speed-reduction mechanisms, or both may be speed-up mechanisms.

When the first gear ratio is defined as the ratio of the post-shift rotation speed, which is the rotation speed on the anti-motor M side (first spindle unit SP1 side) of the first transmission mechanism T1, to the pre-shift rotation speed, which is the rotation speed on the motor M side of the first transmission mechanism T1, and the second gear ratio is defined as the ratio of the post-shift rotation speed, which is the rotation speed on the anti-motor M side (first spindle unit SP1 side) of the second transmission mechanism T2, to the pre-shift rotation speed, which is the rotation speed on the motor M side of the second transmission mechanism T2, it is preferable that the first gear ratio be configured to be smaller than the second gear ratio.

For example, when the first speed change ratio of the first transmission mechanism T1 is less than 1, the rotation speed on the side opposite the motor M (the side opposite the first spindle unit SP1) decreases compared to the rotation speed on the motor M side, resulting in an increase in torque. When the second speed change ratio of the second transmission mechanism T2 is greater than 1, the rotation speed on the side opposite the motor M (the side opposite the first spindle unit SP1) increases compared to the rotation speed on the motor M side, resulting in a decrease in torque. In this case, the first drive gear 78 has a smaller diameter than the second drive gear 80, allowing the first drive gear 78 and the motor M to be positioned closer to each other. In this embodiment, the first transmission mechanism T1 is positioned closer to the motor M than the second transmission mechanism T2. More specifically, the motor M is positioned forward of the first drive gear 78 so as to overlap the first drive gear 78 in the vertical direction.

The first transmission mechanism T1 and the second transmission mechanism T2 are switched by the interrupting mechanism 50. The interrupting mechanism 50 includes an upper clutch 50U interposed between the motor M and the first transmission mechanism T1, a lower clutch 50D interposed between the motor M and the second transmission mechanism T2, and an actuator 55 that rotates integrally with the input gear 77.

The upper clutch 50U is a mesh clutch that includes a first engaging element 51 on the motor M side and a second engaging element 52 on the first transmission mechanism T1 side. More specifically, the first engaging element 51 is provided above the actuator 55 and input gear 77 so as to rotate integrally with the input gear 77. The second engaging element 52 is provided below the first drive gear 78 so as to be engageable with the first engaging element 51 and rotate integrally with the first drive gear 78. The second engaging element 52 and first drive gear 78 are attached above the second spindle 75 of the second spindle unit SP2 so as to be rotatable but immovable relative to the second spindle 75.

The lower clutch 50D is a mesh clutch that includes a third engaging element 53 on the motor M side and a fourth engaging element 54 on the second transmission mechanism T2 side. More specifically, the third engaging element 53 is provided below the actuator 55 and input gear 77 so as to rotate integrally with the input gear 77. The fourth engaging element 54 is provided above the second drive gear 80 so as to be engageable with the third engaging element 53 and to rotate integrally with the second drive gear 80. The fourth engaging element 54 and second drive gear 80 are attached below the second spindle 75 of the second spindle unit SP2 so as to be rotatable but immovable relative to the second spindle 75.

As described above, the actuator 55 is attached to the input gear 77 so as to rotate integrally with it, and the first engaging element 51 and third engaging element 53 are attached to the upper and lower parts of the actuator 55 so as to rotate integrally with it. The actuator 55 is mounted approximately in the center of the second spindle 75, i.e., between the first drive gear 78 and the second drive gear 80 in the vertical direction. Here, the actuator 55 is the screw nut 76 of the second spindle unit SP2. The second spindle unit SP2 has a second spindle 75 with an external thread and a screw nut 76 (actuator 55) with an internal thread. As the input gear 77 rotates, the screw nut 76 (actuator 55) moves in translation while rotating along the axis of the second spindle 75.

When the motor M rotates in a first direction (the direction of arrow D1 in Figure 5A), the screw nut 76 (actuator 55) moves upward in the vertical direction, which is the direction of translational motion, and when the motor M rotates in a second direction (the direction of arrow D2 in Figure 5B), which is opposite the first direction, the screw nut 76 (actuator 55) moves downward in the vertical direction. In this way, the direction of movement of the actuator 55 can be changed by changing the direction of rotation of the motor M.

The interrupter mechanism 50 can be in three states: a first speed change state, a second speed change state, and a free state, as the actuator 55 translates along the axis of the second spindle 75.

In the first speed change state, as shown in FIG. 5A, the motor M rotates in the first direction (the direction of arrow D1 in FIG. 5A), and the screw nut 76 (actuator 55) moves upward, causing the first engaging element 51 and the second engaging element 52 to be connected and the third engaging element 53 and the fourth engaging element 54 to be disconnected. In other words, the upper clutch 50U is engaged and the lower clutch 50D is disengaged. In the first speed change state, the power of the motor M is transmitted to the output gear 72, input gear 77, actuator 55, first engaging element 51, second engaging element 52, first drive gear 78, first driven gear 79, and first spindle unit SP1.

In the second speed change state, as shown in FIG. 5B, the motor M rotates in the second direction (the direction of arrow D2 in FIG. 5B) and the screw nut 76 (actuator 55) moves downward, disengaging the first and second engagers 51 and 52 and connecting the third and fourth engagers 53 and 54. In other words, the upper clutch 50U is disengaged and the lower clutch 50D is engaged. In the second speed change state, the power of the motor M is transmitted to the output gear 72, input gear 77, actuator 55, third engager 53, fourth engager 54, second drive gear 80, second driven gear 81, and first spindle unit SP1.

In the free state, as shown in FIG. 5C, the first engaging element 51 and the second engaging element 52 are disengaged, and the third engaging element 53 and the fourth engaging element 54 are disengaged. In other words, the upper clutch 50U is disengaged, and the lower clutch 50D is disengaged. In the free state, the motor M is stopped, and the rotation of the first spindle unit SP1 rotates the first driven gear 79 and the second driven gear 81. However, the rotation of the first spindle unit SP1 is transmitted to the first driven gear 79, the first drive gear 78, and the second engaging element 52, but not to the first engaging element 51. Similarly, the rotation of the first spindle unit SP1 is transmitted to the second driven gear 81, the second drive gear 80, and the fourth engaging element 54, but not to the third engaging element 53.

In Figures 4 to 5C, the symbol D denotes a rotary damper that provides appropriate resistance to the second spindle 75 of the second spindle unit SP2 to ensure translational movement of the screw nut 76 (operator 55) when the motor M rotates. The rotary damper D is composed of a first damper gear 86 that is attached to the rotary shaft of the rotary damper D, and a second damper gear 87 that is attached to the second spindle 75 of the second spindle unit SP2 so as to rotate integrally with the second spindle 75 and that meshes with the first damper gear 86. The rotary damper D is located above and in front of the bottom plate portion 62 of the transmission case 60, and below the motor M.

With the electrically powered prosthetic leg 1 configured in this way, it is possible to smoothly ascend stairs, whereas with conventional passive prosthetic legs equipped with passive dampers, the user had to ascend one step at a time with the non-prosthetic leg.

Specifically, as shown in Figure 6, when the electric prosthetic leg 1 is extended forward to climb stairs and a load is applied to the electric prosthetic leg 1, a large amount of power is required to extend the knee joint mechanism 30 from a bent position.

At this time, as shown in FIG. 5A, by rotating the motor M in the first direction (the direction of arrow D1 in FIG. 5A), the power of the motor M is transmitted from the output gear 72 to the input gear 77. By rotating the input gear 77 in the second direction (the direction of arrow D2 in FIG. 5A), the actuator 55 rotates around the second spindle 75 of the second spindle unit SP2 and moves upward while being guided by the second spindle 75. Then, the first engaging element 51 provided above the actuator 55 and input gear 77 engages with the second engaging element 52 provided below the first drive gear 78, and the interrupting mechanism 50 enters the first speed change state.

When the interrupter mechanism 50 is in the first speed change state, the power of the motor M is transmitted to the output gear 72, input gear 77, actuator 55, first engager 51, second engager 52, first drive gear 78, first driven gear 79, and first spindle unit SP1. The rotation of the first drive gear 78 together with the input gear 77 in the second direction (the direction of arrow D2 in FIG. 5A) causes the first driven gear 79 to rotate in the first direction (the direction of arrow D1 in FIG. 5A), and the rotation of the first driven gear 79 in the first direction (the direction of arrow D1 in FIG. 5A) causes the first spindle 73 of the first spindle unit SP1 to rotate in the first direction (the direction of arrow D1 in FIG. 5A). As a result, the sleeve 74 moves in translation away from the transmission T, and the above-knee member 20 to which the sleeve 74 is attached rotates around the rotating part 35 relative to the below-knee member 10 to which the transmission T is attached, thereby extending the knee joint mechanism 30.

On the other hand, to smoothly ascend stairs, the knee joint mechanism 30 needs to be bent (lifted) from an extended position while weight is being applied to the healthy leg, as shown in Figure 7. Bending the knee joint mechanism 30 from an extended position does not require a large amount of power, but requires a quick movement.

At this time, as shown in FIG. 5B, by rotating the motor M in the second direction (the direction of arrow D2 in FIG. 5B), the power of the motor M is transmitted from the output gear 72 to the input gear 77. As the input gear 77 rotates in the first direction (the direction of arrow D1 in FIG. 5B), the actuator 55 rotates around the second spindle 75 of the second spindle unit SP2 and moves downward, guided by the second spindle 75. Then, the third engaging element 53 provided below the actuator 55 and input gear 77 engages with the fourth engaging element 54 provided above the second drive gear 80, and the interrupting mechanism 50 enters the second speed change state.

When the interrupter mechanism 50 is in the second speed change state, the power of the motor M is transmitted to the output gear 72, input gear 77, actuator 55, third engager 53, fourth engager 54, second drive gear 80, second driven gear 81, and first spindle unit SP1. As the second drive gear 80 rotates together with the input gear 77 in the first direction (the direction of arrow D1 in Figure 5B), the second driven gear 81 rotates in the second direction (the direction of arrow D2 in Figure 5B), and as the second driven gear 81 rotates in the second direction (the direction of arrow D2 in Figure 5B), the first spindle 73 of the first spindle unit SP1 rotates in the second direction (the direction of arrow D2 in Figure 5B). As a result, the sleeve 74 moves in translation closer to the transmission T, and the below-knee member 10, to which the transmission T is attached, rotates around the rotating part 35 relative to the above-knee member 20, to which the sleeve 74 is attached, thereby bending the knee joint mechanism 30.

When descending stairs or walking on flat ground, motor M is stopped because power is not required.

However, if an external load is applied to the electric prosthetic leg 1 while the motor M is stopped, the knee joint mechanism 30 in its extended position may be unable to withstand the load and may bend, resulting in so-called knee bending. Therefore, the electric prosthetic leg 1 is provided with a damping unit 100 and a damping actuator 200 to prevent knee bending when descending stairs or walking on level ground. Details of the damping unit 100 and the damping actuator 200 will be described later.

In the electric prosthetic leg 1 configured in this manner, the knee joint mechanism 30 can be extended and flexed via the transmission T, which transmits the power of the motor M. The rotation range of the knee joint mechanism 30 is limited to 180° or less; when the knee joint mechanism 30 is extended, the angle between the below-knee member 10 and the above-knee member 20 is approximately 180°, and when the knee joint mechanism 30 is flexed, this angle is less than 180°.

The transmission T has two power transmission paths with different gear ratios, making it possible to switch between the extension and flexion movement speeds and generated power of the knee joint mechanism 30. In particular, when climbing stairs, the required movement speed and generated power differ between flexion and extension of the knee joint mechanism 30, and the power transmission path can be changed between flexion and extension of the knee joint mechanism 30.

In addition, the interrupting mechanism 50 interposed between the motor M and the transmission T has an upper clutch 50U interposed between the motor M and the first transmission mechanism T1, and a lower clutch 50D interposed between the motor M and the second transmission mechanism T2, allowing appropriate switching between the two power transmission paths.

In particular, the telescopic device 40 is equipped with a second spindle unit SP2 that converts the rotational power output from the motor M into translational motion of the actuator 55, allowing a single motor M to control the actuator 55 and the extension and flexion of the knee joint mechanism 30. Furthermore, the single actuator 55 is configured to be able to switch the transmission T between the first speed change state, the second speed change state, and a free state, preventing two power transmission paths from being connected simultaneously.

Furthermore, when the knee joint mechanism 30 is extended and the electric prosthetic leg 1 is viewed along the rotation axis of the rotating unit 35 of the knee joint mechanism 30, the region where the angle between the below-knee member 10 and the above-knee member 20 is less than 180° (the region behind (calf) side of the line connecting the rotating unit 35 and the lower swinging unit 70 in Figure 3) is called the narrow-angle region, and the region where the angle is 180° or more (the region ahead (shin) side of the line connecting the rotating unit 35 and the lower swinging unit 70 in Figure 3) is called the wide-angle region. The first spindle unit SP1 is positioned in the narrow-angle region. On the other hand, the motor M is positioned in the wide-angle region. By positioning the first spindle unit SP1 in the narrow-angle region and the motor M in the wide-angle region in this way, the first spindle unit SP1 and the motor M can be positioned in a balanced manner, sandwiching the rotating unit 35 of the knee joint mechanism 30. Furthermore, the transmission T and the interrupting mechanism 50 are disposed between the motor M and the first spindle unit SP1. Therefore, the motor M, transmission T, interrupting mechanism 50, and first spindle unit SP1 can be disposed together.

Second Embodiment
The electric prosthetic leg 1 of the second embodiment differs from the electric prosthetic leg 1 of the first embodiment in the configuration of the extension device 40. More specifically, in the extension device 40 of the first embodiment, the translational motion of the actuator 55 is realized by converting the rotational power output from the motor M by the second spindle unit SP2. In contrast, in the extension device 40 of the second embodiment, the translational motion of the actuator 55 is realized by a clutch actuator ACT, which is a drive source different from the motor M, and a clutch fork 90 that transmits the power of the clutch actuator ACT to the actuator 55. In the following explanation, the extension device 40 of the electric prosthetic leg 1 of the second embodiment will be explained with reference to Figures 8 and 9, but configurations that are the same as or equivalent to those of the extension device 40 of the electric prosthetic leg 1 of the first embodiment will be assigned the same reference numerals in the figures and explanations will be omitted, and only the differences will be explained.

As shown in Figures 8 and 9, the extension/contraction device 40 of the second embodiment comprises a motor M that outputs rotational power, a transmission T that transmits the power of the motor M, a first spindle unit SP1 that is connected to the transmission T so that power can be transmitted and that converts the rotational power output from the transmission T into translational motion, a disconnecting mechanism 50 that is interposed between the motor M and the first and second transmission mechanisms T1 and T2 of the transmission T, a support shaft 95 that is positioned parallel to the output shaft 71 of the motor M and the first spindle 73 of the first spindle unit SP1 and supports the disconnecting mechanism 50, a clutch actuator ACT that performs translational motion, and a clutch fork 90 that transmits the power of the clutch actuator ACT to the actuator 55 of the disconnecting mechanism 50.

The clutch actuator ACT is a power source different from the motor M, and performs translational motion along the axial direction (up and down direction) of the support shaft 95, as shown by arrow Y1 in Figure 8.

One end of the clutch fork 90 is connected to the clutch actuator ACT, and the middle portion is supported by the pivot shaft 65, allowing it to pivot freely around the pivot shaft 65, as shown by arrow Y2 in Figure 8. The other end of the clutch fork 90 is provided with arms 92 that branch off from a branch portion 91 located on the opposite side of the pivot shaft 65 from the clutch actuator ACT, and extend in opposite arc-shaped directions. A connecting pin 93 that engages with the slide clutch 56, described below, is provided at the tip of each arm 92. Therefore, when the clutch actuator ACT performs translational motion, the clutch fork 90 pivots around the pivot shaft 65, causing the connecting pin 93 of the clutch fork 90 to pivot up and down.

The transmission T includes an output gear 72 mounted on the output shaft 71 of the motor M, a first input gear 77A and a second input gear 77B mounted approximately in the center of the support shaft 95 and meshing with the output gear 72, a first transmission mechanism T1, and a second transmission mechanism T2. The first input gear 77A and the second input gear 77B constitute the input gear 77.

The first transmission mechanism T1 is composed of a first drive gear 78 that is immovably mounted on the upper side of the support shaft 95, and a first driven gear 79 that is mounted on the first spindle 73 of the first spindle unit SP1 so as to rotate integrally with the first spindle 73 and that meshes with the first drive gear 78.

The second transmission mechanism T2 is composed of a second drive gear 80 that is immovably mounted below the support shaft 95, and a second driven gear 81 that is mounted on the first spindle 73 of the first spindle unit SP1 so as to rotate integrally with the first spindle 73 and that meshes with the second drive gear 80.

The gear ratios of the first and second transmission mechanisms T1 and T2 are the same as those in the first embodiment, so a description thereof will be omitted here. The first and second transmission mechanisms T1 and T2 are switched by an interrupting mechanism 50. The interrupting mechanism 50 includes an upper clutch 50U interposed between the motor M and the first transmission mechanism T1, a lower clutch 50D interposed between the motor M and the second transmission mechanism T2, and an actuator 55.

The upper clutch 50U is a mesh clutch that includes a first engaging element 51 on the motor M side and a second engaging element 52 on the first transmission mechanism T1 side. More specifically, the first engaging element 51 is provided above the first input gear 77A so as to rotate integrally with the first input gear 77A. The second engaging element 52 is provided below the first drive gear 78 so as to be engageable with the first engaging element 51 and to rotate integrally with the first drive gear 78. The second engaging element 52 and first drive gear 78 are attached above the support shaft 95 so as to be rotatable but immovable relative to the support shaft 95.

The lower clutch 50D is a mesh clutch that includes a third engaging element 53 that is an engaging element on the motor M side, and a fourth engaging element 54 that is an engaging element on the second transmission mechanism T2 side. More specifically, the third engaging element 53 is provided below the second input gear 77B so as to rotate integrally with the second input gear 77B. The fourth engaging element 54 is provided above the second drive gear 80 so as to be engageable with the third engaging element 53 and to rotate integrally with the second drive gear 80. The fourth engaging element 54 and second drive gear 80 are attached below the support shaft 95 so as to be rotatable but immovable relative to the support shaft 95.

The actuator 55 includes an annular slide clutch 56 that is constantly engaged with the connecting pin 93 of the clutch fork 90, and a bearing 57 that performs translational motion together with the slide clutch 56. The actuator 55 is positioned vertically between the first input gear 77A and the second input gear 77B.

The slide clutch 56 has a connecting hole that engages with the connecting pin 93 of the clutch fork 90. The connecting hole absorbs the oscillation of the clutch fork 90 and converts it into vertical translational movement of the slide clutch 56.

The bearing 57 comprises an outer ring 57a supported non-rotatably by the slide clutch 56, an inner ring 57b configured to rotate integrally with the first input gear 77A provided with the first engaging element 51 and the second input gear 77B provided with the third engaging element 53, and a rolling element 57c disposed between the outer ring 57a and the inner ring 57b, allowing relative rotation between the outer ring 57a and the inner ring 57b.

The inner ring 57b, together with the first input gear 77A and the second input gear 77B, is supported on the outer periphery of a support flange 96 that is key-connected to a support shaft 95 so as to be able to translate vertically.

The slide clutch 56 and bearing 57 (actuator 55) move upward along the support shaft 95 when one end of the clutch fork 90 moves downward due to the clutch actuator ACT, and move downward along the support shaft 95 when one end of the clutch fork 90 moves upward due to the clutch actuator ACT. A predetermined vertical gap is provided between the slide clutch 56 and outer ring 57a and the first input gear 77A, so that the first input gear 77A does not interfere with the slide clutch 56 and outer ring 57a, which are non-rotating members. Similarly, a predetermined vertical gap is provided between the slide clutch 56 and outer ring 57a and the second input gear 77B, so that the second input gear 77B does not interfere with the slide clutch 56 and outer ring 57a, which are non-rotating members.

The interrupter mechanism 50 can be in three states: a first speed change state, a second speed change state, and a free state, as the slide clutch 56 and bearing 57 (operator 55) move in a vertical translational motion along the axis of the support shaft 95.

In the first speed change state, the slide clutch 56 and bearing 57 (operator 55) move upward, so that the first engager 51 and second engager 52 are connected and the third engager 53 and fourth engager 54 are disconnected, as in FIG. 5A. In other words, the upper clutch 50U is engaged and the lower clutch 50D is disengaged. In the first speed change state, the power of the motor M is transmitted to the output gear 72, the first input gear 77A (inner ring 57b and second input gear 77B), the first engager 51, the second engager 52, the first drive gear 78, the first driven gear 79, and the first spindle unit SP1.

In the second speed change state, the slide clutch 56 and bearing 57 (operator 55) move downward, disengaging the first and second engagers 51 and 52 and engaging the third and fourth engagers 53 and 54, as in FIG. 5B. In other words, the upper clutch 50U is disengaged and the lower clutch 50D is engaged. In the second speed change state, the power of the motor M is transmitted to the output gear 72, the second input gear 77B (inner ring 57b and first input gear 77A), the third engager 53, the fourth engager 54, the second drive gear 80, the second driven gear 81, and the first spindle unit SP1.

In the free state, as in FIG. 5C, the first engaging element 51 and the second engaging element 52 are disengaged, and the third engaging element 53 and the fourth engaging element 54 are disengaged. In other words, the upper clutch 50U is disengaged, and the lower clutch 50D is disengaged. In the free state, the motor M is stopped, and the rotation of the first spindle unit SP1 rotates the first driven gear 79 and the second driven gear 81. However, the rotation of the first spindle unit SP1 is transmitted to the first driven gear 79, the first drive gear 78, and the second engaging element 52, but not to the first engaging element 51. Similarly, the rotation of the first spindle unit SP1 is transmitted to the second driven gear 81, the second drive gear 80, and the fourth engaging element 54, but not to the third engaging element 53.

In the electric prosthetic leg 1 configured in this manner, as in the first embodiment, the knee joint mechanism 30 can be extended and flexed via the transmission T, which transmits the power of the motor M, and the effects described for the electric prosthetic leg 1 of the first embodiment can be obtained. Furthermore, in the electric prosthetic leg 1 of the second embodiment, the actuator 55 is switched using a clutch actuator ACT, which is a power source different from the motor M used to extend and flex the knee joint mechanism 30, allowing for more stable switching of the actuator 55.

[Damping section and damping operating section]
Next, the damping unit 100 and the damping operation unit 200 provided in the electric prosthetic leg 1 of each embodiment will be described with reference to FIGS. 1 to 4 and 10 to 12.

As shown in Figures 3 and 4, the electric prosthetic leg 1 is equipped with a damping unit 100 that is connected to a power transmission path that transmits the power of the motor M and is capable of damping the movement of the power transmission path, and a damping operation unit 200 that operates the damping unit 100 at a predetermined timing.

3, 4 and 10, the damping unit 100 is rotatably supported on the top plate portion 61 of the transmission T via a bearing 101 and includes a rotary shaft 102 arranged parallel to the first spindle 73, a second gear 104 provided on the outer periphery of the rotary shaft 102 so as to be integrally rotatable therewith and meshing with a first gear 103 that rotates integrally with the first spindle 73, a damper holder 105 provided on the upper end of the rotary shaft 102 so as to be integrally rotatable therewith, a rotary damper 106 including a damper main body 106a held integrally by the damper holder 105 and a rotary shaft 106b protruding upward from the damper main body 106a, and a damping unit 106a that houses the rotary shaft 102, the first gear 103, the second gear 104, the damper holder 105 and the rotary damper 106 and is fixed to the top plate portion 61. The damping section case 120 (shown only in FIG. 4 ), a first clutch member 107 arranged on the upper surface of the damping section case 120 and connected to the rotary shaft 106b so as to be rotatable together with the rotary shaft 106b, a second clutch member 108 arranged above and facing the first clutch member 107, a plurality of guide pins 109 protruding upward from the damping section case 120 and penetrating the flange portion 108a of the second clutch member 108 to support the second clutch member 108 so that it can move up and down but cannot rotate, a plurality of nuts 110 threadedly attached to the upper end of each guide pin 109 to prevent the second clutch member 108 from coming off, and a plurality of springs 111 arranged on the outer periphery of each guide pin 109 to urge the second clutch member 108 in a direction away from the first clutch member 107.

The rotary damper 106 applies a predetermined rotational resistance to the relative rotation between the damper body 106a and the rotary shaft 106b. The damper body 106a of the rotary damper 106 is connected to the first spindle 73 via the damper holder 105, the rotary shaft 102, the second gear 104, and the first gear 103, and the rotary shaft 106b of the rotary damper 106 is connected to the damping unit case 120, which is the fixed part, via a clutch mechanism consisting of the first clutch member 107 and the second clutch member 108.

In the clutch-disengaged state where the first clutch member 107 and the second clutch member 108 are separated, the first clutch member 107 spins freely, so the rotary damper 106 does not operate and the movement of the first spindle 73 is not damped. On the other hand, in the clutch-engaged state where the second clutch member 108 is pressed downward and the first clutch member 107 and the second clutch member 108 are engaged, the rotation of the first clutch member 107 is restricted, so the rotational resistance generated between the damper body 106a and the rotary shaft 106b is transmitted to the first spindle 73 via the damper holder 105, the rotary shaft 102, the second gear 104, and the first gear 103, damping the movement of the first spindle 73.

This type of damping unit 100 can generate mechanical resistance when the knee joint mechanism 30 extends or bends. Furthermore, because the damping unit 100 is connected to a power transmission path that transmits the power of the motor M, it can provide a higher damping function than if it were provided in the knee joint mechanism 30. In other words, because the damping function of the rotary damper 106 is proportional to speed, connecting the rotary damper 106 to a power transmission path that rotates at a higher rotational speed than the knee joint mechanism 30 can effectively utilize the damping function of the rotary damper 106.

In addition, to more effectively utilize the damping function of the rotary damper 106, it is preferable that the ratio of the rotation speed of the second gear 104 to the rotation speed of the first gear 103 be greater than 1. This allows the rotary damper 106 to be connected to the second gear 104, which rotates at a higher rotation speed than the first gear 103, which rotates integrally with the first spindle 73.

Furthermore, when the motor M is located upstream and the rotary damper 106 is connected downstream of the transmission T, as in this embodiment, it is preferable that the transmission T be a speed-increasing mechanism. Conversely, when the motor M is located upstream and the rotary damper 106 is connected upstream of the transmission T (on the motor M side), it is preferable that the transmission T be a speed-reducing mechanism.

In this embodiment, the damping unit 100 is positioned between the motor M and the first spindle unit SP1. This prevents the damping unit 100 from protruding outward.

As shown in FIG. 12, the damping actuation unit 200 mechanically actuates the damping unit 100 by utilizing the moment N generated when the heel H lands during walking. Specifically, as shown in FIGS. 1, 2, and 12, the pair of lower sidewalls 13 of the knee-underside member 10 includes a pair of lower sidewall bodies 13a extending upward from both the left and right ends of the lower wall 12, and a pair of swinging sidewalls 13c connected to the above-knee member 20 via a swing shaft 13b provided at the top and front of the lower sidewall bodies 13a along the left-right direction. The pair of swinging sidewalls 13c are integrally connected via a connecting wall 13d and integrally include an actuation lever 13e (see FIG. 3) located above the second clutch member 108 of the damping unit 100.

As shown in Figure 11, when walking on flat ground while wearing the electric prosthetic leg 1, the electric prosthetic leg 1 receives a reaction force (compressive load) from the ground as an external load from the start of landing as shown in Figure 11(A) to the end of landing as shown in Figure 11(D). In particular, at the start of landing as shown in Figure 11(A), the reaction force received from the ground increases rapidly, which may cause the knee joint mechanism 30 to bend unintentionally, resulting in so-called knee bending. In the electric prosthetic leg 1 of this embodiment, focusing on the heel H landing at the start of landing, the swing axis 13b is positioned forward and away from the imaginary line L1 connecting the heel H and the rotating part 35 of the knee joint mechanism 30, as shown in Figure 12.

In this way, when the heel H lands during walking, a moment N is generated around the pivot axis 13b, causing the pivoting side wall 13c to pivot relative to the lower side wall main body 13a. This causes the operating lever 13e to press down on the second clutch member 108 of the damping unit 100, mechanically operating the damping unit 100. This damps the movement of the knee joint mechanism 30, preventing unintended bending during landing. Furthermore, because a moment is less likely to be generated at the rotating unit 35 located on the imaginary line L1, unintended bending during landing can be more reliably prevented.

Furthermore, as shown in Figure 12, the swing axis 13b is located on or near the imaginary line L2 connecting the toe T and the rotating unit 35 when the toe T lands. In this way, when the toe T lands, no moment N or only a small moment N is generated, and the damping unit 100 does not function. This allows for a transition from state (D) to state (E) in Figure 11, allowing for smooth bending of the knee joint mechanism 30 when the electric prosthetic leg 1 is swung up.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. Those skilled in the art will clearly be able to conceive of various modifications and alterations within the scope of the claims, and it will be understood that these naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention.

For example, in the above embodiment, an electric prosthetic leg was used as an example of one embodiment of the joint device of the present invention, but the invention is not limited to this and may also be applied to the upper limb (arm joint), to animals other than humans, or to robots.

In addition, in the above embodiment, the power of one motor M is transmitted to the first and second speed change mechanisms T1 and T2 via the interrupter mechanism 50, but this is not limited to this. Intermittent mechanisms may also be provided between the two power sources and the first and second speed change mechanisms T1 and T2, respectively.

Furthermore, the on-off mechanism 50 is not limited to a dog clutch, but may be other clutch mechanisms such as a friction clutch or centrifugal clutch, or may be a clutchless mechanism such as a continuous gear ratio change mechanism.

In addition, in the above embodiment, the damping unit 100 is connected to the first spindle 73, but it may also be connected to the transmission T.

In addition, while the above embodiment illustrates a configuration in which the damping force is generated by the damping unit 100 and the damping actuation unit 200, the configuration is not limited to this, and the damping unit 100 may be an electric machine. That is, the damping force may be generated by regeneratively driving the electric machine, or by power driving the electric machine in the reverse direction, i.e., in a direction that reduces the rotational power due to external load, to generate the damping force.

This specification also describes at least the following items. Note that the elements in parentheses correspond to those in the above-mentioned embodiments, but are not limited to these.

(1) a first member (the lower-knee member 10);
a second member (above-knee member 20);
a connecting portion (knee joint mechanism 30) that connects the first member and the second member so as to be able to change the angle between them;
A joint device (electric prosthetic leg 1) including an extension/retraction device (extension device 40) that can change the angle between the first member and the second member by extending and contracting,
The telescopic device is
a power source (motor M);
a power transmission unit that transmits power from the power source,
The power transmission unit is
A coupling device comprising a damping section (damping section 100) that is connected to a power transmission path that transmits the power and that damps the movement of the power transmission path.

According to (1), the connecting portion can be bent or extended by the power source, and the damping portion, which damps the movement of the power transmission path, can generate resistance when the connecting portion is extended or extended.

(2) The coupling device according to (1),
The power source generates rotational power,
The power transmission unit further includes a transmission unit (transmission T) that changes the speed of rotation of the power source,
The damping portion is provided to be connected to the transmission portion.

According to (2), since the damping function is proportional to the speed, the damping function can be improved by providing it in the speed-changing section that changes the rotation speed of the power source rather than providing it in the connecting section.

(3) The coupling device according to (2),
the transmission unit includes a speed increasing mechanism that increases the rotation speed of the power source,
The coupling device is configured so that the damping unit is connected to the power transmission path downstream of the speed change unit when the power source is located upstream.

According to (3), the damping function is proportional to the speed, so by placing it downstream of the speed-increasing mechanism, the damping function can be further improved.

(4) The coupling device according to any one of (1) to (3),
The damping portion is a coupling device disposed between the power source and a member (first spindle 73) that constitutes the power transmission path.

(4) prevents the damping section from protruding outward.

(5) The coupling device according to any one of (1) to (4),
The joint device is a prosthetic leg,
The first member is a coupling device having a swing shaft (swing shaft 13b) that is positioned forward and spaced apart from a virtual line (virtual line L1) that connects the heel (heel H) and the pivoting part (rotating part 35) of the connection part when the heel lands.

According to (5), when the heel lands during walking, the moment around the swing axis can be used to mechanically activate the damping section. This allows the damping function to be generated when the heel lands and a large compressive load acts on the prosthetic leg.

(6) The coupling device according to (5),
The coupling device is configured such that the swing axis is located on or in the vicinity of another imaginary straight line (imaginary straight line L2) that connects the toe and the connecting portion when the toe (toe T) lands.

According to (6), when the toe lands, no moment is generated and the damping section does not function, allowing the knee to bend smoothly when swinging up the prosthetic leg.

1 Electric prosthetic leg 10 Knee-side member (first member)
13b Swing shaft 20 Upper-knee member (second member)
30 Knee joint mechanism (articulation part)
35 Rotating portion 40 Expansion device 73 First spindle (power transmission portion)
100 Damping section M Motor (power source)
T Transmission (power transmission part)
L1 Virtual line L2 Virtual line (another virtual line)

Claims (9)

A first member;
A second member;
a connecting portion that connects the first member and the second member so as to change the angle between the first member and the second member;
A joint device including an extension device that can change the angle formed between the first member and the second member by extending and contracting,
The telescopic device is
A power source and
a power transmission unit that transmits power from the power source,
The power transmission unit is
a power transmission path that transmits the power of the power source;
a damping unit that is connected to the power transmission path and that damps the movement of the power transmission path,
The power source generates rotational power,
the damping unit is a rotary damper that is provided to damp the rotational power transmitted to the power transmission path, includes a damper body and a rotary shaft, and is provided to apply a predetermined rotational resistance to relative rotation between the damper body and the rotary shaft.
Coupling device. 2. The coupling device of claim 1,
the power transmission unit further includes a speed change unit that is provided on the power transmission path and changes the speed of the rotational power of the power source,
The damping portion is provided to be connected to the transmission portion. 3. The coupling device according to claim 2,
the transmission unit includes a speed increasing mechanism that increases the rotational power of the power source,
The coupling device is configured so that the damping unit is connected to the power transmission path downstream of the speed change unit when the power source is located upstream. The coupling device according to any one of claims 1 to 3,
The damping portion is disposed between the power source and a member that constitutes the power transmission path. The coupling device according to any one of claims 1 to 4,
The joint device is a prosthetic leg,
The first member is provided with a swing shaft that is disposed forward and spaced apart from an imaginary line that connects the heel and the pivoting portion of the connecting portion when the heel lands. 6. The coupling device according to claim 5,
The joint device, wherein the swing axis is located on or in the vicinity of another imaginary straight line connecting the toe and the connecting portion when the toe lands. 7. A coupling device according to any one of claims 1 to 6,
The power transmission unit further includes a damping operation unit that operates the damping unit at a predetermined timing.
Coupling device. A coupling device according to any one of claims 1 to 7,
the rotary shaft is connected to a fixed portion via a clutch mechanism including a first clutch member and a second clutch member;
In a clutch disengaged state in which the first clutch member and the second clutch member are separated, the rotational power is not attenuated,
The rotational power is attenuated in a clutch engagement state in which the first clutch member and the second clutch member are engaged .
Coupling device. A coupling device according to claim 8 dependent on claim 7,
The joint device is a prosthetic leg,
The damping actuation unit includes an actuation lever located above the second clutch member when the prosthetic leg is upright,
The operating lever is provided so as to be able to press down the second clutch member when the heel of the prosthetic leg lands and mechanically operate the damping unit.
Coupling device.