JP6172627B2 - Knee joint - Google Patents

Description

  The present invention relates to a knee joint for a thigh prosthesis, or a knee joint for an orthosis that assists the extension of the knee, which does not require an external power source.

  For patients with thigh amputation, the loss of the knee joint has a significant impact on daily life. Therefore, the function of the knee joint as an alternative function is very important. However, most existing knee joints cannot generate an extension torque in the knee extension direction during the stance phase, and this extension torque must be generated by the user in some way. This is a big burden when going up and down hills.

  In addition, since such a knee joint is a passive mechanism, it leads to instability of movement, disruption of synchronization of movement, and reduction of walking speed. It also causes skin problems such as skin shear and / or ulcers.

  In order to solve these problems, a prosthetic leg with a drive source for a patient who has a knee upper limb amputation having a knee joint that generates extension torque has been proposed (for example, Patent Document 1).

  The prosthetic leg with a drive source described in Patent Document 1 is designed to generate mechanical energy necessary for moving the prosthetic leg from an actuator that is powered. A sensor is provided on a healthy leg to sense the movement of the healthy leg, and the control system controls the prosthetic leg in real time by an actuator provided on the prosthetic leg so as to enable a coordinated movement accordingly.

JP 2005-536318 A

  However, the above-mentioned artificial leg with a drive source described in Patent Document 1 uses a motor, a battery, and various sensors, and thus has problems such as high cost, heavy weight, and physique limitation. Therefore, it has not reached widespread use.

  Therefore, a knee joint that does not require an external power source and is capable of regenerating energy during walking and that is capable of generating extension torque with a small, lightweight and simple structure is expected.

  Accordingly, an object of the present invention is to provide a knee joint that can generate an extension torque without an external power source.

  Another object of the present invention is to provide a knee joint that is capable of generating an extension torque while having a small size and light weight and a simple structure.

  According to the present invention, in a knee joint having a thigh side link fixed to the thigh side, a crus side link fixed to the crus side, and a shaft connecting the thigh side link and the crus side link, Or an input cylinder arranged at the position of the crus, an output cylinder disposed between the thigh side link and the crus side link, and a hydraulic circuit that connects the input cylinder and the output cylinder, and during walking operation The input cylinder is compressed by the floor reaction force, and this input is transmitted to the output cylinder via the hydraulic circuit, and a knee joint is provided that generates an extension torque on the thigh side link by the force output from the output cylinder.

  During walking motion, the input cylinder is compressed by floor reaction force, and this input is transmitted to the output cylinder via the hydraulic circuit, and the force output from the output cylinder generates an extension torque on the thigh-side link. Therefore, without using a motor, a battery, and various sensors, an extension torque can be generated in the knee joint with a simple structure, and a reduction in size and weight can be achieved.

  The input cylinder is preferably composed of a plurality of input cylinders arranged at the sole position. As a result, more output can be obtained from the pressure distribution of the sole during walking. Further, the necessary stroke length can be divided.

  The input cylinder and the output cylinder are preferably provided with a spring for restoring the piston position. As a result, the piston position is restored by the restoring force of the spring, and the continuous movement of sliding and restoration of the piston can be performed, and continuous walking is possible.

  The piston diameter of the output cylinder is preferably larger than the piston diameter of the input cylinder. Thereby, the force for generating the extension torque can be amplified, and a larger extension torque can be generated.

  The input cylinder is preferably provided with a lever mechanism for amplifying the input force, and the output cylinder is preferably provided with a lever mechanism for amplifying the output force and a piston position restoring mechanism. Thereby, the input of the input cylinder and the output of the output cylinder can be amplified with a simple configuration. Moreover, the cross-sectional area ratio between the input cylinder and the output cylinder can be 1: 1, and continuous walking can be realized without using a spring or a flow path for pressure reduction.

  The piston position restoring mechanism has a lever that operates to move the piston of the output cylinder to the original position, and when the knee extends during the swing phase, the output cylinder is compressed by the operation of the lever, and the output cylinder and It is preferable to be configured to restore the piston position of the input cylinder. Thereby, the piston positions of the output cylinder and the input cylinder can be automatically restored during walking.

  The brake lever located on the sole, the brake rotor attached to the lower leg link, the brake caliper attached together with the brake rotor, and the brake lever and brake caliper are connected to transmit the tensile force. It is preferable to further include a load brake mechanism having a wire for the purpose. As a result, constant support can be provided for both walking on flat ground and climbing stairs. In particular, it is possible to prevent knee breakage and further reduce the burden during stairs and uphill movement.

  The input cylinder is disposed at the crus position, connects the lever disposed at the sole, the compression mechanism attached to the crus link, the lever and the compression mechanism, and the floor reaction force received by the lever It is preferable to further include a floor reaction force transmission mechanism having a wire for transmitting the pressure to the compression mechanism. As a result, the hydraulic circuit can be shortened, the flow loss of the working oil can be reduced, and the extension torque can be generated more efficiently.

  According to the present invention, the input cylinder is compressed by the floor reaction force during the walking motion, and this input is transmitted to the output cylinder through the hydraulic circuit, and the extension torque is generated in the thigh side link by the force output from the output cylinder. Thus, an external power source is not required, an extension torque can be generated in the knee joint with a simple structure, and a reduction in size and weight can be achieved. The knee joint can also be used as a power assist device.

It is a side view which shows roughly the structure of the knee joint which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows roughly the generation | occurrence | production state of the extension torque of the knee joint shown in FIG. It is a figure which shows arrangement | positioning of the input cylinder of the knee joint shown in FIG. It is a figure which shows schematically the structure of the hydraulic circuit of the knee joint shown in FIG. It is a side view which shows roughly the structure of the knee joint which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the operation | movement by the side of the input cylinder of the knee joint shown in FIG. It is explanatory drawing which shows the operation | movement by the side of the output cylinder of the knee joint shown in FIG. It is explanatory drawing which shows operation | movement of the piston position restoring mechanism of the knee joint shown in FIG. It is a side view which shows roughly the structure of the knee joint which concerns on the 3rd Embodiment of this invention. It is a side view which shows roughly the structure of the knee joint which concerns on the 4th Embodiment of this invention. It is explanatory drawing which shows operation | movement of the load brake mechanism of the knee joint shown in FIG. It is a side view which shows roughly the structure of the knee joint which concerns on the 5th Embodiment of this invention.

  FIG. 1 shows the configuration and mounting state of a knee joint 100 according to the first embodiment of the present invention, and FIG. 2 shows the angle change of the knee joint portion when an extension torque is generated in the knee joint 100 of FIG. FIG. 3 shows the arrangement of the input cylinder 40 of the knee joint 100 of FIG. FIG. 4 shows a configuration example of the hydraulic circuit 60 of the knee joint 100 shown in FIG.

  As shown in FIG. 1, the knee joint 100 can rotate a thigh side link 10 fixed to the thigh side, a crus side link 20 fixed to the crus side, and the thigh side link 10 and the crus side link 20. And the input cylinder 40 embedded in the sole position, the output cylinder 50 that generates the extension torque, and the hydraulic circuit 60 that connects the input cylinder 40 and the output cylinder 50.

  The thigh side link 10 is composed of, for example, a belt-like plate member. An upper end portion of the thigh side link 10 is rotatably attached to a thigh side attachment member 12 wound around the thigh via a shaft 11, and a lower end portion is connected to the thigh side link via a shaft 30. 20 is connected. As shown in FIG. 2, the thigh-side link 10 can be rotated within the range of the angle θ by the output of the output cylinder 50. The angle θ is, for example, 13 degrees.

  The crus link 20 is formed of, for example, a belt-like plate member similar to the thigh link 10. The upper end portion of the crus link 10 is connected to the thigh link 10 via a shaft 30, and the lower end portion rotates via a shaft 21 to a crus attachment member 22 wound around the lower leg. It is attached as possible.

  The input cylinder 40 includes a piston 41, a piston rod 42, and a spring 43 that restores the piston position. The input cylinder 40 is embedded in the sole position, for example, the bottom of the shoe S. In this example, three input cylinders 40 are used. As shown in FIG. 3, the three input cylinders 40 are arranged at three locations, the toe portion, the heel portion, and the heel portion, from which the greatest output can be obtained from the pressure distribution of the sole. The tip of the piston rod 42 of the piston 41 is exposed from the bottom of the shoe S by a predetermined length (stroke length). In the present embodiment, the piston diameter and stroke length of the input cylinder 40 are designed based on the results of a normal person's walking analysis. For example, the diameter of the piston 41 at the toe portion is 15 mm, the diameter of the piston 41 at the collar portion is 7.5 mm, and the diameter of the piston 41 at the upper portion of the collar is 4.0 mm. In order to reduce the size, it is desirable that the stroke length of the input cylinder 40 installed at the bottom of the shoe S is as short as possible. Therefore, a plurality of input cylinders 40 may be provided to divide a necessary stroke length. For example, the number of pistons at the toe may be 2, the number of pistons at the heel may be 4, and the number of pistons at the top of the heel may be 1. The stroke length of each piston was 3.6 mm. It should be noted that the piston position can be restored by the force of the spring 43 by reducing the pressure of the hydraulic circuit 60 during the swing phase.

  The output cylinder 50 includes a piston 51, a piston rod 52, a support member 53, and a spring 54. The output cylinder 50 is disposed between the thigh side link 10 and the crus side link 20. That is, the output end of the piston rod 52 is connected to the upper end portion of the thigh-side link 10 via the shaft 11. One end of the support member 53 is fixed to the bottom of the output cylinder 50, and the other end is connected to the lower end of the crus link 20 via the shaft 21. In order to obtain an amplified output, the cross-sectional area ratio between the input cylinder 40 and the output cylinder 50 is set to, for example, 1: 2.4. A spring 54 for restoring the piston position is provided inside the output cylinder 50.

  The hydraulic circuit 60 is a closed circuit that connects the input cylinder 40 and the output cylinder 50, and as shown in FIG. 4, an electromagnetic valve 61, a check valve, 62 and 63 and reserve tanks 64 and 65 are incorporated. Note that the configuration of the hydraulic circuit 60 is not limited to this.

  During continuous walking, the flow path control is performed by the electromagnetic valve 61. That is, when the input cylinder 40 is compressed by the floor reaction force in the stance phase as shown by an arrow A in FIG. 4, the oil in the input cylinder 40 flows into the output cylinder 50 through the check valve 62. To do. Further, during the swing phase, as indicated by an arrow B in FIG. 4, the oil in the output cylinder 50 flows into the reserve tank 64 via the electromagnetic valve 61. Thereby, the inside of the flow path is decompressed, and the positions of the pistons 41 and 51 are restored by the force of the springs 43 and 54. As a result, the oil flows from the reserve tank 65 into the input cylinder 40 via the check valve 63.

  In such a configuration, when the input end of the piston rod 42 of the input cylinder 40 embedded in the bottom of the shoe S contacts the floor (road surface), the input cylinder 40 is compressed by the floor reaction force. Since the floor reaction force of the input is amplified by reducing the cross-sectional area of the input cylinder 40 and increasing the cross-sectional area of the output cylinder 50, a large output can be generated.

  Thus, in the knee joint 100 according to the present embodiment, the input cylinder 40 embedded in the bottom of the shoe S, the output cylinder 50 that generates the extension torque, and the hydraulic circuit 60 that connects the input cylinder 40 and the output cylinder 50. And. During the walking motion, the input cylinder 40 is compressed by the floor reaction force, and this input is transmitted to the output cylinder 50 via the hydraulic circuit 60, and the extension torque (FIG. 1) is applied to the thigh-side link 10 by the force output from the output cylinder 50. Middle arrow direction).

  Thereby, an external power source is not required, an extension torque can be generated in the knee joint with a simple structure, and a reduction in size and weight can be achieved.

  The input cylinder 40 includes a plurality of input cylinders 40 arranged at the sole position, so that an input by a floor reaction force can be obtained at each position during walking. Further, the necessary stroke length can be divided.

  Since the input cylinder 40 and the output cylinder 50 are provided with springs 43 and 54 for restoring the piston position, the piston position is restored by the restoring force of the spring, and the continuous movement of the forward and backward movement of the piston is performed. And continuous walking is possible.

  Since the diameter of the piston 51 of the output cylinder 50 is formed larger than the diameter of the piston 41 of the input cylinder 40, the force for generating the extension torque can be amplified, and a larger extension torque can be generated. Is possible.

  FIG. 5 schematically shows the configuration and mounting state of the knee joint 200 according to the second embodiment of the present invention, and FIG. 6 shows the operating state of the input side amplification lever 70 of the knee joint 200 of FIG. 7 shows an operating state of the output side amplification lever 80 of the knee joint 200 of FIG. 5, and FIG. 8 shows an operating state of the piston position restoring mechanism 90 of the knee joint 200 of FIG.

  As shown in FIG. 5, the knee joint 200 can rotate the thigh side link 10 fixed to the thigh side, the thigh side link 20 fixed to the thigh side, the thigh side link 10 and the thigh side link 20. The input cylinder 40 embedded in the sole position, the output cylinder 50 generating the extension torque, the hydraulic circuit 60A connecting the input cylinder 40 and the output cylinder 50, and the input side amplification lever 70. The output side amplification lever 80 and the piston position restoring mechanism 90 are provided.

  In the second embodiment, the thigh-side link 10, the crus-side link 20, and the shaft 30 have the same configuration as that of the above-described first embodiment. Omitted. Further, the input cylinder 40 and the output cylinder 50 have a cross-sectional area ratio of 1: 1 and one input cylinder 40. Furthermore, the input cylinder 40 and the output cylinder 50 do not have a spring for restoring the piston position.

  The hydraulic circuit 60 </ b> A is a closed circuit including a pipe connecting the input cylinder 40 and the output cylinder 50. In this case, a solenoid valve, check valve, reserve tank, etc. are not required.

  The input side amplification lever 70 is a lever mechanism, and is rotatably mounted on the bottom surface of the shoe S via a shaft 71 as shown in FIG. In this example, the lever ratio of the input side amplification lever 70, that is, the ratio of the distance between the fulcrum to the force point and the fulcrum to the action point, that is, L1: L2 is set to 1: 4.24. In addition, the shape and mounting position of the input side amplification lever 70 can be appropriately designed according to the shoe S. By providing the input side amplification lever 70, the extension torque of the thigh side link 10 during walking can be supported by about 40%.

  The output side amplification lever 80 is a lever mechanism. As shown in FIG. 7, one end of the output side amplification lever 80 is rotatably mounted on the upper portion of the output cylinder 50 via a shaft 81. The other end of the output side amplification lever 80 is connected to the piston position restoring mechanism 90. The lever ratio of the output side amplification lever 80 can be appropriately designed based on the required amplification amount.

  The piston position restoring mechanism 90 includes a restoring lever 91, a shaft fixing member 92, a connecting member 93, a hinge member 94, and an action member 95. The restoring lever 91 is rotatably mounted on a shaft fixing member 92 provided at the lower portion of the output cylinder 50 via a shaft. The restoring lever 91 can be operated to move the piston 51 to the original position. The connecting member 93 is configured to connect the action point end of the restoring lever 91 and the force point end of the output side amplification lever 80 and transmit the operation of the restoration lever 91 to the output side amplification lever 80. The hinge member 94 is attached to the end of the force point of the restoring lever 91 in a direction perpendicular to the shaft, and is configured to be rotatable outward and not inward. The action member 95 is fixed to the crus link 20 so as to operate together with the crus link 20. The upper end of the action member 95 can operate the restoring lever 91 by contacting the hinge member 94 when the upper end of the action member 95 extends due to the weight and inertia of the lower leg portion during the free leg period.

  The operation of the piston position restoring mechanism 90 during walking will be described with reference to FIG. In the stance phase, as shown in FIG. 8A, the action member 95 and the hinge member 94 do not contact each other. This state is a state after the knee extension torque is generated by the output cylinder 50. Next, in the swing leg period shown in FIG. 8B, the knee is bent, so that the upper end of the action member 95 and the hinge member 94 are brought into contact with each other, and the hinge member 94 is rotated outwardly. Passes while the upper end of is in contact with the hinge member 94. Next, as shown in FIG. 8C, the upper end of the action member 95 comes into contact with the hinge member 94 and the hinge member 94 does not rotate inward because the knee extends due to the weight and inertia of the lower leg. Therefore, the restoring lever 91 is pushed upward. Thereby, the power point end of the output side amplification lever 80 is pulled downward via the connecting member 93, and the position of the piston 51 of the output cylinder 50 is restored. At the same time, the position of the input cylinder 40 is also restored via the hydraulic circuit 60A. Then, the input cylinder 40 is compressed by the floor reaction force, and this input is transmitted to the output cylinder 50 via the hydraulic circuit 60A, and the extension torque is generated in the thigh side link 10 by the force output from the output cylinder 50. The state shown in FIG. That is, the stance phase is entered.

  As described above, in the knee joint 200 according to this embodiment, the input cylinder 40 is provided with the input side amplification lever 70 for amplifying the input force (floor reaction force), and the output cylinder has an output. An output side amplifying lever 80 is provided for amplifying the force, and a piston position restoring mechanism 90 is provided for enabling continuous walking. Thereby, the cross-sectional area ratio of the input cylinder 40 and the output cylinder 50 can be 1: 1, and continuous walking can be realized without using a spring for restoring the piston position or a flow path for pressure reduction.

  The piston position restoring mechanism 90 has a restoring lever 91 for operating the output cylinder 50. When the knee extends during the swing leg period, the output cylinder 50 is compressed by the operation of the restoring lever 91, and the output cylinder 50 and By restoring the piston position of the input cylinder 40, the piston positions of the output cylinder 50 and the input cylinder 40 can be automatically restored during walking.

  In the above-described first embodiment, the example in which the input cylinder 40 is embedded in the bottom of the shoe S has been described. However, the present invention is not limited to this. For example, the input cylinder 40 may be directly attached to the bottom of the artificial leg. In the case of a prosthetic leg, since the lower leg part is made of a rod such as aluminum, the input cylinder 40 may be installed at the ankle part of the prosthetic leg, the middle part of the lower leg, or the knee side end part. When the input cylinder 40 is installed in the middle part of the lower leg or the knee side end part of the lower leg, the flow path of the hydraulic oil is shortened and the loss can be reduced.

  FIG. 9 schematically shows the configuration and mounting state of the knee joint 300 according to the third embodiment of the present invention, and this embodiment is an example in which the input cylinder 40 is mounted on the ankle portion of the artificial leg. As shown in FIG. 9, the knee joint 300 is attached to the ankle part, the thigh side link 10 fixed to the thigh side, the shaft 30 that rotatably connects the thigh side link 10 and the crus side rod 20A, and the ankle part. The input cylinder 40, the output cylinder 50 that generates the extension torque, and the hydraulic circuit 60 that connects the input cylinder 40 and the output cylinder 50 are provided. In this case, the lower end of the output cylinder 50 is directly fixed to the rod 20 </ b> A on the crus side via the support member 53. The output cylinder 50 may be directly fixed to the rod 20A on the crus side without using the support member 53.

  In the knee joint 300, the piston 41 of the input cylinder 40 is arranged on the lower leg side of the artificial leg, and the piston rod 42 is arranged on the leg side of the artificial leg. With this configuration, when the foot comes into contact with the floor (road surface), the input cylinder 40 is compressed by the floor reaction force. The same effects as those of the first embodiment described above can be obtained. In this case, it is not necessary to thicken the bottom of the shoe S in order to embed the input cylinder 40.

  FIG. 10 schematically shows a configuration and a mounting state of a knee joint 400 according to the fourth embodiment of the present invention. In this embodiment, the input cylinder 40 is mounted on the upper part of the crus link 20A, near the knee. In this example, a load brake mechanism 70A is provided. FIG. 11 schematically shows the motion state during walking, where FIG. 11A shows the state of the swing phase, FIG. 11B shows the state of the brake operation in the stance phase, c) shows the output state in the stance phase.

  As shown in FIG. 10, the knee joint 400 can rotate the thigh side link 10 fixed to the thigh side, the thigh side link 20A fixed to the thigh side, the thigh side link 10 and the thigh side link 20A. An input cylinder 40 embedded in the sole position, an output cylinder 50 that generates extension torque, a hydraulic circuit 60B that connects the input cylinder 40 and the output cylinder 50, a load brake mechanism 70A, An output side amplification lever 80 and a piston position restoring mechanism 90 are provided. The output side amplification lever 80 may not be provided.

  In the fourth embodiment, the thigh-side link 10, the crus-side link 20A, the shaft 30, the input cylinder 40, the output cylinder 50, and the hydraulic circuit 60B have substantially the same configuration as that of the above-described third embodiment. Moreover, since the output side amplification lever 80 and the piston position restoring mechanism 90 have the same configuration as that of the second embodiment described above, detailed description thereof is omitted here.

  The load brake mechanism 70A includes a brake lever 70a disposed on the sole, a brake rotor 70b mounted on the crus link 20A, a brake caliper 70c mounted together with the brake rotor 70b, and a brake lever 70a. The brake caliper 70c is connected to the wire 70d for transmitting a tensile force.

  The brake lever 70a is embedded in the sole, for example, the bottom of the shoe S. It is rotatably mounted on the bottom surface of the shoe S via the shaft 71A. The wire 70d can be pulled and released by turning the brake lever 70a. When the brake lever 70a is disposed, the timing at which the braking force is generated differs depending on whether the brake lever 70a is disposed closer to the toe or closer to the toe. From the experimental results, when installed on the heel, the timing at which the braking torque is generated is earlier than the knee joint torque. Therefore, the knee is fixed at an unnatural angle, which may hinder walking. On the other hand, when it arrange | positions to a toe, the timing which generate | occur | produces braking torque is later than knee joint torque. Therefore, there is a possibility that the knee will be broken at the moment of grounding. Further, in climbing stairs, the timing at which braking torque is generated is constant no matter where it is placed. From these results, it is preferable to arrange the brake lever 70a near the center of the bottom of the shoe S.

  The brake rotor 70b is a flat plate formed in a fan shape. The brake rotor 70b is attached to the crus link 20A so as to rotate with the knee flexion. The load brake mechanism 70A must operate even when the legs are bent greatly during stairs climbing. Since the braking force must be applied to the brake rotor 70b in the angle range to be supported, the size of the brake rotor 70b is important. From the results of conventional gait analysis, it is clear that when climbing stairs, the knee joint is grounded with a bending angle of 63 degrees (deg). Therefore, in this embodiment, the brake rotor 70b has a sector shape of 100 degrees (deg) so that the load brake mechanism 70A operates at this angle. Moreover, the radius of the brake rotor 70b was set to 75 mm, which is the smallest thing that can be attached. The values of the angle and the radius of the brake rotor 70b are examples, and the present invention is not limited to this.

  The brake caliper 70c is mounted so as not to rotate together with the knee flexion. It has two contact pads facing each other, and when the wire 70d is pulled, the braking force is applied by sandwiching the brake rotor 70b from both sides.

  The wire 70d is a means for transmitting force from the brake lever 70a to the brake caliper 70c and for operating the brake caliper 70c. The wire 70d is inserted through the outer tube and can move freely along the outer tube. Both ends of the outer tube are fixed to the shoe S and the brake caliper 70c, respectively. As a means for operating the brake caliper 70c, a hydraulic type may be used instead of the mechanical type using the wire 70d.

  During walking, the wire 70d is pulled by the rotation of the brake lever 70a, the brake caliper 70c is operated, and the braking force is applied to the brake rotor 70b, thereby restricting the rotation of the brake rotor 70b and suppressing the bending of the knee. It is like that.

  Since the brake lever 70a is gradually pushed during the stance period during walking, the braking force of the brake caliper 70c also changes. At this time, if the braking force becomes small and the knee joint cannot be supported, the knee is bent. Also, when the timing of generating the braking force is too late, sufficient braking force cannot be obtained and the knee is bent. On the other hand, if it is too early, the knee is fixed in an unnatural state and it becomes difficult to walk. Accordingly, the design of the arrangement position and dimensions of the brake lever 70a is important. Based on the relationship between the tensile length of the wire 70d and the braking force, the arrangement position and dimensions of the brake lever 70a are determined. When pulling the wire 70d by the brake lever 70a, if a sufficient braking force cannot be obtained by the brake caliper 70c, knee bending occurs. At this time, in order not to cause the knee to break, a braking torque greater than the knee joint torque during walking is required. From past studies, it has been clarified that a knee joint torque of about 1.5 Nm / kg is generated at the maximum in stairs climbing of healthy subjects. Therefore, the load brake mechanism 70A is designed so as to obtain a braking torque greater than the knee joint torque. For example, when it is assumed that a person with a weight of 60 kg is used, the knee joint torque generated at the knee joint is 90 Nm. Here, since the radius of the brake rotor 70b that gives the braking force by the brake caliper 70c is 75 mm, the required braking force is 1200N. Due to the relationship between the tensile length of the wire 70d and the braking force, the required input is at least 305N. Therefore, it is necessary to pull the wire 70d about 15.6 mm in order not to cause the knee to bend. Note that the torque value, the braking force value, the input value, and the displacement (pulling distance) value of the wire 70d are examples, and the present invention is not limited to this.

  The operation of the load brake mechanism 70A during walking will be described with reference to FIG. In the swing phase shown in FIG. 11A, the knee is bent and the brake lever 70a does not contact the ground, so the load brake mechanism 70A does not operate. In the stance period shown in FIG. 11 (b), the brake lever 70a is rotated by receiving a floor reaction force when contacting the ground, and the wire 70d is pulled by the rotation of the brake lever 70a to operate the brake caliper 70c. By applying a braking force to the brake rotor 70b, the rotation of the brake rotor 70b is limited, and the bending of the knee is suppressed. Next, as shown in FIG. 11 (c), when the input cylinder 40 is compressed by the floor reaction force with the brake lever 70 a rotated to the bottom surface, the oil in the input cylinder 40 flows into the output cylinder 50. And an extension torque is generated by the output cylinder 50.

  As described above, in the knee joint 400 according to the present embodiment, the load brake mechanism 70A is provided so that the knee is prevented from bending, and then the output cylinder 50 generates an extension torque to support walking. As a result, a certain level of support can be provided for both walking on flat ground and climbing stairs. In particular, it is possible to prevent knee breakage and further reduce the burden during stairs and uphill movement. Since the input cylinder 40 is mounted on the upper part of the crus link 20A and close to the knee, the hydraulic circuit 60B can be shortened, the flow loss of the working oil can be reduced, and the extension torque can be generated more efficiently. be able to.

  FIG. 12 schematically shows the configuration and mounting state of a knee joint 500 according to the fifth embodiment of the present invention, and this embodiment is an example in which the input cylinder 40 is mounted at a position close to the knee of the lower leg portion of the artificial leg. It is.

  As shown in FIG. 12, the knee joint 500 can rotate the thigh side link 10 fixed to the thigh side, the thigh side link 20 fixed to the thigh side, the thigh side link 10 and the thigh side link 20. , An input cylinder 40 embedded in the sole position, an output cylinder 50 that generates extension torque, a hydraulic circuit 60B that connects the input cylinder 40 and the output cylinder 50, and a floor reaction force transmission mechanism 70B. And an output side amplification lever 80 and a piston position restoring mechanism 90.

  In the fifth embodiment, the thigh-side link 10, the crus-side link 20, the shaft 30, the input cylinder 40, the output cylinder 50, the output-side amplification lever 80, and the piston position restoring mechanism 90 are the same as those described above. Since the configuration is the same as that of the embodiment, detailed description thereof is omitted here.

  The floor reaction force transmission mechanism 70B connects the lever 70e disposed on the sole, the compression mechanism 70f attached to the crus link 20, the lever 70e and the compression mechanism 70f, and the floor received by the lever 70e. It is comprised from the wire 70g for transmitting reaction force to the compression mechanism 70f.

  The lever 70e is embedded in the sole part position, for example, the bottom part of the shoe S. It is rotatably mounted on the bottom surface of the shoe S via the shaft 71B. The wire 70g can be pulled and released by the rotation of the lever 70e. In the present embodiment, the lever 70e is disposed close to the heel so that an extension torque is generated at the moment of grounding.

  The compression mechanism 70f includes a first rotation arm 70h, a second rotation arm 70i, and a rotation shaft 70j, and the rotation arm 70h is a piston rod of the input cylinder 40 by a pulling force of the wire 70g. It is comprised so that the front-end | tip of 42 may be pushed. The wire 70g is inserted through the outer tube, and one end is fixed to the lever 70e and the other end is fixed to the compression mechanism 70f. Both ends of the outer tube are fixed to the shoe S and the compression mechanism 70f, respectively.

  As described above, in the knee joint 500 according to the present embodiment, the floor reaction force transmission mechanism 70B is provided, the input cylinder 40 is disposed at a position close to the knee of the crus, and the hydraulic circuit 60B is shortened. Oil flow loss can be reduced, and extension torque can be generated more efficiently.

  In the above-described first embodiment, the example in which the three input cylinders 40 are arranged at the three locations on the bottom of the shoe S has been described. However, the present invention is not limited to this. For example, one input cylinder 40 may be used and disposed at one location on the bottom of the shoe S.

  In the second embodiment described above, the input side amplification lever 70 is provided in the input cylinder 40 and the output side amplification lever 80 is provided in the output cylinder 50. However, the present invention is not limited to this. For example, an amplification lever may be provided only in either the input cylinder 40 or the output cylinder 50.

  The embodiments described above are illustrative of the present invention and are not intended to be limiting, and the present invention can be implemented in various other modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

  The knee joint of the present invention can be used as a knee joint for a femoral prosthesis or a power assist device.

DESCRIPTION OF SYMBOLS 10 Thigh side link 11, 21, 30, 71, 81 Axis 12 Thigh side attachment member 20 Lower leg side link 20A Rod 22 Lower leg side attachment member 40 Input cylinder 41, 51 Piston 42, 52, 52 'Piston rod 43, 54 Spring 50 Output cylinder 53 Support member 60, 60A, 60B Hydraulic circuit 70 Input side amplification lever 70A Load brake mechanism 70B Floor reaction force transmission mechanism 70a Brake lever 70b Brake rotor 70c Brake caliper 70d, 70g Wire 70e Lever 70f Compression mechanism 70h First turn Moving arm 70i Second rotating arm 70j Rotating shaft 80 Output side amplification lever 90 Piston position restoring mechanism 91 Restoring lever 92 Shaft fixing member 93 Connection member 94 Hinge member 95 Working member 100, 200, 300, 400, 5 0 knee joint L leg S shoes

Claims (5)

In a knee joint having a thigh side link fixed to the thigh side, a crus side link fixed to the crus side, and a shaft connecting the thigh side link and the crus side link,
An input cylinder arranged at the sole or crus position;
An output cylinder disposed between the thigh side link and the crus side link;
A hydraulic circuit that connects the input cylinder and the output cylinder;
During the walking motion, the input cylinder is compressed by floor reaction force, and this input is transmitted to the output cylinder via the hydraulic circuit, and the extension torque is generated in the thigh-side link by the force output from the output cylinder ,
The knee joint according to claim 1, wherein the output cylinder is provided with a lever mechanism for amplifying an output force and a piston position restoring mechanism . Wherein the input cylinder, the knee joint of claim 1, wherein the lever mechanism for amplifying the input force is al provided. The piston position restoring mechanism has a lever for operating the piston of the output cylinder to move to the original position, and the output cylinder is compressed by the operation of the lever when the knee extends during the free leg period. The knee joint according to claim 2 , wherein the knee joint is configured to restore piston positions of the output cylinder and the input cylinder.   A brake lever arranged at the sole, a brake rotor attached to the lower leg link, a brake caliper attached together with the brake rotor, and the brake lever and the brake caliper are connected and pulled. The knee joint according to claim 1, further comprising a load brake mechanism having a wire for transmitting force. The input cylinder is disposed at the lower leg position,
A lever disposed on the sole, a compression mechanism mounted on the crus link, the lever and the compression mechanism are connected, and the floor reaction force received by the lever is transmitted to the compression mechanism. The knee joint according to claim 1, further comprising a floor reaction force transmission mechanism having a plurality of wires.

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