JP2001218778A - Right foot - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A hydraulic pressure provided on a knee of a prosthesis by detecting contraction movement of muscle at a stump of a cut leg cut proximally from a knee by a sensor and detecting information from the sensor. By controlling the degree of throttle of the variable valve in the cylinder, the knee resistance of the prosthesis in use can be adjusted arbitrarily to provide a prosthesis that can easily walk on stairs, hills, and flats without breaking the knee of the prosthesis Is to do. . SOLUTION: A first pressure sensor 6 for detecting a weight load and a contraction movement of a muscle at a stump of the cut leg is provided on an inner surface in a thigh socket 2 of a prosthesis 1 attached to the stump of the cut leg. A second pressure sensor 7 for mainly detecting a weight load is provided on the bottom surface in the thigh socket 2, and when the pressure of the first pressure sensor 6 is higher than the pressure of the second pressure sensor 7 by a predetermined pressure or more, the knee joint 9 The degree of throttling of the variable valve 8 of the hydraulic cylinder 5 for adjusting the bending / extension resistance of the hydraulic cylinder 5 is controlled based on the detection information of the pressure difference between the sensors 6 and 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic cylinder which is mounted on a leg cut proximally of a knee as a substitute for the leg and adjusts the resistance of the knee joint to flexion and extension. The movement of the liquid in the cylinder chambers on both sides of the piston is related to the prosthesis performed through the variable valve. In particular, the contraction movement of the muscle at the stump of the cutting leg is detected by a sensor, and the hydraulic pressure is thereby detected. The present invention relates to a prosthetic foot that can adjust the degree of throttle of a variable valve in a cylinder to freely adjust the bending and stretching resistance of a knee of a prosthesis in use, and can walk on stairs, hills, and level ground without breaking a knee of a prosthesis. .

[0002]

2. Description of the Related Art Conventionally, a pneumatic or hydraulic cylinder is mounted on a leg which has been cut proximally of a knee as a substitute for the leg, and a pneumatic or hydraulic cylinder is used to adjust the bending and extension resistance of the knee joint. Prosthetic limbs performed using are known.

[0003] In a conventional prosthesis, bending of a knee joint,
The resistance in extension is achieved by using a pneumatic or hydraulic cylinder.In this case, the movement of the fluid in the cylinder chambers on both sides of the piston of the pneumatic or hydraulic cylinder is performed through a variable valve. ing.

[0004]

However, once the variable valve is adjusted, it is constant or only changes according to the walking speed, and cannot be adjusted arbitrarily during mounting. The person could not flex or extend the legs in response to changes in the use environment.

[0005] When the use environment of the prosthetic limb user changes, that is, when walking downhill, the knees bend slowly while supporting the weight, and if the knees are bent deeper than necessary, it is difficult to walk. The knee should bend at a shallow angle and stop. Conversely, when walking uphill, the knees should bend to some extent, but they must be free from knee breaks that could cause them to fall. And when weight is applied at the same time, the resistance to bending is high and the resistance to stretching is low. Also, when walking slowly on flat ground, it is better for the knees to be easily bent and stretched, and for running on flat grounds, it is better for the knees to have high resistance and be hard to bend and stretch.

SUMMARY OF THE INVENTION In view of the above problems, the present invention has been made to solve the problems, and an object of the present invention is to provide a stump of a cutting leg that is cut near a knee. The contraction movement of the muscles of the prosthesis is detected by the sensor, and the resistance of the knee of the prosthesis in use is controlled by controlling the degree of throttle of the variable valve in the hydraulic cylinder provided on the knee of the prosthesis based on the detection information from the sensor It is an object of the present invention to provide a prosthetic leg that can be easily walked on stairs, hills, and level ground without breaking the knee of the prosthetic leg.

[0007]

In order to achieve the above object, the present invention is applied to a leg cut proximally of a knee as a substitute for the leg, and adjusts the resistance of the knee joint to flexion and extension. The prosthesis is equipped with a hydraulic cylinder, and the movement of liquid in the cylinder chambers on both sides of the piston of the hydraulic cylinder is performed through a variable valve. A first pressure sensor for detecting a weight load and a contraction movement of a muscle at a stump of a cutting leg is provided on an inner side surface, and a second pressure sensor for mainly detecting a weight load is provided on a bottom surface in a thigh socket. When the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor by a predetermined pressure or more, the degree of throttle of the variable valve of the hydraulic cylinder that adjusts the resistance of flexion and extension of the knee joint is determined by the pressure difference between the two sensors. Inspection Consisting means for controlling the information.

Here, the first pressure sensor comprises a first bag provided on the inner surface in the thigh socket and a first signal path for transmitting the pressure of the first bag to the variable valve. , A second provided on the inner bottom surface in the thigh socket
The variable valve comprises a variable valve sliding cylinder chamber, a spool for sliding the cylinder chamber to control the fluid flow, and a variable valve. A first diaphragm and a second diaphragm attached to both ends of a spool that always protrude from both ends of the sliding cylinder chamber, a first signal path connection storage chamber and a first signal path connection side liquid storage chamber partitioned by the first diaphragm;
It is composed of a second signal path connection reservoir, a second signal path connection side liquid reservoir, and a spring disposed in the first signal path connection side liquid reservoir, which is partitioned by the second diaphragm. An inner space in which a sliding portion of the spool is formed with a throttle portion having a smaller diameter at the center portion than on both sides, and a sufficient clearance is formed on an outer periphery of the throttle portion with an inner peripheral surface of the variable valve sliding cylinder chamber. Are formed on the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber, and connection holes are respectively formed with fluid communication passages respectively communicating with the cylinder chambers on both sides of the piston of the hydraulic cylinder with the piston interposed therebetween. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments of the invention shown in the drawings. Here, FIG. 1A is a side sectional view of the prosthesis, and FIG.
FIG. 2A is a diagram showing the relationship between the variable valve and the hydraulic cylinder, FIG.
(A) is a side sectional view of the prosthesis when going down the stairs, FIG. 2 (B)
Is a diagram showing the relationship between the variable valve and the hydraulic cylinder in FIG.
FIG. 3 is a side sectional view of the hydraulic cylinder, and FIG.
4B is a sectional view taken along the arrow in FIG. 3, FIG. 4B is a sectional view taken along the arrow in FIG. 3, and FIG. 5A is a sectional view taken along the arrow in FIG.
FIG. 4B is a cross-sectional view of FIG. 3 when the knee is extended.

In the figure, a prosthetic leg 1 includes a thigh socket 2 attached to a stump of a cutting leg, a knee shaft 3, a lower leg 4 of the knee shaft 3, a hydraulic cylinder 5 for resistance to bending and extension, The lower part of the thigh socket 2 and the lower part 10 which is the upper part of the foot part 4 are mainly connected with the first pressure sensor 6, the second pressure sensor 7 and the variable valve 8. A knee joint 9 composed of the shaft 3, the hydraulic cylinder 5, and the variable valve 8 can bend and extend similarly to the knee of a human leg.

The upper half of the thigh socket 2 is a hollow portion 2a, and the upper end of the thigh socket 2 which is the upper end of the hollow portion 2a is an opening 2b. The stump of the cutting leg is inserted into the hollow portion 2a inside and attached.

The hydraulic cylinder 5 adjusts the resistance of the knee to flexion and extension of the knee shaft 3, and the foot 4 below the knee shaft 3.
It is equipped inside the lower leg 10 on the upper side of the vehicle. A cylinder chamber 5a is provided inside the hydraulic cylinder 5, and a piston 5b is slidably inserted in the cylinder chamber 5a.

The interior of the cylinder chamber 5a is divided on both sides by a piston 5b.
The lower side of b is the cylinder A chamber 5c, and the upper side of the piston 5b is the cylinder B chamber 5d. A liquid such as oil is sealed in a cylinder chamber 5a divided on both sides by a piston 5b. The liquid on both sides of the piston 5b flows in a direction opposite to the moving direction of the piston 5b in accordance with the moving direction of the piston 5b.

One end of a piston rod 5e is fixed to the piston 5b, and the other end of the piston rod 5e extends outside the hydraulic cylinder 5. In this embodiment, the hydraulic cylinder 5 is mounted vertically and the piston rod 5e is extended upward, and its upper end is slightly behind the center of rotation of the knee shaft 3, and the prosthesis 1
Is rotatably connected to a shaft mounted in the left-right direction.

An extension assist spring 5f is provided in one side of the cylinder chamber 5a divided on both sides by the piston 5b, in the drawing, a cylinder A chamber 5c below the piston 5b. The extension assist spring 5f is urged to push the piston rod 5e upward, and acts in a direction to extend the bent prosthesis 1 by the piston rod 5e of the hydraulic cylinder 5 extending upward.

The hydraulic cylinder 5, which is mounted inside the lower leg 10 in the vertical direction in the drawing, has
And is rotatably connected to a shaft attached to the left and right direction of the artificial leg 1.

The first pressure sensor 6 detects the weight load and the contraction movement of the muscle at the end of the cut leg. The first pressure sensor 6 is inserted into the hollow portion 2a of the thigh socket 2 into which the end of the cut leg is inserted. Is provided. The first pressure sensor 6 in this embodiment has a structure that is operated by fluid pressure, and the first pressure sensor 6 is composed of a first bag 6a in which fluid is sealed, and transmits the fluid pressure to the variable valve 8. The first signal path 6b
Is provided.

The first pressure sensor 6 has a first bag 6a.
Is filled with a fluid such as air, and the first bag 6a filled with the fluid is provided on the inner surface of the hollow portion 2a of the thigh socket 2, and the hollow portion 2 of the thigh socket 2
The cut leg is inserted into the cut leg so as to be in close contact with the skin at the stump or with a soft inner socket interposed therebetween.

The first signal path 6b is formed of a path such as a tube, for example, and one end thereof is connected to the first bag 6a and is in communication with the inside of the first bag 6a.
The same fluid as the fluid sealed inside the first bag body 6a is sealed inside b. The other end of the first signal path 6b is connected to the variable valve 8 in communication.

The first pressure sensor 6 is configured to control the skin of the cut end of the cut leg, which is attached to the hollow portion 2a of the thigh socket 2, to contract due to the muscles of the cut end of the cut leg or to carry a weight load. Of the first bag body 6a, and the fluid pressure inside the pressed first bag body 6a is transmitted to the variable valve 8 side through the first signal path 6b to control the variable valve 8. .

The second pressure sensor 7 mainly detects the weight load, and is provided inside the hollow portion 2a of the thigh socket 2 into which the stump of the cutting leg is inserted. The second pressure sensor 7 in this embodiment has a structure operated by a fluid pressure, and the second pressure sensor 7 is composed of a second bag 7a filled with a fluid, and transmits the fluid pressure to the variable valve 8. A second signal path 7b is provided.

The second pressure sensor 7 has a second bag 7a.
Is filled with a fluid such as air, and the first bag body 6a filled with the fluid is provided on the inner bottom surface of the hollow portion 2a of the thigh socket 2 and inserted into the hollow portion 2a of the thigh socket 2. Whether it is in close contact with the skin at the end of the cutting leg,
It comes into contact with the soft inner socket.

The second signal path 7b is formed of a path such as a tube, for example. One end of the second signal path 7b is connected to the second bag 7a and is in communication with the inside of the second bag 7a.
The same fluid as the fluid sealed inside the second bag 7a is sealed inside b. The other end of the second signal path 7 b is connected to the variable valve 8.

The second pressure sensor 7 causes the skin of the cut end of the cutting leg to be attached to the hollow portion 2a of the thigh socket 2 so that the skin of the cut end of the cutting leg is placed in the second bag body 7a on the inner bottom surface. Is pressed, and the pressed fluid pressure inside the second bag body 7a is transmitted to the variable valve 8 side through the second signal path 7b, and the variable valve 8 is controlled.

The variable valve 8 is based on the information of the pressure difference between the first pressure sensor 6 which detects the weight load and the contraction movement of the muscle at the stump of the cutting leg and the second pressure sensor 7 which mainly detects the weight load. The fluid in the cylinder A chamber 5c and the cylinder B chamber 5d on both sides of the piston 5b of the cylinder chamber 5a is controlled in accordance with the moving direction of the piston 5b so as to flow in the direction opposite to the moving direction. The resistance of the knee joint 9 is adjusted by varying the resistance of the knee joint 9.

The variable valve 8 is provided integrally with the upper part of the hydraulic cylinder 5, and has a fluid communication passage 5g and a fluid communication passage 5g.
The liquid in the cylinder A chamber 5c and the cylinder B chamber 5d on both sides of the piston 5b of the cylinder chamber 5a moves the piston 5b by opening and closing and narrowing the connection between the two passages 5g and 5h. The flow rate of the liquid flowing in the direction opposite to the moving direction is controlled according to the direction.

When the information from the first pressure sensor 6 and the information from the second pressure sensor 7 are balanced, the variable valve 8 is fully opened, and the fluid communication passage 5g and the fluid communication passage 5h are in communication with each other. Therefore, the cylinder A chamber 5c and the cylinder B chamber 5d are also in communication with each other via the fluid communication passage 5g and the fluid communication passage 5h.

The variable valve 8 includes a variable valve sliding cylinder chamber 8a, a spool 8b that slides in the cylinder chamber 8a to control the fluid flow, and a spool 8b that always projects from both ends of the variable valve sliding cylinder chamber 8a. 1st diaphragm 8c and 2nd diaphragm 8 attached to both ends of
d, the first signal path connection storage chamber 8e and the first signal path connection side liquid storage chamber 8f partitioned by the first diaphragm 8c,
It is composed of a second signal path connection reservoir 8g, a second signal path connection side liquid reservoir 8h, and a spring 8i arranged in the first signal path connection side liquid reservoir 8f, which is partitioned by the diaphragm 8d.

The variable valve sliding cylinder chamber 8a is formed laterally above the cylinder chamber 5a, and a spool 8b is slidably inserted therein, and the spool 8b slides. By moving, the variable valve 8 is opened and closed.

The center of the spool 8b that slides inside the variable valve sliding cylinder chamber 8a is a narrowed portion 8j having a smaller diameter than both sides, and the outer periphery of the central narrowed portion 8j of the spool 8b is a variable valve. The inner space of the sliding cylinder chamber 8a is formed with a sufficient clearance between itself and the inner peripheral surface of the sliding cylinder chamber 8a. The liquid in the hydraulic cylinder 5 passes through the inner space of the clearance and communicates with the fluid communication passage 5g. It is structured to move back and forth between the passage 5h.

At both ends of the spool 8b, stoppers 8k each having an outer diameter larger than the inner diameter of the variable valve sliding cylinder chamber 8a are attached. The spool 8b is configured to slide and move within the variable valve sliding cylinder chamber 8a within the range of the stoppers 8k at both ends, and the spool 8b is moved to the variable valve sliding cylinder chamber 8a.
It does not protrude from a.

A connection hole 8m to the fluid communication passage 5g and a fluid communication passage 5g are formed on the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber 8a sealed by the spool 8b sliding inside.
h and connection holes 8n are formed respectively. A connection hole 8n formed in the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber 8a is opened and closed by a spool 8b.

The connection holes 8m and 8n are opened by the throttle portion 8j when the spool 8b is moved most toward the first signal path connection storage chamber 8e, so that the fluid communication passage 5g and the fluid communication passage 5h are in communication with each other. Become. The connection hole 8n is closed by the side peripheral surface of the spool 8b when the spool 8b is most moved to the second signal path connection storage chamber 8g side, so that the fluid communication passage 5g and the fluid communication passage 5h are in a non-communication state. become.

The first signal path connection storage chamber 8e which contacts the outside of the first diaphragm 8c attached to one end of the spool 8b.
Communicates with the end of the first signal path 6b. First bag 6
The pressure information a is transmitted to the first signal path connection reservoir 8e by the fluid pressure transmitted through the first signal path 6b, and the information is transmitted by pressing the first diaphragm 8c in contact with the first signal path connection reservoir 8e. Is done.

The first signal path connection side liquid storage chamber 8f in contact with the inside of the first diaphragm 8c attached to one end of the spool 8b is connected to the second signal path connection side opposite the variable valve sliding cylinder chamber 8a. It communicates with the liquid reservoir 8h via the communication passage 8r. As the fluid, for example, the same oil as in the cylinder chamber 5a is filled in the first signal path connection side liquid storage chamber 8f. When the volume in the first signal path connection side liquid storage chamber 8f changes due to the sliding of the spool 8b, the internal fluid flows through the communication path 8r to the second signal path connection side liquid storage chamber 8f.
h.

The first signal path connection side liquid storage chamber 8f includes:
The first diaphragm 8 includes the above-mentioned spring 8i therein.
c, and the pressure difference between the first pressure sensor 6 and the second pressure sensor 7 is adjusted by the strength of the spring 8i. That is, when the pressure from the first pressure sensor 6 is larger than the pressure from the second pressure sensor 7 by the strength of the spring 8i or more, the first diaphragm 8c is on the inner side, that is, on the first signal path connection side liquid storage chamber 8f side. And the spool 8b also moves to the second diaphragm 8d side.

The second signal path connection reservoir 8g that contacts the outside of the second diaphragm 8d attached to the other end of the spool 8b.
Communicates with the end of the second signal path 7b. Second bag 7
The pressure information a is transmitted to the second signal path connection reservoir 8g by the fluid pressure transmitted through the second signal path 7b, and the information is transmitted by pressing the second diaphragm 8d in contact with the second signal path connection reservoir 8f. Is done. The second signal path connection storage chamber 8g has a space in which the second diaphragm 8d can sufficiently move to the same chamber 8g side.

As described above, the second signal path connection side liquid storage chamber 8h, which is in contact with the inside of the second diaphragm 8d attached to the other end of the spool 8b, is located on the opposite side of the variable valve sliding cylinder chamber 8a. It communicates with one signal path connection side liquid storage chamber 8f via a communication path 8r. As the fluid, for example, the same oil as in the cylinder chamber 5a is filled in the second signal path connection side liquid storage chamber 8h.

As described above, the fluid communication passage 5g and the fluid communication passage 5h provided with the variable valve 8 in the middle thereof are connected to the cylinder A chamber 5c on both sides of the piston 5b of the cylinder chamber 5a.
And the passage through which the liquid in the cylinder B chamber 5d flows in the direction opposite to the moving direction of the piston 5b in accordance with the moving direction of the piston 5b.

One end of the fluid communication passage 5g is connected to the cylinder A chamber 5
c, and one end of the fluid communication passage 5h is openly connected to the side surface of the cylinder B chamber 5d. The cylinder A chamber 5c and the cylinder B chamber 5d divided by the piston 5b are connected to the fluid communication passage 5g. The valve 8 and the fluid communication passage 5h can communicate with each other and be shut off.

In the figure, one end of a fluid communication passage 5g is laterally opened and connected to the side surface of the cylinder A chamber 5c, and extends upward from there, and extends upward from the fluid communication passage 5g. 5g is connected to a connection hole 8m on the side surface of the variable valve sliding cylinder chamber 8a in which the variable valve 8 slides.

One end of the fluid communication passage 5h is laterally opened and connected to an upper portion of the side surface of the cylinder B chamber 5d, and extends upward therefrom, and extends upward from the fluid communication passage 5h. 5h is connected to a connection hole 8n on the side surface of the variable valve sliding cylinder chamber 8a in which the variable valve 8 slides.

A needle valve chamber is provided in the middle of one end connected to the lower side surface of the cylinder A chamber 5c of the fluid communication passage 5g, and a needle valve 5i is mounted. The needle valve 5i adjusts the resistance of the liquid flowing through the fluid communication passage 5g.

A check valve 5 that opens toward the fluid communication passage 5g is provided between the fluid communication passage 5g on the way connected to the variable valve sliding cylinder chamber 8a and the upper side of the cylinder B chamber 5d.
j is provided. The check valve 5j is connected to the cylinder B chamber 5
When the hydraulic pressure of d becomes higher than a certain value, it opens so that the liquid can be moved to the cylinder A chamber 5c through the fluid communication passage 5g.

Next, the operation based on the configuration of the above embodiment of the present invention will be described below. Prosthesis 1 at the end of the amputated leg
For example, when walking down with the thigh socket 2 attached, the prosthesis 1 touches the ground in a stretched state when descending the stairs, and starts to gradually turn around the knee portion, that is, the knee axis 3 of the prosthesis 1.

In this case, when the muscle at the stump of the cutting leg is contracted and moved when a force to bend suddenly acts, the muscle at the stump of the cutting leg expands and the thigh socket 2 The first bag 6a of the first pressure sensor 6 provided on the inner peripheral side surface is pressed. In addition, at this time, when the weight is simultaneously applied, the first bag 6a of the first pressure sensor 6 is further pressed.

When the first bag 6a of the first pressure sensor 6 is pressed by the contraction movement of the muscle at the stump of the cutting leg and the weight load, a part of the fluid inside the first bag 6a is released. Moves into the first signal path 6b, one end of which is connected to the first signal path 6b.

Therefore, the fluid in the first signal path 6b is pressed and moves to the other end, and the first signal path connection reservoir of the variable valve 8 to which the other end of the first signal path 6b is connected. A part of the fluid flows into 8e and the pressure increases, and the pressure in the first signal path connection reservoir 8e becomes P1. That is, pressure P1 = muscle contraction F1 + weight load W1.

On the other hand, when weight is applied, the second bag 7 of the second pressure sensor 7 provided on the inner bottom surface of the thigh socket 2
Press a. When the second bag 7a is pressed, a part of the internal fluid moves into and flows into the second signal path 7b, one end of which is connected to the second bag 7a.

Therefore, the fluid in the second signal path 7b is pressed and moves to the other end, and the second signal path connection reservoir of the variable valve 8 to which the other end of the second signal path 7b is connected. A part of the fluid flows into 8g and the pressure increases, so that the pressure inside the second signal path connection reservoir 8g becomes P2. That is, pressure P2 = weight load W2.

When the pressure inside the first signal path connection storage chamber 8e reaches the pressure P1, the first diaphragm 8c causes the first diaphragm 8c to generate the first pressure P1.
A force that fluctuates toward the signal path connection side liquid storage chamber 8f side acts. Similarly, the inside of the second signal path connection storage chamber 8g has a pressure P2.
, The second diaphragm 8d is moved by the pressure P2.
A force fluctuating toward the second signal path connection side liquid reservoir 8h side acts.

Thus, the pressure P1 and the pressure P2 act on the spool 8b slidably inserted into the variable valve sliding cylinder chamber 8a of the variable valve 8 from both ends.

When the pressure difference between the pressure P1 and the pressure P2 acting on both ends of the spool 8b is larger than the spring strength K of the spring 8i in the first signal path connection side liquid storage chamber 8f, that is, P1-P2 When = F1 + (W1-W2)> K, the spool 8b overcomes the urging force of the spring 8i and moves toward the second signal path connection storage chamber 8g.

The side surface of the spool 8b that moves toward the second signal path connection storage chamber 8g narrows or closes the opening area of the connection hole 8n opened on the side surface of the variable valve sliding cylinder chamber 8a.

The end of the fluid communication passage 5g is connected to the connection hole 8m, and the end of the fluid communication passage 5h is connected to the connection hole 8n, so that the opening area of the connection hole 8n is reduced or closed. When it comes off, the opening areas of the fluid communication passages 5g and 5h are also narrowed or closed.

As a result, the liquid in the cylinder A chamber 5c and the cylinder B chamber 5d on both sides of the cylinder chamber 5a divided by the piston 5b smoothly moves in the fluid communication passage 5g, the variable valve 8, and the fluid communication passage 5h. The piston rod 5e cannot move smoothly in the downward direction.

Therefore, when the knee joint 9 is bent to go up or down a hill or stairs, the piston rod 5e
, A force acts in the descending direction, but the piston 5b cannot move smoothly in the descending direction of the piston rod 5e, so that bending resistance at the knee joint 9 increases, and the bending angle of the knee joint 9 becomes more than necessary. It is prevented from getting deep, and you can go up and down slopes and stairs smoothly. Also, knee breaks when walking on level ground can be prevented.

On the other hand, when the muscle at the stump is not contracted without applying weight, the first bag 6a of the first pressure sensor 6 is not pressed.

Since the first bag 6a of the first pressure sensor 6 is not pressed, the internal fluid pressure moves through the first signal path 6b, one end of which is connected to the first bag 6a, and is transmitted. Not even. Therefore, the first signal path connection reservoir 8e of the variable valve 8 to which the other end of the first signal path 6b is connected in communication.
No fluid pressure acts on the first diaphragm 8c.

Since the fluid pressure is not transmitted through the first signal path 6b to the first diaphragm 8c of the first signal path connection chamber 8e of the variable valve 8, the spool 8b is biased by the spring 8i. 8e side and the first
It has been moved to the signal path connection reservoir 8e side.

When the muscle at the stump is not contracted and the weight is applied, the first pressure sensor 6
Is pressed, and the pressure is applied to the first signal path 6.
b, the first diaphragm 8c of the first signal path connection reservoir 8e is moved to the first signal path connection side liquid reservoir 8 at a pressure P1 = W1.
Press toward f side.

When the weight is applied, the second pressure sensor 7 detects the weight, the second bag 7a of the second pressure sensor 7 is pressed, and the pressure is transmitted through the second signal path 7b. The second diaphragm 8d of the two signal path connection reservoir 8g is pressed toward the second signal path connection side liquid reservoir 8h at a pressure P2 = W2.

Thus, the pressure P1 and the pressure P2 act on the spool 8b slidably inserted into the variable valve sliding cylinder chamber 8a of the variable valve 8 from both ends.

However, the pressure difference between the pressure P1 and the pressure P2 acting on both ends of the spool 8b is smaller than the spring strength K of the spring 8i in the first signal path connection side liquid storage chamber 8f. That is, P1-P2 = (W1-W2) <K. Therefore, the spool 8b is urged toward the first signal path connection storage chamber 8e by the urging of the spring 8i, and remains moved to the first signal path connection storage chamber 8e side.

When the spool 8b is moved most toward the first signal path connection chamber 8e by the bias of the spring 8i,
The small-diameter throttle portion 8j at the center of the spool 8b is located at the connection hole 8m and the connection hole 8n, whereby the connection hole 8m and the connection hole 8n are opened to 100%.

Since the connection hole 8m and the connection hole 8n are open to 100%, the fluid communication passage 5g and the fluid communication passage 5h communicating via the connection hole 8m and the connection hole 8n are connected by 10%.
0% communication state, so that these fluid communication passages 5g,
The opening area of 5 h is not reduced.

As a result, the liquid in the cylinder A chamber 5c and the cylinder B chamber 5d on both sides of the cylinder chamber 5a divided by the piston 5b is supplied to the fluid communication passage 5g, the variable valve 8,
It can move smoothly in the fluid communication passage 5h, and the piston 5b
Can be smoothly moved in the cylinder chamber 5a even with a small force.

Therefore, when walking on a flat ground or the like, the first pressure sensor 6 and the second pressure sensor 7
When the pressure difference is less than a predetermined pressure, that is, smaller than the strength of the spring 8i, the variable valve 8 is in the fully opened state, and the piston 5b can move smoothly in the ascending and descending directions of the piston rod 5e. The resistance becomes a small resistance of only the needle valve 5i, and the lower leg 10 can be smoothly bent and stretched by the knee joint 9, so that the user can walk on flat ground or the like smoothly.

It should be noted that the present invention is not limited to the above embodiment of the present invention, and it is needless to say that various modifications can be made without departing from the spirit of the present invention. For example, in the embodiment of the present invention, the first pressure sensor 6 and the second pressure sensor 7, which detect the contraction movement of the stump end of the cutting leg, send the information to the fluid pressure to operate the variable valve 8 by transmitting the information. However, the present invention is not limited to this, and the point is that it is variable with information from the first pressure or myoelectric sensor and the second pressure or myoelectric sensor that have detected the contraction movement of the stump end of the cutting leg. Any structure may be used as long as it operates the valve 8.

[0070]

As is apparent from the above description, according to the prosthesis according to the present invention, the leg cut at a position proximal to the knee is mounted as a substitute for the leg to adjust the resistance of the knee joint to flexion and extension. The prosthesis is equipped with a hydraulic cylinder, and the movement of liquid in the cylinder chambers on both sides of the piston of the hydraulic cylinder is performed through a variable valve. On the inside surface in the socket,
A first pressure sensor for detecting a weight load and a contraction movement of a muscle at a stump of a cutting leg; a second pressure sensor for mainly detecting a weight load on a bottom surface in the thigh socket; When the pressure is higher than the pressure of the second pressure sensor by a predetermined pressure or more, the degree of throttling of the variable valve of the hydraulic cylinder that adjusts the flexion and extension resistance of the knee joint is controlled based on the pressure difference detection information between the two sensors. Thereby, the knee resistance of the prosthesis in use can be adjusted arbitrarily. As a result, an extremely novel and beneficial effect can be obtained in that the user can easily walk on stairs, slopes, and flat ground without breaking the knee of the prosthesis.

In the case of the second aspect, the weight load and the contraction movement of the muscle at the stump of the cutting leg are detected by the first bag of the first pressure sensor and are transmitted to the variable valve through the first signal path. The weight load is transmitted and detected by the second bag of the second pressure sensor and transmitted to the variable valve through the second signal path. The pressure of the first pressure sensor is higher than the pressure of the second pressure sensor on the first signal path connection side. When the strength of the spring disposed in the liquid chamber is higher than the strength of the spring, the spool in the variable valve sliding cylinder chamber moves, and the side peripheral surface of the spool is formed in the inner peripheral side surface of the variable valve sliding cylinder chamber. Is closed, the fluid communication passages respectively communicating with the cylinder chambers on both sides of the piston of the hydraulic cylinder are brought into a non-communication state through the closed connection holes, and the pressure of the first pressure sensor is changed to the second pressure sensor. When the pressure is less than or equal to the strength of the spring disposed in the first signal path connection side liquid storage chamber, both connection holes formed in the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber are opened, and the liquid is opened. The fluid communication passages respectively communicating with the cylinder chambers on both sides of the piston of the pressure cylinder can be controlled to be in communication with each other through both connection holes opened.

[Brief description of the drawings]

FIG. 1A is a side sectional view of a prosthesis showing an embodiment of the present invention. FIG. 2B is a diagram showing the relationship between the variable valve and the hydraulic cylinder shown in FIG.

FIG. 2A is a side sectional view of the prosthesis when descending the stairs according to the embodiment of the present invention. FIG. 2B is a diagram showing the relationship between the variable valve and the hydraulic cylinder shown in FIG.

FIG. 3 is a side sectional view of a hydraulic cylinder showing an embodiment of the present invention.

FIG. 4A is a cross-sectional view taken along an arrow in FIG. 4B.
FIG. 4B is a cross-sectional view taken along the arrow in FIG. 3 when the knee is bent.

FIG. 5A is a cross-sectional view taken along the arrow in FIG. 5B.
FIG. 4B is a cross-sectional view of FIG. 3 when the knee is extended.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Prosthesis 2 Thigh socket 2a Hollow part 2b Opening 3 Knee shaft 4 Foot 5 Hydraulic cylinder 5a Cylinder chamber 5b Piston 5c Cylinder A chamber 5d Cylinder B chamber 5e Piston rod 5f Extension auxiliary spring 5g Fluid communication path 5h Fluid communication path 5i Needle valve 5j Check valve 6 First pressure sensor 6a First bag 6b First signal path 7 Second pressure sensor 7a Second bag 7b Second signal path 8 Variable valve 8a Variable valve sliding cylinder chamber 8b Spool 8c 1 diaphragm 8d second diaphragm 8e first signal path connection storage chamber 8f first signal path connection side liquid storage chamber 8g second signal path connection storage chamber 8h second signal path connection side liquid storage chamber 8i spring 8j throttle unit 8k stopper 8m Connection hole 8n Connection hole 8r Communication passage 9 Knee joint 10 Lower leg

Claims (2)

[Claims] 1. A hydraulic cylinder mounted on a leg cut proximally of a knee as a substitute for the leg, for adjusting the resistance of the knee joint to flexion and extension. In the prosthesis where the movement of the liquid in the cylinder chamber is performed through a variable valve, the weight load and the muscles at the stump of the cutting leg are placed on the inner surface inside the thigh socket of the prosthesis attached to the stump of the cutting leg. A first pressure sensor for detecting a contraction movement of the subject, a second pressure sensor for mainly detecting a weight load on a bottom surface in the thigh socket, and a pressure of the first pressure sensor is a predetermined pressure higher than a pressure of the second pressure sensor. The prosthesis according to claim 1, wherein, when the height is higher, the degree of throttling of the variable valve of the hydraulic cylinder that adjusts the resistance of the knee joint to flexion and extension is controlled based on detection information of a pressure difference between the two sensors. 2. The first pressure sensor includes a first bag body provided on an inner surface in the thigh socket and a first signal path for transmitting a pressure of the first bag body to a variable valve. It comprises a second bag provided on the inner bottom surface in the thigh socket and a second signal path for transmitting the pressure of the second bag to the variable valve. The variable valve slides in the variable valve sliding cylinder chamber and the cylinder chamber. A first diaphragm and a second diaphragm attached to both ends of a spool that always protrude from both ends of a variable valve sliding cylinder chamber; a first signal path connection reservoir chamber partitioned by the first diaphragm; The first signal path connection side liquid storage chamber, the second signal path connection storage chamber partitioned by the second diaphragm, the second signal path connection side liquid storage chamber, and the first signal path connection side liquid storage chamber are disposed. The central portion of the spool that slides in the variable valve sliding cylinder chamber is formed with a narrower portion than in both sides, and the outer periphery of the throttle portion is connected to the inner peripheral surface of the variable valve sliding cylinder chamber. An internal space in which a sufficient gap is formed is formed, and on the inner peripheral side of the internal space of the variable valve sliding cylinder chamber,
2. The prosthetic limb according to claim 1, wherein connection holes for fluid communication passages respectively communicating with the cylinder chambers on both sides of the piston of the hydraulic cylinder are formed.