JP3436513B2 - Right foot - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on a leg cut proximally from the knee as a substitute for the leg, and is equipped with a hydraulic cylinder for adjusting resistance to flexion and extension of the knee joint portion. The movement of the liquid in the cylinder chambers on both sides of the piston is related to the artificial leg that passes through the variable valve.In particular, the sensor detects the contraction movement of the muscle at the stump of the amputated leg, and the fluid pressure The present invention relates to a prosthesis that can adjust the degree of squeezing of a variable valve in the cylinder to freely adjust the bending and stretching resistance of the knee of the prosthesis in use, and can walk on stairs, slopes, or flat ground without bending the knee of the prosthesis. .

[0002]

2. Description of the Related Art Conventionally, a leg that is cut proximally from the knee is mounted as a leg substitute and equipped with a pneumatic or hydraulic cylinder. The pneumatic or hydraulic cylinder is used to adjust the resistance to flexion and extension of the knee joint. Prosthetic legs that are used are known.

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

[0004]

However, this variable valve, once adjusted, is constant or only changes depending on the walking speed, and cannot be arbitrarily adjusted during wearing, and as a result, the artificial leg is used. The person was not able to flex or extend the leg in response to changes in the usage environment.

When the environment of use of the artificial leg user changes, that is, when walking downhill, the knee bends slowly while supporting the weight, and moreover, if the knee bends deeper than necessary, it is difficult to walk, and in this case, Knees should bend at a shallow angle and stop. On the other hand, when walking uphill, it is good to bend the knee to some extent, but it is necessary to prevent the knee from breaking, which may cause a fall. At the same time, when weight is applied, the resistance to bend is great, and the resistance to stretch is small. Also, when walking slowly on a flat ground, it is preferable that the knee is easily bent and stretched, and when running on a flat ground, the knee has a large resistance and it is difficult to bend and stretch the knee.

The present invention has been made in view of the above-mentioned problems and was devised to solve the problems. The object of the present invention is to cut off the stump of the cutting leg cut proximally from the knee. The contraction movement of the muscle of the prosthesis is detected by the sensor, and the resistance of the knee of the prosthesis in use is arbitrarily controlled by controlling the degree of throttling of the variable valve in the hydraulic cylinder provided on the knee of the prosthesis based on the detection information from the sensor. The purpose of the present invention is to provide a prosthesis that can be easily adjusted to walk on stairs, slopes or flat ground without breaking the knee of the prosthesis.

[0007]

In order to achieve the above object, the present invention is mounted on a leg that is cut proximal to the knee as a leg substitute, and adjusts the resistance to flexion and extension of the knee joint. In a prosthesis equipped with a hydraulic cylinder, the movement of the liquid in the cylinder chambers on both sides of the piston of the hydraulic cylinder is carried out through a variable valve.In the artificial leg, the thigh socket of the artificial leg that is attached to the stump of the cutting leg. A first pressure sensor for detecting the weight load and the contraction movement of the muscle of the stump of the amputated leg is provided on the inner side surface, and a second pressure sensor for mainly detecting the weight load is provided on the bottom surface of the 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 squeezing of the variable valve of the hydraulic cylinder that adjusts the resistance to flexion and extension of the knee joint is adjusted by the pressure difference between the two sensors. Inspection Consisting means for controlling the information.

Here, the first pressure sensor is composed of a first bag body provided on the inner surface of the thigh socket and a first signal path for transmitting the pressure of the first bag body to the variable valve, and the second pressure sensor is , Second on the inner bottom of the thigh socket
The variable valve includes a second signal path for transmitting the pressure of the bag body and the second bag body to the variable valve, and the variable valve is a variable valve sliding cylinder chamber, a spool that slides in the cylinder chamber to control a fluid flow rate, and a variable valve. A first diaphragm and a second diaphragm attached to both ends of a spool that always protrudes from both ends of the sliding cylinder chamber; a first signal path connection reservoir chamber and a first signal path connection side liquid reservoir chamber partitioned by the first diaphragm;
A second signal path connection reservoir chamber, a second signal path connection side liquid reservoir chamber, and a spring arranged in the first signal path connection side liquid reservoir chamber, which are partitioned by the second diaphragm, and are arranged in the variable valve sliding cylinder chamber. The slidable spool has a throttle part with a smaller diameter at its center than on both sides, and an internal space with a sufficient gap between the throttle part and the inner peripheral surface of the variable valve sliding cylinder chamber. Is formed, and a connection hole is formed on the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber, the connection hole for a fluid communication passage that communicates with the cylinder chambers on both sides of the piston of the hydraulic cylinder. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically based on the embodiments of the invention shown in the drawings. Here, FIG. 1 (A) is a side sectional view of the artificial leg, and FIG. 1 (B) is FIG.
FIG. 2 is a diagram showing the relationship between the variable valve and the hydraulic cylinder in FIG.
(A) is a side sectional view of the artificial leg when descending stairs, FIG. 2 (B)
Shows the relationship between the variable valve and hydraulic cylinder in Fig. 2 (A),
FIG. 3 is a side sectional view of the hydraulic cylinder, and FIG.
5B is a sectional view taken along the arrow in FIG. 4, FIG. 4B is a sectional view taken along the arrow in FIG. 3 when the knee is flexed, and FIG. 5A is a sectional view taken in the direction shown in FIG.
(B) is a cross-sectional view taken along the arrow in FIG. 3 when the knee is extended.

In the figure, a prosthesis 1 is 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 flexion and extension, It is mainly composed of a first pressure sensor 6, a second pressure sensor 7 and a variable valve 8. The lower part of the thigh socket 2 and the lower leg 10 which is the upper part of the foot part 4 are connected by a knee shaft 3, and this knee A knee joint portion 9 composed of the shaft 3, the hydraulic cylinder 5 and the variable valve 8 enables flexion and extension like a knee of a human leg.

The upper half side of the thigh socket 2 is a hollow portion 2a, and the upper end of the thigh socket 2 which is the upper end side of the hollow portion 2a is an opening 2b. From the opening 2b at this upper end. The stump of the cutting leg is inserted and mounted in the hollow portion 2a inside.

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

The inside of the cylinder chamber 5a is divided into 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 enclosed in a cylinder chamber 5a divided into two sides by a piston 5b. The liquid on both sides of the piston 5b flows in the direction opposite to 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 is extended to the outside of the hydraulic cylinder 5. In this embodiment, the hydraulic cylinder 5 is mounted vertically, the piston rod 5e is extended upward, and the upper end thereof is located slightly behind the center of rotation of the knee shaft 3 and the artificial leg 1
Is rotatably connected to a shaft mounted in the left-right direction.

An extension assisting spring 5f is provided in one side of the cylinder chamber 5a divided into two sides by the piston 5b, that is, in the cylinder A chamber 5c below the piston 5b in the drawing. The extension assisting spring 5f is urged to push the piston rod 5e upward, and the piston rod 5e of the hydraulic cylinder 5 extends upward to act in a direction in which the bent prosthesis 1 is extended.

The hydraulic cylinder 5 mounted in the lower leg 10 in the vertical direction in the drawing has the lower end side thereof at the lower leg 10.
, And is rotatably connected to a shaft mounted in the left-right direction of the artificial leg 1.

The first pressure sensor 6 detects the weight load and the contraction movement of the muscle of the stump of the cutting leg, and is placed inside the cavity 2a of the thigh socket 2 into which the stump of the cutting leg is inserted. It is provided. The first pressure sensor 6 in this embodiment has a structure that operates by fluid pressure, and the first pressure sensor 6 is composed of a first bag body 6a in which a fluid is sealed, and transmits the fluid pressure to the variable valve 8. First signal path 6b
Is provided.

The first pressure sensor 6 has a first bag body 6a.
A fluid, for example, air is sealed inside the first bag body 6a. The first bag body 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 is provided.
It is designed to come into close contact with the skin of the stump of the cutting leg inserted in a, or to make contact with a soft inner socket sandwiched therebetween.

The first signal path 6b comprises a passage such as a tube, one end of which is connected to the first bag body 6a and is in communication with the inside of the first bag body 6a.
The inside of b is filled with the same fluid as the inside of the first bag 6a. The other end of the first signal path 6b is communicatively connected to the variable valve 8.

In the first pressure sensor 6, the muscle of the stump of the cutting leg attached to the hollow portion 2a of the thigh socket 2 contracts and the weight of the muscle causes the skin of the stump of the cutting leg to have an internal surface. The first bag body 6a is pressed, 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 a 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 that operates by fluid pressure, and the second pressure sensor 7 is composed of a second bag body 7a in which a fluid is sealed, and transmits the fluid pressure to the variable valve 8. The second signal path 7b is provided.

The second pressure sensor 7 has a second bag body 7a.
A fluid, such as air, is enclosed inside the first bag body 6a. 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 is inserted into the hollow portion 2a of the thigh socket 2. Does it adhere to the skin of the stump of the amputated leg,
It is designed to come in contact with a soft inner socket.

The second signal path 7b is, for example, a tube-like path, one end of which is connected to the second bag body 7a and is in communication with the inside of the second bag body 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 7b is communicatively connected to the variable valve 8.

The second pressure sensor 7 has a second bag body 7a having an inner bottom surface of the skin of the cut end of the cut leg due to the weight load of the cut end of the cut leg attached to the hollow portion 2a of the thigh socket 2. The fluid pressure inside the pressed 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 on the pressure difference between the first pressure sensor 6 that detects the weight load and the contraction movement of the muscle of the stump of the amputated leg and the second pressure sensor 7 that mainly detects the weight load. , 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 is controlled in accordance with the moving direction of the piston 5b, and the flow rate of the liquid is controlled to control the hydraulic cylinder 5 The resistance of flexion and extension of the knee joint part 9 is adjusted by varying the resistance of the knee joint part 9.

The variable valve 8 is integrally provided on the upper portion of the hydraulic cylinder 5, and the fluid communication passage 5g and the fluid communication passage 5 are provided.
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 is moved in the piston 5b by opening and closing the connection portions of the two passages 5g and 5h provided at the connection portion with h. The flow rate of the liquid flowing in the direction opposite to the moving direction is controlled according to the direction.

The variable valve 8 is fully opened when the information from the first pressure sensor 6 and the information from the second pressure sensor 7 are balanced, 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 rate, and a spool 8b that constantly projects from both ends of the variable valve sliding cylinder chamber 8a. First diaphragm 8c and second diaphragm 8 attached to both ends of the
d, the first signal path connection reservoir chamber 8e and the first signal path connection side liquid reservoir chamber 8f, which are partitioned by the first diaphragm 8c, and the second
It is composed of a second signal path connection reservoir chamber 8g and a second signal path connection side liquid reservoir chamber 8h, which are partitioned by the diaphragm 8d, and a spring 8i arranged in the first signal path connection side liquid reservoir chamber 8f.

The variable valve sliding cylinder chamber 8a is formed laterally in the upper part of the cylinder chamber 5a, and a spool 8b is slidably inserted inside the cylinder chamber 5a. The variable valve 8 is opened and closed by moving.

The spool 8b which slides inside the variable valve sliding cylinder chamber 8a has a throttle portion 8j having a smaller diameter than the both sides at the center thereof, and the outer periphery of the throttle portion 8j at the center of the spool 8b is a variable valve. An internal space is formed with a sufficient gap between the sliding cylinder chamber 8a and the inner peripheral surface of the sliding cylinder chamber 8a. The liquid in the hydraulic cylinder 5 passes through the internal space of this gap to establish fluid communication with the fluid communication passage 5g. It has a structure of going back and forth between the passage 5h.

Further, stoppers 8k having an outer diameter larger than the inner diameter of the variable valve sliding cylinder chamber 8a are attached to both ends of the spool 8b. Within the range of the stoppers 8k at both ends, the spool 8b has a structure to move by sliding in the variable valve sliding cylinder chamber 8a.
It does not protrude from a.

On the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber 8a sealed by the spool 8b which slides inside, a connection hole 8m with the fluid communication passage 5g and a fluid communication passage 5 are provided.
Connection holes 8n with h are formed respectively. The connection hole 8n formed on the inner peripheral side surface of the internal space of the variable valve sliding cylinder chamber 8a is opened and closed by the spool 8b.

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

A first signal line connection reservoir chamber 8e which contacts the outside of a first diaphragm 8c attached to one end of the spool 8b.
Communicate with the end of the first signal path 6b. First bag 6
The pressure information of a is transmitted to the first signal path connection reservoir chamber 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 chamber 8e. To be done.

The first signal passage connecting side liquid reservoir chamber 8f which is in contact with the inside of the first diaphragm 8c attached to one end of the spool 8b has a second signal passage connecting side opposite to the variable valve sliding cylinder chamber 8a. It communicates with the liquid storage chamber 8h through a 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 reservoir 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 into the second signal path connection side liquid storage chamber 8f.
You can move to h.

In the first signal path connection side liquid storage chamber 8f,
The spring 8i is built in, and the first diaphragm 8
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, the first signal path connection side liquid storage chamber 8f side. And the spool 8b also moves to the second diaphragm 8d side.

A second signal path connection reservoir chamber 8g in contact with the outside of the second diaphragm 8d attached to the other end of the spool 8b.
Communicate with the end of the second signal path 7b. Second bag 7
The pressure information of a is transmitted to the second signal path connection reservoir chamber 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 chamber 8f. To be done. The second signal path connection reservoir chamber 8g has a space in which the second diaphragm 8d can be sufficiently moved to the chamber 8g side.

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 as described above. It communicates with the liquid storage chamber 8f on the one signal path connection side through a communication passage 8r. As the fluid, for example, the same oil as that in the cylinder chamber 5a is filled in the second signal path connection side liquid reservoir chamber 8h.

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

One end of the fluid communication passage 5g has a cylinder A chamber 5
The opening is connected to the side surface of c, and one end of the fluid communication passage 5h is connected to the side surface of the cylinder B chamber 5d. The cylinder A chamber 5c and the cylinder B chamber 5d which are divided by the piston 5b are the fluid communication passage 5g, which is variable. The valve 8 and the fluid communication passage 5h can be connected and disconnected.

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

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

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

Further, between the fluid communication passage 5g in the middle of connecting to the variable valve sliding cylinder chamber 8a and the upper side surface of the cylinder B chamber 5d, the check valve 5 opened to the fluid communication passage 5g side.
j is provided. The check valve 5j is used in the cylinder B chamber 5
The liquid can be moved to the cylinder A chamber 5c through the fluid communication passage 5g by opening when the hydraulic pressure of d becomes higher than a certain value.

Next, the operation based on the configuration of the embodiment of the present invention will be described below. Prosthesis 1 on the stump of the amputated leg
When the user walks with the thigh socket 2 on, for example, when going down the stairs, the prosthetic leg 1 touches the ground in an extended state and gradually begins to bend around the knee portion, that is, the knee axis 3 of the prosthetic leg 1.

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

When the contracting movement of the muscle of the stump of the cutting leg and the weight load act to press the first bag body 6a of the first pressure sensor 6, a part of the fluid inside the first bag body 6a. To the first signal path 6b, one end of which is communicated and connected to the first signal path 6b.

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

On the other hand, when the 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 body 7a is pressed, a part of the fluid inside moves and flows into the second signal path 7b whose one end is communicatively connected to the second bag body 7a.

Therefore, the fluid in the second signal path 7b is pressed and moves to the other end side, and the other end of the second signal path 7b is connected to the second signal path connection reservoir chamber of the variable valve 8 which is connected for communication. Part of the fluid flows into 8g to increase the pressure, and the pressure in the second signal path connection reservoir chamber 8g becomes P2. That is, pressure P2 = weight load W2.

When the pressure in the first signal path connection reservoir chamber 8e reaches the pressure P1, the first diaphragm 8c is set to the first pressure by the pressure P1.
A force that fluctuates toward the signal path connection side liquid storage chamber 8f acts. Similarly, the pressure P2 is generated in the second signal path connection reservoir chamber 8g.
Then, the second diaphragm 8d is
A force that fluctuates toward the second signal path connection side liquid storage chamber 8h side acts.

In this way, the pressure P1 and the pressure P2 act from both ends of the spool 8b slidably inserted in the variable valve sliding cylinder chamber 8a of the variable valve 8.

When the pressure difference between the pressure P1 acting on both ends of the spool 8b and the pressure P2 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 = F1 + (W1-W2)> K, the spool 8b overcomes the biasing force of the spring 8i and moves toward the second signal path connection reservoir chamber 8g.

The side surface of the spool 8b moving toward the second signal path connection reservoir chamber 8g side narrows or closes the opening area of the connection hole 8n opened at 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 narrowed or closed. When it is peeled off, the opening areas of the fluid communication passages 5g and 5h are also narrowed or blocked.

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. Since it becomes impossible, the piston rod 5e cannot move smoothly in the descending direction.

Therefore, when the knee joint portion 9 is bent for going up and down a slope or stairs, the piston rod 5e
However, since the piston 5b cannot move smoothly in the descending direction of the piston rod 5e, the bending resistance at the knee joint portion 9 becomes large, and the bending angle of the knee joint portion 9 becomes larger than necessary. It prevents it from getting deeper and allows you to smoothly climb up and down slopes and stairs. Also, it is possible to prevent the knee from being broken when walking on a flat ground.

On the other hand, when the muscle of 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 body 6a of the first pressure sensor 6 is not pressed, the internal fluid pressure is transferred by being moved in the first signal path 6b, one end of which is connected to the first bag body 6a. Nothing. Therefore, the first signal path connection reservoir chamber 8e of the variable valve 8 to which the other end of the first signal path 6b is communicatively connected.
The fluid pressure does not act on the first diaphragm 8c.

Since fluid pressure is not transmitted to the first diaphragm 8c of the first signal path connection reservoir chamber 8e of the variable valve 8 through the first signal path 6b, the spool 8b is urged by the spring 8i so that the first signal path connection reservoir chamber. The most urged to the 8e side
It remains moved to the signal path connection reservoir chamber 8e side.

When the muscle of the stump is not contracted and the weight is heavy, the first pressure sensor 6
The first bag body 6a of the
b through the first diaphragm 8c of the first signal path connection reservoir chamber 8e at the pressure P1 = W1 to the first signal path connection side liquid reservoir chamber 8e.
Press toward f side.

When the weight is applied, it is detected by the second pressure sensor 7, the second bag body 7a of the second pressure sensor 7 is pressed, and the pressure is transmitted through the second signal path 7b to the second pressure path 7b. The second diaphragm 8d of the 2-signal path connection reservoir chamber 8g is pressed toward the second signal path connection side liquid reservoir chamber 8h side at a pressure P2 = W2.

In this way, the pressure P1 and the pressure P2 act from both ends of the spool 8b slidably inserted in the variable valve sliding cylinder chamber 8a of the variable valve 8.

However, the pressure difference between the pressures P1 and 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 biased toward the first signal path connection reservoir chamber 8e by the biasing force of the spring 8i, and is still moved to the first signal path connection reservoir chamber 8e side.

When the spool 8b is moved to the first signal path connection reservoir chamber 8e side by the bias of the spring 8i,
A 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 open at 100%.

Since the connection hole 8m and the connection hole 8n are opened to 100%, the fluid communication passage 5g and the fluid communication passage 5h which communicate with each other through the connection hole 8m and the connection hole 8n are 10
There is 0% communication, so these fluid communication passages 5g,
The opening area of 5h is not narrowed.

As a result, the liquids 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 are the fluid communication passage 5g, the variable valve 8,
It can move smoothly in the fluid communication passage 5h, and the piston 5b
Also, it is possible to smoothly move in the cylinder chamber 5a even with a weak force.

Therefore, when walking normally on a flat ground, the first pressure sensor 6 and the second pressure sensor 7
When the pressure difference between and is less than a predetermined pressure, that is, less 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, so that the knee joint portion 9 can smoothly bend and extend the lower leg portion 10, and can walk smoothly on a flat ground or the like.

The present invention is not limited to the embodiments of the present invention described above, and it goes without saying that various modifications can be made without departing from the spirit of the present invention. For example, in the embodiment of the invention described above, the structure in which the first pressure sensor 6 and the second pressure sensor 7 which detect the contraction movement of the stump of the cutting leg make the fluid pressure to send information and operate the variable valve 8 However, the present invention is not limited to this, and the point is that it is changed by the information from the first pressure or myoelectric sensor and the second pressure or myoelectric sensor that detect the contraction movement of the stump of the amputated 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 artificial leg according to the present invention, the leg cut off proximal to the knee is mounted as a substitute for the leg, and the resistance to flexion and extension of the knee joint is adjusted. In the artificial leg, which is equipped with a hydraulic cylinder that moves the liquid in the cylinder chambers on both sides of the piston of the hydraulic cylinder through a variable valve, the thigh of the artificial leg attached to the stump of the cutting leg. On the inside surface of the socket,
A first pressure sensor that detects the weight load and the contraction movement of the muscle of the stump of the amputated leg is provided, and a second pressure sensor that mainly detects the weight load is provided on the bottom surface of the thigh socket. When the pressure is higher than the pressure of the second pressure sensor by a predetermined pressure or more, the throttling degree of the variable valve of the hydraulic cylinder that adjusts the resistance to flexion and extension of the knee joint is controlled by the detection information of the pressure difference between the both sensors. Thereby, the resistance of the knee of the prosthesis in use can be arbitrarily adjusted. As a result, there is an extremely new and beneficial effect that it is possible to walk easily on stairs, slopes, and flat ground without bending the knee of the artificial leg.

According to the second aspect of the present invention, the weight bearing and the contraction movement of the muscle of the stump of the amputated leg are detected by the first bag of the first pressure sensor and are changed to the variable valve through the first signal path. Then, the weight load is detected by the second bag of the second pressure sensor and transmitted to the variable valve through the second signal path, and the pressure of the first pressure sensor is closer to the first signal path connection side than the pressure of the second pressure sensor. When the strength of the spring arranged in the liquid storage 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 a connection hole formed on the inner peripheral side surface of the variable valve sliding cylinder chamber. Closed to make the fluid communication passages that communicate with the cylinder chambers on both sides of the piston of the hydraulic cylinder sandwiched between the fluid communication passages and the fluid communication passages that are not connected to each other through the closed connection holes, and the pressure of the first pressure sensor is the second pressure sensor. When the pressure is below the strength of the spring arranged 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 to It is possible to control by making the fluid communication passages, which communicate with the cylinder chambers on both sides of the piston of the pressure cylinder, respectively, open through both connection holes.

[Brief description of drawings]

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

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

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

FIG. 4A is a sectional view taken along the arrow in FIG. 4B.
(B) is a cross-sectional view taken along the arrow in FIG. 3 when the knee is flexed.

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

[Explanation of symbols]

1 artificial leg 2 thigh socket 2a hollow part 2b opening 3 knee axes 4 feet 5 hydraulic cylinder 5a cylinder chamber 5b piston 5c Cylinder A room 5d cylinder B room 5e Piston rod 5f Extension assist spring 5g fluid communication passage 5h fluid communication passage 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 valves 8a Variable valve sliding cylinder chamber 8b spool 8c 1st diaphragm 8d Second diaphragm 8e 1st signal path connection reservoir 8f 1st signal path connection side liquid reservoir 8g Second signal path connection reservoir 8h Second signal path connection side liquid reservoir 8i spring 8j throttle 8k stopper 8m connection hole 8n connection hole 8r communication passage 9 Knee joint 10 Lower leg

Claims (2)

(57) [Claims] 1. A hydraulic cylinder that is attached to a leg cut proximally from the knee as a substitute for the leg and that adjusts the resistance to flexion and extension of the knee joint portion is equipped with both sides of the piston of the hydraulic cylinder. The movement of the liquid in the cylinder chamber of the prosthesis is carried out through a variable valve.In the prosthesis that is attached to the stump of the cutting leg, the weight load and the muscles of the stump of the cutting leg are attached to the inner surface of the prosthesis The first pressure sensor for detecting the contraction movement of the person is provided, and the second pressure sensor for mainly detecting the weight load is provided on the bottom surface of the thigh socket. The pressure of the first pressure sensor is a predetermined pressure higher than the pressure of the second pressure sensor. When it is higher than the above, the prosthesis is characterized in that the degree of throttling of the variable valve of the hydraulic cylinder for adjusting the resistance to flexion and extension of the knee joint is controlled by the detection information of the pressure difference between the both sensors. 2. The first pressure sensor comprises a first bag body provided on the inner surface of the thigh socket and a first signal path for transmitting the pressure of the first bag body to a variable valve, and the second pressure sensor comprises: It comprises a second bag provided on the inner bottom surface of 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. And a first diaphragm and a second diaphragm attached to both ends of the spool that constantly protrudes from both ends of the variable valve sliding cylinder chamber, and 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 side liquid 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 arranged. The spool that slides in the variable valve sliding cylinder chamber is formed with a throttle part with a smaller diameter in the center than on both sides. An inner space with a sufficient gap is formed between the inner space and the inner surface of the inner space of the variable valve sliding cylinder chamber.
2. The artificial leg according to claim 1, wherein connection holes for forming fluid communication passages that communicate with the cylinder chambers on both sides of the piston of the hydraulic cylinder are provided.