Novel servo air pressure artificial limb knee joint

Abstract

The invention provides a novel servo air pressure prosthetic knee joint, and relates to the field of prosthetic knee joints, the novel servo air pressure prosthetic knee joint is characterized in that an upper air chamber and a lower air chamber are arranged in a cylinder body, and the upper air chamber and the lower air chamber are respectively provided with an upper piston and a lower piston; the first throttling valve and the second throttling valve each comprise a valve body, the end, close to a valve rod of the valve element, of each valve body is provided with a first opening, the side wall of each valve body is provided with a second opening communicated to the inner cavity, and the inner cavity is provided with a valve sleeve which is attached to the inner wall of the valve body and can move left and right. The body of the valve sleeve is provided with a through hole allowing a valve rod of the valve element to penetrate through and a throttling channel communicated with the through hole and the inner cavity, and the valve rod is further sleeved with an adjusting spring. And when the knee joint of the artificial limb is in a zero position, the throttling port at the joint of the throttling channel and the through hole is blocked by the valve rod part of the valve core. The artificial limb knee joint is simple in structure, damping self-adaptive adjustment of the artificial limb knee joint is achieved, and an artificial limb can follow the gait of the healthy side in real time.

Description

Technical Field

[0001] The present invention relates to the field of prosthetic knee joints, and in particular to a novel servo-pneumatic prosthetic knee joint. Background Art

[0002] Due to work-related injuries, traffic accidents, diseases, natural disasters, and force majeure, the demand for prosthetic limbs among amputees is gradually increasing. With the continuous improvement of my country's economic level and technological progress, amputees have higher and higher requirements for the performance of prosthetic limbs.

[0003] Although there are pneumatic prosthetic knee joints in China at present, due to the inability to adaptively adjust the damping performance of the prosthetic knee joint, the required prosthetic swing speed cannot automatically follow the healthy side swing speed requirements, which is very inconvenient for patients to use, and cannot achieve the bionic characteristics of the human body's natural gait and the safety requirements of exercise.

[0004] There are also some prosthetic knee joint devices in the prior art, such as the authorization announcement number CN103271783B, the invention name: A Chinese authorized invention of a prosthetic knee joint with power-assistance function, and the authorization announcement number CN113244028B, the invention name: A Chinese authorized invention of a throttle valve damping wearable robot joint drive device. They are often achieved by setting up a power device such as a motor, and then driving the throttle valve to change the flow rate according to the corresponding sensor and control device. On the one hand, the structure is complex and the cost is high. On the other hand, there is a certain lag in the calculation and processing method through the control device, and the adaptability also needs to be improved.

[0005] Therefore, a new type of servo-pneumatic prosthetic knee joint is needed to at least partially solve the above technical problems. Summary of the Invention

[0006] The embodiment of the present invention provides a novel servo-pneumatic prosthetic knee joint with a simple structure, which realizes adaptive damping adjustment of the prosthetic knee joint, so that the prosthesis can follow the gait of the healthy side in real time.

[0007] The present invention provides a novel servo-pneumatic prosthetic knee joint, the prosthetic knee joint comprising:

[0008] A cylinder body, wherein the interior of the cylinder body has a relatively sealed upper air chamber and a lower air chamber, wherein the upper air chamber and the lower air chamber are respectively provided with an upper piston and a lower piston connected by the same piston rod and can move up and down synchronously under the action of an external force;

[0009] A first throttle valve and a second throttle valve are provided in the housing of the cylinder body, each of the first throttle valve and the second throttle valve comprising a valve body including an inner cavity, a valve core being axially provided in the valve body, a first opening being formed at one end of a valve stem adjacent to the valve core, a second opening being provided on a side wall of the valve body connected to the inner cavity, a valve sleeve being provided in the inner cavity and being adapted to move leftward and rightward relative to the valve body and being fitted to the inner wall of the valve body, the valve sleeve comprising a body, a through hole being provided in the body for the valve stem of the valve core to pass through, and a throttling passage connecting the through hole and the inner cavity; wherein the valve stem of the valve core is further provided with a regulating spring, the two ends of which are respectively connected to the body and the valve body;

[0010] The first throttle valve is connected to the lower air chamber in a one-way manner through the upper air chamber, the first opening, and the second opening in sequence; the second throttle valve is connected to the upper air chamber in a one-way manner through the lower air chamber, the second opening, and the first opening in sequence;

[0011] When the prosthetic knee joint is in the neutral position, the throttle openings at the junctions of the throttle passages and the through-holes of the first and second throttle valves are partially blocked by the valve stems of the valve cores. This technical feature enables the first and second throttle valves to reduce or increase the actual throttle openings for gas flow as the prosthetic knee joint flexes or extends, respectively, thereby achieving the necessary technical features for adaptively increasing or decreasing damping.

[0012] According to the prosthetic knee joint of the present invention, when the prosthetic knee joint starts to flex from the zero position, the upper piston and the lower piston move downward under the action of an external force, for example, by turning the rotating member relative to the cylinder body and driving the upper piston and the lower piston downward by pressing the crank, the space in the upper air chamber gradually becomes smaller, and the gas flows into the lower air chamber through the air path of the first throttle valve and the first one-way valve. In this process, the valve sleeve of the first throttle valve forms a barrier to the gas except for the through hole and the throttle channel for gas to pass through. Therefore, the gas pushes the valve sleeve of the first throttle valve to move rightward relative to the valve body (valve stem), so that the area of ​​the throttle port at the connection between the throttle channel and the through hole blocked by the valve stem becomes larger, that is, the throttle port actually for gas to pass through becomes smaller, the flexion damping increases, and the flexion angle becomes smaller; when the prosthetic knee joint completes the flexion movement and starts to extend, the upper piston and the lower piston move upward under the action of external force. At this time, the space in the lower air chamber gradually becomes smaller, and the upper air chamber is in a negative pressure state. The gas in the lower air chamber passes through the second throttle valve and the second one-way valve. The air path flows toward the upper air chamber. During this process, the valve sleeve of the second throttle valve forms a barrier to the gas in addition to the through-hole and the throttle channel for gas to pass through. Therefore, the gas pushes the valve sleeve of the second throttle valve to move leftward relative to the valve body (valve stem), so that the area of ​​the throttle opening at the connection between the throttle channel and the through-hole is blocked by the valve stem, that is, the throttle opening actually allowing gas to pass through is increased, and the extension damping is reduced. According to the prosthetic knee joint of the present invention, an important innovation lies in the improvement of the structure of the first throttle valve and the second throttle valve. Based on the improvement of its own structure, the throttle valve flow rate can be adaptively changed. Compared with the existing technology that uses power devices such as motors, sensors and control devices to drive the throttle valve to change the flow rate, the structure is greatly simplified and the cost is significantly reduced. There is also no certain hysteresis problem caused by the calculation and processing method of the control device. Based on this, the damping adaptive adjustment is achieved through the rotating part, cylinder body, crank, first throttle valve, second throttle valve and other structures, which can dynamically and adaptively follow the gait of the healthy side in real time.

[0013] Optionally, the piston rod further has an inner hole extending in the axial direction, the top end of the inner hole is connected to the outside, and the bottom end of the inner hole is connected to the lower air chamber via a through hole.

[0014] According to this solution, an inner hole extending in the axial direction is further provided through the piston rod, so that the prosthetic knee joint can perform flexion and extension movements more smoothly.

[0015] In a second aspect, the present invention further provides a lower limb prosthesis, comprising a prosthetic knee joint according to the above technical solution.

[0016] Additional advantages, objects, and features of the present invention will be set forth in part in the following description and will become apparent to those skilled in the art upon examination of the following or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structures particularly pointed out in the description and drawings.

[0017] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are intended to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are merely for the purpose of illustrating the principles of the present invention. To facilitate the illustration and description of certain portions of the present invention, corresponding portions in the drawings may be exaggerated, that is, may be larger than other components in an exemplary device actually manufactured according to the present invention. In the drawings:

[0019] Figure 1 is a schematic diagram of the internal structure of a prosthetic knee joint according to an embodiment of the present invention;

[0020] Figure 2 is a side view of a prosthetic knee joint according to an embodiment of the present invention;

[0021] Figure 3 FIG1 is a schematic diagram of a first throttle valve in a prosthetic knee joint according to an embodiment of the present invention, wherein the first throttle valve is a schematic diagram of a state in which the prosthetic knee joint is in a zero position; ...

[0022] Figure 4 is a schematic diagram of another state of the first throttle valve in the prosthetic knee joint according to an embodiment of the present invention, in which the first throttle valve is in a state where the valve sleeve moves to the right to the extreme position relative to the valve body;

[0023] Figure 5 is a schematic diagram of a second throttle valve in a prosthetic knee joint according to an embodiment of the present invention, wherein the second throttle valve is in a state where the valve sleeve moves leftward relative to the valve body until it abuts against the pin shaft;

[0024] Figure 6 is a schematic diagram of the internal structure of a cylinder in a prosthetic knee joint according to an embodiment of the present invention; and

[0025] Figure 7 Schematic diagram of the relative position distribution among the first rotation axis, the second rotation axis, the third rotation axis and the fourth rotation axis in a prosthetic knee joint according to an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 100. Prosthetic knee joint;

[0028] 110. Rotating parts;

[0029] 120, cylinder body; 121, piston rod; 122, inner hole; 123, upper piston; 124, lower piston; 125, return spring; 126, partition;

[0030] 131. crank; 132. connecting arm; 133. connecting frame;

[0031] 141. First throttle valve; 142. Second throttle valve; 143. Valve body; 144. Valve core; 1441. Valve stem; 145. First opening; 146. Second opening; 147. Valve sleeve; 1471. Through hole; 1472. Throttle passage; 1473. Throttle port; 148. Adjusting spring; 149. Pin;

[0032] 151, first rotating shaft; 152, second rotating shaft; 153, third rotating shaft; 154, fourth rotating shaft;

[0033] 160, four-sided platform;

[0034] 170. Clamping parts. DETAILED DESCRIPTION

[0035] The objects and functions of the present invention, as well as methods for achieving these objects and functions, will be clarified with reference to exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The essence of the description is merely to help those skilled in the relevant art to comprehensively understand the specific details of the present invention.

[0036] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0037] Ordinal numbers such as "first" and "second" cited in the present invention are merely identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of a "second component", and the term "second component" itself does not imply the existence of a "first component".

[0038] It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and similar expressions used in this document are for illustrative purposes only and are not limiting.

[0039] The present invention provides a novel servo-pneumatic prosthetic knee joint 100. The prosthetic knee joint 100 can be used in the field of rehabilitation assistive devices, such as prosthetic knee joints, to solve the problem of existing prosthetic knee joints being unable to adaptively adjust the swing speed to match the swing speed of the healthy side.

[0040] There are also some prosthetic knee joint devices in the prior art, such as the authorization announcement number CN103271783B, the invention name: A Chinese authorized invention of a prosthetic knee joint with power-assistance function, and the authorization announcement number CN113244028B, the invention name: A Chinese authorized invention of a throttle valve damping wearable robot joint drive device. They are often achieved by setting up a power device such as a motor, and then driving the throttle valve to change the flow rate according to the corresponding sensor and control device. On the one hand, the structure is complex and the cost is high. On the other hand, there is a certain lag in the calculation and processing method through the control device, and the adaptability also needs to be improved.

[0041] In order to solve the above problems, the present invention provides a novel servo-pneumatic prosthetic knee joint 100. In a preferred embodiment, as Figure 1 、 Figure 3 and Figure 6 As shown, Figure 1 is a schematic diagram of the internal structure of a prosthetic knee joint according to an embodiment of the present invention; Figure 3 FIG1 is a schematic diagram of a first throttle valve in a prosthetic knee joint according to an embodiment of the present invention, wherein the first throttle valve is a schematic diagram of a state in which the prosthetic knee joint is in a zero position; ... Figure 6 FIG. 1 is a schematic diagram of the internal structure of a cylinder in a prosthetic knee joint according to an embodiment of the present invention. The prosthetic knee joint 100 may include a cylinder 120 , a first throttle valve 141 , and a second throttle valve 142 .

[0042] The cylinder 120 is used to realize the flow of gas, thereby generating damping. The first throttle valve 141 and the second throttle valve 142 are used to adjust the damping level when the prosthetic knee joint 100 performs flexion and extension movements.

[0043] Specifically, the cylinder body 120 at the bottom extends in the vertical direction. The interior of the cylinder body 120 has a relatively sealed upper air chamber and a lower air chamber. The upper air chamber and the lower air chamber are respectively provided with an upper piston 123 and a lower piston 124 connected by the same piston rod 121 and can move up and down synchronously under the action of an external force. Among them, the two ends of the piston rod 121 can be threadedly connected to the upper piston 123 and the lower piston 124 respectively. The bottom of the lower piston 124 can be connected to the bottom cover of the cylinder body 120 via a return spring 125. The return spring 125 can help the upper piston 123, the lower piston 124 and the piston rod 121 to reset. Among them, the upper air chamber and the lower air chamber are not air chambers fixed in space, and they will change as the upper piston 123 and the lower piston 124 move.

[0044] The upper piston 123 and the lower piston 124 can move up and down synchronously under the action of an external force, which can be achieved through the rotating member 110 and the crank 131.

[0045] The top structure is a rotating member 110 that can be tilted forward and backward relative to the cylinder body 120. Rotating member 110 is rotatably connected to the upper piston 123 via a crank 131. Crank 131 is used to drive the up and down movement of piston rod 121. Rotating member 110 is a common structure in prosthetic knee joint 100, used to connect to the thigh end rod. It can adopt an existing structure and will not be described in detail here.

[0046] In order to realize connection with the thigh end rod, a quadrangular platform 160 is also provided on the top of the rotating member 110. The quadrangular platform 160 can be installed in the quadrangular platform 160 by a threaded connection mode, so as to realize quick disassembly and assembly.

[0047] The prosthetic knee joint 100 according to the present invention may further include a multi-link mechanism. The upper and lower ends of the multi-link mechanism are rotatably connected to the housings of the rotating member 110 and the cylinder 120, respectively, to enable the rotating member 110 to flip forward and backward relative to the cylinder 120. The specific type of the multi-link mechanism is not limited. For example, the multi-link mechanism may include a connecting arm 132 and a connecting frame 133.

[0048] Specifically, the upper end of connecting arm 132 is rotatably connected to the front side of rotating member 110 via first rotating shaft 151. The lower end of connecting arm 132 is rotatably connected to the upper front side of the housing of cylinder body 120 via fourth rotating shaft 154. Preferably, prosthetic knee joint 100 may include two connecting arms 132. The two connecting arms 132 are symmetrically arranged on both sides of the housing of rotating member 110 and cylinder body 120.

[0049] The upper end of the connecting frame 133 is rotatably connected to the rear side of the rotating member 110 via the second rotating shaft 152. The lower end of the connecting frame 133 is rotatably connected to the upper rear side of the housing of the cylinder body 120 via the third rotating shaft 153. For example, the connecting frame 133 can be an H-shaped connecting frame 133.

[0050] The first rotating shaft 151 , the second rotating shaft 152 , the third rotating shaft 153 and the fourth rotating shaft 154 are arranged in parallel. Thus, the combination of the rotating member 110 , the connecting arm 132 , the cylinder 120 and the connecting frame 133 forms a four-bar linkage of the prosthetic knee joint 100 .

[0051] The top end of the crank 131 is rotatably connected to the rotating member 110 , and the bottom end of the crank 131 is rotatably connected to the upper piston 123 , so as to drive the upper piston 123 and the lower piston 124 to move up and down synchronously when the rotating member 110 flips forward and backward.

[0052] A first throttle valve 141 and a second throttle valve 142 are provided in the housing of the cylinder body 120. The first throttle valve 141 and the second throttle valve 142 each include a valve body 143 containing an inner cavity. A valve core 144 is axially arranged in the valve body 143. A first opening 145 is provided at one end of the valve body 143 near the valve stem 1441 of the valve core 144. A second opening 146 connected to the inner cavity is provided on the side wall of the valve body 143. A valve sleeve 147 is provided in the inner cavity and is attached to the inner wall of the valve body 143 and can move left and right relative to the valve body 143. For example, the valve sleeve 147 can be made of copper. The valve sleeve 147 can include a cylindrical body. The body is provided with a through hole 1471 for the valve stem 1441 of the valve core 144 to pass through, and a throttling channel 1472 connecting the through hole 1471 and the inner cavity. The valve stem 1441 of the valve core 144 is also sleeved with an adjustment spring 148 whose two ends are respectively connected to the main body and the valve body 143.

[0053] The first opening 145 of the first throttle valve 141 is connected to the upper air chamber. The second opening 146 of the first throttle valve 141 can be connected to the lower air chamber via a first one-way valve. The first one-way valve is open only when gas flows from the upper air chamber through the first opening 145 and the second opening 146 to the lower air chamber. The first opening 145 of the second throttle valve 142 is connected to the upper air chamber via a second one-way valve in the opposite direction. The second opening 146 of the second throttle valve 142 is connected to the lower air chamber. The second one-way valve is open only when gas flows from the lower air chamber through the second opening 146 and the first opening 145 to the upper air chamber.

[0054] Among them, reference Figure 3 When the prosthetic knee joint 100 is at zero position, the throttle port 1473 at the connection between the throttle channel 1472 and the through hole 1471 of the first throttle valve 141 and the second throttle valve 142 is partially blocked by the valve stem 1441 of the valve core 144. Figure 3 Schematic diagram of the state of the first throttle valve 141 at this time is shown in FIG, which also represents the state of the second throttle valve 142 at this time.

[0055] According to the above technical solution, the working process of the prosthetic knee joint 100 of the present invention is as follows:

[0056] refer to Figure 4 When the prosthetic knee joint 100 starts to flex from the zero position, the rotating part 110 flips relative to the cylinder body 120, and drives the upper piston 123 and the lower piston 124 to move downward by pressing the crank 131. The space in the upper air chamber gradually becomes smaller, and its gas flows to the lower air chamber through the first throttle valve 141 and the air path of the first one-way valve (in the first throttle valve 141, the gas flows from the first opening 145 to the second opening 146). During this process, in addition to the through hole 1471 and the throttling channel 1472 of the valve sleeve 147 of the first throttle valve 141 for gas to pass through, the valve sleeve 147 (left end face) of the first throttle valve 141 forms a barrier to the gas, so that the gas pushes the valve sleeve 147 of the first throttle valve 141 to move to the right relative to the valve body 143 (valve stem 1441), so that the area of ​​the throttle port 1473 at the connection between the throttling channel 1472 and the through hole 1471 blocked by the valve stem 1441 becomes larger, that is, the actual throttle port 1473 for gas to pass through becomes smaller, the flexure damping increases, and the flexure angle becomes smaller. Of course, when the valve sleeve 147 of the first throttle valve 141 moves rightward to its limit relative to the valve body 143, the throttle opening 1473 at the junction of the throttle channel 1472 and the through hole 1471 remains connected due to the resistance of the adjustment spring 148, ensuring gas flow. However, the throttle opening 1473 is smaller than when the prosthetic knee joint 100 is in the zero position. Thus, the first throttle valve 141 is responsible for adaptive adjustment of the flexion damping. After the flexion of the prosthetic knee joint 100 is completed, the valve sleeve 147 of the first throttle valve 141 can be reset.

[0057] Then, refer to Figure 5When the prosthetic knee joint 100 completes the flexion movement and starts to extend, the upper piston 123 and the lower piston 124 can move upward under the action of the rebound of the return spring 125 and the upward pulling of the crank 131. At this time, the space in the lower air chamber gradually becomes smaller, and the upper air chamber is in a negative pressure state. The gas in the lower air chamber flows to the upper air chamber through the second throttle valve 142 and the air path of the second one-way valve (in the second throttle valve 141, the gas flows from the second opening 146 to the first opening 145). During this process, the valve sleeve 147 of the second throttle valve 142, in addition to the through hole 1471 and the throttle channel 1472 for gas to pass through, forms a barrier to the gas in the valve sleeve 147 (right end face) of the second throttle valve 142. Therefore, the gas pushes the valve sleeve 147 of the second throttle valve 142 to move to the left relative to the valve body 143 (valve stem 1441), so that the area of ​​the throttle opening 1473 at the connection between the throttle channel 1472 and the through hole 1471 blocked by the valve stem 1441 becomes smaller, that is, the throttle opening 1473 actually for gas to pass through becomes larger, and the extension damping is reduced. It can be seen that the second throttle valve 142 is responsible for the adaptive adjustment of the extension damping. Among them, when the extension movement of the prosthetic knee joint 100 is completed, the valve sleeve 147 of the second throttle valve 142 can be reset.

[0058] Therefore, the prosthetic knee joint 100 according to the present invention can realize adaptive damping adjustment, and can dynamically and adaptively follow the healthy side gait in real time, thereby achieving the bionic characteristics of the natural gait of the human knee joint and the requirements of sports safety, and effectively improving the following performance of the prosthetic limb and the healthy side gait.

[0059] In order to more reasonably install the first throttle valve 141 and the second throttle valve 142, the middle of the cylinder body 120 further has a partition 126. The first throttle valve 141 and the second throttle valve 142 can be embedded in the partition 126 side by side along the radial direction of the cylinder body 120 through clearance fit. Figure 2 The ends of the valve bodies 143 of the first throttle valve 141 and the second throttle valve 142 away from the first opening 145 both abut against the pressing member 170 located in the middle. That is, the pressing member 170 presses the ends of the valve bodies 143 of the first throttle valve 141 and the second throttle valve 142 away from the first opening 145 to secure the throttle valves. The pressing member 170 is not limited to a specific type and can be, for example, a screw.

[0060] Furthermore, the cylinder body 120 can be open at the top and closed at the bottom. The upper air chamber can be enclosed by the upper piston 123, the partition 126, and the shell of the cylinder body 120. The partition 126 can be an integral structure with the shell of the cylinder body 120, or a separate structure. The piston rod 121 vertically penetrates the partition 126.

[0061] refer to Figure 6In the illustrated embodiment, piston rod 121 further includes an axially extending inner hole 122. The top end of inner hole 122 is connected to the outside atmosphere. The bottom end of inner hole 122 is connected to the lower air chamber via a through hole. The provision of axially extending inner hole 122 in piston rod 121 allows for smoother flexion and extension of prosthetic knee joint 100.

[0062] refer to Figure 5 The valve bodies 143 of the first throttle valve 141 and the second throttle valve 142 are also provided with a radially extending limit pin 149 at the first opening 145, so that when the valve sleeve 147 abuts against the pin 149 to the left, the valve sleeve 147 is still sleeved on the valve stem 1441 of the corresponding valve core 144.

[0063] In a preferred embodiment, reference Figure 7 The distance between the first rotating axis 151 and the second rotating axis 152 is a first length L1. The distance between the second rotating axis 152 and the third rotating axis 153 is a second length L2. The distance between the third rotating axis 153 and the fourth rotating axis 154 is a third length L3. The distance between the fourth rotating axis 154 and the first rotating axis 151 is a fourth length L4.

[0064] The second, third, and fourth lengths are all greater than the first length. The first, second, and third lengths are all less than the fourth length. The sum of the second and third lengths is less than the sum of the first and fourth lengths. For example, the first length may be 28.4 mm, the second length may be 51.9 mm, the third length may be 56.9 mm, and the fourth length may be 114.7 mm.

[0065] And, continue to refer to Figure 7 A coordinate system is established with the center of fourth rotation axis 154 as the origin. When prosthetic knee joint 100 is at zero position, the angle α between the center line of first rotation axis 151 and second rotation axis 152 and the horizontal line is 45.5°. The angle β between the center line of third rotation axis 153 and fourth rotation axis 154 and the horizontal line is -45.9°.

[0066] Through the above design, the instantaneous center curve of the four-bar linkage mechanism in the prosthetic knee joint 100 (i.e., the combination of the rotating part 110, the connecting arm 132, the cylinder 120 and the connecting frame 133) coincides with the instantaneous center trajectory of the human knee joint, thereby making the gait of the prosthetic knee joint 100 of the present invention more consistent with the natural gait characteristics of the human body.

[0067] Furthermore, the position where the crank 131 is connected to the rotating member 110 may be located behind the first rotating shaft 151 and above the second rotating shaft 152 .

[0068] In a second aspect, the present invention further provides a lower limb prosthesis (not shown), which includes the prosthetic knee joint 100 of the above embodiment. Therefore, the lower limb prosthesis according to the present invention includes all the features and effects of the prosthetic knee joint 100 according to the present invention, which will not be repeated here.

[0069] Other embodiments of the present invention will be readily apparent to those skilled in the art from the description and practice of the invention disclosed herein. The description and embodiments are intended to be exemplary only, and the true scope and spirit of the present invention are defined by the claims.

Claims

1. A new type of servo-pneumatic prosthetic knee joint, characterized in that: The prosthetic knee joint comprises: A cylinder body having relatively sealed upper and lower air chambers inside, wherein the upper and lower air chambers are respectively provided with an upper piston and a lower piston connected by the same piston rod and capable of synchronously moving up and down under the action of an external force; a first throttle valve and a second throttle valve provided to the housing of the cylinder body, the first throttle valve and the second throttle valve both comprising a valve body with a valve core axially arranged in an inner cavity, the valve body having a first opening at one end of a valve stem close to the valve core, a second opening connected to the inner cavity provided on a side wall of the valve body, the inner cavity being provided with a valve sleeve fitted to the inner wall of the valve body and movable leftward and rightward relative to the valve body, the body of the valve sleeve being provided with a through hole for the valve stem of the valve core to pass through, and a throttling channel connecting the through hole and the inner cavity, the valve stem sleeve of the valve core being provided with an adjusting spring connected at both ends to the body and the valve body respectively; The first throttle valve is connected to the lower air chamber in a one-way manner through the upper air chamber, the first opening, and the second opening in sequence; the second throttle valve is connected to the upper air chamber in a one-way manner through the lower air chamber, the second opening, and the first opening in sequence; When the prosthetic knee joint is at zero position, the throttle openings at the connection between the throttle channels and the through holes of the first throttle valve and the second throttle valve are partially blocked by the valve stems of the corresponding valve cores.

2. The prosthetic knee joint according to claim 1, wherein: The piston rod further has an inner hole extending in the axial direction, the top end of the inner hole is connected to the outside, and the bottom end of the inner hole is connected to the lower air chamber via a through hole.

3. The prosthetic knee joint according to claim 1, wherein: The valve bodies of the first throttle valve and the second throttle valve are further provided with radially extending limiting pins at the first openings, so that the valve sleeves are still sleeved on the valve stems of the corresponding valve cores when they abut against the pins to the left; and / or The prosthetic knee joint further includes a rotating member configured to be flippable in a front-to-rear direction relative to the cylinder body, and the rotating member is rotatably connected to the upper piston via a crank.

4. The prosthetic knee joint according to claim 3, wherein: The prosthetic knee joint further includes a multi-rod connection mechanism for realizing the flipping of the rotating member relative to the cylinder body in the front-to-back direction, the multi-rod connection mechanism comprising: a connecting arm, wherein the upper end of the connecting arm is rotatably connected to the front side of the rotating member via a first rotating shaft, and the lower end of the connecting arm is rotatably connected to the upper front side of the housing of the cylinder body via a fourth rotating shaft; a connecting frame, wherein the upper end of the connecting frame is rotatably connected to the rear side of the rotating member via a second rotating shaft, and the lower end of the connecting frame is rotatably connected to the upper rear side of the shell of the cylinder body via a third rotating shaft; Wherein, the first rotating shaft, the second rotating shaft, the third rotating shaft and the fourth rotating shaft are arranged in parallel.

5. The prosthetic knee joint according to claim 4, characterized in that: The distance between the first rotating axis and the second rotating axis is the first length, the distance between the second rotating axis and the third rotating axis is the second length, the distance between the third rotating axis and the fourth rotating axis is the third length, and the distance between the fourth rotating axis and the first rotating axis is the fourth length: The second length, the third length, and the fourth length are all greater than the first length, the first length, the second length, and the third length are all less than the fourth length, and the sum of the second length and the third length is less than the sum of the first length and the fourth length; and / or The first length is 28.4 mm, the second length is 51.9 mm, the third length is 56.9 mm, and the fourth length is 114.7 mm; When the prosthetic knee joint is in zero position, the angle between the center line of the first rotating shaft and the second rotating shaft and the horizontal line is 45.5°, and the angle between the center line of the third rotating shaft and the fourth rotating shaft and the horizontal line is -45.9°.

6. The prosthetic knee joint according to claim 4, characterized in that The prosthetic knee joint comprises two connecting arms, which are symmetrically arranged on both sides of the rotating member and the shell of the cylinder.

7. The prosthetic knee joint according to claim 1, wherein: The top of the rotating member is further provided with a quadrangular platform for connecting to the thigh end rod; and / or The bottom of the lower piston is also connected to the bottom cover of the cylinder body via a return spring.

8. The prosthetic knee joint according to claim 1, wherein: The position where the crank is connected to the rotating member is located behind the first rotating shaft and above the second rotating shaft.

9. The prosthetic knee joint according to claim 1, wherein: The cylinder body is a cylinder body with an open top and a closed bottom, and a partition is provided in the middle of the cylinder body. The upper air chamber is formed by the upper piston, the partition and the shell of the cylinder body. The piston rod vertically passes through the partition; the first throttle valve and the second throttle valve are provided to the partition.

10. The prosthetic knee joint according to claim 9, characterized in that The first throttle valve and the second throttle valve are embedded in the partition side by side along the radial direction of the cylinder body through clearance fit, and the ends of the valve bodies of the first throttle valve and the second throttle valve away from the first opening are both in contact with the pressing member located in the middle.

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