A servo-driven pneumatic prosthetic knee joint

Abstract

This invention provides a novel servo pneumatic prosthetic knee joint, relating to the field of prosthetic knee joints. It includes: a cylinder housing an upper air chamber and a lower air chamber, with an upper piston and a lower piston respectively mounted in the upper and lower air chambers; a first throttling valve and a second throttling valve, both comprising valve bodies; a first opening at the valve stem end near the valve core of the valve body; a second opening on the side wall of the valve body communicating with an inner cavity; a valve sleeve, movable left and right, fitting against the inner wall of the valve body; a through hole for the valve stem of the valve core to pass through, and a throttling channel communicating with the through hole and the inner cavity; and an adjusting spring fitted onto the valve stem; when the prosthetic knee joint is in the zero position, the throttling orifice at the connection between the throttling channel and the through hole is partially blocked by the valve stem portion of the valve core. The prosthetic knee joint provided by this invention has a simple structure and achieves adaptive damping adjustment of the prosthetic knee joint, enabling the prosthesis to follow the gait of the healthy side in real time.

Description

Technical Field

[0001] This invention relates to the field of prosthetic knee joints, and more particularly to a novel servo pneumatic prosthetic knee joint. Background Technology

[0002] Due to factors such as work-related injuries, traffic accidents, illnesses, natural disasters, and force majeure events, the demand for prostheses among amputees is gradually increasing. With the continuous improvement of my country's economic level and technological progress, amputees are placing increasingly higher demands on the performance of their prostheses.

[0003] Although pneumatic prosthetic knee joints are available in China, they cannot adaptively adjust the damping performance of the prosthetic knee joint, and the required swing speed of the prosthesis cannot automatically follow the swing speed requirements of the healthy side. This makes it very inconvenient for patients to use and cannot achieve the biomimetic characteristics of the human body's natural gait or the requirements for sports safety.

[0004] Existing technologies also include some prosthetic knee joint devices, such as the Chinese authorized invention with patent announcement number CN103271783B, entitled "A Prosthetic Knee Joint with Assistive Function," and the Chinese authorized invention with patent announcement number CN113244028B, entitled "A Throttle Valve Damping Wearable Robot Joint Drive Device." These devices often use motors or other power devices, and then use corresponding sensors and control devices to drive a throttle valve to change the flow rate. On the one hand, the structure is complex and the cost is high; on the other hand, the calculation and processing method of the control device has a certain lag, 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-mentioned technical problems. Summary of the Invention

[0006] This invention provides a novel servo pneumatic prosthetic knee joint with a simple structure that enables adaptive adjustment of the knee joint damping, allowing the prosthesis to follow the gait of the healthy side in real time.

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

[0008] The cylinder body has a relatively sealed upper air chamber and a lower air chamber inside. The upper air chamber and the lower air chamber are respectively equipped with an upper piston and a lower piston that can move up and down synchronously under the action of external force, connected by the same piston rod.

[0009] A first throttle valve and a second throttle valve are disposed in the housing of the cylinder block. Both the first throttle valve and the second throttle valve include a valve body containing an inner cavity. A valve core is disposed axially within the valve body. The valve body has a first opening at one end near the valve stem of the valve core. A second opening is disposed on the side wall of the valve body, communicating with the inner cavity. The inner cavity is provided with a valve sleeve that fits against the inner wall of the valve body and is movable left and right relative to the valve body. The valve sleeve includes a body, which has a through hole through which the valve stem of the valve core passes, and a throttle channel communicating with the through hole and the inner cavity. The valve stem of the valve core is also fitted with an adjusting spring whose two ends are respectively connected to the body and the valve body.

[0010] The first throttle valve is connected to the lower air chamber via a unidirectional air path through the upper air chamber, passing through the first opening and the second opening in sequence. The second throttle valve is connected to the upper air chamber via a unidirectional air path through the lower air chamber, passing through the second opening and the first opening in sequence.

[0011] When the prosthetic knee joint is in the zero position, the throttling orifice at the connection between the throttling channels of the first and second throttling valves and the through hole is blocked by the valve stem portion of the valve core. This technical feature allows the first and second throttling valves to reduce or increase the actual gas flow orifice when the prosthetic knee joint performs flexion and extension movements, respectively, thus achieving the necessary technical feature of adaptive damping increase and decrease.

[0012] According to the prosthetic knee joint of the present invention, when the prosthetic knee joint begins to flex from the zero position, the upper and lower pistons move downward under the action of an external force, for example, by relying on the rotation of the rotating component relative to the cylinder body, and by pressing down the crank to drive the upper and lower pistons to move downward. The space in the upper air chamber gradually decreases, and the gas flows into the lower air chamber through the air passages of the first throttle valve and the first one-way valve. During this process, the valve sleeve of the first throttle valve, except for the through hole and throttling channel that allow gas to pass through, forms a blockage for the gas. Therefore, the gas pushes the valve sleeve of the first throttle valve to move to the right relative to the valve body (valve stem), increasing the area of ​​the throttle orifice blocked by the valve stem at the connection between the throttle channel and the through hole. This means the actual throttle orifice through which gas passes becomes smaller, increasing flexion damping and decreasing the flexion angle. When the prosthetic knee joint transitions from flexion to extension, the upper and lower pistons move upwards under external force. At this time, the lower air chamber space gradually decreases, the upper air chamber is under negative pressure, and the gas in the lower air chamber passes through the second throttle valve and the second check valve. The air flows into the upper air chamber. During this process, the valve sleeve of the second throttle valve, except for the through hole and throttle channel through which gas can pass, obstructs the gas. Therefore, the gas pushes the valve sleeve of the second throttle valve to move to the left relative to the valve body (valve stem), making the area of ​​the throttle orifice at the connection between the throttle channel and the through hole blocked by the valve stem smaller. That is, the actual throttle orifice for gas to pass through becomes larger, and the extension damping decreases. According to the prosthetic knee joint of the present invention, an important innovation is the improvement of the structure of the first and second throttle valves. Based on the improvement of its own structure, the flow rate of the throttle valve 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, the cost is significantly reduced, and there is no lag problem caused by the calculation and processing by the control device. Based on this, the damping adaptive adjustment is achieved through the structure of rotating parts, cylinder, crank, first throttle valve and second throttle valve, which can dynamically and adaptively follow the healthy side gait in real time.

[0013] Optionally, the piston rod also has an axially extending inner bore, the top end of which communicates with the outside, and the bottom end of which communicates with the lower air chamber via a through hole.

[0014] According to this design, an axially extending inner hole is also provided through the piston rod, which makes the prosthetic knee joint move more smoothly during flexion and extension.

[0015] Secondly, the present invention also provides a lower limb prosthesis, including the prosthetic knee joint of the above-described technical solution.

[0016] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0017] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. The components in the drawings are not drawn to scale but are merely illustrative of the principles of the invention. For ease of illustration and description of certain parts of the invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the invention. In the drawings:

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

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

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

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

[0023] Figure 5 This 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 the state where the valve sleeve moves to the left relative to the valve body and abuts the pin.

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

[0025] Figure 7 This is a schematic diagram showing the relative positional distribution of the first, second, third, and fourth rotating axes in a prosthetic knee joint according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100. Prosthetic knee joint;

[0028] 110. Rotary parts;

[0029] 120. Cylinder block; 121. Piston rod; 122. Inner bore; 123. Upper piston; 124. Lower piston; 125. Return spring; 126. Divider section;

[0030] 131. Crank; 132. Connecting arm; 133. Connecting bracket;

[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. Throttling channel; 1473. Throttling port; 148. Adjusting spring; 149. Pin;

[0032] 151. First pivot; 152. Second pivot; 153. Third pivot; 154. Fourth pivot;

[0033] 160. A quadrangular frustum;

[0034] 170. Clamping parts. Detailed Implementation

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

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0037] The ordinal numbers such as "first" and "second" used in this invention are merely identifiers and do not have any other meaning, such as a specific order. Moreover, for example, the term "first component" does not imply the existence of "second component," and the term "second component" does not imply the existence of "first component."

[0038] It should be noted that the terms “up,” “down,” “front,” “back,” “left,” “right,” “inner,” “outer,” and similar expressions used in this article are for illustrative purposes only and are not intended to be limiting.

[0039] This invention provides a novel servo-pneumatic prosthetic knee joint 100. The prosthetic knee joint 100 can be applied, for example, in the field of rehabilitation aids, such as for prosthetic knee joints, and can solve the problem of existing prosthetic knee joints being unable to adaptively adjust the swing speed to match the healthy side's swing speed.

[0040] Existing technologies also include some prosthetic knee joint devices, such as the Chinese authorized invention with patent announcement number CN103271783B, entitled "A Prosthetic Knee Joint with Assistive Function," and the Chinese authorized invention with patent announcement number CN113244028B, entitled "A Throttle Valve Damping Wearable Robot Joint Drive Device." These devices often use motors or other power devices, and then use corresponding sensors and control devices to drive a throttle valve to change the flow rate. On the one hand, the structure is complex and the cost is high; on the other hand, the calculation and processing method of the control device has a certain lag, and the adaptability also needs to be improved.

[0041] To address the above problems, the present invention provides a novel servo-driven pneumatic prosthetic knee joint 100. In a preferred embodiment, such as... Figure 1 , Figure 3 and Figure 6 As shown, where Figure 1 This is a schematic diagram of the internal structure of a prosthetic knee joint according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a first throttle valve in a prosthetic knee joint according to an embodiment of the present invention, where the first throttle valve is in the state of the prosthetic knee joint at zero position; Figure 6 This is a schematic diagram of the internal structure of the 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 magnitude when the prosthetic knee joint 100 performs flexion and extension movements.

[0043] Specifically, the cylinder 120, located at the bottom, extends vertically. The cylinder 120 contains a relatively sealed upper and lower air chamber. The upper and lower air chambers are respectively equipped with an upper piston 123 and a lower piston 124, which are connected by the same piston rod 121 and can move synchronously up and down under external force. The two ends of the piston rod 121 can be threaded 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 120 via a return spring 125. The return spring 125 assists in the reset of the upper piston 123, the lower piston 124, and the piston rod 121. The upper and lower air chambers are not spatially fixed; their positions change with the movement of the upper piston 123 and the lower piston 124.

[0044] The ability of the upper piston 123 and the lower piston 124 to move synchronously up and down under the action of external force can be achieved through the rotary component 110 and the crank 131.

[0045] The top-mounted component is a rotating member 110 that is rotatable relative to the cylinder 120 in the front-rear direction. The rotating member 110 is rotatably connected to the upper piston 123 via a crank 131. The crank 131 is used to drive the piston rod 121 to move up and down. The rotating member 110 is a common structure in prosthetic knee joints 100, used to connect to the thigh end rod. It can adopt existing structures and will not be described in detail here.

[0046] To facilitate connection with the thigh end rod, a truncated pyramid 160 is also provided on the top of the rotating part 110. The truncated pyramid 160 can be installed, for example, by means of a threaded connection, to achieve quick assembly and disassembly.

[0047] The prosthetic knee joint 100 according to the present invention may further include a multi-bar linkage mechanism. The upper and lower ends of the multi-bar linkage mechanism are respectively rotatably connected to the housing of the rotating member 110 and the cylinder 120, so as to realize the rotation of the rotating member 110 relative to the cylinder 120 in the front-rear direction. The specific form of the multi-bar linkage mechanism is not limited. For example, the multi-bar mechanism may include a connecting arm 132 and a connecting frame 133.

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

[0049] The upper end of the connecting bracket 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 bracket 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 bracket 133 can be an H-type connecting bracket 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 component 110, the connecting arm 132, the cylinder 120, and the connecting frame 133 forms the four-bar linkage of the prosthetic knee joint 100.

[0051] The top end of the crank 131 is rotatably connected to the rotating component 110, and the bottom end of the crank 131 is rotatably connected to the upper piston 123, so that when the rotating component 110 flips in the front-back direction, it drives the upper piston 123 and the lower piston 124 to move up and down synchronously.

[0052] A first throttle valve 141 and a second throttle valve 142 are disposed in the housing of the cylinder block 120. Both the first throttle valve 141 and the second throttle valve 142 include a valve body 143 containing an inner cavity. A valve core 144 is axially disposed within the valve body 143. The valve body 143 has a first opening 145 at one end near the valve stem 1441 of the valve core 144. A second opening 146 communicating with the inner cavity is provided on the side wall of the valve body 143. A valve sleeve 147, for example, a copper valve sleeve 147, is disposed within the inner cavity and is fitted to the inner wall of the valve body 143, and is movable left and right relative to the valve body 143. The valve sleeve 147 may include a cylindrical body. The body has a through hole 1471 through which the valve stem 1441 of the valve core 144 passes, and a throttle channel 1472 communicating between the through hole 1471 and the inner cavity. Among them, the valve stem 1441 of the valve core 144 is also fitted with an adjusting spring 148 whose two ends are respectively connected to the body and the valve body 143.

[0053] In this design, the first opening 145 of the first throttle valve 141 connects to the upper air chamber. The second opening 146 of the first throttle valve 141 connects to the lower air chamber via a first check valve. The first check valve is activated 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 connects to the upper air chamber via a reverse second check valve. The second opening 146 of the second throttle valve 142 connects to the lower air chamber. The second check valve is activated 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 in the zero position, the throttling orifice 1473 at the connection between the throttling channel 1472 of the first throttling valve 141 and the through hole 1471 is partially blocked by the valve stem 1441 of the valve core 144. This is understandable, due to considerations of drawing repetition. Figure 3 The diagram shows the state of the first throttle valve 141 at this time, 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 120 and drives the upper piston 123 and lower piston 124 to move downward by pressing down the crank 131. The space of the upper air chamber gradually becomes smaller, and the gas flows to the lower air chamber through the air passage of the first throttle valve 141 and 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, the valve sleeve 147 of the first throttling valve 141 (left end face) blocks the gas. As a result, the gas pushes the valve sleeve 147 of the first throttling valve 141 to move to the right relative to the valve body 143 (valve stem 1441), which makes the area of ​​the throttling orifice 1473 at the connection between the throttling channel 1472 and the through hole 1471 blocked by the valve stem 1441 larger. That is, the actual throttling orifice 1473 that allows the gas to pass through becomes smaller, the buckling damping increases, and the buckling angle becomes smaller. Of course, when the valve sleeve 147 of the first throttle valve 141 moves to its limit position relative to the valve body 143, the throttle port 1473 at the connection between the throttle channel 1472 and the through hole 1471 remains connected due to the obstruction of the adjusting spring 148, ensuring that gas can flow, but it is smaller than the throttle port 1473 when the prosthetic knee joint 100 is in the zero position. Thus, the first throttle valve 141 undertakes adaptive adjustment of flexion damping. After the prosthetic knee joint 100 completes its flexion action, the valve sleeve 147 of the first throttle valve 141 can be reset.

[0057] Then, refer to Figure 5When the prosthetic knee joint 100 transitions from flexion to extension, the upper piston 123 and lower piston 124 move upward under the action of the return spring 125 and the upward pull of the crank 131. At this time, the space in the lower air chamber gradually decreases, the upper air chamber is under negative pressure, and the gas in the lower air chamber flows to the upper air chamber through the air passage of the second throttle valve 142 and 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, besides allowing gas to pass through the through hole 1471 and the throttle channel 1472, obstructs the gas flow. Consequently, 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), reducing the area of ​​the throttle orifice 1473 at the connection between the throttle channel 1472 and the through hole 1471 blocked by the valve stem 1441. This results in a larger throttle orifice 1473 actually allowing gas to pass through, thus reducing the extension damping. Therefore, the second throttle valve 142 performs adaptive adjustment of the extension damping. After the prosthetic knee joint 100 completes its extension movement, the valve sleeve 147 of the second throttle valve 142 can return to its original position.

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

[0059] To facilitate the more efficient installation of the first throttle valve 141 and the second throttle valve 142, the cylinder block 120 also includes a partition 126 in its central portion. The first throttle valve 141 and the second throttle valve 142 can be fitted side-by-side into the partition 126 along the radial direction of the cylinder block 120 via a clearance fit. (Reference) Figure 2 The ends of the valve bodies 143 of the first throttle valve 141 and the second throttle valve 142 that are away from the first opening 145 abut against the clamping member 170 located in the middle. That is, the throttle valves are fixed by the clamping member 170 pressing down on the ends of the valve bodies 143 of the first throttle valve 141 and the second throttle valve 142 that are away from the first opening 145. The clamping member 170 is not limited to a specific type, and can be, for example, a screw.

[0060] Furthermore, the cylinder body 120 can be an open-top, closed-bottom cylinder body 120. The upper air chamber can be formed 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 it can be a separate structure. The piston rod 121 vertically passes through the partition 126.

[0061] refer to Figure 6In the illustrated embodiment, the piston rod 121 also has an axially extending inner bore 122. The top end of the inner bore 122 communicates with the outside atmosphere. The bottom end of the inner bore 122 communicates with the lower air chamber via a through hole. By providing an axially extending inner bore 122 in the piston rod 121, the prosthetic knee joint 100 performs flexion and extension movements more smoothly.

[0062] refer to Figure 5 The valve body 143 of the first throttle valve 141 and the second throttle valve 142 is also provided with a radially extending limiting 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 fitted 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 shaft 151 and the second rotating shaft 152 is the first length L1. The distance between the second rotating shaft 152 and the third rotating shaft 153 is the second length L2. The distance between the third rotating shaft 153 and the fourth rotating shaft 154 is the third length L3. The distance between the fourth rotating shaft 154 and the first rotating shaft 151 is the 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 could be 28.4 mm. The second length could be 51.9 mm. The third length could be 56.9 mm. The fourth length could be 114.7 mm.

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

[0066] Through the above design, the instantaneous center curve of the four-bar linkage (i.e., the combination mechanism of rotating component 110, connecting arm 132, cylinder 120 and connecting frame 133) in the prosthetic knee joint 100 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 crank 131 can be connected to the rotary member 110 at a position behind the first shaft 151 and above the second shaft 152.

[0068] Secondly, the present invention also provides a lower limb prosthesis (not shown) comprising the prosthetic knee joint 100 of the above embodiments. 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 invention will be readily conceived and understood by those skilled in the art in conjunction with the description and practice of the invention disclosed herein. The descriptions and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are defined by the claims.

Claims

1. A servo-driven pneumatic prosthetic knee joint, characterized in that, The prosthetic knee joint includes: The cylinder has a relatively sealed upper and lower air chamber. The upper and lower air chambers are respectively equipped with an upper piston and a lower piston that can move up and down synchronously under the action of external force, connected by the same piston rod. The first throttle valve and the second throttle valve are disposed in the housing of the cylinder block. Both the first throttle valve and the second throttle valve include a valve body with a valve core disposed axially in the inner cavity. The valve body has a first opening at the valve stem end near the valve core. The side wall of the valve body is provided with a second opening communicating with the inner cavity. The inner cavity is provided with a valve sleeve that fits against the inner wall of the valve body and can move left and right relative to the valve body. The body of the valve sleeve is provided with a through hole for the valve stem of the valve core to pass through and a throttle channel communicating with the through hole and the inner cavity. The valve stem of the valve core is sleeved with an adjusting spring at both ends connected to the body and the valve body respectively. The first opening of the first throttle valve is connected to the upper air chamber, and the second opening of the first throttle valve is connected to the lower air chamber via the first check valve. The first throttle valve is connected to the lower air chamber by a one-way air path that passes through the upper air chamber sequentially through the first opening, the second opening, and the first check valve. The first opening of the second throttle valve is connected to the upper air chamber via the reverse second check valve, and the second opening of the second throttle valve is connected to the lower air chamber. The second throttle valve is connected to the upper air chamber by a one-way air path that passes through the lower air chamber sequentially through the second opening, the first opening, and the second check valve. When the prosthetic knee joint is in the zero position, the throttling orifice at the connection between the throttling channel of the first throttling valve and the through hole of the second throttling valve is blocked by the valve stem portion of the corresponding valve core.

2. The prosthetic knee joint according to claim 1, characterized in that, The piston rod also has an axially extending inner bore, the top of which communicates with the outside, and the bottom of which communicates with the lower air chamber via a through hole.

3. The prosthetic knee joint according to claim 1, characterized in that, The valve bodies of the first and second throttle valves are further provided with radially extending limiting pins at the first opening, so that when the valve sleeve abuts against the pin to the left, it is still fitted onto the valve stem of the corresponding valve core; and / or The prosthetic knee joint also includes a rotating component configured to be rotatable relative to the cylinder in the front-rear direction, the rotating component being rotatably connected to the upper piston via a crank.

4. The prosthetic knee joint according to claim 3, characterized in that, The prosthetic knee joint further includes a multi-bar linkage mechanism for realizing the rotation of the rotating component relative to the cylinder in the front-rear direction, the multi-bar linkage mechanism including: A connecting arm, the upper end of which is rotatably connected to the front side of the rotating part via a first rotating shaft, and the lower end of which is rotatably connected to the upper front side of the housing of the cylinder via a fourth rotating shaft; A connecting bracket, the upper end of which is rotatably connected to the rear side of the rotating part via a second rotating shaft, and the lower end of which is rotatably connected to the upper rear side of the cylinder housing via a third rotating shaft; The first, second, third, and fourth rotating shafts are arranged in parallel.

5. The prosthetic knee joint according to claim 4, characterized in that, The distance between the first and second rotating shafts is a first length, the distance between the second and third rotating shafts is a second length, the distance between the third and fourth rotating shafts is a third length, and the distance between the fourth and first rotating shafts is a fourth length. Wherein, 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; When the prosthetic knee joint is in the zero position, the angle between the line connecting the centers of the first and second rotating axes and the horizontal line is 45.5°, and the angle between the line connecting the centers of the third and fourth rotating axes and the horizontal line is -45.9°.

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

7. The prosthetic knee joint according to claim 3, characterized in that, The top of the rotating component is also provided with a truncated pyramid for connection to the thigh end rod; and / or The bottom of the lower piston is also connected to the bottom cover of the cylinder via a return spring.

8. The prosthetic knee joint according to claim 4, characterized in that, The crank is connected to the rotating component at a position behind the first shaft and above the second shaft.

9. The prosthetic knee joint according to claim 1, characterized in that, The cylinder body is an open-top, closed-bottom cylinder body, and the middle part of the cylinder body also has a partition. The upper air chamber is formed by the upper piston, the partition and the shell of the cylinder body. The piston rod extends vertically through the partition; the first throttle valve and the second throttle valve are disposed in 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 side by side in the partition along the radial direction of the cylinder body through clearance fit, and the valve bodies of the first throttle valve and the second throttle valve at the ends away from the first opening abut against the clamping member located in the middle.

Images