Prosthetic knee joint

Abstract

This utility model relates to a prosthetic knee joint, including a joint body and a damping support rod mechanism. The damping support rod mechanism is telescopic and has a damping effect during telescopic movement. The joint body is used to connect with a thigh receiving cavity. It also includes a connecting rod bracket. The connecting rod bracket is rotatably connected to the joint body through a pivot structure A. The lower end of the connecting rod bracket is used to connect to the prosthetic lower leg. The upper end of the damping support rod mechanism is rotatably connected to the joint body through a pivot structure B, and the lower end is rotatably connected to the connecting rod bracket through a pivot structure C. When the prosthetic knee joint is installed on the human body and is in a standing position, the pivot structure B is located in front of and below the pivot structure A.

Description

Technical Field

[0001] This utility model relates to the field of medical rehabilitation equipment technology, specifically to a prosthetic knee joint. Background Technology

[0002] To enable amputees to live, study, and work like normal people, artificial prostheses are needed. Thigh prostheses mainly consist of a stump socket, knee joint, tibial canal, ankle joint, prosthetic foot plate, and various connectors, among which the prosthetic knee joint is the most important component.

[0003] Existing prosthetic knee joints can be categorized by material, including stainless steel, titanium alloy, aluminum alloy, and carbon fiber; by structure, they are divided into single-axis and multi-axis types; and by damping function, they are classified as mechanical, pneumatic, hydraulic, and electrically controlled. Among these, the most popular and commonly used are the linkage-type pneumatic and hydraulic aluminum alloy prosthetic knee joints. This series of prosthetic knee joints is simple in structure, lightweight, easy to manufacture, and inexpensive, making it popular with patients. This series of prosthetic knee joints generally consists of upper and lower connecting parts, a linkage mechanism, and a pneumatic or hydraulic damping cylinder. The upper joint body connects to the prosthetic socket, and the lower joint body connects to the prosthetic tibial tube. The linkage mechanism completes the flexion and extension movements of the thigh prosthesis, thus enabling walking. The damping cylinder is a functional component located between the upper and lower joint bodies. Its piston head has a damping extension function, used to adjust the speed of joint movement, controlling the patient's walking speed and gait quality when using the thigh prosthetic knee joint. Different damping cylinders provide different functions for the prosthetic knee joint and are one of the core components of the prosthetic knee joint.

[0004] Currently, most prosthetic knee joints use multi-link mechanisms to form complex motion structures. The driving force of the piston head in the damping cylinder comes from the force transmitted from the residual limb's swing to the piston head's axial direction. Due to the limited volume of the prosthetic knee joint, it is difficult to ensure that the piston head's motion load direction during walking is entirely axial when designing the damping support mechanism. This can lead to radial forces that are useless or harmful to the piston head's reciprocating motion during movement. In existing designs, the rotational connection point at the upper end of the damping support rod mechanism is generally located behind the joint spindle of the upper joint body. When the knee joint initially bends, the damping support rod mechanism is subjected to pressure and generates a large radial component force. Due to the radial force, the piston head and sliding bearings will wear and deform, leading to air and oil leaks, operational wobbling, and shortening the service life of the prosthetic knee joint. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the technical problem to be solved by this utility model is to provide a prosthetic knee joint with a simple structure that can effectively reduce the radial force on the damping support mechanism during operation and improve its service life.

[0006] To achieve the above objectives, this utility model provides a prosthetic knee joint, including a joint body and a damping support rod mechanism. The damping support rod mechanism is telescopic and has a damping effect during telescopic movement. The joint body is used to connect with a thigh receiving cavity. It also includes a connecting rod bracket. The connecting rod bracket is rotatably connected to the joint body through a pivot structure A. The lower end of the connecting rod bracket is used to connect to the prosthetic lower leg. The upper end of the damping support rod mechanism is rotatably connected to the joint body through a pivot structure B, and the lower end is rotatably connected to the connecting rod bracket through a pivot structure C. When the prosthetic knee joint is installed on the human body and is in a standing position, the pivot structure B is located in front of and below the pivot structure A.

[0007] Furthermore, the joint body is provided with a connecting cavity for connecting with the thigh receiving cavity, and a threaded through hole located on the side wall of the connecting cavity.

[0008] Furthermore, the lower end of the connecting rod bracket is provided with a lower leg connecting clamp for connecting with the prosthetic lower leg.

[0009] Furthermore, the damping support rod mechanism includes a damping cylinder, which includes a cylinder body assembly, a piston rod, and a piston head fixed to the piston rod. The cylinder body assembly of the damping cylinder is rotatably connected to the connecting rod support via a rotating shaft structure C, and the piston rod is rotatably connected to the joint body via a rotating shaft structure B. Alternatively, the piston rod of the damping cylinder is rotatably connected to the connecting rod support via a rotating shaft structure C, and the cylinder body assembly is rotatably connected to the joint body via a rotating shaft structure B.

[0010] Furthermore, the cylinder assembly of the damping cylinder includes a first cylinder section, a second cylinder section, and a damping control body. The damping control body connects the first cylinder section and the second cylinder section and is used to regulate the flow of fluid medium between the inner cavities of the first cylinder section and the second cylinder section. The piston head is located in the second cylinder section. The first end of the piston rod passes through the damping control body and the first cylinder section and extends out of the first cylinder section. The piston rod is also provided with a fluid channel, which connects the space in the second cylinder section located on the side of the piston head tail end with the inner cavity of the first cylinder section.

[0011] Furthermore, the damping control body has a throttling orifice connecting the inner cavity of the first cylinder and the inner cavity of the second cylinder, and the damping control body is provided with a standing locking mechanism that can close or open the throttling orifice.

[0012] Furthermore, the damping control body has a throttling orifice connecting the inner cavity of the first cylinder and the inner cavity of the second cylinder, and the damping control body is provided with a control valve that can control the opening and closing size of the throttling orifice.

[0013] Furthermore, the fluid channel in the piston rod extends axially and penetrates the tail end face of the piston rod located in the second cylinder section. The damping cylinder also includes a non-stretching damper located at the tail end of the second cylinder section. The first end of the non-stretching damper is provided with a tapered portion that cooperates with the fluid channel. An oil inlet channel is provided inside the non-stretching damper that extends axially to its first end face. An oil inlet port connecting the oil inlet channel (282) and the inner cavity of the second cylinder section is provided on one side of the tail end of the tapered portion. When the piston rod retracts into the cylinder assembly, the fluid channel (221) can be fitted onto the tapered portion and the two abut against each other.

[0014] Furthermore, the damping cylinder also includes an adjusting bolt, which is screwed onto the second cylinder portion, and the non-extension damper is fixed to the adjusting bolt.

[0015] Furthermore, an extension end buffer is fitted onto the section of the piston rod that extends out of the cylinder assembly, and a limiting surface is provided on the piston rod that abuts against the head end of the extension end buffer.

[0016] As described above, the prosthetic knee joint of this utility model has the following beneficial effects:

[0017] The triangular linkage motion mechanism is simple in structure. By setting the pivot structure B between the damping support rod mechanism and the joint body in front of and below the pivot structure A between the linkage bracket and the joint body, the damping support rod mechanism rotates and is stretched by tension during the leg-lifting walking process. Compared with the existing conventional design, the radial force on the damping support rod mechanism is small, which can solve the problem of damage caused by excessive radial separation during the movement of the damping support rod mechanism. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the prosthetic knee joint of this utility model.

[0019] Figure 2 This is a rear view of the prosthetic knee joint of this utility model.

[0020] Figure 3 This is a right-side view of the prosthetic knee joint of this utility model.

[0021] Figure 4 This is a schematic diagram of the damping cylinder in this utility model.

[0022] Figure 5 This is a schematic diagram of the damping cylinder in this utility model.

[0023] Figure 6 This is a side view of the damping cylinder in this utility model.

[0024] Figure 7 for Figure 6 EE section view.

[0025] Figure 8 for Figure 7 The enlarged view of the X circle in the image.

[0026] Figure 9 for Figure 7 A magnified view of the Y-circle in the image.

[0027] Figure 10 This is a schematic diagram of the non-stretch damper in this utility model.

[0028] Figure 11 This is a simplified schematic diagram of the movement of the prosthetic knee joint in this utility model.

[0029] Figure 12 This is a simplified schematic diagram of the prosthetic knee joint of this utility model in a standing position.

[0030] Figure 13 This is a simplified schematic diagram of the prosthetic knee joint of this utility model during the normal walking and leg lifting process.

[0031] Figure 14 This is a simplified schematic diagram of the prosthetic knee joint of this utility model during high leg raises or deep squats.

[0032] Explanation of icon numbers

[0033] 1. Joint body

[0034] 11 Connecting cavity

[0035] 12 Threaded Through Holes

[0036] 2 Damping support rod mechanism

[0037] 21 Cylinder Block Assembly

[0038] 211 First Cylinder Section

[0039] 212 Second Cylinder Section

[0040] 213 Damping Control System

[0041] 22 Piston Head

[0042] 221 Fluid Channel

[0043] 222 Connection end

[0044] 23 Piston body

[0045] 24 Control valve

[0046] 25 Gravity Lock Mechanism

[0047] 26 Standing Locking Mechanism

[0048] 27 Extended end buffer

[0049] 28. No extension damper

[0050] 281 Conical section

[0051] 282 Oil Inlet Flow Channel

[0052] 283 Oil Inlet

[0053] 29 Adjusting bolts

[0054] 3-linkage bracket

[0055] 31 Lower leg connecting clamps

[0056] 32 Gravity Link

[0057] 4. Shaft Structure A

[0058] 5. Shaft Structure B

[0059] 6. Shaft Structure C

[0060] 7 Piston head bearing Detailed Implementation

[0061] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0062] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0063] See Figures 1 to 14This invention provides a prosthetic knee joint, including a joint body 1 and a damping support rod mechanism 2. The damping support rod mechanism 2 is freely extendable and retractable, and provides a damping effect during extension and retraction. The joint body 1 is used to connect with a thigh receiving cavity. It also includes a connecting rod bracket 3, which is rotatably connected to the joint body 1 via a pivot structure A4. The lower end of the connecting rod bracket 3 is used to connect to the prosthetic lower leg. The upper end of the damping support rod mechanism 2 is rotatably connected to the joint body 1 via a pivot structure B5, and the lower end is rotatably connected to the connecting rod bracket 3 via a pivot structure C6. When the prosthetic knee joint is installed on the human body and in a standing position, the pivot structure B5 is located in front of and below the pivot structure A4. The damping support rod mechanism 2 can employ existing mechanisms, such as hydraulic damping cylinders, pneumatic-hydraulic damping cylinders, or other damping cylinders with damping extension and retraction functions, or it can use a support rod with elastic damping effect, allowing the damping support rod mechanism 2 to freely extend and retract while providing a damping effect during extension and retraction.

[0064] The main working principle of this prosthetic knee joint is as follows: the joint body 1, the damping support rod mechanism 2, and the connecting rod bracket 3 form a triangular frame structure with one side extendable, resulting in a simple structure and movement. In use, the lower end of the connecting rod bracket 3 connects to the prosthetic lower leg, and the joint body 1 connects to the residual thigh limb via the thigh receiving cavity. After installation, the front side of the prosthetic knee joint faces forward. For simplified movement instructions, see [link to manual description]. Figure 11 Simplifying the pivot structures A4, B5, and C6 to points A, B, and C respectively, the linkage support 3 can be simplified to a non-extendable rod AC, the joint body 1 to a non-extendable rod AB, and the damping support rod mechanism 2 to a extendable rod BC. During prosthetic knee joint movement, the following states exist: (a) When in a standing position, joint body 1 is immobile and applies downward pressure through points A and C. See [reference needed] Figure 12 At this point, rod AC is preferably in a vertical or nearly vertical position, and point B is located in front of and below point A. The supporting force is mainly borne by rod AC. The vertical pressure F transmitted to point B through joint 1 is relatively small. F1 and F2 are the supporting force along the axial direction of rod BC and the radial component force, respectively. F2 = F*sin(∠ABC-90°). The magnitude of the radial force F2 is affected by ∠ABC. At this point, ∠ABC can be designed to be relatively close to 90°, so the radial component force F1 will be very small. (b) When a person walks forward normally, see Figure 13 The thigh is raised forward, causing joint 1 to swing upward, that is, the rod AB rotates forward and upward around point A (i.e., Figure 12 and 13(Rotating clockwise in the diagram), the prosthetic leg leaves the ground. Point C experiences a downward pull due to the weight and inertia of the leg. Rod AC is in or nearly vertical. Point B experiences a force F' from the rotation of rod AB, resulting in a component force F1 along the axis of rod BC. ’ This will gradually lengthen rod BC, while ∠ABC will gradually decrease, and the radial component force F2 ’ =F'*sin(∠ABC-90°), will also gradually decrease first. During normal walking, the leg lift angle is generally small, for example, around 30°. After the leg lift is completed, the bar AB rotates through a certain angle, at which point B can move to a certain height above point A. See [reference needed]. Figure 13 Point B can also be at the same height as point A or slightly lower than point A, and ∠ABC is also located around 90°, meaning the absolute value of ∠ABC-90° is relatively small. Therefore, the radial component force F2 generated throughout the process is relatively small. ’ Both are very small. Therefore, during normal walking and leg lifting, the radial component F2 of the rod BC... ’ All are within a relatively small range. (c) When a person is in a squatting or high-knee position, that is, when the rod AB continues to rotate around point A at a large angle, preferably, point B moves above point A, and at this time, points A, B and C are collinear. At this time, the rod BC can only bear axial pressure under the weight of the person and is not subjected to radial force.

[0065] The prosthetic knee joint of this invention adopts a triangular linkage motion mechanism, which has a simple structure. By placing the rotating shaft structure B5 in front and below the rotating shaft structure A4, the damping support rod mechanism 2 can rotate and be stretched by tension during the leg lifting and walking process, i.e., during knee flexion. The radial force is small. Compared with the existing conventional design, it can solve the problem of damage caused by excessive radial force during the movement of the damping support rod mechanism 2. Specifically, for hydraulic or pneumatic damping cylinders, radial force will cause radial wear of the sliding bearing that plays a supporting and guiding role. For elastic support rods with elastic damping effect, excessive radial force will cause radial deformation or fatigue damage to the elastic support rod.

[0066] See Figures 1 to 14 The present invention will be further described below with reference to a specific embodiment:

[0067] See Figure 1 and Figure 2In this embodiment, as a preferred design, the joint body 1 is provided with a connecting recess 11 for connecting to the thigh receiving cavity, and a threaded through hole 12 located on the side wall of the connecting recess 11. During installation, the lower end of the thigh receiving cavity is inserted into the connecting recess 11, and then a connecting bolt is screwed into the threaded through hole 12 and screwed into the thigh receiving cavity, realizing flexible assembly and disassembly of the thigh receiving cavity and the joint body 1, which is convenient to use. The connecting recess 11 of the joint body 1 can be in the form of a concave square pyramid, and the connecting part of the thigh receiving cavity and the connecting recess 11 of the joint body 1 are connected by a matching convex square pyramid and a concave square pyramid. Of course, the connecting recess 11 can also be other shapes.

[0068] See Figure 1 and Figure 2 In this embodiment, as a preferred design, the lower end of the connecting rod bracket 3 is provided with a lower leg connecting clamp 31 for connecting with the prosthetic lower leg. During installation, the leg tube of the prosthetic lower leg is inserted into the lower leg connecting clamp 31, and then the lower leg connecting clamp 31 is clamped and fixed on the prosthetic lower leg using bolts or other existing methods, which can achieve flexible and stable installation, and at the same time facilitate disassembly and replacement.

[0069] See Figure 1 and Figure 2 In this embodiment, as a preferred design, the damping support rod mechanism 2 adopts a damping cylinder. The fluid medium in this damping cylinder that provides damping and buffering is hydraulic oil, i.e., a hydraulic damping cylinder. The damping cylinder includes a cylinder assembly 21, a piston head 23, and a piston rod 22 fixed to the piston head 23. The piston head 23 preferably uses a sealing ring made of highly wear-resistant polyurethane material. The tail end of the cylinder assembly 21 is rotatably connected to the connecting rod support 3 via a rotating shaft structure C6, and the piston rod 22 faces upward and is rotatably connected to the joint body 1 via a rotating shaft structure B5. Alternatively, the damping cylinder can be reversed, with the piston rod 22 facing downward and rotatably connected to the connecting rod support 3 via the rotating shaft structure C6, while the cylinder assembly 21 is rotatably connected to the joint body 1 via the rotating shaft structure B5. When the piston rod 22 and piston head 23 of the damping cylinder move within the cylinder assembly 21, the damping effect is achieved through the internal hydraulic oil. The damping cylinder can adopt various suitable existing design structures, and the fluid medium in the damping cylinder can also be gas, that is, the damping cylinder is pneumatic.

[0070] In this embodiment, see Figure 4 , Figure 5 and Figure 7As a preferred design, the cylinder assembly 21 of the damping cylinder includes a first cylinder section 211, a second cylinder section 212, and a damping control body 213. The damping control body 213 connects the first cylinder section 211 and the second cylinder section 212 and is used to regulate the flow exchange of fluid medium in the inner cavity of the first cylinder section 211 and the inner cavity of the second cylinder section 212. Specifically, a throttling orifice connecting the inner cavity of the first cylinder section 211 and the inner cavity of the second cylinder section 212 can be provided in the damping control body 213. The piston head 23 is located in the second cylinder section 212. The first end of the piston rod 22 passes through the damping control body 213 and the first cylinder section 211 and extends out from the extension port of the first cylinder section 211. The piston rod 22 is also provided with a fluid channel 221, which connects the space in the second cylinder section 212 located on the side of the piston head 23 (i.e., the lower side in this embodiment) with the inner cavity of the first cylinder section 211. When the piston rod 22 retracts within the cylinder assembly 21, hydraulic oil in the second cylinder section 212, located below the piston head 23, enters the first cylinder section 211 through the fluid passage 221 in the piston rod 22, and flows into the second cylinder section 212 through the throttle orifice in the damping control body 213. When the piston rod 22 extends within the cylinder assembly 21, hydraulic oil in the second cylinder section 212, located above the piston head 23, flows into the first cylinder section 211 through the throttle orifice in the damping control body 213, and enters the space below the piston head 23 in the second cylinder section 212 through the fluid passage 221 in the piston rod 22. In this way, the extension and retraction of the piston rod 22 is damped.

[0071] In this embodiment, see Figure 4 , Figure 5 and Figure 7 Furthermore, the damping control body 213 is equipped with a standing locking mechanism 26 that can close or open the throttle orifice. When the prosthetic knee joint is in a standing position, the damping cylinder needs to remain stable and no longer perform extension and retraction movements. The standing locking mechanism 26 closes the throttle orifice, preventing relative flow of hydraulic oil between the inner chambers of the first cylinder 211 and the second cylinder 212, thus stabilizing the position of the piston head 23 and piston rod 22 and maintaining a stable standing position. When walking is required, the standing locking mechanism 26 opens the throttle orifice, and the damping control body 213 operates normally. The standing locking mechanism 26 can employ various existing suitable structures, such as a regulating valve located in the throttle orifice and a handle that drives the regulating valve, which in turn drives the regulating valve to cut off or open the throttle orifice.

[0072] In this embodiment, see Figure 4 , Figure 5 and Figure 7Furthermore, the damping control body 213 is equipped with a control valve 24 that can control the opening and closing size of the throttle orifice. There can be two throttle orifices, and two control valves 24, each controlling one orifice. By adjusting the opening and closing size of the throttle orifice through the control valves 24, the flow rate of the hydraulic oil during the exchange between the inner chambers of the first cylinder 211 and the second cylinder 212 can be adjusted, thereby adjusting the damping received by the piston rod 22 and piston head 23 during movement, that is, adjusting the operating speed of the piston rod 22 during extension and retraction. Furthermore, the damping control body 213 is provided with a gravity locking mechanism 25, and the connecting rod bracket 3 is fixed with a gravity connecting rod 32 connected to the gravity locking mechanism 25. The gravity locking mechanism 25 can control the opening and closing of the throttle orifice. When the joint body 1 rotates upward with the thigh, the gravity connecting rod 32 pulls the gravity locking mechanism 25, so that the opening of the throttle orifice gradually decreases and the damping effect gradually increases. When the joint body 1 rotates downward with the thigh, the opposite is true, so that the opening of the throttle orifice gradually increases and the damping effect decreases.

[0073] In this embodiment, see Figure 4 , Figure 5 and Figure 7As a preferred design, the fluid channel 221 in the piston rod 22 extends axially and penetrates the tail end face of the piston rod 22 located in the second cylinder section 212. The damping cylinder also includes a non-stretching damper 28 located at the tail end of the second cylinder section 212. The first end of the non-stretching damper 28 is provided with a tapered portion 281 that cooperates with the fluid channel 221. The tapered portion 281 and the fluid channel 221 are preferably coaxial. An oil inlet channel 282 is provided inside the non-stretching damper 28, which extends axially to its first end face. An oil inlet port 283 is provided on one side of the tail end of the tapered portion 281, which connects the oil inlet channel 282 and the inner cavity of the second cylinder section 212. When the piston rod 22 retracts into the cylinder assembly 21, the fluid channel 221 can be fitted onto the tapered portion 281 and the two abut against each other. With the above configuration, as the prosthetic knee joint moves from a raised position to a standing position, the piston rod 22 retracts inward, and the port of the fluid channel 221 on its tail end gradually approaches and aligns with the conical portion 281. This reduces the amount of hydraulic oil in the second cylinder 212 located below the piston head 23 that directly enters the fluid channel 221. Instead, the oil needs to enter the fluid channel 221 through the oil inlet 283 and oil inlet channel 282 of the non-extension damper 28. In other words, the non-extension damper 28 is similar to a conical valve with an oil hole, thereby adjusting the damping of the prosthetic knee joint to increase when approaching the standing position, so as to play a buffering role, reduce rigid vibration, and make the use more stable and reliable. Furthermore, the damping cylinder also includes an adjusting bolt 29, which is screwed to the tail end of the second cylinder section 212. The non-extending damper 28 is fixed on the adjusting bolt 29. By adjusting the length of the adjusting bolt 29 extending into the second cylinder section 212, the axial position of the non-extending damper 28 within the second cylinder section 212 can be adjusted. This allows for adjustment of the position where the piston rod 22 begins to interact with the non-extending damper 28 during the retraction movement and the retraction stop position, making it more flexible and convenient to use.

[0074] In this embodiment, see Figure 4 , Figure 5 and Figure 7 As a preferred design, the piston rod 22 extends out of the cylinder assembly 21 and is fitted with an extension end buffer 27. A limiting surface is provided on the piston rod 22 that abuts against the front end of the extension end buffer 27. That is, the extension end buffer 27 is located between the front end of the first cylinder section 211 and the limiting surface. A connecting end 222 is fixedly provided at the front end (i.e., the upper end) of the piston rod 22. Specifically, the connecting end 222 can be a coupling. The connecting end 222 is rotatably connected to the joint body 1 via a rotating shaft structure B5. The tail end face of the connecting end 222 forms a limiting surface that abuts against the extension end buffer 27. When the piston rod 22 retracts, it can abut against and stop with the front end face of the first cylinder section 211 of the cylinder assembly 21 through the extension end buffer 27, further providing a buffering effect to reduce rigid vibration and make the operation more stable and reliable.

[0075] In this embodiment, sliding bearings for radially limiting the piston rod 22 are also provided at both ends of the cylinder assembly 21. The two sliding bearings are respectively installed in conjunction with the cylinder assembly 21 via upper and lower plugs. Internal seals are installed on the side of each sliding bearing facing the interior of the cylinder assembly 21. An external seal is also installed at the protruding end of the piston rod 22. The external seal includes an annular seal and an annular clamp for axially limiting the annular seal. The annular seal includes a sealing lip and a connecting portion that mates with the annular clamp. The thickness of the sealing lip is greater than the thickness of the connecting portion. Other suitable existing structures can also be used for radial limiting and sealing between the piston rod 22 and the cylinder assembly 21.

[0076] In this invention, the damping cylinder is not limited to the form described above. In other embodiments, other suitable existing designs can also be used. Specifically, the damping adjustment body 213 and its adjustment method can adopt other suitable existing designs. In addition, the damping cylinder as a whole can also adopt other suitable existing designs. At the same time, the damping support rod mechanism 2 is not limited to using a damping cylinder; other support rods with damping telescopic functions can also be used.

[0077] See Figure 1 In this embodiment, as a preferred design, the pivot structure A4 between the connecting rod support 3 and the joint body 1 is a bearing. Its inner and outer rings are fixed to the joint body 1 and the connecting rod support 3, respectively, enabling smooth rotation between the connecting rod support 3 and the joint body 1. This bearing, as the main shaft of the prosthetic knee joint, needs to withstand significant forces; therefore, a large-diameter bearing with an outer diameter of 20mm to 30mm is preferred. See also... Figure 4 The rotating shaft structure B5 is a cylindrical shaft, installed in a piston head bearing 7, which is embedded in the front end of the piston rod 22 of the damping cylinder, enabling smooth rotation. The rotating shaft structure C6 is also a cylindrical shaft, embedded in the cylinder assembly 21 of the damping support rod mechanism 2 and the connecting rod bracket 3. Rotating shaft structures A4, B5, and C6 can also employ other existing suitable structures that can achieve the corresponding rotational connection function.

[0078] As can be seen from the above, the prosthetic knee joint of this utility model has the following beneficial effects:

[0079] 1. A triangular linkage motion mechanism is adopted, which has a simple structure. By setting the pivot structure B5 between the damping support rod mechanism 2 and the joint body 1 before and below the pivot structure A4 between the linkage bracket 3 and the joint body 1, the damping support rod mechanism 2 rotates and is stretched by tension during the leg lifting and walking process. Compared with the existing conventional design, the radial force on the damping support rod mechanism 2 is small, which can solve the problem of damage caused by excessive radial separation during the movement of the damping support rod mechanism 2.

[0080] 2. The damping support rod mechanism 2 is set as a hydraulically driven damping cylinder, and is equipped with a regulating valve 24, a standing locking mechanism 26 and other mechanisms that can adjust the damping, making it more flexible and convenient to use and with good stability.

[0081] 3. By setting a non-extension damper 28 and an extension end buffer 27 in the damping cylinder, the piston rod 22 can play a further buffering role when it retracts, so as to reduce rigid vibration and make it more stable and reliable.

[0082] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0083] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A prosthetic knee joint, comprising a joint body (1) and a damping support rod mechanism (2), the damping support rod mechanism (2) being telescopic and having a damping effect during telescopic movement, the joint body (1) being used to connect to a thigh receiving cavity, characterized in that: It also includes a linkage bracket (3), which is rotatably connected to the joint body (1) through a pivot structure A (4). The lower end of the linkage bracket (3) is used to connect to the prosthetic lower leg. The upper end of the damping support rod mechanism (2) is rotatably connected to the joint body (1) through a pivot structure B (5), and the lower end is rotatably connected to the linkage bracket (3) through a pivot structure C (6). When the prosthetic knee joint is installed on the human body and is in a standing position, the pivot structure B (5) is located in front of and below the pivot structure A (4).

2. The prosthetic knee joint according to claim 1, characterized in that: The joint body (1) is provided with a connecting cavity (11) for connecting with the thigh receiving cavity and a threaded through hole (12) located on the side wall of the connecting cavity (11).

3. The prosthetic knee joint according to claim 1, characterized in that: The lower end of the connecting rod bracket (3) is provided with a lower leg connecting clamp (31) for connecting with the lower leg of the prosthesis.

4. The prosthetic knee joint according to claim 1, characterized in that: The damping support rod mechanism (2) includes a damping cylinder, which includes a cylinder body assembly (21), a piston rod (22), and a piston head (23) fixed to the piston rod (22). The cylinder body assembly (21) of the damping cylinder is rotatably connected to the connecting rod bracket (3) through a rotating shaft structure C (6), and the piston rod (22) is rotatably connected to the joint body (1) through a rotating shaft structure B (5). Alternatively, the piston rod (22) of the damping cylinder is rotatably connected to the connecting rod bracket (3) through a rotating shaft structure C (6), and the cylinder body assembly (21) is rotatably connected to the joint body (1) through a rotating shaft structure B (5).

5. The prosthetic knee joint according to claim 4, characterized in that: The cylinder assembly (21) of the damping cylinder includes a first cylinder section (211), a second cylinder section (212), and a damping control body (213). The damping control body (213) connects the first cylinder section (211) and the second cylinder section (212) and is used to regulate the flow of fluid medium between the inner cavity of the first cylinder section (211) and the inner cavity of the second cylinder section (212). The piston head (23) is located in the second cylinder section (212). The first end of the piston rod (22) passes through the damping control body (213) and the first cylinder section (211) and extends out from the first cylinder section (211). The piston rod (22) is also provided with a fluid channel (221). The fluid channel (221) connects the space in the second cylinder section (212) located on the side of the piston head (23) with the inner cavity of the first cylinder section (211).

6. The prosthetic knee joint according to claim 5, characterized in that: The damping control body (213) has a throttle orifice connecting the inner cavity of the first cylinder (211) and the inner cavity of the second cylinder (212), and the damping control body (213) is provided with a standing locking mechanism (26) that can close or open the throttle orifice.

7. The prosthetic knee joint according to claim 5, characterized in that: The damping control body (213) has a throttle orifice connecting the inner cavity of the first cylinder (211) and the inner cavity of the second cylinder (212), and the damping control body (213) is provided with a control valve (24) that can control the opening and closing size of the throttle orifice.

8. The prosthetic knee joint according to claim 5, characterized in that: The fluid passage (221) in the piston rod (22) extends axially and penetrates the tail end face of the piston rod (22) located in the second cylinder (212). The damping cylinder also includes a non-stretching damper (28) located at the tail end of the second cylinder (212). The first end of the non-stretching damper (28) is provided with a tapered part (281) that cooperates with the fluid passage (221). The non-stretching damper (28) is provided with an oil inlet channel (282) that extends axially to its first end face, and an oil inlet (283) that connects the oil inlet channel (282) and the inner cavity of the second cylinder (212) is provided on one side of the tail end of the tapered part (281). When the piston rod (22) retracts into the cylinder assembly (21), the fluid passage (221) can be fitted onto the tapered part (281) and the two abut against each other.

9. The prosthetic knee joint according to claim 8, characterized in that: The damping cylinder also includes an adjusting bolt (29), which is screwed to the second cylinder part (212), and the non-stretching damper (28) is fixed on the adjusting bolt (29).

10. The prosthetic knee joint according to claim 4, characterized in that: The piston rod (22) is fitted with an extension end buffer (27) on the section extending out of the cylinder assembly (21), and a limiting surface is provided on the piston rod (22) that abuts against the head end of the extension end buffer (27).

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