CN114129320A - A two-degree-of-freedom passive flexible prosthetic ankle joint based on parallel mechanism - Google Patents

Abstract

Translated fromChinese

本发明公开了一种基于并联机构的双自由度被动柔性假肢踝关节，包括4‑4R并联机构、四棱台、四棱台连接件、聚氨酯橡胶块和假脚，四棱台设置在4‑4R并联机构上部，4‑4R并联机构通过四棱台与膝下截肢患者的金属腿管连接，四棱台连接件设置在4‑4R并联机构下部，4‑4R并联机构通过四棱台连接件与假脚连接，聚氨酯橡胶块设置在4‑4R并联机构内部；本发明具有结构紧凑、体积小、质量轻的特点；与普通固定踝或传统被动踝关节相比，聚氨酯橡胶块在行走过程中可以提供相当程度的弯曲扭矩；4‑4R并联机构的运动转台具有半径等长球面运动的特性，可提供双自由度转动；因此，本发明的双自由度被动柔性假肢踝关节可以有效地提高截肢患者在不平路面的行走适应性与舒适性。

The invention discloses a two-degree-of-freedom passive flexible prosthetic ankle joint based on a parallel mechanism, comprising a 4-4R parallel mechanism, a quadrangular platform, a quadrangular platform connector, a polyurethane rubber block and a prosthetic foot. The upper part of the 4-4R parallel mechanism, the 4-4R parallel mechanism is connected to the metal leg tube of the patient with amputation below the knee through the quadrangular platform, the quadrangular platform connecting piece is arranged at the lower part of the 4-4R parallel mechanism, and the 4-4R parallel mechanism is connected to the 4-4R parallel mechanism through the quadrangular platform connecting piece. The prosthetic foot is connected, and the polyurethane rubber block is arranged inside the 4-4R parallel mechanism; the invention has the characteristics of compact structure, small volume and light weight; compared with the ordinary fixed ankle or the traditional passive ankle joint, the polyurethane rubber block can be Provides a considerable degree of bending torque; the motion turntable of the 4‑4R parallel mechanism has the characteristics of spherical motion with equal lengths of radius, and can provide rotation with two degrees of freedom; therefore, the two-degree-of-freedom passive flexible prosthetic ankle joint of the present invention can effectively improve amputee patients. Walking adaptability and comfort on uneven roads.

Description

Double-freedom passive flexible artificial limb ankle joint based on parallel mechanism

Technical Field

The invention belongs to the technical field of rehabilitation aids, and particularly relates to a double-freedom-degree passive flexible artificial limb ankle joint based on a parallel mechanism.

Background

As a rehabilitation device, an ankle joint prosthesis can meet daily use requirements of patients with lower limb disabilities, the ankle joint prosthesis can be generally divided into an active type and a passive type, the active ankle joint is an ankle joint with extra torque supply, and can be generally divided into an electric type, a hydraulic type or a pneumatic type according to energy sources, the ankle joint can reduce energy consumption of amputees and provide good gait control, literature research shows that the existing active ankle joint is not compact enough, large in occupied space and large in mass, the rotation center of the ankle joint is higher than the ground, and meanwhile, the ankle joint prosthesis is high in price and can be born by a plurality of disabled patients.

Although the passive ankle joint does not have the defects of self-adjusting gait, incapability of providing moment and the like, the passive ankle joint has the characteristics of light weight, simple structure and labor saving in wearing, and the price is more easily accepted by the public compared with the active ankle joint prosthesis, but according to documents and market survey, most of the current passive ankle joint prostheses are of a single-rotation-shaft structure and only can provide the rotation freedom degrees of toe bending and dorsiflexion actions, so that the passive ankle joint cannot be well adapted to uneven road surfaces, and great limitation is brought to daily use of amputees.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a two-degree-of-freedom passive flexible artificial limb ankle joint based on a parallel mechanism.

A two-degree-of-freedom passive flexible artificial limb ankle joint based on a parallel mechanism comprises a 4-4R parallel mechanism, a quadrangular frustum pyramid connecting piece, a polyurethane rubber block and a prosthetic foot, wherein the quadrangular frustum pyramid is arranged at the upper part of the 4-4R parallel mechanism, the 4-4R parallel mechanism is connected with a metal leg tube of an amputation patient under the knee through the quadrangular frustum pyramid, the quadrangular frustum connecting piece is arranged at the lower part of the 4-4R parallel mechanism, the 4-4R parallel mechanism is connected with the prosthetic foot through the quadrangular frustum pyramid connecting piece, and the polyurethane rubber block is arranged inside the 4-4R parallel mechanism;

the 4-4R parallel mechanism comprises eight L-shaped connecting rods, four V-shaped connecting rods, a moving rotary table and a base, wherein two ends of each V-shaped connecting rod are respectively hinged with one L-shaped connecting rod through a rotating joint, the free end of one L-shaped connecting rod is hinged with the moving rotary table through a rotating joint, the free end of the other L-shaped connecting rod is hinged with the base through a rotating joint, the four V-shaped connecting rods are distributed around the moving rotary table and the base at 90 degrees, the upper ends and the lower ends of polyurethane rubber blocks are respectively embedded in central holes of the moving rotary table and the base, and adjacent bolt holes on the moving rotary table and the base are vertically distributed at 90 degrees;

specifically, the quadrangular frustum pyramid is fixedly connected with the motion turntable through four inner hexagonal bolts, the quadrangular frustum pyramid is fixedly connected with a crus leg tube of a below-knee amputation patient through a connecting piece, and the quadrangular frustum pyramid connecting piece is fixedly connected with the artificial foot through bolts;

the rotary joint comprises a boss bolt, two nylon gaskets and an oil-free lining;

specifically, the moving turntable is hinged with the L-shaped connectingrod 1 through a rotary joint, the oilless bushing is arranged at the end part of the L-shaped connecting rod in an interference fit manner, and the boss bolt firstly penetrates through the two nylon gaskets and then penetrates through the oilless bushing to be in threaded connection with the moving turntable; the base is hinged with the L-shaped connecting rod through a rotating joint, the oil-free bushing is arranged at the end part of the L-shaped connecting rod in an interference fit manner, and the boss bolt firstly penetrates through the two nylon gaskets and then penetrates through the oil-free bushing to be in threaded connection with the base; meanwhile, the front end of a boss bolt in threaded connection with the rotary table and the base can penetrate through the rotary table and the base, and plays a role in fixing and clamping a polyurethane rubber block embedded in the central holes of the movable rotary table and the base; the V-shaped connecting rod is hinged with the L-shaped connecting rod through a rotary joint, the oilless bushing is arranged at the end part of the V-shaped connecting rod in an interference fit manner, and the boss bolt firstly penetrates through the two nylon gaskets and then penetrates through the oilless bushing to be in threaded connection with the end part of the L-shaped connecting rod;

the prosthetic foot may be a carbon fiber foot plate or a cosmetic foot.

The working principle and the process of the invention are as follows:

when the artificial limb ankle joint is away from the ground, the polyurethane rubber block can be quickly restored to the initial state to prepare for landing of the next artificial foot;

when doing dorsiflexion/toe flexion movement, the quadrangular platform fixedly connected with the movement rotary table forms dorsiflexion movement relative to the advancing direction of the artificial foot, and vice versa, when doing varus/valgus movement, the quadrangular platform fixedly connected with the movement rotary table forms varus movement relative to the advancing direction of the artificial foot, and vice versa, therefore, the passive flexible artificial ankle joint can realize movement with two degrees of freedom.

The invention has the beneficial effects that:

1 the invention adopts a 4-4R parallel mechanism and a polyurethane rubber block to form a passive flexible artificial limb, and has the characteristics of compact structure, small volume and light weight; meanwhile, compared with a common fixed ankle or a traditional passive ankle joint, the polyurethane rubber block can provide a certain bending torque during walking; secondly, a motion turntable of the 4-4R parallel mechanism has the characteristic of spherical motion with equal radius and the like, and can provide two-degree-of-freedom rotation; therefore, the two-degree-of-freedom passive flexible artificial limb ankle joint can effectively improve the walking adaptability and comfort of the amputee on uneven road surfaces.

2 the ankle joint rotation center of the invention is the geometric center of the 4-4R parallel mechanism, therefore, the invention has the characteristic of lower rotation center, namely, the height of the rotation center is close to the ankle joint rotation center of healthy people, thereby better meeting the walking requirement of people and leading the gait to be more coordinated.

Drawings

FIG. 1 is an isometric view of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a rear view of the present invention;

FIG. 4 is a schematic view of the connections between the links and the moving turret/base of the present invention;

FIG. 5 is a top view of the arrangement of the inner urethane rubber blocks of the present invention;

FIG. 6 is a schematic view of the 4-4R parallel mechanism of the dorsiflexion/toe flexion motion of the present invention;

figure 7 is a schematic view of the 4-4R parallel mechanism of varus/valgus movement of the present invention.

Detailed Description

Referring to fig. 1 to 7, a two-degree-of-freedom passive flexible artificial limb ankle joint based on a parallel mechanism comprises a 4-4R parallel mechanism, aquadrangular frustum pyramid 5, a quadrangular frustumpyramid connecting piece 6, apolyurethane rubber block 7 and aprosthetic foot 8, wherein thequadrangular frustum pyramid 5 is arranged at the upper part of the 4-4R parallel mechanism, the 4-4R parallel mechanism is connected with a metal leg tube of a below-knee amputation patient through thequadrangular frustum pyramid 5, the quadrangular frustumpyramid connecting piece 6 is arranged at the lower part of the 4-4R parallel mechanism, the 4-4R parallel mechanism is connected with theprosthetic foot 8 through the quadrangular frustumpyramid connecting piece 6, and thepolyurethane rubber block 7 is arranged inside the 4-4R parallel mechanism;

the 4-4R parallel mechanism comprises eight L-shaped connectingrods 1, four V-shaped connectingrods 2, a moving rotary table 3 and abase 4, wherein two ends of each V-shaped connectingrod 2 are respectively hinged with one L-shaped connectingrod 1 through a rotary joint, the free end of one L-shaped connectingrod 1 is hinged with the moving rotary table 3 through a rotary joint, the free end of the other L-shaped connectingrod 1 is hinged with thebase 4 through a rotary joint, the four V-shaped connectingrods 2 are distributed around the moving rotary table 3 and thebase 4 at 90 degrees, the upper end and the lower end of apolyurethane rubber block 7 are respectively embedded in central holes of the moving rotary table 3 and thebase 4, and adjacent bolt holes on the moving rotary table 3 and thebase 4 are vertically distributed at 90 degrees;

specifically, thequadrangular frustum pyramid 5 is fixedly connected with themotion turntable 3 through four inner hexagonal bolts, thequadrangular frustum pyramid 5 is fixedly connected with a crus leg tube of a below-knee amputation patient through a connecting piece, and the quadrangular frustumpyramid connecting piece 6 is fixedly connected with aprosthetic foot 8 through a bolt;

the rotary joint comprises aboss bolt 31, twonylon gaskets 32 and an oil-free bushing 33;

specifically, the movingturntable 3 is hinged with the L-shaped connectingrod 1 through a rotary joint, theoilless bush 33 is arranged at the end part of the L-shaped connectingrod 1 in an interference fit manner, and theboss bolt 31 firstly penetrates through the twonylon gaskets 32 and then penetrates through theoilless bush 33 to be in threaded connection with the movingturntable 3; thebase 4 is hinged with the L-shaped connectingrod 1 through a rotary joint, theoilless bushing 33 is arranged at the end part of the L-shaped connectingrod 1 in an interference fit manner, and theboss bolt 31 firstly penetrates through the twonylon gaskets 32 and then penetrates through theoilless bushing 33 to be in threaded connection with thebase 4; meanwhile, the front end of aboss bolt 31 which is in threaded connection with the rotary table 3 and thebase 4 can penetrate through the rotary table 3 and thebase 4, and plays a role in fixing and clamping thepolyurethane rubber block 7 which is embedded in the central holes of the rotary table 3 and thebase 4; the V-shaped connectingrod 2 is hinged with the L-shaped connectingrod 1 through a rotary joint, theoilless bushing 33 is arranged at the end part of the V-shaped connectingrod 2 in an interference fit mode, and theboss bolt 31 firstly penetrates through the twonylon gaskets 32 and then penetrates through theoilless bushing 33 to be in threaded connection with the end part of the L-shaped connectingrod 1;

theprosthetic foot 8 may be a carbon fiber foot plate or a cosmetic foot.

The working principle and the process of the invention are as follows:

referring to fig. 1 to 7, in use, the 4-4R parallel mechanism composed of the L-shaped link 1, the V-shaped link 2, themotion turntable 3 and thebase 4 has the ability of equal-length radius spherical motion, when an amputee patient wears the flexible passive ankle joint of the present invention and stands, the weight of the amputee leg is borne by the 4-4R parallel mechanism, when theartificial foot 8 touches the ground in preparation for walking, the center of gravity moves, thequadrangular platform 5 connected to the lower leg tube of the patient bends relative to the rotation center of the ankle joint within the range allowed by the 4-4R parallel mechanism, and at this time, thepolyurethane rubber 7 bends passively to generate a corresponding bending torque, and when the artificial ankle joint leaves the ground, thepolyurethane rubber 7 rapidly returns to the initial state to prepare for landing of the nextartificial foot 8;

when doing dorsiflexion/toe flexion movement, thequadrangular prism 5 fixedly connected with the movingturntable 3 forms dorsiflexion action relative to the advancing direction of theartificial foot 8, and vice versa, when doing varus/valgus movement, thequadrangular prism 5 fixedly connected with the movingturntable 3 forms varus action relative to the advancing direction of theartificial foot 8, and vice versa, therefore, the passive flexible artificial ankle joint of the invention can realize movement with two degrees of freedom.

Claims (3)

Translated fromChinese

1.一种基于并联机构的双自由度被动柔性假肢踝关节，其特征在于：包括4-4R并联机构、四棱台(5)、四棱台连接件(6)、聚氨酯橡胶块(7)和假脚(8)，四棱台(5)设置在4-4R并联机构上部，4-4R并联机构通过四棱台(5)与膝下截肢患者的金属腿管连接，四棱台连接件(6)设置在4-4R并联机构下部，4-4R并联机构通过四棱台连接件(6)与假脚(8)连接，聚氨酯橡胶块(7)设置在4-4R并联机构内部；1. a two-degree-of-freedom passive flexible prosthetic ankle joint based on a parallel mechanism, characterized in that: comprising a 4-4R parallel mechanism, a quadrangular platform (5), a quadrangular platform connector (6), a polyurethane rubber block (7) and the prosthetic foot (8), the quadrangular platform (5) is arranged on the upper part of the 4-4R parallel mechanism, and the 4-4R parallel mechanism is connected with the metal leg tube of the amputee patient under the knee through the quadrangular platform (5). 6) be arranged at the lower part of the 4-4R parallel mechanism, the 4-4R parallel mechanism is connected with the prosthetic foot (8) through the quadrangular platform connecting piece (6), and the polyurethane rubber block (7) is arranged inside the 4-4R parallel mechanism;所述4-4R并联机构包括八个L型连杆(1)、四个V型连杆(2)、运动转台(3)和基座(4)，V型连杆(2)两端通过转动关节各铰接一个L型连杆(1)，其中一个L型连杆(1)的自由端通过转动关节与运动转台(3)铰接，另一个L型连杆(1)的自由端通过转动关节与基座(4)铰接，四个V型连杆(2)围绕运动转台(3)和基座(4)呈90度分布，聚氨酯橡胶块(7)上下两头分别内嵌于运动转台(3)和基座(4)的中心孔中，运动转台(3)和基座(4)上相邻的螺栓孔呈90度垂直布置。The 4-4R parallel mechanism includes eight L-shaped connecting rods (1), four V-shaped connecting rods (2), a moving turntable (3) and a base (4), and both ends of the V-shaped connecting rods (2) pass through Each of the rotating joints is hinged with an L-shaped connecting rod (1), the free end of one L-shaped connecting rod (1) is hinged with the moving turntable (3) through the rotating joint, and the free end of the other L-shaped connecting rod (1) is rotated by rotating The joint is hinged with the base (4), the four V-shaped links (2) are distributed at 90 degrees around the motion turntable (3) and the base (4), and the upper and lower ends of the polyurethane rubber block (7) are respectively embedded in the motion turntable ( 3) In the center hole of the base (4), the adjacent bolt holes on the moving turntable (3) and the base (4) are vertically arranged at 90 degrees.2.根据权利要求1所述的一种基于并联机构的双自由度被动柔性假肢踝关节，其特征在于：所述转动关节包括凸台螺栓(31)、两个尼龙垫片(32)和无油衬套(33)。2. A dual-degree-of-freedom passive flexible prosthetic ankle joint based on a parallel mechanism according to claim 1, wherein the rotating joint comprises a boss bolt (31), two nylon spacers (32) and a Oil bushing (33).3.根据权利要求1所述的一种基于并联机构的双自由度被动柔性假肢踝关节，其特征在于：所述假脚(8)可以为碳纤维脚板或者为美容脚。3 . The two-degree-of-freedom passive flexible prosthetic ankle joint based on a parallel mechanism according to claim 1 , wherein the prosthetic foot ( 8 ) can be a carbon fiber foot plate or a cosmetic foot. 4 .

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