CN106109181B

CN106109181B - Reduction exoskeleton joint and exoskeleton power assisting device thereof

Info

Publication number: CN106109181B
Application number: CN201610281597.0A
Authority: CN
Inventors: 袁博; 姜峰; 江敏; 李佳克; 孙梓瑜
Original assignee: Chongqing Niudi Technology Development Co ltd
Current assignee: Chongqing Niu Di Technology Development Co., Ltd.
Priority date: 2016-05-03
Filing date: 2016-05-03
Publication date: 2020-04-14
Anticipated expiration: 2036-05-03
Also published as: CN106109181A

Abstract

The invention provides a reduction exoskeleton joint, which comprises a first limb and a second limb which are rotationally connected, and a reduction mechanism arranged between the first limb and the second limb, wherein the reduction mechanism provides restoring force when the first limb and the second limb are close to an upright state, so that the joint is promoted to restore the upright state, and the upright state is kept under the condition that the joint is not subjected to significant torque. The resetting mechanism can adopt a magnetic attraction element or a wedge groove structure, and also comprises an elastic energy storage mechanism which releases elasticity to assist in the process of straightening the first limb and the second limb. The elastic energy storage mechanism is a torsion spring, a tension spring, a pressure spring or an air push rod, and a limiting mechanism for limiting the rotation angle of the first limb and the second limb is arranged between the first limb and the second limb. The invention has simple structure, realizes power assistance in a mechanical mode under the condition of not consuming external energy, and can realize the reset from passive bending to active straightening.

Description

Reduction exoskeleton joint and exoskeleton power assisting device thereof

Technical Field

The invention belongs to the technical field of robot wearing equipment, and particularly relates to a reduction exoskeleton joint and an exoskeleton power assisting device thereof.

Background

The exoskeleton robot is an active mechanical system which can be worn outside a human body and adopts external energy or portable energy to perform mechanical assistance according to the motion posture of the human body or the mind of a human brain. The equipment is applied to the military field, so that soldiers can carry more weapon equipment, the movement capability of the soldiers is enhanced, and the combat capability of individual soldiers is effectively improved; in the civil field, the multifunctional vehicle can be widely applied to the conditions that heavy materials need to be carried on the back and vehicles cannot pass through, such as mountaineering, traveling, fire fighting, disaster relief and the like; in the medical field, the exoskeleton robot can also be used for assisting disabled persons and old persons to walk and helping patients who temporarily lose the motor ability to perform function recovery training. Therefore, the method has wide application prospect. As for the active exoskeleton robot, there are well known Hulc lower limb exoskeleton robots from rockschidman, usa and Xos2 whole body exoskeleton robots from Raytheon Sarcos, usa.

The active exoskeleton robot introduced above can obviously enhance the functions of human bodies, but the disadvantages are also obvious: the device needs to rely on a large number of high-precision sensors and a control computer to realize active control, so that the system is complex and has high failure rate; the complex mechanical structure and high-precision components force the device to have high development cost, and limit the popularization and use of the exoskeleton machinery; and external energy sources such as batteries are needed for providing power, so that the endurance mileage of the automobile is severely limited.

Therefore, the passive exoskeleton has more popularization significance. By passive exoskeleton is meant an exoskeleton machine without an external energy source to provide additional power, and such passive exoskeletons are currently under less research. The Fortis lower extremity exoskeleton from rockschidmaster belongs to the passive exoskeleton. The device has no external energy input and power machine, and mainly has the function of transmitting the gravity of the tool held by the wearer to the ground through each link mechanism. Therefore, factory personnel can hold heavy electric or pneumatic tools for a long time with the help of Fortis to carry out large-scale equipment processing. However, the device is mainly used under the condition that a wearer stands still, and does not consider the problems that the wearer walks with load in a long distance and the human body overcomes the potential energy of the load to do work in the climbing process, so that all the moving joints of Fortis do not adopt any resetting and boosting mechanisms.

However, if a passive exoskeleton is used to assist a wearer in walking a load outdoors for a long distance, the movement joint needs to be reset and assisted. Particularly, the knee joint of the exoskeleton can efficiently transmit the gravity of a load to the ground by using a dead point principle of the hinge of the connecting rod in an upright state. However, during walking, the knee joint of the wearer is always in the alternating cycle of bending and straightening, and only the knee joint on one side is straightened at any time, and the limb on the side is just the supporting leg for the human body and the load. If the exoskeleton is required to assist the load of the human body, the knee joint needing the exoskeleton can be quickly restored to the upright state when the knee joint at the side where the human body is located is straightened. The passive exoskeleton knee joint without the reset function cannot be automatically reset when the passive exoskeleton knee joint tends to be in a straight state, and the passive exoskeleton knee joint can be reset only by the operator who needs to straighten the leg joint intentionally, so that the walking gait of the human body and the bearing efficiency of the exoskeleton can be obviously influenced.

On the other hand, when a human body is wearing the passive exoskeleton to climb, if the motion joints of the exoskeleton, particularly the knee joints, have no additional assistance, the human body needs to overcome the gravitational potential energy of the load by the acting of the thigh muscles. When the weight force of the load exceeds the continuous force application range of the muscles of the human body, the fatigue speed of the muscles of the human body is obviously increased. Therefore, the passive exoskeleton joint without additional assistance can obviously reduce the effect of the passive exoskeleton on assisting the weight-bearing walking of the human body.

Disclosure of Invention

In view of the above-mentioned deficiencies of the prior art, it is an object of the present invention to provide a reduction exoskeleton joint that enables automatic reduction of the joint.

In order to achieve the above objects and other related objects, the technical solution of the present invention is as follows:

a reduction exoskeleton joint comprises a first limb and a second limb which are rotatably connected through a joint, and further comprises a reduction mechanism and a limiting structure, wherein the reduction mechanism is arranged between the first limb and the second limb, the limiting structure is used for preventing the joint from reversely rotating, the reduction mechanism provides restoring force when the first limb and the second limb are close to an upright state, so that the joint is promoted to restore the upright state, and the upright state is kept under the condition that the joint is not subjected to significant torque.

By adopting the structure, the exoskeleton joint can generate restoring force in a state close to the upright state to promote the exoskeleton joint to restore the upright state, so that self-locking of certain force can be realized when the joint is close to the upright state, and the joint can bear force efficiently; need not to carry on other energy supply mechanisms such as power again, simplified the structure greatly, need not the operator motion shank initiative with it straightens convenient operation.

Furthermore, the resetting mechanism comprises a magnet arranged on the first limb and an attraction element arranged on the second limb and capable of attracting the magnet, and when the magnet and the attraction element are closed, the first limb and the second limb are in a straightened state. The attraction element may be a metal such as steel or a magnet. The automatic reset self-locking device has the advantages of automatic reset and vertical self-locking, can adopt two stop blocks as a limiting structure, and can abut against each other when the vertical state is restored, so that the joint is prevented from reversely rotating.

Furthermore, the resetting mechanism is realized by a wedge block and wedge groove mechanism and a pressing mechanism, the directions of the wedge blocks and the wedge grooves can be parallel to the joint rotating shaft and can also be arranged in the normal plane of the joint rotating shaft, the number of the wedge blocks and the wedge grooves can be 1-3, and the wedge blocks and the wedge grooves are uniformly arranged along the tangent line of the rotating shaft. If the pressing mechanism and the wedge block are arranged on the joint head of the second limb, the corresponding wedge groove is arranged on the joint head of the first limb, and in the rotating process, the pressing mechanism enables the matching surface of the wedge block and the wedge groove to be kept close to each other, so that the first limb and the second limb rotate towards the direction tending to be upright and reset. Because the wedge block and the groove mechanism only have a single-side inclined surface, and the other surface is a vertical surface, the wedge block can only slide in the groove in one direction, and the other side only enables the wedge block to be in contact with the vertical surface of the groove, so that the first limb and the second limb can only be bent in the forward direction but not in the reverse direction, and the limiting is realized.

The elastic energy storage mechanism is arranged between the first limb and the second limb, stores energy when the first limb and the second limb are passively bent, and releases elasticity to assist in the process of straightening the first limb and the second limb.

By adopting the structure, the exoskeleton joint can return to the upright state under the action of the pretightening force of the elastic energy storage mechanism when approaching the upright state, can apply work through human muscles to passively store energy when the joint is greatly bent, and releases elastic potential energy in the joint stretching process to assist the climbing of the load of the human body. Although the total work dissipated by the human body is not reduced from the physical point of view, the maximum load of the muscle of the human body in the process of weight bearing and climbing is reduced, and the muscle over-fatigue is avoided, so that the passive power-assisted exoskeleton can reduce the physical consumption of the human body from the physiological point of view and play a role in assisting power. Not only can reset, but also can store energy and assist.

Further, the elastic energy storage mechanism is a torsion spring, the torsion spring is installed on the joint, one end of the torsion spring is abutted to the first limb, and the other end of the torsion spring is abutted to the second limb.

Furthermore, a limiting mechanism for limiting the rotation angle of the first limb and the second limb is arranged between the first limb and the second limb.

The limiting mechanism can be a sliding groove and a sliding block which are respectively arranged on the first limb and the second limb, and the first limb and the second limb can limit the exoskeleton joint to rotate within a specific angle range through the positions of two ends of the sliding groove under the cooperation effect. The specific angle range should be adapted to the rotation amplitude of the corresponding joint of the human body. Particularly, the rotation amplitude of the human knee joint is usually 0-135 degrees, wherein 0 degree means that when the thigh and the shank are in an upright state, the rotation amplitude of the corresponding exoskeleton knee joint is 0-135 degrees, and particularly, a limiting mechanism is needed to prevent the knee joint from rotating at a negative angle, namely bending forwards, so as to prevent the human knee joint from being injured.

Furthermore, elasticity energy storage mechanism is extension spring, pressure spring or air push rod, elasticity energy storage mechanism one end is fixed on first limbs, and the other end is connected with the second limbs through acting as go-between, act as go-between and pass the stay wire hole of first limbs joint head, press in the stay wire groove on second limbs joint head, the joint head of second limbs is actually the constant radius pulley with second limbs fixed connection. The tail end of the stay wire groove of the joint head of the second limb is provided with a stay wire hole, the stay wire passes through the stay wire hole of the second limb, and the stay wire is locked by the stay wire end. When the exoskeleton joint is bent, the joint head of the second limb rotates, and the elastic energy storage mechanism is stressed to store energy by stretching the pull wire; when the exoskeleton joint is straightened, the elastic energy storage mechanism retracts the pull wire, and the generated pull force and the radius of the pulley of the second limb joint head jointly determine the rotating moment of the assistance mechanism on the exoskeleton joint. Furthermore, the elastic energy storage mechanism is a tension spring, a pressure spring or an air push rod, the first end of the elastic energy storage mechanism is fixed on the first limb, a pulley is arranged on the joint head of the second limb, one end of the stay wire is fixed on the first limb, and the other end of the stay wire bypasses the pulley and is connected with the second end of the elastic energy storage mechanism.

Namely, the pull wire is wound around the pulley, two ends of the pull wire are respectively fixed on the first limb and the elastic energy storage mechanism, and when the first limb and the second limb rotate relatively, the pulley moves relative to the first limb, so that the pull wire pulls the energy storage mechanism to bear force. The pulley of the device is a movable pulley mechanism, so that the assisting degree of the elastic energy storage mechanism can be doubled. Under the action of a pressure spring and a tension spring with the same rigidity or an air push rod with the same air pressure and sectional area, the power assisting effect of the device with the movable pulley mechanism is twice as large as that of the device without the movable pulley mechanism. If a larger boosting effect is further generated under the condition of using the same elastic energy storage mechanism, a multi-stage movable pulley mechanism is needed, and meanwhile, the elastic energy storage stroke of the elastic energy storage mechanism is also multiplied.

Further, the joint head of the first limb or the second limb is in an eccentric wheel structure with variable radius. The functions of vertical reduction of the exoskeleton joints, micro assistance in small-angle bending and obvious assistance in large-angle bending are realized.

Assuming that the change curve of the outer contour radius of the eccentric wheel along with the bending angle α is determined by R (α), and the rigidity of the elastic energy storage mechanism is k, the differential form of the assisting torque received by the exoskeleton joint at any bending angle is dT ═ k R²(α) d α. therefore, when the exoskeleton joint with the eccentric wheel structure is in an arbitrary bending angle theta from the upright state, the assistance torque applied to the joint is

It can be seen that both the speed of increase dT of the assistance torque and the total value T of the assistance torque are proportional to the square of the radius of the eccentric.

The reason is that when the exoskeleton joint rotates, the stay wire is pressed on the eccentric wheel, the stretching length of the stay wire is equal to the circumference of the eccentric wheel, and the circumference of the eccentric wheel is determined by the bending angle of the joint and the radius of the eccentric wheel, so that under the same bending angle of the joint, the larger the radius of the eccentric wheel is, the larger the stretching length of the stay wire is, and the larger the deformation degree of the elastic energy storage mechanism is; meanwhile, the magnitude of the power-assisted torque of the elastic energy storage mechanism to the joint is determined by the magnitude of deformation force of the elastic energy storage mechanism and the radius of the eccentric wheel, and the larger the radius of the eccentric wheel is, the larger the power-assisted torque generated by the eccentric wheel is under the same deformation force. By utilizing the characteristics of the eccentric wheel, a nonlinear boosting effect can be generated even if a linear elastic energy storage mechanism is adopted.

The nonlinear assistance is used for assisting a human body when the human body walks with a load, the condition which needs the assistance most is a load climbing stage, and the bending angles of the knee joint and the hip joint of the human body are large at the moment. When the human body walks on a flat road with heavy load, the bending angles of the knee joints and the hip joints of the human body are smaller, and excessive assistance is not needed for each joint. More power assistance means that the human body needs to store more energy for the elastic element, and further normal gait of the human body is influenced. By means of the eccentric wheel mechanism, the non-linear power assisting effect that the power assisting effect is weak when the power assisting joint is bent at a small angle and is obviously enhanced when the power assisting joint is bent at a large angle can be achieved.

Furthermore, the profile curve of the eccentric wheel can be formed by combining two concentric circles with different radiuses and a smooth transition curve between the two circles. When the joint is in an upright state, the stay wire is pressed on the outer contour of the small-radius circle; until the bending angle of the joint is reached

Then, the pull wire is pressed on a smooth curve transiting between the two concentric circles; the joint is continuously bent, and the pull wire is pressed on the outer contour of the large-radius circle. By adopting the eccentric wheel with the combined concentric circle profile, the exoskeleton joint has an obvious two-section type power assisting effect. At a bending angle smaller than

When the exoskeleton joint has weak assistance effect, the elastic energy storage mechanism of the joint has an upright resetting function, so that the exoskeleton joint basically does not have obvious assistance to the joint and does not have obvious influence on human gait; when the bending angle of the joint is larger than

After that, the power-assisted effect of the exoskeleton joint is obvious, and the movement of the joint is obviousThe one-step bending needs the human body to do work to realize the energy storage of the elastic mechanism, and then the elastic energy storage mechanism can provide extra assistance torque for the joint when the joint is straightened.

Further, the profile curve of the eccentric wheel can also adopt an involute form. When the eccentric wheel of the exoskeleton joint is in an upright state, the profile of the eccentric wheel pressed by the pull wire has the minimum radius; as the bending angle is increased, the contour radius of the eccentric wheel pressed by the pull wire is gradually increased along with the bending angle in an involute form. The eccentric wheel in the involute form has no obvious sectional type assistance effect, but has weak assistance effect when the joint is bent at a small angle, and the assistance effect is gradually obvious and continuously enhanced when the bending angle is larger.

The profile curve of the eccentric wheel can also be in other various gradual change curve forms, and the nonlinear boosting effect of the eccentric wheel can be represented by a formula

And (6) performing prediction.

Furthermore, when the tension spring and the pressure spring adopt a nonlinear spring as an energy storage mechanism, the adjusting device can be pre-tightened by the spring; when high-pressure gas is used as the energy storage mechanism, the initial air pressure can be changed, so that the boosting adjustment in different degrees can be realized. The different degrees of assistance adjustment refer to that the assistance size of the passive exoskeleton joint can be correspondingly adjusted under the condition that the wearer bears different degrees of loads. The power assisting device has the advantages that when a wearer bears a light load, a small power assisting effect can be adopted, so that the energy storage degree of the power assisting device is small when the wearer bends legs during walking, and the wearer can walk easily; and when the wearer bears heavier burden, then can adopt great helping hand effect, though the curved leg in-process wearer of walking at every turn all needs great power to carry out the energy storage to elastic mechanism like this, but the helping hand degree that straight leg in-process elasticity energy storage equipment provided is also great, and the wearer just can effective helping hand at the in-process of climbing bearing heavier burden like this.

The non-linear spring refers to an irregular spring in which different spring pitches, spring diameters or spring wire diameters exist in a single spring. The elastic stiffness of the non-linear spring is increased along with the increase of the deformation degree, so that the change curve of the elastic force is non-linear. The spring pre-tightening adjusting device changes the initial deformation degree of the spring by changing the position of the spring supporting end, and further changes the pre-tightening force of the spring. For the torsion spring structure, the spring support end can be a spring mounting groove of the first limb or the second limb; for the pressure spring structure, the spring support end is a spring end close to the exoskeleton joint; for the tension spring configuration, the spring support end is the spring end away from the exoskeleton joint.

Furthermore, the spring pre-tightening adjusting device can be of a snap spring sliding groove structure, and the snap spring is connected with the spring supporting end and can move in the sliding groove. The slotting direction of the sliding groove is the same as the deformation direction of the spring, namely the torsion spring is along the rotation direction of the exoskeleton joint; the compression spring or the tension spring is arranged along the compression or stretching direction, and the direction of the sliding groove is the same as the axial direction of the connecting rod because the compression spring and the tension spring are usually coaxially arranged in the connecting rod. Open on the spout has a plurality of levels gear fixed slots, and the card bamboo shoot can block into corresponding gear fixed slot when sliding to arbitrary level gear through the spout to under the condition that does not have artificial effort, the card bamboo shoot can not break away from the fixed slot, has just realized the spring pretension adjusting device who has different gears from this.

Further, for a pressure spring or tension spring structure, the spring pre-tightening adjusting device can also be realized by a screw rod sliding block structure. The sliding block is a spring supporting end, an opening is formed in the axial center of the sliding block, a screw opening matched with the lead screw is formed in the sliding block, a spline is arranged on the outer side of the spring supporting end and matched with a key groove in the inner side of the connecting rod, and the sliding block can only move linearly along the axial direction of the connecting rod and cannot rotate together with the lead screw. The lead screw and the spring are coaxially arranged in the connecting rod, one end of the lead screw is provided with a bevel gear or worm gear structure which can be matched with a bevel gear or worm structure on a pretightening force adjusting knob perpendicular to the connecting rod, and the other end of the lead screw is matched with a screw opening of the spring supporting seat. When the pretightening force adjusting knob drives the bevel gear or the worm to rotate, the lead screw can be driven to rotate, and then the spring supporting seat is driven to move along the compression or relaxation direction of the spring, so that the pretightening force adjusting function of the spring is realized.

The invention also provides an exoskeleton power assisting device which comprises the passive power assisting exoskeleton joint, wherein the first limb is a thigh bone, the second limb is a shank bone, the lower end of the shank bone is connected with an elastic foot support, the upper end of the thigh bone is connected with the waist connecting rod through a joint bearing, three rotational degrees of freedom are provided, and flexion, extension, lateral swing and rotational movement of a hip joint are respectively realized. Of course other existing structures, etc. are also included.

As mentioned above, the beneficial effects of the invention are: the device adopts a passive energy storage mechanism for assisting, so that compared with all existing hydraulic, pneumatic and motor active assisting technologies, the device is simpler and more reliable, has low cost and realizes light weight.

The device can realize the joint limiting function by adopting a sliding groove and sliding block mechanism, can also realize the vertical resetting and self-locking functions of the joint by adopting a magnetic mechanism or a wedge groove mechanism, and can realize the passive assistance of the joint by adopting energy storage mechanisms such as a spring or an air push rod and the like. And the eccentric wheel mechanism is adopted to realize nonlinear boosting under different bending angles, and the force adjustment of the boosting mechanism is realized in a spring pre-tightening or cylinder pressure adjusting mode.

Drawings

FIG. 1 is an exploded view of the magnetic reset mechanism used in example 1;

FIG. 2 is an installed cross-sectional view of FIG. 1;

FIG. 3 is an exploded view showing radial compression and restoration by a wedge mechanism in example 2;

FIG. 4 is an installed cross-sectional view of FIG. 3;

FIG. 5 is an exploded view of the axial compression resetting by the wedge mechanism in example 3;

FIG. 6 is an exploded view of the other side of example 3;

FIG. 7 is a schematic sectional view of embodiment 3;

fig. 8 and 9 are exploded views of the energy storage mechanism according to embodiment 4, which uses a torsion spring;

FIG. 10 is an exploded view showing the elastic energy accumulating mechanism of embodiment 5 using a compression spring;

FIG. 11 is a cross-sectional view of FIG. 10;

FIG. 12 is an exploded view showing the elastic energy accumulating mechanism of example 5 using a tension spring;

FIG. 13 is a cross-sectional view of FIG. 12;

FIG. 14 is an exploded view showing the elastic energy accumulating mechanism of example 5 using an air ram;

FIG. 15 is a cross-sectional view of FIG. 14;

FIG. 16 is an exploded view showing the structure of an eccentric wheel and a stopper mechanism according to example 6;

FIG. 17 is a schematic structural view of the reaction limiting groove and the limiting bump in FIG. 16;

fig. 18 is a cross-sectional view of fig. 16.

FIG. 19 is an exploded view showing an involute eccentric wheel structure and a stopper mechanism according to embodiment 6;

FIG. 20 is a cross-sectional view of FIG. 19;

FIG. 21 is a schematic structural view of the reaction limiting recess and the limiting projection of FIG. 19;

FIG. 22 is an exploded perspective view showing the construction of the movable pulley and the wire in example 7;

FIG. 23 is a cross-sectional view of FIG. 22;

FIG. 24 is an exploded view of the torsion spring of embodiment 8 as an elastic energy storage mechanism, with the catch mechanism as the preload adjustment mechanism;

FIG. 25 is an assembly view of FIG. 24;

FIG. 26 is a schematic view of an embodiment 8 in which a spring is used as the elastic energy storage mechanism, and a catch mechanism is used as the preload adjustment device;

FIG. 27 is a schematic diagram of an embodiment 8 in which a compression spring is used as the elastic energy storage mechanism, and a lead screw and a worm gear are used as the preload adjusting device;

FIG. 28 is a cross-sectional view of the internal structure of FIG. 27;

FIG. 29 is a schematic view of a torsion spring in accordance with embodiment 8, employing a lead screw and a bevel gear pair as a preload adjustment apparatus;

FIG. 30 is a schematic structural view of an exoskeleton force assisting device in embodiment 9;

FIG. 31 is a schematic view showing the elastic energy storing mechanism of example 9 mounted on the lower leg bone;

FIG. 32 is a schematic view showing the structure in which the elastic energy storing mechanism of embodiment 9 is installed in the lumbar connecting rod;

FIG. 33 is an exploded view of the hip joint in example 9;

FIG. 34 is a cross-sectional view of FIG. 33;

fig. 35 is a power assisting curve measured by experiments when a pulley with equal radius and an eccentric wheel are respectively adopted as joint heads.

Description of reference numerals

1 first limb

11 joint head

12 magnet

13 stop block

14 connecting rod

15 mounting port

16 tension spring pin

17 air inflating hole

18 spacing groove

19-line hole

2 second limb

21 joint head

22 suction element

23 stop dog

24 movable pulley

25 wire drawing groove

26 support shaft

27 stop block

28 connecting hole

31 spring

32 wedge block

33 wedge groove

34 pressing cover

35 wedge disc

36 convex platform

40 spline

41 torsion spring

42 adjusting knob

43 adjusting groove

44 fixed groove

45 pull wire

46 kahu bamboo shoot

47 pressure spring

48 briquetting

49 support seat

50 key groove

51 worm

52 worm wheel

53 leading screw

54 knob

55 bevel gear pair

56 tension spring

57 pull ring

58 air push rod

59 piston

61 thigh bone

62 shank skeleton

63 elastic support

64 waist connecting rod

65 hip joint

66 thigh joint end

67 waist joint end

68 oscillating bearing

69 backpack support frame

71 bearing

72 bolt

73 nut

74 shim

75 shaft sleeve

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Example 1

As shown in fig. 1 and 2, a reduction exoskeleton joint comprises a first limb 1 and a second limb 2, in this example, a knee joint is taken as an example for description, wherein the first limb 1 corresponds to an upper joint, the second limb 2 corresponds to a lower joint,

joint heads

11 and 21 of the first limb 1 and the second limb 2 are rotatably connected through a bearing 71, a bolt 72 and a nut 73, and in order to enable the first limb 1 and the second limb 2 to rapidly reduce when the first limb 1 and the second limb 2 tend to be upright, a reduction mechanism is arranged between the first limb 1 and the second limb 2 in this example. In this embodiment, a magnet attraction mechanism is used for resetting, that is, a magnet 12 is disposed on the first limb 1, and an attraction element 22 attracted to the magnet 12 is disposed on the second limb 2 for attraction, where the attraction element 22 may be a steel column, an iron column, or a magnet. The magnet 12 and the attraction element 22 are mounted in mounting slots provided in the first limb 1 and the second limb 2. In order to prevent the joint from rotating in the opposite direction, the first limb 1 and the second limb 2 are provided with

stops

13, 23 opposite each other, which abut when rotated to the upright position, in this case also mounting grooves are provided in the

stops

13, 23, so that the magnet 12 and the attraction element 22 can be brought towards each other and close.

Example 2

As shown in fig. 3 and 4, in this example, the joint heads 11 and 21 of the first limb 1 and the second limb 2 are rotatably connected through a bearing 71, a bolt 72 and a nut 73, in order to allow a quick reduction of the first limb 1 and the second limb 2 when they are in a position of standing, a reduction mechanism is provided in this case between the first limb 1 and the second limb 2, which comprises a spring 31 as a pressing mechanism, a wedge 32 and a wedge groove 33 which are matched, wherein the spring 31 applies elastic force to the wedge 32 from the radial direction of the joint, wherein the spring 31 is vertically arranged in a groove arranged on the second limb 2, the wedge groove 33 is arranged on the arc-shaped expanding surface of the joint head 11 of the first limb 1, the wedge 32 is positioned above the spring 31 and is tightly pressed in the wedge groove 33, vertical pressure is converted into tangential acting force of the wedge groove 33 through the inclined matching surfaces of the wedge groove 33 and the wedge block 32, so that the joint can be automatically reset when the joint is approximately upright. Wherein the higher side of the wedge 32 is pressed against the side wall of the wedge groove 33 to prevent the joint from reversing.

Example 3

In this example, the restoration was also performed by a slope fitting method, and unlike example 2, the urging direction of the pressing mechanism was parallel to the joint axis. As shown in fig. 5 to 7, an inclined mating surface in the rotation direction is formed between the joint heads of the first limb 1 and the second limb 2, and the first limb 1 and the second limb 2 are laterally compressed by a tightening or compressing mechanism, and during the return after bending, the force of the tightening or compressing mechanism is applied to the inclined surface to move the first limb 1 and the second limb 2 along the inclined surface to the initial position.

In this example, the centers of the joint heads 11, 21 of the first limb 1 and the second limb 2 are provided with connecting holes, the outer side of the second limb 2 is provided with a wedge disc 35, the middle part of the wedge disc 35 protrudes a boss 36 into the connecting hole 28 of the second limb 2 to match with the connecting hole through a spline and a key slot, so that the second limb 2 and the wedge disc 35 can synchronously rotate, the spring 31 is sleeved outside the gland 34, the end surface step of the gland 34 presses one end of the spring 31, the other end of the spring 31 abuts against the inward extension part of the boss 36 of the wedge disc 35, so as to provide axial pressure for the wedge disc, the axle center of the gland 34 is also provided with the connecting hole, the bolt 72 penetrates through the joint head 11, the bearing 71, the joint head 21, the wedge disc 35 and the gland 34 and is in screwed fit with the nut 73, the gland 34 not only plays the role of pre-tightening the spring 31 under the fastening effect of the nut 73, but also abuts against the joint head 21, so, ensuring that the device does not loosen during movement. Wherein, a plurality of arc wedges 32 are arranged on the inner wall of the wedge disc 35, the side surfaces of the wedges 32 are inclined surfaces, a plurality of arc wedge grooves 33 corresponding to the wedges 32 are arranged on the inner wall of the first limb 1, and the bottom of each arc wedge groove 33 is an inclined surface matched with the wedge 32. The wedge 32 and the wedge groove 33 rotate relatively in the process of bending the joint, and the wedge 32 is reset under the action of the spring 31 in the process of straightening, so that the effect of quick reset is achieved. At the same time, the wedge 32 and the wedge groove 33 cooperate to prevent the joint from rotating in the reverse direction.

Example 4

Furthermore, in order to realize not only resetting but also a passive power assisting function, traditional active energy supply equipment such as a battery is omitted.

As shown in fig. 8 and 9, an elastic energy storage mechanism is arranged between the first limb 1 and the second limb 2, and the elastic energy storage mechanism stores energy when the first limb 1 and the second limb 2 are passively bent, and releases elastic force to assist in the process of straightening the joint formed by the first limb 1 and the second limb 2. In this embodiment, the lower end joint head of the first limb 1 and the upper end joint head of the second limb 2 are correspondingly provided with annular mounting grooves, the elastic energy storage mechanism is selected to be a torsion spring 41, the torsion spring is mounted in the annular mounting grooves, one end of the torsion spring 41 abuts against the first limb 1, and the other end of the torsion spring abuts against the second limb 2. In order to limit the rotation range, a limiting mechanism is arranged, which comprises a limiting groove 18 arranged on the joint head 11 of the first limb 1 and a limiting block 27 arranged on the joint head 21 of the second limb 2, and the rotation limitation is realized through the matching of the limiting block 27 and the limiting groove 18.

Example 5

The difference between this example and embodiment 4 is that the elastic energy storage mechanism is a tension spring, a compression spring or an air push rod, one end of the elastic energy storage mechanism is fixed on the first limb 1, the other end of the elastic energy storage mechanism is connected with the second limb 2 through a pull wire 45, the pull wire 45 is pressed on the joint head of the first limb 1 or the second limb 2, and when the joint is bent, the joint head rotates and the elastic energy storage mechanism is stressed through the pull wire 45 to store energy.

As shown in fig. 10 and 11, the elastic energy storage mechanism employs a compression spring 47, the first limb 1 is provided with a connecting rod 14, the connecting rod 14 is provided with a pressing block 48, the compression spring 47 is located between the pressing block 48 and the first limb 1, the upper end of the pull wire 45 is connected with the pressing block 48, the lower end of the pull wire 45 passes through the pull wire hole 19 of the joint head 11 of the first limb 1 and is pressed in the pull wire groove on the joint head 21 of the second limb 2, and the joint head 21 of the second limb 2 is actually an equal-radius pulley fixedly connected with the second limb 2. The tail end of the stay wire groove of the joint head 21 of the second limb 2 is provided with a stay wire hole 29, and the stay wire 45 passes through the stay wire hole 29 of the second limb 2 and is locked by a stay wire end. When the exoskeleton joint is bent, the joint head 21 of the second limb 2 rotates, and the tension wire 45 is stretched to stress the compression spring 47 to store energy; when the exoskeleton joint is straightened, the tension generated by the compression spring 47 and the radius of the pulley of the joint head 21 of the second limb 2 jointly determine the rotation torque generated by the power assisting mechanism to the exoskeleton joint by retracting the pull wire. Wherein the joint heads 11, 21 are rotatably connected by a bearing 71, a bolt 72, a nut 73, a washer 74, a bushing 75, etc. The pull wire 45 may be a steel wire or a pull cable.

As shown in fig. 12 and 13, when the tension spring 56 is used as the elastic energy storage mechanism, the upper end of the tension spring 56 is hung on the tension spring pin 16 transversely inserted in the connecting rod 14, the lower end is connected with the pull ring 57 at the upper end of the pull wire 45, and the other structure is similar to that when the compression spring 47 is used as the elastic energy storage mechanism. When the initial pretightening force is adjusted, the height of the tension spring pin 16 can be changed, and the design can be carried out by referring to the height adjusting structure of the compression spring 47, which is not described one by one.

As shown in fig. 14 and 15, when the gas push rod 58 is used as the elastic energy storage mechanism, the connecting rod 14 itself forms an air storage chamber, the gas push rod 58 and the piston 59 are installed in the connecting rod 14, the air vent 17 is formed in the connecting rod 14, the lower end of the gas push rod 58 is connected with the pull wire 45, the piston 59 is located in the chamber of the connecting rod 14, energy is stored through gas pressure, initial gas pressure is changed, and initial pre-tightening force can be adjusted.

Example 6

Further, in order to prevent the joint from rotating forwards and backwards and realize joint movement limitation, a limiting mechanism for limiting the rotating angle of the first limb and the second limb is arranged between the first limb and the second limb.

As shown in fig. 16 to 18, a stopper groove 18 is formed in the joint head 11 of the first limb 1 in the rotation direction, a stopper 27 corresponding to the stopper groove 18 is provided in the joint head 21 of the second limb 2, and the rotation range of the joint is restricted by the stopper groove 18 and the stopper 27.

Meanwhile, in the embodiment, the joint head 21 adopts an eccentric wheel structure to realize nonlinear assistance, the pull wire 45 bypasses the pull wire groove 25 on the outer contour of the joint head 21, the upper end is connected with the elastic energy storage mechanism, and the lower end is fixed on the second limb 2. The nonlinear assistance is used for assisting a human body to walk with a load, and the condition needing the assistance is usually a load climbing stage, wherein the bending angles of knee joints and hip joints of the human body are large. When the human body walks on a flat road with heavy load, the bending angles of the knee joints and the hip joints of the human body are smaller, and excessive assistance is not needed for each joint. More power assistance means that the human body needs to store more energy for the elastic energy storage mechanism, and further normal gait of the human body is influenced. By means of the eccentric wheel mechanism, the non-linear power assisting effect that the power assisting effect is weak when the power assisting joint is bent at a small angle and is obviously enhanced when the power assisting joint is bent at a large angle can be achieved.

Further, the profile curve of the eccentric wheel is composed ofTwo concentric circles with different radiuses and a smooth transition curve between the two circles. When the joint is in an upright state, the pull wire is pressed on the outer contour of the small-radius circle O1; until the pull wire is pressed on the smooth curve that transits between the two concentric circles (at which time the bending angle of the joint is

) (ii) a Continuing to bend the joint, the pull wire will press against the outer contour of the large radius circle O2. By adopting the eccentric wheel with the combined concentric circle profile, the exoskeleton joint has an obvious two-section type power assisting effect. At a bending angle smaller than

And then, the power assisting effect of the exoskeleton joint is obvious, the further bending of the joint needs the human body to do work to realize the energy storage of the elastic mechanism, and the elastic energy storage mechanism can provide additional power assisting torque for the joint when the joint is straightened.

As shown in fig. 19 to 21, the profile curve a of the eccentric can also take the form of an involute. When the eccentric wheel of the exoskeleton joint is in an upright state, the profile of the eccentric wheel pressed by the pull wire 45 has the minimum radius; as the bending angle increases, the radius of the profile of the eccentric against which the tension wire 45 is pressed gradually increases in an involute form with the bending angle. The eccentric wheel in the involute form has no obvious sectional type assistance effect, but the assistance effect is weak when the joint is bent at a small angle, and the assistance effect is gradually obvious when the bending angle is larger and is continuously enhanced. In order to limit the rotation angle, a stopper groove 18 is similarly formed in the joint head 11 of the first limb 1 in the rotation direction, and a stopper 27 corresponding to the stopper groove 18 is formed in the joint head 21 of the second limb 2.

Example 7

As shown in fig. 22 and 23, one end of the elastic energy storage mechanism is fixed, the other end is movable, and is arranged in the first limb 1, the second limb 2 is provided with a support shaft 26, the support shaft 26 is provided with a movable pulley 24, one end of a pull wire 45 is fixed on the joint end surface of the first limb 1, and passes through a pull wire hole 19 in the joint head 11 of the first limb 1, then bypasses the movable pulley 24 assembled on the second limb, and is newly pulled back to the pull wire hole 19 in the first limb 1, and the other end of the pull wire 45 continues to extend to be connected with the movable end of the elastic energy storage mechanism. In this example, the limit mechanism, the pretension adjusting device, and the like can be referred to embodiments 5 and 6.

The assistance degree of the elastic energy storage mechanism can be doubled by adopting the movable pulley mechanism. Under the action of a pressure spring and a tension spring with the same rigidity or an air push rod with the same air pressure and sectional area, the power assisting effect of the device with the movable pulley mechanism is twice as large as that of the device without the movable pulley mechanism. If a larger boosting effect is further generated under the condition of using the same elastic energy storage mechanism, a multi-stage movable pulley mechanism is needed, and meanwhile, the elastic energy storage stroke of the elastic energy storage mechanism is also multiplied.

Example 8

When the torsion spring, the tension spring and the pressure spring adopt a nonlinear spring as an energy storage mechanism, the boosting force can be adjusted through the spring pre-tightening force adjusting device; when high-pressure gas is used as the energy storage mechanism, the initial air pressure can be changed, so that the boosting adjustment in different degrees can be realized. The different degrees of assistance adjustment refer to that the assistance size of the passive exoskeleton joint can be correspondingly adjusted under the condition that the wearer bears different degrees of loads. The power assisting device has the advantages that when a wearer bears a light load, a small power assisting effect can be adopted, so that the energy storage degree of the power assisting device is small when the wearer bends legs during walking, and the wearer can walk easily; and when the wearer bears heavier burden, then can adopt great helping hand effect, though the curved leg in-process wearer of walking at every turn all needs great power to carry out the energy storage to elastic mechanism like this, but the helping hand degree that straight leg in-process elasticity energy storage equipment provided is also great, and the wearer just can effective helping hand at the in-process of climbing bearing heavier burden like this.

Further, the non-linear spring refers to an irregular spring in which different spring pitches, spring diameters, or spring wire diameters exist in a single spring. The elastic stiffness of the non-linear spring is increased along with the increase of the deformation degree, so that the change curve of the elastic force is non-linear. The spring pre-tightening adjusting device changes the initial deformation degree of the spring by changing the position of the spring supporting end, and further changes the pre-tightening force of the spring. For the torsion spring structure, the spring support end can be a spring mounting groove of the first limb or the second limb; for the pressure spring structure, the spring support end is a spring end close to the exoskeleton joint; for the tension spring configuration, the spring support end is the spring end away from the exoskeleton joint.

On the basis of embodiment 4, in this example, to achieve a better adaptation effect, an adjusting device for the pre-tightening force of the torsion spring is provided, as shown in fig. 24 and 25, in this example, a structure of a snap 46 and an adjusting groove 43 is provided, namely, an adjusting groove 43 is arranged along the rotation direction of the exoskeleton joint, a multi-stage gear fixing groove 44 is arranged on the adjusting groove 43, the snap bamboo 46 can be snapped into the corresponding gear fixing groove 44 when sliding to any stage gear through adjustment, and under the condition of no artificial acting force, the snap catches 46 can not be separated from the fixing grooves 44, thereby realizing the pretightening force adjustment with different gears, wherein the snap 46 is formed by bending one end of the torsion spring 41, the bending section is parallel to the axis of the rotation, extends out of the adjusting groove 43 and is sleeved with an adjusting button 42 for shifting, according to the difference of the assistance force required by load, the position of the adjusting button 42 is shifted to realize the adjustment of the initial pretightening force. The rotation limitation is realized by matching the limiting block 27 with the limiting groove 18.

As shown in fig. 26, in addition to embodiment 5, in order to satisfy the adjustment of the initial preload, an adjusting groove 43 and a multi-stage fixing groove 44 are formed along the axial direction of the connecting rod 14, the locking catch 46 is disposed on a supporting seat 49, the lower end of the compression spring 47 is supported on the supporting seat 49, and the upper end is pressed by the pressing block 48. The initial pre-tightening force is adjusted by shifting the position of the catch 46 up and down.

As shown in fig. 27 and 28, the pretightening force adjusting device may be of a screw rod slider structure, a screw rod 53 and a pressure spring 47 are coaxially installed in the connecting rod 14, a base of the screw rod 53 is supported in a corresponding matching hole on the first limb 1 and can rotate, a through hole is formed in the axis of the screw rod 53 for passing through a pull wire 45, a spline 40 is formed on the side wall of the supporting seat 49 and is matched with a key groove 50 on the inner wall of the connecting rod 14, so that the supporting seat 49 is limited to slide only along the axial direction of the connecting rod 14, a screw hole matched with the screw rod 53 is formed in the inner hole of the supporting seat; the device also comprises a driving mechanism for driving the screw 53 to rotate, in this example, a worm gear mechanism is adopted, a worm gear 52 is coaxially fixed with the screw 53, the worm 51 is installed in the installation opening 15 formed in the connecting rod 14, the outer end of the worm is connected with a knob 54, and the axial position adjustment of the supporting seat 49 can be realized by rotating the knob 54, so that the adjustment of the initial pretightening force is realized.

As shown in fig. 29, the driving may be performed by a bevel gear pair 55, one of which is fixed to the lead screw 53 and the other of which is connected to the knob 54.

Example 9

As shown in fig. 30, the present invention also provides an exoskeleton power assisting device, which comprises the exoskeleton joints according to any one of the above embodiments, including thigh bones 61, shank bones 62, waist connecting rods 64 and backpack supporting frames 69, wherein the lower ends of the shank bones 62 are connected with elastic foot supports 63 made of elastic material, although springs can be used instead of the elastic foot supports, since the movable range of the ankles is large, in order to ensure the walking of human body freely without increasing too much constraint, only one elastic foot support 63 is added at the fixed bottom of the shank, so as to reduce the impact generated when the whole mechanism is in contact with the ground. The upper end of the thigh skeleton 61 is connected with the waist connecting rod 64 through a joint bearing, and the three degrees of freedom of rotation are provided, so that flexion and extension, lateral swinging and rotation of the hip joint 65 are respectively realized. Based on the complexity of the human body structure, the hip joint 65 is more flexible than other joints, one degree of freedom can not meet the requirement of mechanism movement far away, and the joint bearing is used as a connecting part, so that the hip joint 65 has 3 degrees of freedom, and the hip joint 65 can swing back and forth and comprises left and right swinging and rotating movement. The design can ensure the coordination of the mechanism, not only does not limit the movement of the human body, but also can ensure the safety performance of the movement. The thigh skeleton 61 and the shank skeleton 62 are respectively composed of two sections, a height adjusting hole is correspondingly formed between the two sections, and the two sections are fixed through a quick-release pin, so that the length of the thigh skeleton 61 and the length of the shank skeleton 62 are adjustable. The exoskeleton joint is used as a knee joint, the connecting rod 14 is used as a component of a thigh skeleton 61, and the elastic energy storage mechanism is arranged in the thigh skeleton 61. In this embodiment, the tension spring 56 is taken as an example, and other elastic energy storage mechanisms can be adopted in other embodiments.

As shown in fig. 33 and 34, the hip joint 65 includes a thigh joint end 66, a waist joint end 67 and a joint bearing 68, the joint bearing 68 is rotatably connected with the thigh joint end 66 through a bolt and a nut, the waist joint end 67 is sleeved on a rod portion of the joint bearing 68 and is fixed through a coaxially penetrating locking bolt, wherein two inner walls of the thigh joint end 66 form a conical surface structure, so that the joint bearing 68 has a degree of freedom of left-right swinging. As shown in fig. 31 and 32, the elastic energy storage means can also be arranged in the lower leg skeleton 62 or in the lumbar connection rod 64.

The exoskeleton power assisting device belongs to a passive exoskeleton device, and is simple in structure, reliable and durable; low cost, easy popularization and no need of external energy input, thereby being capable of being worn and used for a long distance. The device passes through link mechanism and shares two mechanical legs with the weight of knapsack, finally transmits to ground to alleviate operator's heavy burden, and will climb the in-process human body and need spread out the whole motion process of the leg bending and straight leg to the work that the high promotion of heavy burden needs to be done through spring energy storage device, thereby reduced the required maximum load that bears of human shank, played the effect of helping hand. Compared with the traditional passive exoskeleton, the device has the advantages of joint resetting and passive assistance. Compared with the traditional passive exoskeleton joint, the exoskeleton joint with the resetting and power assisting functions mainly has the following advantages:

(1) the joint is vertically reset and self-locked: when the exoskeleton joint tends to be in an upright state, the joint can be reset through restoring force of the magnetic attraction element or the wedge groove mechanism, and the exoskeleton joint can be kept in the upright state under the action of small external force, so that the exoskeleton joint is prevented from being unstable at an artificial dead point.

(2) Joint passive type helping hand: through the elastic energy storage mechanism, the passive power assisting of the exoskeleton joints can be realized, although the total power consumed by a human body is unchanged from the physical perspective, the elastic energy storage mechanism stores energy when the joints are bent and assists power when the joints are straightened, so that the peak value of muscle force during the climbing of the human body with load is reduced, the human body is prevented from overload movement, and the power assisting effect on the walking with load is realized. And moreover, the energy storage mechanism can be arranged in the thigh exoskeleton, the shank exoskeleton and the waist support rod by adopting the pull wire, the pulley and the linear elastic energy storage mechanism, so that the overall design of the device is more flexible.

(3) The non-linear assistance comprises that by adopting a pull wire and eccentric wheel mechanism, the exoskeleton joint can realize non-linear assistance, the effect is that when a human body walks with a load, the condition needing the most assistance is generally a load climbing stage, the bending angles of knee joints and hip joints of the human body are larger at the moment, when the human body walks with a load on a flat road, the bending angles of the knee joints and the hip joints of the human body are smaller, and each joint does not need excessive assistanceExoskeleton joint with eccentric wheel structure at bending angle α<The increasing slope of the boosting torque is gentle at 30 degrees, but α degrees>The slope of the power-assisted torque after 60 degrees is obviously steep, and 30 degrees<α<In the range of 60 deg., the increasing slope of the boosting torque gradually transits. The two-section boosting effect is in accordance with the contour characteristics of a transition curve between an inner radius circle and an outer radius circle and between the two concentric circles of the concentric circle type eccentric wheel. This means that the eccentric wheel in other forms such as involute can have different non-linear boosting effect, and the boosting torque formula derived from the above can be used

And (6) performing prediction. The theoretical curve of the eccentric wheel in fig. 34 is derived from the above formula, and it can be seen that the theory is basically consistent with the experimental curve.

(4) The boosting pre-tightening is adjustable: by adopting the nonlinear spring and the pretightening force adjusting mechanism or adopting the air push rod mechanisms with different air pressure values, the exoskeleton joint can have the assistance effects of different magnitudes aiming at loads with different degrees. Because the elastic stiffness of the nonlinear spring is changed along with the different deformation degrees, the initial force and the elastic stiffness shown by the spring mechanism are different under the action of the pretightening force adjusting mechanisms at different gears; the air push rod mechanism can achieve the effects by adjusting the air pressure value in the cavity.

The invention can be used for conveying rescue goods and can freely walk in ruins with complex terrain, so that a user can still easily finish various actions while carrying a larger mass, and rescue work on disaster sites is assisted; meanwhile, in a future battlefield, soldiers wearing the exoskeletons can have strong physical functions and strong individual combat capability.

Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A reducing exoskeleton joint comprising a first limb and a second limb rotatably connected by a joint, wherein: further comprising a return mechanism and a retaining structure disposed between the first limb and the second limb, the return mechanism providing a return force to urge the exoskeleton joints to return to an upright state when the first limb and the second limb are near the upright state, the retaining structure preventing the exoskeleton joints from counter-rotating when the exoskeleton joints return to upright; the elastic energy storage mechanism is arranged between the first limb and the second limb, stores energy when the first limb and the second limb are passively bent, and releases elasticity to assist in the process of straightening the first limb and the second limb; one end of the elastic energy storage mechanism is fixed on the first limb, the other end of the elastic energy storage mechanism is connected with the second limb through a pull wire, the pull wire is pressed on a joint head of the first limb or the second limb, and when the joint is bent, the joint head rotates and enables the elastic energy storage mechanism to be stressed through the pull wire to store energy; the joint head is of an eccentric wheel structure, the pull wire is pressed on the joint head, and the stress and the speed are increased faster when the bending angle is larger, so that the nonlinear power assistance is realized.

2. The repositioning exoskeleton joint of claim 1, wherein: the reset mechanism consists of a magnetic adsorption element.

3. The repositioning exoskeleton joint of claim 1, wherein: the resetting mechanism comprises a pressing mechanism and a wedge-groove mechanism, the wedge-groove mechanism enables an inclined matching surface to be formed between the first limb and the second limb, and the pressing mechanism enables the inclined matching surface to generate joint restoring force.

4. The repositioning exoskeleton joint of claim 1, wherein: the elastic energy storage mechanism is a tension spring, a pressure spring or an air push rod.

5. The repositioning exoskeleton joint of claim 4, wherein: the first end of the elastic energy storage mechanism is fixed on the first limb, a pulley is arranged on the joint head of the second limb, one end of the pull wire is fixed on the first limb, and the other end of the pull wire bypasses the pulley and is connected with the second end of the elastic energy storage mechanism.

6. The repositioning exoskeleton joint of claim 4 or claim 5, wherein: the device also comprises an adjusting device for adjusting the initial pretightening force of the elastic energy storage mechanism.

7. The repositioning exoskeleton joint of claim 4 or claim 5, wherein: and a limiting mechanism for limiting the rotation angle of the first limb is arranged between the first limb and the second limb.

8. The repositioning exoskeleton joint of claim 4 or claim 5, wherein: the tension spring or the pressure spring is a nonlinear spring.

9. An exoskeleton assistance device, comprising: the reduction exoskeleton joint as claimed in any one of claims 1 to 8, wherein the first limb is a thigh bone, the second limb is a shank bone, the lower end of the shank bone is connected with an elastic foot support, the upper end of the thigh bone is connected with the waist connecting rod through a joint bearing, and the reduction exoskeleton joint has three degrees of freedom in flexion, extension, lateral swing and rotation.