CN118927220A - Linear Actuators and Exoskeletons - Google Patents

Abstract

The present disclosure provides a linear actuator and an exoskeleton. The linear actuator includes: a cylinder body, a medium cavity filled with a magnetorheological medium is arranged in the cylinder body; a piston, which has a locked state restricted to the middle of the medium cavity and a moving state relative to the cylinder body; an air-filled portion, which is connected to the medium cavity and is configured to fill the inside of the medium cavity with a gas medium in response to the locked state of the piston to increase the pressure applied to the piston; and a magnetic portion, which is arranged in the medium cavity and has a power-on state and a power-off state; wherein, when the magnetic portion is in the power-on state, a magnetic field is formed to make the magnetorheological medium form a Bingham fluid to keep the piston in the locked state, and when the magnetic portion is in the power-off state, the piston is subjected to the pressure applied by the magnetorheological medium and/or the gas medium, so that the piston moves to the side away from the cylinder body. The exoskeleton includes a first portion, a second portion and a linear actuator.

Description

Linear actuating mechanism and exoskeleton

Technical Field

At least one embodiment of the present disclosure relates to a wearable device, and more particularly, to a linear actuator and exoskeleton.

Background

The exoskeleton is adapted to be worn on a person to provide additional force to the user to support, protect, or enhance the load carrying capacity of the user. Based on the difference in wearing positions of the exoskeletons, it can be classified into an upper limb exoskeletons, a waist exoskeletons, and a lower limb exoskeletons.

Because the exoskeleton is worn on the human body, a coupling relationship with the human body needs to be established. Taking the lower limb exoskeleton as an example, the first part of the lower limb exoskeleton needs to be adapted to the thigh (including hip joint) position, the second part of the lower limb exoskeleton needs to be adapted to the calf position, the knee joint part needs to be adapted to the knee position, and in a wearing state, the knee joint part needs to meet the flexion and extension actions of the thigh and the calf. At present, the knee joint part of the lower limb exoskeleton is mostly composed of a motor and a speed reducer with a large reduction ratio, and the working principle of the knee joint part is that the motor is used for providing power, and the motor is used for reducing speed and enhancing torque, so that the large torque acts on the exoskeleton (such as a first part and a second part).

In response to the flexion and extension movements of the user, the lower limb exoskeleton is generally provided with a speed reducer with a large reduction ratio, but the structure can cause poor reverse driving performance of the knee joint part; in addition, the knee joint part mainly depends on motor driving, and a large-capacity battery or a wire-drawing power supply is required to be configured, so that the operation time length or the application range of the exoskeleton can be limited; further, when the user's knee is subjected to a large load (e.g., the user jumps down from a high place), the knee portion of the exoskeleton does not have impact resistance, and thus, stability of the exoskeleton is caused.

Disclosure of Invention

To solve at least one of the above and other problems in the prior art, the present disclosure provides a linear actuator and an exoskeleton, in which a magnetic portion maintains a piston in a locked state stationary with respect to a cylinder in an energized state, and an air charging portion is adapted to inject a gaseous medium into a medium chamber in the locked state to provide a greater pressure to the piston when the piston is changed from the locked state to a moving state, thereby providing damping in a direction opposite to a pressure applied to the piston from the outside.

Embodiments of the present disclosure provide a linear actuator comprising: a cylinder body, wherein a medium cavity filled with magnetorheological medium is arranged in the cylinder body; a piston having a locked state restricted to a middle portion of the medium chamber and a moving state moving relative to the cylinder; an air charging portion, which is communicated with the medium cavity and is configured to charge a gas medium into the medium cavity in response to the locking state of the piston so as to increase the pressure applied to the piston; the magnetic part is arranged in the medium cavity and is provided with an electrified state and a powered-off state; wherein the magnetic part is in the energized state to form a magnetic field so that the magnetorheological medium forms a bingham fluid to hold the piston in the locked state, and the magnetic part is in the de-energized state to move the piston to a side away from the cylinder by pressure applied by the magnetorheological medium and/or the gaseous medium.

According to an embodiment of the present disclosure, the piston includes: the piston body is movably arranged in the medium cavity and divides the medium cavities at two axial sides of the piston body into two communicated subchambers; and a piston rod mounted on the piston body and configured to move with the piston body between an extended position away from the cylinder and a retracted position closer to the body.

According to an embodiment of the present disclosure, the magnetic portion is mounted on the piston body and is configured to move with the piston body.

According to an embodiment of the present disclosure, the magnetic portion is provided on a circumferential outer side of the piston body, and is configured to form a magnetic field along both axial ends of the medium chamber in the energized state.

According to an embodiment of the present disclosure, a medium flow passage for accommodating the magnetorheological medium and/or the gaseous medium is provided in the piston body; the piston also comprises a flow limiting plate which is pivotally arranged in the medium flow passage, and a flow limiting hole with the diameter smaller than the inner diameter of the medium flow passage is arranged in the flow limiting plate; wherein the flow restrictor plate is responsive to the state of the magnetic portion and is configured to oscillate between a blocking position in which the flow restrictor plate is attracted by the magnetic portion to overlie the media flow path and an open position in which the flow restrictor plate is at least partially displaced from the media flow path to regulate the flow rate of the magnetorheological medium therethrough.

According to the embodiment of the disclosure, an air injection channel for accommodating the air medium to pass through and be filled in the medium cavity is arranged in the piston rod.

According to an embodiment of the present disclosure, the gas charging portion includes a check valve provided between the gas injection passage and the medium chamber, and is configured to allow the gas medium to enter the medium chamber through the gas injection passage and to restrict the gas medium from overflowing from the medium chamber.

According to an embodiment of the present disclosure, the gas injection passage is provided in an axial direction of the piston rod, and an end portion located in the medium chamber is configured to communicate with the medium chamber; the gas charging part also comprises a gas charging rod which is telescopically arranged in the gas charging channel, so that the position of the gas charging rod of the gas medium is pressed into the gas charging channel.

According to an embodiment of the disclosure, the linear actuator further comprises a pressure release valve arranged on the cylinder body and adapted to discharge at least a part of the gaseous medium in the medium chamber.

Embodiments of the present disclosure also provide an exoskeleton comprising: a skeletal mechanism comprising: a first portion adapted to be worn on a thigh of a human body; a second portion adapted to be worn on a lower leg of a human body and pivotally connected to the first portion, the first portion and a connection location of the first portion being coupled to an outer side of a knee joint between the thigh and the lower leg; and the linear actuator is pivotally installed between the first part and the second part; the piston of the linear actuator is adapted to apply a pressure to the first and/or second portions, which is far away from each other, when the piston is changed from a locked state to a moving state, so as to damp approaching movements of the far-away ends of the first and second portions.

According to the linear actuating mechanism and the exoskeleton, the magnetorheological medium in the medium cavity is matched with the magnetic part, so that the piston has a locking state and a moving state in response to the state of the magnetic part. When the magnetic part is in a power-off state, the piston can move relative to the cylinder body, so that the outlet and return actions of the piston are not limited; when the magnetic part is in an electrified state, the piston is limited in the middle of the medium cavity, the air charging part is suitable for injecting a gas medium into the medium cavity in a locking state so as to provide larger pressure for the piston when the piston is changed from the locking state to a moving state, so that damping in the opposite direction to the pressure applied to the piston by the outside is formed, and buffering of the pressure applied to the outside is realized; furthermore, as the linear actuating mechanism only needs to supply power in the electrified state of the magnetic part, the load required by the linear actuating mechanism is smaller, and the use requirement can be met by configuring a battery with smaller capacity, so that the use scene of the linear actuating mechanism is facilitated to be expanded.

Drawings

FIG. 1 is a cross-sectional view of a linear actuator according to an illustrative embodiment of the present disclosure;

FIG. 2 is a perspective view of the piston core portion of the illustrative embodiment shown in FIG. 1; and

Fig. 3 is an enlarged view of a portion of the puffer stem of the illustrative embodiment shown in fig. 1. In the drawings, the reference numerals have the following meanings:

1. A cylinder;

11. A pressure release valve;

12. A bottom plate;

13. An outer sleeve of the cylinder body;

2. a magnetic section;

21. A metal ring;

22. A coil;

23. Externally connecting a wire;

3. A guide part;

31. A limiting block;

32. A guide upper end cap;

33. A guide;

34. A guide lower end cap;

4. An inflation part;

41. A gas compressing rod;

411. An air inlet groove;

412. A limit groove;

413. a seal ring;

42. An outer sleeve of the inflator;

5. A piston;

51. A piston rod;

52. a piston lower end cap;

53. A piston valve core;

54. A pin;

55. a piston upper end cap;

56. a piston outer cylinder;

57. a media flow path;

58. a flow-limiting plate; and

59. A pivoting member.

Detailed Description

For the purposes of promoting an understanding of the principles and advantages of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms, including technical and scientific terms, used herein have the meaning commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

Where a formulation similar to at least one of "A, B and C, etc." is used, such as "a system having at least one of A, B and C" shall be interpreted in the sense one having ordinary skill in the art would understand the formulation generally, for example, including but not limited to systems having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc. Where a formulation similar to at least one of "A, B or C, etc." is used, such as "a system having at least one of A, B or C" shall be interpreted in the sense one having ordinary skill in the art would understand the formulation generally, for example, including but not limited to systems having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.

Fig. 1 is a cross-sectional view of a linear actuator according to an illustrative embodiment of the present disclosure.

According to the linear actuator provided by the present disclosure, as shown in fig. 1, the linear actuator includes a cylinder 1, a piston 5, an inflating portion 4, and a magnetic portion 2. A medium cavity filled with magnetorheological medium is arranged in the cylinder body 1. The piston 5 has a locked state, which is limited to the middle of the medium chamber, and a moving state, which moves relative to the cylinder 1. The gas charging portion 4 communicates with the medium chamber and is configured to charge the inside of the medium chamber with a gaseous medium in response to the locked state of the piston 5 to increase the pressure applied to the piston 5. The magnetic part 2 is provided in the medium chamber and has an energized state and a de-energized state. The magnetic part 2 is in an energized state to form a magnetic field so that the magnetorheological medium forms a bingham fluid to hold the piston 5 in a locked state, and in a de-energized state, the piston 5 receives pressure applied by the magnetorheological medium and/or the gas medium to move the piston 5 to a side away from the cylinder 1.

In an exemplary embodiment, as shown in fig. 1, the cylinder 1 includes a cylinder outer sleeve 13 and a bottom plate 12. In detail, the cylinder outer sleeve 13 is constructed in a hollow cylindrical structure, and one end (an upper end as shown in fig. 1) of the cylinder outer sleeve 13 is mounted with the bottom plate 12.

In an exemplary embodiment, as shown in fig. 1, the linear actuator further comprises a guide 3. In detail, the guide portion 3 includes a guide 33 mounted to the other end (lower end as shown in fig. 1) of the cylinder outer sleeve 13 to accommodate the piston rod 51 of the piston 5 protruding from the cylinder 1 and to make the extending direction of the axis of the piston 5 coincide with the extending direction of the axis of the cylinder 1. Wherein the interior of the cylinder outer sleeve 13 between the guide 33 and the bottom plate 12 defines a medium chamber.

In an exemplary embodiment, the guide 3 also includes a guide upper end cap 32 and a guide lower end cap 34 as shown in FIG. 1. Specifically, the guide upper end cover 32 and the guide lower end cover 34 are provided on both sides of the guide 33 in the axial direction. Further, the upper end cap 32 and the lower end cap 34 are respectively fixed on the outer sleeve 13 via at least one limiting block 31 to limit the position of the guide 33 relative to the outer sleeve 13 to seal the medium chamber.

In an exemplary embodiment, the gaseous medium includes, but is not limited to, air or compressed air, such that the air charged into the medium chamber may pass through a magnetorheological medium under the influence of the charging portion to increase the pressure within the medium chamber, including, but not limited to, using a magnetorheological fluid (MRF). In this way, in the magnetic field formed by the magnetic part, the magnetorheological medium can be converted into a high-viscosity low-fluidity bingham fluid, so that the position of the piston 5 relative to the cylinder 1 is limited, and the medium cavity can be inflated; when the magnetic field formed by the magnetic part disappears (namely the magnetic part is powered off), the magnetorheological medium can restore the fluid form, so that the piston moves more rapidly under the action of the air pressure provided by the air medium and outputting more pressure. Further, magnetorheological fluid (MRF) relies on the applied magnetic field strength to form a bingham fluid that is adapted to the magnetic field strength (e.g., the magnetorheological fluid may be in a higher viscosity but still flowable fluid form when the applied voltage to the magnetic portion is low, resulting in a lower magnetic field strength), such that the magnetorheological fluid may provide damping to the movement of the piston when the magnetic field is applied but still flowable fluid form.

In such an embodiment, the magnetorheological medium in the medium chamber and the magnetic portion cooperate to provide the piston with a locked state and a displaced state in response to the state of the magnetic portion. When the magnetic part is in a power-off state, the piston can move relative to the cylinder body, so that the outlet and return actions of the piston are not limited; when the magnetic part is in an electrified state, the piston is limited in the middle of the medium cavity, the air charging part is suitable for injecting a gas medium into the medium cavity in a locking state so as to provide larger pressure for the piston when the piston is changed from the locking state to a moving state, so that damping in the opposite direction to the pressure applied to the piston by the outside is formed, and buffering of the pressure applied to the outside is realized; furthermore, as the linear actuating mechanism only needs to supply power in the electrified state of the magnetic part, the load required by the linear actuating mechanism is smaller, and the use requirement can be met by configuring a battery with smaller capacity, so that the use scene of the linear actuating mechanism is facilitated to be expanded.

According to an embodiment of the present disclosure, as shown in fig. 1, the linear actuator further comprises a pressure relief valve 11 provided on the cylinder 1, adapted to discharge at least a portion of the gaseous medium in the medium chamber.

In an exemplary embodiment, as shown in FIG. 1, a pressure relief valve 11 is provided in the middle of the base plate 12. Further, the linear actuator is configured such that the piston 5 is disposed downward. In this way, when the medium cavity is filled with the gaseous medium, the bubbles formed by the gaseous medium can suspend at the upper part of the medium cavity, which is beneficial to discharging the gaseous medium through the pressure release valve.

According to an embodiment of the present disclosure, as shown in fig. 1, the piston 5 includes a piston body and a piston rod 51. The piston body is movably arranged in the medium cavity and divides the medium cavity at two sides of the axial direction of the piston body into two communicated subchambers. The piston rod 51 is mounted on the piston body and is configured to move with the piston body between an extended position remote from the cylinder 1 and a retracted position close to the body.

In one illustrative embodiment, as shown in FIG. 1, the piston body includes a piston outer barrel 56 provided with an opening. In detail, the opening provided by the piston outer cylinder 56 is provided facing the bottom plate 12 (upward as shown in fig. 1) of the cylinder 1.

In one exemplary embodiment, as shown in fig. 1, the piston body further includes a piston lower end cap 52, a piston upper end cap 55, and a piston spool 53 disposed within the opening of the piston outer barrel 56. Specifically, the piston lower end cap 52 is provided at the lower portion of the opening of the piston outer tube 56, the piston upper end cap 55 is provided at the upper portion of the opening of the piston outer tube 56, and the piston valve body 53 is fixed between the piston lower end cap 52 and the piston upper end cap 55 by the pin 54 so as to be restrained within the piston outer tube 56.

In one illustrative embodiment, as shown in FIG. 1, the piston body divides the medium chamber on either side of the piston spool 53 in the axial direction into a first subchamber (a cylindrical portion of the medium chamber above the piston spool 53 as shown in FIG. 1) and a second subchamber (an annular portion of the medium chamber between the piston outer cylinder 56 and the piston lower end cap 52 below the piston spool 53 as shown in FIG. 1).

In one illustrative embodiment, as shown in FIG. 1, a piston lower end cap 52, a piston valve core 53, and a piston upper end cap 55 collectively form a through media flow path. In detail, the piston valve core 53 serves as a main body of the medium flow passage, and openings are provided in the piston lower end cover 52 and the piston upper end cover 55 at positions facing the main body of the medium flow passage, respectively, and are an input port and an output port for the piston to travel and return.

In an exemplary embodiment, as shown in fig. 1, the opening provided in the piston upper end cap 55 is configured to extend in the axial direction of the piston (up-down direction as shown in fig. 1), the opening provided in the piston lower end cap 52 is configured to be L-shaped, the portion facing the piston spool 53 (upper portion as shown in fig. 1) is configured to extend in the axial direction of the piston (up-down direction as shown in fig. 1), and the portion distant from the piston spool 53 (lower portion as shown in fig. 1) is configured to extend in the radial direction of the piston (left-right direction as shown in fig. 1) to communicate the first sub-chamber and the second sub-chamber.

According to an embodiment of the present disclosure, as shown in fig. 1, a magnetic portion 2 is mounted on a piston body and is configured to move with the piston body.

According to the embodiment of the present disclosure, as shown in fig. 1, the magnetic portion 2 is provided on the circumferential outside of the piston body, and is configured to form a magnetic field along both axial ends of the medium chamber in the energized state.

In an exemplary embodiment, as shown in fig. 1, the magnetic part 2 includes a metal ring 21 (e.g., copper alloy ring, aluminum alloy ring), a coil 22, and an external lead 23. Specifically, the metal ring 21 is provided between the piston upper end cap 55 and the piston lower end cap 52, and covers the outside of the piston valve body 53. The coil 22 is provided outside the metal ring 21 to form magnetic poles (including N and S poles) extending in the axial direction of the piston (up-down direction as shown in fig. 1) in the energized state. Further, one end of the external lead 23 is connected to the coil, and the other end is configured to be led out from the cylinder 1 to be connected to an external circuit to control the on or off of the coil.

In such an embodiment, the magnetic portion is configured to form a magnetic pole along the extending direction of the piston, and in the energized state, the medium chambers (i.e., the first subchamber and the second subchamber) located on both sides of the piston (upper side and lower side as shown in fig. 1) are both located within the magnetic field of the magnetic portion to form a guest-han fluid under the influence of the magnetic field, thereby clamping the piston to limit the position of the piston relative to the cylinder.

Fig. 2 is a perspective view of the piston core portion of the illustrative embodiment shown in fig. 1.

According to an embodiment of the present disclosure, as shown in fig. 1 and 2, a medium flow passage 57 accommodating passage of a magnetorheological medium and/or a gaseous medium is provided in the piston body. The piston 5 further includes a restrictor plate 58 pivotally mounted within the media flow path 57, the restrictor plate 58 being responsive to the state of the magnetic portion 2 and configured to oscillate between a blocking position in which the restrictor plate 58 overlies the media flow path 57 and an open position at least partially displaced from the media flow path 57 to regulate the flow of magnetorheological media therethrough.

In one illustrative embodiment, as shown in FIG. 2, the piston upper end cap 55 and/or the piston lower end cap 52 are configured to form a gap with the piston spool 53 in the axial extension direction of the piston (up-down direction as shown in FIG. 1). Further, an axial end (a lower end as viewed in fig. 1) of the piston spool 53 near the piston lower end cap 52 is configured to be pivotally mounted with a restrictor plate 58 by a pivot member 59.

In one illustrative embodiment, as shown in FIG. 2, the restrictor plate 58 is configured as an annular (or ring-like) sheet-like structure. In detail, the restrictor plate 58 includes, but is not limited to, a material configured to be attracted to a magnetic material (e.g., a metal material or an alloy material including iron, cobalt, and nickel).

In such an embodiment, the restrictor plate 58 is configured to be subjected to attractive forces extending in the axial direction of the piston (up-down direction as viewed in fig. 2) to overlie the media flow path 57 when the magnetic portion is energized, and the magnetorheological medium and the gaseous medium are configured to pass from the first subchamber through the media flow path into the second subchamber when the magnetic portion is de-energized, the restrictor plate 58 being turned downward by the magnetorheological medium to enlarge the cross-sectional area defined by the media flow path and the apertures provided in the restrictor plate 58 to increase the flow rate of the magnetorheological medium and/or the gaseous medium to allow the magnetorheological medium to pass through the media flow path rapidly.

According to an embodiment of the present disclosure, as shown in fig. 1 and 3, the inside of the piston rod 51 is provided with a gas injection passage that accommodates a gaseous medium therethrough and fills the medium chamber.

According to an embodiment of the present disclosure, as shown in fig. 1, the gas charging portion 4 includes a check valve 43 disposed between the gas injection passage and the medium chamber, and is configured to allow the gaseous medium to enter the medium chamber from the gas injection passage and to restrict the gaseous medium from overflowing from the medium chamber.

According to an embodiment of the present disclosure, as shown in fig. 1, the gas injection passage is provided in the axial direction of the piston rod 51, and the end portion located in the medium chamber is configured to communicate with the medium chamber. The charging section 4 further includes a gas lever 41 telescopically mounted in the gas injection passage so that the position of the gas medium gas lever 41 is pressed into the gas injection passage.

In an exemplary embodiment, as shown in FIG. 1, the piston rod 51 is configured as a hollow structure, and further, the piston 51 is internally provided with a cylinder outer sleeve 42 defining a gas injection passage therein.

In an exemplary embodiment, as shown in fig. 1, the intake side of the gas injection passage is provided at the end of the piston rod 51 (the lower end as shown in fig. 1) that protrudes from the cylinder 1. Further, the gas outlet side of the gas injection passage is provided on one side (left side as shown in fig. 1) of the piston rod 51 in the radial direction within the cylinder 1.

In an exemplary embodiment, as shown in FIG. 1, a one-way valve 43 is mounted between the outlet side of the gas injection channel and the piston rod 51. In detail, the check valve 43 is configured to allow the gaseous medium to pass from the side of the gas injection passage (right side as shown in fig. 1) and enter the side of the medium chamber (left side as shown in fig. 1).

Fig. 3 is an enlarged view of a portion of the puffer stem of the illustrative embodiment shown in fig. 1.

In an exemplary embodiment, as shown in fig. 3, the end portion (the lower end portion as shown in the drawing) of the air compressing rod 41 located in the air injecting channel is provided with two flanges (i.e., a first flange and a second flange as shown in fig. 3) protruding outwards at intervals along the axial direction of the air compressing rod 41, a sealing ring 413 is sleeved on the outer side of the air compressing rod 41 between the two flanges, and the sealing ring is limited in a limiting groove 412 arranged along the circumferential direction of the air compressing rod 41 and is configured to be movable along the axial direction (up-down direction as shown in fig. 3) of the air compressing rod 41. In detail, the outer diameter of the first flange near the inlet side (upper side as shown in fig. 3) of the gas injection channel is configured to be substantially the same as the inner diameter of the gas injection channel to abut against the inner wall of the gas injection channel, and the outer diameter of the second flange near the outlet side (lower side as shown in fig. 3) of the gas injection channel is configured to be smaller than the inner diameter of the gas injection channel. Further, the outer diameter of the compression rod between the first flange and the second flange is smaller than the inner diameter of the sealing ring 413.

In an exemplary embodiment, as shown in fig. 3, the outer edge of the first flange is provided with at least one air inlet slot 411 extending axially therethrough. Further, the axial position of the sealing ring 413 coincides with the orthographic projection of the air inlet slot 411 along the axial direction (up-down direction as shown in fig. 3) of the air compressing rod 41, so as to seal the air inlet slot 411 in a state that the sealing ring 413 abuts against the first flange, so that a sealed air injecting cavity is formed between the sealing member 411 and the air outlet side of the air injecting channel.

In such an embodiment, during the reciprocating movement of the gas lever along the gas injection channel (up and down as shown in fig. 3), the sealing member is displaced along with the gas cylinder to press the gaseous medium into the gas injection channel and eventually into the medium chamber (e.g., when the gas lever is up, the sealing ring is positioned at the lower portion as shown in fig. 3 to accommodate the gas entering the lower portion of the second flange through the gas inlet slot, and when the gas lever is down, the sealing ring is positioned at the upper portion as shown in fig. 3 to seal the gas inlet slot 411, so that the gaseous medium in the sealed gas injection chamber is pressed into the medium chamber).

According to the exoskeleton provided by the present disclosure, not shown in the drawings, the exoskeleton comprises a skeleton mechanism and a linear actuator. The bone mechanism includes a first portion and a second portion. The first portion is adapted to be worn on a thigh of a human body. The second portion is adapted to be worn on a calf of a person and is pivotally connected to the first portion, the connection location of the first portion and the first portion being coupled to the outside of the knee joint between the thigh and the calf. The linear actuator is pivotally mounted between the first and second portions. The piston 5 of the linear actuator is adapted to apply a pressure to the first and/or second portion away from each other in a state of movement from the locked state to the moved state, so as to damp the approaching movement of the distal ends of the first and second portions.

In an exemplary embodiment, the first and second portions include, but are not limited to being configured as a full-coverage or half-coverage type. Further, the linear actuator is disposed on one side of the first portion and the second portion (e.g., on the outer side of the lower limb), so as not to block the first portion and the second portion from being closed and expanded, and the exoskeleton is preferably adapted to the buckling and straightening actions of the lower limb.

In such an embodiment, the exoskeleton is worn on the lower limb of the user, and when the user determines that the lower limb needs to bear a large force according to the use situation (such as the user needs to jump down from a high place, etc.), a proper buckling range can be selected first, so that the piston is positioned in the middle of the cylinder body; then, the magnetic part is in an electrified state so as to maintain the buckling amplitude and the inflation part is used for inflating; after the inflation is completed, the magnetic field intensity of the magnetic part (such as voltage value reduction) can be reduced or the magnetic part is in a power-off state, so that the piston moves out of the way to overcome the pressure of the outside on the lower limb of the user, and the user is buffered; after the action is completed, a user can open the pressure release valve to enable the gas in the medium cavity to be used next time.

In such an embodiment, in the de-energized state of the magnetic portion of the linear actuator, both the user's buckling and straightening actions are not impeded; in addition, as the linear actuating mechanism only needs to carry out short-term power supply when forming an electromagnetic field, compared with the existing exoskeleton with main power supply driven by a motor, the requirement on power supply is obviously reduced, and a large-capacity battery or a wire-drawing power supply is not required to be configured, so that the use scene of the exoskeleton is favorably expanded; further, the linear actuator provides a greater pressure to the piston in the energized state of the magnetic portion to provide damping in a direction opposite to the externally applied pressure to achieve cushioning when the piston is released, thereby protecting the user and improving the stability of exoskeleton use.

It should be further noted that, the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only referring to the directions of the drawings, and are not intended to limit the scope of the present disclosure. Like elements are denoted by like or similar reference numerals throughout the drawings. Conventional structures or constructions will be omitted when they may cause confusion in understanding the present disclosure.

The embodiments of the present disclosure are described above. These examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the embodiments cannot be used advantageously in combination. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be made by those skilled in the art without departing from the scope of the disclosure, and such alternatives and modifications are intended to fall within the scope of the disclosure.

Claims (10)

1. A linear actuator, comprising:

The device comprises a cylinder body (1), wherein a medium cavity filled with magnetorheological medium is arranged in the cylinder body (1);

A piston (5) having a locked state restricted to a middle portion of the medium chamber and a moving state moving relative to the cylinder (1);

an air charging portion (4) communicating with the medium chamber and configured to charge an inside of the medium chamber with a gaseous medium in response to a locked state of the piston (5) to increase a pressure applied to the piston (5); and

A magnetic part (2) which is arranged in the medium cavity and has an electrified state and a powered-off state;

Wherein the magnetic part (2) is in the energized state to form a magnetic field so as to enable the magnetorheological medium to form a bingham fluid to keep the piston (5) in the locking state, the magnetic part (2) is in the power-off state, and the piston (5) is subjected to pressure exerted by the magnetorheological medium and/or the gas medium to enable the piston (5) to move to the far side relative to the cylinder body (1).

2. Actuator according to claim 1, wherein the piston (5) comprises:

The piston body is movably arranged in the medium cavity and divides the medium cavities at two axial sides of the piston body into two communicated subchambers; and

A piston rod (51) mounted on the piston body and configured to move with the piston body between an extended position remote from the cylinder (1) and a retracted position close to the body.

3. The actuator according to claim 2, wherein the magnetic part (2) is mounted on the piston body and is configured to move with the piston body.

4. An actuator according to claim 3, wherein the magnetic portion (2) is provided on the circumferential outer side of the piston body and is configured to form a magnetic field along both axial ends of the medium chamber in the energized state.

5. Actuator according to claim 2, wherein a medium flow channel (57) is provided in the piston body for receiving the magnetorheological medium and/or the gaseous medium therethrough;

the piston (5) further comprises a flow limiting plate (58) which is pivotally arranged in the medium flow channel (57), and a flow limiting hole with the diameter smaller than the inner diameter of the medium flow channel (57) is arranged in the flow limiting plate (58);

Wherein the restrictor plate (58) is responsive to the state of the magnetic portion (2) and is configured to oscillate between a blocking position in which it is attracted by the magnetic portion (2) such that the restrictor plate (58) overlies the media flow path (57), and an open position in which it is at least partially displaced from the media flow path (57) to regulate the flow rate of the magnetorheological medium therethrough.

6. Actuator according to claim 2, wherein the piston rod (51) is internally provided with a gas injection channel for receiving the gaseous medium therethrough and filling the medium chamber.

7. The actuator of claim 6, wherein the plenum (4) includes a one-way valve (43) disposed between the gas injection passage and the medium chamber, configured to allow the gaseous medium to enter the medium chamber from the gas injection passage and to restrict the gaseous medium from escaping from the medium chamber.

8. Actuator according to claim 6, wherein the gas injection channel is arranged in the axial direction of the piston rod (51), the end located in the medium chamber being configured to communicate with the medium chamber;

The inflating part (4) further comprises a gas pressing rod (41) which is telescopically arranged in the gas injection channel, so that the position of the gas pressing rod (41) of the gas medium is pressed into the gas injection channel.

9. Actuator according to any of claims 1-8, further comprising a pressure relief valve (11) arranged on the cylinder (1) adapted to displace at least a part of the gaseous medium in the medium chamber.

10. An exoskeleton, which is made of a plastic, is provided, characterized by comprising the following steps:

A skeletal mechanism comprising:

a first portion adapted to be worn on a thigh of a human body;

A second portion adapted to be worn on a calf of a human body and pivotally connected to the first portion, the first portion and a connection location of the first portion being coupled to an outside of a knee joint between the thigh and the calf; and

The linear actuator of any one of claims 1 to 9, pivotally mounted between the first and second portions;

Wherein the piston (5) of the linear actuator is adapted to apply a pressure to the first and/or second part away from each other to apply a pressure to the first part and IB232233 when the piston is changed from a locked state to a moving state

The approaching action of the distant ends of the second portion forms a damping.