CN116922421A - Space multistable mechanism - Google Patents

Abstract

The invention discloses a space multistable mechanism, which relates to the field of flexible mechanisms, solves the problem of short service life of the existing multistable mechanism, facilitates the switching of stable positions in space, and expands the application scene, and the specific scheme is as follows: the initial state of the flexible bistable mechanism is in a dome shape, a rotor is arranged at the central position of the flexible bistable mechanism and is fixedly connected with the end part of the flexible actuating mechanism, the flexible actuating mechanism is composed of an end effector and flexible beam groups symmetrically and fixedly arranged at two sides of the end effector, and the flexible bistable mechanism vertically displaces when the end effector makes linear motion along the axis direction perpendicular to the flexible actuating mechanism so as to provide force for deflecting the end effector from an initial balance position to a buckling position and resist the reactive force of deformation of the flexible actuating mechanism.

Description

A spatial multistable mechanism

Technical field

The invention relates to the technical field of flexible mechanisms, and in particular to a spatial multi-stable mechanism.

Background technique

Multistable mechanisms with multiple stable positions are commonly used in adaptive systems and other fields. Traditional adaptive systems apply external force or friction to keep the system in the required stable position. Systems that apply external force require a large amount of energy, and systems that use friction will cause losses, which will reduce the efficiency of the system and may eventually lead to system failure. . Therefore, there is a need to replace the traditional mechanism with a mechanism that can remain in one or more stable positions without relying on external force or friction.

Most of the existing multi-stable mechanisms that do not rely on external forces use straight beam bistable mechanisms (such as Publication No. CN101837947A, CN101798052A). The length of the straight beam is limited, the load resistance to external forces is limited, and it cannot be used when large buckling occurs. Uniform distribution of stress during deformation leads to short service life; in addition, existing multi-stable mechanisms are mostly limited to a plane and cannot achieve stable switching in space.

Contents of the invention

In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a spatial multi-stable mechanism, which is provided with a dome-shaped flexible bi-stable mechanism and expands the length of the flexible bi-stable mechanism beam at the same end point. , can better resist external loads, have a more uniform stress distribution when large buckling deformation occurs, increase the fatigue life of the flexible bistable mechanism, and solve the problem of short service life of the existing multi-stable mechanism.

In order to achieve the above objects, the present invention is achieved through the following technical solutions:

The invention provides a spatial multi-stable mechanism, which includes a vertically arranged flexible actuator. At least one end of the flexible actuator is connected in series with a flexible bistable mechanism. Both ends of the flexible bistable mechanism are respectively fixed with a fixed end, the initial state of the flexible bistable mechanism is a dome shape, a mover is provided at the center of the flexible bistable mechanism and is fixedly connected to the end of the flexible actuator, the flexible actuator is composed of an end effector And the flexible beam assembly is symmetrically fixed and installed on both sides of the end effector. The flexible bistable mechanism vertically displaces when the end effector moves linearly in the direction perpendicular to the axis of the flexible actuator to provide the end effector with a vertical displacement. The reaction force that deflects a flexible actuator from its initial equilibrium position to a buckled position and resists deformation of a flexible actuator.

As a further implementation, the flexible bistable mechanism is bent toward the flexible actuator. The flexible bistable mechanism is composed of two sets of first flexible beams, and the two sets of first flexible beams are symmetrically arranged on both sides of the first mover and Adjacent ends of the two sets of first flexible beams are fixedly connected together through the first mover.

As a further implementation method, each set of first flexible beams is composed of two circular arch-shaped first flexible beams arranged in parallel up and down, and a first rigid beam is fixed at the middle position of each first flexible beam.

As a further implementation, the first flexible beam and the first rigid beam have the same circle center.

As a further implementation, the flexible actuator has a square cross-section.

As a further implementation, each group of flexible beams is vertically enclosed by four second flexible beams with a square cross-section, and the adjacent ends of the four second flexible beams in the same group are fixed by second rigid beams. connected together.

As a further implementation, the fixed end is provided with bolt holes for bolt fixing.

As a further implementation, the end effector has a square cross-section, and the end effector is not stressed in the initial state.

As a further implementation, the cross-sectional area of the end effector is the same as the cross-sectional area of the flexible beam set.

As a further implementation, two adjacent fixed ends are arranged symmetrically along the center line of the flexible actuator.

The above-mentioned beneficial effects of the present invention are as follows:

(1) The present invention is equipped with a dome-shaped flexible bistable mechanism, which expands the length of the flexible bistable mechanism beam at the same end point, can better resist external loads, and can have a flexible structure when large buckling deformation occurs. More uniform stress distribution increases the fatigue life of the flexible bistable mechanism; at the same time, the flexible actuator is a symmetrical structure with spatial symmetry, which makes it have higher stability when moving in space. With the use of a fixed end, the flexible actuator During the process of switching steady-state positions, the flexible bistable mechanism does not have to pass through the initial position, which reduces unnecessary motion behaviors and improves the life of the spatial multi-stable mechanism.

(2) The flexible bistable mechanism of the present invention is a device that stores deformation energy. By means of its deformation energy storage mover, the mover can achieve stable balance at multiple independent positions without the need to apply external force to make the mover stay.

(3) The first flexible beam and the first rigid beam of the present invention have the same circle center, which can enhance the stability of a single flexible limb to ensure accurate switching of stable states, and will not cause interference during each stable state conversion process. The circular arch structure has better resistance to out-of-plane deformation than the straight beam structure, allowing the steady-state motion in different directions to maintain better consistency.

(4) The flexible beam group of the present invention is vertically enclosed by four second flexible beams with a square cross-section, and the cross-sectional area of the end effector is the same as that of the flexible beam group. It has spatial symmetry and can be used in Steady-state position switching is performed in space, with a variety of switching methods and control methods, which broadens the application fields and control scenarios of multi-stable mechanisms.

Description of the drawings

The description and drawings that constitute a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

Figure 1 is a schematic structural diagram of the first stable state (initial processing and assembly state) of the spatial multi-stable mechanism in Embodiment 1 of the present invention;

Figure 2 is a schematic structural diagram of the second stable state of the spatial multi-stable mechanism in Embodiment 1 of the present invention;

Figure 3 is a schematic structural diagram of the third stable state of the spatial multi-stable mechanism in Embodiment 1 of the present invention;

Figure 4 is a schematic structural diagram of the fourth stable state of the spatial multi-stable mechanism in Embodiment 1 of the present invention;

Figure 5 is a schematic structural diagram of the fourth stable state of the spatial multi-stable mechanism in Embodiment 1 of the present invention from another perspective;

Figure 6 is a schematic structural diagram of the fifth stable state of the spatial multi-stable mechanism in Embodiment 1 of the present invention;

Figure 7 is a schematic structural diagram of the first stable state of the spatial multi-stable mechanism in Embodiment 2 of the present invention;

Figure 8 is a schematic structural diagram of the second stable state of the spatial multi-stable mechanism in Embodiment 2 of the present invention;

Figure 9 is a schematic structural diagram of the third stable state of the spatial multi-stable mechanism in Embodiment 2 of the present invention;

Figure 10 is a schematic structural diagram of the fourth stable state of the spatial multi-stable mechanism in Embodiment 2 of the present invention;

Figure 11 is a schematic structural diagram of the fourth stable state of the spatial multi-stable mechanism in Embodiment 2 of the present invention from another perspective;

Figure 12 is a schematic structural diagram of the fifth stable state of the spatial multi-stable mechanism in Embodiment 2 of the present invention;

In the figure: the distance or size between each part is exaggerated to show the position of each part, and the schematic diagram is for illustrative purposes only;

Among them, 1. The first flexible bistable mechanism; 2. The flexible actuator; 3. The end effector; 4. The first fixed end; 5. The first mover; 6. The second mover; 7. The second flexible Bistable mechanism; 8. Second fixed end; 9. First flexible beam; 10. First rigid beam; 11. Second flexible beam; 12. Second rigid beam.

Detailed ways

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meanings commonly understood by one of ordinary skill in the art to which this invention belongs.

As introduced in the background technology, most of the existing multi-stable mechanisms that do not rely on external forces use straight beam bistable mechanisms. The length of the straight beam is limited, the load resistance to external forces is limited, and it cannot undergo large buckling deformation. The stress is uniformly distributed, resulting in a short service life; in addition, the existing multi-stable mechanisms are mostly limited to a plane and cannot realize the problem of stable switching in space. In order to solve the above technical problems, the present invention proposes a A spatial multistable mechanism.

Example 1

In a typical implementation of the present invention, as shown in Figures 1 to 6, a spatial multi-stable mechanism is proposed, including a first flexible bistable mechanism 1 and a flexible actuator 2. The bistable mechanism 1 is connected in series (fixedly installed) at one end of the flexible actuator 2. As shown in Figure 1, the first stable state is the initial state of the first flexible bistable mechanism 1. The first flexible state in the first stable state The bistable mechanism 1 is in the shape of a round arch, and the first flexible bistable mechanism 1 is bent toward the flexible actuator 2 .

A first fixed end 4 is fixedly installed at both ends of the first flexible bistable mechanism 1. The two first fixed ends 4 are symmetrically arranged along the center line of the flexible actuator 2. The first fixed end 4 is provided with bolt holes. , for bolting.

The first flexible bistable mechanism 1 is composed of two groups of first flexible beams 9 . Each group of first flexible beams 9 is composed of two dome-shaped first flexible beams 9 arranged in parallel up and down. The two groups of first flexible beams 9 The adjacent ends are fixedly connected together through the first mover 5. A first rigid beam 10 is fixed at the middle position of each first flexible beam 9. Two sets of first flexible beams 9 are symmetrically arranged on the first mover. 5 on both sides.

The first mover 5 is fixedly connected to one end of the flexible actuator 2. When the first mover 5 moves along the axial direction of the flexible actuator 2, the end effector 3 of the flexible actuator 2 can move along the direction perpendicular to the flexible actuator. The direction of the axis of the mechanism 2 makes a linear motion, and the first flexible bistable mechanism 1 is displaced in the direction of the flexible actuator 2 (that is, vertical displacement), providing a force to deflect the end effector 3 from the initial equilibrium position to the buckling position. , and resists the reaction force of the deformation of the flexible actuator 2, keeping the end effector 3 in a stable state.

The flexible actuator 2 is a columnar structure arranged vertically. The cross-section of the flexible actuator 2 is square. The flexible actuator 2 is a symmetrical structure with an end effector 3 in the middle. Two sets of flexible flexible actuators are symmetrically fixed on both sides of the end effector 3. beam group.

Specifically, the flexible actuator 2 is composed of two flexible beam groups and an end effector 3 with a square cross-section. Each flexible beam group is vertically arranged and enclosed into a column by four second flexible beams 11 with a square cross-section. space, the ends of the two flexible beam groups are fixedly connected together through an end effector 3, and the adjacent ends of the four second flexible beams 11 in the same group are fixedly connected together through the second rigid beam 12, and the end effector 3 The cross-sectional area of the device 3 is the same as the cross-sectional area of the flexible beam group.

The end effector 3 is located between the two sets of second flexible beams 11. As shown in Figure 1, in the first stable state, the end effector 3 in the flexible actuator 2 is not stressed and is naturally perpendicular to the two first fixed beams. Terminal 4.

Since the first flexible bistable mechanism 1 is a circular arch structure, at the same end point, the length of the circular arch beam is longer than that of the straight beam, which can better resist external loads and can be used when large buckling deformation occurs. More uniform stress distribution increases the fatigue life of the first flexible bistable mechanism 1 .

In this embodiment, the first flexible beam 9 and the first rigid beam 10 are integrally formed, and the second flexible beam 11 and the second rigid beam 12 are integrally formed. The first flexible beam 9 and the first rigid beam 10 have the same circle center. The stability of a single flexible limb can be enhanced to ensure accurate switching of stable states without interference during each steady state conversion process.

The spatial steady motion of the spatial multi-stable mechanism in this embodiment is specifically as follows, where the Z-axis direction is the direction in which the axis of the flexible actuator 2 faces the first flexible bi-stable mechanism 1 in the horizontal plane; the X-axis direction is the horizontal plane The inner direction is perpendicular to the axis of the flexible actuator 2 and to the right from the perspective of Figure 1; the Y-axis direction is the direction perpendicular to the paper surface and outward from the perspective of Figure 1:

As shown in Figure 2, the second stable state is that in the spatial coordinates, the end effector 3 of the flexible actuator 2 is displaced in the positive direction of the X-axis, causing the flexible actuator 2 to deflect to the right. The first flexible double Steady-state mechanism 1 displaces downward and reaches a stable state;

As shown in Figure 3, the third stable state is that in spatial coordinates, the end effector 3 of the flexible actuator 2 is displaced in the negative direction of the X-axis, causing the flexible actuator 2 to deflect to the left. The first flexible double Steady-state mechanism 1 displaces downward and reaches a stable state;

As shown in Figures 4 and 5, the fourth stable state is that in spatial coordinates, the end effector 3 of the flexible actuator 2 is subject to a displacement in the positive Y-axis direction, causing the flexible actuator 2 to deflect in the positive direction of the Y-axis. , the first flexible bistable mechanism 1 displaces downward and reaches a stable state;

As shown in Figure 6, the fifth stable state is that in spatial coordinates, the end effector 3 of the flexible actuator 2 is subject to a negative Y-axis displacement, causing the flexible actuator 2 to deflect in the negative Y-axis direction. The first The flexible bistable mechanism 1 displaces downward and reaches a stable state.

Since the multi-stable mechanism in this embodiment has a motion form in the spatial direction, the first flexible bi-stable mechanism 1-beam bi-stable mechanism has better resistance to out-of-plane deformation than the straight beam bi-stable mechanism, so that in different directions The steady-state motion maintains good consistency. In terms of motion: the multi-stable mechanism in this embodiment has the same number of stable equilibrium positions on the X-axis and the Y-axis, and is not limited to stable equilibrium positions in a two-dimensional plane, so that the multi-stable mechanism can accurately move On the premise of reaching each stable position, the direction of the stable position of the multi-stable mechanism is broadened.

The first flexible bistable mechanism 1 is a device that stores deformation energy. By means of its deformation energy storage mover, the mover can achieve stable balance at multiple independent positions without the need to apply external force to stop the mover.

Since the second flexible beam 11 of the flexible actuator 2 is symmetrically arranged and has spatial symmetry, it will have higher stability when moving in space, and when switching between two stable states, the first flexible bistable state Mechanism 1 will maintain the second steady-state position unchanged, and the flexible actuator does not need to pass through the initial position during the steady-state position switching process, and can directly enter the next steady-state position (as shown in Figure 2, the state switches to Figure 3). display state), reducing unnecessary motion behaviors and improving the life of the spatial multi-stable mechanism; and allowing the multi-stable mechanism to have a variety of switching methods and control methods when used in fields such as switches, broadening the scope of multi-stable mechanisms. application areas and control scenarios of dynamic mechanisms.

Since the first flexible bistable mechanism will not change its stable position during the switching process between the two stable states, the service life of the multistable mechanism is greatly improved. In addition, due to the ability of the first flexible bistable mechanism to resist out-of-plane deformation, when the stable position of the multistable mechanism in this embodiment is switched to a plane direction perpendicular to the motion plane of the first flexible bistable mechanism 1, the overall structure It has good stability and will not affect the consistency of motion behavior due to out-of-plane deflection.

Example 2

In another typical implementation of the present invention, as shown in Figures 7-12, a spatial multi-stable mechanism is proposed, including a first flexible bistable mechanism 1 and a second flexible bistable mechanism 7 and a flexible actuator 2. The first flexible bistable mechanism 1 and the second flexible bistable mechanism 7 are symmetrically fixed and installed at both ends of the flexible actuator 2. As shown in Figure 7, the first stable state is the first The initial states of the flexible bistable mechanism 1 and the second flexible bistable mechanism 7, and the first flexible bistable mechanism 1 and the second flexible bistable mechanism 7 in the first stable state are all dome-shaped, and the The first flexible bistable mechanism 1 and the second flexible bistable mechanism 7 both bend toward the flexible actuator 2 .

The structure of the second flexible bistable mechanism 7 is the same as that of the first flexible bistable mechanism 1 , and is composed of two sets of first flexible beams 9 . Each set of first flexible beams 9 consists of two circular arches arranged in parallel up and down. It consists of first flexible beams 9. The adjacent ends of the two groups of first flexible beams 9 are fixedly connected together through the second mover 6. A first rigid beam 10 is fixed at the middle position of each first flexible beam 9. , two sets of first flexible beams 9 are symmetrically arranged on both sides of the second mover 6 , and a second fixed end 8 is fixedly installed at both ends of the second flexible bistable mechanism 7 .

The two second fixed ends 8 are symmetrically arranged along the center line of the flexible actuator 2 , and the two second fixed ends 8 and the two first fixed ends 4 are symmetrically arranged along the center line of the flexible actuator 2 .

The structure of the flexible actuator 2 in this embodiment is the same as that of the flexible actuator 2 in Embodiment 1. The specific details will not be described too much here. The two ends of the flexible actuator 2 are connected to the adjacent first mover 5 respectively. , the second mover 6 is fixedly connected together.

The spatial steady-state motion of the spatial multi-stable mechanism in this embodiment is specifically as follows (the X-axis, Y-axis, and Z-axis directions are the same as in Embodiment 1):

As shown in Figure 8, the second stable state is that in spatial coordinates, the end effector 3 of the flexible actuator 2 is displaced in the negative direction of the X-axis, causing the flexible actuator 2 to deflect to the left. The first flexible double The stable mechanism 1 displaces downward and reaches a stable state, and the second flexible bistable mechanism 7 displaces upward and reaches a stable state;

As shown in Figure 9, the third stable state is that in spatial coordinates, the end effector 3 of the flexible actuator 2 is displaced in the positive direction of the X-axis, causing the flexible actuator 2 to shift to the right. The first flexible double The stable mechanism 1 displaces downward and reaches a stable state, and the second flexible bistable mechanism 7 displaces upward and reaches a stable state;

As shown in Figures 10 and 11, the fourth stable state is that in spatial coordinates, the end effector 3 of the flexible actuator 2 is subject to a displacement in the positive Y-axis direction, causing the flexible actuator 2 to deflect in the positive direction of the Y-axis. , the first flexible bistable mechanism 1 displaces downward and reaches a stable state, and the second flexible bistable mechanism 7 displaces upward and reaches a stable state;

As shown in Figure 12, the fifth stable state is that in the spatial coordinates, the end effector 3 of the flexible actuator 2 is subjected to a negative Y-axis displacement, causing the flexible actuator 2 to deflect in the negative direction of the Y-axis. The first The flexible bistable mechanism 1 is displaced downward and reaches a stable state, and the second flexible bistable mechanism 7 is displaced upward and reaches a stable state.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A spatial multi-stable mechanism, including a vertically arranged flexible actuator. At least one end of the flexible actuator is connected in series with a flexible bistable mechanism. Both ends of the flexible bistable mechanism are fixedly installed with a fixed end. It is characterized in that the initial state of the flexible bistable mechanism is an arch shape, a mover is provided at the center of the flexible bistable mechanism and is fixedly connected to the end of the flexible actuator, and the flexible actuator consists of an end The actuator and the flexible beam assembly are symmetrically fixed and installed on both sides of the end effector. The flexible bistable mechanism vertically displaces when the end effector moves linearly in the direction perpendicular to the axis of the flexible actuator to provide the end effector with a vertical displacement. The force that deflects the actuator from the initial equilibrium position to the buckling position and resists the reaction force of the flexible actuator deformation. 2. A space multi-stable mechanism according to claim 1, characterized in that the flexible bistable mechanism is bent toward the flexible actuator, and the flexible bistable mechanism is composed of two sets of first flexible beams. The first flexible beams are symmetrically arranged on both sides of the first mover, and adjacent ends of the two sets of first flexible beams are fixedly connected together through the first mover. 3. A space multi-stable mechanism according to claim 2, characterized in that each group of first flexible beams is composed of two arc-shaped first flexible beams arranged in parallel up and down, and each first flexible beam A first rigid beam is fixed at the middle position. 4. A spatial multi-stable mechanism according to claim 3, characterized in that the first flexible beam and the first rigid beam have the same circle center. 5. A spatial multi-stable mechanism according to claim 1, characterized in that the flexible actuator has a square cross-section. 6. A spatial multi-stable mechanism according to claim 1, characterized in that each group of the flexible beams is vertically enclosed by four second flexible beams with a square cross-section, and the four second flexible beams in the same group are vertically enclosed. The adjacent ends of the two flexible beams are fixedly connected together through the second rigid beam. 7. A spatial multi-stable mechanism according to claim 1, wherein the fixed end is provided with bolt holes for bolt fixing. 8. A spatial multi-stable mechanism according to claim 1, characterized in that the end effector has a square cross-section, and the end effector is not stressed in the initial state. 9. A spatial multi-stable mechanism according to claim 1, wherein the cross-sectional area of the end effector is the same as the cross-sectional area of the flexible beam group. 10. A spatial multi-stable mechanism according to claim 1, characterized in that two adjacent fixed ends are arranged symmetrically along the center line of the flexible actuator.