Flexible micro clamp with three-dimensional bridge type hinge

Abstract

The invention discloses a flexible micro clamp with a three-dimensional bridge type hinge. The flexible micro clamp comprises clamp arms, a half-bridge type three-dimensional hinge and an input base. The two clamp arms are oppositely arranged in parallel, each clamp arm comprises two flexible arms, the tail ends of the two flexible arms can be connected in a relatively rotating mode, the flexible arms are connected with the input base and are of a V-shaped symmetrical structure, and the flexible arms are of a thin plate structure; the half-bridge type three-dimensional hinge is erected on the clamp arm arrangement plane in a three-dimensional mode and has a certain width, the two flexible ends of the half-bridge type three-dimensional hinge are connected with the two flexible arms respectively to form a deformation angle, expansion and contraction movement of the two flexible arms generates uneven distribution stress in the width direction of the flexible ends of the half-bridge type three-dimensional hinge, and the half-bridge type three-dimensional hinge guides the flexible arms to generate y-direction deformation. According to the micro-clamp, the overall structure is reasonably optimized by innovating the combined structure, the structure is simple, the plane arrangement is more compact, the production cost is low, clamping is achieved by innovatively utilizing the characteristics between the half-bridge type three-dimensional hinge and the clamp arms based on the lever mechanism and the bridge type amplification mechanism, and the driving and zooming structure design of the micro-clamp is enriched.

Description

Technical Field

[0001] This invention relates to the field of micro-nano manipulation technology, specifically to a flexible micro-clamp with a three-dimensional bridge hinge. Background Technology

[0002] With the rapid development of microelectronics technology, microelectromechanical systems (MEMS) technology has had a significant impact on many fields such as advanced manufacturing technology, biomedicine, aerospace, national defense, and people's lives, making it one of the most promising research fields and leading industries in the 21st century. As MEMS technology develops, micro-devices with different functions need to be assembled to form MEMS systems, which requires micromanipulation technology. Micromanipulation technology is also a key link in the industrialization of MEMS technology, thus the demand for micromanipulation technology is becoming increasingly urgent.

[0003] Micro-assembly and micro-manipulation refer to the assembly of multiple tiny parts into a relatively complex microelectromechanical system. As the end effector in micro-manipulation and micro-assembly, the micro clamp directly contacts the object being clamped during the micro-manipulation and micro-assembly process, and its clamping performance directly affects the quality of operation. The driving methods of the micro clamp include solenoid valves, motors, piezoelectric ceramic actuators, etc. Since the existing available drives have the problem of mismatch between the driving amount and output accuracy and the end output demand and accuracy, the micro clamp needs to be equipped with an amplification mechanism to amplify or reduce. The commonly used micro-displacement amplification mechanisms are mainly bridge amplification mechanisms and lever amplification mechanisms. The lever amplification mechanism has a simple structure and high power ratio, while the bridge amplification mechanism has a compact structure and high amplification factor. Each has its advantages.

[0004] The arrangement of the amplification mechanism in existing microgrips is relatively simple. Whether it is a multi-stage bridge mechanism, a multi-stage lever amplification mechanism, or a combination of bridge amplification and lever amplification, they are all arranged in a planar manner. That is, all amplification mechanisms are located on the same arrangement plane, and the clamping arms and end clamping directions of the microgrip mechanism are also located on this arrangement plane. Therefore, the compactness of the microgrip on the clamping plane is insufficient.

[0005] Therefore, this invention provides a flexible micro clamp with a three-dimensional bridge hinge. By innovatively arranging and applying the bridge mechanism and lever mechanism, the output of large displacement drive input is reduced, thereby improving control accuracy. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a flexible micro clamp with a three-dimensional bridge hinge to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A flexible micro-gripper with a three-dimensional bridge hinge includes a clamp arm, a half-bridge three-dimensional hinge, and an input base; wherein,

[0009] Two clamp arms are arranged in parallel opposite directions, with the middle of their ends forming the clamping area. Each clamp arm includes two flexible arms whose ends can be rotatably connected relative to each other. The roots of the two flexible arms are respectively connected to two input bases and have a V-shaped symmetrical structure. They are arranged on the xz plane. The flexible arms are thin plate structures with y-direction deformation flexibility.

[0010] Two input bases are used to input equal relative displacements to the roots of the two clamp arms, causing the two flexible arms to expand and contract with their ends as the rotation center. The roots of the flexible arms on the same side of the two clamp arms are fixed to the same input base.

[0011] The clamp arm is equipped with a semi-bridge-type three-dimensional hinge, which is three-dimensionally mounted on the clamp arm's layout plane and has a certain width. The two flexible ends of the semi-bridge-type three-dimensional hinge are respectively connected to two flexible arms and form a deformation angle with the flexible arms. The expansion and contraction movements of the two flexible arms generate unevenly distributed stress in the width direction of the flexible ends of the semi-bridge-type three-dimensional hinge. Under the guidance of the semi-bridge-type three-dimensional hinge, the flexible arms deform along the y-direction to achieve clamping.

[0012] According to one aspect of this disclosure, the two half-bridge three-dimensional hinges are arranged separately, symmetrically on the outer side of the clamp arm. The half-bridge three-dimensional hinge includes a rigid intermediate body and two first flexible support beams. The root ends of the two first flexible support beams are respectively connected to both sides of the rigid intermediate body, and their flexible ends are respectively connected to the outer sides of the two flexible arms of the same clamp arm. The stiffness of the first flexible support beam at the connection center point with the flexible arm is less than the stiffness of the half-bridge three-dimensional hinge.

[0013] According to one aspect of this disclosure, the half-bridge three-dimensional hinges on the two clamp arms are arranged in a combined manner, and the two are combined into a whole structure of a full-bridge three-dimensional hinge. The full-bridge three-dimensional hinge includes a stationary intermediate body and four second flexible support beams. The root ends of the four second flexible support beams are respectively connected to the four edges of the stationary intermediate body, and their flexible ends are respectively connected to the inner surfaces of the four flexible arms. The stationary intermediate body is located on the symmetrical center plane of the two clamp arms.

[0014] According to one aspect of this disclosure, the two flexible arms are an integral structure, and their ends are connected by a flexible arc-shaped beam to provide relative rotational freedom between the two flexible arms and improve the clamping flexibility of the clamp arms.

[0015] According to one aspect of this disclosure, a semi-bridge three-dimensional hinge is arranged on the xy plane, with its width direction along the z direction, and its flexible end is parallel to the z direction and connected to the flexible arm.

[0016] According to one aspect of this disclosure, the ends of the two flexible arms are provided with clearance structures to create clearance spaces for the expansion and contraction movements of the two flexible arms.

[0017] According to one aspect of this disclosure, the flexible end of the semi-bridge three-dimensional hinge is connected to the flexible arm via an integrally formed reinforcing structure.

[0018] According to one aspect of this disclosure, a driving device is provided at the symmetrical center position of the two input bases, the driving device having a bidirectional driving end for inputting equal relative displacements to the two input bases.

[0019] According to one aspect of this disclosure, strain sensors are installed at the end of the flexible arm and the flexible end of the semi-bridge three-dimensional hinge for coordinated control of clamping displacement and clamping force.

[0020] Compared with the prior art, the flexible micro clamp with a three-dimensional bridge hinge of the present invention has the following beneficial effects:

[0021] By arranging semi-bridge-type three-dimensional hinges on two thin-plate clamp arms, the horizontal driving displacement input from the two input bases is transformed into the vertical clamping displacement of the two clamp arms. Based on the lever mechanism and the bridge amplification mechanism, the scaling control of input and output is achieved. This invention optimizes the overall structure of the micro clamp through innovative combination structure. The micro clamp structure is simple, more compact in planar arrangement, and has low production cost. Moreover, it innovatively utilizes the characteristics of the semi-bridge-type three-dimensional hinge and the clamp arms to achieve clamping, which is different from the implementation principle of existing micro clamp technologies, enriching the design method of micro clamp driving and scaling structure. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the flexible micro-clamping device in Example 1;

[0023] Figure 2 This is a side view of the flexible microgripper of Embodiment 1;

[0024] Figure 3 This is a top view of the flexible microgripper in Embodiment 1;

[0025] Figure 4 This is a top view of the flexible microgripper in Embodiment 2;

[0026] Figure 5 This is a front view of the flexible micro-gripper of Embodiment 1;

[0027] Figure 6 This is a strain simulation diagram of the flexible microclamp from Example 1;

[0028] Figure 7 This is another strain simulation diagram of the flexible microclamp from Example 1;

[0029] Figure 8 This is a stress simulation diagram of the flexible micro clamp in Example 1.

[0030] In the diagram: 1. Input base; 2. Clamping arm; 21. Flexible arc beam; 22. Clearance space; 23. Flexible arm; 3. Semi-bridge three-dimensional hinge; 31. First flexible support beam; 32. Rigid intermediate body; 33. Second flexible support beam; 34. Static intermediate body; 35. Reinforcing structure; a. Deformation angle; f. Oblique angle; L1. First structural segment; L2. Second structural segment. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely the best embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The term "embodiment" as used herein means that a particular method, step, or content described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] This invention provides a flexible micro clamp with a three-dimensional bridge hinge, such as... Figures 1-5 As shown, it includes a clamp arm 2 formed into a single structure by wire cutting, a half-bridge three-dimensional hinge 3, and an input base 1. Unlike the clamp structure design of existing structures, the half-bridge three-dimensional hinge 3 on the flexible micro clamp of this embodiment is three-dimensionally mounted on the plane of the clamp arm 2, realizing the amplification of the output displacement and guiding the clamp arm 2 to perform clamping and releasing movements perpendicular to the plane of the clamp arm 2. Specifically,

[0034] Two clamping arms 2 are arranged in parallel and opposite directions, with a deformation space in the middle of them. A clamping area for clamping materials is formed between their ends. The clamping arms 2 include two flexible arms 23 whose ends can be rotatably connected to each other. The roots of the two flexible arms 23 are respectively connected to two input bases 1 and arranged in a V-shaped symmetrical structure on the xz plane. The two input bases 1 are input with equal relative displacements from the roots of the two flexible arms 23. The two flexible arms 23 use their rotatable fulcrums at their ends as the rotation center to generate expansion or contraction movements.

[0035] To ensure that the two clamp arms 2 have equal and synchronous input, the two clamp arms 2 share a single drive device, and the root of the flexible arm 23 on the same side of the two clamp arms 2 is fixed to the same input base 1.

[0036] The semi-bridge three-dimensional hinge 3 is the core component of this embodiment. It connects to the clamp arm 2. Since the flexible arm 23 is a thin plate structure, it has y-direction deformation flexibility. The semi-bridge three-dimensional hinge 3 spans the two flexible arms 23 and is arranged three-dimensionally above the xz plane, and can generate elastic deformation component force in the z direction. At the same time, the two flexible ends of the semi-bridge three-dimensional hinge 3 are respectively connected to the two flexible arms 23 and have a certain width. Under the expansion and contraction movement of the two flexible arms 23 with an inclined angle f, different displacement inputs are formed in the width direction of the flexible ends of the semi-bridge three-dimensional hinge 3, generating unevenly distributed stress in the width direction. As a result, the semi-bridge three-dimensional hinge 3 produces bridge deformation, generating unequal forces to adapt to the gradient change of stiffness of the flexible arms 23, guiding the flexible arms 23 to deform along the y direction to achieve clamping.

[0037] Example 1: Based on the basic structural principle of the flexible micro-gripper described above, this example provides a flexible micro-gripper with a three-dimensional bridge hinge; the two half-bridge three-dimensional hinges 3 in this example are arranged separately, as follows: Figures 1-3 As shown, the two are symmetrically bridged on the outside of the clamp arm 2. The semi-bridge three-dimensional hinge 3 includes a rigid intermediate body 32 and two first flexible support beams 31. The rigid intermediate body 32 provides rigid support. The root ends of the two first flexible support beams 31 are respectively connected to both sides of the rigid intermediate body 32, and their flexible ends are respectively connected to the outer sides of the two flexible arms 23 of the same clamp arm 2. The first flexible support beams 31 form a deformation angle α with the xz plane.

[0038] In order for the half-bridge three-dimensional hinge 3 to guide and drive the clamp arm 2 to move relative to the clamping position during the expansion movement of the clamp arm 2, the stiffness of the first flexible support beam 31 at the connection center point with the flexible arm 23 is less than the stiffness of the half-bridge three-dimensional hinge 3. Therefore, the tensile deformation of the half-bridge three-dimensional hinge 3 drives the rigid intermediate body 32 to move inward. Since the clamp arm 2 with thin plate structure has smaller deformation flexibility, and under the uneven force to adapt to the gradient stiffness of the clamp arm 2, the half-bridge three-dimensional hinge 3 pushes and guides the clamp arm 2 to flex and deform towards the clamping area, thereby realizing the clamping action; the release action of the clamp arm 2 is the reverse operation, which will not be described further here.

[0039] As a further technical solution of this embodiment, the two flexible arms 23 are rotatably connected. The connection method can be a pin connection or a flexible hinge connection, and a clamping plate adapted to the shape of the material can be set at the connection. This embodiment does not limit this. As a preferred technical solution of this embodiment, the two flexible arms 23 are connected at their ends by a flexible arc beam 21 that is integral with it. This not only meets the requirement of relative rotation between the two, but the flexible arc beam 21 also has a certain degree of resilience, maintaining a reliable connection between the input base 1 and the drive device during expansion and contraction. In addition, the flexible arc beam 21 also has a certain degree of y-direction flexibility, which can meet the requirement of flexible and non-destructive clamping of materials.

[0040] As a further technical solution of this embodiment, in order to reduce the coupling effect of the half-bridge three-dimensional hinge 3 in the direction other than y, the half-bridge three-dimensional hinge 3 is arranged on the xy plane, with its width direction along the z direction, and its flexible end is parallel to the z direction and connected to the flexible arm 23. The length of the first flexible support beam 31 is consistent in each xy section.

[0041] In addition, such as Figure 1 As shown, the relative angles at the ends of the two flexible arms 23 are cut off to form a clearance structure. The two clearance structures form a clearance space 22 for the expansion and contraction of the two flexible arms 23. Since the flexible arm 23 is a thin plate structure, and the connection node between the flexible end of the semi-bridge three-dimensional hinge 3 and the flexible arm 23 is a stress concentration area, especially the lower section of the connection node, the flexible end of the semi-bridge three-dimensional hinge 3 is integrally formed with a reinforcing structure 35 to increase the connection area with the flexible arm 23 and enhance the rigidity of the connection node, so that the force of the first flexible support beam 31 is evenly applied to the flexible arm 23.

[0042] As a further technical solution of this embodiment, the driving device (not shown in the figure) is set at the symmetrical center position of the two input bases 1. The driving device can be a piezoelectric actuator, a high-precision small-stroke linear motor, or a stepper motor. In order to input equal synchronous bidirectional drive to the two input bases 1, the driving device should have a bidirectional driving end. In addition, a strain sensor is installed on the outer side of the end of the flexible arm 23 and near the flexible end of the half-bridge three-dimensional hinge 3. According to the characteristic curve of the micro clamp, by monitoring the force of the half-bridge three-dimensional hinge 3 on the flexible arm 23 and the clamping displacement of the end of the clamp arm 2, the clamping displacement and clamping force of the clamp arm 2 are controlled in a coordinated manner, and a closed-loop control is formed with the input of the driving device.

[0043] The flexible micro-clamp of this embodiment, guided and amplified by the semi-bridge-type three-dimensional hinge 3, can achieve flexible clamping at the millimeter, micrometer, and nanometer scales, such as... Figure 6 Each of the two input bases 1 is given a displacement of 0.1mm, such as... Figure 7 As shown, the ends of the two clamping arms 2 come together to achieve clamping and generate a displacement output of 0.6mm, which has a displacement amplification effect of 6 times; as Figure 5As shown, according to the lever principle, the displacement amplification at the ends of the two clamp arms 2 is related to the setting position of the half-bridge three-dimensional hinge 3. Simulation data shows that the amplification factor is proportional to L1 / L2. The closer the half-bridge three-dimensional hinge 3 is to the root of the flexible arm 23, the greater its amplification factor. However, the root of the flexible arm 23 has greater rigidity. Therefore, in order to achieve the flexural deformation of the flexible arm 23, the overall flexibility of the flexible arm 23 must be greater, that is, the less rigid it is. The rigidity of the half-bridge three-dimensional hinge 3 must be greater. It can be seen that the amplification factor is also proportional to the flexibility of the clamp arm 2 and the rigidity of the half-bridge three-dimensional hinge 3. In addition, the amplification factor is also related to the structure of the half-bridge three-dimensional hinge 3, that is, it is related to the deformation angle α of the first flexible support beam 31. Simulation data shows that the amplification factor is proportional to cot(a).

[0044] The flexible micro-clamp experiences the following force under a displacement input of 0.1 mm: Figure 8 As shown, the upper and lower sections of the flexible end of the semi-bridge three-dimensional hinge 3 are subjected to significantly different forces, indicating that the clamp arm 2 can undergo flexural deformation under unevenly distributed forces with smaller upper sections and larger lower sections. Moreover, the maximum stress is only 174 MPa, which is much less than the required stress of aluminum alloy materials, indicating that the flexible micro clamp meets the existing design and application requirements.

[0045] Example 2: This example provides another flexible micro clamp with a three-dimensional bridge hinge. The two half-bridge three-dimensional hinges 3 are arranged in a combined manner. The difference between this example and Example 1 lies only in the structure and arrangement of the half-bridge three-dimensional hinges 3. Figure 4 As shown;

[0046] Unlike the outer arrangement in Embodiment 1, the half-bridge three-dimensional hinge 3 in this embodiment is arranged between the two clamp arms 2. The two half-bridge three-dimensional hinges 3 are combined back to back into a full-bridge three-dimensional hinge structure by sharing a stationary intermediate body 34. The stationary intermediate body 34 is located on the symmetry center plane of the two clamp arms 2. Under the application of the same magnitude and opposite direction of the forces applied by the two symmetrical clamp arms 2, it remains stationary on the symmetry center plane. The stationary state expressed here refers to the stationary state on the xy relative cross section. As the clamp arms 2 expand and contract, the full-bridge three-dimensional hinge as a whole moves along the z direction.

[0047] The root ends of the four second flexible support beams 33 are respectively connected to the four edges of the stationary intermediate body 34, and their flexible ends are respectively connected to the inner sides of the four flexible arms 23. Similarly, the flexible arms 23 and the xz plane form a deformation angle α. Under the rigid support and symmetrical force of the stationary intermediate body 34, the clamping arm 2 expands and contracts, and the two half-bridge three-dimensional hinges 3 extend and deform to guide the clamping action of the clamping arm 2. Unlike the first embodiment, the half-bridge three-dimensional hinges 3 can be set at any position of the flexible arm 23, without being limited by the relative stiffness between the two. Its magnification factor is also proportional to L1 / L2 and the deformation angle α.

[0048] The remaining structures of the flexible micro-clamp in this embodiment can be further optimized by referring to Embodiment 1, and will not be described again here.

[0049] The directional or positional terms such as "x", "y", "z", "end", "side", "inner", "outer", "up", and "down" mentioned in this article are based on... Figures 1-5 The coordinate system or orientation relationship shown is used. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a particular orientation, or to be constructed and operated in a particular orientation;

[0050] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the terms "above" and "inside" may, in certain circumstances, indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flexible micro-gripper with a three-dimensional bridge hinge, characterized in that: Includes clamp arms, a half-bridge type three-dimensional hinge, and an input base; among which, The two clamp arms are arranged in parallel opposite directions, with the middle of their ends forming a clamping area. Each clamp arm includes two flexible arms whose ends can be rotatably connected relative to each other. The roots of the two flexible arms are respectively connected to the two input bases and arranged in a V-shaped symmetrical structure on the xz plane. The flexible arms are thin plate structures with y-direction deformation flexibility. The two input bases are used to input equal relative displacements to the roots of the two clamp arms, causing the two flexible arms to expand and contract with their ends as the rotation center. The roots of the flexible arms on the same side of the two clamp arms are fixed to the same input base. The clamp arm is equipped with a semi-bridge-type three-dimensional hinge, which is three-dimensionally mounted on the clamp arm's arrangement plane and has a certain width. The two flexible ends of the semi-bridge-type three-dimensional hinge are respectively connected to the two flexible arms and form a deformation angle with the flexible arms. The expansion and contraction movements of the two flexible arms generate unevenly distributed stress in the width direction of the flexible ends of the semi-bridge-type three-dimensional hinge. Under the guidance of the semi-bridge-type three-dimensional hinge, the flexible arms deform along the y-direction to achieve clamping.

2. The flexible micro-clamp with a three-dimensional bridge hinge according to claim 1, characterized in that: The two semi-bridge-type three-dimensional hinges are arranged separately, symmetrically on the outside of the clamp arm. Each semi-bridge-type three-dimensional hinge includes a rigid intermediate body and two first flexible support beams. The root ends of the two first flexible support beams are respectively connected to both sides of the rigid intermediate body, and their flexible ends are respectively connected to the outer sides of the two flexible arms of the same clamp arm. The stiffness of the first flexible support beam at the connection center point with the flexible arm is less than the stiffness of the semi-bridge-type three-dimensional hinge.

3. The flexible micro-clamp with a three-dimensional bridge hinge according to claim 1, characterized in that: The two clamp arms are arranged in a combined manner, forming a full-bridge three-dimensional hinge. The full-bridge three-dimensional hinge includes a stationary intermediate body and four second flexible support beams. The root ends of the four second flexible support beams are respectively connected to the four edges of the stationary intermediate body, and their flexible ends are respectively connected to the inner surfaces of the four flexible arms. The stationary intermediate body is located on the symmetrical center plane of the two clamp arms.

4. The flexible micro clamp with a three-dimensional bridge hinge according to any one of claims 1 to 3, characterized in that: The two flexible arms are an integral structure, and their ends are connected by a flexible arc beam, which provides relative rotational freedom between the two flexible arms and improves the clamping flexibility of the clamping arms.

5. The flexible micro-clamp with a three-dimensional bridge hinge according to claim 4, characterized in that: The semi-bridge-type three-dimensional hinge is arranged on the xy plane, with its width direction along the z direction, and its flexible end is parallel to the z direction and connected to the flexible arm.

6. The flexible micro-clamp with a three-dimensional bridge hinge according to claim 4, characterized in that: The ends of the two flexible arms are provided with clearance structures to create clearance spaces for the expansion and contraction movements of the two flexible arms.

7. The flexible micro clamp with a three-dimensional bridge hinge according to claim 4, characterized in that: The flexible end of the semi-bridge three-dimensional hinge is connected to the flexible arm through an integrally formed reinforcing structure.

8. The flexible micro clamp with a three-dimensional bridge hinge according to claim 4, characterized in that: A driving device is provided at the symmetrical center position of the two input bases. The driving device has a bidirectional driving end for inputting equal relative displacements to the two input bases.

9. The flexible micro-clamp with a three-dimensional bridge hinge according to claim 7, characterized in that: Strain sensors are installed at the end of the flexible arm and the flexible end of the semi-bridge three-dimensional hinge to coordinate the control of clamping displacement and clamping force.

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