Flexible multi-rod joint

Abstract

A traditional multi-rod connecting structure generally adopts a rigid fixed joint (such as a multi-way pipe joint), the relative poses of ports of the traditional multi-rod connecting structure are in a fixed geometrical relationship, and the traditional multi-rod connecting structure can only adapt to static structure construction and is difficult to adapt to scenes needing dynamic deformation. According to an existing flexible joint technology, the deformation capacity is achieved through an elastic material, but the following defects still exist: deformation concentration is insufficient, elastic deformation is distributed on the whole of a joint but not local, and consequently the axes of a plurality of rod pieces deviate from a preset rotation center; the motion range and rigidity are unbalanced, the motion range of rod pieces is limited, interference is generated when adjacent rod pieces are excessively close to each other, and the structural deformation flexibility is insufficient due to the fact that the overall elasticity modulus of a connector is too high; the multi-degree-of-freedom deformation capacity of the flexible multi-rod joint is achieved through the deformable part made of the continuous flexible component, and the flexible multi-rod joint can be used for building a frame structure and a connecting rod mechanism.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of joint especially relates to a flexible multi -rod joint. TECHNICAL BACKGROUND

[0002] Traditional multi -rod connecting structure generally adopts rigid fixed joint (for example multi -way pipe joint), and the relative pose between its port is fixed geometric relation, can only adapt static structure to build, and it is difficult to adapt to the scene needing dynamic deformation.The existing flexible joint technology (such as CN202210499372.8) realizes deformation ability through elastic material, but still has the following defects: deformation concentration is insufficient, and elastic deformation is distributed in the whole joint instead of locally, resulting in the axis of multiple rods deviating from the preset rotation center;Motion range and rigidity are unbalanced, and the motion range of the rod is limited, adjacent rods are too close to interfere, and because the overall elastic modulus of the joint is too high, the structure deformation flexibility is insufficient. SUMMARY

[0003] In view of the deficiencies of the prior art, the utility model provides a flexible multi -rod joint, and the scheme is as follows:

[0004] A flexible multi -rod joint, characterized by comprising:

[0005] At least one non-fixed joint, the inner end of the non-fixed joint is connected to a deformable part, and the outer end is provided with a connecting structure for assembling a rod piece;

[0006] The deformable part is a continuous flexible member, and its overall flexibility satisfies that when the non-fixed joint is subjected to external force, the deformable part can deform to make the non-fixed joint fit adjacent joints;

[0007] The configuration of the flexible multi -rod joint satisfies any one of the following:

[0008] (a) containing only fixed joint, the fixed joint is connected with at least one non-fixed joint through a deformable part;

[0009] (b) not containing fixed joint, having at least two non-fixed joints, each non-fixed joint is connected with a deformable part, and all deformable parts converge at the same center.

[0010] When containing fixed joint, the fixed joint is one of the following structures:

[0011] (a) single shaft sleeve structure, with single rod coaxial connection cavity;

[0012] (b) double-cavity sleeve structure, containing two independent rod connecting cavities formed by axial separation;

[0013] (c) A multi-port joint structure with at least three rod connection ports.

[0014] Optionally, the ratio of the minimum width to the maximum width of any cross section of the deformable part is ≥1:2, and its cross-sectional area is equal to or less than the cross-sectional area of ​​the inner end of the non-fixed joint; the cross-sectional area of ​​the non-fixed joint increases unidirectionally from the inner end to the outer end, and the change mode includes continuous gradual change, step abrupt change or a combination thereof.

[0015] Furthermore, the inner and outer ends of the non-fixed joint have circular cross-sections; the cone angle formed by the line connecting the outer and inner ends of the non-fixed joint is ≤60 degrees to avoid spatial interference when adjacent members are close together; the length of the deformable part is less than the diameter of the outer end to provide effective constraint on the members; the length of the deformable part is defined as follows:

[0016] (a) When it includes a single fixed connector, the length is the vertical distance from the inner end of the non-fixed connector to the outer surface of the fixed connector;

[0017] (b) When not including fixed joints, the length is the distance from the inner end of the non-fixed joint to the convergence center.

[0018] Optionally, the deformable part is a thin-walled sheet structure, with the ratio of its thickness dimension to its width dimension ≤ 1:4; the thickness of the thin-walled sheet structure is equal to or less than the thickness of the inner cross-section of the non-fixed connector.

[0019] Furthermore, the cross-sectional thickness of the non-fixed joint increases unidirectionally from the inner end to the outer end, and the change can be continuous gradual change, stepwise abrupt change, or a combination thereof.

[0020] Furthermore, the width of the deformable part is greater than the width of the cross-section of the outer end of the non-fixed joint; the width of the cross-section of the non-fixed joint increases unidirectionally from the outer end to the inner end, and the change mode includes continuous gradual change, step abrupt change or a combination thereof.

[0021] Optionally, the non-fixed joint, the deformable part, and the optionally present fixed joint constitute an integrally molded structure; the integrally molded structure is formed by injection molding or additive manufacturing processes.

[0022] Optionally, when a fixed joint is not included, the deformable part consists of at least one rope, which is integrally formed or formed by twisting or spirally winding multiple strands of fiber.

[0023] Furthermore, when the number of deformable parts is N (N≥2), there are N ropes, each rope is divided into a first segment and a second segment, and the following conditions are met:

[0024] The second segment of the i-th rope is connected to the first segment of the (i+1)-th rope to form the i-th deformable part (i∈[1,N-1]);

[0025] The second segment of the Nth rope is connected to the first segment of the 1st rope to form the Nth deformable section.

[0026] By adopting the above technical solution, this utility model has the following beneficial effects:

[0027] The deformable part made of continuous flexible components enables the multi-degree-of-freedom deformation capability of flexible multi-bar joints, which can be used to build frame structures and linkage mechanisms, specifically as follows:

[0028] When the ratio of the minimum width to the maximum width of any cross section of the deformable part is ≥1:2, the non-fixed joint obtains the ability to move around a point with three degrees of freedom. Its cross-sectional area increases unidirectionally from the inside to the outside and the cone angle of the line connecting the inner and outer ends is ≤60°, which effectively avoids interference when adjacent members are close together.

[0029] Non-fixed joints, deformable parts, and optional fixed joints are integrally formed through injection molding / additive manufacturing processes, reducing manufacturing costs. The length of the deformable part is less than the outer diameter, and with the cross-sectional design that gradually increases from the inside to the outside, the deformation area is more concentrated near the center, and the axial offset of each member is controlled, so the frame built by this type of flexible multi-rod joint has higher precision.

[0030] The thin-walled sheet-like deformable part forms a single degree of freedom bending constraint, and its thickness increases from the inside to the outside, which effectively avoids interference when adjacent rods are close together. The width of the deformable part is greater than the cross-section of the outer end, and the cross-sectional width of the non-fixed joint increases unidirectionally from the outer end to the inner end, which is conducive to enhancing the single degree of freedom bending constraint. As a result, the linkage mechanism built by this kind of flexible multi-bar joint has better stability.

[0031] The use of ropes as deformable parts significantly improves flexibility; the metal ropes are also corrosion-resistant, and the segmented configuration supports multi-node expansion, enabling the connection of any number of joints. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, 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 undue limitation of the present invention. In the drawings:

[0033] Figure 1 A flexible multi-rod joint that does not include a fixed joint;

[0034] Figure 2 It is a flexible multi-rod joint with a fixed connector and a single-axis sleeve structure;

[0035] Figure 3It is a flexible multi-rod joint with a fixed connector and a double-cavity sleeve structure;

[0036] Figure 4 It is a flexible multi-rod joint with a fixed connector and a multi-port joint structure;

[0037] Figure 5 The deformable part is a sheet-like flexible multi-rod joint;

[0038] Figure 6 It is a flexible multi-rod joint with a deformable sheet-like part and a width greater than the outer end diameter;

[0039] Figure 7 It is a flexible multi-rod joint with a deformable sheet-like part and including a fixed joint;

[0040] Figure 8 A flexible multi-rod joint with a deformable part being a rope;

[0041] Figure 9 It is a tetrahedral frame assembled using flexible joints;

[0042] Figure 10 It is a linkage mechanism assembled using flexible joints;

[0043] In the diagram: 1. Non-fixed connector; 2. Deformable part; 3. Center; 4. Fixed connector; 5. Set screw; 10. Inner end; 11. Outer end; 20. Rope; 40. Separator; Detailed Implementation

[0044] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other. In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0046] See Figure 1 In some embodiments, the flexible multi-rod joint includes multiple non-fixed joints (1), the inner end (10) of which is connected to a deformable part (2), the deformable parts (2) converge at the same center (3), and the outer end (11) is provided with a connection structure for assembling rods by an interference fit process; the deformable part (2) is a continuous flexible component, and its overall flexibility satisfies that: when the non-fixed joint (1) is subjected to external force, the deformable part (2) can deform to make the non-fixed joint (1) fit against the adjacent joint; the material of the deformable part (2) includes, but is not limited to, elastomeric materials such as silicone, TPU, and TPE. The deformable part (2) is formed by injection molding or additive manufacturing processes. The cross-section of the deformable part (2) is circular, and the ratio of the minimum width to the maximum width is 1:1. Its cross-sectional area is equal to or less than the cross-sectional area of ​​the inner end (10) of the non-fixed joint (1). The cross-sectional area of ​​the non-fixed joint (1) increases unidirectionally from the inner end (10) to the outer end (11), and the change is a continuous gradual change. The cross-sections of the inner end (10) and the outer end (11) of the non-fixed joint (1) are circular. The cone angle formed by the line connecting the outer end (11) and the inner end (10) of the non-fixed joint (1) is ≤60 degrees to avoid spatial interference when adjacent rods are close together. The length L of the deformable part (2) is less than the diameter R of the outer end (11), so that the deformation area is more concentrated near the center (3), and the offset of the axis of each rod is controlled.

[0047] See Figure 2 In some embodiments, the flexible multi-rod joint includes a single fixed joint (4), which is a single-axis sleeve structure with a single rod coaxial connection cavity;

[0048] See Figure 3 In some embodiments, the flexible multi-rod joint includes a single fixed joint (4), which is a double-cavity sleeve structure containing two independent rod connection cavities formed by axial separation (40);

[0049] See Figure 4In some embodiments, the flexible multi-rod joint includes a single fixed joint (4), which is a multi-port joint structure having at least three rod connection ports.

[0050] See Figure 5 In some embodiments, the deformable part (2) is a thin-walled sheet structure with a thickness-to-width ratio ≤ 1:4; the thickness of the thin-walled sheet structure is equal to or less than the cross-sectional thickness of the inner end (10) of the non-fixed joint (1); the cross-sectional thickness of the non-fixed joint (1) increases unidirectionally from the inner end (10) to the outer end (11), and the change is a continuous gradual change, thereby effectively avoiding interference when adjacent rods are close together.

[0051] See Figure 6 In some embodiments, the deformable part (2) is a thin-walled sheet structure, and the width of the deformable part (2) is greater than the width of the cross-section of the outer end (11) of the non-fixed joint (1); the cross-sectional width of the non-fixed joint (1) increases in one direction from the outer end (11) to the inner end (10), and the change is a continuous gradual change, thereby enhancing the single degree of freedom bending constraint.

[0052] See Figure 7 In some embodiments, the flexible multi-bar joint includes a single fixed joint (4), and the deformable part (2) is a thin-walled sheet structure; the cross-sectional thickness of the non-fixed joint (1) increases unidirectionally from the inner end (10) to the outer end (11), and the cross-sectional width of the non-fixed joint (1) increases unidirectionally from the outer end (11) to the inner end (10), thereby avoiding interference when adjacent bars are close together and enhancing single-degree-of-freedom bending constraints;

[0053] See Figure 8 In some embodiments, the flexible multi-rod joint does not include a fixed joint (4), and the deformable part (2) consists of at least one rope (20). The rope (20) is integrally formed or formed by twisting or spirally winding multiple strands of fiber. The rope (20) can be fixed with a top wire (5). When the number of deformable parts (2) is N (N≥2), there are N ropes (20), and each rope (20) is divided into a first segment and a second segment, and satisfies the following:

[0054] The second segment of the i-th rope (20) is connected to the first segment of the (i+1)-th rope (20) to form the i-th deformable part (2) (i∈[1,N-1]);

[0055] The second segment of the Nth rope (20) is connected to the first segment of the 1st rope (20) to form the Nth deformable part (2).

[0056] See Figure 9In some embodiments, the flexible multi-rod joint does not include the fixed joint (4), the deformable part (2) has a circular cross-section, and is used to build a tetrahedral frame structure. Adjacent joints do not interfere with each other, and the offset of the axis of each rod is controlled, thereby improving the assembly accuracy of the frame structure.

[0057] See Figure 10 In some embodiments, the flexible multi-bar joint does not include a fixed joint (4), and the deformable part (2) is a thin-walled sheet structure with a width greater than the width of the cross-section of the outer end (11) of the non-fixed joint (1), which enhances the single-degree-of-freedom bending constraint and thereby improves the stability of the linkage mechanism.

[0058] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A flexible multi-rod joint, characterized in that, include: At least one non-fixed joint, the inner end of which is connected to a deformable part, and the outer end of which is provided with a connecting structure for assembling rods; The deformable part is a continuous flexible component, and its overall flexibility satisfies the following: when the non-fixed joint is subjected to external force, the deformable part can deform to make the non-fixed joint fit with the adjacent joint. The configuration of the flexible multi-bar joint satisfies any one of the following: (a) When a single fixed joint is included, the fixed joint is connected to at least one non-fixed joint via a deformable portion; (b) When not containing a fixed joint, it has at least two non-fixed joints, each of which is connected to a deformable part, and all deformable parts converge at the same center.

2. The flexible multi-rod joint according to claim 1, characterized in that: When a fixed connector is included, the fixed connector has one of the following structures: (a) A single-axis sleeve structure with a single rod coaxially connected cavity; (b) A double-cavity sleeve structure comprising two independent rod-connecting cavities formed by axial separation; (c) A multi-port joint structure with at least three rod connection ports.

3. The flexible multi-rod joint according to claim 1, characterized in that: The ratio of the minimum width to the maximum width of any cross section of the deformable part is ≥1:2, and its cross-sectional area is equal to or less than the cross-sectional area of ​​the inner end of the non-fixed joint. The cross-sectional area of ​​the non-fixed joint increases unidirectionally from the inner end to the outer end, and the change can be continuous gradual change, stepwise abrupt change, or a combination thereof.

4. The flexible multi-rod joint according to claim 3, characterized in that: The inner and outer ends of the non-fixed connector have circular cross-sections; The cone angle formed by the line connecting the outer end and the inner end of the non-fixed joint is ≤60 degrees to avoid spatial interference when adjacent members are close together. The length of the deformable portion is less than the diameter of the outer end, so as to provide effective constraint on the rod; The length of the deformable portion is defined as follows: (a) When it includes a single fixed connector, the length is the vertical distance from the inner end of the non-fixed connector to the outer surface of the fixed connector; (b) When not including fixed joints, the length is the distance from the inner end of the non-fixed joint to the convergence center.

5. The flexible multi-rod joint according to claim 1, characterized in that: The deformable part is a thin-walled sheet structure, and the ratio of its thickness dimension to its width dimension is ≤1:4; The thickness of the thin-walled sheet structure is equal to or less than the thickness of the inner cross-section of the non-fixed connector.

6. The flexible multi-rod joint according to claim 5, characterized in that: The cross-sectional thickness of the non-fixed joint increases unidirectionally from the inner end to the outer end, and the change can be continuous gradual change, stepwise abrupt change, or a combination thereof.

7. The flexible multi-rod joint according to claim 5, characterized in that: The width of the deformable part is greater than the width of the cross-section of the outer end of the non-fixed joint; The cross-sectional width of the non-fixed joint increases unidirectionally from the outer end to the inner end, and the change can be continuous gradual change, stepwise abrupt change, or a combination thereof.

8. The flexible multi-bar joint according to any one of claims 1-7, characterized in that: The non-fixed joint, the deformable part, and the optional fixed joint constitute an integrally molded structure. The integrally molded structure is formed by injection molding or additive manufacturing processes.

9. The flexible multi-bar joint according to any one of claims 1, 3 or 4, characterized in that: When not including a fixed joint, the deformable part consists of at least one rope, which is integrally formed or formed by twisting or spirally winding multiple strands of fiber.

10. The flexible multi-bar joint according to claim 9, characterized in that: When the number of deformable parts is N (N≥2), there are N ropes, each rope is divided into a first segment and a second segment, and the following conditions are met: The second segment of the i-th rope is connected to the first segment of the (i+1)-th rope to form the i-th deformable part (i∈[1,N-1]). The second segment of the Nth rope is connected to the first segment of the 1st rope to form the Nth deformable section.

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