Buckling structure

Abstract

To provide a bent structure which can obtain a structure that is capable of turning in a small space in a multi-joint bent structure.SOLUTION: A bent structure comprises a plurality of first bent parts 9 and second bent parts 11 that are elastically bendable with respect to an axial direction, and an intermediate part 13 positioned between adjacent first bent part 9 and second bent part 11. The first bent part 9 and the second bent part 11 comprises a flexible component 17 integral in the axial direction. The intermediate part 13 is attached to the flexible component 17 between the adjacent first bent part 9 and second bent part 11, and suppresses bending of the flexible component 17 in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bending structure to be used in a joint function part of a robot, a manipulator, or the like. [Background technology]

[0002] As a conventional bending structure, for example, a multi-joint structure as disclosed in Patent Document 1 is known.

[0003] In this bending structure, the multiple bending pieces are rotatably connected to each other by a rotating shaft portion. Adjacent bending pieces are configured to rotate in directions perpendicular to each other, and the bending structure as a whole can be bent with a high degree of freedom.

[0004] However, in such a bending structure, the distance between bending pieces that bend in the same direction becomes long due to the presence of bending pieces that do not contribute to the bending, resulting in a structure that is difficult to turn around easily. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-237810 A Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved was the lack of maneuverability in multi-joint bending structures. [Means for solving the problem]

[0007] The present invention relates to a device that is elastically bendable in an axial direction. Axial bending The curved part, Applicable An intermediate portion located between adjacent bends; , a cord-like body for operation; The method comprises the steps of: AdjacentThe bent portions include flexible members integral with each other in the axial direction, and the intermediate portions are attached to the flexible members between the adjacent bent portions to suppress bending of the flexible members in the axial direction. death , The cord-like body is attached to the middle part. A flexure structure is provided. Effect of the Invention

[0008] According to the present invention, as long as bending of the flexible member between adjacent bent portions can be suppressed, the axial dimension of the intermediate portion can be reduced, resulting in a structure that is maneuverable by reducing the size of the portion that does not contribute to bending. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a bent structure according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view of the bending structure of FIG. 1 when not bent. [Diagram 3] FIG. 3 is an enlarged view showing a main part of FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view of the bent structure of FIG. 1 when bent. [Diagram 5] FIG. 5 is a vertical cross-sectional view of a bending structure according to a modified example when not bent. [Figure 6] FIG. 6 is a vertical cross-sectional view of a bending structure according to a modified example when bent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The objective of obtaining a structure with good maneuverability in a multi-joint bending structure has been achieved by attaching an intermediate section that suppresses bending between adjacent bending sections to a single flexible member that spans multiple bending sections.

[0011] That is, the bent structure (1) comprises a plurality of bent portions (9, 11) and an intermediate portion (13). The bent portions (9, 11) are elastically bendable in the axial direction. These bent portions (9, 11) comprise a flexible member (17) integral with them in the axial direction. The intermediate portion (13) is located between adjacent bent portions (9, 11) and is attached to the flexible member (17) between these bent portions (9, 11) to suppress bending of the flexible member (17) in the axial direction.

[0012] The intermediate portion 13 may have various configurations, and may be an annular member that is axially inserted through the flexible member 17. In this case, the inner periphery of the intermediate portion 13 is attached to the flexible member 17.

[0013] The multiple bent portions (9, 11) may each include an outer member (19, 21) surrounding the flexible member (17) and having elasticity.

[0014] In this case, the outer members (19, 21) of adjacent bent portions (9, 11) may be configured such that their ends, which face each other across the intermediate portion (13) in the axial direction, are attached to both axial sides of the intermediate portion (13), respectively.

[0015] The flexible member 17 may have various configurations, but may have an inner coil portion 27 and an outer coil portion 29. In this case, the corresponding winding portions 27a of the inner coil portion 27 fit into the gaps 29b between adjacent winding portions 29a of the outer coil portion 29. EXAMPLES

[0016] [Bending structure] Fig. 1 is a front view showing a bent structure according to a first embodiment of the present invention. Fig. 2 is a schematic vertical cross-sectional view of the bent structure of Fig. 1 when not bent. Fig. 3 is an enlarged view of a main part of Fig. 2. Fig. 4 is a schematic vertical cross-sectional view of the bent structure of Fig. 1 when bent.

[0017] The bending structure 1 is applied to a joint function part of various devices for medical and industrial use, such as a manipulator, a robot, and an actuator. The joint function part is an apparatus, mechanism, device, etc. that has a function as a bending / extending joint.

[0018] The bending structure 1 of this embodiment is a multi-joint structure, and includes a base portion 3, a movable portion 5, and a multi-joint portion .

[0019] The base 3 is a columnar body, for example a cylindrical body, made of metal, resin, etc. This base 3 is attached to the end of a shaft of a manipulator, etc. Note that the base 3 is not limited to a columnar body, and may have an appropriate shape depending on the device to which the bending structure 1 is applied.

[0020] The movable part 5 is made of a columnar body, for example, a cylindrical body, like the base part 3. An end effector or the like according to the equipment to which the bending structure 1 is applied is attached to the movable part 5. Note that the movable part 5 is also made to have an appropriate shape according to the equipment to which the bending structure 1 is applied, and is not limited to a columnar body.

[0021] The movable portion 5 is supported by the base portion 3 via an articulated portion 7 so as to be displaceable in the axial direction.

[0022] [Articulated parts] The articulated portion 7 includes a first bent portion 9, a second bent portion 11, and an intermediate portion 13.

[0023] The first bending portion 9 and the second bending portion 11 are portions that can bend and extend as joints. The first bending portion 9 and the second bending portion 11 have elasticity that allows them to bend and extend elastically, but they can also function without having elasticity. In this embodiment, the bending structure 1 is configured to have two adjacent bending portions 9 and 11, but it may have three or more bending portions.

[0024] Bending and stretching refer to bending and stretching in a direction along the axis of the bending structure 1 (hereinafter referred to as the axial direction). Note that the axial direction does not need to be strictly along the axis of the bending structure 1.

[0025] The first bent portion 9 is a bent portion on one axial side of the intermediate portion 13, for example, on the movable portion 5 side, and the second bent portion 11 is a bent portion on the other axial side of the intermediate portion 13, for example, on the base portion 3 side. When there are three or more bent portions, of the adjacent bent portions, the first bent portion 9 is on one axial side of the intermediate portion 13, and the second bent portion 11 is on the other axial side. The number of intermediate portions 13 is one less than the number of bent portions 9, 11.

[0026] The first bending portion 9 is bent by being operated by a wire 15 connected to the movable portion 5. The wire 15 is inserted through the first bending portion 9, the intermediate portion 13, and the second bending portion 11 to reach the base portion 3 side, and enables the first bending portion 9 to be bent by being pulled on the base portion 3 side.

[0027] The second bending portion 11 is bent by being operated by a wire (not shown) in the same manner as the first bending portion 9. The wire is attached to the intermediate portion 13, passes through the second bending portion 11 and reaches the base portion 3 side, and enables the second bending portion 11 to be bent by being pulled on the base portion 3 side.

[0028] The first bent portion 9 and the second bent portion 11 may be bent using an appropriate cord-like body such as a single wire, a twisted wire, a piano wire, a multi-joint rod, a chain, a string, a thread, or a rope, other than a wire.

[0029] The first bent portion 9 and the second bent portion 11 are set to have the same axial length. However, the axial lengths of the first bent portion 9 and the second bent portion 11 may be made different by changing the axial position of the intermediate portion 13 (see FIG. 5).

[0030] The first bent portion 9 and the second bent portion 11 are each composed of a flexible member 17 and outer members 19 and 21.

[0031] The flexible member 17 is disposed along the axial direction and functions as a core material that suppresses axial compression of the first bent portion 9 and the second bent portion 11. The flexible member 17 is formed in a cylindrical shape as a whole, and defines an insertion hole 17a on the inside. The insertion hole 17a is for inserting a flexible member such as a wire or an air tube. The flexible member 17 may be configured not to define the insertion hole 17a depending on the device to which the bent structure 1 is applied.

[0032] The flexible member 17 of this embodiment is integrally formed in the axial direction from the first bent portion 9 to the second bent portion 11. The flexible member 17 of this embodiment is continuous without interruption from the first bent portion 9 to the second bent portion 11, and extends from the base portion 3 to the movable portion 5. This flexible member 17 is partitioned into a first portion 23 and a second portion 25 by attaching an intermediate portion 13 as described below. The first portion 23 and the second portion 25 correspond to the first bent portion 9 and the second bent portion 11, respectively.

[0033] In addition, the flexible member 17 may be formed separately between the first bent portion 9 and the second bent portion 11, and may be substantially integrally configured by positioning the separated end portion within the axial range of the intermediate portion 13.

[0034] In this embodiment, the flexible member 17 has a double coil structure, and includes an inner coil portion 27 and an outer coil portion 29. The flexible member 17 may have various configurations, and may be configured by a single tightly coiled coil spring, a flexible cylinder, or the like.

[0035] The inner coil portion 27 and the outer coil portion 29 are each made of metal, resin, or the like, and are flexible coil springs that can be bent and extended in the axial direction. The inner coil portion 27 has a smaller center diameter than the outer coil portion 29, and is screwed into the outer coil portion 29. As a result, the corresponding winding portion 27a of the inner coil portion 27 fits into the gap 29b between adjacent winding portions 29a of the outer coil portion 29.

[0036] This dual coil shaped flexible member 17 is bendable and extendable in the axial direction as a whole, and the length of the axial center is approximately constant before, during and after bending.

[0037] That is, when the flexible member 17 is bent by an external force, the inside of the bend contracts and the outside of the bend expands, so that the length of the axis does not change compared to when the flexible member 17 is not bent. Therefore, the path length of the member passing through the insertion hole 17a can be made constant.

[0038] Moreover, the flexible member 17 is configured such that the corresponding winding portions 27a of the inner coil portion 27 fit into the gaps 29b between the adjacent winding portions 29a of the outer coil portion 29, thereby suppressing compression in the axial direction.

[0039] The outer members 19 and 21 are elastic members provided on the first bent portion 9 and the second bent portion 11, respectively. These outer members 19 and 21 impart elasticity to the first bent portion 9 and the second bent portion 11, allowing them to restore (extend) after bending. Therefore, the flexible member 17 can be set to have low elasticity and high flexibility. It is also possible to omit the outer members 19 and 21. In this case, it is sufficient that the flexible member 17 itself has elasticity that allows it to restore after bending.

[0040] These outer members 19, 21 are annular and surround the flexible member 17, and are attached between the movable portion 5 and the intermediate portion 13, and between the intermediate portion 13 and the base portion 3, respectively. By this attachment, the outer members 19, 21 are positioned with respect to the flexible member 17. Note that in this embodiment, the outer members 19, 21 are positioned concentrically with the flexible member 17, but they do not have to be concentric with the flexible member 17.

[0041] In addition, the outer members 19 and 21 may simply be interposed between the movable portion 5 and the intermediate portion 13 and between the intermediate portion 13 and the base portion 3.

[0042] The outer members 19, 21 of this embodiment are configured by stacking a plurality of wave washers 31 made of metal, resin, etc. in the axial direction. These outer members 19, 21 are bendable by elastic deformation of the wave washers 31.

[0043] The outer members 19, 21 are not limited to being formed by stacking wave washers 31, and may be formed of other materials. For example, the outer members 19, 21 may be formed of a coil spring, a bellows made of a tube having a corrugated cross section, a double coil similar to the flexible member 17, or the like.

[0044] The intermediate portion 13 is attached to the flexible member 17 between the adjacent first bending portion 9 and second bending portion 11 to suppress bending of the flexible member 17 in the axial direction. In this embodiment, suppressing bending means preventing bending. However, suppressing bending may be such that the intermediate portion 13 allows slight bending of the flexible member 17 to the extent that it does not affect the operation of the first bending portion 9 and the second bending portion 11.

[0045] The intermediate portion 13 in this embodiment is an annular member through which the flexible member 17 is inserted in the axial direction. The intermediate portion 13, which is an annular member, is formed in a plate shape having an insertion hole 13a for the flexible member 17 in the center.

[0046] However, the shape of the intermediate portion 13 is arbitrary, and in addition to a plate shape having the insertion hole 13a, it may be a cylinder shape, a member such as a plurality of separate plate-like bodies attached in a ring shape to the flexible member 17, or an annular member having a notch in a part in the circumferential direction. Also, although the planar shape of the intermediate portion 13 is circular in this embodiment, it may be formed into other geometric shapes.

[0047] The intermediate portion 13 has its inner periphery attached to the flexible member 17 with the flexible member 17 inserted therethrough. The inner periphery of the intermediate portion 13 can be attached to the flexible member 17 over a part or the entirety of the inner periphery of the intermediate portion 13. The attachment method may be welding, bonding, caulking, or the like, as appropriate. In this embodiment, the attachment position of the intermediate portion 13 is the axial center of the articulated portion 7. However, the intermediate portion 13 may be attached displaced in the axial direction from the center.

[0048] 5 and 6 are vertical cross-sectional views of the bending structure 1 according to the modified example when unbent and when bent. Note that Fig. 6 shows a state in which only the first bending portion 9 is bent.

[0049] 5 and 6, the intermediate portion 13 is displaced toward the base portion 3 with respect to the axial center of the articulated portion 7 and attached to the flexible member 17. In this modification, the characteristics can be changed by changing the lengths of the first bent portion 9 and the second bent portion 11. For example, the bending start position of the first bent portion 9, the bending angle and bending radius of the first bent portion 9 and the second bent portion 11, etc. can be changed.

[0050] 5, intermediate portion 13 may be displaced toward movable portion 5 and attached to flexible member 17. By changing the attachment position of intermediate portion 13 in this manner, the characteristics can be easily adjusted.

[0051] Also, the intermediate portion 13 can be slidably fitted and attached to the flexible member 17. In this case, by adjusting the position of the intermediate portion 13, the lengths of the adjacent first bent portion 9 and second bent portion 11 can be changed to change the characteristics. However, the first bent portion 9 and second bent portion 11 need to expand and contract in the axial direction according to the adjustment of the position of the intermediate portion 13.

[0052] Ends of outer members 19, 21 of the first bent portion 9 and the second bent portion 11 are attached to both axial sides of the intermediate portion 13. In this embodiment, this attachment is performed by fastening such as welding or bonding, but the ends of the outer members 19, 21 may simply be brought into contact with the intermediate portion 13 without being fastened thereto.

[0053] As a result, the intermediate portion 13 is held by the outer members 19 and 21 from both sides in the axial direction.

[0054] The inner and outer diameters of the intermediate portion 13 are equal to the inner and outer diameters of the outer members 19, 21. Therefore, the intermediate portion 13 is prevented from protruding in the radial direction relative to the outer members 19, 21, and is prevented from being subjected to inadvertent external force.

[0055] The inner and outer diameters of the intermediate portion 13 may be set larger or smaller than the inner and outer diameters of the outer members 19, 21. However, the inner diameter of the intermediate portion 13 must be within a range that allows attachment to the flexible member 17.

[0056] The axial dimension of the intermediate portion 13 is set within a range that can suppress bending of the flexible member 17. Therefore, in the bending structure 1, the axial dimension of the intermediate portion 13 can be minimized as long as bending of the flexible member 17 can be suppressed. Note that the axial dimension of the intermediate portion 13 may be set to the minimum size that can fix the wire that operates the second bending portion 11.

[0057] In this embodiment, the axial dimension of the intermediate portion 13 is smaller than the radial dimension (difference between the inner and outer diameters) of the intermediate portion 13. In relation to the flexible member 17, the axial dimension of the intermediate portion 13 is approximately three turns of the outer coil portion 29 of the flexible member 17.

[0058] However, the axial dimension of the intermediate portion 13 can be appropriately set according to the flexibility of the flexible member 17, and may be made smaller or larger. In this case, the flexible member 17 can be configured so that the number of winding portions 29a attached to the intermediate portion 13 can be adjusted according to the flexibility of the flexible member 17.

[0059] The material of the intermediate portion 13 may be appropriately selected from metal, resin, etc., depending on the material of the flexible member 17 and the characteristics required for the bent structure 1, etc.

[0060] [Operation] In the bending structure 1 of this embodiment, the operator can bend the first bending portion 9 and the second bending portion 11 in any of the 360-degree directions by pulling one or more of the wires 15 and wires (not shown).

[0061] When the first bent portion 9 bends, the wave washers 31 of the outer members 19 and 21 are compressed on the inner side of the bend relative to the neutral axis and expanded on the outer side of the bend.

[0062] At the same time, the first portion 23 of the flexible member 17 contracts on the inside of the bend and expands on the outside of the bend. In this embodiment, the gap 29b of the outer coil portion 29 becomes smaller on the inside of the bend, displacing the inner coil portion 27 toward the outside of the bend, and the gap 29b of the outer coil portion 29 becomes larger on the outside of the bend, allowing the inner coil portion 27 to displace.

[0063] At this time, the intermediate portion 13 suppresses bending of the flexible member 17 at its attachment portion. The intermediate portion 13 defines a first portion 23 of the flexible member 17 on the movable portion 5 side, and an outer member 19 of the first bending portion 9 is attached to the movable portion 5 side.

[0064] For this reason, the intermediate portion 13 functions as a base portion of the first bent portion 9. Therefore, the first bent portion 9 can be bent as a whole with respect to the intermediate portion 13, and the movable portion 5 can be oriented in a desired direction.

[0065] Similarly, when the second bent portion 11 is bent, the intermediate portion 13 functions as a movable portion of the second bent portion 11, so that the second bent portion 11 is bent as a whole relative to the base portion 3, and the intermediate portion 13 can be oriented in the desired direction.

[0066] In this manner, in the bending structure 1 of this embodiment, the first bending portion 9 and the second bending portion 11 are bent, so that the movable portion 5 can be oriented in a desired direction.

[0067] [Effects of Example 1] As described above, the bent structure 1 of this embodiment comprises a plurality of first bent portions 9 and second bent portions 11 that are elastically bendable in the axial direction, and an intermediate portion 13 located between adjacent first bent portions 9 and second bent portions 11. The first bent portions 9 and second bent portions 11 comprise a flexible member 17 that is integrated in the axial direction. The intermediate portion 13 is attached to the flexible member 17 between adjacent first bent portions 9 and second bent portions 11 to suppress bending in the axial direction.

[0068] Therefore, the axial dimension of the intermediate portion 13 can be reduced as long as bending of the flexible member 17 can be suppressed between the adjacent first bending portion 9 and second bending portion 11. As a result, the bent structure 1 can have a maneuverable structure by reducing the portion that does not contribute to bending.

[0069] The intermediate portion 13 is an annular member into which the flexible member 17 is inserted in the axial direction, and its inner periphery is attached to the flexible member 17 .

[0070] Therefore, by inserting the flexible member 17 through the intermediate portion 13 and attaching it, bending of the flexible member 17 can be easily and reliably suppressed with a simple structure.

[0071] Since the intermediate portion 13 is fixed to the flexible member 17, it is possible to more reliably suppress bending of the flexible member 17. Even when the intermediate portion 13 is attached to the flexible member 17 by being slidably fitted thereto, it is possible to suppress bending of the flexible member 17.

[0072] The first bent portion 9 and the second bent portion 11 each include an outer member 19, 21 that surrounds the flexible member 17 and has elasticity.

[0073] Therefore, in this embodiment, elasticity can be imparted to the first bent portion 9 and the second bent portion 11 by the outer members 19 and 21, and the elasticity of the flexible member 17 can be reduced.

[0074] The outer members 19, 21 of the adjacent first bent portion 9 and second bent portion 11 are attached at their ends, which face each other with the intermediate portion 13 therebetween, to both sides of the intermediate portion 13 in the axial direction.

[0075] Therefore, the intermediate portion 13 can function both as a member that suppresses bending of the flexible member 17 and as a support member for the outer members 19 and 21. Therefore, in the bent structure 1, the portions that do not contribute to bending can be made smaller, thereby achieving a more maneuverable structure.

[0076] The flexible member 17 has an inner coil portion 27 and an outer coil portion 29, and the corresponding winding portions 27a of the inner coil portion 27 fit into the gaps 29b between adjacent winding portions 29a of the outer coil portion 29.

[0077] Therefore, the flexible member 17 can suppress axial compression of the first bent portion 9 and the second bent portion 11, and can keep constant the path length of the member passing through the inside. Also, the flexible member 17 can easily adjust the suppression of bending by adjusting the number of winding portions 29a attached to the intermediate portion 13. [Explanation of symbols]

[0078] 1 Bent structure 9 1st bending part 11 Second bending part 13 Middle section 17 Flexible member 19,21 Outer member 27 Inner coil section 27a winding part 29 Outer coil section 29a Volume 29b Gap 31 Wave Washer

Claims

1. Bending portions adjacent to each other in the axial direction, the bending portions being elastically bendable in the axial direction; an intermediate portion located between adjacent bent portions; and a cord-like body for operation, the adjacent bends include integral flexible members in the axial direction; the intermediate portion is attached to the flexible member between the adjacent bent portions to suppress bending of the flexible member in the axial direction; The cord-like body is attached to the middle portion. bending structure.

2. 2. The bent structure according to claim 1, The intermediate portion is an annular member that is inserted through the flexible member in the axial direction, and an inner periphery of the intermediate portion is attached to the flexible member. bending structure.

3. The bent structure according to claim 1 or 2, The intermediate portion is fixed to the flexible member. bending structure.

4. The bent structure according to any one of claims 1 to 3, Each of the adjacent bent portions has an outer member that surrounds the flexible member and has elasticity. bending structure.

5. The bent structure according to claim 4, The outer members of the adjacent bent portions are attached to both sides of the intermediate portion in the axial direction at end portions opposed to each other with the intermediate portion therebetween in the axial direction, bending structure.

6. The bent structure according to any one of claims 1 to 5, The flexible member has an inner coil portion and an outer coil portion, and a corresponding winding portion of the inner coil portion is fitted into a gap between adjacent winding portions of the outer coil portion. bending structure.

7. A bend portion adjacent to the axial direction, the bend portion being elastically bendable in the axial direction; an intermediate portion located between adjacent bent portions; the adjacent bends include integral flexible members in the axial direction; the flexible member comprises a coil having a plurality of turns; the intermediate portion is attached to the flexible member between the adjacent bent portions to suppress bending of the flexible member in the axial direction; setting the characteristics of the flexible member according to the number of turns of the flexible member attached to the intermediate portion; bending structure.

Images