Torque limiting structure and pipe fixing device equipped therewith

Abstract

To provide a torque limit structure capable of applying necessary and sufficient amount of torque, and reducing a risk that excessive rotational torque is applied to generate engaging after idling a tip end portion.SOLUTION: A torque limit structure when the rotational torque of an operation rod 100 having a tip end portion 108 is transmitted to a pinion member 16 provided with a tip end portion insertion hole 44 in which the tip end portion 108 can be inserted is configured as follows. A number of corners of cross-sectional inner side shapes in the tip end portion insertion hole 44 is made to be twice a number of corners of cross-sectional outer side shapes at the tip end portion 108. A plurality of sides configuring an angle shape in the cross-sectional inner side shapes are configured by biting sides A in which a corner Z at the tip end portion 108 bites, and non-biting sides B provided with a recessed place 50 so as to prevent the biting of the corner Z. The biting sides A and the non-biting sides B are alternately formed in a circumferential direction of the cross-sectional inner side shapes.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a torque limit structure (slip shaft coupling) used for pipe fixtures and the like.

Background Art

[0002] Conventionally, tools such as pipe fixtures (hereinafter referred to as "pipe fixtures and the like") have been configured to insert the tip of an operating rod into a pinion member disposed at the lower end thereof and rotate the operating rod to rotate the pinion member and raise and lower a pipe fixing member, thereby fixing a pipe or the like at a predetermined position with the pipe fixing member.

[0003] For example, as shown in FIG. 13, a hole 2 having a hexagonal cross section is formed in a pinion member 1, and the tip 3 of an operating rod is formed in a hexagonal bar shape having a hexagonal cross section. In this way, the rotational force of the tip 3 of the operating rod is transmitted to the pinion member 1.

[0004] Specifically, by appropriately setting the size of the hexagon in the hole 2 of the pinion member 1 and the size of the hexagon in the tip 3 of the operating rod, as shown in FIG. 14, the corner 4 of the tip 3 is made to bite into the pinion member 1 to apply a rotational torque of the tip ३ of the operating rod to the pinion member 1, and when the torque becomes excessive, the tip 3 can be rotated freely with respect to the pinion member 1 (it becomes a position rotated 60° from FIG. 13, and the state where the corner 4 of the tip 3 bites into the pinion member 1 is released).

[0005] This has made it possible to avoid applying excessive torque to the pinion member 1 and prevent excessive tightening of a pipe or the like by a pipe fixture or the like (torque limit).

[0006] In addition to the examples described above, another example of such a torque limit structure is disclosed in Patent Document 1, in which a pair of elastic wires are stretched across the opening of a hole (torque transmission destination) in a pinion member, and the tip of an operating rod (torque transmission source) inserted into a hole in a socket is sandwiched between these elastic wires.

[0007] When the rotational torque at the tip of the operating rod is less than the clamping force at the tip by the pair of elastic wires, the pinion member rotates along with the rotation of the tip. When the rotational torque at the tip of the operating rod becomes greater than the clamping force at the tip by the pair of elastic wires, the tip rotates freely between the elastic wires. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2006-170248 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] However, conventional torque limiting structures had problems. For example, in the case where a hexagonal hole is drilled in the pinion member 1 and the tip 3 of the operating rod is hexagonal, when the rotational torque of the tip 3 of the operating rod becomes excessive relative to the pinion member 1, the tip 3 spins freely relative to the pinion member 1, and the hexagonal corner 4 of the tip 3 can get stuck in the next edge of the pinion member 1 due to excessive force (position rotated 60° from Figure 14).

[0010] If the tip 3 becomes jammed into the pinion member 1 in this way, the operating rod will not be able to detach from the pinion member 1. Therefore, it is necessary to apply excessive rotational torque to the operating rod again to make the tip spin freely, or to rotate the operating rod in the reverse direction. However, in each case, there is a risk of jamming again or of the tightening of the pinion member 1 becoming loose.

[0011] Furthermore, when controlling rotational torque with a pair of elastic wires, slippage occurs at smaller torque values ​​compared to the case of a hexagonal hole. In contrast, when trying to increase the specified torque value, it becomes difficult to insert the tip of the operating rod between the pair of elastic wires.

[0012] This invention has been made in view of such problems and needs, and its objective is to provide a torque limit structure that can apply a sufficiently large torque and reduce the risk of jamming occurring after the tip spins freely due to excessive rotational torque, and a pipe fixing device equipped therewith. [Means for solving the problem]

[0013] According to one aspect of the present invention, A torque limiting structure for when the rotational torque of an operating rod having a tip is transmitted to a pinion member having a tip insertion hole into which the tip can be inserted, The tip portion has an outer cross-sectional shape that is angular. The aforementioned tip insertion hole has an inner cross-sectional shape that is angular. The number of angles of the inner cross-sectional shape in the tip insertion hole is twice the number of angles of the outer cross-sectional shape in the tip. The plurality of sides that constitute the angular shape in the inner cross-sectional shape of the tip insertion hole are, The corner of the outer cross-sectional shape at the tip portion bites into the biting edge, The tip portion has a non-inserting edge with a recess formed so that the corner of the outer cross-sectional shape does not dig in, The indented edges and the non-indented edges are formed alternately in the circumferential direction of the inner cross-sectional shape. A torque limiting structure is provided.

[0014] Preferably, The outer cross-sectional shape of the tip portion is triangular. The inner cross-sectional shape of the tip insertion hole is hexagonal.

[0015] Preferably, the outer cross-sectional shape of the tip portion is a quadrilateral, and the inner cross-sectional shape in the tip insertion hole is an octagon.

[0016] According to another aspect of the present invention, a pipe fixture having the pinion member used in the torque limit structure described above and operated by the operating rod is provided.

Effect of the Invention

[0017] According to the present invention, the number of corners of the inner cross-sectional shape in the tip insertion hole formed in the pinion member is twice the number of corners of the outer cross-sectional shape at the tip of the operating rod, and a plurality of sides constituting the angular shape in the inner cross-sectional shape of the tip insertion hole are formed by alternately arranging biting sides into which the corners of the outer cross-sectional shape at the tip bite and non-biting sides in which recesses are formed so as not to bite.

[0018] Thereby, the rotational torque of the operating rod is transmitted to the pinion member in a state where the corners of the outer cross-sectional shape at the tip of the operating rod bite into the biting pieces in the inner cross-sectional shape of the tip insertion hole of the pinion member. Then, when the rotational torque from the operating rod becomes excessive and the tip rotates freely, the side in the inner cross-sectional shape of the tip insertion hole that the corner next approaches is a non-biting side, so that the risk that the corner undesirably bites into the side in the inner cross-sectional shape can be reduced.

[0019] As a result, it is possible to provide a torque limit structure that can apply a necessary and sufficient amount of torque and reduce the risk of unwanted meshing after applying excessive rotational torque and causing the tip to rotate freely.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view showing a pipe fixture 10 to which the present invention is applied. [Figure 2] It is a cross-sectional view showing a pipe fixture 10 to which the present invention is applied. [Figure 3] Front view showing the pinion member 16 to which the present invention is applied. [Figure 4] Cross-sectional view showing the pinion member 16 to which the present invention is applied. [Figure 5] View showing the inner shape of the cross-section of the tip insertion hole 44 formed in the pinion member 16. [Figure 6] Front view showing the operating rod 100 to which the present invention is applied. [Figure 7] View showing the outer shape of the cross-section of the tip portion 108 formed in the operating portion 104. [Figure 8] View showing a state where the corner Z of the outer shape of the cross-section at the tip portion 108 bites into the biting side A of the inner shape of the cross-section of the tip insertion hole 44, and the rotational torque of the operating rod 100 is transmitted to the pinion member 16. [Figure 9] View showing a state where the corner Z of the outer shape of the cross-section at the tip portion 108 is at the position of the non-biting side B of the inner shape of the cross-section of the tip insertion hole 44, and an undesired meshing can be avoided. [Figure 10] In the first modification, it is a view showing a state where the corner Z of the outer shape of the cross-section at the tip portion 108 bites into the biting side A of the inner shape of the cross-section of the tip insertion hole 44, and the rotational torque of the operating rod 100 is transmitted to the pinion member 16. [Figure 11] In the first modification, it is a view showing a state where the corner Z of the outer shape of the cross-section at the tip portion 108 is at the position of the non-biting side B of the inner shape of the cross-section of the tip insertion hole 44, and an undesired meshing can be avoided. [Figure 12] Perspective view showing an example (wire binding tool) to which the present invention is applied. [Figure 13] View showing an example of a conventional torque limit structure. [Figure 14] View showing an example of a conventional torque limit structure.

Embodiments for Carrying Out the Invention

[0021] (Configuration of the pipe fixing tool 10) As shown in Figures 1 and 2, the pipe fixing device 10 according to this embodiment generally comprises a main body member 12, a pipe fixing arm 14, and a pinion member 16.

[0022] The main body member 12 has a roughly cylindrical pinion member fitting portion 18 positioned in the center, and a first arm member sliding hole 20 and a second arm member sliding hole 22 are formed on both sides of this pinion member fitting portion 18, through which the pipe fixing arm 14 slides.

[0023] A projection fitting hole 24 is formed approximately in the center of the pinion member fitting portion 18, into which the rotational center projection 46 (described later) of the pinion member 16 is fitted.

[0024] The pipe fixing arm 14 has a main body portion 26 that is roughly "J" shaped, and a pipe holding portion 28 that protrudes from the bent portion 34 of the main body portion 26 in a direction perpendicular to the bending direction of the main body portion 26.

[0025] The main body 26 is formed in a roughly "J" shape by a long section 30, a short section 32 extending parallel to the long section 30, and a curved section 34 spanning between the end of the long section 30 (upper end in the figure) and the end of the short section 32 (upper end in the figure).

[0026] Rack gears 36 are formed on the inner sides of the long section 30 and the short section 32 of the main body 26, respectively.

[0027] The long section 30 is always fitted into the first arm member sliding hole 20 in the main body member 12. On the other hand, the short section 32 is spaced away from the second arm member sliding hole 22 when the distance between the main body member 12 and the curved section 34 is long, and becomes fitted into the second arm member sliding hole 22 when the distance between the main body member 12 and the curved section 34 becomes shorter. This allows the material to be fixed, such as a pipe, to be placed between the long section 30 and the short section 32 when the distance between the main body member 12 and the curved section 34 is relatively long and the short section 32 is spaced away from the second arm member sliding hole 22, and finally fixed by the main body member 12 and the pipe fixing arm 14.

[0028] In this embodiment, the main body 26 and the pipe holding portion 28 are fixed separately, but the main body 26 and the pipe holding portion 28 may be formed integrally. Alternatively, the pipe holding portion 28 may be omitted, and the pipe fixing arm 14 may be constructed using only the main body 26.

[0029] As described above, the pinion member 16 is a substantially cylindrical member that is fitted into the pinion member fitting portion 18 of the main body member 12. As shown in Figures 3 and 4, it has a pinion member main body portion 40, a pinion gear 42 formed on the outer peripheral surface of the pinion member main body portion 40, a tip insertion hole 44 formed from one end face (lower end face in the figure) of the pinion member main body portion 40, and a rotation center projection 46 formed to protrude from the other end face (upper end face in the figure) of the pinion member main body portion 40.

[0030] The pinion gear 42 is configured to constantly mesh with a rack gear 36 formed on the long portion 30 of the pipe fixing arm 14, which is fitted into the sliding hole 20 of the first arm member, when the pinion member 16 is fitted into the pinion member fitting portion 18. Similarly, the pinion gear 42 also meshes with a rack gear 36 formed on the short portion 32 of the pipe fixing arm 14, which is fitted into the sliding hole 22 of the second arm member. Alternatively, the rack gear 36 may be omitted from the short portion 32, so that the short portion 32 does not mesh with the pinion gear 42.

[0031] The tip insertion hole 44 allows the tip 108 of the operating rod 100, which will be described later, to be inserted, and the rotational torque of the operating rod 100 is transmitted to the pinion member 16.

[0032] Here, the shape of the tip insertion hole 44 will be described in detail. As shown in Figure 5, the inner cross-sectional shape of the tip insertion hole 44 according to this embodiment is set to a hexagon composed of six sides.

[0033] The six sides that make up the inner cross-sectional shape of the tip insertion hole 44 are formed alternately in the circumferential direction of the inner cross-sectional shape, with a cutting edge A and a non-cutting edge B. The cutting edge A is the side into which the corner Z of the outer cross-sectional shape of the tip 108 cuts in, and as an example, in this embodiment, it is formed linearly in the cross-section. The non-cutting edge B has a recess 50 formed so that the corner Z of the outer cross-sectional shape of the tip 108 does not cut into it.

[0034] The shape of the recess 50 is not particularly limited as long as the corner Z of the outer cross-sectional shape at the tip portion 108 does not intrude. For example, in this embodiment, the recess has a smoothly concave shape in cross-section.

[0035] Returning to Figures 3 and 4, the rotational center projection 46 is, as described above, a portion that is rotatably fitted into the projection fitting hole 24 formed approximately in the center of the pinion member fitting portion 18. By fitting the rotational center projection 46 into this projection fitting hole 24, the pinion member 16 becomes rotatable about the rotation axis X of the pinion gear 42 within the pinion member fitting portion 18 of the main body member 12.

[0036] (Configuration of the operating rod 100) Next, the operating rod 100 used to fix the pipe fixing device 10 described above to a pipe or the like will be explained. As shown in Figure 6, the operating rod 100 has an operating rod body 102 set to a predetermined length and an operating part 104 formed at the tip of the operating rod body 102. The operating rod body 102 and the operating part 104 may be formed integrally with each other, or they may be constructed as separate parts so that the operating part 104 can be attached to and detached from the operating rod body 102 as needed. In this embodiment, an operating part 104 that can be attached to and detached from the operating rod body 102 will be explained as an example.

[0037] The operating section 104 is formed in a roughly round rod shape and is integrally formed with the operating section body 106, the tip 108, and the operating rod body connection 110.

[0038] The tip portion 108 is a prismatically formed portion at one end (the upper end in the figure) of the operating unit body portion 106. As shown in Figure 7, the outer cross-sectional shape of this tip portion 108 is angular, and in this embodiment, it is formed in a substantially triangular shape with three angles Z.

[0039] Returning to Figure 6, the operating rod body connection portion 110 is a cylindrical portion formed at the other end (lower end in the figure) of the operating section body portion 106, with a diameter slightly larger than that of the operating section body portion 106, allowing the tip of the operating rod body 102 to be inserted from the other end of the operating section 104.

[0040] The "torque limit structure" is formed by the pinion member 16 in the pipe fixing device 10 and the tip portion 108 of the operating rod 100, as described above.

[0041] (Features of the torque limit structure) According to the torque limit structure of this embodiment, the number of angles (=hexagons) of the inner cross-sectional shape of the tip insertion hole 44 formed in the pinion member 16 is twice the number of angles (=triangles) of the outer cross-sectional shape of the tip portion 108 of the operating rod 100, and the multiple sides constituting the angular shape of the inner cross-sectional shape of the tip insertion hole 44 are formed by alternating insertion sides A into which the corner Z of the outer cross-sectional shape of the tip portion 108 bites, and non-insertion sides B into which a recess 50 is formed so that it does not bite.

[0042] As a result, the rotational torque of the operating rod 100 is transmitted to the pinion member 16 with the corner Z of the cross-sectional outer shape of the tip portion 108 of the operating rod 100 biting into the biting edge A of the cross-sectional inner shape of the tip insertion hole 44 of the pinion member 16 (see Figure 8). Furthermore, when the rotational torque from the operating rod 100 becomes excessive and the tip portion 108 spins freely, the next edge of the cross-sectional inner shape of the tip insertion hole 44 that the corner Z approaches is a non-biting edge B, thus reducing the risk of the corner Z unintentionally biting into an edge of the cross-sectional inner shape (see Figure 9).

[0043] As a result, we were able to provide a torque limit structure that can apply a sufficiently large torque and reduce the risk of unwanted jamming occurring after the tip 108 spins freely due to excessive rotational torque.

[0044] (Variation 1) In the torque limit structure according to the embodiment described above, the case in which the number of angles of the inner cross-sectional shape of the tip insertion hole 44 formed in the pinion member 16 is hexagonal and the number of angles of the outer cross-sectional shape of the tip portion 108 of the operating rod 100 is triangular was described. However, the number of angles is not limited to these, and for example, as shown in Figures 10 and 11, the number of angles of the inner cross-sectional shape of the tip insertion hole 44 formed in the pinion member 16 may be octagonal and the number of angles of the outer cross-sectional shape of the tip portion 108 of the operating rod 100 may be square.

[0045] (Modification 2) In the embodiments described above, an example of applying the torque limit structure to a pipe fixing device 10 was explained, but the torque limit structure may also be applied to applications other than the pipe fixing device 10. For example, it can be used in wire binding devices for bundling multiple wires (see Figure 12), bird control devices to prevent birds from perching on wires, insulating covers to cover wires, short-circuit grounding tools for temporarily grounding wires during transformer replacement work, or insulation penetration clamps for connecting wires to contact blades without stripping the insulation from live overhead insulated wires.

[0046] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0047] 10... Pipe fixing device, 12... Main body member, 14... Pipe fixing arm, 16... Pinion member, 18... Pinion member insertion part, 20... First arm member sliding hole, 22... Second arm member sliding hole, 24... Protrusion insertion hole, 26... Main body part, 28... Pipe holding part, 30... Long part, 32... Short part, 34... Bent part, 36... Rack gear, 40... Pinion member main body part, 42... Pinion gear, 44... Tip insertion hole, 46... Rotation center projection, 50... Recess (on non-inserting side B) 100...Operating rod, 102...Operating rod body, 104...Operating section, 106...Operating section body, 108...Tip, 110...Operating rod body connection section X…rotation axis (of the pinion gear 42), A…engaged side, B…non-engaged side, Z…angle (in the outer cross-sectional shape of the tip portion 108)

Claims

1. A torque limiting structure for when the rotational torque of an operating rod having a tip is transmitted to a pinion member having a tip insertion hole into which the tip can be inserted, The tip portion has an outer cross-sectional shape that is angular. The aforementioned tip insertion hole has an inner cross-sectional shape that is angular. The number of angles of the inner cross-sectional shape in the tip insertion hole is twice the number of angles of the outer cross-sectional shape in the tip. The plurality of sides that constitute the angular shape in the inner cross-sectional shape of the tip insertion hole are, The corner of the outer cross-sectional shape at the tip portion bites into the biting edge, The tip portion has a non-inserting edge with a recess formed so that the corner of the outer cross-sectional shape does not dig in, The indented edges and the non-indented edges are formed alternately in the circumferential direction of the inner cross-sectional shape. Torque limiting structure.

2. The outer cross-sectional shape of the tip portion is triangular. The inner cross-sectional shape of the tip insertion hole is hexagonal. Torque limiting structure according to claim 1.

3. The outer cross-sectional shape of the tip portion is rectangular. The inner cross-sectional shape of the tip insertion hole is octagonal. Torque limiting structure according to claim 1.

4. A pipe fixing device having the pinion member used in a torque limiting structure according to any one of claims 1 to 3, and operated by the operating rod.

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