WO2006013724A1

WO2006013724A1 - Nut member with multi-pitch screw and method of manufacturing the same

Info

Publication number: WO2006013724A1
Application number: PCT/JP2005/013301
Authority: WO
Inventors: Hiroshi Fujii; Naoki Sase; Kenichi Katayama; Yoshinori Moriguchi
Original assignee: Nagoya Industrial Science Research Institute
Priority date: 2004-08-06
Filing date: 2005-07-20
Publication date: 2006-02-09
Also published as: JP4530758B2; JP2006046546A

Abstract

[PROBLEMS] To provide a method of manufacturing a nut member having a practicable multi-pitch screw. [MEANS FOR SOLVING PROBLEMS] A linear member (10a) comprises a ridge-shaped part (101) provided by linearly expanding equal lead angle thread and a ridge-shaped part (102) provided by linearly expanding a multi-pitch thread. The linear member is wound in a coiled shape to form a spiral coil insert body (10) having an equal lead angle male screw part (14) on the outer peripheral surface thereof and a multi-pitch male screw part (16) on the inner peripheral surface thereof. Then, the coil insert body (10) is threaded to a nut (21) having, on the inner periphery thereof, a female screw part (14) with the equal lead angle.

Description

Specification

Nut member provided with multi-pitch screw and manufacturing method thereof

Technical field

[0001] The present invention relates to a multi-pitch screw having a plurality of leads (the section where the lead angle is loose and the section where the lead angle is steep is changed during one rotation along the screw thread force helical line. The present invention relates to a nut member having a multi-pitch screw) formed so as to be alternately continuous, that is, a female screw having a multi-pitch helical force, and a method of manufacturing the same.

Background art

[0002] The force for which many measures were taken for loosening of the fastening screws was not perfect.

For loosening screws for fastening, screws with multiple leads that are different from the conventional screw concept “spiral with a certain pitch”, that is, lead portions with different pitches are provided continuously. It has been confirmed by the inventors' research that this can be solved by “multi-pitch screw” (Non-patent Document 1).

[0003] Further, the inventors of the present application have applied for the configuration and combination of multi-pitch screw bolts (male screws) and nuts (female screws) having a plurality of leads and applying them to a feed screw mechanism. 2002—Proposed as No. 346891!

[0004] Conventionally, as a bolt member having a multi-pitch screw, that is, a male screw, V-grooves sequentially displaced in the axial direction are provided in communication with the outer peripheral surface of the rod-like member, and the engagement is engaged with this groove. An intermittent feeding device in which a piece is moved intermittently is known. The spiral groove of the screw (feed shaft) of the device is, for example, a large groove portion having a straight deep V groove bottom and a small groove portion having a shallow groove bottom as in the device described in Patent Document 1. When the engaging pieces elastically biased in the groove bottom direction are in sliding contact with opposite side surfaces of the same groove portion, the advance angle is zero and the opposite side surfaces of different groove portions are opposed to each other. Advancing angles are generated when they are in sliding contact with each other!

However, in the intermittent feed device described above, the multi-pitch screw having a plurality of leads is configured such that the engaging pieces elastically biased in the groove bottom direction are in sliding contact with opposite side surfaces of the groove portion. No nuts (female threads) provided with this were disclosed.

[0006] It should be noted that, for example, a helical coil insert described in Patent Document 2 is employed as a technically related and similar to a nut member having a multi-pitch screw of the present invention and a manufacturing method thereof described later. Such female threads are known.

[0007] Similarly, as for a helical coil insert, for example, a wire used for the helical coil insert described in Patent Document 3 and a method for producing a coil insert are known. .

Patent Document 1: No. 3-43488

Patent Document 2: Japanese Patent Publication No. 3-71566

Patent Document 3: Japanese Utility Model Publication 2000-356212

Non-Patent Document 1: Proceedings of the Japan Society of Mechanical Engineers, C, 62 (597), pl963—1968, “Development of an extremely loose screw fastening body”, Hiroshi Fujii, et al., 1996.

Disclosure of the invention

Problems to be solved by the invention

[0008] Numerous proposals for the bolt member having a multi-pitch screw, that is, a male screw, have been studied for practical use. However, a nut member (female screw) having a multi-pitch screw suitable for practical use and a method for manufacturing the nut member are disclosed. Tsu!

[0009] For example, the screw (feed shaft) of the device described in Patent Document 1 is provided with a large groove portion having a linear deep groove bottom and a small groove portion having a shallow groove bottom alternately provided. Therefore, application to a nut member (female screw) was impossible. Further, the thread groove has an uneven depth, and only acts as a multi-pitch screw by the sliding contact combination of the engaging piece elastically biased in the groove bottom direction and the groove portion. The combination with the nut member was not considered.

[0010] Further, the helical coil insert (helical coil insert) described in Patent Document 2 and Patent Document 3 described above relates to a nut member (female screw) based on an ordinary spiral, and the present invention. However, the nut member having the multi-pitch screw and the manufacturing method thereof have not been considered.

Accordingly, the present invention provides a nut member (female screw) provided with a practical multi-pitch screw, and It aims at providing the manufacturing method.

Means for solving the problem

[0012] In order to achieve the above object, a method for producing a nut member having a multi-pitch screw according to claim 1 comprises:

Forming a chevron in which the equal lead angle thread is linearly expanded on one side of the linear member, and forming a chevron in which the multi-pitch thread is linearly expanded on the other side,

Winding the linear member into a coil shape, forming a spiral coil insert having an equal lead angle screw on the outer peripheral surface and a multi-pitch screw on the inner peripheral surface;

Form a nut with an equal lead angle screw on the inner periphery,

A technical feature is that a multi-pitch screw is provided which is formed by screwing an equal lead angle screw on the outer periphery of the coil insert into an equal lead angle screw on the inner periphery of the nut.

[0013] In order to achieve the above object, the nut member having the multi-pitch screw according to claim 6 has a chevron shape in which an equal lead angle thread is linearly developed on one side along the axis. On the other side, an equal lead angle screw is formed on the outer peripheral surface with a multi-pitch thread formed on the outer peripheral surface. A helical coil insert with screws;

A nut having an equal lead angle screw on the inner periphery,

A technical feature is that an equal lead angle screw on the outer periphery of the coil insert is screwed into an equal lead angle screw on the inner periphery of the nut.

The invention's effect

[0014] The inventions of claim 1 and claim 6 form a mountain shape in which an equal lead angle thread is linearly developed on one side of a linear member, and a multi-pitch thread on the other side. Forms an expanded mountain shape. The linear member is wound into a coil shape to form a spiral coil insert having an equal lead angle screw on the outer peripheral surface and a multi-pitch screw on the inner peripheral surface. Then, the equal lead square screw on the outer periphery of the coil insertion body is screwed into the equal lead square screw on the inner periphery of the nut having the equal lead square screw on the inner periphery. Thereby, a nut member provided with a multi-pitch screw can be easily created.

[0015] In the invention of claim 2, a linear member is formed from a metal small-diameter round bar by plastic working. Therefore, processing is easy and practical value is high.

[0016] The invention according to claim 3 is easy to process because the linear member is made of synthetic resin. In particular, when used as a nut member of a feed screw mechanism, by selecting an appropriate synthetic resin material, it is possible to provide a nut member with high screw efficiency by reducing the friction coefficient.

[0017] In the invention according to claim 4, the chevron in which the multi-pitch screw thread of the linear member is developed and the chevron in which the equal-lead square screw thread is developed are projected back to back so that the respective bases overlap. In addition, the base of the chevron that has developed the multi-pitch thread is set to be smaller than the base of the chevron that has developed the equi-lead angle thread, and the base of the chevron that has developed the multi-pitch thread has the same base. A constant distance along the length of the linear member within the range of the width direction of the bottom of the chevron where the lead angle thread is unfolded and within the range of the bottom of the chevron where the equal lead angle thread is unfolded Each time, the bending in the direction perpendicular to the length direction is repeated. For this reason, the cross-sectional area of the linear member can be made substantially constant in the length direction, and plastic working is easy.

[0018] According to the invention of claim 5, the chevron in which the multi-pitch thread of the linear member is developed and the chevron in which the equal-lead square thread is developed are provided so as to protrude back to back so that the respective bases overlap. When the multi-pitch thread is developed, the width of the chevron is repeatedly increased and decreased each time the base advances a certain distance along the length of the linear member. For this reason, the center line of the chevron in which the multi-pitch screw thread is developed and the chevron in which the equal lead angle thread is developed is always constant (straight line), and the design shape can be set efficiently.

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] [First embodiment]

First, the overall shape of the nut member 20 provided with the multi-pitch screw according to the first embodiment of the present invention will be described with reference to FIGS. 1 (A) and 1 (B). FIG. 1 (A) is a perspective view showing a nut member 20 having a multi-pitch screw in the first embodiment, and FIG. 1 (B) is a view of the nut member 20 shown in FIG. 1 (A) in the Y-Y direction. It is sectional drawing. The nut member 20 is based on a known hexagonal nut 21, and a helical coil insert 10 is inserted in the inner peripheral surface of a screw hole 23 provided in the center of the nut 21. A screw hole is formed on the outer peripheral surface of the coil insert 10. A male thread portion 14 force to be screwed into a female screw 24 provided on the inner peripheral surface 23 is provided with a multi-pitch female thread portion 16 formed on the inner peripheral surface.

Next, the detailed shape of the helical coil insert 10 and the manufacturing method thereof will be described with reference to FIGS. 2 (A), 2 (B), and 2 (C).

FIG. 2 (A) is a side view of the linear member 10a as seen from the multi-pitch female thread portion 16 inside the coil insert 10, and FIG. 2 (B) is shown in FIG. 2 (A). FIG. 2C is a plan view of the linear member 10a viewed from the B arrow side, and FIG. 2C is a partially enlarged perspective view showing the linear member 10a. Here, FIG. 2 (A) corresponds to the A arrow view of FIG. 2 (C).

[0021] The linear member 10a is formed in a substantially rhombic cross section by plastic working from a metal small-diameter round bar. On one side along the axis of the linear member 10a, a chevron 101 having a substantially inverted triangular cross-section is continuously formed. On the other side along the axis of the linear member 10a, the above-described peak is formed. A substantially triangular chevron 102 having a base 102a smaller than the base 101a of the shape 101 is continuously formed in a state of being bent in the longitudinal direction.

That is, as shown in FIG. 2C, the chevron 101 and the chevron 102 protrude in opposite directions, and the base 102a of the chevron 102 is set smaller than the base 101a of the chevron 101. Further, every time the distance L is advanced along the length direction of the linear member 10a, the base 102a of the chevron 102 repeats bending while sharing most of the base 101a of the chevron 101. That is, the bending of the chevron 102 is set to be repeated each time the base 102a of the chevron 102 advances the distance L within the range of the base 101a (within the width direction).

[0023] The relationship between Yamagata 101 and Yamagata 102 will be described in more detail with reference to FIG. 3 (A1), FIG. 3 (A2), and FIG. 3 (A3). Fig. 3 (A1) is an enlarged cross-sectional view of the A1-A1 portion of Figs. 2 (A) and 2 (C), and Fig. 3 (A2) is an enlarged cross-sectional view of the A2-A2 portion. (A3) is an enlarged cross-sectional view of the A3-A3 portion. As described above, the chevron 101 and the chevron 102 have the relationship and shape that the bend of the chevron 102 is repeated each time the base 102a of the chevron 102 travels the distance L within the range of the base 101a (within the width direction). It has become. For this reason, one chevron 101 has a shape obtained by linearly extending a chevron of a general spiral screw (equal lead angle), and the other chevron 102 is a multi-pitch screw whose pitch (or lead angle) changes at regular intervals. The shape is a straight extension of the Yamagata. Yamagata 101 height h2, Yamagata 102 height hi is always constant in the length direction.

[0024] Here, the chevron 101 surrounded by the base 101a, the left and right side walls 111, and the top side 112 is illustrated based on an accurate triangle to simplify the explanation and the drawings. In practice, the dimensions are set in advance so as to allow for the deformation amount so as to obtain a normal spiral screw shape (triangular chevron) or a desired chevron shape after coil winding described later. Similarly, the chevron 102 surrounded by the bottom 102a, the left and right side walls 121, and the top 122 is also dimensioned in advance to allow for the amount of deformation due to coil winding in actual design and implementation.

FIG. 3 (B) is a diagram illustrating a method of creating the coil insert 10 from the linear member 10a by coil winding. In FIG. 3 (B), the chevron 101 of the linear member 10a is set on the upper side, and the chevron 102 is set on the lower side, so that it can be fed at the speed set in the direction of arrow F. Yes. The linear member 10a is sent to a known apparatus or machine that performs coil winding processing, is formed into a coil shape, and is cut at notches 10b provided in the linear member 10a at a predetermined interval in advance, and the coil insert 10 Are being made continuously. A tanda 11 is provided at the end of the coil insert 10.

FIG. 3 (C) shows a cross-sectional view of the nut 21. As described above, the female screw 24 is formed in the inner peripheral surface of the screw hole 23 of the nut 21. The wound coil insert 10 is inserted into the screw hole 23 of the nut 21 with a known dedicated tool as disclosed in Patent Document 3 and the like. The tanda 11 used for insertion is similarly cut off with a known dedicated tool after the coil insert 10 is fitted. The state where the insertion of the coil insert 10 is completed is shown in FIGS. 1 (A) and 1 (B).

The coil insert 10 is closely wound, and the outer diameter is set slightly larger than the female screw 24 provided in the screw hole 23 of the nut 21. For this reason, in a state where the coil insert 10 is fitted to the female screw 24 of the nut 21, a force in the expansion direction is always generated in the coil insert 10 and is formed by the chevron 101 on the outer peripheral surface thereof. The male screw 14 is firmly pressed against the female screw 24 of the nut 21.

FIG. 3D is an enlarged perspective view showing a state where the nut 21 is omitted and the coil insert 10 is inserted into the female screw 24 of the nut 21. Close to the outer peripheral surface of the coil insert 10 A normal (equal lead angle) external thread 14 is formed in a body by the contacted chevron 101, and a multi-pitch female thread part 16 is formed by an intimate chevron 102 on the inner peripheral surface of the coil insert 10. ing.

[0029] In the first embodiment, a chevron 101 in which an equal lead angle thread is linearly expanded on one side of the linear member 10a is formed, and a multi-pitch thread is linearly expanded on the other side. Form 10 2. The linear member 10a is wound into a coil shape to form a helical coil insert 10 having a male screw portion 14 with an equal lead angle on the outer peripheral surface and a multi-pitch male screw portion 16 on the inner peripheral surface. . Then, the male screw portion 14 on the outer periphery of the coil insert 10 is screwed into the female screw portion 14 on the inner periphery of the nut 21 that has the female screw portion 14 having an equal lead angle on the inner periphery. Thereby, the nut member 20 provided with the multi-pitch screw can be easily produced.

[0030] In the first embodiment, the metal small-diameter round bar force is also formed by plastic processing of the linear member 10a, so that processing is easy and practical value is high.

[0031] Furthermore, in the first embodiment, the chevron 102 in which the multi-pitch thread of the linear member is developed and the chevron 101 in which the lead angle thread is developed are back to back so that the bases 102a and 101a overlap each other. The base 102a of the projecting 102 that has developed the multi-pitch thread is set smaller than the base 101a of the chevron 101 that has developed the equi-lead angle thread. In the state where the bottom 102a does not protrude from the bottom 101a of the chevron 101 where the equal lead angle thread is unfolded, and within the range in the width direction of the bottom 101a of the chevron 101 where the equal lead angle thread is unfolded, Each time a certain distance L is advanced along the length direction of the shaped member 10a, the bending in the direction perpendicular to the length direction is repeated. For this reason, the cross-sectional area of the linear member 10a can be made substantially constant in the length direction, and plastic working is easy.

[0032] [Modification of first embodiment]

A helical coil insert 10 of a nut member 20 having a multi-pitch screw according to a modification of the first embodiment will be described with reference to FIG.

FIG. 4 (A) is a partially enlarged perspective view showing a linear member 10a according to a modification of the first embodiment, and FIG. 4 (B1) is an illustration of the chevron 102 of the linear member 10a in FIG. 4 (A). FIG. 4 (B2) is an enlarged sectional view of the B2 portion, and FIG. 4 (B3) is an enlarged sectional view of the B3 portion. . In the first embodiment described above with reference to FIGS. 2 and 3, the chevron 102 repeatedly bends within the width of the bottom side 101 a of the chevron 101. On the other hand, in the modified example of the first embodiment, the chevron 102 repeats bending in a range slightly narrower than the width of the base 101a of the chevron 101. Even with the configuration of the modified example of the first embodiment, the same operations and effects as those of the first embodiment can be obtained.

[0033] [Second Embodiment]

Next, the spiral coil insert 10 of the nut member 20 provided with the multi-pitch screw according to the second embodiment will be described with reference to FIG. FIG. 5 (A) is a partially enlarged perspective view showing a linear member 10a ′ constituting the coil insert 10 of the second embodiment, and FIG. 5 (B1) is a linear member 10a in FIG. 5 (A). FIG. 5B is an enlarged cross-sectional view of the B1 portion of “Yamagata 102”, FIG. 5B2 is an enlarged cross-sectional view of the B2 portion, and FIG. 5B3 is an enlarged cross-sectional view of the B3 portion.

[0034] Similar to the linear member 10a of the first embodiment, the linear member 10a 'in the second embodiment is plastically processed from a metal small-diameter round bar, and only the shape of the chevron 102' is different. . As shown in Fig. 5 (B1), Fig. 5 (B2), and (B3), the width of the base 102a 'increases and decreases each time the distance L is increased along the length direction of the linear member 10a'. The cross section is changed and the side wall 121 is set to be a multi-pitch female thread.

[0035] In the second embodiment, the chevron 102 'in which the multi-pitch screw thread of the linear member 10a' is developed and the chevron 101 in which the lead angle screw thread is developed so that the bases 102a 'and 101a overlap each other. The chevron 102 ′ protruding back to back and unfolding multi-pitch threads repeats increasing and decreasing the width each time the base 102a advances a certain distance L along the length direction of the linear member 10a ′. For this reason, the center line C—C of the chevron 102 with the multi-pitch thread and the chevron 101 with the equi-lead angle thread is always constant (straight line), so that the design shape can be set efficiently. be able to.

[0036] [Modification of Second Embodiment]

Furthermore, a helical coil insert 10 of a nut member 20 having a multi-pitch screw according to a modified example of the second embodiment will be described with reference to FIG.

FIG. 6 (A) is a partially enlarged perspective view showing a linear member 10a ′ according to a modification of the second embodiment, and FIG. 6 (B1) is a mountain shape of the linear member 10a ′ in FIG. 6 (A). Fig. 6 (B2) is an enlarged sectional view of the B2 portion, and Fig. 6 (B3) is an enlarged sectional view of the B3 portion. It is. In the second embodiment described above with reference to FIG. 5, the base 102a ′ of the chevron 102 ′ is repeatedly increased and decreased within the width of the base 101a of the chevron 101. On the other hand, in the modified example of the second embodiment, the base 102a ′ of the chevron 102 ′ is repeatedly increased and decreased within a range slightly narrower than the width of the base 101a of the chevron 101. Even in the configuration of the modified example of the second embodiment, the same operations and effects as those of the second embodiment can be obtained.

Industrial applicability

[0037] It should be noted that if the chevron 102 or chevron 102 ', which is not limited to the first and second embodiments described above, repeats stepwise changes at a constant interval, the multi-pitch female thread portion is similarly applied. Needless to say, can be formed.

[0038] Further, in the above-described embodiment, the force described by taking the linear members 10a and 10a 'plastically processed from a metal small-diameter round bar as an example, the present invention is not limited to this.

For example, the linear members 10a and 10a 'can be made of a synthetic resin material, and particularly when used for a nut member of a feed screw mechanism, the friction coefficient can be reduced by selecting an appropriate synthetic resin material. It is possible to provide a nut member with high screw efficiency that is reduced.

[0039] When the linear members 10a and 10a 'are formed of a synthetic resin material, a method such as heating after winding and holding in a coil shape, or directly forming into a coil shape can be taken. The

Furthermore, in the above embodiment, the force line members 10a and 10a ′ described on the assumption of a regular triangular screw can be formed into a trapezoidal shape or a rectangular shape 102 or the mountain shape 102 ′. It can be easily provided.

Brief Description of Drawings

FIG. 1 (A) is a perspective view showing a nut member 20 having a multi-pitch screw according to a first embodiment of the present invention, and FIG. 1 (B) is a perspective view of FIG. 1 (A). FIG. 6 is a cross-sectional view in the Y—Y direction of the nut member 20 shown in FIG.

FIG. 2 (A) is a side view showing the linear member 10a, FIG. 2 (B) is a plan view showing the linear member 10a, and FIG. 2 (C) shows the linear member 10a. It is a partial expansion perspective view.

[Fig. 3] Fig. 3 (A1) is an enlarged cross-sectional view of the A1-A1 portion of Fig. 2 (A), and Fig. 3 (A2) is an enlarged cross-sectional view of the A2-A2 portion of Fig. 2 (A). Figure 3 (A3) is an enlargement of the A3—A3 part of Figure 2 (A) FIG. 3B is a diagram for explaining a method of forming the coil insert 10 from the linear member 10a, FIG. 3C is a sectional view of the nut, and FIG. 1 is an enlarged perspective view showing a coil insert 10. FIG.

[FIG. 4] FIG. 4 (A) is a partially enlarged perspective view showing a linear member 10a according to a modification of the first embodiment, and FIG. 4 (B1) is a view of the linear member 10a in FIG. 4 (A). FIG. 4 is an enlarged sectional view of the B1 portion of the Yamagata 102, FIG. 4 (B2) is an enlarged sectional view of the B2 portion, and FIG. 4 (B3) is an enlarged sectional view of the B3 portion.

FIG. 5 (A) is a partially enlarged perspective view showing the linear member 10a ′ according to the second embodiment, and FIG. 5 (B1) is a mountain shape of the linear member 10a ′ in FIG. 5 (A). Fig. 5 (B2) is an enlarged sectional view of the B2 portion, and Fig. 5 (B3) is an enlarged sectional view of the B3 portion.

FIG. 6 (A) is a partially enlarged perspective view showing a linear member 10a ′ according to a modification of the second embodiment, and FIG. 6 (B1) is a linear member 10a in FIG. 6 (A). FIG. 6 (B2) is an enlarged cross-sectional view of the B2 portion, and FIG. 6 (B3) is an enlarged cross-sectional view of the B3 portion.

Explanation of symbols

10 Coil insert

10a, 10a 'linear member

14 Male thread

16 Multi-pitch male thread

20 Nut member

21 Natsu

23 Screw hole

24 Female thread

101 Yamagata

101a base

102, 102 'Yamagata 112 apex

Claims

The scope of the claims

[1] A linear shape is formed on one side of the linear member by straight development of equi-lead angular threads, and a triangular shape is formed on the other side by linear development of multi-pitch threads.

Winding the linear member into a coil, forming a spiral coil insert having an equal lead angle screw on the outer peripheral surface and a multi-pitch screw on the inner peripheral surface;

Form a nut with an equal lead angle screw on the inner periphery,

A method for producing a nut member having a multi-pitch screw, comprising: engaging an equal lead angle screw on an outer periphery of the coil insert with an equal lead angle screw on an inner periphery of the nut.

2. The method for producing a nut member with a multi-pitch screw according to claim 1, wherein the linear member is formed from a metal small-diameter round bar by plastic working.

[3] The method for producing a nut member having a multi-pitch screw according to claim 1, wherein the linear member is made of a synthetic resin.

[4] The mountain shape of the linear member in which the multi-pitch screw thread is developed and the mountain shape in which the equi-lead angle screw thread is developed are provided so as to protrude back to back so that their bases overlap each other. The base of the expanded chevron is set to be smaller than the base of the chevron where the equal lead angle thread is expanded,

Further, the chevron in which the multi-pitch thread is developed is in a state where the base does not protrude from the base of the chevron in which the equal lead angle thread is developed, and the bottom of the chevron in which the equal lead angle thread is developed. The bending in the direction perpendicular to the length direction is repeated each time a predetermined distance is advanced along the length direction of the linear member within the range in the width direction. A method for producing a nut member comprising any one of the multi-pitch screws.

[5] The mountain shape of the linear member in which the multi-pitch screw thread is developed and the mountain shape in which the equi-lead angle screw thread is developed are provided so as to protrude back to back so that their bases overlap, and the multi-pitch screw thread The multi-pitch screw with a force 1 according to any one of claims 1 to 3, wherein the expanded chevron is repeatedly increased and decreased each time the bottom of the chevron advances a certain distance along the length direction of the linear member. The manufacturing method of the nut member provided.

[6] A chevron is formed on one side along the axis, with an equal lead angle thread developed linearly, the other On the other side, an equal lead angle screw is formed on the inner peripheral surface of the outer peripheral surface by winding a linear member having a chevron shape in which a multi-pitch screw thread is linearly formed into a coil shape. A helical coil insert provided with a screw,

A nut having an equal lead angle screw on the inner periphery,

A nut member provided with a multi-pitch screw, wherein an equal lead square screw on the outer periphery of the coil insert is screwed onto an equal lead square screw on the inner circumference of the nut.

A coil insert made of resin with an equal lead angle screw on the outer peripheral surface and a multi-pitch screw on the inner peripheral surface;

A metal nut having an equal lead angle screw on the inner periphery,