JP2006046546A - Nut member with multipitch screw and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a nut member with a practical multipitch screw. <P>SOLUTION: A linear member 10a which has a crest 101 formed by linearly developing an equal lead angle screw thread and a crest 102 formed by linearly developing a multipitch screw thread is machined into a coiled shape to form a spiral coil insert 10 which has an equal lead angle female screw 14 on the outer peripheral face and a multipitch male screw 16 on the inner peripheral face. The coil insert 10 is threaded to a nut 21 which has the equal lead angle female screw 14 on the inner periphery. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, 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 alternately while the thread of the screw rotates once along the spiral line. The present invention relates to a nut member having a multi-pitch screw formed so as to be continuous, that is, a female screw composed of a multi-pitch spiral, and a manufacturing method thereof.

Many measures have been taken to loosen the fastening screws, but none of them were perfect.
For the loosening of the screw for fastening, a multi-screw with a plurality of leads in which the concept of the conventional screw “spiral with a certain pitch” is changed, that is, a lead portion having a different pitch is continuously provided. It has been confirmed by research of the inventors of the present case that it can be solved by “pitch screw” (Non-Patent Document 1).

  Japanese Patent Application No. 2002-346891 has been developed by the inventors of the present application to construct and combine multi-pitch screw bolts (male screws) and nuts (female screws) having a plurality of leads and to apply them to a feed screw mechanism. As proposed.

  Conventionally, as a bolt member having a multi-pitch screw, that is, a male screw, a groove that is sequentially displaced in the axial direction is provided on the outer peripheral surface of the rod-shaped member, and an engagement piece that engages with this groove is intermittent. Intermittent feeders that are moved in a conventional manner are known. As for the spiral groove of the screw (feed shaft) of the device, for example, as in the device described in Patent Document 1, a large groove portion having a straight deep groove bottom and a small groove portion having a shallow groove bottom are alternately arranged. 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 when the sliding pieces are in contact with the opposite side surfaces of different groove portions, respectively. A lead angle is generated.

  However, in the above intermittent feed device, a nut (female screw) provided with a multi-pitch screw having a plurality of leads, in which the engaging pieces elastically biased in the groove bottom direction are in sliding contact with opposite side surfaces of the groove portion. There was no disclosure about.

  In addition, as a thing related technically and similar to the nut member provided with the multi-pitch screw of the present invention described later and a manufacturing method thereof, for example, a female screw adopting a helical coil insert described in Patent Document 2 is provided. It is known.

Similarly, the thing regarding the manufacturing method of the wire used for it and a coil insert like it, for example like the wire for helical coil insert described in patent document 3, as a thing regarding a helical coil insert is known.
Japanese Utility Model Publication No. 3-43488 Japanese Patent Publication No. 3-71566 Japanese Utility Model Publication No. 2000-356212 Transactions of the Japan Society of Mechanical Engineers, volume C, volume 62 (597), p1963-1968, “Development of screw fasteners that are extremely resistant to loosening”, Hiroshi Fujii, et al., 1996.

  Numerous proposals and practical studies have been made on bolt members having multi-pitch screws, that is, male screws, but there are no nut members (female screws) equipped with multi-pitch screws suitable for practical use and their manufacturing methods. It was.

  For example, the screw (feed shaft) of the device described in Patent Document 1 is provided with a large groove portion having a straight deep groove bottom and a small groove portion having a shallow groove bottom alternately communicated with each other. Application to a nut member (female thread) was impossible. Furthermore, the thread groove has a non-uniform depth, and exhibits an action as a multi-pitch screw only 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.

  Further, the helical coil insert (helical coil insert) described in Patent Document 2 and Patent Document 3 relates to a nut member (female screw) based on an ordinary spiral, and the multi-pitch screw of the present invention. The nut member provided with and the manufacturing method thereof were not considered.

  Then, an object of this invention is to provide the nut member (female screw) provided with the practical multi pitch screw, and its manufacturing method.

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 that linearly develops equal lead angle threads on one side of the linear member, and forming a chevron that linearly develops multi-pitch threads 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.

In order to achieve the above object, the nut member having the multi-pitch screw according to claim 6 is formed with a chevron shape in which an equal lead angle thread is linearly developed on one side along the axis, and the other On the side, a linear member in which a multi-pitch thread is linearly developed is wound into a coil, and an equi-lead square screw is provided on the outer peripheral surface, and a multi-pitch screw is provided on the inner peripheral surface. A helical coil insert,
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 to an equal lead angle screw on the inner periphery of the nut.

  According to the first and sixth aspects of the present invention, a chevron in which an equal lead angle thread is linearly developed on one side of the linear member and a multi-pitch thread is linearly developed on the other side is formed. Form. This linear member is wound into a coil shape to form a helical 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 angle screw on the outer periphery of the coil insert is screwed into the equal lead angle screw on the inner periphery of the nut having the equal lead angle screw on the inner periphery. Thereby, the nut member provided with the multi-pitch screw can be easily created.

  According to the second aspect of the present invention, since the linear member is formed from a metal small-diameter round bar by plastic working, the processing is easy and the practical value is high.

  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, it is possible to provide a nut member with high screw efficiency by reducing the friction coefficient by selecting an appropriate synthetic resin material.

  According to a fourth aspect of the present invention, there is provided a multi-pitch screw in which a chevron shape in which a multi-pitch thread of a linear member is developed and a chevron shape in which an equileaded angle screw thread is developed are projected back to back so that the respective bases overlap. The base of the chevron where the ridge is expanded is set to be smaller than the base of the chevron where the equi-lead angle thread is unfolded. Furthermore, the base where the multi-pitch thread is unfolded develops the equi-lead angle thread. Each time it advances a certain distance along the length direction of the linear member within the range of the width direction of the bottom of the chevron where the lead angle thread is unfolded in a state that does not protrude from the bottom of the chevron, Repeats bending in the direction perpendicular to the length direction. 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.

  According to a fifth aspect of the present invention, there is provided a multi-pitch screw in which a chevron in which a multi-pitch thread of a linear member is developed and a chevron in which an equi-lead angular thread is developed are back-to-back so that the respective bases overlap each other. The mountain shape in which the mountain is developed repeats the increase and decrease of the width every time the bottom of the mountain progresses a certain distance along the length direction 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 screw thread is developed is always constant (straight line), and design shape setting can be performed efficiently.

[First embodiment]
First, with reference to FIG. 1 (A) and FIG. 1 (B), the whole shape of the nut member 20 provided with the multi-pitch screw which concerns on 1st Embodiment of this invention is demonstrated. FIG. 1A is a perspective view showing a nut member 20 provided with a multi-pitch screw in the first embodiment, and FIG. 1B is a cross section in the YY direction of the nut member 20 shown in FIG. FIG. 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 male screw portion 14 is formed on the outer peripheral surface of the coil insert 10 to be engaged with a female screw 24 provided on the inner peripheral surface of the screw hole 23. A multi-pitch female screw portion 16 is formed on the inner peripheral surface. ing.

Next, the detailed shape of the helical coil insert 10 and the manufacturing method thereof will be described with reference to FIGS.
2A is a side view of the linear member 10a as viewed from the multi-pitch female thread 16 side inside the coil insert 10, and FIG. 2B is a line shown in FIG. It is the top view which looked at the linear member 10a from the B arrow side, and FIG.2 (C) is the elements on larger scale which show the linear member 10a. Here, FIG. 2 (A) corresponds to the A arrow view of FIG. 2 (C).

  The linear member 10a has a substantially diamond-shaped cross section by plastic working from a metal small-diameter round bar. A chevron 101 having a substantially inverted triangular cross-section is continuously formed on one side along the axis of the linear member 10a, and the above chevron is formed on the other side along the axis of the linear member 10a. The substantially triangular chevron 102 of the base 102a smaller than the base 101a of 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, each time the distance L is advanced along the length direction of the linear member 10 a, the bottom 102 a of the mountain 102 is repeatedly bent while sharing most of the bottom 101 a of the mountain 101.
That is, the bending of the chevron 102 is set to be repeated every time the base 102a of the chevron 102 advances the distance L within the range of the base 101a (within the width direction).

  The relationship between the chevron 101 and the chevron 102 will be described in further detail with reference to FIGS. 3A1, 3A2, and 3A3. 3A1 is an enlarged cross-sectional view of the A1-A1 portion in FIGS. 2A and 2C, and FIG. 3A2 is an enlarged cross-sectional view of the A2-A2 portion. (A3) is an enlarged sectional view of the A3-A3 portion. As described above, the chevron 101 and the chevron 102 have a relationship and a shape in which the bending 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 is 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 mountain. The height h2 of the chevron 101 and the height h1 of the chevron 102 are always constant in the length direction.

  Here, the chevron 101 surrounded by the base 101a, the left and right side walls 111, and the top 112 is illustrated based on an accurate triangle to simplify the description and the drawings, but in actual design and implementation, The dimensions are set in advance so as to obtain a 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 side 102a, the left and right side walls 121, and the top side 122 is also dimensioned to allow for the amount of deformation due to coil winding in advance in actual design and implementation.

  FIG. 3B is a diagram for explaining a method of creating the coil insert 10 from the linear member 10a by coil winding. In FIG. 3B, the chevron 101 of the linear member 10a is set on the upper side, and the chevron 102 is set on the lower side, and the linear member 10a is fed at a speed set in the direction of the arrow F. Yes. The linear member 10a is sent to a known device or machine that performs coil winding processing, is formed into a coil shape, and is cut in advance at predetermined intervals at notches 10b provided in the linear member 10a. Is made continuously. A tongue 11 is provided at the end of the coil insert 10.

  FIG. 3C 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 insertion body 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 tongue 11 used for the insertion is similarly cut off with a known special tool after the coil insert 10 is inserted. A 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, when the coil insert 10 is inserted into the female screw 24 of the nut 21, a force in the expansion direction is always generated in the coil insert 10, and the male screw formed by the chevron 101 on the outer peripheral surface thereof. 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. A normal (equal lead angle) male screw 14 is formed in a body shape by an intimate chevron 101 on the outer peripheral surface of the coil insert 10, and an intimate chevron 102 is in contact with the inner peripheral surface of the coil insert 10. A multi-pitch female thread portion 16 is formed.

  In the first embodiment, a chevron 101 in which equal lead angle threads are linearly expanded is formed on one side of the linear member 10a, and a chevron 102 in which multi-pitch threads are linearly expanded is formed on the other side. To do. The linear member 10a is wound into a coil shape to form a helical coil insert 10 having a male screw portion 14 having 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 having 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 created.

  In the first embodiment, since the linear member 10a is formed by plastic working from a metal small-diameter round bar, processing is easy and practical value is high.

  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 equi-lead angular thread is developed are projected back to back so that the bases 102a and 101a overlap each other. The bottom 102a of the chevron 102 in which the multi-pitch thread is developed is set to be smaller than the base 101a of the chevron 101 in which the equi-lead angular thread is developed. The linear member 10a is in a state where the bottom side 102a does not protrude from the bottom side 101a of the chevron 101 where the equal lead angle thread is developed, and within the range in the width direction of the bottom side 101a of the chevron 101 where the equal lead angle thread is developed. Each time a certain distance L is advanced along the length direction, 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.

[Modification of the 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. 4A is a partially enlarged perspective view showing a linear member 10a according to a modification of the first embodiment, and FIG. 4B1 is B1 of a mountain shape 102 of the linear member 10a in FIG. FIG. 4B2 is an enlarged sectional view of the portion B2, and FIG. 4B3 is an enlarged sectional view of the portion B3. 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 in the configuration of the modified example of the first embodiment, the same operations and effects as those of the first embodiment can be obtained.

[Second Embodiment]
Next, the helical 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). 5B is an enlarged cross-sectional view of the B1 portion of FIG. 5B, 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.

  The linear member 10a 'in the second embodiment is plastic-worked from a metal small-diameter round bar like the linear member 10a in the first embodiment, 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 or 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 portion.

  In the second embodiment, the chevron 102 ′ in which the multi-pitch thread of the linear member 10a ′ is developed and the chevron 101 in which the equal lead angle screw thread is developed project back to back so that the bases 102a ′ and 101a overlap each other. The chevron 102 ′ provided with the multi-pitch screw thread is repeatedly increased and decreased 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 in which the multi-pitch thread is developed and the chevron 101 in which the equal lead angle thread is developed is always constant (straight line), and the design shape setting can be performed efficiently. Can do.

[Modification of Second Embodiment]
Furthermore, the helical coil insert 10 of the nut member 20 provided with the multi-pitch screw according to the modified example of the second embodiment will be described with reference to FIG.
FIG. 6A is a partially enlarged perspective view showing a linear member 10a ′ according to a modification of the second embodiment, and FIG. 6B1 is a mountain shape 102 of the linear member 10a ′ in FIG. 6A. FIG. 6B is an enlarged cross-sectional view of the B2 portion, and FIG. 6B3 is an enlarged cross-sectional view of the B3 portion. In the second embodiment described above with reference to FIG. 5, the base 102 a ′ of the chevron 102 ′ is repeatedly increased and decreased within the width of the base 101 a of the chevron 101. In contrast, in the modified example of the second embodiment, the base 102a ′ of the chevron 102 ′ is repeatedly increased and decreased in 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.

  In addition, without being limited to the first and second embodiments described above, if the chevron 102 or the chevron 102 ′ repeats a stepwise change at a constant interval, it is possible to form a multi-pitch female thread portion similarly. Needless to say.

Moreover, in said embodiment, although linear member 10a, 10a 'plastically processed from the metal small diameter round bar was demonstrated to the example, this 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. Thus, a nut member with high screw efficiency can be provided.

When the linear members 10a and 10a ′ are formed of a synthetic resin material, a method of heating after winding and holding in a coil shape, or directly forming into a coil shape can be taken.
Furthermore, in the above embodiment, the description has been made on the premise of a normal triangular screw. However, the mountain shape 102 or the mountain shape 102 'of the linear members 10a and 10a' can be formed into a trapezoidal shape or a rectangular shape. It can be provided very easily.

FIG. 1A is a perspective view showing a nut member 20 provided with a multi-pitch screw according to the first embodiment of the present invention, and FIG. 1B is a view of Y- of the nut member 20 shown in FIG. It is sectional drawing of a Y direction. 2A is a side view showing the linear member 10a, FIG. 2B is a plan view showing the linear member 10a, and FIG. 2C is a partially enlarged perspective view showing the linear member 10a. It is. 3A1 is an enlarged cross-sectional view of the A1-A1 portion of FIG. 2A, FIG. 3A2 is an enlarged cross-sectional view of A2 and A2 portion of FIG. 2A, and FIG. ) Is an enlarged cross-sectional view of the A3-A3 portion of FIG. 2A, and FIG. 3B is a view for explaining a method of forming the coil insert 10 from the linear member 10a. FIG. 3D is an enlarged perspective view showing the coil insert 10. FIG. 4A is a partially enlarged perspective view showing a linear member 10a according to a modification of the first embodiment, and FIG. 4B1 is B1 of a mountain shape 102 of the linear member 10a in FIG. FIG. 4B2 is an enlarged sectional view of the portion B2, and FIG. 4B3 is an enlarged sectional view of the portion B3. FIG. 5 (A) is a partially enlarged perspective view showing the linear member 10a ′ according to the second embodiment, and FIG. 5 (B1) is B1 of the chevron 102 ′ 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. 6A is a partially enlarged perspective view showing a linear member 10a ′ according to a modification of the second embodiment, and FIG. 6B1 is a mountain shape 102 of the linear member 10a ′ in FIG. 6A. FIG. 6B is an enlarged cross-sectional view of the B2 portion, and FIG. 6B3 is an enlarged cross-sectional view of the B3 portion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Coil insert 10a, 10a 'Linear member 14 Male thread part 16 Multi-pitch male thread part 20 Nut member 21 Nut 23 Screw hole 24 Female thread 101 Mountain shape 101a Bottom side 102, 102' Mountain shape 102a Bottom side 111 Side wall 112 Top side 121 Side wall

Claims (7)

Forming a chevron that linearly develops equal lead angle threads on one side of the linear member, and forming a chevron that linearly develops multi-pitch threads 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 method for producing a nut member having a multi-pitch screw, comprising: engaging an equal lead square screw on the outer periphery of the coil insert with an equal lead square screw on the inner circumference of the nut. 2. The method for producing a nut member having a multi-pitch screw according to claim 1, wherein the linear member is formed from a metal small-diameter round bar by plastic working. 2. The method for manufacturing a nut member having a multi-pitch screw according to claim 1, wherein the linear member is formed of a synthetic resin. The chevron in which the multi-pitch screw thread of the linear member is developed and the chevron in which the equi-lead angular thread is developed protrude back to back so that the respective bases overlap, and the chevron that develops the multi-pitch thread. Is set smaller than the base of the chevron where the equal lead angle thread is developed,
Further, the chevron that has developed the multi-pitch thread has a bottom that does not protrude from the base of the chevron that has developed the equi-lead angular thread, and the width of the base of the chevron that has developed the equi-lead angular thread. 4. The bending in the direction perpendicular to the length direction is repeated each time a certain distance is traveled along the length direction of the linear member within the range of the direction. 5. A method for producing a nut member having one multi-pitch screw. The chevron in which the multi-pitch screw thread of the linear member is developed and the chevron in which the equi-lead angular thread is developed protrude back to back so that the respective bases overlap, and the chevron that develops the multi-pitch thread. 4. The nut having a multi-pitch screw according to any one of claims 1 to 3, wherein the width of the base is repeatedly increased and decreased every time the base advances a certain distance along the length direction of the linear member. Manufacturing method of member. A coiled linear member is formed on one side along the axis, in which an equileaded angle thread is linearly expanded, and on the other side, a multi-pitch thread is linearly expanded. 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,
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 inner periphery of the nut is screwed with an equal lead square screw on the outer periphery of the coil insert. A coil insert made of resin having 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,
A nut member provided with a multi-pitch screw, wherein an equal lead square screw on the inner periphery of the nut is screwed with an equal lead square screw on the outer periphery of the coil insert.

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