JP2011078993A - Form rolling die and method for form-rolling bolt with profile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a form rolling die which can securely and inexpensively form a bolt (screw) with a profile combining a male screw part located at least at one end and a profile having a non-circular cross-section from a columnar sock by single form rolling stage, and to provide a method for form-rolling a bolt with a profile. <P>SOLUTION: The form rolling die 1 includes: a pair of upper and lower male screw forming regions 7, 7 located at a pair of confronted forming faces 3a, 3b in a pair of flat dies 2a, 2b and composed of two or more pairs of mountain parts 8 and valley parts 9 parallel each other and also tilted to the feeding direction of a stock W0; and a region 10 of forming a profile with a non-circular cross-section located in parallel between the male screw forming parts 7, 7 in the pair of forming faces 3a, 3b, and in which a plurality of arc form parts 14, 15, 16 are projectingly provided at equal intervals (equal pitch p) along the feeding direction of a stock W0. The plurality of arc form parts 14 to 16 in the profile forming region 10 are projectingly provided in such a manner that the cross-sections of the arc form parts 14 to 16 are successively made larger in order of a chamfering part 4, a parallel part 5 and a relief part 6 in the forming region 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rolling die for rolling a bolt (screw) having a deformed portion having a non-circular cross section, and a method for rolling a deformed bolt using the same.

For example, when rolling a non-circular screw such as a hexagon in the axial direction, such as a tapping screw, a screw with a circular cross section along the bite portion, parallel screw portion, and relief portion of a flat die A plurality of ridges of a certain height for forming the valleys are projected in parallel, and a large number of continuous undulations for forming a non-circular thread between these ridges are engraved at an equal pitch. A manufacturing method for obtaining a set corrugated flat die has been proposed (see, for example, Patent Document 1).
By facing the pair of corrugated flat dies, sandwiching a thread rolling material in which a large-diameter bolt head is forged at one end in advance between them, and moving the pair of corrugated flat dies in opposite directions, A tapping screw having a non-circular thread can be rolled.

By the way, when manufacturing a shaft-like part having both a large-diameter part and a small-diameter part adjacent to the male thread part like a watch winding stem, a rod-shaped material is forged, and a large After forming the small diameter part, the intermediate material obtained is rolled by a pair of flat dies having two corresponding parts that allow the large and small diameter parts to escape. A method for manufacturing a component has been proposed (see, for example, Patent Document 2).
Furthermore, the male threaded part on one end to be fixed to a metal plate has male threaded parts on both ends, like a screw-in stud bolt, and the cross section is non-circular such as a square or hexagon. In the case of rolling a bolt having a square pillar part, after forging a cylindrical material in advance and forming a non-circular square pillar part at the axial intermediate position, the intermediate material is paired with a pair of flat dies. In between the biting portion for each of a pair of parallel screw forming surfaces spaced apart corresponding to the prismatic portion, the parallel screw portion, and the escape portion, by sliding the pair of flat dies in the opposite direction, A two-stage manufacturing process in which forging and rolling are different, in which male thread portions are rolled at both ends of the intermediate material, is necessary.
For this reason, there has been a problem that the shape and position accuracy of the male screw portion and the non-circular deformed portion having a non-circular cross-section are likely to be unstable and the cost is increased through a plurality of man-hours.

JP-A-7-178626 (pages 1-6, FIGS. 1-7) JP 2001-286964 A (pages 1 to 6, FIGS. 1 to 4)

  The present invention solves the problems described in the background art, and is provided with a deformed portion bolt (screw) having both a male thread portion located at least on one end side and a deformed portion having a non-circular cross section from a cylindrical material. It is an object of the present invention to provide a rolling die that can be reliably and inexpensively formed in a single rolling step, and a method for rolling a bolt with a deformed portion using the rolling die.

Means for Solving the Problems and Effects of the Invention

In order to solve the above-mentioned problems, the present invention provides a pair of arcuate portions facing each other while the material is rotated and fed between a pair of male screw forming regions where a male screw is rolled. It is conceived that the non-circular shaped section having a non-circular cross section is formed in parallel by alternately applying the pressure and the release thereof by a plurality of times.
That is, the rolling die of the present invention (Claim 1) is a male screw comprising a plurality of sets of crests and troughs located on a pair of opposed molding surfaces and parallel to each other and inclined with respect to the feed direction of the material. A non-circular deformed portion having a non-circular cross section that is located in parallel with the male thread forming portion on the forming region and the pair of forming surfaces, and has a plurality of arc-shaped portions protruding at equal intervals along the feed direction of the material A plurality of arc-shaped portions in the deformed portion forming region such that the cross-section of the arc-shaped portion sequentially increases in the order of the biting portion, the parallel portion, and the relief portion of the forming region. It is characterized by being protruding.

According to this, between the male thread forming regions opposed to each other, the plurality of sets of ridges extending between the biting portion, the parallel portion, and the escape portion while rotating the cylindrical material along the circumferential direction thereof. By forming the screw thread and the screw valley on the peripheral surface of the material so as to be successively higher or deeper by plastic deformation by the portion and the valley portion, the male screw portion is engraved on at least one end side of the material. In parallel with this, a plurality of arc-shaped portions spanning the biting portion, the parallel portion, and the relief portion in the deformed portion forming region due to the propulsive force in the feeding direction accompanied by the rotation of the material at the time of forming the male screw portion. , And a flat surface or a recessed surface located between them, and the peripheral surface excluding the male screw portion of the material is pressured by a pair of arcuate portions that press the material facing centripetally , And release of pressure by a pair of opposed flat surfaces or the like alternately. As a result, on the peripheral surface other than the male screw portion of the material, a flat surface that has been depressed by receiving a pair of opposing pressures and a surplus in the vicinity of the flat surface in association with a plurality of times of the pressure and the release thereof. Are formed in accordance with plastic deformation that is unevenly distributed in the circumferential direction, and are formed into an irregular shape having a non-circular cross section and a plurality of flat surfaces symmetrically from the initial circular cross section.
Therefore, according to the rolling die as described above, the bolt with the deformed portion having both the male screw portion and the deformed portion having a non-circular cross section is accurately and reliably formed from a cylindrical material by a single rolling process. It becomes possible to mold quickly and inexpensively.

In addition, as described below, the pair of molding surfaces includes a form located for each opposed surface of the pair of circular dies, as well as a form located for each opposed circumferential surface of the pair of circular dies. It is.
Further, the deformed portion forming region is positioned parallel to the male screw forming region along the feed direction of the material, and as described later, the two types of forming regions are adjacent to each other, or They are arranged at regular intervals across a flat surface.
Furthermore, the plurality of arc-shaped portions protruding from the deformed portion forming region have a cross-sectional arc (curve) shape along a direction orthogonal to the feed direction of the material, and the cross-sections are substantially similar to each other and are entirely formed. In addition to the curved surface having a substantially bowl shape, the distance (pitch) between the central portions of each arc-shaped portion along the feed direction of the material is set equally over the biting portion, the parallel portion, and the relief portion. ing.

The plurality of arc-shaped portions projecting from the deformed portion forming region have a configuration in which each adjacent cross section gradually increases (higher and wider) along the feed direction of the material. A configuration in which two or three adjacent sections have the same cross-sectional shape along the direction and the section gradually increases in units of two or three is also included.
Furthermore, the cross-sectional shape in the axial direction of the deformed portion includes, for example, an oval shape including a pair of parallel flat surfaces in addition to a substantially regular polygon of a triangle or more. For these cross-sectional shapes, the pitch between the plurality of arc-shaped portions, or the height at which the plurality of arc-shaped portions protrude from the flat surface and the width along the feed direction are adjusted to different relationships. Thus, it can be appropriately selected.
In addition, the molded product in which the male screw part is formed on one end side of the material and the deformed part is formed on the other end side is, for example, a headed bolt (screw) having two or more flat surfaces in a horizontal direction, A welded stud bolt having a profile for welding fillet at one end.

Further, in the present invention, the male screw forming region and the deformed portion forming region are disposed adjacent to or separated from each other on the forming surfaces facing a pair of flat dies, or in a pair of circular dies. Also included are rolling dies (Claim 2) that are arranged adjacent to or apart from each other in the axial direction for each of the cylindrical molding surfaces.
According to this, for each of the forming surfaces facing a pair of flat dies, the male thread forming region and the deformed portion forming region are disposed adjacent to or apart from each other, or a cylindrical shape in the pair of circular dies. Each molding surface is disposed adjacent to or apart from the axial direction. Therefore, by moving the pair of flat dies in the opposite directions or rotating the pair of circular dies in the same direction, the material has a male screw portion on at least one end side, and this The bolt with the deformed portion having the deformed portion sandwiching the shaft portion adjacent to the original or the original cylindrical shape can be reliably, accurately, rapidly and inexpensively formed by a single rolling process.

Further, according to the present invention, the male thread forming region is disposed in parallel on both sides of the deformed portion forming region orthogonal to the feed direction of the material, and is disposed adjacent to or apart from the pair. A rolling die (Claim 3) is also included in which the crests and troughs in each male thread forming region are in the same direction or in opposite directions.
According to this, a pair of male screw portions are formed in the same screw direction or reverse screw direction on both ends of the material, and the deformed portion is sandwiched between these adjacent or original cylindrical shaft portions, A single rolling process enables reliable molding.
An example of a molded article having a pair of male screw portions in the same screw direction at both ends and having a deformed portion therebetween is, for example, a screw-in stud bolt. On the other hand, a molded article having a pair of male screw portions in the opposite screw direction on both ends and having a deformed portion therebetween includes, for example, a reverse screw bolt with a screw head (deformed portion).
In addition, two or more deformed portion molding regions can be provided adjacent to or separated from each other on one molding surface. By using a rolling die having such a forming surface, a bolt with a deformed portion having two or more deformed portions adjacent to or separated from each other can be rolled.

  On the other hand, the method of rolling a bolt with a deformed portion according to the present invention (Claim 4) uses any one of the above rolling dies, and between the biting portions facing a pair of molding surfaces in the rolling die, A preparatory step in which a cylindrical material has its axial direction orthogonal to the feed direction and is rotatably held, and the pair of molding surfaces are moved or rotated in opposite directions, whereby the pair of molding surfaces are opposed to each other. A molding step in which the material is sandwiched and fed while rotating in the order between the attached parts, between the parallel parts, and between the escape parts.

According to this, after the cylindrical material is sandwiched between the biting portions facing each other with a pair of molding surfaces in the preparation step, the bite facing the pair of molding surfaces is formed in the molding step. The centripetal direction by a pair of arc-shaped portions facing each other between the plurality of arc-shaped portions whose cross sections gradually increase in the order between the attached portions, between the parallel portions, and between the escape portions. And the release of the upper pressure by the flat surface or the recessed surface between the arcuate portions adjacent in the feed direction are alternately received.
Therefore, in the molding step, the material is sandwiched between arc-shaped portions whose cross sections gradually increase in the order of the biting portion, the parallel portion, and the relief portion, so that the circular cross section is gradually symmetrical in the circumferential direction. It is formed into a cross-sectional shape having a plurality of flat surfaces (two or more). At the same time, due to the uneven thickness near the surface layer of the material due to the release of pressure when sandwiched between flat surfaces or concave surfaces where the width in the feeding direction gradually decreases in the above order, A corner (near the ridgeline) is formed between them.
Therefore, by a single forging process including a continuous preparation step and a forming step, a deformed portion having a non-circular shaped portion having a non-circular cross section at the same time as a male screw portion by the male screw forming region for a cylindrical material. Attached bolts (screws) can be rolled reliably and quickly.
The pair of flat dies having the pair of molding surfaces or the pair of circular dies are supported by a rolling device that can move in the reverse direction or rotate in the same direction.

Further, in the present invention, in the molding step, the molded portion of the material that is fed while rotating between the pair of opposed deformed portion molding regions is substantially a regular polygon having a non-circular cross section. Alternatively, there is also included a method of rolling a bolt with a deformed portion in which a substantially oval shaped deformed portion is formed (Claim 5).
According to this, in the molding step, the part to be molded of the material is sandwiched between arc-shaped parts whose cross sections gradually increase in the order of the biting part, the parallel part, and the escape part, so that the original circular shape is obtained. A cross section with a plurality of flat surfaces that are gradually symmetric in the radial direction is formed into a substantially regular polygonal section or a substantially oval shaped deformed section, and the male thread section is rolled simultaneously with or adjacent to the axial direction. Is done. Therefore, the bolt with a deformed portion can be formed quickly and inexpensively by a single rolling process.

The front view which illustrates one molding surface in a pair of flat dies by the present invention. The top view of the said flat die. The horizontal sectional view in alignment with the arrow of the XX in FIG. FIG. 2 is a vertical cross-sectional view of a pair of flat dies including a view of the YY line in FIG. 1. The schematic of the rolling process of the external thread with respect to the raw material by said pair of flat die | dye. Schematic which shows the rolling process of the external thread following FIG. Schematic which shows the cross section of the rolling process of the external thread following FIG. 6, and the bolt with a deformed part. The schematic diagram of the formation process of the deformed part to the material by the above-mentioned pair of flat dies. The perspective view of the bolt with a deformed part obtained by the said rolling process and a formation process. The front view which illustrates one molding surface in the flat die | dye of an application form. Schematic which shows the shaping | molding behavior of the raw material between the said flat dies, and an intermediate raw material. Schematic which shows the shaping | molding behavior of the intermediate material following FIG. The perspective view which shows the bolt with a deformed part obtained using the said flat die. The front view which illustrates one molding surface in the flat die of a different form. The perspective view which shows the bolt with a deformed part obtained using the said flat die. Furthermore, the front view which illustrates one molding surface in the flat die of a different form. The perspective view which shows the bolt with a deformed part obtained using the said flat die. The front view which illustrates one molding surface in the flat die of another form. The perspective view which shows the bolt with a deformed part obtained using the said flat die. The schematic plan view which shows the form by a pair of circular die | dye by this invention.

Hereinafter, modes for carrying out the present invention will be described.
FIG. 1 is a front view illustrating the molding surfaces 3a and 3b of the pair of flat dies 2a and 2b constituting the rolling die 1 of the present invention as a molding surface 3a on the flat die 2a side, and FIG. 3 is a plan view of the flat die 2a, FIG. 3 is a horizontal sectional view taken along the line XX in FIG. 1, and FIG. 4 is a rolling die including the line YY in FIG. 1 is a vertical sectional view of FIG. 1 to 3, the right side relative to the left side is referred to as a feeding direction.
The flat die 2a (2b) is formed, for example, of a tool steel such as the SDK 11 and has a substantially rectangular parallelepiped shape. As shown in FIGS. (3b) are opposed to each other.
The molding surface 3a (3b) has a biting portion 4 on the left end side, a relatively long parallel portion 5 in the center, and a relief portion 6 on the right end side, along the feed (lateral) direction of the material described later. These upper and lower sides have a pair of upper and lower male thread forming regions 7 and 7 and a deformed portion forming region 10 sandwiched between them in parallel along the feed direction. As shown in FIG. 2, the biting part 4 and the escape part 6 are slightly inclined with respect to the parallel part 5.

As shown in FIGS. 1, 2, and 4, the pair of upper and lower male screw forming regions 7 and 7 form a thread portion and a thread portion 8 having a substantially triangular cross section for forming a thread valley on the peripheral surface of the material. For this purpose, a plurality of valley portions 9 having a substantially V-shaped cross section are provided in parallel with each other, which are slightly inclined in the same direction (lower side in FIG. 1) with respect to the feed direction of the material. The crest 8 has a crest 4, a parallel 5, and a clearance 6, and the crest 8 is gradually increased in height and wide at the bottom. In order of the relief portion 6, the opening portion is formed so as to be gradually deeper and wider.
On the other hand, as shown in FIGS. 1, 3, and 4, the deformed portion molding region 10 has a cross-sectional arc (curve) from the surfaces 11 and 12 of the biting portion 4 and the parallel portion 5 and the plurality of recessed surfaces 13 in the relief portion 6. A plurality of arc-shaped portions 14, 15, 16 having a shape are circles at equal intervals (equal pitch) p and in the order of the biting portion 4, the parallel portion 5, and the relief portion 6 of the molding region 10. The arc-shaped portion protrudes so that the cross section of the arc-shaped portion gradually increases.

The adjacent arc-shaped portions 14 and 14, the arc-shaped portions 15 and 15, and the arc-shaped portions 16 and 16 are not limited to the form in which the cross section on the feeding side is always large (high and wide). A pair of adjacent (two) or three adjacent ones have the same cross-sectional shape, and a pair of (two) on the feed side, or an arcuate portion 14 that is slightly larger for each unit of three. , 15 and 16 may be projected in sequence.
Further, as shown in FIG. 4, the flat dies 2a and 2b include a portion having a pair of upper and lower male screw forming regions 7 and 7 and a portion having a deformed portion forming region 10 sandwiched therebetween in advance. Each of the steel pieces is manufactured and connected by a bolt (not shown) so that the molding surfaces 3a and 3b are axisymmetrically assembled. However, it is also possible to form the flat dies 2a and 2b by subjecting the male screw forming regions 7 and 7 and the deformed portion forming region 10 to electric discharge machining or the like on the same side surface of a single steel piece.

Next, the process of rolling a male screw on the peripheral surface of the cylindrical material W0 by the flat dies 2a and 2b of the rolling die 1 will be described with reference to FIGS. In the following, for the sake of convenience, it is assumed that the flat die 2a is set as a fixed side and the flat die 2b is set as a movable side so as to be movable in opposite directions and set in a rolling device (not shown).
As shown in the plan view of FIG. 5, the fixed-side flat die 2a and the movable-side flat die 2b are not shown in the opposite directions so that the molding surfaces 3a and 3b are symmetrical with respect to each other. Set in the rolling equipment. Next, between the biting parts 4 and 4 of the molding surfaces 3a and 3b, for example, a cylindrical material W0 made of stainless steel is fed with its biting direction with its axial direction perpendicular to the direction (right side in the figure). The part 4 is sandwiched from the start end side (preparation step).

  In this state, as shown by the black arrow in FIG. 5, the movable flat die 2b is brought closer to the fixed flat die 2a, and the material W0 is bitten by the molding surfaces 3a and 3b. 4 and 4 is sent between the parallel parts 5 and 5 while being sandwiched and rotated. As a result, the cylindrical peripheral surface of the material W0 is located in each of the pair of upper and lower male screw forming regions 10 extending from the biting portion 4 to the parallel portion 5, and gradually increases in height and size, and gradually increases in depth. Further, as shown in the right side of FIG. 5, the wide valley portion 9 becomes a material W1 in which a plurality of shallow and narrow screw valleys v1 are spirally engraved on both end sides in the axial direction. Note that a portion r having a substantially circular cross section at the beginning is located at the center in the axial direction of the material W1.

Subsequently, as shown in the plan view in FIG. 6, the material W1 is sandwiched and rotated between the parallel portions 5 and 5 of the molding surfaces 3a and 3b of the relatively moving flat dies 2a and 2b, and then escaped. Feed in the feeding direction on the part 9 side (molding step).
As a result, the thread valleys v1 of the material W1 are spirally engraved at both ends, and are positioned for each of the pair of upper and lower male screw forming regions 10 in the parallel portion 5, and the relief portion 6 is gradually higher toward the As shown on the right side of FIG. 6, a plurality of deeper and wider screw valleys v <b> 2 are spirally engraved on both end sides in the axial direction by the increasing peak portion 8 and the gradually deeper and wider valley portion 9. The intermediate material W2.
In addition, at the central portion of the intermediate material W2 in the axial direction, as will be described later, a plurality of arc-shaped portions 14, 15 projecting from the biting portion 4 to the parallel portion 5 of the deformed portion forming region 10, and Due to the flat surfaces 11 and 12 positioned between them, a plurality of flat surfaces h having slightly narrow widths are formed at symmetrical positions visually in the axial direction.

Further, as shown in the plan view in FIG. 7, the intermediate material W2 is sandwiched and rotated between the parallel portions 5 and 5 of the molding surfaces 3a and 3b of the relatively moving flat dies 2a and 2b. It sends to the escape part 9 side between the parallel parts 5 and 5 (molding step).
As a result, the thread valleys v1 of the intermediate material W2 are spirally engraved on both ends, and are positioned for each of the pair of upper and lower male screw forming regions 10 on the relief portion 6 side of the parallel portion 5, and the relief portions 6 are located. As shown on the left side of FIG. 7, a plurality of deep and wide screw valleys V are formed on both end sides in the axial direction by a gradually increasing and increasing peak portion 8 and a gradually deeper and wider valley portion 9. It becomes the bolt W3 with a deformed portion in which the thread M, which is located between the two and is high, is spirally engraved.
In addition, in the central part of the bolt W3 with a deformed portion, as will be described later, a plurality of arc-shaped portions 15 and 16 projecting from the parallel portion 5 to the escape portion 6 of the deformed portion forming region 10, and these Due to the flat surface 12 and the recessed surface 13 positioned therebetween, a deformed portion H1 having a substantially regular hexagonal cross section having a plurality of rectangular flat surfaces F symmetrically is formed.

In parallel with the male screw forming step, as shown in the upper part of FIG. 8, the deformed shape of the flat die 2a, 2b on the molding surfaces 3a, 3b that relatively move the central part (molded part) of the material W0. While being sandwiched and rotated between the biting parts 4 and 4 for each part molding region 10, it is sent to the parallel parts 5 and 5 side (preparation step).
The arc-shaped portions 14, 15, and 16 in the pair of deformed-portion forming regions 10, and the flat surfaces 11, 12 and the recessed surface 13 positioned between them are the same number and the same in line symmetry. Are provided with the same size. In addition, the material W0 receives a propulsive force in the feed direction with rotation during molding of the male screw.
As shown in the upper part of FIG. 8, the cylindrical material W0 is sandwiched between the biting portions 4 and 4 for each deformed portion forming region 10 on the forming surfaces 3a and 3b of the flat dies 2a and 2b, and rotates. It is sent between the parallel parts 5 and 5. During this time, the central portion of the material W0 in the axial direction is sandwiched between the relatively small arcuate portions 14 and 14 of the biting portions 4 and 4, facing each other, receiving a pair of pressures in a centripetal manner, and adjacent to each other. The pressure is released between the flat surfaces 11 and 11. However, between the biting portions 4 and 4 for each deformed portion forming region 10, no significant plastic deformation occurs in the central portion in the axial direction of the material W0.

  Next, the material W0 is fed between the parallel parts 5 and 5 for each of the deformed part molding regions 10 on the molding surfaces 3a and 3b of the relatively moving flat dies 2a and 2b and sent to the center side thereof while rotating. . As a result, as shown in the upper stage of FIG. 8 and the right end thereof, the central portion in the axial direction of the material W0 is between the relatively small arc-shaped portions 15 and 15 for each of the parallel portions 5 and 5 on the biting portion 4 side. Are opposed to each other, receive a pair of pressures in a centripetal manner, and the pressure is released between adjacent flat surfaces 12 and 12. At this time, the peripheral surface in the central portion of the material W0 subjected to the pair of pressures is formed with a plurality of narrow flat surfaces f1 symmetrically, and the material W1 in which a plurality of circumferential surfaces r are located between these surfaces. Become.

  Subsequently, as shown in the middle part of FIG. 8, the material W1 is sandwiched between the parallel parts 5 and 5 for each deformed part forming region 10 on the forming surfaces 3a and 3b of the relatively moving flat dies 2a and 2b, and While rotating, it sends in the feed direction on the escape portion 9 side (molding step). As a result, as shown in the middle stage of FIG. 8 and the right end thereof, the axial center portion of the material W1 is sandwiched between the relatively large arc-shaped portions 15 and 15 for each of the parallel portions 5 and 5. A pair of pressures are received relatively widely in a centripetal manner, and the pressure is released between the adjacent flat surfaces 12 and 12. At this time, a plurality of slightly wider flat surfaces f2 are formed symmetrically on the peripheral surface in the central portion of the material W1 that has received the pair of pressures, and the vicinity of the surface layer for each flat surface f2 is between these two surfaces. Since the surplus material enters the recessed space between the surfaces 12 and 12, the intermediate material W2 is left with a plurality of small circumferential surfaces r.

  Further, as shown in the lower part of FIG. 8, the intermediate material W2 is sandwiched between the parallel parts 5 and 5 for each of the deformed part forming regions 10 on the forming surfaces 3a and 3b of the relatively moving flat dies 2a and 2b, and While rotating, it is sent to the vicinity of the position immediately before the adjacent escape portions 9, 9 (molding step). As a result, as shown in the lower part of FIG. 8 and the right end thereof, the central part in the axial direction of the intermediate material W2 is sandwiched between the larger arcuate parts 15 and 15 for each of the parallel parts 5 and 5. A pair of pressures are received relatively widely in a centripetal manner, and the pressure is released between the adjacent flat surfaces 12 and 12. At this time, a plurality of wide flat surfaces F are formed symmetrically on the peripheral surface in the central portion of the intermediate material W2 that has received the pair of pressures, and between these flat surfaces F and F, The surplus in the vicinity of the surface layer for each flat surface F enters the recessed space between the surfaces 12 and 12 to form a plurality of ridge lines. Accordingly, the bolt W3 with a deformed portion having male screw portions on both ends in the axial direction and a deformed portion H1 having a substantially regular hexagonal shape (variant shape) between them and having six flat surfaces F on the outside. Is obtained.

The deformed portion bolt W3 having the deformed portion H1 is sandwiched and rotated between the relief portions 6 and 6 for each of the deformed portion forming regions 10 on the forming surfaces 3a and 3b of the flat dies 2a and 2b. After the flat surface F and the plurality of ridge portions are shaped or corrected to a more accurate shape by the plurality of arc-shaped portions 16 and the recessed surfaces 13 located between them, the clearances 6 and 6 are formed. It is discharged from the terminal to the outside.
As a result, as shown in FIG. 9, it has a pair of male screw portions S in which the screw thread M and the screw valley V are engraved in the same direction on both end sides in the axial direction, and there are six flat portions between them. A deformed portion-equipped bolt W3 having a deformed portion H1 having a substantially regular hexagonal cross section having the surface F is obtained.
According to the rolling die 1 and the rolling method of the deformed bolt W3 using the rolling die 1 as described above, the cylindrical material W0 is formed between the male thread forming regions 7 and 7 in the plurality of sets of peaks. By the plastic deformation by the part 8 and the valley part 9, the male thread part S composed of the thread M and the thread valley V is engraved (rolled) on at least one end side of the material W0.

In parallel with this, a plurality of arc-shaped portions 14 to 16 extending over the biting portion 4, the parallel portion 5, and the relief portion 6 in the deformed portion forming region 10, and a flat surface 11 positioned between them. 12 or the concave surface 13, the peripheral surface of the material W0 is caused by the pressure of the pair of arcuate portions 15 that press the material W0 in a centripetal manner and between the pair of flat surfaces 12 facing each other. Pressure release works alternately.
As a result, the peripheral surface of the material W0 other than the male screw S portion has a flat surface portion F that is recessed by receiving a pair of pressures facing each other and the flat surface portion F in the vicinity of the flat surface portion F with the release of the pressure and the release thereof. A ridge line portion is formed as the surplus thickness is unevenly deformed in the circumferential direction and is plastically deformed, and is formed into a deformed portion H1 having a non-circular cross section and a plurality of plane portions F symmetrically from the original circular cross section. .
Therefore, according to the rolling die 1 and the rolling method of the deformed portion bolt W3 using the rolling die 1, the deformed portion bolt W3 having both the male screw portion S and the deformed portion H1 having a non-circular cross section, The cylindrical material W0 can be molded accurately, reliably, quickly and inexpensively by a single rolling process.

FIG. 10 is a front view illustrating one molding surface 3a of the flat dies 2a and 2b, which is an application form of the flat dies 2a and 2b.
As shown in FIG. 10, the molding surface 3a (3b) of the flat die 2a (2b) includes a pair of upper and lower male thread molding regions 7 and 7 similar to the above, and a deformed portion molding region 10a located between them. I have. In the deformed portion forming region 10a, the heights and widths of the arc-shaped portions 14, 15, and 16 disposed in the biting portion 4, the parallel portion 5, and the relief portion 6 are compared with the deformed portion forming region 10 in the feed direction. The pitch p of the interval between them becomes progressively larger toward the feed direction.
Here, the material W0 is sandwiched between the biting portions 4 and 4 of the flat dies 2a and 2b in the same manner as described above. The molding behavior will be schematically described with reference to FIGS.

As shown from the left side to the right side of FIG. 11, the opposing arcuate parts are small in the height and width of each arcuate part 15 of the parallel parts 5 and 5 and the flat surface 12 is wide. Due to the pressure pressed by the 15 and 15, the four flat surfaces are formed at symmetrical positions on the material W 1, and the surplus surface layer near the flat surfaces is formed between the surfaces 12 and 12 facing each other. Uneven thickness in the dent space.
In the molding behavior, as the intermediate material W2x shown on the right side of FIG. 11 and the intermediate material W2y shown on the left side of FIG. The larger and flat surface 12 becomes progressively narrower and becomes more pronounced, and the four symmetrical flat surfaces begin to approach each other.

And in the parallel parts 5 and 5 just before the escape part 6, as shown in the right side of FIG. 12, the four flat bearing surfaces F by the pressure pushed between the opposing large arcuate parts 15 and 15 are almost outside. A deformed portion H2 having a substantially square cross section is formed, which is formed on the entire circumference and has a substantially right-angled ridgeline portion therebetween.
As a result, as shown in FIG. 13, there are male threaded portions S formed by a pair of male thread molding regions 7 and 7 at both ends, and a deformed portion H2 having a substantially square cross section between them (central portion). Can be formed.
The deformed bolts W3 and W3a can be formed by, for example, using the deformed portions H1 and H2 and screwing and fixing the male screw portion S on one end side into a female screw hole formed in the base plate. It can be used as a bolt.

FIG. 14 is a front view illustrating one molding surface 3a of the flat dies 2a and 2b in the rolling dies 1a of different forms.
As shown in FIG. 14, the molding surface 3a (3b) of the flat die 2a (2b) includes a male screw molding region 7 located above and a deformed portion molding region 10 located below the same. . By using the rolling die 1a, as shown in FIG. 15, the male thread portion S is rolled on one end side of the material W0, and the arc-shaped portion 14 of the deformed portion molding region 10 is formed on the other end side. ˜16 and the surfaces 11, 12 and the like, the deformed portion-equipped bolt W3b having the deformed portion H1 having a substantially regular hexagonal cross section.
The deformed portion forming region 10 of the forming surfaces 3a and 3b may be replaced with the deformed portion forming region 10a. According to such an embodiment, the male screw portion S is provided on one end side and the cross section is provided on the other end side. A bolt W3x with a deformed portion having a substantially square deformed portion H2 is obtained.
The bolts W3b and W3n with deformed parts can be used as stud bolts by making the bolt heads relatively small in diameter, or by welding the vicinity of the plane F of the deformed parts H1 and H2 to the base plate. Can also be used.

FIG. 16 is a front view illustrating one of the molding surfaces 3a of the flat dies 2a and 2b of the rolling die 1b of still another form.
As shown in FIG. 16, the molding surface 3a (3b) of the flat die 2a (2b) has a pair of male screw molding regions 7 and 7 in which the inclination directions of the peak portion 8 and the valley portion 9 are symmetrical, and these And a deformed portion molding region 10a similar to that described above. By using the rolling die 1b, as shown in FIG. 17, a pair of male screw portions S, S whose directions are opposite to the screw thread M and the screw valley V (reverse screw) on both ends of the material W0. Thus, a deformed portion-equipped bolt W3d having a deformed portion H2 having a substantially square cross section between them (center portion) is obtained.
The deformed portion forming region 10a of the forming surfaces 3a and 3b may be replaced with the deformed portion forming region 10, and according to such a configuration, there are a pair of male screw portions S and S in opposite directions on both ends. In addition, a deformed portion-equipped bolt W3y having a deformed portion H1 having a substantially regular hexagonal cross section between them is obtained. The bolts W3c and W3y with deformed portions are, for example, males of reverse screws at both ends between nuts having reverse female screw holes welded to opposite bracing ends such as a bracing of a building. The screw S can be screwed.

FIG. 18 is a front view illustrating one molding surface 3a of flat dies 2a and 2b in a rolling die 1c of another form.
As shown in FIG. 18, the molding surface 3a (3b) of the flat die 2a (2b) has a pair of male screw molding regions 7 and 7 having the same inclination direction of the crest 8 and the trough 9 between And a pair of upper and lower deformed portion molding regions 10a located in the above, and a pair of upper and lower flat surfaces 18, 18 located between them. In the pair of upper and lower deformed portion forming regions 10 a, the positions of the arc-shaped portions 14, 15, 16 are shifted by a half pitch p across the biting portion 4, the parallel portion 5, and the relief portion 6.
By using the rolling die 1c, as shown in FIG. 19, both ends of the material W0 are male threaded portions S, S, and a shaft portion G having a circular cross section between them (center portion), A deformed portion-equipped bolt W3e having a pair of deformed portions H2 having a substantially square cross section with the circumferential direction shifted by 45 degrees is adjacent in the axial direction.

  The deformed portion forming region 10a of the forming surfaces 3a and 3b may be replaced with the deformed portion forming region 10, and according to such a configuration, there are a pair of male screw portions S and S on both ends, and these In the meantime, through the shaft portion G, a deformed portion-equipped bolt W3z having a pair of deformed portions H1 having a substantially regular hexagonal cross section whose circumferential direction is deviated by 30 degrees is provided in the axial direction. Further, in the molding surfaces 3a and 3b, the male screw portions S that are opposite to each other are formed by having a pair of male screw molding regions 7 and 7 in which the inclination directions of the peaks 8 and valleys 9 are symmetrical. It is also possible to obtain deformed bolts W3e and W3z having

FIG. 20 is a plan view showing an outline of a pair of circular dies 2c and 2d in a rolling die 1d having a different form.
As shown in FIG. 20, the circular dies 2c and 2d have a substantially circular shape in plan view and a substantially cylindrical shape as a whole, and a cylindrical molding surface similar to the above along the circumferential direction of the peripheral surfaces thereof. 3a and 3b are provided in the order of the biting part 4, the parallel part 5, and the escape part 6. In the cylindrical molding surfaces 3a and 3b, the male screw molding region 7 and the deformed portion molding regions 10 and 10a are arranged in any pattern shown in the rolling dies 1 and 1a to 1c. In the circular dies 2c and 2d, notches having an acute cross section (not shown) are opened between the parallel portion 5 and the relief portion 6, respectively.
As shown in FIG. 20, a cylindrical material W0 is inserted into the gap between the biting portions 4 and 4 of the circular dies 2c and 2d (preparation step), and the circular dies 2c and 2d are rotated in synchronization in the same direction. Then, the pair of biting portions 4, parallel portions 5, and escape portions 6 are brought into contact with the peripheral surface of the material W0 in sequence while being sequentially pressed (molding step). As a result, any of the deformed bolts W3, W3a to W3e, W3x to W3z can be formed according to the pattern of the molding surfaces 3a and 3b.

The present invention is not limited to the embodiments described above.
For example, by adjusting the pitch between the plurality of arc-shaped portions in the deformed portion forming region and the protruding pattern of the cross-sections thereof, the odd-shaped cross-section having a pair of parallel flat surfaces or the cross-section substantially normal It is also possible to form a deformed portion having a triangular shape or a substantially regular polygon having a substantially regular octagon or more in cross section at the central portion or one end side of the bolt.
Further, the cross-sectional shape of the arc-shaped portion in the deformed portion forming region is not limited to the arc shape with one radius, but is a circle such as a substantially semi-elliptical shape or a cycloid curve with a plurality of curves with a plurality of radii combined. It may be an arc shape.
Further, the elongated flat surface 18 may be disposed between the male screw forming region 7 and the deformed portion forming regions 10 and 10a on the forming surfaces 3 and 3b of the rolling dies 1 and 1a and 1b.

  In the present invention, a bolt (screw) with a deformed portion such as a stud bolt having male threaded portions at both ends and a non-circular shaped cross section between them is used with a single rolling device, and With a single rolling process, it is possible to form accurately, reliably, quickly and at a low cost.

1, 1a to 1d ...... Rolling dies 2a, 2b ............ Flat dies 2c, 2d ............ Circular dies 3a, 3b ............ Molding surface 4 ............ ……………… Bits 5 ………………………… Parallel 6 ………………………… Escape 7 ………………………… Male thread forming area 8 ………………………… Mountain 9 ………………………… Tanibe 10, 10a …………… Deformation part forming region 14, 15, 16 ……… Arc-shaped part W0 ………………………… Materials W3, W3a to W3e… Bolts with deformed parts H1, H2 ……………… Shaped parts

Claims (5)

A male thread molding region consisting of a plurality of sets of crests and troughs that are located on a pair of opposed molding surfaces and are parallel to each other and inclined with respect to the feed direction of the material,
A non-circular shaped part forming region having a non-circular cross section, which is located in parallel with the male screw forming part on the pair of forming surfaces, and has a plurality of arcuate parts protruding at equal intervals along the feed direction of the material, With
The plurality of arc-shaped portions in the deformed portion forming region are provided so that the cross-section of the arc-shaped portion sequentially increases in the order of the biting portion, the parallel portion, and the relief portion of the forming region,
A rolling die characterized by that. The male screw forming region and the deformed portion forming region are disposed adjacent to or separated from each other on the facing molding surfaces of a pair of flat dies, or are formed on the cylindrical molding surfaces of a pair of circular dies. Arranged adjacent to or away from each other in the axial direction,
The rolling die according to claim 1. The male screw forming region is arranged in such a manner that a pair is arranged adjacent to or parallel to both sides of the deformed portion forming region orthogonal to the feed direction of the material, and a ridge for each pair of male screw forming regions. The part and the valley are in the same direction as each other or in opposite directions.
The rolling die according to claim 1 or 2, characterized by the above. Using the rolling die according to any one of claims 1 to 3,
A preparation step of sandwiching a cylindrical material so that its axial direction is orthogonal to the feed direction and rotatable between the biting portions facing a pair of molding surfaces in the rolling die, and
By moving or rotating the pair of molding surfaces in directions opposite to each other, the material is arranged in the order between the biting parts facing each other, between the parallel parts, and between the escape parts. Including a molding step of sandwiching and rotating
A method of rolling a bolt with a deformed portion, characterized in that. In the molding step, the part to be molded of the material fed while rotating between the pair of opposed deformed portion molding regions is a substantially regular polygon having a non-circular cross section, or a substantially oval shape. The deformed part is molded,
The method for rolling a bolt with a deformed portion according to claim 4.

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