TWI642496B - Form-rolling die structure of double threaded body, adjustment die structure of double threaded body, form-rolling method for double threaded body, adjustment method for double threaded body - Google Patents

Abstract

In the present invention, the double-threaded body D is rolled using a mold member having a rigid surface that is crimped to the thread blank material B and relatively displaced. The mold member has a double-threaded portion forming region U which is formed in a normal parallel direction of the hypothetical surface obtained between the outermost portions of the joint surface to form a substantially parallelogram shape, and a plurality of concave surfaces from the hypothetical surface are arranged along the direction of the relative displacement. a plurality of recesses. Further, the mold member may have a double-threaded portion adjustment region N which is disposed on the upstream side and/or the downstream side of the double-threaded portion forming region U, and is inclined at an angle corresponding to the angle of the double-threaded portion forming region U to form An adjustment valley that is recessed and recessed on a hypothetical surface. Thereby, when the double-threaded body is formed, the rotation failure of the cylindrical thread blank material is reduced, and a precise double-threaded body can be mass-produced.

Description

Roll forming die structure of double threaded body, adjustment die structure of double threaded body, roll forming method of double threaded body, and adjustment method of double threaded body

The present invention relates to a rolling die structure for rolling a double-threaded body having a right-threaded portion and a left-threaded portion in the same region of the axial direction of the screw portion by rolling, efficiently, accurately, and stably.

In the past, in the case of a male thread having a thread portion of only the right or left thread by rolling, it is usually a plurality of rigid plates, rigid cylinders or rigid cylinders having a plurality of strips on the surface. The mold part, which is also called the metal cylindrical rod-shaped thread blank material of the blank, causes the thread blank material to be displaced relative to the mold part, and plastically deforms the surface of the thread blank material to form a thread or a thread Thread groove. The strips formed on the mold member are formed in a desired shape in a cross section thereof, for example, forming a substantially triangular shape, and are formed in a state of having an elevation angle substantially parallel to each other.

The male threaded body has a double-threaded body of a right-threaded portion and a left-threaded portion in the same region in the axial direction of the threaded portion of the male threaded body, and is tried by rolling production (refer to Japanese Laid-Open Patent Publication No. 2013-43183) Bulletin).

According to Japanese Laid-Open Patent Publication No. 2013-43183, the shape of the parallelogram recessed in the double-threaded strip portion recessed in the mold member is optimized, and the shape of the shaft after rolling is relatively stable, and the strip portion can be accurately formed. . In addition, in the future, in response to the expansion of demand, it is expected to further increase mass production, and it is necessary to increase the mass production technology that is commonly used.

SUMMARY OF THE INVENTION The object of the present invention is to achieve a high degree of mass production technology which is commonly used in response to the demand as set forth above, that is, to provide a reduction in the rotation of a cylindrical thread blank material when forming a double threaded body, and to produce a precise double A die structure and a rolling method for a double-thread rolling of a threaded body.

In order to solve the above problems, the double-thread rolling die structure is characterized in that it has a mold member having a rigid surface that is pressed against the thread blank material and is relatively displaced, and the mold member has a double thread portion. a region in which a substantially parallelogram shape is formed as viewed in a normal direction of a hypothetical surface obtained by joining the outermost surfaces of the surfaces, and a plurality of recesses recessed from the hypothetical surface are arranged along the direction of the relative displacement; And the double-threaded portion adjustment region is disposed on the upstream side and/or the downstream side in the direction of the relative displacement of the double-threaded portion forming region, and is inclined at an angle corresponding to the angle of the double-threaded portion forming region. The above-mentioned assumption is that the surface is extended in a strip shape and the valley for adjustment is recessed from the assumed surface.

According to the above aspect, the double-threaded portion adjustment region includes a first adjustment portion that is inclined so as to correspond to a degree of the angle of the single thread, and is disposed corresponding to the one formed in the double-thread portion forming region. a first groove for adjusting the single thread; and a second adjusting portion disposed on a downstream side of the direction in which the first adjusting portion is relatively displaced, and inclined at a degree corresponding to the rising angle of the other single thread And arranging the second aforementioned adjustment valley portion corresponding to the other single thread formed in the double thread portion forming region.

The above-described means is characterized in that the adjustment valley portion in the double-thread portion adjustment region is formed to be continuous with the concave portion in the double-thread portion forming region.

In the above-described means, the double-threaded portion forming region has a maximum dimension in the direction in which the plurality of recessed portions are relatively displaced, and is set to be smaller in order from the upstream side toward the downstream side.

In the above-described double-threaded portion forming region, the distance between the central axis of the thread blank material and the assumed surface is set to be smaller from the upstream side of the thread blank material relative to the displacement side toward the downstream side. section.

According to the above aspect, the mold member includes: a region that gradually approaches the axial center of the thread blank material along a direction of the relative displacement in a hypothetical surface obtained by joining the outermost surfaces of the surfaces; A precursor processing region from the region where the axis gradually deviates.

According to the above aspect, at least a part of the precursor processing region in the mold member is present on the upstream side of the threaded blank material when the thread blank material is relatively displaced.

The above-described means is characterized in that the mold member has a single thread portion forming region in a state in which the double-thread portion forming region is deviated in the axial direction of the thread blank material. In the abutting arrangement, the direction of the relative displacement is inclined at an angle of elevation, and is disposed in the valley portion of the assumed surface which extends in a strip shape and is recessed from the assumed surface.

In order to solve the above problems, the double-thread adjusting mold structure is characterized in that it is provided with an adjusting mold member having a rigid surface that is crimped and relatively displaced with respect to a thread blank material forming a double-threaded region; The mold member has a double-threaded portion adjustment region which is inclined at an angle corresponding to the angle of the double-threaded region of the thread blank material, and is disposed on a hypothetical surface obtained by joining the outermost portions of the surface, and extends in a strip shape This assumes that the surface recess is adjusted by the valley.

According to the above aspect, the double-threaded portion adjustment region includes: a first adjustment portion that is inclined at an angle corresponding to a single one of the single threads, and is disposed in correspondence with the double-threaded region of the thread blank material The first adjustment valley portion of the single thread and the second adjustment portion are disposed on the downstream side of the first adjustment portion in the direction of the relative displacement, and correspond to the degree of the angle of the other single thread Tilting, and arranging the second aforementioned adjustment valley corresponding to the other single thread formed by the double-threaded region.

In order to solve the above problems, the double-thread rolling method is characterized in that, when the mold member having the rigid surface is relatively displaced with respect to the thread blank material, the mold member is provided with a double-thread portion forming region, which is tied Forming a substantially parallelogram shape by viewing a normal direction of a hypothetical surface obtained by joining the outermost surfaces of the surfaces, and arranging a plurality of recesses recessed from the hypothetical surface along the direction of the relative displacement; and adjusting the double thread portion The region is disposed on the upstream side and/or the downstream side in the direction of the relative displacement of the double-threaded portion forming region, and is inclined at an angle corresponding to the rising angle of the double-threaded portion forming region, and is disposed on the assumed surface band The double-threaded body is rolled by the mold member being pressed against the thread blank material and relatively displaced by the adjustment of the valley portion from the assumed surface.

In order to solve the above problem, the double thread adjusting method is characterized in that, when the adjusting mold member having the rigid surface is relatively displaced with respect to the thread blank material forming the double-threaded region, the adjusting mold member has a double thread portion. An adjustment region which is inclined at an angle corresponding to an angle of the aforementioned double-threaded region of the threaded blank material, and which is disposed in a belt-like extension obtained by joining the outermost portions of the surfaces and adjusted from the assumed surface recess In the manner of the valley portion, the double-threaded region is adjusted by crimping and relatively displacing the double-threaded region of the thread blank material with the adjusting mold member.

According to the present invention, when the double-threaded body is formed, the rotation failure of the cylindrical thread blank material is reduced, and the excellent effect of the precise double-threaded body can be produced in a large amount.

10‧‧‧Mold parts

12‧‧‧ Round mold parts

13‧‧‧Circular mold parts

20‧‧‧Rigid surface

22‧‧‧ assumed surface

30‧‧‧ recess

31, 32‧‧‧ corner

33‧‧‧ Periphery

34‧‧‧The deepest part

35‧‧‧ bottom

36‧‧‧one side

37‧‧‧The other side is opposite

50‧‧‧ Valley Department

61‧‧‧First adjustment with the valley

62‧‧‧Second adjustment valley

B‧‧‧Thread blank material

BJ‧‧‧ single thread corresponding area

BU‧‧‧Double thread corresponding area

D‧‧‧Dual thread

D‧‧‧ interval

d _R ‧‧‧ Valley Trail

E, E1‧‧‧Axis

F‧‧‧Diagonal distance

J‧‧‧Single thread forming area

J1, J2, J3‧‧‧ parts

K‧‧‧Cylinder forming area

L1, L2, L3‧‧‧ distance

M‧‧‧ thread teeth

MA‧‧‧ highest top

MX‧‧‧ intersection

PQ‧‧‧ deformation spacing

PU‧‧‧ arrangement spacing

PX‧‧‧ grid spacing

P‧‧‧ recessed spacing

Q‧‧‧Precursor processing area

Q1‧‧‧ close area

Q2‧‧‧ Deviation from the area

S1, S2‧‧‧ total sectional area

SP‧‧‧Separated area

T1, T2, T3‧‧‧ arrangement spacing

U‧‧‧Dual thread forming area

V‧‧ ‧ neck

W1, W2, W3‧‧‧ maximum size

N1‧‧‧First Adjustment Department

N2‧‧‧Second Adjustment Department

ZG‧‧ arrow

The first figure shows a die structure and a rolling method for double-thread rolling used in an embodiment of the present invention. The summary is that (A) shows flat die rolling, (B) shows rolling rolling, (C) A diagram showing the planetary rolling.

The second (A) diagram shows a front view of the mold part of the mold construction.

The second (B) diagram shows a side view of the mold part of the mold construction.

The second (C) diagram shows an exploded view of the mold part of the mold construction.

Fig. 3(A) is a front view showing the arrangement of the concave portions of the double-threaded portion forming region in the mold structure, and (B) showing the deformation process of the thread blank material in the double-threaded portion forming region, (C) A cross-sectional view showing the cross-sectional shape of the concave portion enlarged.

The fourth figure is a front view showing the arrangement pitch of the concave portions of the double-threaded portion forming region in the mold configuration.

The fifth diagram (A) shows an application example of rolling rolling, and (B) shows an application example of planetary rolling.

Fig. 6(A) is a view showing the positional relationship between the concave portion in the mold structure and the adjustment valley portion in the double-threaded portion forming region, and (B) showing the state in which the concave portion and the adjustment valley portion in the mold structure are continuous. The front view, (C), is a conceptual diagram showing the thickness movement of the thread blank material rolled by the mold configuration.

7(A) to (C) are side views showing a process of processing a thread blank material by a precursor machining region in the mold structure, and (D) showing a concavo-convex shape having a trapezoidal cross section or a zigzag shape.

Fig. 8(A) is a side view showing a part of the double-threaded body enlarged, (B) is a sectional view showing a sectional area of the highest top of the thread of the double-threaded area, and (C) is a bottom view of the double-threaded body.

The ninth diagram (A) is a side view showing a part of the double-threaded body enlarged, (B) is a sectional view showing a sectional area of the thread intersection of the double-threaded area, and (C) is a bottom view of the double-threaded body.

(A) and (B) are front views showing other configuration examples of the mold structure for double-thread rolling in the embodiment of the present invention.

Fig. 11 is a front view showing another configuration example of the mold structure for double-thread rolling in the embodiment of the present invention.

Fig. 12(A) is a front view and a side view showing another configuration example of the mold structure for double-thread rolling in the embodiment of the present invention, and (B) shows the side of the example of the double-threaded body D which is rolled thereby. The views, (C) and (D) show a front view of another configuration example of the thread blank material B.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a mold structure for a double-thread rolling according to an embodiment of the present invention will be described. The mold structure for double-thread rolling is press-bonded to the cylindrical thread blank material B, and is displaced in a direction orthogonal to the axial direction of the thread blank material B, and the surface of the thread blank material B is deformed. The double-threaded body D having the right-hand thread portion and the left-thread portion in the same region in the axial direction is rolled.

The rolling method includes: a so-called flat die rolling using two plate-shaped mold members 10 as shown in the first (A); two or more cylindrical or cylindrical types shown in the first (B) The so-called rolling rolling used for the round mold members 12 and 12; and the first circular arc mold member 13 shown in the first (C) diagram, and the other cylindrical or cylindrical circular mold member 12 is rolled. The so-called planetary rolling and the like. Hereinafter, the present embodiment specifically describes the case of the flat mold structure, but the present invention can also be applied to not illustrated in All other rolling methods of this.

The rolling die structure of the present embodiment includes two or more die members 10 that are pressed against the thread blank material B, and each of the die members 10 has a rigid surface 20. The two or more mold members 10 are crimped to the thread blank material B, and the rigid surfaces 20 of each other are relatively displaced, and the thread blank material B is rotated on the rigid surface 20.

As shown in FIG. 2A, the rigid surface 20 of the mold member 10 has a plurality of independently aligned rows in the hypothetical surface 22 obtained by joining the outermost portion of the rigid surface 20 (the portion closest to the thread blank material B). The double threaded portion having the recess 30 forms a region U. The concave portion 30 of the double-threaded portion forming region U is formed in a substantially parallelogram shape as viewed in the normal direction, and is recessed from the hypothetical surface 22 as shown in FIG. Here, it is assumed that the surface 22 is set to be flat in the case of the plate-shaped mold member 10, and it is preferably set to a cylindrical shape in the case of a circular die form, and to be set as a partial cylindrical surface in the case of an arc-shaped mold form. (Arc surface) shape.

Each of the recesses 30 is formed in a substantially parallelogram shape when viewed in the normal direction of the surface 22, and is preferably formed into a rough diamond shape. By setting it as a rough diamond shape in this way, the pitch of each thread in the right-threaded part and the left-thread part of the rolling double-threaded body D can be equal to each other.

Among the four corner-corresponding portions of the substantially parallelogram shape when the concave portions 30 are viewed in the normal direction, the two or more corner portions 31 and 31 are formed in a circle in the normal direction as shown in the third (A) diagram. In the present embodiment, all of the corner portions 31, 31, 32, and 32 of the four corner-corresponding portions of the substantially parallelogram shape are formed into a circle. Further, the two or more corner portions 31, 31 should be set to be diagonal positions, and it is preferable to set the two or more corner portions 31, 31 to be in the direction in which the thread blank material B is rotated, that is, in the opposite direction. The diagonal position of the displacement direction is such that the chips which occur in the event of rolling are likely to flow out of the recess 30 when they are relatively displaced.

Further, the concave portion 30 is formed with a hole shape having a hypothetical quadrangular pyramid shape in which the opening surface is a constituent surface, and the center top portion of the outline quadrangular pyramid shape constitutes the deepest portion 34 of the concave portion 30. The deepest portion 34 of the recess 30 is preferably formed into a shape having a substantially flat bottom portion 35. In this way, the bottom portion 35 is enlarged, and in the event that the chip occurs, the chip is not clogged and is easy to flow out, and the highest top portion of the thread M of the double-threaded body D does not form an acute angle in the direction perpendicular to the axis of the double-threaded body D, so that the female thread body can be double-paired. The stability of the threaded body D when screwed is improved. In addition, the precision of the product of the double-threaded body D obtained by mass production can be made remarkable. improve.

As shown in the third (A) diagram, the arrangement pitches T1, T2, T3, ... in the direction in which the concave portions 30 are displaced relative to each other in the double-threaded portion forming region U are set to the upstream side from the relative displacement of the thread blank material B. It becomes smaller toward the downstream side. That is, it becomes T1>T2>T3>. As shown in the third (B) diagram, when the thread blank material B is rotated from the upstream to the downstream in the double-thread portion forming region U, the shaft portion E from which the thread M is removed is gradually formed. The outer circumferential distance of the shaft portion E (assuming a perfect circle, the diameter × π) gradually decreases toward the downstream, and finally becomes a substantially perfect circular shape. Therefore, since the rotational distance traveled by the one-time rotation of the thread blank material B is also gradually decreased toward the downstream, the arrangement pitches T1, T2, T3 of the direction in which the concave portions 30 are relatively displaced are reduced in advance by this. At this time, the concave portion 30 can be crimped to the thread blank material B in rotation at the same phase at any time, and the shape accuracy of the thread M can be remarkably improved. In addition, here, the entire area of the double-threaded portion forming region U is exemplified, and the arrangement pitches T1, T2, T3, ... are gradually reduced. However, the localized region of the relative displacement direction may be narrowed to gradually reduce the arrangement pitch T1. T2, T3...

As shown in the third (B) diagram, in the rolling using the rolling die structure, the distance between the shaft portion E1 of the thread blank material B in the double-threaded portion forming region U and the hypothetical surface 22 is preferably L1, L2, L3. . . . from the upstream side of the relative displacement of the thread blank material B toward the downstream side becomes smaller. That is, it becomes L1>L2>L3>. In this way, since the thread blank material B can be compressed in such a manner that the diameter of the shaft portion E of the thread blank material B gradually decreases toward the downstream, the arrangement pitches T1, T2, T3 of the direction of the relative displacement of the recesses 30 can be reduced. The multiplication effect further improves the shape accuracy of the thread M.

Further, the third (A) diagram exemplifies that the maximum dimension W of the relative displacement direction is constant for all the concave portions 30. However, as shown in the fourth figure, for example, the plurality of concave portions 30 in the double-threaded portion forming region U are relatively displaced. The maximum dimensions W1, W2, W3, ... in the direction are preferably set to be gradually smaller in order from the upstream side to the downstream side. That is to become W1>W2>W3>. The final shape of the thread M is similar to the recess 30 on the most downstream side of the double-threaded portion forming region U. Further, since the upstream side has larger arrangement intervals T1, T2, T3, ... than the most downstream side and has a margin in space, the maximum size W1, W2, W3, ... of the set recess 30 can be increased. Since the maximum size W1, W2, W3, ... of the recess 30 can increase the plastic deformation amount of the thread blank material B, the concave portion 30 on the upstream side can be plastically deformed as early as possible, and approach the final thread as it enters the downstream side. The shape of the tooth M is rolled.

As shown in the third (C) diagram, the recesses 30 are along the normal to the hypothetical surface 22 In the cross-sectional shape of the direction, the peripheral edge portion 33 is formed into a circle by, for example, R machining, and a circle is formed around the periphery 33 of the substantially parallelogram shape. Thus, by forming the circumference of the peripheral edge portion 33 of the recessed portion 30 over the entire circumference of the peripheral edge 33, it is possible to prevent the surface of the mold member 10 from being improperly contacted with the thread blank material B during rolling, and cutting from the thread blank material B to cause chipping. occur. Further, the present invention is not limited thereto, and for example, a trapezoidal shape may be formed as shown in the third (D) diagram, or a V shape may be formed.

As shown in the third (A) diagram, the concave portion 30 of the substantially parallelogram shape when viewed from the normal direction of the surface 22 is a diagonal distance W of at least one of the diagonal lines, and the radius of the thread blank material B. When R0 is set and the pi is π, it is set to 2πR0 or less. When the valley diameter of the double-threaded body D obtained by the practice of the present invention is d _R (refer to the eighth drawing), at least one of the diagonal lines W of the substantially parallelogram forming the concave portion 30 is preferably set. It is πd _R or less. It is preferable that the diagonal distance of the diagonal line parallel to the relative displacement direction among the diagonal lines of the substantially parallelogram forming the concave portion 30 is set to be πd _R or less. By setting in this way, not only the pitch of the right-threaded portion and the left-threaded portion can be set equal, and an accurate double-threaded body D can be obtained.

Further, as shown in the third (A) diagram, the opening of the recess 30 is a diagonal distance of a substantially parallelogram when viewed in the normal direction of the surface 22, and the diagonal distance of the relative displacement direction is preferred. The W setting is long, and the diagonal distance of the other side is preferably set to be shorter than the diagonal distance F of the orthogonal direction of the relative displacement direction. Further, in the concave portion 30, the volume of the concave portion 30 is v, the pi is π, and the concave pitch of the concave portion 30 in the direction orthogonal to the relative displacement direction of the mold member 10 is p, and the valley of the double-threaded body D When the diameter is set to d _R (refer to the eighth figure), when the depth of the deepest portion 34 of the concave portion 30 is h, it is preferable to define the volume v of the concave portion 30 here by πpd _R h/7≦v≦πpd _R h/5 . The scope of the way. When the setting is smaller than the range, the thread M is too thin, too small, and the strength is insufficient, or the double-threaded body D of the male thread obtained by the practice of the present invention is excessively screwed when the female thread body is screwed, and the molding is excessively large. On the other hand, when the setting is larger than the range, the thread M is too thick and too large, and the double threaded body D of the male thread obtained by the practice of the present invention has a small clearance when the female thread is screwed, and the screwing is difficult or cannot be screwed. , or it is difficult to accurately roll the thread M.

Therefore, when the size of the concave portion 30 is changed as shown in the fourth figure, it is preferable to change it within a range satisfying the condition of the above-described volume v.

Returning to Figure 2A, the rigid surface of the mold member 10 is attached to the outermost surface of the rigid surface. The hypothetical surface 22 obtained between (the portion closest to the thread blank material B) has a double thread portion adjustment region N therein. The double-threaded portion adjustment region N is disposed on the downstream side of the double-threaded portion forming region U in the relative displacement direction to correct the shape of the double-threaded region formed in the thread blank material B (or the double-threaded body D). Here, the case where the double-threaded portion adjustment region N is disposed so as to be connected to the double-threaded portion forming region U of the mold member 10 may be used separately from the mold member 10 to form a modified double-threaded portion. The mold member (double thread portion adjustment structure) uses the double thread portion adjustment region N. Therefore, the method of forming the double-threaded region in the thread blank material B is not limited to rolling, and various methods can also be employed.

In the double-threaded portion adjustment region N, the adjustment valley portions 61 and 62 which are disposed in a strip shape on the hypothetical surface 22 and which are recessed from the hypothetical surface 22 are disposed obliquely at an angle corresponding to the angle of the double-thread portion forming region U. Further, the double screw portion adjustment region N has a first adjustment portion N1 and a second adjustment portion N2. The first adjustment portion N1 obliquely arranges the first adjustment valley portion 61 corresponding to the one single thread of the double-threaded region with an angle corresponding to the rising angle of one single thread. The second adjustment portion N2 is disposed on the downstream side of the first adjustment portion N1 in the direction of the displacement direction, and is disposed at a second angle corresponding to the other single thread of the double-threaded region at an angle corresponding to the angle of the other single thread. Use the valley 62. That is, as shown in the pattern of the sixth (A), the inclination angle of one side of the substantially parallelogram of the concave portion 30 of the double-threaded portion forming region U is inclined to the inclination angle of the first adjustment valley portion 61 (equivalent to The degree of elevation of one of the single threads is the same, and the inclination angle of the other opposite side 37 of the substantially parallelogram of the recess 30 coincides with the inclination angle of the second adjustment valley 62 (corresponding to the degree of elevation of the other single thread).

Further, as shown in the sixth (B) diagram, the first adjustment valley portion 61 is formed to be continuous with the concave portion 50 located in the double-thread portion forming region U on the upstream side. Specifically, the first adjustment valley portion 61 extends the concave portion 50 such that the diagonal line connecting the one diagonal portion 32, 32 in the connecting axial direction is divided into two half-regions 30A. Therefore, by the rolling of the concave portion 50 of the double-threaded portion forming region U, the thread of the parallelogram formed on the thread blank material B (refer to the thread M of the double-threaded body D of the ninth figure) is continuously inserted into the double thread. The first adjustment valley portion 61 of the first adjustment portion N1 of the portion adjustment region N is further rolled without causing a phase deviation. Then, the thread of the thread blank material B is fitted into the second adjustment valley portion 62 of the second adjustment portion N2, and further rolling is performed without causing a phase deviation.

As shown in the eighth (B) and ninth (B) figures, in the double thread D, the right thread and The feature of the double-threaded area formed by the overlapping of the left-hand thread is a total cross-sectional area S1 of the thread-only tooth M having one of the 180-degree phase difference to the highest top MA of the thread M, M (refer to the eighth (B) diagram); The total cross-sectional area S2 (refer to the ninth (B)) of the thread M of the intersection portion MX intersecting the thread M and M with respect to the highest top MA is substantially different from each other in the circumferential direction by 90 degrees. That is, the rolling of the double-threaded body D deforms the thread blank material B in such a manner that the shaft portion E is approximately a perfect circle, but the thread M around it must be 90 degrees apart from the volume near the highest top MA. The volume near the intersection MX is deformed in a different manner.

Therefore, in the step of rolling the concave portion 50 of the double-threaded portion forming region U, it is preferable to reduce the thickness portion (the portion pressed by rolling) in order to obtain the thread M near the intersection portion MX. Move to the near top of the top top MA to expand the topmost MA (increase thickness). However, as is understood from FIG. 2A and the like, since the plurality of concave portions 50 formed in the double-thread portion forming region U are all independently formed in a honeycomb shape, the thickness movement between the plurality of adjacent concave portions 50 adversely causes an obstacle. Therefore, sometimes the material flow is difficult due to the material of the thread blank material B, which may cause the thread M to reduce the thickness at the near side of the intersection MX and the balance unevenness at the near side of the highest top MA.

For example, when the phase Z of the side of the mold member 10 (refer to the sixth (B) diagram) causes the thickness of the vicinity of the intersection MX of the thread M in the arrow Z direction (refer to the sixth (C) diagram), the shaft is insufficient. The portion E does not form a perfect circle (see a broken line), but has an elliptical shape in which the intersection portion MX side has a long axis. Similarly, due to the phase G of the mold member 10 side (refer to the sixth (B) diagram), when the thickness of the near top MA of the thread M is increased in the direction of the arrow G (refer to the sixth (C) diagram), the thread is insufficient. The height of the tooth M is insufficient for the ideal shape of the highest top MA (refer to the dotted line). In addition, when a general thread (single thread) is rolled, it is not easy to cause insufficient flow of the thread blank material.

Therefore, in the present embodiment, in the double-threaded portion forming region U, the thread blank material B is formed into a double-threaded region in which two single threads are different in the spiral direction, and then the thread blank material B is brought into the double-thread portion adjustment. The region N is additionally rolled by the first adjustment valley portion 61 which is substantially identical to the one single thread rolling application, and thereafter, the second adjustment valley portion which is substantially identical to the rolling application of the other single thread is further used. 62 additional rolling. As shown in the second A diagram and the sixth diagram (B), since the first and second adjustment valley portions 61 and 62 extend in a strip shape, the thickness of the thread blank material B is easily moved in the extending direction. As a result, as indicated by the arrow ZG of the sixth (C) diagram, by the above addition In the rolling, the thickness reduction portion of the vicinity of the intersection MX of the thread M in the direction of the arrow Z flows in the direction of the arrow G in the vicinity of the highest top MA, and the thickness can be increased. As a result, the top portion MA of the thread M can be sufficiently expanded while the shaft portion E is approximately a perfect circle.

In particular, the double screw portion adjustment region N of the present embodiment includes the first adjustment portion N1 and the second adjustment portion N2. In the rolling of the first adjustment portion N1, the thread M formed on the thread blank material B slightly moves in the extending direction of the first adjustment valley portion 61 (one single thread direction), and is deformed in this direction to possibly generate error. Further, the second adjustment portion N2 is rolled by the second adjustment portion N2 so as to extend in the extending direction (the other single thread direction) of the second adjustment valley portion 62 that intersects with the extending direction of the first adjustment valley portion 61. Therefore, the error generated by the first adjustment unit N1 can be restored. Further, it is preferable that the first adjustment portion N1 is further disposed on the downstream side of the second adjustment portion N2, and the second double-thread portion formation region is disposed on the downstream side of the double-thread portion adjustment region N, and the thread shape is further finely adjusted. However, there is no special illustration here.

Further, as shown in FIG. 2C, in the mold member 10, the boundary between the double-threaded portion forming region U and the double-threaded portion adjusting region N can be divided. In the mold member 10, the length of the double-threaded portion forming region U and the double-threaded portion adjusting region N in the relative displacement direction can be changed independently of each other. Further, the mold member 10 may be further divided into a part piece at the boundary in the axial direction of the double-threaded portion adjustment region N, but is not particularly illustrated here. In this way, for example, a plurality of component pieces of the double-threaded portion adjustment region N having a shaft width of 5 mm are provided in advance, and the axial width of the double-threaded portion adjustment region N can be arbitrarily adjusted in units of 5 mm depending on the number of pieces of the component pieces.

The hypothetical surface 22 obtained by the mold member 10 between the outermost portion of the rigid surface 20 (the portion closest to the thread blank material B) has a precursor processing region Q. The precursor processing region Q is processed, for example, in an elliptical cross-sectional shape or a front-sectional cross-sectional shape (hereinafter referred to as a rough elliptical shape) such as an oblong shape, and is formed in the continuous double-thread portion forming region U. In order to form a shape that is easy to form a double-threaded portion. In particular, in the precursor processing region Q, the cross-sectional shape of the thread blank material B is processed into a substantially elliptical shape.

As shown in the seventh figure, the precursor processing region Q is gradually approached to the vicinity of the axis E1 of the thread blank material B in the direction of relative displacement with the thread blank material B, assuming that the surface 122 itself maintains the surface state. Q1, a departure from the region Q2 that gradually deviates from the axis E1. Therefore, as in the first As shown in the seventh (A) diagram, the thread blank material B which has been in the shape of a circular cross section is subjected to a compression process in the same direction in the vicinity of the region Q1, and finally has a long axis and a short phase as shown in the seventh (C) diagram. The section of the shaft is not circular. Here, the case where the approaching region Q1 and the departure region Q2 are curved surfaces is exemplified here, but the present invention is not limited thereto. For example, as shown in the seventh (D) diagram, the cross section may be a trapezoidal concavity or a jagged unevenness.

As shown in FIG. 2A, at least a part of the precursor processing region Q in the mold member 10 is present on the upstream side of the double-threaded portion forming region U when the thread blank material B is relatively displaced. The precursor machining region Q and the double thread portion forming region U should be independently configured. Thus, before the thread blank material B enters the double-thread portion forming region U, the thread blank material B can be previously formed into a substantially elliptical shape in the precursor machining region Q. Of course, part or all of the precursor processing region Q may also overlap with the double-thread portion forming region U. When repeated, the thread blank material B is machined into an ellipse and also forms a thread.

In the double-thread portion forming region U, the deformation pitch PQ between the proximity region Q1 and the deviation region Q2 in the precursor machining region Q is set to the arrangement pitch PU of the plurality of concave portions 30 arranged along the straight line in the relative displacement direction as Its integer multiple is set to four times here. Further, the concave portion 30 has a parallelogram shape arranged obliquely in a lattice shape. Therefore, the grid pitch PX of the plurality of recesses 30 arranged in a staggered manner is one-half of the arrangement pitch PU of the recesses 30 arranged on the straight line. Further, between the precursor machining region Q and the double-thread portion forming region U adjacent thereto, the phase of the deformation pitch PQ coincides with the phase of the arrangement pitch PU. In this manner, the thread blank material B smoothly rotates from the precursor machining region Q to the double-thread portion forming region U.

As described above, the double-threaded body D is characterized by having a total sectional area S1 of only the thread M of one of the 180-degree phase difference to the highest top MA of the thread M, M (refer to the eighth (B) diagram); The intersection MX of the highest top MA in the circumferential direction by 90 degrees differs only in the total sectional area S2 of the thread M (refer to the ninth (B) diagram).

Therefore, in the present embodiment, the portion of the double-threaded portion forming region U in the upstream-side precursor processing region Q is formed by changing the portion of the thread blank material B into the highest top portion MA of the thread M in advance. The portion which becomes the intersection MX of the thread M in the future is a short elliptical shape of the short axis, and the double-threaded portion forming region U can reduce the amount of plastic deformation of the thread blank material B. and, In the mold member 10, the precursor machining region Q and the double thread portion forming region U are integrally disposed in advance, and the deformation pitch PQ (the distance between the short axis and the long axis) of the precursor machining region Q and the double thread portion forming region U are made. The highest top of the thread has the same phase as the intersection (the quarter of the arrangement pitch PU). As a result, by performing a series of rolling operations, combining elliptical or oblong machining and thread processing, extremely precise double-threaded regions can be rolled with extremely high work efficiency.

As shown in FIG. 2A, the rigid surface 20 of the mold member 10 is provided with a single screw portion forming region J which is disposed adjacent to the double-threaded portion forming region U in the axial direction of the thread blank material B. In the single thread portion forming region J, a valley portion 50 extending in a strip shape to the hypothetical surface 22 is recessed, and the thread portion of the single thread region of the double-threaded body D of the eighth and ninth figures is rolled by the valley portion 50. The valley portion 50 only needs to be disposed by tilting the angled portion in the direction in which the thread blank material B is relatively displaced. When the thread blank material B is placed so as to traverse the double threaded portion forming region U and the single threaded portion forming region J, as shown in the eighth and ninth drawings, the region J can be formed by a single thread portion. A single threaded region is formed, and the double-threaded portion D of the double-threaded region is formed by the double-threaded portion forming region U.

As shown in the second C diagram, the die 10 can be divided into parts by the boundary between the double-threaded portion forming region U and the single threaded portion forming region J. The double threaded body D needs to change the length of a single threaded area according to specifications. When the die 10 is formed in advance and can be divided, the length of the single screw region of the double-threaded body D can be easily changed only when the component corresponding to the single screw portion forming region J is changed to have a different width in the axial direction. Further, since the double-threaded portion forming region U can be easily replaced as a component, the shape of the thread M of the double-threaded portion forming region U is changed, or the axis of the double-threaded portion forming region U and the single threaded portion forming region J is replaced. In the directional arrangement, the double-threaded portion forming region U or the like is disposed on both sides of the single screw portion forming region J, and various changes can be easily made. Generally, when the dimension of the double-threaded portion forming region U is maintained in the axial direction and the setting is increased, it is possible to correspond to the double-threaded region of all lengths.

The die 10 can be divided into three component pieces J1, J2, and J3 by a single thread portion forming an intermediate boundary in the axial direction of the region J. In this way, for example, a plurality of component pieces having a width of 5 mm in the axial direction are prepared in advance, and the axial width of the single screw portion forming region J can be arbitrarily adjusted in units of 5 mm in accordance with the number of pieces of the component pieces. This idea can also be applied to the double-threaded portion forming region U.

As shown in FIG. 2A, the rigid surface 20 of the die 10 has a planar cylinder (which may also be a circle) which is disposed adjacent to the single screw portion forming region J in the B-axis direction of the thread blank material. The column portion forms a region K. The cylindrical portion forming region K rolls the cylindrical region of the double-threaded body D of the eighth figure and the ninth figure. As shown in the second C diagram, the boundary between the cylindrical portion forming region K and the single screw portion forming region J can be divided. The double threaded body D needs to change the length of the cylindrical area according to its specifications. When the division is made in advance in such a manner that the parts corresponding to the cylindrical portion forming region K in the mold sheet 10 are changed to have different axial widths, the length of the cylindrical region of the double-threaded body D can be easily changed.

Further, the die sheet 10 may be further divided into a component piece at a midway boundary in the axial direction of the cylindrical portion forming region K. In this way, for example, a plurality of component pieces of the cylindrical portion forming region K having a width of 5 mm in the axial direction are prepared in advance, and the axial direction width of the cylindrical portion forming region K can be arbitrarily adjusted in units of 5 mm depending on the number of pieces of the component pieces, but here There is no special illustration.

The rolling method of the double-threaded body D using the rolling die structure of the present embodiment is a pressure-bonding of the cylindrical thread blank material B, and is relatively displaced in a direction orthogonal to the axial direction of the thread blank material B. Further, the surface of the thread blank material B is deformed to roll a double-threaded body D having a right-hand thread portion and a left-thread portion in the same region in the axial direction.

When rolling is performed using the plate-shaped mold member 10 of the present embodiment, as shown in the first (A) diagram, one of the flat-die members 10 is fixed, and the distance between the outermost surfaces is set to a predetermined interval d. One of the flat mold members 10 causes the other flat mold member 10 to be relatively displaced while maintaining the interval d. Of course, the flat mold parts 10 and 10 only need to be relatively displaced between the two flat mold parts 10 and 10, and the two sides can be configured to be displaced in different directions from each other, or the interval d is not constant, and Each of the flat mold members 10 is disposed obliquely.

As shown in FIG. 2A, the double-threaded portion adjustment method N of the present embodiment is such that the double-threaded portion adjustment region N is disposed on the downstream side in the relative displacement direction of the double-threaded portion forming region U. In the double-thread portion forming region U rolling, even if the thickness of the thread blank material B is reduced due to the thickness movement and the thickness increase is insufficient, the shaft portion E can be formed into a perfect circle in the double-thread portion adjustment region N where the thickness is easy to move. The top edge of the highest top MA of the thread M is sufficiently increased in thickness. As a result, the shape accuracy of the thread M can be remarkably improved by the correction action of the double thread portion adjustment region N.

In particular, in the present embodiment, since the double-threaded region is formed in the double-threaded portion forming region U for the thread blank material B, the screw thread M of the double-threaded region is naturally embedded in the first and second threaded portion adjustment regions N on the downstream side. The second adjustment is in the valley portions 61, 62. Therefore, the thread M It is itself a guide, and the phase of the first and second adjustment valleys 61, 62 is suppressed from deviating from the thread blank material B. Incidentally, when the phases of the first and second adjustment valley portions 61 and 62 are deviated from the thread blank material B, the position of the intersection portion MX of the thread M changes in the circumferential direction, and finally the thread shape of the vicinity of the intersection portion MX is caused. damage.

Further, in the present embodiment, as shown in the sixth (B) diagram, the concave portion 50 in the double-thread portion forming region U and the adjustment valley portions 61 and 62 in the double-thread portion adjusting region N are continuous at the boundary thereof. Therefore, the thread blank material B between the double-threaded portion forming region U and the double-threaded portion adjusting region N is smoothly rotated, and the concave portion 50 of the double-threaded portion forming region U and the adjusted valley portion of the double-threaded portion adjusting region N can be suppressed. The phase of 61, 62 offsets the thread blank material B from each other.

Further, the rolling method of the present embodiment is as shown in the second A diagram and the third (A) diagram, and is an arrangement pitch T1, T2, T3 of the direction in which the concave portions 30 in the double-threaded portion forming region U are relatively displaced. The smaller side from the upstream side toward the downstream side when it is displaced relative to the thread blank material B. That is, it becomes T1>T2>T3>. As shown in the third (B) diagram, when the thread blank material B is rotated from the upstream to the downstream in the double-thread portion forming region U, the shaft portion E from which the thread M is removed is gradually formed. The outer circumferential distance of the shaft portion E (assuming a perfect circle, the diameter × π) gradually decreases toward the downstream, and finally becomes a substantially perfect circular shape. Therefore, since the rotational distance traveled by the one-time rotation of the thread blank material B is also gradually decreased toward the downstream, the arrangement pitches T1, T2, T3 of the direction in which the concave portions 30 are relatively displaced are reduced in advance by this. At this time, the concave portion 30 can be crimped to the thread blank material B in rotation at substantially the same phase at any time, and the shape/size accuracy of the thread M can be remarkably improved.

As shown in the third (B) diagram, in the double-threaded portion forming region U, the distance L1, L2, L3, ... from the central axis E1 of the thread blank material B and the hypothetical surface 22 may be from the thread blank material. The upstream side of the B relative displacement becomes smaller toward the downstream side. At this time, it is only necessary to set the opposite surface 22 of the pair of flat mold members 10 to be non-parallel, and the distance between them is gradually reduced toward the direction in which the rotational direction of the thread blank material B is gradually reduced.

Further, as shown in the fourth figure, the rolling method of the double-threaded body may be the maximum dimension W1, W2, W3 in the direction in which the plurality of concave portions 30 are relatively displaced in the double-threaded portion forming region U. The order of arrangement of the upstream side toward the downstream side is set to be gradually smaller. That is to become W1>W2>W3>. The final shape of the thread M is similar to the recess 30 on the most downstream side of the double-threaded portion forming region U. In addition, Since the arrangement pitches T1, T2, T3, ... are larger than the most downstream side and have a margin in space on the upstream side, the maximum size W1, W2, W3, ... of the setting recess 30 can be increased. Since the maximum size W1, W2, W3, ... of the recess 30 can increase the plastic deformation amount of the thread blank material B, the concave portion 30 on the upstream side can be plastically deformed as early as possible, and approach the final thread as it enters the downstream side. The shape of the tooth M is rolled.

Further, as shown in the first (B) diagram, in the case of so-called rolling rolling in which two or more round mold members 12, 12 of a cylindrical shape or a cylindrical shape are used in combination, the two circular mold members 12, 12 are rotated with each other. The axes are parallel and the distance between the outermost surfaces is maintained at a specified interval d. Then, the interval d can be maintained and rotated separately. At this time, the respective round mold members 12, 12 may also rotate in opposite directions to each other, or may rotate in the same direction.

Even when the circular die member 12 is used, in the double-thread portion forming region U, the distances L1, L2, L3, ... of the central axis E1 of the thread blank material B from the hypothetical surface 22 can be relatively changed from the thread blank material B. The upstream side of the bit becomes smaller toward the downstream side. At this time, as shown in the fifth (A) diagram, the distances L1, L2, L3, ... from the central axis E1 of the at least one of the circular die members 12 to the hypothetical surface 22 are gradually increased as they progress in the circumferential direction. Change the way to change position. As a result, the opposite one gradually becomes smaller toward the direction in which the distance of the surface 22 is rotated toward the thread blank material B.

Further, as shown in the first (C) diagram, in the case of a so-called planetary type rolling in which one of the arc-shaped mold members 13 is used and the other is rolled using a cylindrical or cylindrical circular mold member 12, One of the arc-shaped mold members 13 is fixed, and the other circular mold member 12 is rotatably held so as to have a predetermined interval d with the distance between the outermost portions. Then, the interval d is maintained and the rigid surfaces 20, 20 are relatively displaceable.

Even when the circular-arc mold member 13 is used, in the double-thread portion forming region U, the distances L1, L2, L3 of the central axis E1 of the thread blank material B from the hypothetical surface 22 can be obtained from the thread blank material B. The upstream side of the relative displacement becomes smaller toward the downstream side. At this time, as shown in the fifth (B) diagram, the distances L1 and L2 between the hypothetical surface 22 on the inner circumferential side of the arc-shaped mold member 13 and the central axis E1 of the cylindrical circular-die member 12 on the opposite side are obtained. , L3..., is displaced in such a manner as to gradually become smaller as it travels in the circumferential direction. As a result, the direction of the rotation of the cylindrical circular die member 12 on the opposite side from the assumed surface 22 toward the thread blank material B gradually becomes smaller. Further, when the rolling method of the present embodiment is employed, as shown in FIG. 2A, the thread blank material B can be ovalized or formed by the front body processing region Q of the mold member 10. Long round processing.

More specifically, before the thread blank material B enters the double-thread portion forming region U, the thread blank material B is previously changed into a substantially elliptical shape.

At this time, in the front body machining region Q of the upstream side of the double-threaded portion forming region U, the thread blank material B is formed into a long axis which will become the highest top portion of the thread M, and will become the intersection of the thread M in the future. The part is a rough elliptical shape of the short axis. As a result, the double thread forming portion U can reduce the amount of plastic deformation of the thread blank material B. Further, in the mold member 10, the precursor machining region Q and the double-thread portion forming region U are integrally disposed in advance, and the deformation pitch PQ (the distance between the short axis and the long axis) of the precursor machining region Q and the double-thread portion forming region are formed. The highest top of the U thread has the same phase as the intersection (the quarter of the arrangement pitch PU), and the elliptical or oblong machining and the thread processing are combined by a series of rolling actions. Extremely precise double-threaded areas can be rolled with extremely high efficiency.

As shown in FIG. 2A, the rigid surface 20 of the mold member 10 is provided with a single screw portion forming region J which is disposed adjacent to the double-threaded portion forming region U in the axial direction of the thread blank material B. In the single thread portion forming region J, a valley portion 50 extending in a strip shape to the hypothetical surface 22 is recessed, and the thread portion of the single thread region of the double-threaded body D of the eighth and ninth figures is rolled by the valley portion 50. The valley portion 50 only needs to be disposed by tilting the angled portion in the direction in which the thread blank material B is relatively displaced. When the thread blank material B is placed so as to straddle both the double threaded portion forming region U and the single threaded portion forming region J, as shown in the eighth and ninth drawings, the region J can be formed by a single thread portion. A single threaded region is formed, and the double-threaded portion D of the double-threaded region is formed by the double-threaded portion forming region U.

Further, in the rolling method of the present embodiment, as shown in FIG. 2C, the die sheet 10 can be divided into parts by the boundary between the double-threaded portion forming region U and the single screw portion forming region J. When the die 10 is formed in advance and can be divided, the length of the single screw region of the double-threaded body D can be easily changed only when the component corresponding to the single screw portion forming region J is changed to have a different width in the axial direction.

Since the die 10 can be divided into three component pieces J1, J2, and J3 by a single thread portion forming the intermediate boundary of the region J in the axial direction, the single thread portion can be arbitrarily adjusted according to the number of the component pieces. The direction of the axis of the area J is wide. This idea can also be applied to the double-threaded portion forming region U.

The rolling method of the present embodiment is as shown in the second C diagram, and the cylindrical portion forming region K and the single The boundary of a thread forming portion J can be divided. The double threaded body D needs to change the length of the cylinder (also cylindrical) area according to its specifications. When the division is made in advance in such a manner that the parts corresponding to the cylindrical portion forming region K in the mold sheet 10 are changed to have different axial widths, the length of the cylindrical region of the double-threaded body D can be easily changed.

The modification of the above embodiment is, for example, a rolling die structure shown in the tenth (A). This rolling die structure is disposed on the rigid surface 20 of the mold member 10 on the downstream side of the precursor machining region Q, and the double-thread portion adjustment region N is disposed on the upstream side of the double-threaded portion forming region U. In this example, both the first adjustment portion N1 and the second adjustment portion N2 in the double-thread portion adjustment region N are disposed on the upstream side of the double-thread portion formation region U. In this manner, one single thread is rolled by the first adjustment valley portion 61 of the first adjustment portion N1, and the second adjustment valley portion 62 of the second adjustment portion N2 is rolled to overlap with the single thread. The thread, as a result, forms a prosthetic double-threaded region on the thread blank material B before entering the double-threaded portion forming region U.

In this manner, when the single adjustment thread N and the second adjustment portion N2 are used to roll each single thread without the unevenness or undulation on the circumferential surface of the thread blank material B, the thread of one single thread and the thread of the other single thread are used. Phase deviation. Therefore, the present modification is a method in which the thickness of the thread blank material B is easily moved in the double-threaded portion adjustment region N, and the thread of the double-threaded region is roughly formed (formation of the precursor double-threaded region) by The double threaded portion forming region U on the downstream side produces a precise thread of the double threaded region. That is, the double-threaded portion adjustment region N on the upstream side forms a rough double-threaded region in which the tolerance is allowed, and the error is corrected in the double-threaded portion adjustment region N on the upstream side.

Therefore, even in the rolling die structure of this modification, the shape accuracy of the thread M of the last double-threaded body D can be remarkably improved by forming the precursor thread by the double-threaded portion adjustment region N. At this time, the upstream side precursor processing region Q may be omitted.

Further, in the mold member 10, the second double screw portion adjustment region N may be disposed on the downstream side of the double screw portion forming region U. Further, as shown in the tenth (B) diagram, the first adjustment portion N1 may be disposed on the upstream side of the double-threaded portion forming region U, and the second adjustment portion N2 may be disposed downstream of the double-threaded portion forming region U. side.

In this manner, when the first adjustment portion N1 and the second adjustment portion N2 are used to roll each single thread without using irregularities or undulations on the circumferential surface of the thread blank material B, the thread of one single thread is The phase deviation of the thread of the other single thread. Therefore, the present modification is a method in which the thickness of the thread blank material B is easily moved in the double-threaded portion adjustment region N, and the thread of the double-threaded region is roughly formed (formation of the precursor double-threaded region) by The double threaded portion forming region U on the downstream side produces a precise thread of the double threaded region. That is, the double-threaded portion adjustment region N on the upstream side forms a rough double-threaded region in which the tolerance is allowed, and the error is corrected in the double-threaded portion adjustment region N on the upstream side.

In the tenth (B) diagram, the first adjustment portion N1 of the double-thread portion adjustment region N is disposed on the upstream side of the double-thread portion forming region U, and the second adjustment portion N2 of the double-thread portion adjustment region N is disposed in the double The threaded portion is formed on the downstream side of the region U, but the present invention is not limited thereto. For example, the first adjustment portion N1 and the second adjustment portion N2 may be disposed in the double-threaded portion adjustment region N on the upstream side, and the first adjustment portion N1 and the second adjustment portion N2 may be disposed on the downstream double-threaded portion adjustment region N. . In this way, it can be corrected more accurately.

The modification of the above embodiment is a rolling die structure shown in Fig. 11. The rolling die structure is disposed on the rigid surface 20 of the mold member 10, and the double-thread portion adjustment region N (the first adjustment portion N1 and the second adjustment portion N2) is disposed on the downstream side of the first double-thread portion forming region U1. The second double thread portion forming region U2 is disposed on the downstream side thereof. By adopting the rolling die structure, the double-threaded region is formed in the first double-threaded portion forming region U1, and the shape of the double-threaded region is corrected in the double-threaded portion adjusting region N, and then The shape of the double-threaded region is precisely corrected by the second double-threaded portion forming region U2. Therefore, the distance of the second double thread portion forming region U2 in the relative moving direction can be shorter than the distance of the first double thread portion forming region U1. Further, since the second double-threaded portion forming region U2 is intended to correct the double-threaded region, it can be conceptually regarded as a part of the double-threaded portion adjusting region N.

In addition, a modification of the above embodiment is, for example, a rolling die structure shown in the twelfth (A). This rolling die structure is formed in the rigid surface 20 of the mold member 10, and a partition region SP is disposed between the double screw portion forming region U and the single screw portion forming region J. The partitioning region SP has a role of forming a plurality of play in the boundary portion between the double-threaded portion forming region U and the single threaded portion forming region J by setting the amount of protrusion corresponding to the rolled double-threaded body D valley diameter. Thus, as shown in the twelfth (B) diagram, since the constricted portion V which becomes a small width of the valley diameter is formed between the double-threaded region of the double-threaded body D after the rolling and the single-threaded region, The distance between the double thread and the single thread When so, the transfer of the thread of the single threaded area and the double threaded area can be smoothly performed.

Here, the case where the partition region SP is disposed between the double-threaded portion forming region U and the single screw portion forming region J is exemplified, but it is also preferable that the body processing region Q is before the mold member 10 (refer to FIG. 2A). In this case, the partition region SP is disposed at a boundary corresponding to the double screw portion forming region U and the single screw portion forming region J. Thus, as shown in the twelfth (C) diagram, the neck portion V can be formed in the so-called precursor of the thread blank material B through the state of the precursor processing region Q (the precursor can also be defined as a portion of the thread blank material). . As a result, the boundary between the double-threaded portion forming region U and the single threaded portion forming region J is left without a partitioning region, and since the neck portion V is still present, the rolling is smooth. Further, in addition to the constricted portion V formed by the partition region SP of the mold member 10, the constricted portion V may be formed in advance in the thread blank material B itself supplied to the mold member 10.

In addition, the above-described embodiment is a case where the thread blank material B has the same cross-sectional area in both the double-thread portion forming region U and the single screw portion forming region J in the mold structure, but the present invention is not limited thereto. For example, as shown in the twelfth (C) diagram, it is preferable to compare with the sectional area of the double-thread corresponding area BU corresponding to the thread blank material B of the double-threaded portion forming region U, and the increase setting corresponds to the single thread portion forming region J. The single thread of the thread blank material B corresponds to the sectional area of the region BJ. It is understood from the double-threaded body D of the twelfth (B) figure that the double-threaded area and the single-threaded area have the same height, but the height of the thread of the double-threaded portion is locally small. That is, the volume of the unit thread of the double-threaded area in the double-threaded body D and the volume of the unit thread of the single-threaded area are larger in the single thread area. Therefore, it is preferable to set a volume difference in advance between the double thread corresponding region BU of the thread blank material B and the single thread corresponding region BJ by the volume difference corresponding to the thread of the double thread and the single thread.

Further, here, in addition to forming the necking V at the boundary between the double thread corresponding region BU of the thread blank material B and the single thread corresponding region BJ, it is preferable to form a tapered surface at the boundary. Thus, when the thread blank material B is formed by forging, it can be formed in advance.

Although the mold structure and the rolling method for rolling the double-threaded body D have been described above, it is needless to say that various modifications can be made without departing from the spirit and scope of the invention.

Claims (12)

A mold structure for a double-thread rolling method, comprising: a mold member having a rigid surface that is pressed against a thread blank material and relatively displaced; and the mold member includes a double-thread portion forming region that is coupled Forming a substantially parallelogram shape as viewed from a normal direction of the hypothetical surface obtained between the outermost surfaces of the surface, and arranging a plurality of recesses recessed from the hypothetical surface along the direction of the relative displacement; and a double-threaded portion adjustment region The upstream side and/or the downstream side in the direction of the relative displacement of the double-threaded portion forming region are inclined at an angle corresponding to the rising angle of the double-threaded portion forming region, and are disposed on the aforementioned assumed surface band extending. The valley is adjusted from the surface of the hypothesis. The double-thread portion rolling die structure according to the first aspect of the invention, wherein the double-threaded portion adjustment region includes: a first adjustment portion that is inclined at a degree corresponding to a rising angle of a single thread, and the arrangement corresponds to a first adjustment valley portion of the one single thread formed in the double thread portion forming region; and a second adjustment portion disposed on the downstream side of the first adjustment portion in the direction of the relative displacement The angle of the rising angle of the other single thread is inclined, and the second aforementioned adjustment valley corresponding to the other single thread formed in the double threaded portion forming region is disposed. The mold structure for double-thread rolling in the first or second aspect of the patent application, wherein the adjustment valley portion in the double-thread portion adjustment region is continuous with the concave portion in the double-thread portion forming region. The way to form. The mold structure for double-thread rolling in the first aspect of the invention, wherein the double-threaded portion forming region has a maximum dimension in a direction of the relative displacement of the plurality of recesses, and is arranged from the upstream side toward the downstream side. The part in which the order is smaller and set. The mold structure for double-thread rolling in the first aspect of the invention, wherein the double-threaded portion forming region has a distance between a central axis of the thread blank material and the assumed surface, and is relatively displaced from the thread blank material. The portion where the upstream side becomes smaller toward the downstream side and is set. The mold structure for double-thread rolling in the first aspect of the invention, wherein the mold member has a hypothetical surface obtained by joining the outermost surfaces of the surfaces, and gradually approaches the direction along the direction of the relative displacement a region of the axis of the thread blank material; and a precursor processing region having a region that gradually deviates from the axis. The mold structure for double-thread rolling in the sixth aspect of the invention, wherein at least a part of the precursor processing region in the mold member is in the upstream of the threaded blank material when the threaded blank material is relatively displaced. side. The mold structure for double-thread rolling in the first aspect of the invention, wherein the mold member includes a single thread portion forming region adjacent to the double-thread portion forming region in a state in which the axial direction of the thread blank material is deviated The arrangement is configured such that the direction of the relative displacement is inclined at an angle of elevation, and is disposed in a valley portion of the aforementioned assumed surface that extends in a strip shape and is recessed from the hypothetical surface. A mold structure for adjusting a double-threaded body, comprising: an adjustment mold member having a rigid surface that is pressed against a thread blank material forming a double-threaded region and relatively displaced; and the adjustment mold member has a double-thread portion An adjustment region which is inclined at an angle corresponding to an angle of the aforementioned double-threaded region of the threaded blank material, and a hypothetical surface obtained by joining the outermost portions of the surface, extending in a strip shape and recessed from the hypothetical surface Adjust the valley. The double-threaded body adjustment mold structure according to claim 9, wherein the double-threaded portion adjustment region is provided with: a first adjustment portion that is inclined by a degree corresponding to a single angle of a single thread, and is provided with a first one of the adjustment grooves corresponding to a single thread of the double-threaded region of the thread blank material; and a second adjustment a portion disposed on a downstream side of the direction in which the first adjustment portion is relatively displaced, and inclined at a degree corresponding to the angle of the other single thread, and configured to correspond to the other single unit formed by the double-threaded region The second aforementioned adjustment of the thread is with the valley. A double-thread rolling method, characterized in that, when a mold member having a rigid surface is relatively displaced with respect to a thread blank material, the mold member is provided with a double-thread portion forming region which is connected between the outermost surfaces of the surfaces And the normal direction of the assumed surface is observed to form a substantially parallelogram shape, and a plurality of concave portions recessed from the hypothetical surface are arranged along the direction of the relative displacement; and the double-threaded portion adjustment region is configured The upstream side and/or the downstream side in the direction of the relative displacement of the double-threaded portion forming region are inclined so as to correspond to the angle of the rising angle of the double-threaded portion forming region, and are disposed on the assumed surface band extending from the assumption The adjustment of the surface recess is performed by means of a valley portion, and the double-threaded body is rolled by pressing and relatively displacing the mold member against the thread blank material. A double thread adjusting method, wherein when the adjusting mold member having a rigid surface is relatively displaced with respect to the thread blank material forming the double-threaded region, the adjusting mold member has a double-thread portion adjusting region, which is Corresponding to the manner in which the degree of elevation of the double-threaded region of the thread blank material is inclined, and the adjustment of the valley portion is performed by assuming that the surface of the double-threaded region is connected between the outermost portions of the surface of the threaded surface and is recessed from the hypothetical surface. The double-threaded region is adjusted by crimping and relatively displacing the double-threaded region of the thread blank material with the adjusting mold member.