JP2007132398A - Threaded fastener, manufacturing method of male threaded fastener and rolled dies - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a threaded fastener capable of significantly improving maximum fastening torque and holding force which is unlikely to loosen, a manufacturing method of a male threaded fastener and rolled dies. <P>SOLUTION: In the threaded fastener, a follow side flank angle β of the male screw part 5 or a female screw part is set to be zero or a negative angle or a positive angle not larger than one third of a lead angle or a positive angle not larger than 4°. In the case of manufacturing the male threaded fastener 1 of the threaded fastener with the male screw part 5, a blank is provided between a plurality of rolled dies of which follow side flank angle of a thread forming groove is set to be zero or a negative angle or a positive angle not larger than one third of the lead angle or a positive angle not larger than 4°, the blank is rolled between the rolled dies and a thread 8 of the male screw part 5 is formed by rolling. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a threaded part having a male threaded part or a female threaded part, a method for producing a male threaded part having a male threaded part, and a rolling die thereof, and particularly suitable for fastening small screws, bolts, set screws, nuts, etc. The present invention relates to a part, a method for manufacturing a male screw part, and a rolling die.

Conventionally, in order to improve the maximum tightening torque and holding force in a fastening male screw component such as a small screw, for example, as shown in Patent Document 1, the follower flank angle is made smaller than the advancing flank angle. Those having an asymmetric thread shape have been proposed.
Japanese Utility Model Publication 4-109215

  However, the conventional male threaded part having an asymmetric thread shape still has a problem that the maximum tightening torque and holding force cannot be sufficiently increased.

  In addition, along with this, it is difficult to make loose, and a component force in the direction perpendicular to the axis of the tightening force (this component force will be described in detail later) acts radially outward on the counterpart material, and Since the size cannot be made sufficiently small, there is a problem that the counterpart material may be damaged (so-called boss cracking at the time of screw fastening is an example of such damage).

  The present invention has been made in view of such conventional circumstances, and an object of the present invention is to provide a screw part, a method of manufacturing a male screw part, and a rolling method capable of significantly improving the maximum tightening torque and holding force. The purpose is to provide dies.

  Another object of the present invention is to provide a threaded part, a male threaded part manufacturing method, and a rolling die that are not easily loosened.

  Still another object of the present invention is to produce a threaded part and a male threaded part that can reduce or completely eliminate the force acting radially outward on the mating member during fastening and prevent the mating material from being damaged. It is to provide a method and a rolling die.

  Still other objects of the present invention will become apparent from the following description.

  The threaded component according to the first aspect of the present invention is a threaded component having a male threaded portion or a female threaded portion, wherein the follower flank angle of the male threaded portion or the female threaded portion is set to zero or a negative angle.

  In the threaded component according to the first aspect of the present invention, the trailing flank angle of the male thread part or the female thread part is zero or a negative angle, so that the component force in the direction perpendicular to the axis of the tightening force is zero or radially inward. Since the axial component force can be increased, the maximum tightening torque and the holding force can be greatly improved as compared with the conventional one, and accordingly, the loosening can be made difficult to occur.

  In addition, since the force acting radially outward on the mating member at the time of fastening can be eliminated, the mating material can be prevented from being damaged. Along with this, the thickness of the counterpart material can also be reduced.

  The screw component according to the second aspect of the present invention is a screw component having a male screw portion or a female screw portion, wherein the follower flank angle of the male screw portion or the female screw portion is a positive angle and not more than 1/3 of the lead angle. It is.

  A screw component according to a third aspect of the present invention is a screw component having a male screw portion or a female screw portion, wherein the follower flank angle of the male screw portion or the female screw portion is a positive angle and 4 degrees or less. .

  In the case of a normal single thread, the follower flank angle should be 4 degrees or less, more preferably 1/3 or less of the lead angle. Further, when the lead angle becomes large like a multi-thread screw, the follower side flank angle may be larger than 4 degrees, but in that case, it should be 1/3 or less of the lead angle.

  In the screw parts according to the second and third aspects of the present invention, the follow-up flank angle of the male screw portion or the female screw portion is set to a positive angle and 1/3 or less or 4 degrees or less of the lead angle. Even if the component force in the perpendicular direction becomes radially outward, the size can be minimized and the axial component force can be increased. While being able to do, it can make it hard to produce looseness.

  Further, since the force acting radially outward on the mating member during fastening can be minimized, the mating material can be prevented from being damaged. Along with this, the thickness of the counterpart material can also be reduced.

  According to a first aspect of the present invention, there is provided a method for manufacturing a male screw part, wherein blanks are supplied between a plurality of rolling dies each having a follower flank angle of a thread forming groove set to zero or a negative angle, and the plurality of rolling By moving the dies relatively, the blank is rolled between the plurality of rolling dies, and the thread on the blank is formed by rolling in the thread forming groove, so that the follower side flank angle of the male thread portion is zero or A male screw part having a negative angle is manufactured.

  According to the method for manufacturing a male screw component according to the first aspect of the present invention, a male screw member having a male thread portion among the screw components according to the first aspect of the present invention can be manufactured.

  The manufacturing method of the external thread component according to the second aspect of the present invention supplies a blank between a plurality of rolling dies in which the follower flank angle of each thread forming groove is a positive angle and 1/3 or less of the lead angle. And moving the plurality of rolling dies relative to each other to roll the blank between the plurality of rolling dies and forming a thread on the blank by rolling in the thread forming groove. A male threaded part having a positive flank angle and a lead angle of 1/3 or less is manufactured.

  According to the method for manufacturing a male screw component according to the second aspect of the present invention, a male screw member having a male screw portion among the screw components according to the second aspect of the present invention can be manufactured.

  According to a third aspect of the present invention, there is provided a method of manufacturing a male threaded part, wherein blanks are supplied between a plurality of rolling dies in which the follower flank angle of each thread forming groove is a positive angle and 4 degrees or less. The rolling dies of the external thread portion are formed by rolling the blank between the plurality of rolling dies and forming a thread on the blank by rolling in the thread forming groove. Is a male screw part having a positive angle of 4 degrees or less.

  According to the method for manufacturing a male screw component according to the third aspect of the present invention, a male screw member having a male screw portion among the screw components according to the third aspect of the present invention can be manufactured.

A rolling die according to the first aspect of the present invention is a rolling die for producing a male screw part having a male screw part by forming a male screw part by screw rolling,
The follower side flank angle of the thread forming groove forming the thread of the male threaded portion is set to zero or a negative angle.

  According to the rolling die according to the first aspect of the present invention, a male thread member having a male thread portion among the threaded parts according to the first aspect of the present invention can be manufactured.

A rolling die according to the second aspect of the present invention is a rolling die for producing a male screw part having a male screw part by forming a male screw part by screw rolling,
The follower side flank angle of the thread forming groove forming the thread of the male thread portion is a positive angle and not more than 1/3 of the lead angle.

  According to the rolling die according to the second aspect of the present invention, a male thread member having a male thread portion among the threaded parts according to the second aspect of the present invention can be manufactured.

A rolling die according to a third aspect of the present invention is a rolling die for producing a male screw part having a male screw part by forming a male screw part by screw rolling,
The follower side flank angle of the thread forming groove forming the thread of the male thread portion is a positive angle and 4 degrees or less.

  According to the rolling die according to the third aspect of the present invention, a male screw member having a male thread portion among the screw parts according to the third aspect of the present invention can be manufactured.

According to the present invention,
(A) Maximum tightening torque and holding force can be greatly improved compared to the conventional method.
(B) It can be made difficult to loosen,
(C) During fastening, the opposing material can be prevented from being damaged by the force acting radially outward.
It is possible to obtain excellent effects such as.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  1-7 has shown the Example which applied this invention to the tapping screw which is one of the external thread components, its manufacturing method, and a rolling die. Among these, FIGS. 1-3 has shown the tapping screw 1 of the completed single thread | thread in a present Example. The tapping screw 1 includes a shaft portion 2 and a head portion 3 provided at one end portion of the shaft portion 2, and the head portion 3 is provided with a recess 4. A male screw portion 5 is provided on the outer periphery of the shaft portion 2. The advance side (tip side) flank angle α (see FIG. 3) of the male screw portion 5 is preferably 25 to 50 degrees (the advance side flank angle α in the figure is 40 degrees). On the other hand, the follower side (rear end side) flank angle β is generally zero as shown by the one-dot chain line 6a, as shown well in FIG. The flank surface 6 is concave as shown by the solid line.

  Next, the operation of the tapping screw 1 will be described in comparison with a conventional male screw. FIG. 18 shows a state in which the conventional male screw 31 is screwed into the mating member 7 (the lower side is the tip side of the male screw 31). As shown in this figure, a tightening force N perpendicular to the flank surface 32 acts on the follower flank surface 32 of the male screw 31. The tightening force N can be divided into an axial component force P parallel to the axis of the male screw 31 and an axial perpendicular component force F acting in a direction perpendicular to the axis of the male screw 31. Even if the male screw 31 has an asymmetric thread shape, the follower flank angle β is inclined in the direction opposite to the inclination of the leading flank angle α (forward direction), and is increased to at least 9 degrees at least. Therefore, the axially perpendicular component force F has a large value in the positive direction (radially outward).

  For this reason, as described above, there is a problem that the maximum tightening torque and the holding force cannot be sufficiently increased. In addition to this, there is a problem that it is difficult to cause loosening, and the counterpart material 7 may be damaged by the component force F in the direction perpendicular to the axis.

  However, in the tapping screw 1 of the present embodiment, the trailing flank angle β is totally zero degrees, so that it is well shown in FIG. 4 showing a state in which the tapping screw 1 is screwed into the mating member 7. Approximately, since the component force F in the direction perpendicular to the axis of the tightening force is zero, the tightening force N is equal to the component force P in the axial direction, and the component force P in the axial direction can be increased. In addition to this, loosening can be made difficult to occur.

  Moreover, since the force which acts on the other party material 7 to radial direction outward at the time of fastening can be eliminated, it can be prevented that the other party material 7 is damaged. Along with this, the thickness of the counterpart material can also be reduced.

  Furthermore, in the present embodiment, the follower flank surface 6 is concave (the longitudinal section is not linear but recessed), so that the contact area between the tapping screw 1 and the mating member 7 is increased. Therefore, the maximum tightening torque and the holding force can be further increased, and further loosening can be prevented.

  More specifically, in the present embodiment, since the follower flank surface 6 is concave as described above, even if the follower flank angle β is set to zero degree as a whole, on the outer peripheral side, , The follower side flank angle β becomes a negative angle, and when tightening, as schematically shown by a two-dot chain line 8a with respect to the upper thread 8 in FIG. The outer peripheral side is pushed toward the advancing side, and the thread 8 is deformed in a direction in which the outer diameter of the thread 8 is enlarged, and tends to bite into the mating member 7. Can be further increased, and further loosening can be prevented.

  However, in the present invention, the follower-side flank surface 6 may have a longitudinal section that is linear as indicated by the alternate long and short dash line 6a.

  Next, a method of manufacturing the tapping screw 1 of FIGS. 1 to 3 by thread rolling and a rolling flat die used at that time will be described with reference to FIGS. FIG. 5 shows a blank 1 ′ in the present embodiment, and this blank 1 ′ includes a head 3 and a shaft portion 2 ′ having a circular cross section.

  FIG. 6 shows a rolling process operation of the tapping screw 1 in this embodiment, and a blank 1 ′ is supplied between the fixed die 9 and the moving die 10 in exactly the same manner as in the case of normal screw rolling. The moving die 10 is moved in the linear direction as indicated by the arrow A, and the blank 1 ′ is rolled between the fixed die 9 and the moving die 10.

  FIG. 7 shows a cross-sectional view of the fixed die 9 (for reference, the tapping screw 1 in a rolled state is indicated by a one-dot chain line), and a screw having a shape corresponding to the thread 8 of the male screw portion 5 The mountain forming groove 11 is provided on the surface facing the blank 1 ′. Therefore, the follower flank angle of the thread forming groove 11 (an angle corresponding to the follower flank angle β of the completed tapping screw 1) is set to zero degrees. (The surface corresponding to the follower flank surface 6 of the completed tapping screw 1) is not a convex surface corresponding to the concave surface formed by the follower flank surface 6, but is a flat surface. The moving die 10 is also provided with a thread forming groove 13 similar to that of the fixed die 9. This moving die 10 also has a flat flank surface of the thread forming groove 13.

  In this manner, the fixed screw 9 and the moving die 10 are relatively moved as described above, and the blank 1 ′ is rolled between the two dies 9 and 10 so that the male screw portion as shown in FIGS. A tapping screw 1 having 5 can be manufactured. Here, in the present embodiment, the advancing flank angle of the thread forming grooves 11 and 13 of the dies 9 and 10 (an angle corresponding to the advancing flank angle α of the tapping screw 1 after completion) is sufficiently large, Since the follower side flank angle is set to zero degree, the thread 8 formed on the blank 1 'during rolling is advanced on the outer peripheral side by the dies 9, 10 in the axial direction from the side flank surface 14 side. While being pushed strongly, it is hardly pushed from the follower flank surface 12 side, so that the outer peripheral side of the follower flank surface 6 of the thread 8 is raised in the axial direction by the flow of the plastic blank 1 ′. On the other hand, since the radial intermediate portion of the follower-side flank surface 6 is depressed, the follower-side flank surface 6 of the completed tapping screw 1 can be made concave.

  8 to 10 show Embodiment 2 of the present invention. FIG. 8 is an enlarged cross-sectional view of the male thread portion 5 of the single thread tapping screw 1 in this embodiment, and also in this embodiment, the advancing-side flank angle α of the male thread portion 5 is 25 to 50 degrees. Preferred (advance flank angle α in the figure is 40 degrees). The follow-up flank angle β is generally a negative angle as indicated by the alternate long and short dash line 6a. More specifically, however, the follower flank surface 6 is a concave surface as shown by a solid line. The absolute value of the follower flank angle β is preferably 20 degrees or less, and particularly preferably 15 degrees or less (the absolute value of the follower flank angle β in the figure is 2 degrees).

  In the present embodiment, the follow-up flank angle β is generally a negative angle. Therefore, as shown in FIG. 9, the axially perpendicular component F is in the negative direction, that is, radially inward. be able to. Accordingly, since the force acting radially outward on the mating member 7 at the time of fastening can be eliminated, the mating material 7 can be prevented from being damaged. As a result, the thickness of the counterpart material 7 can be reduced.

  Further, by making the absolute value of the trailing flank angle β relatively small, the axial component force P can be increased, the maximum tightening torque and the holding force can be improved, and accordingly, loosening is less likely to occur. be able to.

  Further, since the follower side flank angle β is a negative angle as a whole, the outer periphery of the thread 8 is caused by the reaction force from the mating member 7 during tightening, as schematically shown by a two-dot chain line 8a in FIG. Since the thread 8 is deformed in the direction in which the outer side is pushed forward and the outer diameter of the thread 8 is enlarged, there is a tendency to try to bite into the mating member 7, so that the maximum tightening torque and holding force can be increased. While making it larger, it is possible to make it more difficult to loosen. In particular, in the present embodiment, since the follower flank surface 6 is concave, the absolute value of the negative angle of the follower flank angle on the outer peripheral side of the thread 8 is larger than the absolute value of the overall follower flank angle β. Since the value can be increased, this effect can be further enhanced.

  Further, in this embodiment, since the follower flank surface 6 is concave, the contact area between the tapping screw 1 and the mating member 7 can be increased, so that the maximum tightening torque and holding force can be further increased. While increasing the size, it is possible to further prevent loosening.

  However, also in the present invention, the longitudinal side section of the follower flank surface 6 may be a straight line as indicated by the alternate long and short dash line 6a.

  FIG. 10 shows a cross-sectional view of the fixed die 9 in this embodiment (for reference, the tapping screw 1 in a rolled state is indicated by a one-dot chain line), and corresponds to the thread 8 of the male screw portion 5. A thread forming groove 11 having a shape is provided on the surface facing the blank 1 '. Accordingly, the follower flank angle of the thread forming groove 11 is a negative angle, but the follower flank surface 12 of the thread forming groove 11 is formed by the follower flank surface 6 of the tapping screw 1 after completion. It is not a convex surface corresponding to the concave surface, but is a flat surface. The moving die 10 is also provided with a thread forming groove 13 similar to that of the fixed die 9. This moving die 10 also has a flat flank surface of the thread forming groove 13.

  Also in the present embodiment, as in the case of the first embodiment, the fixed die 9 and the moving die 10 are relatively moved, and the blank 1 ′ is rolled between the two dies 9 and 10 as shown in FIG. A tapping screw 1 having such a male screw portion 5 can be manufactured. Here, since the advance side flank angle of the thread forming grooves 11 and 13 of the dies 9 and 10 is sufficiently large, the follower side flank angle is set to a negative angle. Since the thread 8 that is formed in 1 ′ is advanced strongly on the outer peripheral side by the dies 9 and 10 and is strongly pushed in the axial direction from the side flank surface 14 side, it is hardly pushed from the follower side flank surface 12 side. Due to the flow of the plastic blank 1 ′, the outer peripheral side of the follower flank surface 6 of the screw thread 8 is raised in the axial direction, while the radial intermediate portion of the follower flank surface 6 is depressed. The follower flank surface 6 of the tapping screw 1 can be made concave.

  11 to 13 show a third embodiment of the present invention. FIG. 11 is an enlarged cross-sectional view of the male screw portion 5 of the single thread tapping screw 1 in this embodiment. In this embodiment also, the advancing flank angle α of the male screw portion 5 is preferably 25 to 50 degrees. (The leading flank angle α in the figure is 40 degrees). The follow-up flank angle β is generally a positive angle as indicated by a one-dot chain line 6a, and the magnitude of the angle is 4 degrees or less or 1/3 or less of the lead angle (FIG. In this case, the overall follower flank angle β is 2 degrees and the lead angle is 6 degrees 45 minutes). More specifically, however, the follower flank surface 6 is a concave surface as shown by the solid line, as in the case of the above embodiments.

  In the case of a normal single thread, the follower flank angle should be 4 degrees or less, more preferably 1/3 or less of the lead angle. Further, when the lead angle becomes large like a multi-thread screw, the follower flank angle may be larger than 4 degrees, but in that case, it should be 1/3 or less of the lead angle.

  In the present embodiment, since the follower flank angle β is a positive angle, as shown in FIG. 12, the follower flank surface 6 has a vertical cross section that is linear as shown by a one-dot chain line 6a. If this is considered, the axially perpendicular component force F is directed radially outward. However, since the follower side flank angle β is 4 degrees or less or 1/3 or less of the lead angle, the component force F in the direction perpendicular to the axis is made sufficiently small so that the counterpart material 7 is not damaged. it can. As a result, the thickness of the counterpart material 7 can be reduced.

  First, since the value of the follower flank angle β is very small, the axial component force P can be increased, the maximum tightening torque and the holding force can be improved, and accordingly, loosening is less likely to occur. it can.

  Further, in the present embodiment as well, since the follower flank surface 6 is concave, even if the follower flank angle β is generally a small positive angle, the follower flank angle β is formed on the outer peripheral side. Becomes a negative angle, and when tightening, as schematically shown by a two-dot chain line 8 a in FIG. 12, the outer peripheral side of the thread 8 is pushed to the advancing side by the reaction force from the counterpart material 7, and the thread 8 Since the thread 8 is deformed in the direction in which the outer diameter is enlarged and tends to bite into the mating member 7, the maximum tightening torque and holding force are further increased, and further loosening is less likely to occur. be able to.

  Further, in this embodiment, since the follower flank surface 6 is concave, the contact area between the tapping screw 1 and the mating member 7 can be increased, so that the maximum tightening torque and holding force can be further increased. While increasing the size, it is possible to further prevent loosening.

  However, also in the present invention, the longitudinal side section of the follower flank surface 6 may be a straight line as indicated by the alternate long and short dash line 6a.

  FIG. 13 shows a cross-sectional view of the fixing die 9 in this embodiment (for reference, the tapping screw 1 in a rolled state is indicated by a one-dot chain line) and corresponds to the thread 8 of the male screw portion 5. A thread-forming groove 11 having a shape is provided on the surface facing the blank. Accordingly, the follower flank angle of the thread forming groove 11 is a positive angle and not more than 1/3 of the lead angle. The follower flank surface 12 of the thread forming groove 11 is formed by a tapping screw after completion. It is not a convex surface corresponding to the concave surface formed by one follower-side flank surface 6 but a flat surface. The moving die 10 is also provided with a thread forming groove 13 similar to that of the fixed die 9. This moving die 10 also has a flat flank surface of the thread forming groove 13.

  Also in the present embodiment, as in the case of the first and second embodiments, the fixed die 9 and the moving die 10 are relatively moved, and the blank 1 ′ is rolled between the two dies 9 and 10, so that FIG. A tapping screw 1 having a male threaded portion 5 as shown can be manufactured. Here, the flank angle of the advancing flank surface of the thread forming groove 11 of the dies 9 and 10 is made sufficiently large, while the follower flank angle is positive but very small, The formed thread 8 is advanced by the dies 9 and 10 on the outer peripheral side and is strongly pushed in the axial direction from the side flank surface 14 side, but is hardly pushed from the follower side flank surface 12 side. Since the outer peripheral side of the follower flank surface 6 of the screw thread 8 is raised in the axial direction due to the flow of the flesh of the blank 1 ′, the radial intermediate portion of the follower flank surface 6 is depressed. The follower flank surface 6 can be concave.

  14 and 15 show Example 4 of the present invention. This embodiment shows an embodiment in which the present invention is applied to a female screw component having a female screw portion, particularly a nut. A female screw portion 17 is provided on the inner periphery of the nut 16. The advance side flank angle α (see FIG. 15) of the female screw portion 17 is preferably 25 to 50 degrees (the advance side flank angle α in the figure is 40 degrees). On the other hand, the follower-side flank angle β is set to zero. The follower-side flank surface 18 is configured to have a straight longitudinal section (however, the follower-side flank surface 18 may be a convex surface).

  Such a nut 16 can be manufactured, for example, by rolling or cutting a material with a tap having a shape corresponding to the female screw portion 17.

  In the present embodiment, the male screw portion of the male screw component screwed into the nut 16 has a shape corresponding to the female screw portion 17 (however, the follower flank is similar to the male screw portion 5 of the tapping screw 1 in the first embodiment. By making the surface concave), the same effect as in the first embodiment can be obtained.

  FIG. 16 shows a fifth embodiment of the present invention. This embodiment also shows an embodiment in which the present invention is applied to a nut. The advance side flank angle α of the female thread portion 17 of the nut 16 is preferably set to 25 to 50 degrees (the advance side flank angle α in the figure is set to 40 degrees). On the other hand, the follower flank angle β is a negative angle. The absolute value of the follower flank angle β is preferably 20 degrees or less, and particularly preferably 15 degrees or less (the absolute value of the follower flank angle β in the figure is 2 degrees). The follower-side flank surface 18 is configured to have a straight longitudinal section (however, the follower-side flank surface 18 may be a convex surface).

  Such a nut 16 can also be manufactured, for example, by rolling or cutting a material with a tap having a shape corresponding to the female screw portion 17.

  Also in this embodiment, the male screw portion of the male screw part screwed into the nut 16 has a shape corresponding to the female screw portion 17 (however, the follower side flank is similar to the male screw portion 5 of the tapping screw 1 in the second embodiment. By making the surface concave), the same effect as in the second embodiment can be obtained.

  FIG. 17 shows Embodiment 6 of the present invention. This embodiment also shows an embodiment in which the present invention is applied to a nut. The advance side flank angle α of the female thread portion 17 of the nut 16 is preferably set to 25 to 50 degrees (the advance side flank angle α in the figure is set to 40 degrees). On the other hand, the follower flank angle β is a positive angle, but the magnitude of the angle is 4 degrees or less or 1/3 or less of the lead angle (the overall follower flank angle β in the figure is 2 degrees, the lead angle is 6 degrees 45 minutes). The follower-side flank surface 18 is configured to have a straight longitudinal section (however, the follower-side flank surface 18 may be a convex surface).

  Such a nut 16 can also be manufactured, for example, by rolling or cutting a material with a tap having a shape corresponding to the female screw portion 17.

Also in the present embodiment, the male thread portion of the male thread component screwed into the nut 16 has a shape corresponding to the female thread portion 17 (however, the trailing flank surface is a concave surface as in the case of the tapping screw 1 in the third embodiment. In other words, the same effects as those of the third embodiment can be obtained.

In the first to third embodiments, the male screw component is a tapping screw for processing a female screw on the mating member itself. However, the present invention is not limited to the tapping screw, but also a female screw provided in advance on the mating member. The present invention can also be applied to male screw parts to be combined, a manufacturing method thereof, and a rolling die.

  Moreover, in the said Examples 1-3, although the other party material 7 is made into the thick material, this invention is applicable also when the other party material is a thin plate. Further, the material of the counterpart material can be used for a wide variety of materials such as various metals and plastics.

  Further, the present invention can be applied not only to fastening screw parts such as small screws, bolts, set screws, and nuts but also to fastening male screw parts such as male screws used for hose bands.

  Further, the present invention is not limited to a general male screw part in which the cross section of the shaft portion is substantially circular, but the cross section of the shaft portion is a non-circular shape such as a polygonal shape such as a substantially triangular or pentagonal shape, or an elliptical shape. It can also be applied to male screw parts.

  As described above, the present invention is useful as a screw part for fastening and fastening, a method for producing a male screw part, and a rolling die.

It is a front view which shows the tapping screw (male thread component) in Example 1 of this invention. It is a longitudinal cross-sectional view which shows the said tapping screw. FIG. 6 is an enlarged cross-sectional view showing the thread of the tapping screw (the lower side is the tip side of the tapping screw). FIG. 3 is an enlarged cross-sectional view showing a state in which the tapping screw is screwed into a mating member (the lower side is the tip side of the tapping screw). In the said Example, it is a front view which shows the blank used as the raw material of a tapping screw. It is a top view which shows the rolling process operation | work of the tapping screw in the said Example 1. FIG. It is an expanded sectional view which shows the rolling die in the said Example 1. It is an expanded sectional view which shows the screw thread of the tapping screw in Example 2 of this invention (below is the front end side of a tapping screw). It is an expanded sectional view which shows the state by which the tapping screw of the said Example 2 was screwed in the other party material (below is the front end side of a tapping screw). It is an expanded sectional view which shows the rolling die in the said Example 2. It is an expanded sectional view which shows the screw thread of the tapping screw in Example 3 of this invention (below is the front end side of a tapping screw). It is an expanded sectional view which shows the state in which the tapping screw of the said Example 3 was screwed in the other party material (lower part is the front end side of a tapping screw). It is an expanded sectional view which shows the rolling die in the said Example 3. It is a longitudinal cross-sectional view which shows the nut in Example 4 of this invention. It is an expanded sectional view which shows the screw thread of the nut in the said Example 4. It is an expanded sectional view showing the screw thread of the nut in Example 5 of the present invention. It is an expanded sectional view showing the screw thread of the nut in Example 6 of the present invention. It is a longitudinal cross-sectional view which shows the state which screwed the conventional male screw into the other party material.

Explanation of symbols

1 Tapping screw (Male thread part)
1 'blank 5 male thread 6 follower flank face of tapping screw 7 mating material 8 thread of tapping screw 9 fixed die 10 moving die 11 thread forming groove of fixed die 12 follower flank surface of fixed die 13 screw of moving die Crest forming groove 14 Leading flank surface of fixed die 16 Nut 17 Female thread portion 18 Nut trailing flank surface 23, 24 Engagement piece α Tapping screw leading flank angle β Tapping screw trailing flank angle

Claims (11)

  A screw part having a male screw part or a female screw part, wherein the follower flank angle of the male screw part or the female screw part is zero or a negative angle.   A threaded part having a male threaded part or a female threaded part, wherein the follower flank angle of the male threaded part or the female threaded part is a positive angle and not more than 1/3 of the lead angle.   A screw component having a male screw portion or a female screw portion, wherein the follower flank angle of the male screw portion or the female screw portion is a positive angle and 4 degrees or less.   The screw component according to any one of claims 1 to 3, wherein the screw component has a male screw portion, and the follower flank surface of the male screw portion is a concave surface.   A blank is supplied between a plurality of rolling dies each having a flank flank angle of the thread forming groove of zero or a negative angle, and the plurality of rolling dies are moved relative to each other to move the blank to the plurality of rolling dies. A male threaded part that produces a male threaded part in which the follower flank angle of the male threaded part is zero or negative by rolling between rolling dies and forming a thread on the blank by rolling in the thread forming groove. Manufacturing method.   A blank is supplied between a plurality of rolling dies each having a positive flank angle of the thread forming groove and set to 1/3 or less of the lead angle, and the plurality of rolling dies are relatively moved. The blank is rolled between the plurality of rolling dies, and a thread is formed on the blank by rolling in the thread forming groove, so that the follower side flank angle of the male thread portion is a positive angle and a lead angle. A manufacturing method of a male screw part for manufacturing a male screw part of 1/3 or less.   A blank is supplied between a plurality of rolling dies in which the follower flank angle of each thread forming groove is a positive angle and 4 degrees or less, and the plurality of rolling dies are relatively moved to move the blank. A male screw in which the follower flank angle of the male screw portion is a positive angle and 4 degrees or less by rolling between the plurality of rolling dies and forming a screw thread on the blank by rolling in the thread forming groove. A method of manufacturing a male screw part for manufacturing a part. The follower flank surface of the thread forming groove of the rolling die is a flat surface, and the advance side flank angle of the thread forming groove is sufficiently large,
The outer peripheral side of the thread flank formed on the blank is strongly pressed in the axial direction from the advancing flank surface side by the rolling die, and the outer peripheral side of the follower flank surface of the screw thread formed on the blank is axial. In the meantime, the radial intermediate portion of the follower flank surface is recessed along with this, so that the follower flank surface of the male screw part of the male screw part after completion is formed as a concave surface. Item 8. A method for manufacturing a male screw part according to any one of Items 5 to 7. A rolling die for producing a male screw part having a male screw part by forming a male screw part by thread rolling,
A rolling die in which a follower flank angle of a thread forming groove forming a thread of the male thread portion is set to zero or a negative angle. A rolling die for producing a male screw part having a male screw part by forming a male screw part by thread rolling,
A rolling die in which a follower side flank angle of a thread forming groove forming a thread of the male thread portion is a positive angle and not more than 1/3 of a lead angle. A rolling die for producing a male screw part having a male screw part by forming a male screw part by thread rolling,
A rolling die in which a follower flank angle of a thread forming groove forming a thread of the male thread portion is a positive angle and 4 degrees or less.

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