JPH08232973A - Screw part molding method of metal plate made yoke and mold for screw part molding of metal plate made yoke - Google Patents

Abstract

PURPOSE: To lengthen length of a prepared hole for a screw in the axial direction as long as possible and to improve strength of a screw part by way of machining and hardening the periphery of the prepared hole by molding a burring part or an embossing part on a tightening part by press working and molding the prepared hole for the screw on this burring part or the embossing part. CONSTITUTION: A work 20 made of a metal plate having a previously molded shaft bar insertion part 11 and forked tightening parts 12, 13 is stored and sandwiched between a pair of holders 30, 31, a punch die 40 is stored between the forked tightening parts 12, 13 free to slide, and a hole for bolt insertion is punched on the tightening part 12 by a punch 50 from the side of the holder 30. Thereafter, the work 20 is sandwiched between a burring die 41 and the holder 30, a burring punch 51 is passed through from the side of the holder 30 by pressing the other tightening part 13 through the hole 15 for bolt insertion, the work 20 is pushed out into the inside of a cavity 41a formed on the burring die 41 and a prepared hole 20c for a screw is molded with a burring part 20b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threaded portion of a yoke made of a metal plate, which is provided with a cylindrical shaft rod insertion portion and a bifurcated fastening portion projectingly formed on one side of the shaft rod insertion portion. The present invention relates to a molding method and a metal mold for molding a screw portion of a metal plate yoke.

[0002]

2. Description of the Related Art FIG. 10 is a perspective explanatory view showing an example of a conventional metal plate yoke, and FIG. 11 is a sectional view taken along the line XI-XI of FIG.

The yoke 1 made of a metal plate has a cylindrical shaft rod insertion portion 2, bifurcated fastening portions 3 and 4 projecting from one side of the shaft rod insertion portion 2, and the fastening portions. The fork portion 5 is formed so as to project in the axial direction at right angles to 3 and 4.

One tightening portion 3 is provided with a bolt insertion hole 3a by machining such as a drill, and the other tightening portion 4 is also machined by a drill or the like for inserting a bolt. A through hole 4a is provided so as to coincide with the axis of the hole 3a, and a nut 6 having a screw portion 6a is welded so as to coincide with the axis of the through hole 4a.

Then, the bolt 7 is screwed into the threaded portion 6a of the nut 6 through the bolt insertion hole 3a, whereby the shaft rod 8 inserted in the shaft rod insertion portion 2 is tightened and fixed. .

[0006]

However, in the method of manufacturing the threaded portion 6a of the metal plate yoke 1 described above, since the bolt insertion hole 3a and the through hole 4a are machined by a drill or the like, burrs are formed. There is a problem that a manufacturing process becomes expensive because a process such as a picking process is required.

Further, the welding of the nut 6 causes a thermal strain to deform the periphery of the tightening portion 4 or spatter adheres to the screw portion 6a, which deteriorates the quality of the metal plate yoke 1. there were.

[0008] The present invention has been made to solve the above-mentioned problems of the prior art.
(EN) Provided are a method for forming a threaded portion of a metal plate yoke and a die for forming a threaded portion of the metal plate yoke, which allows a screw pilot hole as long as possible along the axial direction to be formed by press working. .

[0009]

In order to achieve the above object, in the method for forming a threaded portion of a yoke made of a metal plate according to a first aspect of the present invention, a shaft rod insertion portion which is formed in advance and one side thereof is projected. A work made of a metal plate having a formed bifurcated fastening portion is housed and sandwiched between a pair of holders, and a punching die is slidably housed between the bifurcated fastening portions. A first step of punching a bolt insertion hole in the one tightening portion from the one holder side with a punching punch, and punching out punched waste stored in a punched waste storage portion of the punching die by this first step. The second step of sliding and discharging the die, and the work from which the punched scraps have been discharged by the second step are housed and held between the burring die and the holder, and the burring punch is inserted from the holder side to the bolt insertion hole. Through A third step of pressing and penetrating the other tightening portion, pushing out a work into a cavity formed in the burring die to form a screw pilot hole together with the burring portion, and the burring portion obtained in the third step. And a fourth step of forming a threaded portion in the screw pilot hole.

According to the second aspect of the present invention, there is provided a die for forming a screw portion of a metal plate yoke, wherein the punching die has a flat plate shape, and the thickness of the die is thicker than that of the work. It is characterized in that it is formed by penetrating a punched-dust storage portion that is larger than the diameter of the hole.

According to another aspect of the present invention, in the metal plate yoke screw portion forming die, the burring die forms a concave cavity for forming the burring portion on the workpiece mounting side in cooperation with the burring punch. At the same time, a through hole for inserting a burring punch is formed continuously in this cavity.

Further, in the method of forming a threaded portion of a metal plate yoke according to a fourth aspect, a metal plate having a shaft rod insertion portion formed in advance and a bifurcated tightening portion protrudingly formed on one side thereof is used. The work piece is housed and held between a pair of holders, and a punching die is slidably housed between the fork-shaped tightening portions, and the one holder is clamped by the punching punch from the one holder side. A first step of punching a hole for inserting a bolt in a portion, a second step of discharging the punched dust stored in the punched-dust storage portion of the punching die by sliding the punching die, and the second step. The work from which the punched scraps have been discharged in the two steps is housed and sandwiched between the embossing die and the holder, and the embossing punch is pressed from the holder side to the other tightening portion through the bolt insertion hole to the embossing die. Formed ky A third step of extruding the work into the tee to form the embossed portion, and the work obtained in the third step is housed and held between a piercing die and a holder, and a pierce punch is inserted from the holder side to the bolt insertion hole. A fourth step of pressing and penetrating the embossed portion via the through hole to form a screw pilot hole in the embossed portion, and a fifth step of forming the screw portion in the screw pilot hole of the embossed portion obtained in the fourth step. It is characterized by consisting of a process.

Further, in the metal plate yoke screw portion forming die according to the present invention, the embossing die forms a concave cavity for forming the embossing portion on the mounting side of the work by the cooperation with the embossing punch. It is characterized by having done.

Further, in the metal mold for forming a threaded portion of a yoke of a metal plate according to a sixth aspect, the piercing die forms the same cavity as the cavity of the embossing die on the work mounting side and is continuous with this cavity. The feature is that a through hole for inserting a piercing punch is formed.

[0015]

According to the present invention, since the bolt insertion hole and the screw pilot hole are formed in the shaft rod insertion portion which has been formed in advance in the work, axial misalignment of both holes can be prevented and the quality can be improved. it can. Also, the burring part or embossed part is formed in the tightening part by press working, and the screw pilot hole is molded in this burring part or embossed part.Therefore, the axial length of the screw pilot hole should be minimized. It can be made longer, and work hardening occurs around the screw pilot hole. by this,
The strength of the screw part formed in the screw pilot hole can be improved.

Further, since it is formed by press working, the cost can be reduced significantly compared to the machining cost. Furthermore, since the welding process of the nut can be eliminated, it is possible to eliminate deformation due to thermal strain and improve the quality.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on the embodiments shown in the drawings.

1 to 4 relate to a first embodiment of the present invention, FIG. 1 is an explanatory view showing a forming process of a screw portion of a metal plate yoke, FIG. 2 is an explanatory sectional view of a burring die, and FIG. FIG. 4 is a sectional explanatory view of a burring punch, and FIG. 4 is a perspective explanatory view of a metal plate yoke.

As shown in FIG. 4, the metal plate yoke 10 is used.
Is a cylindrical shaft rod insertion portion 11, bifurcated fastening portions 12 and 13 projectingly formed on one side thereof, and the fastening portions 12 and 1.
Fork portion 14 formed to project in the axial direction orthogonal to 3
It consists of A bolt insertion hole 15 is provided in one tightening portion 12, and a screw portion 16 is provided in the other tightening portion 13.

As shown in FIG. 1 (a), the method of forming the threaded portion 16 of the metal plate yoke 10 according to the first embodiment includes a preformed rod insertion portion 11 and a bifurcated tightening portion. 1
The work 20 made of a metal plate having Nos. 2 and 13 is housed and sandwiched between the pair of holders 30 and 31, and the punching die 40 is slidably housed between the two-forked tightening portions 12 and 13. The first step of punching the bolt insertion hole 15 into the one tightening portion 12 from the one holder 30 side by the punching punch 50 and the punching of the punching die 40 by the first step as shown in FIG. 1B. A second step in which the punching waste 20a stored in the waste storing portion 40a is discharged by sliding the punching die 40, and as shown in FIG. 1C, the work 20 in which the punching waste 20a is discharged in the second step. Is housed and sandwiched between the burring die 41 and the holder 30, and the burring punch 51 is pressed from the holder 30 side through the bolt insertion hole 15 and penetrates through the burring punch 51 to form the burring die 41. Work 2 the cavity 41a
0 is pushed out, and the burring portion 20b and the screw pilot hole 2
As shown in FIG. 1D, the third step of molding 0c
The screw pilot hole 2 of the burring portion 20b obtained in the third step
0c and the 4th process of forming the screw part 16.

Further, details of the first embodiment will be described.

A punching die 40 as a metal mold for forming the screw portion 16 of the metal plate work 10 is flat and has a plate thickness thicker than that of the work 20, and a bolt insertion hole 15 is formed at an intermediate portion thereof. A punched residue storage portion 40a having a diameter larger than the diameter is formed.

Further, as shown in FIG. 2, a burring die 41 as a metal mold for molding the screw portion 16 of the metal plate yoke 10 has a concave cavity 41a formed on the work 20 mounting side. The burring portion 2 is attached to the work 20 by the cooperative action of the burring punch 41 and the burring punch 51.
0b can be molded. Also, the cavity 41a
Through hole 41b for inserting the burring punch 51 continuously
Is formed, and the punched scrap 2 is cut through the through hole 41b.
It is designed to discharge 0a.

Further, as shown in FIG. 3, the burring punch 51 as a screw portion forming punch of the metal plate yoke 10 has a large diameter portion 51 having the same diameter as the diameter of the bolt insertion hole 15.
a and a small diameter portion 51b having the same diameter as the diameter of the screw pilot hole 20c.

5 to 9 relate to a second embodiment of the present invention, FIG. 5 is an explanatory view showing a forming process of a thread portion of a yoke made of a metal plate, FIG. 6 is a sectional explanatory view of an embossing die, and FIG. Is a cross-sectional explanatory view of the piercing die, FIG. 8 is a cross-sectional explanatory view of the embossing punch, and FIG. 9 is a cross-sectional explanatory view of the piercing punch.

The method of forming the threaded portion 16 of the metal plate yoke 10 according to the second embodiment is the first step shown in FIG.
(The same as the first step of the first embodiment shown in (a)) and FIG.
The second step shown in FIG. 5B (the same as the second step of the first embodiment shown in FIG. 1B) and the workpiece from which the punched waste 20a has been discharged by the second step as shown in FIG. 5C. 20 is housed and sandwiched between the embossing die 42 and the holder 30, and the embossing punch 52 is inserted into the bolt insertion hole 15 from the holder 30 side.
The other tightening portion 13 is pressed through the embossing die 42
A third step of forming the embossed portion 20d by extruding the work 20 into the cavity 42a formed in FIG.
As shown in (d), the work 20 obtained in the third step is housed and held between the piercing die 43 and the holder 30, and the piercing punch 53 is inserted from the holder 30 side through the bolt insertion hole 15 to the embossed portion 20d. And a through step to form a screw pilot hole 20c in the embossed portion 20d, and as shown in FIG. 5E, the screw pilot hole 20c of the embossed portion 20d obtained in the fourth step. And a fifth step of forming the threaded portion 16 on.

Further, details of the second embodiment will be described.

As shown in FIG. 6, an embossing die 42 as a metal mold for forming the screw portion 16 of the metal plate yoke 10 has a concave cavity 42a formed on the work 20 mounting side. The embossed portion 20d can be formed on the work 20 by the cooperation with the embossing punch 52.

As shown in FIG. 7, the pierce die 43 as a metal mold for molding the screw portion 16 of the metal plate yoke 10 has the same cavity 43a as the cavity 42a of the embossing die 42 on the work 20 mounting side. At the same time, a through hole 43b for inserting the pierce punch 53 is formed continuously with the cavity 43a. And this through hole 4
The punching waste 20a is discharged from 3b.

Further, as shown in FIG. 8, the embossing punch 52 as a punch for forming the screw portion 16 of the metal plate yoke 10 has a large diameter portion 52 having the same diameter as the diameter of the bolt inserting hole 15.
a and a small diameter portion 52b having the same diameter as the diameter of the screw pilot hole 20c.

Further, as shown in FIG. 9, the pierce punch 53 as a metal mold for forming the threaded portion 16 of the metal plate yoke 10 has a large diameter portion 53a having the same diameter as the diameter of the bolt insertion hole 15.
And a small diameter portion 53b having the same diameter as the diameter of the screw pilot hole 20c.

According to the above-mentioned first or second embodiment,
Since the bolt insertion hole and the screw pilot hole are formed in the shaft rod insertion portion that is formed in advance on the work, the shaft center misalignment of both holes can be prevented and the quality can be improved. Further, since the burring portion 20b or the embossed portion 20d is formed in the tightening portion 13 by press working and the screw pilot hole 20c is formed in the burring portion 20b or the embossed portion 20d, the axial length of the screw pilot hole 20c is increased. The length can be made as long as possible, and the periphery of the screw pilot hole 20c is work hardened. As a result, the strength of the screw portion 16 formed in the screw pilot hole 20c can be improved.

Further, since it is formed by press working, the cost can be reduced significantly compared to the machining cost. Further, since the welding process of the nut 6 can be omitted, the deformation due to thermal strain can be eliminated and the quality can be improved.

[0034]

As described above, according to the present invention, since the bolt insertion hole and the screw pilot hole are formed in the shaft rod insertion portion formed in advance on the work, the misalignment of the shafts of both holes can be prevented. The quality can be improved. Also, the burring part or embossed part is formed in the tightening part by press working, and the screw pilot hole is molded in this burring part or embossed part.Therefore, the axial length of the screw pilot hole should be minimized. It can be made longer, and work hardening occurs around the screw pilot hole. As a result, the strength of the screw portion formed in the screw pilot hole can be improved.

Further, since it is formed by press working, the cost can be reduced significantly compared to the machining cost. Furthermore, since the welding process of the nut can be eliminated, it is possible to eliminate deformation due to thermal strain and improve the quality.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a process of forming a screw portion of a metal plate yoke according to a first embodiment of the present invention.

FIG. 2 is a sectional explanatory view of the burring die.

FIG. 3 is a cross sectional explanatory view of a burring punch.

FIG. 4 is a perspective explanatory view of the same metal plate yoke.

FIG. 5 is an explanatory view showing a step of forming a threaded portion of the metal plate yoke according to the second embodiment of the present invention.

FIG. 6 is a cross-sectional explanatory view of an embossing die of the same.

FIG. 7 is a sectional view of the piercing die.

FIG. 8 is a cross-sectional explanatory view of an embossing punch of the same.

FIG. 9 is a sectional explanatory view of a piercing punch.

FIG. 10 is an explanatory perspective view showing an example of a conventional metal plate yoke.

11 is a cross-sectional view taken along the line XI-XI of FIG.

[Explanation of Codes] 10 Yoke made of metal plate 11 Shaft rod insertion part 12 Tightening part 13 Tightening part 15 Bolt insertion hole 16 Screw part 20 Work piece 20a Punching scrap 20b Burring part 20c Screw pilot hole 20d Embossing part 30 Holder 31 Holder 40 Punching Die 40a Punching Dust Storage 41 Burring Die 41a Cavity 41b Through Hole 42 Embossing Die 42a Cavity 43 Piercing Die 43a Cavity 43b Through Hole 50 Punching Punch 51 Burring Punch 51a Large Diameter 51b Small Diameter 52 Embossing Punch 52a Large Diameter 52b Small diameter part 53 Piercing punch 53a Large diameter part 53b Small diameter part

Claims (6)

[Claims] 1. A work made of a metal plate having a shaft rod insertion portion formed in advance and a bifurcated tightening portion projectingly formed on one side thereof is housed and clamped between a pair of holders. A first step in which a punching die is slidably accommodated between the bifurcated tightening portions, and a bolt insertion hole is punched in the one tightening portion from the one holder side by a punching punch; A second step of discharging the punching waste stored in the punching waste storage portion of the punching die by the first step by sliding the punching die, and a work in which the punching waste is discharged by the second step is a burring die. It is housed and held between holders, and the burring punch is pressed from the holder side through the bolt insertion hole and the other tightening portion is penetrated, and the work is pushed out into the cavity formed in the burring die. Made of a metal plate, which comprises a third step of forming a screw pilot hole with the ring portion and a fourth step of molding a screw portion in the screw pilot hole of the burring portion obtained in the third step. Method of forming thread part of yoke. 2. The punching die has a flat plate shape, the plate thickness of which is thicker than that of the workpiece, and the punching die is formed by penetrating through a punching scrap accommodating portion having a diameter larger than the diameter of the bolt insertion hole. A metal mold for forming the threaded portion of a characteristic metal plate yoke. 3. The burring die forms a concave cavity for forming a burring portion by a cooperation action with the burring punch on the work mounting side, and forms a through hole for inserting the burring punch continuously to the cavity. A metal mold for forming a threaded portion of a yoke made of a metal plate. 4. A work made of a metal plate having a preformed shaft rod insertion portion and a bifurcated tightening portion formed on one side thereof is housed and held between a pair of holders. A first step in which a punching die is slidably accommodated between the bifurcated tightening portions, and a bolt insertion hole is punched in the one tightening portion from the one holder side by a punching punch; A second step of discharging the punched dust stored in the punched dust storage portion of the punching die by sliding the punching die in the first step, and an embossing die and a holder for the work from which the punched dust is discharged in the second step. It is housed and sandwiched between them, and the embossing punch is pressed from the holder side through the bolt insertion hole to the other tightening portion to extrude the work into the cavity formed in the embossing die to form the embossing portion. First Step, and the work obtained in the third step is housed and sandwiched between the piercing die and the holder, and the piercing punch is pressed from the holder side through the bolt insertion hole while penetrating, And a fifth step of forming a threaded portion in the threaded pilot hole of the embossed portion obtained in the fourth step. Thread forming method. 5. A die for forming a threaded portion of a metal plate yoke, wherein the embossing die has a concave cavity for forming an embossed portion on the mounting side of a work by a cooperation action with an embossing punch. . 6. The metal plate according to claim 6, wherein the piercing die has the same cavity as the cavity of the embossing die on the work mounting side, and a through hole for inserting a piercing punch is formed continuously to the cavity. Mold for forming thread part of yoke.