JPS6230857B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a deformed bolt, and particularly to a method of manufacturing a bolt of a special shape as shown in FIG.

The bolt shown in FIG. 8 has a round bar 30 on one side centering on a collar 32 and a short fence plate 38 on the other side on the same axis, and has a thread 33 carved on the round bar 30, which is different from conventional manufacturing. cannot be manufactured easily by this method.

For example, conventionally, as shown in FIG. 9, a square steel e is first cut to form a member having a shape that integrates a round bar a and a short fence c. Next, a donut-shaped annular body g with a center hole f close to the outside diameter of the round bar a is fitted onto the round bar a, and the annular body g is moved to the boundary between the round bar a and the flat plate c. A method of welding to rod a has been considered.

The present invention provides a method for manufacturing a special-shaped bolt that can manufacture the above-mentioned complicated-shaped bolt through a simpler process than the conventional method, and has great advantages in terms of strength without cutting the streamlines. The purpose is to provide.

Next, an example will be described. The method of the present invention includes <A> a molding process using a press, and <B>
It consists of a forging process.

[A] Press forming process <1> Primary processing First, a wire rod is cut into a predetermined length to produce the raw material 4.

The die 5 for primary processing passes through a large-diameter through-hole 7 whose diameter is slightly larger than the diameter of the material 4, and a small-diameter portion 8 partially narrowed to a small diameter is formed in the middle of the through-hole 7.

Then, a die side knockout pin 9 having an outer diameter approximately equal to the inner diameter of the small diameter portion 8 is positioned at the outer end of the large diameter hole 7.

On the other hand, the punch 10 for primary processing has a shallow large diameter hole 11 slightly larger than the diameter of the material 4,
The peripheral edge of the entrance of this large diameter hole 11 forms a mortar-shaped slope 12 whose diameter is gradually enlarged, so that the material 4 is inserted smoothly during operation.

During processing, the material 4 is transferred to the center of the die 5 and punch 6 for primary processing, and the punch 1
0 approaches die 5 under pressure, material 4
One end of the punch 10 is first fitted into the large diameter hole 11 of the punch 10.

In this state, when the punch 10 moves forward, the material 4
The distal end side is press-fitted into the large-diameter through hole 7, is squeezed by the small-diameter portion 8, and advances until just before the distal end contacts the pin 9, and then stops.

As a result, the raw material 4 is formed into a rod-shaped first workpiece 15 having a diameter smaller than that of the small diameter part 8 and having a large diameter part 13 and a small diameter part 14 .

<2> Secondary processing (Figs. 3 and 4) As shown in Fig. 3, the die 16 for secondary processing has an inner diameter that is approximately equal to the small diameter part 14 of the first workpiece 15, and a length that is longer than the small diameter part 14. A short second machining hole 17 is provided, and a through hole 18 having a diameter somewhat smaller than the inner diameter of the second machining hole 17 is penetrated toward the rear end of the die 16 at the deepest end of the second machining hole 17 .

A small diameter portion 19 having a reduced diameter is formed in the middle of the second processed hole 17.

Also, a knockout pin 2 is provided in the through hole 18.
0 slidably inserted.

On the other hand, the punch 21 for secondary processing has a large diameter portion 2 larger than the outer diameter of the first workpiece 15 from the entrance side.
2. A first inclined cylinder 2 having a medium diameter portion 23 and a small diameter portion 24, and between the large diameter portion 22 and the medium diameter portion 23, the inner diameter gradually becomes smaller as the depth increases.
5, and a similar second inclined cylinder 26 is provided between the medium diameter portion 23 and the small diameter portion 24, respectively.

A knockout pin 2 is located deep in the small diameter portion 24.
7, and an enlarged hole 29 is formed around the knockout pin 27 by a distance l by which a flange plate 28 protruding like a flange moves.

During secondary processing, the small diameter portion 14 of the first workpiece 15 is positioned toward the second processing hole 17 of the die 16 for secondary processing (as shown in FIG. 4), and the punch for secondary processing is 21 die 1
6 by approaching the first workpiece 15
The small diameter portion 14 is narrowed within the second machined hole 17 to form a threaded shaft 30 of the bolt.

On the other hand, the large diameter part 13 includes the large diameter part 22 of the punch 21 for secondary processing, the first inclined cylinder 25, the medium diameter part 23,
The second inclined cylinder 26 is deformed to match the shape of the small diameter portion 24, and is compressed to have a diameter larger than that of the first processed body 15, thereby forming a bolt head shaft 31 located via the screw shaft 30 and the collar 32. and conical shafts 34, 3 at positions corresponding to the inclined cylinders 25, 26.
5 is formed.

Further, the free end side of the screw shaft 30 is formed with a threaded portion 33 whose diameter is reduced to a small diameter by the small diameter portion 19 .

After the punch 21 is separated from the die 16, the knockout pin 20 of the die 16 kicks out the screw shaft 30 from the die 16. Furthermore, the knockout pin 27 of the punch 21 connects the head shaft 31 with the punch 2.
Push out from 1. (Fig. 5) In the above process, the die 21 for secondary processing is used.
Although the structure in which the inclined tubes 25 and 26 are provided inside has been described, this structure is formed in order to completely separate the die from the product even when the stroke l of the knockout pin 27 of the die is small.

Therefore, when the stroke l is long, the inclined cylinders 25 and 26 are unnecessary, and the head shaft 31 may be an equal diameter cylinder having a smaller diameter than the collar 32.

[B] Forging process (Fig. 7) Place the head shaft 31 of the second workpiece on the workbench 36 up to the boundary with the collar 32, and then insert the hammer 3 from above.
Drop 7.

As a result, the cylindrical head shaft 31 is formed into a short fence-shaped rectangular plate 38, and the metal crystals are destroyed and become fine grains, so that the quality of the material is improved.

After the forging process, a thread is cut in the threaded part 33,
Holes 39 are formed in the rectangular plate 38 if necessary. (Fig. 8) As described above, when manufacturing a bolt having a threaded shaft on one side of the collar plate and a rectangular short fence plate on the other side, the present invention provides: (1) using the first die and punch; , a first workpiece having a large diameter part and a small diameter part is pressed, and (2) a second die is used to stamp a threaded part with a diameter smaller than the diameter of the small diameter part at the tip of the small diameter part of the first workpiece. At the same time, the second punch presses the large diameter part of the first workpiece into the collar and head shaft, and (3) the head shaft is then struck with a hammer and forged into a rectangular plate. be.

Therefore, compared to the method of cutting the screw shaft and rectangular plate from steel and welding the flange, the manufacturing process is simpler and mass production is possible, and since the flow is not cut, good results can be obtained in terms of strength. .

[Brief explanation of the drawing]

Figures 1 to 5: Explanatory diagram of the press forming process of the present invention, Figure 6: Side view of the state after press forming, Figure 7: Explanatory diagram of the forging process, Figure 8: Perspective view of the final product. , FIG. 9: An explanatory diagram of a conventional manufacturing method. 15: First processed body, 13: Large diameter part, 14: Small diameter part, 30: Screw shaft, 31: Head shaft, 32: Tsuba, 3
8: Short fence board.

Claims (1)

[Claims] 1. When manufacturing a bolt having a screw shaft on one side of the collar plate and a rectangular short fence plate on the other side, (a) a large diameter portion and a small diameter portion are formed by a first die and a punch; (b) Next, using a second die, simultaneously stamp a threaded part with a smaller diameter than the outside diameter of the small diameter part on the tip side of the small diameter part of the first workpiece. In the second punch, the large diameter part of the first workpiece is pressed into the collar and head shaft, and (c) the head shaft is then hit with a hammer to forge a short fence plate to create a deformed bolt. Production method.