JPS6335343B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a hollow part with a tip drawing using a multi-stage heading machine.

Conventionally, a multi-stage heading machine has a head side mold and a shaft side mold, as shown in FIGS. 1 and 2. The head side mold consists of three molds: a first punch 4, a second punch 5, and a third punch 6, and the shaft side mold consists of two molds: a drawing die 7 and a receiving die 8. It is made up of individual molds.

The first punch 4 is composed of a pin for pushing a cut wire material 14 into the first inner 11. The second punch 5 is a mold for preforming the head 17, and the mold includes a recessed hole 25 corresponding to the preliminary shape of the head 17 and a through hole communicating with the recessed hole 25. 9 is provided. A punch pin 10 is slidably inserted into the through hole 9. Furthermore, the third punch 6 is
This is a mold for finishing molding the head 17, and a recessed hole 25 having the same shape as the finished product shape of the head 17 in the hollow part 15 is carved in the mold.

The first punch 4, second punch 5, and third punch 6 configured as described above each have a drawing die 7.
and are arranged to correspond to the receiving die 8.

On the other hand, the drawing die 7 is arranged corresponding to the first punch 4, and in front of the drawing die 7,
The first inner 11 is press-fitted. A first forming hole 22 having the same shape as the drawing shape of the shaft portion 16 in the hollow part 15 is carved in the first inner 11, and the drawing die 7 and the first inner 11 have a first forming hole 22 formed therein.
A first speed through hole 31 passing through both is provided. A protruding pin 12 that regulates the entire length of the material 14 is slidably inserted into the first communication hole 31 . Further, the receiving die 8 is arranged corresponding to the second punch 5 and the third punch 6, and a second inner 32 is press-fitted in front of the receiving die 8. The second inner 32 includes a hollow part 15
A second piece having the same shape as the finished product shape of the shaft portion 16 in
A forming hole 33 is formed, and the receiving die 8 and the second inner 32 are provided with a second communicating hole 34 that passes through them. A drilling pin 13 for drilling a hollow hole 18 at the tip of the shaft portion 16 is slidably inserted into the second communication hole 34 . The punching pin 13 has a tip portion 24 and a relief portion 23.

When manufacturing a hollow part with a drawn end using the multi-stage heading machine configured as described above, as shown in FIG. The material 14 is pushed into the first forming hole 22 in the first inner 11 with the punch 4, and the tip of the material 14 is drawn. At this time, the aperture length is regulated by the protruding pin 12. Therefore,
When the first punch 4 retreats, the ejecting pin 12 moves forward to eject the material 14 from the first inner 11. Further, the material 14 is transferred to a position in front of the receiving die 8 by a transfer device (not shown).

Next, as shown in FIG. 1B, the second punch 5 moves forward, and the second punch pushes the material 14 into the second forming hole 33 in the second inner 32, and the punching pin in the receiving die 8. 13, a hollow hole 18 is bored at the tip of the material 14. At the same time, the second punch 5 preliminarily forms a head 17 at the rear end of the material 14 using the punch pin 10.

Furthermore, as shown in FIG. 1C, the second punch 5
moves backward, and the third punch 6 moves forward in its place, and the third punch 6 inserts the head 17 into the rear end of the material 14 inserted into the second forming hole 33 in the second inner 32.
Perform final molding.

Then, when the shaping of the head 17 is completed and the third punch 6 retreats, the punching pin 13 moves forward, and the hollow part 15 as shown in FIG.
The hollow part 15 that is extruded out is carried out of the machine by a separating device (not shown).

By the way, in the above manufacturing method, the shaft portion 1
After drawing the shaft end of 6, the end surface of the shaft portion 16 is drilled by a backward extrusion method without restraining the end surface in any way, so the end surface of the shaft portion 16 has poor flatness. There is a drawback that burrs 19 are generated around the hollow hole 18.

Therefore, for ordinary hollow parts 15, the accuracy obtained by the above method is sufficient, but for those that require particularly high precision, after manufacturing by the above method, a separate cutting process is performed. There was no choice but to improve accuracy. Therefore, there are drawbacks such as high manufacturing costs.

The present invention is aimed at eliminating the above-mentioned drawbacks, and embodiments will be described below with reference to the drawings.

In FIGS. 3 and 4, 1 is a multi-stage heading machine, which has a head side mold and a shaft side mold. The head side die is made up of a first punch 4, a second punch 5, and a second punch 6, and the shaft side die is made up of a first receiving die 20 and a second receiving die 21. The first punch 4 is composed of a pin for pushing the cut wire material 14 into the first receiving die 20.

Next, the second punch 5 is a mold for preforming the head 17, and the second punch 5 includes:
A pre-shaped recessed hole 25 of the head 17 and a through hole 9 communicating with the recessed hole 25 are provided. A punch pin 10 is slidably inserted into the through hole 9.

Further, the third punch 6 is a mold for finishing molding the head 17, and the third punch is provided with a recessed hole 25 having the same shape as the finished product shape of the head 17 in the hollow part 15. ing.

The first punch 4, second punch 5, and third punch 6 configured as described above are arranged to correspond to the first receiving die 20 and the second receiving die 21, respectively.

On the other hand, the first receiving die 20 has a first punch 4
are arranged corresponding to the first receiving die 2.
A first inner 11 is press-fitted in the front.
A first forming hole 22 having the same diameter as the shaft diameter of the shaft portion 16 in the hollow part 15 is formed in the first inner 11, and the first receiving die 20 and the first inner 11 are A first communication hole 31 having the same diameter as the shaft tip diameter of the first forming hole 22 is provided.
A protruding pin 12 is inserted into the first communicating hole 31, and a punching pin 13 for drilling a hollow hole 18 at the tip of the material 14 inside the protruding pin 12.
is slidably held.

Further, the second receiving die 21 has a second punch 5.
and the third punch 6, and a second inner 32 is press-fitted in front of the second receiving die 21. The second inner 32 is
It consists of a front inner 26 and a rear inner 27. A second molded hole 33 having the same shape as the shaft length and shape of the shaft portion 16 in the hollow part 15 is carved in the front inner part 26.
The receiving die 21 and the rear inner 27 are provided with a second communication hole 34 having a diameter slightly smaller than the minimum diameter of the aperture side of the front inner 26 . A molded pin 28 is slidably inserted into the second communication hole 34, and the molded pin 28 is inserted into the tip portion 2.
4 and a tapered portion 29, and the tip portion 24 has the same shape as the hollow hole 18.

Using a multi-stage heading machine configured as above,
When producing a hollow part with a drawn end from a cut wire material, first cut the wire material to a predetermined size, and as shown in FIG. 1st inner 1
1 into the first molding hole 22. At the same time,
A hollow hole 18 is drilled at the tip of the material 14 by the pin 13
Perforate by. When the drilling of this hollow hole 18 is completed, the first punch 4 retreats, and the first punch 4
Only the ejection pin 12 in the first receiving die 20 moves forward in conjunction with the operation of
is transferred to a position in front of the second die 21 by a transfer device (not shown).

Next, as shown in FIG. 3B, the second punch 5 moves forward and forces the material 14 into the second forming hole 33 in the front inner 26. At the same time, the head 17 is preformed at the rear end of the blank 14 by the punch pin 10 in the second punch 5. On the other hand, at the tip of the material 14, a forming pin 28 in the second receiving die 21 is inserted into the hollow hole 18, and the forming pin 28 maintains the shape of the hollow hole 18 without deforming. At the tip of 18, when inserting the forming pin 28,
Chamfering 3 by the tapered portion 29 of the forming pin 28
0 processing is applied.

Furthermore, as shown in FIG. 3C, the shaft portion 16
When the forming is completed, the second punch 5 retreats, and the third punch 6 moves forward in its place;
Finish molding of the head 17 is performed on the rear end of the material 14 inserted into the second molding hole 33 in the front inner 26.

When the shaping of the head 17 is completed and the third punch 6 retreats, the shaping pin 28 moves forward and the hollow part 15 as shown in FIG.
The hollow part 15 that is extruded out is carried out of the machine by a separating device (not shown).

As explained above, in the present invention, the hollow hole drilling process and the tip drawing process are configured as a series of manufacturing processes, so that when the hollow hole is bored, the end face of the shaft part is The flatness of the machine will not deteriorate, burrs will not occur around the hollow hole, and there will be no need for additional finishing during cutting, and the product will improve the receiving die etc. of conventional machines. This has the effect of being able to supply products of stable quality at low cost.

Since the present invention has a forming pin, it is possible to perform processing while maintaining the existing hollow hole shape, especially when drawing the tip, and it is also possible to chamfer the tip of the hollow hole, resulting in end surface accuracy. This has the effect of being able to provide products with high quality.

[Brief explanation of the drawing]

Figures 1A, B, and C are manufacturing process diagrams of a conventional hollow part, and Figure 2 is a completed diagram of a conventional hollow part.
3A, B, and C are manufacturing process diagrams of the hollow part according to the present invention, and FIG. 4 is a completed diagram of the hollow part according to the present invention. 1...Multi-stage heading machine, 4...First punch, 5...
...Second punch, 6...Third punch, 7...Drawing die, 8...Receiving die, 9...Through hole, 10...Punch pin, 11...First inner, 12...Ejection pin, 13... ...Punching pin, 14...Material, 15...
...Hollow part, 16...Shaft part, 17...Head, 18
... Hollow hole, 19 ... Burr, 20 ... First receiving die, 21 ... Second receiving die, 22 ... First forming hole, 23 ... Relief part, 24 ... Tip part, 25 ...
Recessed hole, 26... Front inner, 27... Rear inner, 28... Molded pin, 29... Taper part, 30
... Chamfer, 31 ... First communication hole, 32 ... Second
Inner, 33...second molding hole, 34...second communication hole.

Claims (1)

[Claims] 1. A raw material 14 made of a cut wire is pushed into the first inner 11 by the first punch 4, and a hollow hole 18 is bored at the tip of the raw material 14 by the punching pin 13 in the first receiving die 20. , further, the material 14 is
Push the material 14 into the front inner 26 with the punch 5, insert the forming pin 28 in the second receiving die 21 into the hollow hole 18 of the material 14, and while holding the material 14, insert a diaphragm into the tip of the material 14. A method for manufacturing a hollow part, characterized in that a shaft portion 16 is molded. 2. Connect the molded pin 28 to the tapered part 29 and the hollow hole 1.
8 and a tip portion 24 having the same shape.