JPS6178529A - Forging forming method of gear component having oil groove - Google Patents

Abstract

PURPOSE:To improve a productivity by forming the core burr caused on a shaft hole part with discriminating by making a step from an oil groove part, then by punching the core burr. CONSTITUTION:A lower die punch 16 being fitted to the knockout pin 17 taking out a work 1 is provided. A core burr 11 is formed with a step being made in the space with an oil groove part 10, due to the tip part of the lower die punch 16 projecting toward an inner punch 2. With said method the core burr is formed with only driving the lower die punch 16 onto the work 1, also the punching force for burr punching has no effect on the oil groove part 10 in case of forging. The oil groove part 10 does not need to receive the punch force therefore and the oil groove die is made disused. Furthermore the man- hour in the position setting work of the work 1 and punching die is eliminated and the productivity is improved together with the reduction in the work man- hour of a die.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for plastic working of gear parts, and more particularly to a forging method for imparting an oil groove shape to both end faces of the gear part.

[Prior art]

Oil grooves in gear parts used in automobile transmissions, etc.
Conventionally, a workpiece with a shaft hole has been provided by cutting, and although it is highly accurate, there is a problem that the number of man-hours increases. Therefore, the present inventors developed a JA forging method for gear parts.
Therefore, we came up with the idea of adding oil grooves to both end surfaces of the shaft hole of the workpiece at the same time as forming the shaft hole. However, in the method initially attempted, a core burr was formed on the die side end surface of the workpiece, including the groove portion KI' [11], and the core burr was punched out in the first step.

FIG. 4 shows a cross-sectional view of the step @1 above.

1 is work, 2 is inner bread f-13 is outer pa/chi,
4 keys/no die, 5 indicates the ejector, and 6 indicates the outer die. On the end face of the ejector 5.

The oil groove type 7 as shown in the plan view of FIG. 5-(a) and the side view of FIG. 5-(b) is provided, and the outer punch 3 is also provided with a similar oil groove type. be. Then, when the inner pan-y-2 and the outer bunch 3 operate, the outer shape and the shaft hole 8. Oil grooves 9 and 10 are formed, and a core burr 11 is formed on the die side end surface including the oil grooves 10t.

FIG. 6 shows a sectional view of the deburring process, in which the deburring punch 12 and the deburring die 13 Vi are all shown. As shown in the plane l of FIG. 7-(a) and the cross-sectional view of FIG. 7-(b), an oil groove mold 15 is provided around the punching hole 4 of the punching die 3 to receive the pressure of the work l forming a surface. This is because if such a pressure receiving surface were not provided, the oil groove portion 10 would be deformed during deburring. Therefore, when removing firmness, it is necessary to take the time to align the oil groove part 10 of the work l and the oil groove mold 15.
When activated, the oil groove 1 is cut in the process of cutting the core burr 11.
Deformation due to shear force occurs at 0.

[Problem that the invention seeks to solve]

In view of the above-mentioned problems, the present inventors would like to provide a forging method capable of imparting an oil groove or a shape similar to an oil groove to gear parts, etc., without requiring alignment between a workpiece and a die in the deburring process. That is.

[Means for solving the problem] The present inventors have changed the position of the core burr, which was conventionally formed on the die side end face of the workpiece including the oil groove, to the inside of the workpiece away from the oil groove. By moving it to the oil groove, the shearing force during deburring was prevented from reaching the oil groove. That is, in the forging method of the present invention, when compression forging a gear part, oil grooves are simultaneously forged on both end surfaces of the shaft hole of the workpiece, and core burrs generated in the shaft hole by this forming are removed from the oil grooves. The shaft hole is formed by punching out the core burr and forming the shaft hole.

[Effect]

In order to form the core burr inside the workpiece as in the present invention, a lower punch is provided in the lower die so as to face the inner bunch, and the lower punch is driven into the workpiece during forging. With K in this way, the impact force during deburring will not affect the oil groove, and there is no need for the oil groove mold to receive the force exerted on the oil groove as in the conventional method. There is no need to provide And since the thickness of the core burr is thin, it is easy to remove the burr. These actions and effects are wide-ranging and can be applied when giving groove shapes to forged perforated parts! I toadashi.

It is not just limited to gear parts.

〔Example〕

Hereinafter, one method of the present invention will be explained based on the drawings.

Using a drum-shaped rough base formed for manufacturing gear parts,
The shaft hole and the oil groove are simultaneously formed using the forging die shown in Fig. 1. This forging die is provided with a lower die punch 16 fitted with a knockout bin 17 for taking out the workpiece 1 in place of the siege ejector 5, which has a different die structure from that shown in FIG. protruding towards.

Therefore, the core burr 11 is formed with a step between it and the oil groove portion 10.

FIG. 2 shows a plan view of the end surface of the die side of the work 1 formed as described above, and FIG. half is t)
In FIG. 1, a indicates the depth of the oil groove portion 10, and b indicates the distance from the end surface 18 to the core burr 11. If the dimensions of the inner bunch 2 and the lower die punch 16 are determined so as to achieve b)a in this way, the core burr 11 will be formed with a step difference from the oil groove part 10, and the shear force when punching the core burr 11 will be reduced. It is possible to prevent the oil from reaching the oil groove portion 10.

〔Effect of the invention〕

As described above, according to the present invention, the oil groove of the workpiece is not affected by the shearing force during core burr punching, so there is no need to provide the punching die with a pressure-receiving surface that supports the oil groove, and therefore the position of the workpiece and the punching die is There is no need for matching, and it is possible to improve the forging work.

In addition, since the forging die for implementing the present invention has a single-wire die shape for the deburring process, the number of die processing steps is reduced, and together with the above effects, productivity is significantly improved. Surutsu

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of a forging die using an example button. Figure 2 shows a plan view of one side of the molded product, and Figure @3 shows the top view of one side of the molded product.
In the figure, a rotational sectional view in the human direction is shown. FIG. 4 shows a cross-sectional view of a forging die used in the conventional method. Figure 5-(a) is a plan view of the ejector, Figure 5-(b)
also represents a side view. FIG. 6 shows a cross-sectional view of the core deburring process. Figure 7-(a) is a plan view of a conventional punching die, Figure 7-
(B) also shows a cross-sectional view.Work 2...Inner punch 3...
Outer punch 4...Inner die 5...Ejector 6--Outer die...Oil groove type 8
... Shaft hole part 9.10 ... Oil groove part 11 ... Core burr 12 ... Punching bong f 13 ... Punching die 14, ... Punching hole 15 ... Oil groove mold 16
...Dingle punch 17...Knock outer pin 1
8... End face Figure 1 Figure 2 Figure A'' Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] When compression forging gear parts, oil grooves are simultaneously forged on both end surfaces of the shaft hole of the workpiece, and core burrs generated in the shaft hole due to the forming are removed in areas that have a step with the oil groove. A method for forging a gear part having an oil groove, the method comprising forming the shaft hole, and then punching out the core burr to form the shaft hole.