JP2898074B2 - Manufacturing method of cylindrical parts - Google Patents

Description

The present invention relates to a method for manufacturing a cylindrical part.

[Prior Art] Cylindrical parts formed by drawing require a refining treatment, and the deformation during the refining treatment is large, and the required roundness cannot be obtained in many cases.

[Problems to be Solved by the Invention] Deformation during the refining process can be prevented by increasing the rigidity of the cylindrical component, and a method of integrally forming the flange portion is considered as a means for that. However, deformation during the tempering process is not prevented only by forming a small amount of flange,
In order to surely prevent deformation, it is necessary to increase the amount of flange. On the other hand, when the amount of flange is increased,
After the tempering treatment, it is necessary to remove an excess flange portion by press shearing or by turning. In this case, since the flange portion is hardened through the tempering treatment, it is difficult to process the flange portion, and the cost is increased.

Further, as a means for preventing deformation during the tempering process, a method of integrally forming a bottom with a cylindrical part (forming the cylindrical part into a cup shape) may be considered. A similar problem arises.

Therefore, an object of the present invention is to provide a manufacturing method that can reliably prevent deformation of a cylindrical component during tempering treatment and that can be easily implemented.

[Means for Solving the Problems] In the present invention, a portion (a flange portion, a bottom portion, and the like) for preventing deformation during a tempering process is integrally formed on a cylindrical component by drawing, and the drawn cylinder is finished. The above-mentioned deformation preventing portion of the shaped part is subjected to a shearing process with a punching amount equal to or less than the thickness of the portion (hereinafter referred to as a half punching process), and the same portion is subjected to a shearing process again after the tempering process to thereby prevent the deformation. The application portion was removed by shearing.

[Operation] Since the rigidity of the cylindrical component is increased by integrally forming the flange portion and the bottom portion, deformation during the refining process is prevented. This deformation preventing portion (flange portion, bottom portion, etc.) is subjected to a half blanking process before the tempering process.

Taking the case where the flange portion is integrally formed as the deformation preventing portion as an example, the half punching is performed by a punching amount smaller than the thickness dimension W1 of the flange portion (hereinafter, half punching) as shown in FIG. 2 (b). Flanged part (1a)
Is subjected to shearing. Since the half-blanking amount W2 is set to be smaller than the wall thickness dimension W1, the flange portion (1a) has not yet been sheared at the time of performing the half-blanking process. If the heat treatment is performed in this state, the original purpose of preventing the flange portion from being deformed during the heat treatment can be achieved. On the other hand, when the flange portion is to be removed by shearing after the tempering process, the shearing process for the half-blanking amount W2 has been performed in advance, so the remaining portion may be subjected to the shearing process. Therefore, even if the hardness of the flange portion is high, the shearing force required for shearing can be small.

[Embodiment] Hereinafter, an embodiment in which a flange portion is integrally formed as a portion for preventing deformation during a tempering process on a cylindrical component will be described.

FIG. 1 shows a cylindrical part formed through a predetermined drawing step. On one end surface of the cylindrical portion (1) of the cylindrical part, a flange portion (1a) for preventing deformation during the tempering process is integrally formed. Before this tempering treatment,
As shown in FIG. 2, half blanking is performed. In general, when shearing a metal material, both cutting edges of the punch (2) and the die (3) enter the material due to shear force,
After a certain degree of plastic deformation of the material, the material is cracked from the cutting edge to complete the shearing. Half punch amount
W2 is desirably about the maximum stroke amount of the punch (2) within the plastic deformation region of the material, but in practice, the funnel portion (1a)
In consideration of the wall thickness W1 and the clearance C between the punch dies (2) and (3), an amount that can finally achieve the optimum roundness is experimentally obtained. For example, in FIG. 2, W1 = 1.
In the case of 8 mm and D = 95.7 mm, it has been experimentally confirmed that the optimum roundness can be obtained when the half-blanking amount W2 = 0.6 mm and the clearance C = 0.15 mm.

The half-blanked cylindrical component is subjected to a tempering process and then subjected to a finish blanking process. As shown in FIG. 3, the finish punching is performed to re-shear the portion A where the half punching has been performed to completely shear the flange portion (1a). Already half cut amount W2
, The finish punching may be performed on the remaining amount of the half punching. For this reason, even if the hardness of the flange portion (1a) is high, it can be sheared with a small shearing force.

On the shearing surface (1c) of the flange portion (1a), broken portions, burrs, etc. remain. Therefore, in order to finish the shear surface (1c) smoothly, tumbler processing is performed as finishing processing.

[Effects of the Invention] The present invention forms a part for preventing deformation at the time of heat treatment on a cylindrical part, and performs a half-blanking process on the deformation prevention part before the heat treatment, After the quality treatment, the same part was subjected to shearing again. For this reason, according to the present invention, extremely good roundness can be obtained without deformation during the refining process, and the above-mentioned deformation preventing portion hardened by the refining process can be easily removed. Thereby, the accuracy of the product is improved and the processing cost is reduced.

In addition, the half blanking process of the present invention exerts the same effect as described above for general members that need to perform a shearing process after the tempering process, and reduces deformation during the tempering process as exemplified in the embodiment. In addition to a cylindrical part integrally formed with a flange part for preventing the same, for example, a cylindrical part integrally formed with a bottom part (formed into a cup shape) for preventing deformation during the refining process is similarly applied. It is possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a cylindrical part integrally formed with a flange portion. FIG. 2 (a) is a cross-sectional view showing a state where a half blanking process is performed, and FIG. 2 (b) is FIG. 2 (a). Fig. 3 is a cross-sectional view showing a state in which the shearing is completed. 1 ... cylindrical part, 1a ... flange

Claims (1)

(57) [Claims] 1. A part for preventing deformation during a tempering process is integrally formed on a cylindrical part by drawing, and the deformation preventing part of the drawn cylindrical part is replaced with a thickness dimension of the part. A method for producing a cylindrical component, wherein a shearing process is performed in the following amount, and the same portion is subjected to a shearing process again after the tempering process so that the deformation preventing portion is removed by shearing.