JPS6233018A - Drawing method for hemispheric parts - Google Patents

Abstract

PURPOSE:To stably draw without wrincles and breakings by pushing out a blank on a female metallic mold by a hydraulic forming to form a hemispheric work, then pushing it into a die to form by a punch supporting the under part with soft materials such as rubber, etc. CONSTITUTION:The blank 1 petted on the die 2 is pressed by a lid 3 and by feeding pressurized oil through a hole 6 to form a hemispheric work projected into the die hole 2 without wrinkles and flaws. Then, a soft materials such as rubber 9, etc. is pushed under this hemispheric work by the hydraulic cylinder 11 and indented by the punch 7 into the die hole 2 to form. The tension of blank 1 at the tip of the punch 7 is reduced by friction force between the punch 7 and the blank 1 to decrease thinning. Therefore, even the hemispheric part is large sized, the drawing is stably performed without causing flaws and breakdowns on the blank 1.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a drawing method for hemispherical parts.

[Conventional technology]

Traditionally, drawing of hemispherical products using punches and dies is
If the (plate thickness/blank diameter) is small, body wrinkles will occur,
Processing was difficult. For this reason, hydroforming using hydraulic pressure, opposed hydraulic deep drawing, or marforming using rubber are used.

[Problem that the invention seeks to solve]

Body wrinkles occur when forming using punches and dies. Furthermore, molding methods such as hydroforming that can prevent the occurrence of body wrinkles are limited to the production of small parts and cannot be applied to large parts because the machine capacity is large relative to the processing diameter.

SUMMARY OF THE INVENTION An object of the present invention is to provide a molding method that solves two or more problems of the conventional molding method, can be applied to large parts, and can suppress the occurrence of body wrinkles.

[Means for solving problems]

In order to achieve this objective, the process was divided into two areas where problems occurred. In other words, the first step is to perform hydraulic molding using a female mold.
and a second step in which the hemispherical object formed in the first step is pushed into a die using a punch while supporting the lower part with a soft material such as rubber.

[Effect]

In the first step, only tensile force is applied to the blank, and no body wrinkles occur. In the second process.

The blank is further processed while being held by the punch and the elastic material.

〔Example〕

FIG. 1 shows an outline of hydraulic molding using a female mold as the first step. The blank 1 rests on the die 2 and has a lid on it. The clearance between the die 2 and the lid 3 is defined by a spacer 5. The lid 3 has a hole 6 for introducing pressure oil. Pressure oil acts on the blank 1, and the blank 1 is squeezed. When the drawing depth reaches 1/2 to 1/3 of the predetermined hemisphere, the lid 3 is removed and the first step is completed.

Note that the drawing depth varies depending on the material, and for those with little elongation, it is approximately '/2. For 5tys304 etc., about 2/3 is good.

(Note: E3US 3 Q 4 can be formed into a hemispherical shape using only the first mold, but the amount of thickness loss will be large.) Figure 2 shows
After the first step, a second step is shown in which the product is pressed into a predetermined shape using a punch 7. At this time, in order to reduce the tension acting on the tip of the punch 7, the rubber 9 is pressed by a hydraulic cylinder 11 via a rod 10. Therefore, according to the push of punch 7,
The hydraulic cylinder 11 is pushed back and the blank 1 is pushed back by the punch 7.
is held between the tip of the rubber 9 and the rubber 9.

〔Effect of the invention〕

According to the present invention, the first step is hydroforming.

Since the blank is deformed by pressure, only tensile force acts on the blank, and no body wrinkles occur. Therefore, in the second step, the drawing process may be performed to an extent that no body wrinkles occur. In this second step, the blank is held and processed using a punch and an elastic material.
The blank tension generated at the tip of the punch is reduced by the frictional force between the punch and the blank, reducing the amount of thinning. Therefore, stable drawing can be performed without causing any breakage in the blank.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the first step in the second embodiment of the present invention, and FIG. 2 is a schematic diagram showing the second step in the embodiment of the present invention. l blank, 2: die, 6: pressure oil supply hole, 7: punch, 9: rubber, 11: hydraulic cylinder. Shiku 1 Zumyo 2nd Ward

Claims (1)

[Claims] The first step is to perform hydraulic molding using a female mold, and the second step is to press the hemisphere formed in the first step into a die using a punch while supporting the lower part of the hemispherical object with a soft material such as rubber. A method for drawing hemispherical parts, characterized by comprising two steps.