JPS5915287B2 - Drawing processing method for synthetic resin sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for drawing synthetic resin sheets used, for example, in manufacturing instrument panels for automobiles.

Conventionally, this type of method is known in which a synthetic resin sheet is heated in advance to soften it, and then drawn and formed using upper and lower drawing dies. It is easy to stretch and cause damage.

The sheet may be, for example, a composite sheet consisting of a polyvinyl chloride or other leather sheet and a polypropylene foam or other foam sheet laminated one above the other, in which case the sheet is particularly susceptible to damage in the foam sheet. It's a win. The purpose of the present invention is to provide a method for eliminating such inconveniences, and after heating and softening a synthetic resin sheet made of a laminate of a leather sheet and a foam sheet, the upper and lower layers are then heated. The synthetic resin sheet is formed by drawing with a drawing die, and is characterized in that a slit or other incision is made in advance in the synthetic resin sheet at a portion corresponding to approximately the center of the valley of the drawing die.

An example of implementing the present invention will be explained with reference to the attached drawings.

In the drawings, reference numeral 1 denotes a synthetic resin sheet, and the sheet 1 is a composite sheet in which a polyvinyl chloride or other leather sheet Ia and a polypropylene foam or other foam sheet Ib are laminated one above the other. The sheet 1 is prepared in advance as shown in FIGS. 1 and 2.
As shown in the figure, it is prepared in a flat shape, then softened by heating, and then drawn and formed using upper and lower drawing dies to obtain the shape shown in the third figure, for example, which is different from conventional products. Although not particularly different, according to the present invention, slits or other incisions 2 are made in advance in the sheet 1, for example, as clearly shown in FIG. This cut 2 should be made particularly at the deep drawing or rim portion, that is, at the location where large elongation is expected, and thus the cut 2 will be deformed as shown in FIG. 3 or 4, for example, by drawing. In other words, it functions to eliminate large elongations in the remaining portion. F. The cut 2 is provided, for example, in the approximate center of the sheet 1 as shown in the figure, and this center part becomes a trough as shown in the third figure according to the drawing process described above, and this trough is removed in the next step. Therefore, the cut 2 does not appear on the product at all.

As described above, according to the present invention, slits or other incisions are made in advance in the synthetic resin sheet so that the elongation is absorbed during drawing forming, and an excellent product is obtained without damage such as cracks caused by localized large elongation. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a plan view of a synthetic resin sheet as an example of the method of the present invention;
FIG. 2 is a cutaway side view thereof, FIG. 3 is a sectional view after drawing and forming, and FIG. 4 is a plan view thereof. 1...Synthetic resin sheet, 2...Notch.

Claims (1)

[Claims] 1. In a method in which a synthetic resin sheet made of a laminate of leatherite and a foam sheet is heated to soften it, and then drawn using upper and lower drawing dies, the synthetic resin sheet is filled with the troughs of the drawing dies. A method for drawing a synthetic resin sheet, the method comprising making a slit or other cut in advance in a portion corresponding to approximately the center of the sheet.