JPS59225830A - Working of drawn flange part by suppressing shear droop - Google Patents

Abstract

PURPOSE:To suppress considerably the shear droop in a flange corner part by making the shoulder radius of a drawing die zero, making the clearance between a punch and a die smaller than the thickness of a plate and forcing the metal in the drawn part by drawing into the flange part. CONSTITUTION:A shoulder radius is provided to a die and a plate material is drawn by the die, by which the drawing inside diameter and drawing height are finished to prescribed sizes in a step 1. The space between a punch 1 and a die 3 is set smaller than the thickness of a material to be worked and a product formed in the step 1 is held down by a punch 1 and a knock-out 4 to make the shoulder radius of the die 3 zero and to force the metal in the drawn part to the part A of the flange and at the same time the metal is extruded to the corner part B, by which the shear droop is prevented. A taper O is provided to the die 3 in order to force effectively the cut-off metal to the flange part. The product suppressed with the shear droop in the flange corner part is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drawing process that extremely suppresses flange sag during the drawing process.

In the past, there have been many examples of drawing process, but there is no known one in which the sagging of the flange part is extremely suppressed. In conventional drawing die processing, a radius was formed on the shoulder of the drawing die, as shown in Figure 1, to prevent cracks during drawing and die cutting.

In the case of such a processing method, large sag will certainly occur. Mechanically, when using the flange corner part, it is necessary to be careful of slippage due to sagging, and the appearance also looks quite poor if the sag is large.

Therefore, especially in such cases, it is necessary to suppress sag.

The present invention eliminates this drawback and has two steps in the processing sequence. Step 1 is the same as the conventional drawing method, and Step 2 uses a die that does not have a shoulder radius and the gap between the punch and the die is set smaller than the thickness of the workpiece material. This invention provides a method for suppressing some sagging, and will be described in detail below based on Examples.

The present invention is divided into Step 1 and Step 2.

Figure 1 explains each part of the drawing die and step 1.
1 is the punch, 2 is the wrinkle presser, 3 is the die, 4 is the knockout, 5 is the shoulder radius of the die, and 6 is the gap between the punch and die. Step 1 is to apply a shoulder radius to the die 3 and draw it as usual, and at this stage, the inner diameter and drawing height of the die 3 are finished to predetermined dimensions. FIG. 2 explains the sag suppression process in step 2 according to the drawing depth. The gap between the punch 1 and the die 3 is set to be smaller than the thickness of the workpiece. In order to prevent the product molded in step 1 from deforming, the inside of the product is pressed down with punch 1 and knockout 4.

When the ironing process begins, the scrap radius of the die 3 is zero, so the meat is scraped off and pushed into the A part of the flange. At this time, the meat is pushed out to part B of the flange corner and sag is suppressed.

The die 3 is also provided with a taper θ for the purpose of more effectively pushing the scraped meat into the flange. Depending on the degree of sagging, the die shoulder radius is set to zero in step 2 as seen in the examples above.
By using a die in which the gap between the punch and die is smaller than the thickness of the workpiece, and by pushing the meat into the flange,
It is possible to provide a product with suppressed sag at the flange corner portion.

[Brief explanation of drawings]

FIG. 1 is a diagram showing step 1 and each part of the drawing die. FIG. 2 is a diagram showing the ironing process in step 2. 1... Punch 2...Wrinkle presser 6...Dice 4...Knockout 5...Dice shoulder radius 6...The gap between punch and die or higher Applicant: Suwa Seikosha Co., Ltd. Agent Patent Attorney Mogami

Claims (1)

[Claims] In the drawing process of plate materials, the shoulder radius of the drawing die is set to zero, the gap between the punch and the die is made smaller than the thickness of the plate, and the meat of the drawing part is pushed into the flange part, thereby extremely suppressing sag. Sag suppression processing on the drawing flange.