JP2001079623A - Method for blanking thin thickness parts with progressive press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress shear droop and deformation generated at the time of press blanking and to improve production by restraining and half blanking a material which is fed progressively with an upper die and lower die and feeding it to the next stage as it is in that state and blanking out it. SOLUTION: In the restrained blanking, first, a material 11 to be worked is pressed down with the die 12 and ejector 13 of the lower die and stripper 14 of the upper die by spring pressure. As the upper die is lowered, the hole on the material 11 to be worked is restrained with a mandrel 15 and punch 16. Because the material 11 to be worked is wholly restrained, even when the material is blanked in that state, the generation of deformation and camber is suppressed. In a progressive die assembly, the material is made in a half blanked state providing an unblanked part of about 0.5 mm, for example, sent to the next stage and blanked out. At this time, because the clearance of about 0.02 mm is provided on each one side so that the part of a sent product enters the die assembly, a stepped part is generated on the product which is blanked out. By adopting the restrained half blanking stage and blanking-out stage, the blanking with the progressive press of the thin thickness parts is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production method capable of molding with less sagging and deformation even if the thickness is less than 80% of the plate thickness by press blanking, and more particularly to an upper mold and a lower mold of a mold. The present invention relates to a progressive press die in which a material is restrained and sealed to form a half-punched state, and a thin-walled article to be dropped in the next step is progressively punched.

[0002]

2. Description of the Related Art A conventional retainer has a wall thickness of 7 to a plate thickness.
Because of the shape that is easy to press and press, shaving was adopted and progressive press cutting was performed. However, since the thickness of the retainer this time was as small as 30% of the plate thickness, there was a drawback that dripping and deformation were increased even in shaving processing.

[0003]

[0007] Sharpening is used as a method of reducing the amount of sag because press sagging causes sagging. However, when the thickness is less than 80% of the plate thickness, deformation increases, Even if shaving processing is adopted, it is difficult to suppress sagging and deformation.

[0004] An object of the present invention is to solve the above-mentioned problems and suppress the sagging and deformation that occur during press punching by removing the entire material while restraining it in accordance with the shape of the upper die and the lower die. It is to provide a good progressive press die.

[0005]

The above object can be attained by cutting out the material to be fed progressively in the upper die and the lower die, sending it to the next step while keeping the material, and pulling it out.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A bit mounting portion of an electric impact wrench includes a retainer 1, a screwdriver 2, a slide spring 3, an anvil 4, a guide sleeve 5, and a steel ball 6.
And so on. The conventional retainer 8 has T1 of 1.9 mm, W1 of 1.3 mm, and the ratio of the wall thickness to the plate thickness is 7 mm.
Because of the splitting, the progressive press is performed by the shaving method of the processing layout 7.

In this case, the retainer 1 has T2 of 2.5 mm, W
2 is 0.8 mm, the ratio of the thickness to the plate thickness is 30%, and therefore, in the conventional method of the processing layout 7, the sag and the deformation are large like the retainer 9. Therefore, a constraint sequential removal of the processing layout 10 was developed. First, the work material 11 is pressed by the lower die 12 and the ejector 13 and the upper die stripper 14 by the spring pressure, and as the upper die is lowered, the hole of the work material 11 is formed by the mandrel 15 and the punch 16. Restrain. Since the work material 11 is all constrained, even if it is pulled out in that state, deformation and warpage are suppressed.

In the progressive feeding type, if the product is taken out in that state, the product cannot be taken out. Therefore, a 0.5 mm left unextracted portion is provided, a half-punched state is set, and the product is sent to the next step. In order to provide a gap of 0.02 mm on one side so that the product part sent into the mold at that time, C (0.02 mm)
Step occurs. By employing the restrained half-punching step and the drop-out step developed as described above, progressive press punching of thin-walled products becomes possible.

[0009]

According to the present invention, a thin-walled product having a thickness of up to 30% of the plate thickness can be pressed without sagging, and a progressive press die with higher productivity can be provided.

[Brief description of the drawings]

1A and 1B show the vicinity of a tool holding portion of an electric impact wrench having a retainer according to the present invention, wherein FIG. 1A is a longitudinal sectional side view partially omitted, and FIG. 1B is an enlarged view thereof.

FIG. 2 is an external view showing a retainer according to the present invention and a conventional retainer.

FIG. 3 is a progressive press working layout of a retainer according to the present invention and a conventional retainer.

FIG. 4 is a cross-sectional view showing a restraint release structure according to the present invention.

FIG. 5 is a processing layout for half-punching and dropping-out according to the present invention.

FIG. 6 shows a restrained progressive press-retainer shape according to the present invention.

[Explanation of symbols]

1 is retainer, 2 is Tomewa, 3 is slide spring,
4 is an anvil, 5 is a guide sleeve, 6 is a steel ball.

Claims (1)

[Claims] 1. A work material is pressed by a lower die and an ejector and an upper die by a spring pressure.
A step of restraining the hole of the material to be processed with a mandrel and a punch as the upper die is lowered, and further conveyed to the next step in a state where a product is attached to the material to be processed in a half-punched shape with the material being constrained, A progressive press punching method for thin-walled parts that includes a step of pulling out.