JPS5913228B2 - Manufacturing method for electric razor outer blades - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an outer blade for a rotary electric shaver, which forms an annular rim around the back surface of a through hole.

In particular, when an annular rim is formed at the periphery of the back surface of a through-hole made by the etching method using an upper die and a lower die, and this outer cutter is squeezed into a curved surface, the rim that has been made at all costs is crushed. The present invention eliminates this problem.

・Hereinafter, one embodiment of the present invention will be described based on the drawings.
Figures 1 to 8 are process diagrams for the conventional method, and Figure 9
15 are process diagrams according to the present invention.

First, in the conventional process diagram, 1 is an outer cutter flat plate made of cutter steel such as stainless steel, and holes are formed in this outer cutter material 1 by etching.

Due to the nature of the hole created by the etching method, corrosion occurs straight from the top to the bottom of the material 1 (it does not form a hole), but as shown in the figure, the diameter of the hole 2 becomes narrower toward the bottom (it becomes a transparent hole 2). Become.

The inclination angle A of the through hole 2 is generally within 60 degrees.

Reference numeral 3 denotes a metal lower mold in which a number of recessed holes 4, 4, larger than the through-holes 2, are formed by the same etching method used to make the holes in the outer cutter flat plate 1; ... indicates that the inner wall surface 5 is an inclined surface, and the inclination angle B thereof is also about 60 degrees.

Reference numeral 6 denotes a metal upper mold having a large number of pressing protrusions 7, 7, . . . corresponding to the recessed holes 4, 4, .

Conventionally, as shown in the figure, the upper outer cutter material 1 is placed on the lower mold 3 with the narrowed side of the through hole 2 facing downward, and then the upper mold 6 is placed on its protruding parts 7, 7, . . .・Through hole 2.2...
If they are placed facing each other and pressed with a large pressure F, rims 8, 8, . . . are formed as shown in the figure.

However, these rims 8, 8... have an angle A as shown in the figure.
The rim has an acute angle.

Furthermore, as shown in FIGS. 5 and 6, if the pressing protrusions 7, 7 of the upper die 6 are displaced relative to the surface hole 2' of the outer cutter 1, one of the rims 8 that is pushed out will be defective. This results in a complete rim 8'.

In the case of the outer cutter flat plate 1 with the larger hole diameter facing upward, the pressing protrusions 7, 7... of the pressing mold 6 and the outer cutter flat plate 1
This is due to the small contact area with the

By the way, when the outer cutter flat plate 1 with the rims 8, 8... formed in this way is squeezed into a spherical shape with a pair of upper and lower drawing dies A and B as shown in Fig. 3, the rims 8, 8... Since the rims 8 and 8 have acute angles, there is a possibility that the rims 8, 8, . . . may be deformed.

When grinding this rim so that the rim has a sharp cutting edge of 60 degrees, the cutting edge will not have an acute angle (60 degrees) unless it is ground at least once. is an obtuse angle (120 degrees), resulting in poor cutting quality.

In other words, in the past, when drawing into a spherical shape, there is a risk that the painstakingly created rim 8. The work was difficult.

The present invention simply improves the above-mentioned drawbacks, and as shown in the figure, when placing the outer cutter flat plate 1 on the lower mold 3, it is placed with the narrow side of the through hole 2 upside down, unlike the conventional method. place

Thereafter, the rim 8 formed by pressing with the upper mold 6 becomes different from the conventional one in that its lower surface 9 is parallel to the outer cutter surface 10.

In addition, as shown in FIGS. 11 and 12, the pressing protrusions 7, 7 of the mold 6 and the through holes 2, 2, of the outer cutter 1 remain misaligned. Even if I press it, the rim is 8.8...
is almost completely extruded, and as in the past, both 6
, 1 does not require much attention.

Even if the outer cutter flat plate 1 with the rims 8, 8... made by the above-mentioned forming method is squeezed into a spherical shape, the rims 8, 8... are formed by the upper and lower drawing dies A, as shown in FIG. The spherical outer cutter 11 is not pressed and dipped by B, but remains in a complete shape.

Even if the rim 8 is ground, a sharp cutting edge 12, 12, etc. can be obtained with a small amount of grinding, and the outer cutter 11 with good cutting quality can be manufactured without difficulty.

In short, it is okay even if there is a slight difference in the amount of grinding, so grinding does not require as much labor as in the past.

As described above, the outer cutter flat plate with the hole drilled using the etching method is formed with a female lower die and male upper die to form an annular rim around the hole, and the outer cutter flat plate with this rim is squeezed into a spherical shape. When using conventional rim forming methods, the painstakingly created rim may be crushed, and the rim, which was designed to reduce contact resistance with the inner cutter and improve sharpness, no longer performs its function. Also, when performing a cutting process to form a rim with a sharp edge from a rim that was not so immersed, there was a drawback that a considerable amount of cutting had to be performed, but the present invention solves this problem. When a hole is made by etching, the hole is not the same size on both sides of the outer cutter plate, and is always narrower on one side.

That is, the through hole has an inclined inner wall surface.

Conventionally, when this outer blade material was placed on the lower die, the narrower side of the through hole was placed down and the rim was extruded and molded by the upper die.However, the present invention does this. On the contrary, if you place the rim on the lower mold with the narrow side facing upward and push out the rim, the lower surface of the resulting rim will be parallel to the outer blade surface, and even if you squeeze the outer blade, The spherical surface of the drawing die and the lower surface of the rim are in uniform plane contact, and the rim is pressed;
There is nothing to be done.

Therefore, the spherical outer cutter after drawing becomes an outer cutter with a rim that maintains a perfect shape, and an outer cutter with low contact resistance with the inner cutter and good cutting quality can be expected.

Furthermore, when finishing grinding the rim to create a perfect edge, that is, a sharp cutting edge that is advantageous for sharpness, it is possible to form a sharp edge with a small degree of grinding, which has a unique effect not found in conventional methods. has.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS. 1 to 4 are diagrams of the rim forming and drawing process in the conventional normal method, and FIGS. 5 to 8 are the same (conventional method). 9 to 15 are diagrams of the process of forming and squeezing the rim in the case of abnormal conditions, and are diagrams of the process of forming and squeezing the spring according to the method of the present invention. 2, 2...Through hole, 4, 4...Concave hole, 3...Lower mold, 8.8...Annular rim, 9・・・・・・ Flat surface.

Claims (1)

[Claims] 1. Rub the outer cutter flat plate with a large number of through holes in it by the etching method, with the side with the larger hole facing downwards, and place the recesses on the surface of the lower die, which also has a large number of recessed holes formed in the same manner by the etching method. The lower end surface of the annular rim pushed out to the periphery of the back surface of the through hole 9 by a press is made a flat surface parallel to the surface of the outer blade, and the outer blade is equipped with the rim. A method for producing an outer blade for an electric shaver, in which the curved surface of the lower drawing die is brought into full contact with the lower end surface of the rim during drawing into a spherical shape of a flat plate.