JPS5913227B2 - Manufacturing method for the inner blade of a rotary electric shaver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In a rotary electric shaver, the present invention reduces the contact resistance by thinning the cutting edge of the inner cutter and reducing the area of the inner cutter edge surface in contact with the back surface of the outer cutter. The present invention also relates to a method of manufacturing an inner cutter that has a sharp cutting edge that ensures sharp contact with the back surface of the outer cutter, thereby improving the sharpness of the cutting edge.

Hereinafter, one embodiment of the present invention will be described based on the drawings.
Guide holes 2, 2, . . . are bored at equal pitches P in a strip-shaped inner blade material 1 of a rotary electric shaver shown in FIG. 1 using a press.

As shown in FIG. 2, a resist 3 is uniformly applied to both surfaces of the inner cutter material 1 with holes formed therein. Next, as shown in FIG. 3, the parts where the plate thickness is to be reduced are opaque parts 4, 4..., the guide holes 5, 5... for alignment, and the other parts are transparent parts 6, 6.
...A pattern (film) 7 is prepared. The pitch P of the guide holes in this pattern 7 is the same as the pitch P of the guide holes in the inner cutter material 1. As shown in FIG. 4, this pattern T is exposed by aligning guide holes 5, 5, . . . with guide holes 5, 5, . If the phenomenon occurs after exposure, as shown in Fig. 5, the metal parts will be exposed in the parts 8, 8, where the plate thickness is to be made thinner, and the other parts 9, 9, etc. will be covered with the resist 3, that is, the insulating film. coated. The inner cutter material 1 with the pattern baked thereon is continuously passed through an etching liquid tank 11 filled with a chemical polishing liquid 10 via rolls 12, 12, . . . in the manner shown in FIG. Here, the following composition of the etching solution is suitable. That is, it is a mixed liquid of (COOH)2, H202, and fluoride water. Then, by adjusting the time for the inner blade material 1 to pass through the etching liquid tank 11, the metal exposed portion 8 shown in FIG. 5 has a material thickness of 0.12U to 0.15wt.
This is 0.07″5~0.08tngt as shown in Figure 7.
Perform the etching operation until it becomes . As a result, the portions 9, 9, . . . covered with the resist 3 are not etched, and the original material thickness is maintained as it is. After etching in the manner described above, the resist 3 is peeled off, and the inner cutter is pressed using a mold in the process shown in FIG. A progressive mold is used as the mold, and the guide holes 2, 2, . . . are guided by pilot pins to feed the material exactly by the pitch P in each step. Here, 12 is a hole for the inner blade push-up spring, 13 is a notch on the side surface, 14 is a notch on the radiused part of the cutting edge, 15, 1
6 is an end notch and a cutting edge bending process. More bending line 1? is located at the left side of the boundary line 18 between the thicker and thinner parts, that is, the thicker part. If the above-mentioned processing is performed, the single inner cutter 19 will have a shape as shown in FIG. 90 after press processing, and the cutting edge portion 2
Only the part 0 is thin, and the other part, that is, the inner blade base 21, has the same material thickness and is thicker than the cutting edge part. Therefore, this inner blade 1
9, the blade surface 2 of the cutting edge becomes the first one as shown in Figure 10.
It is thinner than the cutting edge surface 22 of the inner cutter 19'35 with the same material thickness as shown in FIG. 1, and the cutting edge is also sharp. If you just want to make the same thickness thinner, the thickness of the material should be 0.07 as shown in Figure 12.
Although the same effect can be expected in terms of performance with the inner cutter 19' made as thin as 1.1 mm, it has problems in terms of strength and cannot be put to practical use.

Therefore, the proposed inner blade is better. As described above, the present invention provides an inner cutter material with a part other than the part that becomes the cutting edge of the inner cutter.
That is, the part that will become the base of the inner cutter is sequentially coated with an insulating film, the inner cutter material treated in this way is passed through an etching solution, and then cut to a fixed size to form an inner cutter with the cutting edge being thinner than the base. Since a large number of blade pieces can be manufactured, since the cutting edge is thin, the surface where the cutting edge comes into contact with the outer blade is naturally reduced, reducing contact resistance and achieving sharp cutting.

In addition, the base of the inner cutter maintains the same thickness of the material as before, so it is strong enough. In addition, it is possible to automatically produce a large number of inner blades in a short time simply by passing them through an etching solution and cutting them one after another, making it suitable for mass production and reducing overall manufacturing costs. It is possible to provide a method for manufacturing inner blades in a rotary electric shaver that has industrial value.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view and a side view of a strip-shaped inner blade material, FIG. 2 is a diagram showing a state in which resist is applied to both sides of the inner blade material, and FIG. 3 is a diagram showing the resist applied to both sides of the inner blade material. Figure 4 is a diagram of the film pattern stretched over the resist, Figure 5 is a diagram of the film pattern stretched over the resist, Figure 5 is a diagram of the film pattern removed after exposure and development, and Figure 6 is the inner blade material. Figure 7 shows the process of passing through the etching solution,
A cross-sectional view and a plan view of the inner cutter material with the exposed surface of the material etched, FIG. 8 is a diagram showing the condition of punching out a small inner cutter piece from the inner cutter material, and FIG. 9 is a front view and a cross-sectional view of the punched inner cutter piece. , Fig. 10 is a cross-sectional view of the main guide blade when the inner cutting edge has been polished for final finishing, and Fig. 11
The figure is a sectional view of the inner blade in which both the cutting edge and the inner blade base have the same thickness as the material, and FIG. 12 is a sectional view of the inner blade in which both the cutting edge and the inner blade base are thinned to a constant thickness from the material thickness. 1... Band-shaped material, 3... Insulating film, 10
... Etching liquid.

Claims (1)

[Claims] 1. The strip-shaped material is coated with an insulating film on both sides so that the base of the inner cutter is covered with an insulating film, and the part that will become the cutting edge is coated with an exposed surface of the material. After passing the strip-shaped material into the etching solution, a large number of A method for manufacturing an inner blade of a rotary electric shaver by cutting the inner blade into small pieces.