JPS6125393B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an inner cutter body of a reciprocating electric shaver.

Generally, in the inner cutter body of this type of electric shaver, when a plurality of inner cutter blades are fixed integrally with each other at a predetermined interval, a cylindrical pipe is inserted into the pipe insertion hole formed in each of the inner cutter blades. is inserted, and with each inner cutter blade positioned and held in this pipe, the diameter of the pipe is increased with a punching rod having a circular cross section, and each inner cutter blade is skewered into the pipe. It is customary to fix it to .

However, with this method, when the cylindrical pipe is expanded with a punching rod having a circular cross section, the outer circumferential surface of the pipe does not dig into the inner wall of the pipe insertion hole, and it is difficult to enlarge the diameter of the pipe with excessive force. It is difficult to firmly fix the inner cutter blade.

Therefore, in a cylindrical pipe 90 as shown in FIG.
Penetrate the punching rod 91 (FIG. 10) with a square cross section,
An attempt has been made to firmly fix each inner cutter blade 92 to the pipe 90 using the edge effect of the pipe 90, but in this case, conversely, stress is localized in the radial direction of the pipe 90. If the inner diameter of the pipe 90 and the outer diameter of the punching rod 91 are not strictly controlled, cracks P may occur in the pipe itself or the inner wall of the pipe insertion hole 93.

Therefore, this invention uses a rectangular pipe whose hollow part has a circular cross-sectional shape, expands this rectangular pipe with a punching rod having a circular cross-section, and fixes the inner cutter blade. To provide a method for manufacturing an inner cutter body of a reciprocating electric shaver, in which a pipe can be enlarged in diameter with a relatively small force, and each inner cutter blade can be firmly fixed.

An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 are a front view and a side view showing an example of the inner cutter body of a reciprocating electric shaver obtained by the manufacturing method of the present invention.
₁ , 1 ₂ ... 1 _o ) is a plurality of inner cutter blades, 2 is a pipe in which each of these inner cutter blades 1 is fixed in a skewer shape,
3 is a reinforcing plate.

Next, the manufacturing method of the above-mentioned inner blade body is shown in Figs. 3 to 8.
This will be explained with a diagram.

First, as shown in FIG. 3, a large number of semicircular inner cutter blades 1 are formed by punching or the like from a thin steel plate (not shown). A brass pipe to be inserted into a rectangular pipe insertion hole 4 is prepared. The pipe 2 is a rectangular pipe with a hollow portion 5 having a circular cross-sectional shape and an outer shape matching the pipe insertion hole.

Next, as shown in FIG. 4, the plurality of inner cutter blades 1
The rectangular pipe 2 is inserted into each pipe insertion hole 4, and the inner cutter blades 2 are positioned and held at a predetermined distance from each other.

Thereafter, as shown in FIG. 5, a punching rod 6 having a circular cross section slightly larger in diameter than the hollow part 5 is penetrated into the hollow part 5 of the square pipe 2 to enlarge the diameter of the pipe 2. Then, as shown in FIG. 6, each inner cutter blade 1 is integrally fixed to the square pipe 2 in a skewer shape.

Here, since the cross-sectional shape of the hollow part 5 of the square pipe 2 is circular, when the punching rod 6 is passed through the hollow part 5, the square pipe 2 in the state shown in FIG. , 2c, and 2d are deformed outward more than other parts, so each inner cutter blade 1 can be firmly fixed without greatly deforming the entire circumference of the square pipe 2. Moreover, since the stress is equally distributed and distributed on each side 2a to 2d, there is no fear of cracks occurring in the inner wall of the pipe insertion hole 4 of the inner cutter blade 1. By the way, it is also possible to expand the square pipe 2 with a punching rod having a square cross section, but in that case, the 11th
As shown in the figure, there are cases where the corner 100a of the punching rod 100 is located on the diagonal line of the square pipe 2, and in this case, the insertion pressure of the punching rod 100 becomes large and there is a risk that the punching rod 100 may be bent. However, since the punching rod 6 according to the present invention has a circular cross section, it can be easily inserted into the hollow portion 5 of the rectangular pipe 2 and can be penetrated with a relatively small insertion pressure.

As described above, according to the present invention, the pipe for fixing a plurality of inner cutter blades in a skewer shape is a rectangular pipe whose hollow section has a circular cross-sectional shape, and the rectangular pipe has a circular cross-sectional shape. Since the diameter is increased using a punching rod, each inner cutter blade is firmly fixed in a partially deformed part without having to forcefully increase the diameter of the entire square pipe, and it also prevents cracks in the inner cutter blade. It is possible to provide a method for manufacturing an inner cutter body of a reciprocating electric shaver that is free from the risk of.

[Brief explanation of the drawing]

1 and 2 are a front view and a side view showing an example of the inner cutter body of a reciprocating electric shaver obtained by the manufacturing method of the present invention, and FIG. 3 is an inner cutter blade used in the inner cutter body. Figures 4 to 6 are explanatory diagrams of the process for fixing the inner cutter blade of the same inner cutter body to the square pipe, and Figure 7 is the state before the square pipe is enlarged in diameter. Figure 8 is a cross-sectional view of a square pipe when the diameter is increased, Figures 9 and 10 are explanatory diagrams of the conventional example, and Figure 11 is a square pipe whose diameter is increased using a square punching rod. FIG. 1...Inner cutter blade, 2...Square pipe, 4...Pipe insertion hole, 5...Hollow part, 6...Drawing rod.

Claims (1)

[Claims] 1. When fixing a plurality of inner cutter blades 1 integrally with each other at a predetermined interval, the hollow portion 5 has a circular cross-sectional shape and is inserted into the pipe insertion hole 4 formed in the inner cutter blade 1. A certain rectangular pipe 2 is inserted, each inner cutter blade 1 is positioned and held in this pipe 2, and a punching rod 6 having a circular cross section is passed through the hollow part 5 to enlarge the diameter of the square pipe 2. A method for manufacturing the inner blade of a reciprocating electric razor.