JPS5944290A - Production of inner blade of rotary electric razor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an inner cutter for a rotary electric shaver in which a plurality of helical inner cutter plates are integrally formed on the circumferential surface of a tubular rotating body.

If the inner blade of a low-cut electric shaver is formed into a helical shape, it will rotate quietly with very little chatter, have good sharpness, and have the advantage of eliminating the fall of the outer blade. be.

Methods for integrally forming a helical inner cutter plate with such advantages on the circumferential surface of the rotating body include a method of first cutting the circumferential surface of a tubular or rod-shaped material with a rotating grindstone;
There are two possible methods of obtaining the material, including rolling, but these methods do not allow for mass production and have low productivity. Next, as a method to enable mass production, an inner cutter having a helical inner cutter blade is extruded onto the circumferential surface of the tubular rotating body by extrusion processing, that is, extruding the material billet through a die. There are possible ways. According to this extrusion processing method, the material is extruded into a tubular body with a predetermined cross-sectional shape and twisted at the same time, but this extruded tubular body that becomes the inner cutter is thin, and in addition, it is difficult to extrude. If twisting is applied when opening, defects such as cavities and cracks are likely to occur. this is.

The heat generated by deformation and frictional work does not have time to escape, and the extrusion and twisting processes continuously generate heat, so the temperature rises rapidly. For this reason, materials that exhibit high-temperature brittleness, especially materials with structures with low melting points such as strong aluminum alloys, are prone to cracking on the surface, and the surface layer, which is severely deformed, tends to coarsen grains and reduce strength. It is in.

Focusing on this fact, the present invention provides an extrusion molding process in which the rotating body of the inner cutter and the inner cutter blade are integrally extruded;
The process of attaching the lead to the inner cutter plate is performed separately.
The object of the present invention is to provide a method for manufacturing an inner cutter for a low-cut electric shaver, which can mass-produce high-quality inner cutters free from defects such as cracks.

The details will be explained below based on the drawings.

FIG. 1 shows an example of the head portion of a rotary electric razor, which is placed on the top of the main body case 1.

A mesh outer cutter 2 stretched in a semicircular shape is removably attached to an outer cutter boulder 3, and a plurality of helical inner blades are provided on the circumferential surface of the tubular rotating body 4 at a constant angle with respect to the body axis. An inner cutter 6 integrally formed with the cutter plate 5 is installed so as to be able to slide and rotate against the inner surface of the outer cutter 2. Inner blade 6 is 1
A gear 8 is fixed to one end of the shaft 7 of the morph 9, and the drive gear 11 of the morph 9 built in the main body case 1 is transmitted to the gear 8 through a group of 12 reduction gears.
rotate around.

The inner cutter 6 is manufactured as follows. first.

As shown in FIG.
14. The billet 13 is pressurized by the ram 15 and extruded from an outlet between the inner die 16 and the outer die 17. Inner and outer dice 16.1
The shape of the “I” formed between 7 and 7 is as shown in Figure 4,
An annular hole 18 and a plurality of (six grooves in the illustrated example) outward grooves 19 that protrude radially outward from several locations on the outer periphery of the hole 18. and inward grooves 20 (two grooves in the illustrated example) projecting radially inward from several locations on the inner periphery of the hole 19. Therefore, during extrusion, the billet 13 is passed through the inner and outer dies 16.
・A tubular body 23 having fin-like pieces 21 and 22 parallel to the tube axis direction on the inner and outer circumferences as shown in FIG. It becomes extruded.

The tubular body 23 is extruded into such a cross-sectional shape.

The rod 25 is inserted into a die mold 24 for attaching a lead as shown in FIG. Insert it so that it fits and becomes a lock.

This causes the tubular body 23 to be pushed out below the die 24 while being twisted. The hole of the die mold 24 has a shape as shown in FIG. 6, and has a plurality of helical grooves 26 on the inner periphery that are inclined at a constant angle with respect to the axial direction.

Each helical groove 26 is formed into a fin-like piece 2 when the tubular body 23 is inserted.
In order to facilitate insertion of the helical groove 26 into the helical groove 26, the end 26a on the inlet side thereof is formed into a straight line parallel to the axial direction.

During extrusion, the tubular body 23 is twisted and extruded with a lead attached to the fin-like pieces 22.

Finally, the tips of the fin-shaped pieces 22 are alumite-treated, and then the centerless blades are sharpened by grinding them on a grindstone. In this way, an inner cutter 6 is obtained in which the tubular body 23 becomes the rotary body 4 and the fin-like pieces 22 serve as the helical inner cutter plate 5.

As explained above, according to the manufacturing method of the present invention, the inner cutter 6 having the helical inner cutter blade 5 on the circumferential surface of the two-turn barrel 4 can be mass-produced.

In particular, in this invention, first, the tubular body 2 that becomes the rotating body 4 is
3 and a fin-like piece 22 parallel to the tube axis direction that becomes the helical inner blade 5 on the circumferential surface thereof is integrally extruded.The fin-like piece 22 is then formed in a separate primary process. Since the tubular body 23 having the structure is passed through the die mold 24 and a lead is attached to the fin-like piece 22, the inner blade 5 acts as a cooling fin during the manufacturing process, preventing deformation due to heat and crystal grains. Since the lead is attached after the material itself has been stabilized to prevent a decrease in strength due to coarsening, it is possible to obtain a high-quality inner blade for a rotary electric shaver without defects such as cavities or cracks.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a rotary electric shaver, Fig. 2 is a perspective view of the inner cutter, Fig. 3 is a sectional view of a billet being extruded through a die, and Fig. 4 is a cross-sectional view of the inner cutter. 3 is a sectional view taken along the line IV-TV in FIG. 3, FIG. 5 is a perspective view of the extruded tubular body, and FIG. 6 is the tubular body in a state before attaching a rotating push rod and a lead. FIG. 2 is a perspective view showing a die type for use with a lead, and a tubular body, that is, an inner cutter after cutting-1. 4...Rotating body. 5... Inner blade. 6... Inner blade. 13. . . . Billet. 14...Container. 15...Rum. 16...Inner dice. 17... Outer dice. 22...Hilary piece. 23...Tubular body. 24... Dice type. 26...Helical groove. Patent applicant: General Hitachi Maxell) Unregistered company agent: Takeshi Oriyose, patent attorney: Figure 1 Figure 2

Claims (1)

[Claims] (1) When manufacturing the inner cutter 6, which is formed by integrally forming a plurality of helical inner cutter blades 5 that are inclined at a constant angle with respect to the barrel axis on the circumferential surface of the tubular rotating barrel 4, heat is applied. By extrusion processing, the tubular body 23 that will become the rotating body 4 of the inner cutter 6 is extruded, and at the same time, the fin-like pieces 22 that will become the inner cutter plate 5 of the inner cutter are formed on the circumferential surface of the tubular body 23 in the tube axis direction. The tubular body 23 having the fin-like pieces 22 is formed integrally in parallel with each other.
One fin-shaped piece 22 is inserted into a die mold 24 having a plurality of helical grooves 26 inclined at a constant angle with respect to the axial direction on the inner periphery so as to follow the inside of the helical groove 26, and twisted while pushing to form the fin-shaped piece 22. A method for manufacturing an inner blade of a rotary electric shaver, characterized in that the inner blade of the rotary electric razor is cut by 1°.