JPH0550310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an inner cutter for an electric shaver using a ceramic cutter.

(Prior Art) An electric shaver, particularly a round-shaped inner cutter, is provided with a plurality of blade portions at predetermined intervals in the circumferential direction on the periphery of a round-shaped body to be rotated.

FIG. 12 to FIG. 15 show a conventional method for manufacturing an inner cutter, and the explanation will be added below. Figure 12~
FIG. 14 shows the inner cutter blank manufactured by each process, and A in the figure is a plan view of the inner cutter blank, and B in the figure is a front view of one blade forming part. Also, the first
FIG. 5 is a side view of one blade forming part.

First, a flat inner cutter blank 50 shown in FIG. 12 is punched out of a plate material (not shown). The inner cutter blank 50 is composed of a disk portion 51 and a large number of blade forming portions 52 provided radially from the periphery of the disk portion 51.

Next, the tip half portion 52 of the blade forming portion 52
As shown in Fig. 13B, bend a to one side using a press along a tangent line R1 inclined to the radial direction.
The bending angle is close to 90°. Also, at this time, the disk portion 5
The discharge holes 53 in 1 are also drilled. After this, the vicinity of the root side of the blade forming part 52 in FIG.
As shown in Figure B, the other side (half part 52a
(on the opposite side) and then heat-treated to have a hardness of about 650 degrees (Vickers hardness).

Then, as shown in FIG. 15, the blade forming portion 52 (FIG. 14B) is polished so as to be sliced along the horizontal line R2, a sharp edge is applied, and a flattening process is performed at the same time. Blade part 5
4 (see Figure 11).

After this, the inner side (center side) 54a and outer side 54b of the blade part 54 are polished and finished in order to make the outer diameter Do and the inner diameter Di (Fig. 11) formed by each blade part 54 into a perfect circle. The inner cutter 60 is formed by this.

Most of the conventional inner cutters adopt such a manufacturing method, and for example, inner cutters manufactured are known from Japanese Patent Application Laid-Open No. 54-81956, Design No. 566625, etc.

(Problems to be Solved by the Invention) However, such conventional inner cutters have the following problems.

First, it is impossible to use ceramic blades, which have characteristics such as long life, high hardness, and no rust, which have recently attracted attention as a material for cutting blades. In other words,
There are many bending processes, etc., and the shape of this type of inner cutter is complex and small, making the processing structure difficult, making it virtually impossible to use ceramic blades as inner cutters for electric shavers. This is the reality.

Secondly, the conventional inner cutter has many common inner cutter manufacturing problems in the following points.

(1) If the so-called progressive press method is adopted to reduce costs, there will be a large number of unnecessary parts in the material, increasing the material cost. Material becomes difficult. Furthermore, when the number of blades increases, the spacing between the blade forming portions 52 in the inner cutter blank 50 becomes narrower, resulting in a thinner part of the mold, which significantly shortens the life of the mold.

(2) The bending process using a press is required at least twice, which causes variations in the formation position of each blade portion 54 due to spring back of the material.
In addition, since heat treatment is performed after the complicated bending process using a press, different heat treatment strains occur in each blade part 54, and different strains also occur in the roll direction. can't get it.

(3) Since there are variations in the formation position of each blade part 54 and variations in the height of each formation part 52 due to heat treatment distortion, it takes a lot of polishing allowance ( Fig. 15 52b) needs to be ground. Further, as is clear from the plan view of one blade forming portion 52 shown in FIG. 11, the inner blade 6 formed by the blade portion 54 in the same figure
Since the inner diameter Di and outer diameter Do of 0 are not perfectly circular,
A polishing step is required to align each blade portion 54. Moreover, since there are spaces between each blade part 54 and each blade part 54 has been heat-treated and has become brittle, a lot of time is wasted in the polishing process.

(4) Although the blade forming portion 52 is bent by a press, there are some unreasonable bends, which weakens the mechanical strength. This causes problems such as easy breakage.

(5) As is clear from FIG. 11, since the tip of the half portion 52a of the blade forming portion having a relatively wide area is ground to form the blade portion 54, shaved beard, skin oil, etc. are removed from the half portion 52a. A large amount adheres to the back side.
For this reason, it is difficult to remove, making cleaning difficult.

The present invention provides an inner cutter for an electric shaver that eliminates all such problems.

(Means for Solving the Problems) The present invention has the following configuration in order to solve the above problems.

That is, in the inner cutter for an electric shaver, which has a plurality of cutting parts arranged at predetermined intervals in the circumferential direction on the periphery of a round rotated body, the bowl has a cylindrical part extending a predetermined length in the axial direction from the periphery of the disc part. The base has a shaped base, an extending part is formed on the periphery of the base that projects in the axial direction, and the tip of the extending part is made into a flat surface, and a flat ceramic blade is fixed to the flat surface so that the front end in the rotational direction A blade portion is formed at the front end in the rotational direction, and a gap between each adjacent extension portion of the extension portions is formed into a blade groove whose front face shape is U-shaped. shall be.

(Example) Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

First, the manufacturing method most suitable for obtaining the inner cutter according to the present invention will be sequentially explained for each step with reference to FIGS. 3 to 8. Figures 3 to 5, Figures 7 and 8
The drawings show an inner cutter blank manufactured by each process, and FIG. 6 shows a ceramic plate. In each drawing, A is a front half-sectional view and B is a bottom view.

[Mold cutting process]

First, in a die-cutting process, a bowl-shaped inner cutter blank 10 shown in FIG. 3 is punched out from a plate material (not shown).
The inner cutter blank 10 includes a disk portion 10a and a cylindrical portion 10b extending a predetermined length in the axial direction from the periphery of the disk portion 10a. In this die-cutting process, the attachment hole 20 and the discharge hole 21 to be bored at the center of the disk portion 10a and around the center are also punched out at the same time.

[Drawing process]

Next, as shown in FIG. 4, the cylindrical portion 10b of the blank 10 is squeezed with a press to form a small cylindrical portion 12 having a reduced diameter, and at the same time, a flange-shaped ring is bent radially outward from the periphery of the opening end. Plate part 13
form. The width L1 of this ring plate portion 13 is the width of the blade portion 5. Therefore, the width of the blade portion 5 can be selected depending on the diameter of the cylindrical portion 10b that is reduced by the aperture.

[Second drawing process] Next, the small cylinder part 1 squeezed in the above drawing process
As shown in FIG. 5, the disk portion 10a side is further narrowed down from a predetermined intermediate position in the axial direction to make the diameter smaller.
A second small cylinder portion 22 is formed. Note that this second squeezing step may be omitted and the second small cylinder portion 22 may not be particularly provided, but by providing it, the shaved beard can be discharged downward more smoothly.

[Ceramic board adhesion process]

On the other hand, a ring-shaped ceramic plate 7 shown in FIG.
Prepare. The thickness of this ceramic plate 7 is 0.2mm
The outer diameter and inner diameter of the ring are made to match the outer diameter and inner diameter of the ring plate portion 13, respectively.

Then, as shown in FIG. 7, the ceramic plate 7 is bonded to the plate surface 14 of the ring plate portion 13 with an adhesive.

[Blade cutting process]

As shown in FIG. 8, the inner cutter blank 10 that has undergone the polishing process is formed with blade grooves 15 using a grinding tool 23 such as a rotary whetstone (for example, a diamond whetstone) that is disc-shaped and has a rounded circumference. do. This blade groove 1
5 is a ring plate portion 13 from the plate surface of the ceramic plate 7;
Furthermore, it is formed in the shape of a notch in the small cylinder part 12, and the blade groove 15 cuts into the boundary between the small cylinder part 12 and the second small cylinder part 22. The blade groove 15 (grinding tool 23) is inclined at a predetermined angle in the direction of rotation of the inner cutter, and as shown in FIG. 6, the optimum angle of inclination θ1 is about 25° to 35°.
Further, the blade groove 15 (grinding tool 23) is slightly inclined with respect to the radial direction. This inclination angle θ2 creates an intersecting angle with respect to the outer cutter as shown in FIG. 1, and is optimally approximately 12°.

By caulking and attaching the engaging member 31 that engages with a drive pole (not shown) to the attachment hole 20 of the inner cutter main body 30 processed through the above steps, the inner cutter 1 shown in FIGS. 1 and 2 can be assembled. Complete.

Next, the inner cutter 1 manufactured by such a manufacturing method will be explained with reference to FIGS. 1, 2, 9, and 10. Fig. 1 is a plan view of the inner cutter for an electric shaver according to the present invention, Fig. 2 is a front half-sectional view of the inner cutter, Fig. 9 is a plan view showing one blade part of the inner cutter, and Fig. 10. is a front view showing the same blade part.

The inner cutter 1 includes the disk portion 10a and the disk portion 10a.
A bowl-shaped base 10c is provided with a cylindrical portion 10b extending a predetermined length in the axial direction from the periphery of the base 10c, and a plurality of extending portions 4 protruding in the axial direction are integrally formed on the periphery of the base 10c. The extending portion 4 extends from near the end of the second small cylinder portion 22 at an angle in the direction of rotation, and
Each of the extending portions 4 has a chevron shape that becomes narrower on the tip side, and between each of the extending portions 4 there is a blade groove 15 having a U-shaped front surface. Moreover, the extension part 4 is
It extends outward in a stepped manner.

The extending portion 4 integrally has a horizontal portion 9 projecting outward in the radial direction at the tip thereof, and a ceramic blade 6 is integrally stacked on the upper surface of the horizontal portion 9. This ceramic blade 6 has a blade portion 5 at the front end in the direction of rotation.

The cross section of the horizontal portion 9 and the ceramic blade 6 perpendicular to the longitudinal direction forms a substantially parallelogram as shown in FIGS. 2 and 10, and the planar shape thereof forms a substantially trapezoid as shown in FIG. Although the embodiments have been described in detail above, the present invention is not limited to these embodiments. For example, the second drawing step may not be necessary,
Further, in addition to the second drawing step, a third drawing step may be provided in which each extension portion 4 is of a two-step type. In addition, selection of the size of angles θ1 and θ2, L1
The selection of the size is arbitrary.

Furthermore, in the present invention, individual ceramic blades 6 as shown in FIG. 10 may be formed in advance and such individual ceramic blades 6 may be bonded to the flat end surface 3 of the extending portion 4. Further, although this is applied to the inner cutter, the outer cutter may be constructed by, for example, adhering the ceramic plate 7 to the back surface of the outer cutter and drilling it.
It can be similarly applied and configured to reciprocating type inner and outer cutters.
Furthermore, arbitrary changes in the shape, structure, quantity, size, etc. of details are permitted within the scope of the present invention without departing from the gist of the present invention.

(Effects of the Invention) Since the present invention is configured as described above, it has the following effects.

First, ceramic blades, which are excellent materials for cutting blades, can be used, and moreover, they are extremely easy to manufacture and process. Therefore, it has many of the properties that ceramic blades have, such as excellent sharpness due to high hardness, long life, and no rust.

Second, in addition to the first effect described above, there are many effects as described below from the viewpoint of general inner cutters such as shape.

The blade portion of the inner cutter according to the present invention shown in FIG.
As is clear from the comparison of the blade portion of the inner cutter according to the conventional example shown in FIG. Therefore, shaving hair and skin oil are less likely to adhere to the blade portion and the horizontal portion.

In addition, the space between each extension part is a blade groove with a U-shaped front face, and the front face of each extension part is a mountain shape, and the space between each extension part is wide, making it easy to cut. Even long whiskers, etc., are discharged downward from the blade groove. Therefore, cleaning of the inner cutter becomes extremely easy.

By making the horizontal part protrude outward compared to the extended part, and by extending the extended part in a step-like manner, a blade groove is also created below the blade part of the horizontal part, as shown in Figure 9. Since there is no such thing, cut beards, etc. are smoothly discharged downward as they are. Furthermore, even long whiskers, etc., do not stay in the blade grooves and are ejected as they are.

Because the base is formed into a bowl shape, there is a cylindrical part on the outside, so the weight distribution is biased to the outside compared to the conventional one, and the inertia force increases, resulting in considerable fluctuations in rotational speed due to temporary loads and stability. performance.

Since the extension part stands up from the periphery of the cylindrical part existing on the outside of the base, the length of the extension part can be shortened, and there is no need to bend it at the base side as in the conventional case. Therefore, the strength can be increased, and stable performance can be maintained even under the above-mentioned loads.

[Brief explanation of drawings]

FIG. 1 is a plan view of the inner cutter for an electric shaver according to the present invention, FIG. 2 is a front half-cut sectional view of the inner cutter, and FIG.
5, 7 and 8 show an inner cutter blank manufactured by each process for producing an inner cutter for an electric shaver according to the present invention, and FIG. 6 shows a ceramic plate, and FIG. A in the figure is a front half-cut sectional view, B in the figure is a bottom view, Fig. 9 is a plan view showing one blade part of the same inner blade, Fig. 10 is a front view of the same blade part, and Fig. 11 is a conventional example. FIGS. 12 to 14 are plan views showing one blade portion of such an inner cutter for an electric shaver, and FIGS. 12 to 14 show an inner cutter blank manufactured by each process of a conventional method for manufacturing an inner cutter for an electric shaver. In the figure, A is a plan view of the inner cutter blank, B in the figure is a front view of one blade forming part, and FIG. 15 is a side view of one blade forming part in the same inner cutter blank. In the drawing, 1... inner blade for electric shaver, 2...
Round rotated body, 3...Flat surface, 4...Extended portion, 5
...Blade part, 6... Ceramic blade, 7... Ceramic plate.

Claims (1)

[Scope of Claims] 1. An inner cutter for an electric shaver comprising a plurality of blades at predetermined intervals in the circumferential direction on the periphery of a round rotated body, in which the cylindrical part extends a predetermined length in the axial direction from the periphery of the disc part. It has a bowl-shaped base that extends out, an extension that projects in the axial direction is formed on the periphery of the base, the tip of the extension has a flat surface, and a flat ceramic blade is fixed to the flat surface. An electric shaver characterized in that a blade portion is formed at the front end in the rotational direction, and a gap between adjacent extension portions of the extension portions is formed as a blade groove having a U-shape in front. Inner blade.