JPH0550309B2 - - Google Patents

Description

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

(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 disc-shaped rotating body.

FIGS. 9 to 12 show a conventional method for manufacturing an inner cutter, and a description thereof will be added below. Figure 9-1
Fig. 1 shows the inner cutter blank manufactured by each process, 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. Moreover, FIG. 12 is a side view of one blade forming part.

First, a flat inner cutter blank 50 shown in FIG. 9 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. 10B, bend a to one side using a press along a tangent 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. 12, if the blade forming part 52 (FIG. 11B) is polished so as to be sliced along the horizontal line R2, a sharp edge is applied, and a plane processing is performed at the same time, the tip of the blade forming part 52 is Blade part 5
4 (see Figure 8).

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. 8) formed by each blade part 54 into a perfect circle. The inner cutter 60 is formed by this.

In this way, most of the conventional inner cutters adopt the above-mentioned manufacturing method, and their shape is as shown in Figure 8. Are known.

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

First, adopted to reduce costs,
According to the so-called progressive press method, there are many unnecessary parts in the material, which increases the material cost, and the blade forming portions 52 engage with each other, making automatic material feeding by a parts feeder or the like 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.

Second, the bending process by press is at least two
This causes variations in the formation position of each blade portion 54 due to the 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.

Thirdly, because 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 to make all the blade surfaces flat in the same plane. (Fig. 12 52b) needs to be ground. Further, as is clear from the plan view of one blade forming portion 52 shown in FIG. 8, the inner diameter of the inner cutter 60 formed by the blade portion 54 in the same figure
Since Di and external shape Do are not perfectly circular, each blade part 5
A polishing process is required to align 4. 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.

Fourthly, although the blade forming portion 52 is bent by a press, there are some unreasonable bending points.
Mechanical strength becomes weaker. This causes problems such as easy breakage.

Fifth, as is clear from FIG. 8, 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 of the 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. A base having a shape, a longitudinally extending portion protruding in the axial direction is formed on the periphery of the base, and a horizontally extending portion protruding in the radial direction is integrally formed at the tip of the longitudinally extending portion, and the horizontally extending portion is integrally formed at the tip of the longitudinally extending portion. A blade part is formed at the front end in the rotational direction of the extending part, and a blade part is formed between each adjacent longitudinally extending part of the longitudinally extending part.
is characterized in that each front face shape is formed in a U-shaped blade groove.

Further, the longitudinally extending portion may be formed to be inclined toward the rotation direction, and the longitudinally extending portion may be formed in a stepped shape toward the outside. Furthermore, the horizontally extending portion may protrude outward in the radial direction with respect to the longitudinally extending portion.

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

First, in order to facilitate understanding of the inner cutter 1 according to the present invention, a method for manufacturing the inner cutter 1 will be sequentially explained for each step with reference to FIGS. 3 to 6. Each figure A and B shows the inner cutter blank manufactured by each process, A is a front half-cut 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 2 and a cylindrical portion 11 extending a predetermined length from the periphery of the disk portion 2 in the axial direction. In this die-cutting step, the center of the disk portion 2 and the attachment hole 20 and the discharge hole 21 to be bored around the center are also punched out at the same time.

[Drawing process]

Next, as shown in FIG. 4, the cylindrical portion 11 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. A plate portion 13 is formed. The width L1 of this ring plate portion 13 is the width of the blade portion 7.
The width will be . Therefore, the width of the blade portion 7 can be selected depending on the diameter of the cylindrical portion 11 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.
A 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.

[Heat treatment process]

Next, heat treatment (quenching) is performed to harden the inner cutter blank 10. The hardness should be approximately 650 degrees in terms of Bitskars hardness.

[Polishing process]

The plate surface 14 of the ring plate portion 13 of the inner cutter blank 10 that has been heat-treated is polished. Through this treatment, the plate surface 14 is finished to a flat surface and becomes a completely flat surface.

[Blade cutting process]

As shown in FIG. 6, 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 or a cutter, which is disc-shaped and has a rounded circumferential surface. This blade groove 15 is formed in a notch shape from the ring plate part 13 to the small cylinder part 12, and this blade groove 15 cuts to the boundary between the small cylinder part 12 and the second small cylinder part 22. Note that, although this cutting depth is optimal, it is not limited to this, and may reach the disk portion 2, for example. 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, this inclination angle θ1 is 25°.
~35° is optimal. 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 according to the present invention manufactured by such a manufacturing method is shown in FIGS.
This will be explained with reference to the figures. FIG. 1 is a plan view of an inner cutter for an electric shaver according to the present invention, FIG. 2 is a front half-sectional view of the inner cutter, and FIG. 7 is a plan view showing one blade portion of the inner cutter.

The inner cutter 1 includes the disk portion 2 and the peripheral edge 2 of the disk portion 2.
It is provided with a bowl-shaped base 4 which extends a cylindrical part 3 a predetermined length in the axial direction from a, and a plurality of vertically extending parts 5 projecting in the axial direction on the periphery of the base 4 are integrally formed. These longitudinally extending portions 5 extend from near the end of the second small cylinder portion 22 at an angle in the rotational direction, and each longitudinally extending portion 5...
The blades have a chevron shape that becomes narrower at the tip end, and between the longitudinally extending portions 5 there are blade grooves 15 each having a U-shaped front surface. Further, the longitudinally extending portion 5 protrudes outward in a stepped manner.

The longitudinally extending portions 5 integrally have a horizontally extending portion 6 protruding outward in the radial direction at the distal end thereof, and the horizontally extending portion 6 has a blade portion 7 at its front end in the rotational direction.

The vertical cross section of the transversely extending portion 6 in the longitudinal direction is the second
As shown in the figure, the shape is approximately a parallelogram, and the planar shape is approximately trapezoidal as shown in FIG. The outer thickness L2 of the horizontally extending portion 6 formed in this manner substantially matches the thickness of the forming material.

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 be omitted, or in addition to the second drawing step, a third drawing step may be provided in which each longitudinally extending portion 5 is made into a two-stage stepped structure.
Also, selection of the sizes of angles θ1 and θ2, L1, L
The selection of the size of 2 is arbitrary. Further, 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.

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 the figure, the blade portion of the inner cutter according to the present invention is formed into a horizontally extending portion that protrudes outward and has a relatively small front surface area. Therefore, shaved hair and skin oil are less likely to adhere to the blade portion and the horizontally extending portion.

In addition, the space between each longitudinally extending portion is a blade groove whose front shape is U-shaped, and the front face of each longitudinally extending portion is a mountain shape, and the space between each longitudinally extending portion is wide. Therefore, cut whiskers, etc., even if they are long, are smoothly discharged downward from the blade groove. Therefore, cleaning of the inner cutter becomes extremely easy.

By making the horizontally extending part protrude outward compared to the vertically extending part, and by extending the vertically extending part in a step-like manner, the blade part of the horizontally extending part is extended downwardly as shown in FIG. Since there are no blade grooves, the cut whiskers, etc. are discharged downward as they are. Furthermore, even long whiskers are discharged without remaining in the blade groove.

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 longitudinally extending portion is raised from the periphery of the cylindrical portion existing outside the base, the length of the longitudinally extending portion 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 the drawing]

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, and FIGS. 3 to 6 are for manufacturing the inner cutter for an electric shaver according to the present invention. The inner cutter blank for each process is shown, A in the figure
B is a front half-sectional view, B in the figure is a bottom view, FIG. 7 is a plan view showing one blade portion of the inner cutter, and FIG. 8 is a front view showing one blade portion of the inner cutter for an electric shaver according to a conventional example. A plan view and FIGS. 9 to 11 show an inner cutter blank manufactured through each process of a conventional method for manufacturing an inner cutter for an electric shaver, and A in the figure is a plan view of the inner cutter blank, and FIG. Middle B is a front view of one blade forming part;
FIG. 12 is a side view of one blade forming part in the same inner blade blank. In the drawing, 1... inner blade for electric shaver, 2...
Disc part, 5... Longitudinal extension part, 6... Horizontal extension part, 7...
...Blade part, 10...Inner blade blank, 11...Cylinder part,
12... Small tube part, 13... Ring plate part, 14...
Board surface, 15...blade groove.

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 outward, a vertically extending portion that projects in the axial direction is formed on the periphery of the base, and a horizontally extending portion that projects in the radial direction is integrally formed at the tip of the vertically extending portion. A blade portion is formed at the front end in the rotational direction of the horizontally extending portion, and a blade portion is formed between adjacent longitudinally extending portions of the longitudinally extending portion.
An inner cutter for an electric shaver, characterized in that each front face is formed into a U-shaped blade groove. 2. The inner cutter for an electric shaver according to claim 1, wherein the longitudinally extending portion is formed to be inclined in the direction of rotation. 3. The inner cutter for an electric shaver according to claim 1 or 2, wherein the longitudinally extending portion is formed in a step-like shape toward the outside. 4. The inner cutter for an electric shaver according to claim 1, 2, or 3, wherein the horizontally extending portion projects outward in the radial direction with respect to the longitudinally extending portion.