JPH0447591B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing 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 rotated body.

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 blanks manufactured in 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 consists 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 with respect to the radial direction,
The bending angle is approximately 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
90 degrees to the opposite side), and then heat-treated so that the hardness becomes about 650 degrees in terms of Bitker's hardness.

Then, as shown in FIG. 15, if the blade forming part 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, the tip of the blade forming part 52 is Blade part 5
4 (see Figure 11).

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

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, the conventional method for manufacturing inner cutters has 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 blade is complex and small, making it difficult to process and manufacture, making it virtually impossible to use ceramic blades as inner blades 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.
Furthermore, 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 consumed 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 a method of manufacturing an inner cutter for an electric shaver that eliminates all such problems.

(Means for Solving the Problems) The present invention particularly relates to a method of manufacturing an inner cutter for an electric shaver using a ceramic material, and is characterized by having a flat surface perpendicular to the axis on the periphery of the rotated body 2. A forming step for forming the surface 3 into a ring shape, an adhesion step for fixing the flat ceramic plate 7 to the flat surface 3, and a cutting tool 23 cutting the ceramic plate 9 from the ceramic plate 9 to a blade inclined in the direction of rotation with respect to the rotated body 2. This method includes a blade cutting process for forming grooves 15 at predetermined intervals in the circumferential direction.

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

First, the method for manufacturing the inner cutter for an electric shaver according to the present invention will be explained in sequence for each step with reference to FIGS. 1 to 6. Figures 1 to 3, 5 and 6 show inner cutter blanks manufactured by each process,
FIG. 4 shows a ceramic plate, and in each figure, A is a front half-sectional view and B is a bottom view.

[Molding process]

The molding process consists of the following steps.

(Mold-cutting process) First, in a die-cutting process, a bowl-shaped inner cutter blank 10 shown in FIG. 1 is punched out from a plate material (not shown).
The inner cutter blank 10 consists of 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 step, the center of the disk portion 10a 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 step) Next, as shown in FIG. 2, the cylindrical portion 10b of the blank 10 was squeezed with a press to form a small cylindrical portion 12 having a reduced diameter, and at the same time, the cylindrical portion 12 was bent radially outward from the periphery of the opening end. Flange-shaped ring 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
2 is further narrowed from a predetermined intermediate position in the axial direction to the disk portion 10a side to reduce the diameter, as shown in FIG.
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. 5, 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. 6, the inner cutter blank 10 that has undergone the polishing process is used to form blade grooves 15 with a grinding tool 23 such as a rotary whetstone (for example, a diamond whetstone) having a disc shape and a rounded circumferential surface. . This blade groove 15
is formed in the shape of a notch from the plate surface of the ceramic plate 7 to the ring plate part 13 and further to the small cylinder part 12, and this blade groove 15 is cut to 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, as shown in FIG.
The optimal 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 forms an intersecting angle with respect to the outer cutter as shown in FIG. 10, and is optimally approximately 12°.

If the engaging member 31 that engages with the drive pole (not shown) is attached to the attachment hole 20 of the inner cutter main body 30 processed by the above steps, it is attached by caulking.
The inner cutter 1 shown in FIG. 1 is completed.

Next, FIGS. 7, 8, 10, and 11 show the inner cutter 1 manufactured by such a manufacturing method.
This will be explained with reference to the figures. FIG. 7 is a plan view showing one blade portion of the inner cutter, FIG. 8 is a front view showing the same blade portion, and FIG. 10 is an inner cutter for an electric shaver manufactured by the manufacturing method according to the present invention. FIG. 11 is a front half-sectional view of the inner cutter.

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 projecting in the axial direction are integrally formed on the periphery of the base 10c. This extending portion 4... is the second small cylinder portion 22.
The extension portions 4 extend obliquely in the direction of rotation from near the end thereof, and each extension portion 4 has a chevron shape that becomes narrower at the tip end and 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 this horizontal portion 9
A ceramic blade 6 is superimposed on the upper surface of the blade and integrated into one piece. 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. 8 and 11, 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 squeezing process may or may not be provided, and a similar third squeezing process may also be provided. Furthermore, selection of the magnitudes of angles θ1 and θ2 and selection of the magnitude of L1 are arbitrary.

Furthermore, in the present invention, individual ceramic blades 6 as shown in FIG. 8 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. Furthermore, although the invention 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 therein, or it may be similarly applied to the reciprocating type inner and outer cutters. can. Furthermore, arbitrary changes in the shape, structure, quantity, size, etc. of details that do not depart from the gist of the present invention are permitted within the scope of the present invention.

(Effects of the Invention) As described above, the method for manufacturing the inner cutter for an electric shaver according to the present invention includes a forming step of forming a ring-shaped flat surface perpendicular to the axis on the periphery of a rotated body, and a flat plate on the flat surface. The process includes an adhesion process for fixing the shaped ceramic plate, and a blade cutting process for forming blade grooves that are inclined in the rotational direction on the ceramic plate and the rotated body using a cutting tool at predetermined intervals in the circumferential direction. get the effect.

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 is possible to manufacture an inner blade that has many of the properties of a ceramic blade, such as excellent sharpness due to its high hardness, long life, and no rust.

Secondly, in addition to these effects, many effects can also be obtained from the viewpoint of the general inner cutter manufacturing method as described below.

As is clear from the comparison between the blade part of the inner cutter manufactured by the manufacturing method according to the present invention shown in FIG. 10 and the blade part (blade forming part) of the inner cutter according to the conventional example shown in FIG. According to the method, the blade part of the inner cutter is formed into a horizontal part that protrudes outward and has a relatively small front surface area according to an optimal embodiment, so that shavings and skin oils are not absorbed into the blade part and the horizontal part. It becomes difficult to adhere. Therefore, cleaning of the inner cutter becomes extremely easy. In addition, the horizontal part is made to protrude outward compared to the extended part, and the extended part extends outward in a step-like manner, so that shavings, etc. can pass through the blade groove without adhering to the inner blade. It is ejected downward from the blade.

There is a cylindrical portion on the outside to form the base into a bowl shape. Therefore, the weight distribution is biased to the outside compared to the past, and the inertial force is increased, which reduces rotational speed fluctuations due to temporary loads and provides stable performance.

Since the extension part stands up from the periphery of the cylindrical part that exists outside the base, the length of the extension part can be made as short as possible, and there is no need to bend it at the base as in the conventional case. Therefore, the mechanical strength can be increased, and stable performance can be maintained even under temporary loads as described above.

Since the inner cutter blank is formed into a bowl shape, the shape is simplified, the cost of the press mold can be significantly reduced, and the tool life can be extended. Furthermore, automatic material feeding using a parts feeder or the like becomes easy.

The simplification of the shape of the inner cutter blank reduces shape distortion during pressing, and since spring back and the like as in the conventional method do not occur, highly accurate machining can be performed. This allows constant sharpness to be maintained at all times. In particular, in the conventional press type, the intersecting angle of the blade portion with respect to the outer cutter varies within an angle range of 0 to 20 degrees, but in the present invention, this variation is almost eliminated.

Since the ring plate portion is formed by pressing, the plate surface of the plate portion, which becomes the blade surface, can be easily flattened. Therefore, surface finishing can be easily performed by automatic polishing, the polishing allowance is small, and the polishing time is extremely short. Moreover, since the shape is highly precise, post-processing such as polishing to correct irregularities in each blade part is unnecessary, and the polishing process can be significantly streamlined.

In the conventional press method, the number of blades is limited to about 16, but the inner blade according to the present invention can have up to about 32 by reducing the thickness of the grommet grinding tool.

[Brief explanation of the drawing]

FIGS. 1 to 3, 5 and 6 show inner cutter blanks manufactured by each process for manufacturing the inner cutter for an electric shaver according to the present invention, and FIG. 4 shows a ceramic plate. , A in the figure is a front half-sectional view, B in the figure is a bottom view, FIG. 7 is a plan view showing one blade part of the inner blade, FIG. 8 is a front view of the same blade part, and FIG. 9 is a conventional one. FIG. 10 is a plan view showing one blade part of an inner cutter for an electric shaver according to an example, FIG. 10 is a plan view of the inner cutter for an electric shaver manufactured by the manufacturing method according to the present invention, and FIG. 12 to 14 show inner cutter blanks manufactured through each process of the conventional method for producing inner cutters for electric shavers, and A in the figure shows the plane of the inner cutter blank. In the figures, B 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)

[Claims] 1. A method for manufacturing an inner cutter for an electric shaver, comprising the following steps: (a) A forming process of forming a ring-shaped flat surface perpendicular to the axis on the periphery of the rotated body, (b) An adhesion process of fixing a flat ceramic plate to the flat surface, (c) Cutting the ceramic plate with a cutting tool. 2. A blade cutting step of forming blade grooves inclined in the rotational direction on the plate and the rotated body at predetermined intervals in the circumferential direction; 2. The forming step comprises the following steps. A method for manufacturing inner blades for electric razors. (a) A die-cutting process in which a bowl-shaped inner cutter blank with a cylindrical portion extending a predetermined length in the axial direction from the periphery of the disc portion is extracted from the plate material; (b) A small cylindrical portion in which the diameter of the cylindrical portion is reduced by narrowing the cylindrical portion. and bending radially outward from the periphery of the opening end to form a ring plate portion having the flat surface.