JPH0320273B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an inner blade of a rotary electric shaver, and includes grinding and polishing the rotary inner blade.
After installing bearings on both ends of the rotary inner blade,
The bearing is polished at the same time.

The inner blade of a rotary electric shaver is formed by protruding a blade part along the axial direction from the peripheral surface of a cylindrical base body, and the inner blade is centered around the axis and the cutting edge at the tip of the blade part is Shaving is performed while rotating the outer blade with lines running on the inner surface of the outer blade. The blade part is provided so as to project continuously from one end to the other end of the cylindrical base by giving a twist angle to the axial center of the inner cutter, as shown in FIG. 6a. As shown, the end has a sharp edge 5d. Therefore, when shaving is performed by pressing the outer surface of the outer cutter 5a against the skin as shown in FIG. It hits the edge 5d of the blade portion 5c protruding from the blade 5b, and the hit portion 5e is damaged, which not only causes loss of the outer blade 5a, but also damages the skin, making it impossible to shave with confidence. It was hot. For this reason, as shown in FIGS. 7a and 7b, it has been proposed that the edge 5d of the blade portion 5c is chamfered in a tapered or rounded shape to prevent the outer cutter 5a from being damaged by contact with the edge 5d. Chamfering the edge 5d of the blade portion 5c in this manner is extremely troublesome in processing, and also has the disadvantage that chamfering both ends of the blade portion 5c shortens the effective length L of the blade portion 5c. .

Therefore, the present invention has been made in consideration of the above points, and a blade portion is provided protruding along the axial direction of the circumferential surface of a cylindrical base body, which is the main body of the inner blade of a rotary electric shaver. After that, a bearing is attached to the end of the base body, and the tip of the blade is sharpened while simultaneously polishing the tip of the blade and the outer peripheral surface of the bearing. The tip of the blade and the outer circumferential surface of the bearing are completely aligned, and the edges at both ends of the blade are hidden by the bearing to prevent the outer blade from hitting the edge of the blade and being damaged during shaving. Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows the main body of the rotary inner cutter.
This figure shows a cylindrical base made of a material such as SUS440c with a protruding blade part, 1 is the cylindrical base, and the cutting blade 3 of the hob 2 is brought into contact with the peripheral surface of the base, and the hob is Rotate 2 at high speed. At this time, in order to give a desired helix angle to the blade part formed by cutting with respect to the axial direction, the hob 2 is placed around the body surface once around the base body.
The base body 1 is tilted to a desired helix angle with respect to the axial direction and brought into contact with the base body 1, and while being slowly rotated around the axis X, the base body 1 is sent in the direction of the axis X and its circumferential surface is cut by the cutting blade 3. The blade portion 4 is provided continuously extending from one end of the base body 1 to the other end along the axis X direction thereof and protruding at a desired twist angle with respect to the axis. FIG. 2 shows a side view of the base body 1 on which the blade portion 4 is formed in this manner. Reference numeral 5 denotes bearing mounting holes formed at both ends of the base body 1.

FIG. 3 shows bearings installed in the mounting holes 5 at both ends of the base body 1. The bearings 6 include a hollow cylindrical portion 6a and a disk-shaped portion protruding from the outer peripheral surface of one side of the cylindrical portion 6a. It consists of a flange portion 6b. The outer diameter d' of the cylindrical part 6a is slightly larger than the inner diameter d of the mounting port 5, and the outer diameter D' of the collar part 6b is larger than the outer diameter D of the base body 1 including the blade part 4. is also slightly larger than, or is the same as, or substantially the same as. The material of the bearing 6 is preferably an oil-impregnated material such as synthetic resin or brass.

Next, the blade attachment and polishing work will be explained with reference to FIG. First, the cylindrical portion 6a of the bearing 6 is press-fitted into the mounting opening 5, and brought into close contact with the end surface b of the base body 1 on the inner surface a of the collar portion 6b. (See figure a). As shown in the figure, the outer diameter D' of the collar 6b is slightly larger than the outer diameter D of the base 1, and the outer peripheral surface of the collar 6b protrudes slightly outward from the tip of the blade 4.

Next, as shown in FIG.
At the same time, the base body 1 is rotated around its axis X to polish the tip of the blade portion 4 and sharpen the tip of the blade portion 4. At this time, at the same time as the tip of the blade portion 4 is polished, the outer peripheral surface of the collar portion 6b of the bearing 6 is also polished. Figures c and d are a side sectional view and a perspective view of the inner cutter 8 of the lorry formed by polishing as described above. The tip of the portion 4 and the outer circumferential surface of the collar portion 6b completely match over the entire circumferential surface, and the edges 9 on both sides of the blade portion 4 are completely hidden by the collar portion 6b.

Rotary inner blade 8 formed as described above
When shaving with a rotary electric shaver, even if the outer cutter 11 is bent inward by the external force F applied to the skin as shown in FIG. 5, the edge 9 of the inner cutter 8 will be hidden by the bearing 6. Therefore, the inner surface of the outer cutter 11 will not be damaged due to contact with the edge 9, and shaving can be performed with peace of mind.
Further, unlike the above-mentioned conventional blade, there is no chamfering on both sides of the blade 4, so the effective length of the blade 4 does not decrease.

By the way, instead of forming the rotary inner cutter 8 as described above, it is possible to form the rotary inner cutter by attaching bearings having the same outer diameter as the outer diameter of the base body on both sides of the base body after the blade portion is sharpened. However, it is extremely difficult due to manufacturing technology to make the cross section of the base and bearing perfectly circular, and even if the bearings are mounted on both sides of the base in this way, the tip of the blade and the outer circumferential surface of the bearing will not match perfectly. First, the edges on both sides of the blade are partially exposed, and the outer cutter is damaged by the exposed portion. On the other hand, if the rotary inner cutter 8 is formed as described above, even if there are manufacturing errors in the base body 1 or the bearing 6,
By polishing both at the same time, the outer diameters of both can be perfectly matched and the edge 9 can be completely hidden.

Note that the present invention can be modified in various ways,
The shapes of the bearing and the bearing mounting opening of the base body are not limited to those of the above embodiments.

As explained above, the method for manufacturing the rotary inner cutter 8 according to the present invention involves forming a continuous blade part on the peripheral surface of the cylindrical base 1 from one end of the base 1 to the other end along the axis X direction. After arranging a plurality of blades 4 in parallel and protruding from each other, bearings 6 are mounted on both ends of the base 1 so that the outermost periphery of the bearings 6 is flush with or slightly larger than the tip of each of the blades 4 when mounted. Since the tip of the blade portion 4 is sharpened while simultaneously polishing the tip of the blade portion 4 and the outer peripheral surface of the bearing 6,
The tip of the blade part 4 and the outer circumferential surface of the bearing 6 can be completely aligned to hide the edge 9. Therefore, the outer cutter 11 will not be damaged by the edge 9, allowing you to shave with peace of mind and the finished product. There are various effects such as being able to manufacture a rotary inner cutter 8 with good precision.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.
The figure is a perspective view during the formation of the blade, Figure 2 is a side view of the base on which the blade is formed, Figure 3 is a perspective view of the bearing, and Figures 4a, b, c, and d are during the polishing process. A side sectional view and a perspective view after polishing, FIG. 5 is a partial side view of a rotary electric shaver, FIGS. 6 a and b are a partial perspective view and a partial side view of a conventional shaver, and FIGS. FIG. 3 is a partial side view of the object. 1...Cylindrical base, 4...Blade portion, 6...Bearing, 8...Rotary inner blade, X...Axis line.

Claims (1)

[Claims] 1 After a plurality of continuous blade portions 4 are juxtaposed and protruded from one end of the base 1 to the other end along the axis X direction on the circumferential body surface of the cylindrical base 1, both ends of the base 1 are The outermost periphery of each blade portion 4 in the mounted state is
The rotary rotary is equipped with a bearing 6 that is flush with or slightly larger than the tip of the blade, and sharpens the tip of the blade 4 while simultaneously polishing the tip of the blade 4 and the outer peripheral surface of the bearing 6. A method for manufacturing the inner blade of an electric razor.