JPH06327853A - Spiral edged tool - Google Patents

Abstract

PURPOSE:To enhance productivity by constituting a cylindrical spiral edged tool to be used for an electric pencil sharpener or the like out of half edged bodies that have been longitudinally divided into two parts, and by constituting each half edged body out of a knife arranged along the spiral edge line and a knife holder. CONSTITUTION:The spiral edged tool is made up by butting and integrally joining two half edged bodies 1, 1, and a turning shaft 2 is penetrated in its center. Each half edged body 1 is formed by embedding a plurality of knives 4 in the circumferential surface of a knife holder 3 of a semicircular sectional shape with a prescribed inclination (spiral angle beta) to the axis of the shaft. The respective holders 3, 3 of these half edged bodies 1, 1 are made to butt each other, and also the edges in the spiral direction of the knives 4 on the respective holders 3 are made to butt each other for obtaining a spiral edge line. The knife holder 3 is made up by injection molding with resins such as PBT resin, preferably polyacetal, nylon, or the like, and the knife 4 is insertedly formed on the circumferential surface of the holder 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric sharpener, an electric ball remover, an inner blade of a rotary electric shaver, etc., and a blade having a spiral edge line.

[0002]

2. Description of the Related Art As a spiral blade of this kind, for example, as disclosed in Japanese Utility Model Application Laid-Open No. 50-25790, a spiral groove is provided on the peripheral surface of a cylindrical holder, and a linear blade is provided in the spiral groove. Some are embedded via a spring member. Further, as disclosed in Japanese Utility Model Laid-Open No. 2-67969, there is one in which a cutting blade is cut out from a tubular or rod-shaped blade material by using a hobbing machine to manufacture spiral blades one by one.

[0003]

However, in the case of the former of the above-mentioned two conventional examples, a process of embedding a single long linear blade body while making a helix angle over the entire length of the spiral groove is required. However, this process is not easy, especially when the linear blade body is composed of a coil spring, it must be buried in the spiral groove while straightening it against the spring property, so that work is extremely difficult. However, it is not suitable for mass production and the cost is high.

In the latter hobbing process, it takes a lot of time to manufacture one spiral blade, which results in low productivity, high cost, and short tool life. All of the above conventional examples have the drawbacks of low productivity and high cost.

An object of the present invention is to form a pair of half-split blade objects in a cylindrical spiral blade having a cutting edge line in a spiral shape along the longitudinal direction of a rotating shaft, and to butt-join them integrally. By adopting a structure in which it is completed in a cylinder shape with the aim of improving productivity and reducing costs.

[0006]

According to the present invention, as shown in the drawing, a pair of half-split blade objects 1, 1 divided into two in the circumferential direction are butted and integrally joined. Each half-cutting object 1
Consists of a small blade 4 having a cutting edge 4a forming a spiral cutting edge line, and a small blade holding body 3. The small blade 4 is a semi-ellipse whose cutting edge 4a is semicircular when viewed in the axial direction. The blade holder 3 is formed in a shape and is held and fixed with a predetermined twist angle β. The ends of the small blade 4 of one half-cutting blade object 1 in the twisting direction and the ends of the small blade 4 of the other half-cutting blade object 1 in the twisting direction are abutted or overlapped with each other to connect both small blades 4 and 4. It has a spiral shape.

[0007]

The small blade 4 before being held by the small blade holder 3 can be mass-produced by pressing or etching.

Since each of the small blades 4 is formed in a shape of a semi-elliptical shape such that the cutting edge 4a becomes a semi-circular shape when viewed in the axial direction, the half-divided blade objects 1.1 having the small blades 4 are separated from each other. By combining them, a continuous spiral cutting edge line can be obtained, and this rotation does not hinder the cutting function of the object to be cut.

Further, since each of the small blades 4 does not have a winding tendency like a coil spring and has a semi-elliptical flat plate shape, it can be easily embedded and inserted into the small blade holder 3. You can do it.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a spiral blade after completion of assembling, which comprises two half-split blade bodies 1.1 abutting and integrally coupled to each other, and a rotary shaft 2 passing through the center thereof. As shown in FIG. 4, the half-cutting blade object 1 has a plurality of small blades 4 formed on a peripheral surface of a small blade holder 3 having a semicircular cross section at a predetermined inclination angle (twist angle β) with respect to an axis. Buried in
As shown in FIG. 1 and FIG. 2, the half-split blade objects 1.1 are made to abut against each other, and the ends of the small blades 4 on both small blade holders 3 are twisted. A spiral cutting edge line is obtained by abutting each other. Instead of a joining method in which the ends of the small blade 4 in the twisting direction are butted against each other, the ends may be superposed. In the spiral blade of the illustrated example, three small blades 4 are embedded in the peripheral surface of one small blade holder 3 to form a total of three spiral cutting edge lines.

The small blade holder 3 of the half-split blade object 1 is injection-molded in a semicircular cross section with, for example, a resin such as PBT resin, preferably polyacetal or nylon having excellent lubricity, and at the same time, a small surface is formed on the peripheral surface thereof. The blade 4 is insert-molded. In this case, the small blade 4 is inserted, held and set in a spiral groove provided in the inner periphery of the cavity of the molding die while being twisted and deformed so that internal stress remains. Then, since the small blade 4 is insert-molded in the small blade holding body 3 in a state of being torsionally elastically deformed, a twisting stress in a direction counter to the direction in which the cutting edge 4a is deflected by the cutting resistance received from the workpiece is generated. Therefore, the bending of the small blade 4 at the time of cutting can be suppressed and the sharpness can be improved.

The one small blade 4 is, for example, SUS40.
A stainless steel plate such as 3J2 is pressed, but it is formed in a semi-elliptical shape as shown in FIG. 3 so that the cutting edge 4a becomes a semi-circular projection line when viewed from the axial direction as shown in FIG. When the blade edge 4b of the small blade 4 is embedded in the peripheral surface of the blade holder 3 to a predetermined depth, the blade 4 is provided with a through hole or a notch near the blade edge 4b as shown in FIG. Part 5
Is provided over the entire length thereof or partially, but it is preferable to set the size and arrangement such that the torsional deformation is not partially relaxed in the embedded state. For this purpose, it is most stable if all the through holes are buried as shown in FIG.

Half-split blade object 1.1 obtained as described above
The small blade holders 3, 3 are butted against each other and their joint surfaces are integrally joined. The connecting means is as shown in FIG.
And, as shown in FIG. 4, in addition to press-fitting the concave portion 6 provided on the joint surface of the one small blade holder 3 to the convex portion 7 provided on the joint surface of the other small blade holder 3, ultrasonic welding It is also possible to bond them together with an adhesive or the like. In this connection, the ends of the small blade 4 in the twisting direction are butted against each other so as to form a continuous spiral shape. Next, the small blade 4 is hardened, and then centered or cylindrically ground to form a blade. Finally, the rotary shaft 2 is press-fitted into the shaft hole 9 formed at the center between the joint surfaces of the small blade holders 3 to obtain the final product.

In the above-mentioned embodiment, the small blade 4 is embedded in both of the half-cutting blade objects 1 butting each other with the same helix angle β, but instead of this, as shown in FIG. The twist angle β of the small blade 4 of 1 may be different from that of the other small blade 4.

The small blade holder 3 is made of the above-mentioned materials,
For example, it can be molded with a high specific gravity composite plastic filled with a metal powder such as iron powder, or can be die-cast with a molten metal such as an aluminum alloy or zinc. If the small blade holder 3 is formed of high specific gravity composite plastic or molten metal as described above, the inertia force at the time of high speed rotation of the small blade holder 3 is increased even when the diameter of the blade is reduced, and the blade edge of the small blade 4 prevents the blade from being covered. It is possible to enhance the impact cutting action of the cut object. Instead of insert molding, the small blade 4 may have a spiral groove formed on the peripheral surface of the small blade holder 3 and the small blade 4 may be inserted and fixed in this groove.

6 to 8 show still another embodiment.
In this embodiment, as the small blade holder 3 of the half-split blade object 1,
Using a plurality of connecting pipes 10, the small blade 4 formed in a semi-elliptical shape has a plurality of holes 11 as in the case of the above embodiment,
The half-split blade object 1 is constructed by inserting the connecting pipe 10 into the hole 11. The connecting pipe 10 is made of a metal such as aluminum, brass, stainless steel, etc., which is softer than the blade 4, and the hollow inside of the connecting pipe 10 serves as a mechanical or fluid pressure expanding means, for example, a burnish bar P as a mechanical means. (See FIG. 8) is pushed in to expand the connecting pipe 10 in the diametrical direction and fix the small blade 4 to the outer periphery of the connecting pipe 10.

The pair of half-divided blade bodies 1 are butted against each other and integrally coupled to each other to obtain a cylindrical blade body having a spiral shape with continuous cutting edge lines as shown in FIG. It is similar to the case. As a connecting means, a semicircular connecting plate 12 may be inserted and fixed to the end of the connecting pipe 10 as in the case of the small blade 4, and the connecting plates 12 and 12 may be abutted and connected. One or two or more connecting pipes 10 can be used and may be set in consideration of the fixing strength, the pipe diameter, and the small blade diameter. The number of small blades 4 can also be changed arbitrarily. As a means for forming the small blade 4, etching processing or the like can be adopted in addition to press processing.

[0018]

According to the present invention, since a large number of small blades 4 can be mass-produced and the small blades 4 can be easily embedded or inserted into the small blade holder 3, they can be tubular or hobbed using a hobbing machine. Compared to the one that cuts out from a rod-shaped blade material, the processing man-hours are the same or less, and the blade production amount per unit time can be greatly increased.

[Brief description of drawings]

FIG. 1 is a front view of a spiral blade.

FIG. 2 is a sectional view taken along line YY in FIG.

FIG. 3 is a front view of a small blade.

FIG. 4 is an exploded perspective view of a spiral blade.

FIG. 5 is a front view of a spiral blade showing another embodiment.

FIG. 6 is a front view of a spiral blade of another embodiment.

7A is a side view of the spiral blade shown in FIG. 6,
(B) is a side view showing a state in which the spiral blade is separated.

8 is a perspective view of the half-cutting blade object of the spiral blade shown in FIG.

[Explanation of symbols]

 1 Half-divided blade object 2 Rotating shaft 3 Small blade holder 4 Small blade

Claims (1)

[Claims] 1. A cylindrical spiral blade having a cutting edge line spirally extending along the longitudinal direction of a rotary shaft 2 in which a pair of half-divided blade objects 1, 1 divided in the circumferential direction are butted against each other. The half-divided blade object 1 is composed of a small blade 4 having a blade edge 4a that constitutes the spiral blade edge line and a blade holder 3, and the blade 4 has a blade edge 4a. Has a semi-elliptical shape such that it is a semi-circle when viewed from the axial direction, and is held and fixed to the small blade holder 3 with a predetermined helix angle β. It is characterized in that the ends in the twisting direction and the ends in the twisting direction of the small blade 4 of the other half-cutting blade object 1 are abutted or overlapped with each other so that both small blades 4 and 4 are formed in a continuous spiral shape. Spiral knife.