JPH06225981A - Spiral cutter - Google Patents

Abstract

PURPOSE:To achieve a prevention of the flying of dust from a spiral small blade, deflection and the generation of heat of the spiral small blade in a spiral blade in which a side end of the root of the band-shaped spiral small blade 2 comprising an elastic material is buried into the circumferential surface of a cylindrical base as deformed being twisted. CONSTITUTION:A plurality of through holes 3 are arranged in a row on the side 2a of an edge exposed from a base 1 of a spiral small blade 2 in the longitudinal direction of the small blade. This enables the preventing of the flying of dust from the spiral small blade 2 and the lowing of the generation of heat of the spiral small blade.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade used in a pencil sharpener, a pill remover, etc., and more particularly to a blade having a spiral edge line.

[0002]

2. Description of the Related Art As a spiral blade of this type, for example, a strip-shaped spiral blade made of a plurality of elastic materials is provided on a peripheral surface of a cylindrical base as disclosed in Japanese Patent Laid-Open No. 4-131299. Some of them are buried in a twisted state.

This is advantageous in that productivity can be improved and cost can be reduced as compared with the conventional spiral blades in which a spiral blade is cut out from a tubular or rod-shaped blade material using a hobbing machine. . In addition, since the spiral blade made of elastic material is also embedded in the base in the state of being twisted and deformed, the edge of the blade tip side is opposite to the direction deflected by the cutting resistance received from the object to be cut such as hair. Since the twisting stress of (3) acts, the bending at the time of cutting can be suppressed as small as possible and the cutting condition becomes good.

[0004]

However, in the above-mentioned spiral blade, for example, when it is applied as a rotary inner blade of an electric razor, hair is generated by the cooperative action of the spiral small blade of the inner blade and the fixed outer blade. It is cut, but at this time, the hair debris already accumulated on the peripheral surface of the base rises between the spiral blades and easily blows out from the fixed outer blade, especially the hair blowing phenomenon is remarkable at the initial stage of starting the electric razor. It was easy to appear in.

Further, the blade edge of the spiral small blade is brought into sliding contact with the inner surface of the fixed outer blade at high speed rotation, so that sliding contact heat is generated. The sliding contact heat generated on the cutting edge may reduce the life of the cutting edge, and the heat of the cutting edge may increase the surface temperature of the fixed outer blade, which may exceed a specified value (for example, 20 deg). give.

[0006] If the spiral small blade is thin, it can be attached only by cylindrical polishing, which is very advantageous in processing the cutting edge, and can be easily twisted, which is also advantageous in the surface of insert molding. On the other hand, it is easy to bend due to sliding resistance with the inner surface of the fixed outer blade and cutting resistance such as hair, and the bending deformation of this spiral blade extends to the longitudinal end of the spiral blade 2, and this end is fixed. At the same time as it comes out of the sliding contact area with the inner surface of the outer blade, it elastically returns to its original shape, and due to this return action, the blade tip is easily caught by the hair introduction hole of the fixed outer blade and easily breaks, and at this time an unpleasant noise is produced. It was discovered that it may occur.

However, if the plate thickness of the spiral small blade is increased to, for example, 1 mm or more, it will not bend due to sliding resistance with the inner surface of the fixed outer blade or cutting resistance such as hair, but the desired cutting It takes a lot of time to perform a cutting process or a shaping polishing process for forming a predetermined rake angle or a clearance angle in order to obtain the blade angle, and it becomes difficult for the base plate to be twisted and deformed during insert molding.

An object of the present invention is to solve such a problem and to embed a plurality of spiral blades on the peripheral surface of a cylindrical base with the blade base end having a helix angle. The spiral blade is intended to reduce the blowout of chips by modifying the structure of the spiral blade itself. Another object of the present invention is to reduce the bending at the end of the spiral blade while ensuring the ease of torsional deformation of the spiral blade. Still another object of the present invention is to improve the durability of the edge of the spiral blade.

[0009]

According to the present invention, as shown in the drawing, the blade tip side 2a exposed from the base 1 of the spiral blade 2 is shown.
A plurality of through holes 3 are arranged in a row in the longitudinal direction of the small blade. It is arbitrary that the through holes 3 are provided at a predetermined pitch over the entire length in the longitudinal direction of the small blade, or at a predetermined pitch only near the center thereof.

[0010]

In this case, the presence of the through hole 3 can reduce the air flow between the spiral blades 2 during the rotation of the spiral blade, and reduce the blowout and scattering of chips. Further, by arranging the through holes 3 on the blade tip side 2a of the spiral blade 2, the specific heat of the blade 2 can be reduced,
Even when rotating at high speed, heat generation at the cutting edge can be reduced.

Further, even if the spiral blade 2 has a slightly increased plate thickness, the presence of the through hole 3 suppresses the rigidity and facilitates the torsional deformation thereof. Furthermore, the rigidity of the small blade 2 can be easily adjusted by increasing the through hole 3 on the cutting edge side 2a of the spiral small blade 2 so that the rigidity of the small blade 2 increases from near the central portion in the longitudinal direction of the small blade to near both ends. With this adjustment, the flexural deformation at the end of the spiral blade 2 can be suppressed.

[0012]

1 and 2 show an embodiment of a spiral blade according to the present invention. This spiral blade is made of thin stainless steel strip steel, for example 13 chrome steel (thickness 0.1 to 0.3 m) on the peripheral surface of a plastic cylindrical base 1.
A plurality of spiral blades 2 made of m) are insert-molded with a predetermined helix angle. A rotary shaft 4 is projected from the center of both ends of the base 1, and this is also insert-molded at the same time as the spiral blade 2. The blade tip side 2a exposed from the base 1 of the spiral blade 2 has
As shown in FIG. 3, through holes 3 of the same size are arranged in a row in the longitudinal direction of the small blade at equal pitches.

During insert molding of the spiral blade 2, the spiral blade 2 is inserted and held in a state where internal stress remains by twisting and deforming the spiral blade 2 at a predetermined twist angle on the inner circumference of the cavity of the base molding die. By injecting and filling the cavity with the molten resin, the cylindrical base 1 is formed, and at the same time, the blade base end 2b of the spiral blade 2 remains twisted and deformed. The surface is integrally molded to a predetermined depth. The twisting deformation of the spiral blade 2 is smaller than or larger than a predetermined twist angle before being inserted into the mold, and after the insertion, the mold is forced to have a predetermined twist angle, or the metal is left flat. Various methods are conceivable, such as a method of inserting into a mold and forcibly deforming it.

In this case, since the spiral small blade 2 has the through hole 3, even if the spiral small blade 2 has a slightly large plate thickness in order to increase the rigidity of its end portion in the longitudinal direction, before insert molding into the base 1. The torsional deformation could be easily added to it. In addition, it is preferable to provide a notch or a hole 5 over the entire length of the spiral blade 2 at the blade-side end 2b so that the resin of the base 1 will not come around and escape.

Results obtained when this spiral blade is applied to the inner blade of the rotary electric shaver shown in FIG. 3, for example, will be described. Since the through holes 3 are arranged in a row at a predetermined pitch in the longitudinal direction of the small blades on the blade edge side 2a exposed from the base 1 of the spiral small blades 2, there is a gap between the spiral small blades 2 and 2 during rotation of the spiral blade. Winding was reduced, and blown dust from the outer blade 7 and scattering could be reduced.

As described above, the spiral small blade 2 acts as if the blade portion between the through holes 3 and 3 was divided by the adjacent through holes 3 so that it is easily twisted and deformed, and the plate thickness is accordingly increased. Can be increased to increase the rigidity of the end portion. Therefore, even if one end of the spiral blade 2 is bent by the sliding resistance with the fixed outer blade 7 or the cutting resistance received from the bristles, even if this deformation extends to the other end side, the other end Deflection can be well suppressed by the rigidity of the portion, and the amount of deformation that the other end of the fixed outer blade 7 comes out of the sliding contact area with the inner surface and returns to the original shape at the same time is small.
It is less likely that the fixed outer blade 7 is pierced by the elastic restoring action of the end portion of the spiral small blade 2 as in the conventional case. In addition, since the blade portion between the through holes 3 and 3 easily bends independently, the deformation vibration at the time of whisker cutting becomes small, and a high-frequency and nice cutting sound can be obtained. Particularly, in the electric shaver of the rotary inner blade, since the entire blade edge 2a of the spiral blade 2 does not slidably contact the outer blade 7 all at once, but the slidable contact position moves along the twist thereof. The sliding contact portion of the cutting edge which is slid on and has a cutting action is separated from the outer blade 7 at the next moment, whereby the deformation vibration during cutting vibrates with a lingering sound, and a comfortable cutting sound is obtained.

As a deflection suppressing means at the end of the spiral blade 2, as shown in FIG. 1, a flange 6 for filling the space between the spiral blades 2 adjacent to one end of the base 1 is provided on the base 1. It is more preferable that the flange 6 is formed integrally with or is separately fitted and fixed between the spiral blades 2. That is, by providing the flange 6 in this way, the end of each spiral blade 2 is sandwiched between the adjacent flanges 6 and 6 and is prevented from falling down. This is because it can be well suppressed in combination with the increased plate thickness. The flange 6 can be provided not only at one end of the base 1 but also at the other end.

Further, by arranging the through holes 3 in the spiral small blade 2 in a row, the specific heat of the small blade 2 can be reduced, the heat generated at the blade edge can be reduced even when rotating at a high speed, and the blade can be shaved without feeling uncomfortable. I was able to.

4 to 6 show another embodiment. In this structure, the rigidity of the spiral blade 2 is the weakest in the vicinity of the central portion in the longitudinal direction of the blade and becomes stronger toward both ends. That is, in FIG. 4, on the blade edge side 2a of the spiral blade 2, through holes 3 of the same size are provided at the smallest pitch near the center in the longitudinal direction of the blade and at a larger pitch toward both ends. In FIG. 5, the through hole 3 is formed on the blade edge side 2a of the spiral blade 2 to be the largest hole near the center of the blade in the longitudinal direction, and to be gradually smaller toward both ends. In FIG. 6, a through hole 3 is provided on the blade edge side 2a of the spiral blade 2 only near the center in the longitudinal direction of the blade. As a result, it is possible to more effectively achieve the above-described suppression of bending at the end of the spiral blade 2.

The shape of the through hole 3 is not limited to the round hole shape, but may be a square hole as shown in FIG. Further, when insert-molding the spiral blade 2 on the base 1, instead of injection-molding with plastic as in the above embodiment, die-casting with a molten metal such as an aluminum alloy can be performed. Further, as shown in FIG. 8, the blade edge 2a of the spiral blade 2 can be formed in a lightning bolt shape, whereby the object to be cut can be reliably captured without slipping on the blade edge. In this case, the edge portion A of the lightning edge 2a is delayed (escape) from the lead of the spiral blade 2 so as not to hit the hair introduction hole of the outer blade 7 of the electric razor. Is preferred.

[0021]

According to the spiral blade of the present invention, a plurality of through holes 3 are arranged in a row in the longitudinal direction of the small blade 2 on the cutting edge side 2b exposed from the base 1 of the small spiral blade 2. It is possible to reduce the wind-up between the two and reduce the blowing and scattering of chips. In addition, since it is possible to easily apply the torsional deformation when the spiral small blade 2 is embedded, it is possible to suppress the bending at the end of the spiral small blade 2, so that the outer blade of the electric razor can be prevented from being damaged. In addition, since it is possible to reduce the heat generation of the blade edge, it is possible to prevent its thermal deterioration and improve the durability, and it is also possible to suppress the surface temperature rise of the outer blade of the electric razor and make the user not feel the heat, In particular, it is most suitable as a rotary inner blade for an electric razor.

[Brief description of drawings]

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

FIG. 2 is a developed front view of a spiral blade.

FIG. 3 is a schematic front view of a rotary electric shaver having a spiral blade attached thereto.

FIG. 4 is a developed front view of a spiral blade according to another embodiment.

FIG. 5 is a developed front view of a spiral blade which shows another embodiment.

FIG. 6 is a developed front view of a spiral blade according to still another embodiment.

FIG. 7 is a developed front view of a spiral blade according to still another embodiment.

FIG. 8 is a perspective view of a blade tip shape of a spiral blade according to another embodiment.

[Explanation of symbols]

 1 Base 2 Spiral blade 3 Through hole

Claims (1)

[Claims] 1. A strip-shaped spiral blade 2 made of an elastic material.
While maintaining the state of being twisted and deformed,
In a spiral blade embedded in the peripheral surface of a cylindrical base 1, a plurality of through holes 3 are arranged in a row in the longitudinal direction of the small blade on the blade tip side 2a exposed from the base 1 of the spiral blade 2. A spiral blade that is characterized by.