JPS6057989B2 - How to polish the inner blade of a reciprocating electric razor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of polishing an inner blade of a reciprocating electric shaver.

Conventionally, in this type of electric shaver, the inner cutter body, which is assembled into a semi-cylindrical shape by fixing a plurality of inner cutter blades to a connecting member in a skewer shape, is held in a polishing fixture and is shaken. It is customary to polish the cutting edge of the inner cutter by applying it to a rotating grindstone while rotating the inner cutter in the same direction or in the same direction.

However, according to the above method, when rocking,
The grinding conditions differ depending on whether the grinding wheel is rotated in the direction opposite to the rotation of the grinding wheel or in the same direction as the rotating direction of the grinding wheel. The polishing surface of the inner cutter, especially the polishing surfaces at both ends, which are the parts that first come into contact with the whetstone, has the drawback of becoming rough.Also, even when polishing while rotating in the same direction, the cutting edge of the inner cutter body is still intermittently exposed to the whetstone. Because of this, the polished surface is likely to become rough, similar to the above.

In order to eliminate the above drawbacks, we prepared two semi-cylindrical inner blades, made the base surfaces of these inner blades face each other, and used an assembly jig that was attached to both longitudinal end surfaces. A method has been implemented in which both of the inner blade bodies are fixed together to form a cylindrical block to be polished, and this block is polished centerlessly.

By holding the two inner cutters together to form a cylindrical block to be polished, the cutting edge of the inner cutter can be polished with high efficiency without having to fix the block to a jig during polishing. Moreover, it was possible to reliably prevent roughening of the polished surface.

However, a new problem posed here is a means for fixing the pair of inner blades in a hugging manner.

In other words, conventionally, as shown in FIG.
one pair of positioning pins 72, 73, respectively corresponding to
is protruded from one side of a disk-shaped assembly jig 74 made of synthetic resin,
By press-fitting a pair of pins 72 and 73 into each opening of the pipe-shaped connecting member 75 of one inner blade body 71 and each opening of the pipe-shaped connecting member 75 of the other inner blade body 71, both inner blade bodies At the same time as fixing the inner blades 71 and 71,
, 71 to be polished to a perfect circle. However, in the above configuration, the distance X between the pins 72, 73, 72, 73 and the distance Y between the pins 72, 73 are different, and the direction when installing the assembly jig 74 must be taken into consideration, which makes the work difficult. This is troublesome, especially if the connecting member 75 of the inner cutter bodies 71, 71 is misaligned, the positioning pins 72, 73 of the assembly jig 74 will force the assembled inner cutter body 71 into position. As shown in Fig. 8, it tends to deform into a drum shape, and polishing is performed linearly in this drum-stretched state, so when the inner blade bodies 71 are disassembled after polishing, the drum-stretched state is Due to the restoration, the cutting edge portion 77a of the inner cutter blade 77 may become concave, resulting in poor adhesion with the outer cutter. Therefore, this invention forms an engagement hole located at the axis of the cylindrical block to be polished when the inner cutters are assembled to each other at the base end of a reinforcing plate fixed to both end surfaces of the inner cutter, By forming a positioning pin corresponding to this engagement hole on the assembly jig, it is possible to easily assemble both inner blade bodies, and also prevent deformation of the block to be polished and perform centerless polishing appropriately. It is something.

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, reference numeral 1 denotes an inner blade body, and a plurality of inner cutter blades 2 (21, 22, ... 2n) formed in a semicircular shape from a thin stainless steel plate with a thickness of 100 to 120 μm are fitted with a brass vibrator. By penetrating the nickel-plated connecting member 3 in the shape of a skewer and expanding it in the radial direction, the inner cutter blade 2
to the connecting member 3 at a predetermined interval. They are arranged in series and fixed.

When fixing this inner cutter blade 2 to the connecting member 3, reinforcing plates 4 are fixed to both ends of the connecting member 3, and an inner cutter body is attached to the central part to be locked to an inner cutter holder (not shown). The locking plate 5 is fixed at the same time.

The reinforcing plate 4 is attached to the cutting edge 2a of the inner cutter blade 2 as shown in FIG.
It consists of a semicircular tip 4a with a slightly smaller diameter and a base 4b having a protrusion 6 in the center.
An engagement hole 7 is formed at the axis P of the semi-cylindrical inner cutter body 1. The protrusion 6 is formed in such a shape that an imaginary circle of which the outer edge 6a is a part is substantially in contact with the outer peripheral surface of the connecting member 3. Next, the grinding of the semi-cylindrical inner cutter body 1 will be explained.

First, prepare two semi-cylindrical inner blade bodies 1, and each of these inner blade bodies 1
A cylindrical polished block 8 is constructed by placing the base surfaces of the blocks facing each other as shown in FIG.

At this time, each inner cutter body 1 has a reinforcing plate 4 and a mating inner cutter blade 21,
2. The assembly pitch is shifted so that the reinforcing plate 4 is inserted between 2n-1 and 2n, and the outer edge 6a of the protrusion 6 of the reinforcing plate 4 comes into contact with the outer peripheral surface 3a of the mating connecting member 3. As a result, the engagement holes 7 of the reinforcing plates 4 of both inner cutter bodies 1 are overlapped at the position of the axis P as shown in FIG.
In addition, as shown in FIG. 3, the inner cutter body 1 has inner cutter blades 21,
2n...2n are supported at a predetermined interval e (1.3Tfn), especially between the inner cutter blades 21 and 22 into which the reinforcing plate 4 is inserted and between 2n-1 and 2. . In consideration of the positional deviation and slight warpage of the reinforcing plate 4, the distance between the reinforcing plates 4 and 4 is set to be slightly longer than e''(e''=1.5 wm). Next, in this state, the two inner blade bodies 1, 1 are assembled and fixed using the assembly jig 9 shown in FIG. a positioning pin 10 that is inserted into the engagement hole 7 of the reinforcing plate 4 to position the inner blades 1, 1; and one inner blade 1 that is on a straight line passing through the engagement hole 7. Lock pins 11, 11 for preventing rotation are fitted into the opening of the first connecting member 3 and the opening of the connecting member 3 of the other inner cutter body 1, respectively, and are provided protrudingly. The reason for this is to adjust the level difference of the reinforcing plate 4 that is shifted due to the assembly pitch.The diameter of the assembly jig 9 is a size that does not exceed the diameter of the cylindrical block to be polished 8. It is not limited to the disk shape as shown in the figure, but may be rectangular, for example.A positioning pin 10 of the assembly jig 9 is inserted into the engagement hole 7 with a lock pin 11,
11 into the openings of the connecting member 3 of both inner cutters 1, 1, the two semi-cylindrical inner cutters 1, 1 are firmly fixed as a cylindrical polished block 8 as shown in FIG. After the block 8 is fixed, centerless polishing is performed on the block 8, so that the cutting edge portions 2a of each of the inner cutter bodies 1 are simultaneously and evenly polished, and the polished surfaces are not roughened.

In this case, the assembly pitch when assembling each inner blade body 1 is
Since the inner cutter blades 2 of both inner cutter bodies 1 are set to exist in corresponding positions, the abrasive force is evenly applied and uneven wear is prevented.

In particular, since the assembly jig 9 is used to position both inner cutters 1, 1 at the axis P of the cylindrical block to be polished 8,
Even if there is a crack in the connecting member 3, the roundness of the block 8 is ensured regardless of this, and the cylindrical polished block is not warped or deformed during assembly as in the conventional case. After disassembly, the cutting edge portion 2a of the inner cutter body 1 is evenly ground. Furthermore, since the assembly jig 9 is attached to the axis of the cylindrical block to be polished 8 using the positioning pin 10, the directionality during attachment is taken into consideration compared to the conventional case of fixing on four sides in the circumferential direction. There is no need to do this, and the work can be done efficiently.

Further, since the rotation of both inner cutter bodies 1 is restricted to some extent by the protrusion 6 of the reinforcing plate 4 coming into contact with the connecting member 3 of the mating inner cutter body 1, the positioning pin 10 is engaged. If it is inserted into the hole 7, seretarless polishing can be performed without any trouble, but by protruding the lock pin 11 that fits into the opening of the connecting member 3 as in this embodiment, the inner cutter body 1 is reliably prevented from rotating, and even better selectorless polishing can be performed.

Particularly in this case, if the continuous portion of the positioning pin 10 and the lock pin 11 is formed using a deformable soft material, the positioning pin 10 that determines the roundness and the inner cutter body 1 in the tied state Since the rotation stopper lock pin 11 is effectively separated, when both pins 10 and 11 are inserted into the inner blade 1, there is no difference in insertion allowance due to misalignment between the engagement hole 7 and the connecting member 3. The influence is absorbed by the soft material, and the roundness during polishing can always be accurately maintained.

The above-mentioned deformable soft material can be obtained by making the continuous portion thin, but soft synthetic resin such as polypropylene resin or polyethylene resin may also be used directly, or a deformable metal plate can be used. , a positioning pin 10 and a lock pin 11 can also be implanted.

Further, if the positioning pin 10 is formed into a tapered shape as shown in FIG. 6, it will be easier to fit into the engagement hole 7.
Moreover, since it is press-fitted into the engagement hole 7 through the tapered surface 10a, both inner cutter bodies 1 are held even more firmly.

As described above, in the present invention, the inner cutter bodies 1, 1 in which a plurality of inner cutter blades 2 are connected in a semi-cylindrical shape are joined together with their base surfaces facing each other, and the cylindrical polished block 8 is assembled. , and when this block 8 is subjected to seretarless polishing and edged, reinforcing plates 4 are integrally provided at both ends of the inner blade body 1.
A protrusion 6 that protrudes downward from the base surface of the inner blade bodies 1, 1 is formed in the center of the inner blade body 1,
In the engagement hole 7 of the block 8, the engagement hole 7 of the block 8 is formed, and the engagement hole 7 of each protrusion 6 is aligned so that the base surfaces thereof face each other. This engagement hole 7
Pin 1 for positioning the assembly jig 9 formed corresponding to
0 is penetrated to determine the perfect circular position, the above-mentioned selectorless polishing is performed, and the engagement hole 7 of the reinforcing plate 4 is aligned with the inner blade 1.
is located at the axial center P position, and this engagement hole 7 is located at the inner blade body 1.
By regulating the position of this hole 7 with the assembly jig 9, the perfect circle position of the inner cutter body 1 is regulated at both ends in the length direction, so the perfect circle position is determined over the entire length. , it is possible to properly perform centerless polishing with highly accurate roundness, and it is possible to improve the polishing accuracy and workability of the cutting edge portion.

In addition, since the engagement hole 7 that determines the roundness only needs to be placed in one place, unlike the conventional multiple holes, the dimensional control of production jigs and tools such as manufacturing molds for the reinforcing plate 4 is simplified, and the results are improved. Dimensions and quality control of the raised inner cutter body 1 can also be easily controlled.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an inner blade body and an assembly jig applied to the reciprocating electric shaver polishing method according to the present invention;
Figure 2 is an explanatory diagram of the reinforcing plate, Figure 3 is a front view showing the inner blade body in a hugged state, Figure 4 is a side view of Figure 3, and Figure 5 is the assembly jig attached. A partially broken front view showing a cylindrical block to be polished; FIG. 6 is a sectional view showing a modification of the assembly jig;
FIG. 7 is an exploded perspective view showing the inner blade body and assembly jig of the conventional example;
FIG. 8 is a front view showing a state in which the inner blade bodies of the conventional example are tied together. 71... Inner blade body, 2... Inner cutter blade, 3... Connecting member, 4... Reinforcement plate, 6... Protrusion part, 7... Engagement hole part, 8... - Cylindrical block to be polished, 9... Assembly jig, 10... Positioning pin, 11... Lock pin, P... Axis center.

Claims (1)

[Claims] 1 Inner blade body 1 in which a plurality of inner cutter blades 2 are connected in a semi-cylindrical shape
. Inner blade body 1,
A protrusion 6 is formed that protrudes downward from the base surface of the inner blade 1, and an engagement hole 7 is formed in the protrusion 6 so that the inner blade 1 is positioned at the axis P.
The blocks 8 are arranged so that the base surfaces thereof face each other and the engagement holes 7 of the respective protrusions 6 are aligned with each other.
The positioning pin 10 of the assembly jig 9 formed corresponding to the engagement hole 7 is passed through the engagement hole 7 to determine the perfect circular position, and then the centerless polishing is performed as described above. A method of polishing the inner blade of a reciprocating electric razor.