JPH049436B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inner cutter for a reciprocating electric shaver in which a large number of inner cutter blades are arranged in a row.

[Background Art] As shown in FIGS. 4 and 5, a reciprocating electric shaver has a blade composed of an outer cutter 5 and an inner cutter A that slides into contact with the inner surface of the outer cutter 5 by being reciprocated. Furthermore, the inner cutter A is constructed by connecting a large number of inner cutter blades 2 with reinforcing ribs 3 and arranging them in a row. In addition, the inner blades 2 have conventionally been formed of a stainless steel thin plate, and when the inner blades 2 are driven in combination with the outer cutter 5, the cutting edge of each inner blade 2 touches the inner surface of the outer cutter 5, as shown in FIG. They were supposed to be in close contact with each other.

By the way, the inner cutter is required to have good adhesion and wear resistance with the inner surface of the outer cutter, which affects the cutting quality, and for this reason, it is necessary to improve the adhesion by increasing the flatness and cylindricity of the inner cutter in the driving direction. Attempts have been made to increase the wear resistance of the cutting edge of the outer cutter by applying an ultra-hard thin film coating such as titanium nitride to the outer cutter, or to directly improve the wear resistance of the inner cutter blade itself. Attempts have been made to use hard ceramic solids or thin film coatings.

However, as mentioned above, the conventional inner blade configuration was such that the cutting edge of each inner blade was in close contact with the inner surface of the outer blade, so in order to improve wear resistance, ultra-hardened Even if it is possible to achieve this, there is a problem in that the cost associated with this is large and there is little merit in practical application.
Improving the adhesion with the outer cutter by making the cutting edge of each inner blade come into close contact with the inner surface of the outer cutter results in an increase in the blade sliding load.

[Objective of the Invention] The present invention has been made in view of the above points, and its objectives are to provide high wear resistance and long sharpness life, not to be very expensive, and to reduce sliding resistance. To provide an inner blade for an electric shaver that has a small load and thus has a long battery life in a battery-powered electric shaver.

[Disclosure of the Invention] The present invention provides an inner cutter for a reciprocating electric shaver in which a large number of inner cutter blades are arranged in a row. The feature is that the hardness of the inner blade, which is shorter than the cutting blade, is lower. Although the heights of the inner blades are different, this difference is only a few microns and does not particularly impair sharpness.

The present invention will be described in detail below based on the illustrated embodiment. As shown in FIG. In this case, the inner blades 1 and 2 are
consists of two types: a tall inner blade 1 and an inner blade 2 that is shorter by a slight dimension δ (about several microns), and the inner blade 1 and the inner blade 2 are alternately arranged. It is set in. In the figure, 5 is an outer cutter, 6 is a cutting hole in the outer cutter 5, and 7 is an outer cutter rib.

The tall inner blade 1 is made of super hard material.
For example, while the inner blade 2 is made of ceramics, the shorter inner blade 2 is made of a material with lower hardness than the inner blade 1, such as stainless steel metal. In addition, here, the inner blade 1
Although the inner cutter blades 2 are provided alternately, the present invention is not limited to this. For example, the inner cutter blades 2 are provided between the two inner cutter blades 1, 1. etc. However, it is possible to arrange that there are two inner cutter blades 1 within the range of the drive amplitude S of the inner cutter A, and that one or more inner cutter blades 2 exist between both the inner cutter blades 1 and 1. , is preferable in terms of preventing uneven wear of the outer cutter 5.

In any case, among the two types of inner cutter blades 1 and 2, the one that comes into close contact with the outer cutter 5 is the taller, ultra-hard inner cutter blade 1, and the inner cutter blade 2, which is lower in hardness, is in close contact with the outer cutter 5.
Since the blade is shorter than the inner blade 1, wear resistance depends on the inner blade 1, which is super hard. The load is also reduced. Also,
The cost is considerably lower than if all the inner blades were made of super hard material.

The inner cutter A as described above can be manufactured as follows. That is, as shown in FIG. 2a, first, a hard grinding wheel 10 made of hard abrasive grains such as diamond and a hard bond of metal such as copper or brass is used to temporarily grind the inner blades 1 and 2 of both types. By grinding to the same height, the flatness and cylindricity in the driving direction are increased. Thereafter, the inner blades 1 and 2 are ground by an elastic grindstone 11 with a straight surface made of hard abrasive grains such as diamond or boron nitride with plastic or rubber bond. At this time, if the cutting amount of the elastic grinding wheel 11 into the inner cutting blades 1 and 2 is constant, even if the cutting amount of the elastic grinding wheel 11 is the same for both types of inner cutting blades 1 and 2, the cutting amount for the ultra-hard inner cutting blade 1 Since the amount of machining for the stainless steel inner blade 2 is slightly larger, the height of the inner blades 1 and 2 for both types is slightly larger as shown in Fig. 2b. It is considered to be different. This eliminates the need for difficult and costly dressing, which requires extremely high precision, such as using a grindstone with irregularities on its surface corresponding to the height of the inner blades 1 and 2. This means that the inner cutter according to the present invention can be provided at low cost. Furthermore, the third
The figure shows the state in which the two types of grinding described above are performed using a centerless grinding method. In the figure, 12 is an adjustment wheel, and 13 is a support blade. Two inner cutters A are used as a set, and grinding is performed while the outer shape is cylindrical.

[Effects of the Invention] As described above, in the present invention, the inner cutter blade is composed of multiple types of different heights, and the hardness of the shorter inner cutter blade is lower than that of the tall inner cutter blade. The tall inner blade, which determines wear resistance, is hardened, so it not only maintains good sharpness over a long period of time, but also
The hardness of the short inner blade, which does not significantly affect the wear resistance, can be provided at a lower cost than when all the inner blades are made of high hardness. Furthermore, since the sliding load is reduced, the battery life of battery-powered products is extended.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, Fig. 2 a and b are longitudinal cross-sectional views showing the grinding process in manufacturing the same, Fig. 3 is a front view of the grinding process, Fig. 4 5 is a cross-sectional view showing the general structure of a reciprocating electric shaver, FIG. 5 is a perspective view of the same outer cutter and inner cutter, and FIG. 6 is a longitudinal cross-sectional view of a conventional example, in which A is the inner cutter; ,2
indicates an inner blade.

Claims (1)

[Claims] 1. In the inner blade of a reciprocating electric shaver in which a large number of inner blades are arranged in a row, the inner blades are composed of multiple types of inner blades with different heights, and the inner blades with a shorter height are made smaller than the tall inner blades. An inner blade of a reciprocating electric shaver characterized by having low hardness.