JPS6222677A - Reciprocal drive type electric razor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a reciprocating electric shaver.

[Background technology]

A reciprocating electric shaver that shaves by reciprocally driving the inner blade is equipped with a plate-shaped piezoelectric actuator that vibrates when voltage is applied, and the vibration of the piezoelectric actuator is used to drive the inner blade reciprocally. is configured to do so.

An example of a device equipped with such a piezoelectric actuator is disclosed in Japanese Patent Publication No. 51-6585.

In the device disclosed in the above publication, voltage is directly applied to the piezoelectric actuator using a commercial frequency power source. As a result, the inner cutter connected to the piezoelectric actuator only vibrates at a commercial frequency of 50 to 60 Hz, and as a result, the inner cutter has poor cutting performance, resulting in problems such as hair pulling.

[Purpose of the invention]

This invention has been made in order to solve the above problem, and aims to improve sharpness. [Disclosure of the Invention] In order to achieve the above object, this invention provides a piezoelectric actuator that vibrates when a voltage is applied. The gist of the present invention is a reciprocating electric shaver characterized by having a frequency conversion circuit connected to the piezoelectric actuator and converting the frequency of the piezoelectric actuator to a higher frequency.

Hereinafter, one embodiment of this invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a device body, and an outer cutter mount 2 is attached to the outer periphery of the -L end of the device body.

An outer cutter 3 is attached to an opening formed in the upper part of the outer cutter mount 2. This outer cutter 3 has a large number of whisker introduction holes (not shown) formed therein. Reference numeral 4 denotes an inner cutter, which is provided inside the outer cutter 3 so as to be able to slide back and forth, and its direction is left and right in FIG.

On the other hand, the structure for reciprocally driving the inner cutter 4 is as follows.

In other words, as shown in detail in Fig. 2(a) and Fig. 2 fb), numeral 5 is an actuator mounting piece, and a pair of actuator mounting pieces 5 are fixed in the device body 1. A pair of piezoelectric actuators 6 (1 & H) are fixed at their lower ends by press-fitting or the like. The piezoelectric actuators 6 each have a plate shape, protrude upward, and are arranged parallel to each other. 7 is a support shaft, which is also fixed to the device body 1;
A vibration transmitter 9 is supported by a rotary support boss 8 fitted onto the support shaft 7 . The vibration transmitting body 9 includes a rotary vibration part 10 having a rotary support boss 8 in the middle part,
It has a linear vibrating part 11 arranged horizontally below the vibrating part 10, and a flexible joint part 12 in a constricted shape is provided between both the vibrating parts 10 and 11 to provide flexibility. Both shoulder parts 13.13 of the linear drive part 11 are press-fitted and connected to the upper end of each piezoelectric actuator 6, while the rotary vibration part 1
The upper end of the blade 0 is connected to the inner cutter 4 shown in FIG.

The piezoelectric actuator 6 moves as shown in FIG. 3 by applying a voltage.
When it is vibrated reciprocatingly in the direction, the linear vibrating part 11 connected thereto is also driven and vibrated in the direction of arrow It rotates in the Y direction and vibrates reciprocally. This causes the inner cutter 4 (FIG. 1) to vibrate.

This reciprocating electric shaver is provided with a frequency conversion circuit 14 as shown in FIG. 1 in order to convert a commercial frequency power source to a frequency higher than the commercial frequency.

Here, the details are shown in FIG. 2 (al). In other words, 15 is a commercial frequency power source whose frequency is 50 to 60 Hz, and 16 is an equipment switch,
A rectifier block 17 for converting alternating current into direct current is provided on the circuit including the commercial frequency power supply 15 and equipment switch 16, and the voltage is maintained constant through the rectifier block 17, and a smoothing filter 18 for smoothing the direct current. A constant voltage circuit 19 is provided. 20 is the inverter section,
It oscillates direct current at 130H2 and converts it into alternating current, and 21 is a sine wave filter that shapes the waveform into a sine wave.

A frequency conversion circuit 14 is thus configured and connected to each piezoelectric actuator 6.

According to the frequency conversion circuit 14, the current from the commercial frequency power source 15 is converted into direct current by the rectifier block 17 and the smoothing filter 18 by the input operation of the equipment switch 16, and then controlled to a constant voltage by the constant voltage circuit 19. after,
The inverter unit 20 oscillates the signal at 130 Hz, and the sine wave filter 21 shapes the signal into a sine wave. In this way, a voltage having a frequency of 13011z is applied to the piezoelectric actuator 6.

In the reciprocating electric shaver according to the present invention, the frequency of the commercial frequency power source 15 (50 to 6
011z) becomes 130tlz and is applied to the piezoelectric actuator 6, so the inner cutter 4 (Fig. 1)
The razor also vibrates faster due to its higher frequency, achieving the desired cutting speed for this type of razor, allowing for more effective and sharp treatment of beards.

Note that the frequency increase/decrease range can be changed by the variable resistor 22, and therefore, the variable resistor 22
By operating the piezoelectric actuator ≠ the output displacement of the unitaro changes, the amplitude of the inner cutter 4 (Fig. 1) also changes. For example, when shaving a long beard, increase the amplitude of the inner cutter 4 and shave it short. When finishing, the amplitude of the inner cutter 4 is reduced, allowing for effective shaving according to the characteristics of each beard. -The lower limit of the above frequency is 90Hz and the upper limit is 15Hz.
It is preferable to set it to 0Hz. In other words, if the frequency is lower than 90Hz, the effect of improving sharpness, which is the original purpose of this invention, will be reduced, while if it exceeds 150Hz, vibration noise will become excessive.
There is a risk of quality deterioration.

In the embodiment described above, the constant voltage circuit 19 is provided, but in this case, the applied voltage is kept constant, so the fluctuation rate of the displacement of the piezoelectric actuator 6 is suppressed to a small level.
By making the amplitude of the inner cutter 4 (FIG. 1) constant, stabilization of cutting quality can be ensured.

In the above embodiment, the resonance frequency of the vibration system between the piezoelectric actuator 6 and the inner cutter 4, that is, the vibration system including the piezoelectric actuator 6, the vibration transmitter 9, and the inner cutter 4, and the frequency applied to the piezoelectric actuator 6 are By causing the blades to defeat each other, the amplitude of the inner cutter 4 increases, and a vibration system with good sharpness and efficiency can be obtained.

Here, - the resonant frequency f0 of the inner cutter obtained with the vibration system of the above embodiment is shown in Fig. 4 (al and its model diagram).
Consider based on Figure fbl. Figure 4 (in al.
G indicates the position of the center of gravity of the entire body including the inner cutter 4 and the rotating vibration part]0, and in FIG.
and the mass including the rotary vibrating part 10, m is the rotary vibrating part 10
The mass of the vibration transmitting body 9 excluding . Furthermore, Fig. 4 Te
In (b), l is the dimension between the center of gravity position G and the center of the support shaft 7, and 7!2 is the dimension from the center of the support shaft 7 to the linear vibrating part 11. K indicates a spring constant for four piezoelectric actuators 6.

Then, the resonant frequency is expressed by the following equation.

This resonance frequency f0 may be made to match the frequency applied to the piezoelectric actuator 6.

At the same time, in order to obtain a large amplitude of the inner cutter 4, the following configuration can be adopted.

That is, in FIG. 4 ta+, I21 indicates the center-to-center dimension between the connecting pin 23 between the inner cutter 4 and the vibration transmitting body 9 and the support shaft 7, and this j2. However, the above 12 is shortened (and
The ratio relationship is set such that J+/Rz>1.

Based on such a ratio relationship, the amplitude of the inner cutter 4 is amplified, leading to improved sharpness.

In this case, as shown in FIG. 5, the flexible joint section 12 may be formed as a pair of left and right elastic thin plates, or as shown in FIG. This ball joint 24
If it is fitted into the joint receiver 25 provided at the center of the linear vibrating part 11, vertical displacement can be effectively absorbed and the amplitude of the inner cutter 4 can be further increased.
This makes it possible to obtain satisfactory sharpness.

Here, if the connection between the piezoelectric actuators 6 located on the outside and the vibration transmitting body 9 is made by a loose fitting structure that allows relative vertical sliding, the resistance can be further reduced and the amplitude can be increased. advantageous to

On the other hand, in the above example, a commercial frequency power source is used, but as shown in FIG. 2(C), a battery 2
6, as a frequency conversion circuit, for example,
A booster circuit 27, an inverter section 20, and a sine wave filter 21 are configured.

〔Effect of the invention〕

As explained above, according to the present invention, a frequency conversion circuit that converts the power supply frequency to a higher frequency is provided, so the vibration of the inner blade is higher than when the power supply frequency is directly applied. This improves the sharpness of the inner blade.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a reciprocating electric shaver showing an embodiment of the present invention, FIG. 2 +a+ is a system diagram showing a vibration system and a frequency conversion circuit, and FIG. Figure 2 (C1 is a circuit block diagram of the frequency conversion circuit when using a battery, Figure 3 is an explanatory diagram of the operation of the vibration system, and Figure 4 fa) is a front view of the vibration system to explain the resonant frequency. ,
FIG. 4fbl is a vibration model diagram thereof, FIG. 5 is a front view of a vibration system for increasing the amplitude of the inner cutter, and FIG. 6 is a front view of a vibration system showing another embodiment. 4...Inner blade 6...Piezoelectric actuator 14...
・Frequency conversion circuit agent Takehiko Matsumoto, patent attorney Figure 4 (a) Figure 5

Claims (6)

[Claims] (1) In a reciprocating electric shaver comprising a piezoelectric actuator that vibrates when a voltage is applied and an inner blade that is connected to the piezoelectric actuator and is driven reciprocally by the vibration of the piezoelectric actuator, the power supply frequency is set to a higher frequency than that of the piezoelectric actuator. A reciprocating electric shaver characterized by having a frequency conversion circuit that converts the frequency to (2) A reciprocating electric shaver according to claim 1, wherein the piezoelectric actuator is plate-shaped. (3) The reciprocating electric shaver according to claim 1 or 2, wherein means for varying the amplitude of the inner cutter is provided on the circuit between the power source and the piezoelectric actuator. (4) The reciprocating electric shaver according to claim 3, wherein the means for varying the amplitude of the inner cutter is a variable resistor. (5) Claims 1 to 4, wherein the frequency conversion circuit is equipped with a constant voltage circuit that controls the voltage to be constant.
The reciprocating electric shaver described in any of the preceding paragraphs. (6) Any one of claims 1 to 5, wherein the resonant frequency of the vibration system composed of the piezoelectric actuator and the inner blade is substantially the same as the frequency after conversion by the frequency conversion circuit. The reciprocating electric shaver described in .