JPH049438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a drive mechanism for a reciprocating electric shaver.

[Background Art] A reciprocating electric shaver that shaves by reciprocally driving inner blades is equipped with a plate-shaped piezoelectric actuator that bends and vibrates when an alternating current voltage is applied. The inner cutter is configured to reciprocate using the vibrations of the inner cutter. A drive mechanism equipped with such a piezoelectric actuator is disclosed in Japanese Patent Publication No. 53-6586.

The piezoelectric actuators in the above publication are each one
The blade is fixed at its lower end and connected to the inner cutter at its upper end, constituting only one stage of vibration system. In such a drive mechanism, for example, when a voltage of 100 VAC is applied to a commonly used piezoelectric actuator with a length of 35 mm, width of 16 mm, and plate thickness of 0.5 mm, only a small inner blade amplitude of about 1.0 mm can be obtained. Considering the blade pitch of the inner cutter, the amplitude described above does not provide sufficient sharpness.
Therefore, for example, it may be possible to make the piezoelectric actuator sufficiently long, but this would increase the amplitude and ensure sufficient sharpness, but it would be too long and would prevent the device from being made more compact. There is an inconvenience.

[Purpose of the invention]

In view of the above problems, an object of the present invention is to provide a drive mechanism for a piezoelectric actuator that can improve sharpness and make the device more compact.

[Disclosure of the Invention] In order to achieve the above object, the present invention provides an electric shaver in which an inner cutter is driven reciprocally with respect to an outer cutter, in which a first piezoelectric actuator and a second piezoelectric actuator are arranged in the reciprocating direction of the inner cutter. The first actuator is arranged side by side so as to bend and vibrate in synchronization in the same direction.
One end of the piezoelectric actuator is fixed to the equipment body, and the same end of a second piezoelectric actuator is connected to the inner blade directly or via a driver, and the other end of the same side of both piezoelectric actuators is connected to the inner blade to reciprocate. The gist of the present invention is a reciprocating electric shaver characterized in that the electric shaver is connected to vibration amplifying transmission pieces provided parallel to the direction of movement.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments.

In FIGS. 1 and 2, an outer cutter mount 2 is attached to the outer periphery of the upper end of the equipment body 1, and an outer cutter 3 is attached to the opening formed in the upper part of the outer cutter mount 2. It is being This outer blade 3
A large number of whisker introduction holes (not shown) are formed in the. The inner cutter 4 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.

The mechanism for driving this inner cutter 4 is constructed as follows. Note that the direction in the following explanation is the first direction.
Based on the diagram. Inside the upper side of the device body 1,
A pair of leg mounting pieces 5, 5 that face each other in the reciprocating direction of the inner cutter 4 are fixed, and these leg mounting pieces 5, 5 are arranged symmetrically with respect to the longitudinal center of the device body 1 in the width direction. ing. Mounting protrusions 7 formed protruding from both sides of the lower end of the driver 6 are press-fitted and fixed into the leg mounting pieces 5, 5.
The drive element 6 is formed into a U-shape by a connecting rod 8 whose longitudinal direction is oriented in the direction in which the inner cutter 4 reciprocates, and a pair of left and right elastic legs 9, 9 projecting downward from both ends of the connecting rod 8. Frame-shaped part (hereinafter referred to as U-shaped frame)
The main part is integrally equipped with a driving rod 10 projecting upward from the upper center thereof. The elastic legs 9 are formed in a thin plate shape so as to be able to vibrate in the direction in which the inner cutter 4 reciprocates using each leg attachment piece 5 as a fulcrum. Further, the upper end of the drive rod 10 is connected to the inner cutter 4, and the neck portion 11 in the middle thereof is
It is supported at the center of an elastic support plate 13 provided in the upper end opening 12 of the device body 1 . A shaft support piece 14 is fixed to the inner wall surface of the device body 1 at a position near the upper corner of the space inside the U-shaped frame of the drive element 6, and a shaft support pin protruding from the shaft support piece 14 is fixed to the inner wall surface of the device body 1. Support arm 16 via 15
is rotatably attached. This support arm 16 is arranged in parallel near the lower side of the connecting rod 8. A horizontal vibration amplification transmission piece 17 parallel to the connection rod 8 is disposed on the lower opening side of the U-shaped frame of the driver 6, and one side of this vibration amplification transmission piece 17 and the support arm 16 A pair of parallel elastic legs 18, 18 are integrally connected between the other side of the amplitude amplification transmission piece 17 and the connecting rod 8.
Another pair of elastic legs 19, 19 are also connected in parallel and integrally to one side of the elastic legs 19, 19. The vibration amplification transmission piece 17 is supported by each of these elastic legs 9, 18, 19 so as to be able to vibrate reciprocatingly in a substantially horizontal direction. The piezoelectric actuators 20 and 21 each include a set of three plate pieces that bend and vibrate when an alternating current voltage is applied by utilizing the electrostrictive effect of laminated ceramic plates, and the plate pieces are arranged parallel to each other. It is what it is. One set of three cards
The piezoelectric actuator 20 has an upper end that is a fixed end that passes through the support arm 16 and is slidably supported thereon, while a lower end that is a vibration end that is slidable on one side of the vibration amplification transmission piece 17. Connected for free movement. Another assembled second piezoelectric actuator 2
1 is a vibration amplification transmission piece 17 whose lower end is a fixed end.
It is slidably connected to the other side, and the upper end, which is the vibrating end, is also slidably connected to one side of the connecting rod 8. First and second piezoelectric actuator 2
0 and 21 are thus arranged in parallel within the U-shaped frame body, and the parallel direction is parallel to both elastic legs 9 and 9.
The directions are opposite to each other, that is, the left and right directions. The first piezoelectric actuator 20 is wired so that a voltage from an AC power source 22 is applied thereto, and the first and second piezoelectric actuators 2
0 and 21 are electrically connected by conductive connectors 23 and 24 embedded and fixed in the vibration amplification transmission piece 17. That is, each connector 23, 24
is adapted to contact each electrode of the first and second piezoelectric actuators 20 and 21.

The drive mechanism includes a first piezoelectric actuator 20 in the first stage, a vibration amplification transmission piece 17 that vibrates by the actuator 20, and the transmission piece 1.
7 as a reference, the first piezoelectric actuator 20 vibrates and amplifies the vibration when an AC voltage is applied, as shown in FIG. At the same time as the transmission piece 17 for vibration amplification vibrates, the second piezoelectric actuator 21 also bends and vibrates at the same time with reference to the transmission piece 17 for vibration amplification.
The displacements (amplitudes) of 0 and 21 are added and appear on the driver 6, and as a result, the inner cutter 4 vibrates with a large amount of displacement, resulting in good cutting quality. If the piezoelectric actuators 20 and 21 are arranged in parallel in the direction of vibration as in the embodiment described above, they can be arranged in an effective space within the U-shaped frame of the driver 6. It is possible to achieve compactness.

In addition, in the embodiment, the second piezoelectric actuator 2
1 is connected to the inner cutter 4 via the drive element 6, but it may be directly connected to the inner cutter without using the drive element. Further, one end of the first piezoelectric actuator 20 may be directly fixed to the device body without using the support arm 16 which is pivotally attached at one end.

〔Effect of the invention〕

As described above, this invention includes a plurality of piezoelectric actuators and adds the bending vibrations of these through the vibration amplification transmission piece, thereby reducing the reciprocating motion of the inner cutter while avoiding an increase in overall size. Displacement can be increased, and sharpness can be improved.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of a reciprocating electric shaver showing an embodiment of the present invention, Fig. 2a is an enlarged view showing the drive mechanism of Fig. 1, and Fig. 2b is
3 is a side view of the drive element, and FIG. 3 is a sectional view showing the operating state of the drive mechanism. 4... Inner blade, 6... Drive element, 20, 21... Piezoelectric actuator.

Claims (1)

[Scope of Claims] 1. An electric shaver in which an inner cutter is reciprocatingly driven relative to an outer cutter, in which a first
A piezoelectric actuator and a second piezoelectric actuator are arranged side by side so as to bend and vibrate synchronously in the same direction, one end of the first piezoelectric actuator is fixed to the equipment body, and the same end of the second piezoelectric actuator is fixed to the device body directly or The piezoelectric actuator is connected to the inner cutter via a driver, and the other ends of the piezoelectric actuators on the same side are respectively connected to vibration amplification transmission pieces that are provided so as to be able to reciprocate in the reciprocating direction of the inner cutter. A reciprocating electric razor. 2. The reciprocating electric shaver according to claim 1, wherein both piezoelectric actuators are each composed of a combination of a plurality of plate-like pieces arranged parallel to each other. 3. The drive element includes a U-shaped frame body having a connecting rod arranged to be able to reciprocate in the reciprocating direction of the inner cutter and elastic legs protruding in the same direction from both ends of the connecting rod, and both piezoelectric actuators The reciprocating electric shaver according to claim 1 or 2, wherein the legs are arranged in the U-shaped frame body in parallel in opposite directions.