JPH0214753Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a reciprocating electric shaver equipped with means for detecting motor rotational speed.

[Conventional technology]

In this type of electric shaver, for example, the motor rotation speed is controlled so as to provide stable sharpness regardless of the weight of the load, but for this purpose a means for detecting the motor rotation speed is required.
In addition, in a rechargeable electric shaver, it is desirable to detect the rotational speed of the motor and, when the speed decreases, use an indicator lamp to notify the need for charging. need to be detected.

When detecting the rotational speed of a small motor used in such an electric shaver, it is necessary to avoid power loss due to this detection, and a non-contact type detection means is desirable.

Therefore, the present inventor investigated a rotational speed detection means using a photo interrupter. For example, a photo sensor is created in which a rotating body to be detected, which has a black area at a constant circumferential pitch on its outer circumferential surface, is attached to the motor output shaft, and a light emitting part and a light receiving part are aligned and integrated facing the outer circumferential surface of the rotating body. This is a means for obtaining the rotational speed based on the pulsed output from the light receiving section by providing an interrupter.

[Problem that the invention attempts to solve]

However, with the detection means considered earlier, if the electric shaver is of the type where the inner cutter vibrates back and forth with respect to the outer cutter, the vibrator is activated by driving an eccentric cam etc. with the motor output shaft. Therefore, larger vibrations are generated than in the rotary type, and in particular, the photo interrupter tends to vibrate slightly in the direction of vibration due to the vibration of the inner cutter, and this vibration tends to cause the above-mentioned erroneous detection to occur significantly.

This invention aims to eliminate such problems.

[Means for solving problems]

In order to achieve the above object, in the present invention, as shown in FIG. It is assumed that the motor rotation speed detecting means is composed of a rotating body 24 to be detected rotated by the drive of the motor 4 and a photo interrupter 26 disposed opposite thereto. The imaginary line A connecting the light receiving portion 26a and the light receiving portion 26b is arranged so as to coincide with the direction perpendicular to the vibration direction B of the inner cutter 13.

[Effect]

In this case, even if the photo interrupter 26 slightly vibrates in the direction of vibration due to the vibration of the inner cutter 13, detection errors in the motor rotation speed will not occur. This is, for example, Fig. 5a,
As shown in b, an imaginary line A connecting the light emitting part 26a and the light receiving part 26b of the photo interrupter 26
If the photo interrupter 26 is arranged parallel to the vibration direction B of the inner cutter 13, as shown in FIG. 24, the light receiving part 26b cannot reliably detect the light reflected from the light receiving part 24, resulting in a detection error. If the direction is set, photo interrupter 2
Even if some slight vibration occurs in the vibration direction B, detection errors will not occur.

[Effect of idea]

Therefore, according to the present invention, it has become possible to accurately detect the motor rotational speed with a relatively simple modification of changing the directional arrangement of the light emitting section 26a and the light receiving section 26b of the photo interrupter 26.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

In Figures 1 to 3, the main body case 1 of this electric shaver includes a front case 1a and a rear case 1b.
A double-shaft type motor 4 with output shafts 2, 2 protruding from both upper and lower ends is installed at the upper part of the main body case 1 via a mounting base 5. Rechargeable batteries 6 are provided on both left and right sides of the motor 4. Corresponding to the lower position of the motor 4, the rotation speed detection board 7 is located deep inside the case where it is not affected by external light or hair debris.
A charging block board 8 equipped with the battery 6 and the like are arranged in front and behind the output shaft 2 at the lower end of the motor 4.

A reciprocating vibration type razor unit 9 is provided in the upper part of the main body case 1. This razor unit 9 is constructed so that a large number of groups of inner cutters 13 arranged in parallel on an inner cutter holder 12 are reciprocated from side to side against the inner surface of a mesh-like outer cutter 11 supported by an outer cutter holder 10. The inner blade holder 12 is connected to the upper support shaft 1 of the vibrator 14 installed inside the upper end of the main body case 1.
5 via a vertically movable sleeve 16 and a swingable bracket 17.

Thin legs 1 are provided at both left and right ends of the vibrator 14.
9 and 19 are provided, and the upper ends of these legs 19 and 19 are provided with engagement recesses 20 and 20 formed at the upper end of the main body case 1,
20, and elastic deformation of these legs 19, 19 causes the vibrator 14 to move left and right approximately in parallel as a whole. The vibrator 14 is engaged with an upper eccentric pin 22 of a balancer 21 attached to the output shaft 2 at the upper end of the motor 4, and is reciprocated left and right with a constant stroke as the motor 4 rotates.

The output shaft 2 on the lower end side of the motor 4 has a roll-shaped rotating body to be detected, which has black parts 23a in the form of elongated axial bands and white parts 23b alternately attached at a constant pitch in the circumferential direction on its outer peripheral surface. 24, a photo interrupter 26 is installed on the rotation speed detection board 7 so as to face the rotating body 24 to be detected.
At this time, the photo interrupter 26 is the light emitting part 26a.
The inner cutter 13 is arranged so that an imaginary line A connecting the inner cutter 13 and the light receiving portion 26b is perpendicular to the vibration direction B of the inner cutter 13. This photo interrupter 26 irradiates the circumferential surface of the rotating body 24 to be detected with light emitted from the light emitting part 26a,
The photointerrupter 26 is configured to receive and sense the reflected light with the light receiving section 26b.
A control circuit that detects the motor rotation speed based on a pulsed detection signal taken out from the substrate, controls the voltage applied to the motor 4 based on this, and maintains the motor rotation speed within a predetermined range. It is assembled into 7.

As mentioned above, the rotation speed detection board 7 and the charging block board 8 are placed opposite each other in the front and back across the rotating body 24 to be detected on the output shaft 2 of the motor 4, but the boards 7 and 8 themselves are The rotation speed detection board 7, which is both made of a plastic plate and is equipped with a photo interrupter 26, is constructed to be lighter than the charging block board 8, which is heavy due to the heavy objects such as a rechargeable battery 6 and a transformer. . Even if the electric shaver is accidentally dropped, the rotational speed detection board 7 on the lighter side will not be misaligned as much as the charging block board 8 on the heavier side due to the impact, and the photo interrupter 26
This means that the positional displacement of the object with respect to the rotating body 24 to be detected can be suppressed as much as possible.

The charging block board 8 is positioned and fixed on the inner surface of the rear case 1b.

The rotation speed detection board 7 is positioned so that a photo interrupter 26 attached thereto faces the rotating body 24 to be detected at a constant interval. This positioning means includes a plug terminal plate 28 having a charging plug blade 27 and a charging plug receiver 29.
is used. Specifically, the charging plug holder 29
is fitted and fixed to the bottom wall side of the main body case 1 so as to be interposed between both lower ends of the charging block board 8 and the rotation speed detection board 7. On the upper surface of the charging plug receiver 29, a plug terminal board 28 having a charging plug blade 27 protruding from the lower surface side is placed with the charging plug blade 27 inserted into the upper surface of the plug receiver 29. The front and rear ends of the plug terminal plate 28 are inserted into slits 7a and 8a provided at the bottom of the charging block board 8 and the rotation speed detection board 7, respectively, and are connected to the front case a and the rear case 1b.
is engaged on each inner surface of the. Also, the rotation speed detection board 7
Notches 7b, 7b are provided on the left and right sides of the upper edge, and two left and right columns 30, 30 are provided protruding from below the motor 4 on the inner surface of the rear case 1b, and a step is provided at the tip of each of the columns 30, 30. The notch 7b is engaged with the attached tip portion 30a. Thus, the rotation speed detection board 7
is restricted from moving vertically and horizontally by the plug terminal plate 28 and the support post 30, and movement in the front and rear direction is restricted by the charging plug receptacle 29 and the support post 30. In particular, by restricting the movement of the rotation speed detection board 7 in the front-rear direction, the distance between the photo interrupter 26 and the rotating body 24 to be detected is kept constant. Note that in order to more reliably restrict movement in the horizontal and vertical directions on the lower end side of the rotation speed detection board 7, a notch 31 is provided at the lower edge of the rotation speed detection board 7, and a cutout 31 is provided at the lower edge of the rotation speed detection board 7. A protrusion 32 may be provided on the side surface of the charging plug receptacle 29 with which the notch 31 is engaged.

[Another example]

In the above embodiment, the motor 4 is connected to the inside of the main body case 1.
The motor 4 is arranged in a vertical position with the output shafts 2, 2 facing up and down, but instead of this, the motor 4 is arranged in a horizontal position with the output shafts 2, 2 facing left and right as shown in FIG. The output shaft 2 on the right end side is used as a drive shaft for the inner cutter 13 via a transmission mechanism 33 including a cam, a link mechanism, etc., and the rotating body 24 for detection is attached to the output shaft 2 on the left end side. The photo interrupter 26 is arranged so that the virtual line A connecting the light emitting part 26a and the light receiving part 26b is perpendicular to the vibration direction B of the inner cutter 13, just as in the above embodiment.

[Another example]

As in each of the above embodiments, a double shaft type motor 4 with output shafts 2, 2 protruding from both ends is used as the motor 4 for driving the inner cutter, and the output shaft 2 at one end is used to drive the inner cutter.
3 and a photo interrupter 26 is attached to the output shaft 2 on the other end side, there is a problem that the rotating body 24 to be detected receives vibration from the inner cutter 13 and shifts its position, causing a detection error. This is advantageous in that it can be avoided as much as possible. However, the present invention is not limited to this, and uses a general motor 4 having an output shaft 2 only at one end thereof.
may be used to drive the inner blade, and the rotating body 24 for detection may be mounted on the same shaft 2.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an electric shaver showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional side view, and FIG. 3 is an exploded perspective view of the main parts. FIG. 4 is a schematic front view of main parts showing another embodiment of the present invention. Figure 5a,
b and c show comparative examples with the photo interrupter according to the present invention, and Fig. 5 a is a front view thereof;
FIG. 5b is a plan view, and FIG. 5c is a plan view showing a defective state in which the position has shifted. 1...Main body case, 2...Output shaft, 4...Motor, 13...Inner blade, 24...Rotating body for detection, 2
6... Photo interrupter, 26a... Light emitting part,
26b... Light receiving section.

Claims (1)

[Claims for Utility Model Registration] (1) The main body case 1 is provided with a motor 4, an inner cutter 13 that vibrates back and forth by the motor 4, and a rotational speed detection means for the motor 4, and the motor rotational speed detection means is It is composed of a rotating body 24 to be detected rotated by the drive of a motor 4 and a photo interrupter 26 disposed opposite thereto. A reciprocating electric shaver characterized by being arranged so as to coincide with a direction perpendicular to direction B. (2) The rotating body 24 to be detected has a black part 23 on the outer peripheral surface.
The reciprocating electric shaver according to claim 1, which is constituted by a roller in which white portions 23a and 23b are alternately formed at a constant pitch in the circumferential direction.