JP4460919B2 - electric toothbrush - Google Patents

Description

  The present invention relates to an electric toothbrush.

As an example of a conventional electric toothbrush, the rotational movement of the eccentric cam attached to the rotation shaft of the face gear that meshes with the pinion of the drive motor is transmitted to the cam follower, and this cam follower reciprocates linearly and adheres to this cam follower. It is known that the driven shaft is reciprocated linearly in conjunction with the cam follower, and the brush body at the tip of the neck portion is reciprocated linearly or rotated to brush the teeth (for example, , See Patent Document 1).
JP 2002-191626 A (FIG. 1)

  The cam follower and the drive shaft fixed to the cam follower may rotate when the reciprocating linear motion is performed. Therefore, the movement of the brush body may become unstable. It is necessary to regulate dynamic movement. In order to restrict the movement of the cam follower and the drive shaft in the rotational direction, the cam follower is inserted between the face gear and the shaft support portion of the rotation shaft of the face gear formed on the case, or a protrusion is formed on the case. Then, a cam follower was sandwiched between the protrusion and the face gear.

  However, even if the rotational movement of the cam follower and the drive shaft is restricted in this way, a gap is generated between the case and the cam follower due to the movement (runaway) of the rotational direction of the cam follower and the drive shaft. In this case, the cam follower rotates and vibrates, hits the case, and generates noise. Since the electric toothbrush is used near the ear, the noise becomes unpleasant.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric toothbrush that can restrict the rotational movement of the cam follower and the drive shaft and reduce the generation of noise.

In order to achieve the above object, an electric toothbrush according to the first aspect of the present invention provides:
A gear rotatably attached to a rotating shaft and rotated by a drive motor;
An eccentric cam formed integrally with the gear by shifting the rotation shaft and the center ;
A cam follower having an elliptical hole, the inner peripheral surface of which is slidably contacted with the eccentric cam, and reciprocates according to the rotation of the gear ;
A drive shaft fixed to the cam follower and reciprocatingly moving the brush body ;
A case in which the rotating shaft is supported;
An electric toothbrush having an elastic member sandwiched in a state in which the elastic force is generated between the cam follower and the casing,
The elastic member biases the cam follower in the gear direction by its elastic force .

The elastic member has a through hole through which the rotating shaft is inserted .

Further, the case includes a first case and a second case that fits into the first case.
Each of the first case and the second case has a shaft support portion that supports the rotating shaft,
The second case is fitted into the first case in a state where the through hole of the elastic member is inserted through the rotating shaft,
The elastic member is sandwiched between the shaft support portion on the side facing the cam follower and the cam follower .

  The elastic member is a plastic film.

  ADVANTAGE OF THE INVENTION According to this invention, the electric toothbrush which can reduce generation | occurrence | production of noise while restricting the rotational movement of a cam follower and a drive shaft can be provided.

  An electric toothbrush according to an embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 2 and 3, the electric toothbrush includes a case 1 and a neck portion 2. The neck portion 2 is detachably attached to the case 1.

  Case 1 includes an outer case 11 and an inner case 12. The inner case 12 is housed inside the outer case 11. The outer case 11 includes a main body case 11a and a battery cover 11b. The battery cover 11b is detachably attached to the main body case 11a, and the battery can be exchanged by attaching and detaching the battery cover 11b.

  The inner case 12 is composed of a first inner case 12a and a second inner case 12b. The second inner case 12b is fitted and attached to the first inner case 12a. The first inner case 12a includes a battery storage chamber 121a, a motor storage chamber 122a, a cam member storage chamber 123a, and a drive shaft storage chamber 124a. A battery 13 is mounted in the battery storage chamber 121a. The drive motor 14 is attached to the motor storage chamber 122a. The battery 13 is a drive power source for the drive motor 14. The second inner case 12b is provided with a switch 30. When the switch 30 is turned on and energized, the drive motor 14 is driven.

  A shaft support portion 15 is formed in the cam member storage chamber 123a. As shown in FIG. 1, the cam member storage chamber 123 a is integrated with the rotation shaft 16 that is pivotally supported by the shaft support portion 15, the face gear 17 that is rotatably attached to the rotation shaft 16, and the face gear 17. The formed eccentric cam 18, the cam follower 19 that is in sliding contact with the eccentric cam 18, and the elastic disc 20 that is an elastic member are accommodated. The second inner case 12b is also formed with a shaft support portion 21 for supporting the rotating shaft 16.

  The face gear 17 rotates with the rotation of the motor shaft 22 of the drive motor 14 by meshing with the pinion 23 press-fitted into the motor shaft 22 of the drive motor 14.

  The eccentric cam 18 is formed in a cylindrical shape. As shown in FIG. 3, an elliptical hole 19a is formed in the cam follower 19, and the eccentric cam 18 is positioned in the elliptical hole 19a. When the inner peripheral surface of the elliptical hole 19a of the cam follower 19 is in sliding contact with the rotating eccentric cam 18, the cam follower 19 performs a reciprocating linear motion in the longitudinal direction of the electric toothbrush. A drive shaft 24 is fixed to the cam follower 19. Therefore, the cam follower 19 and the drive shaft 24 integrally perform a reciprocating linear motion.

  The elastic disk 20 has a spring property and is a member for restricting the rotation of the cam follower 19 and the drive shaft 24. The elastic disk 20 is made of a plastic film, and is formed of, for example, polycarbonate. The elastic disk 20 has a hole 20a formed at the center, and the elastic disk 20 can be attached to the rotating shaft 16 by inserting the rotating shaft 16 into the hole 20a. The diameter of the elastic disk 20 is preferably larger than the major diameter of the elliptical hole 19a of the cam follower 19.

  The second inner case 12b is inserted into the first inner case 12a so that the rotary shaft 16 pivotally supported by the shaft supporting part 15 of the first inner case 12a is inserted into the shaft supporting part 21 of the second inner case 12b. By attaching, the elastic disc 20 is disposed so as to be sandwiched between the cam follower 19 and the shaft support portion 15 of the first inner case 12a. As a result, an elastic force that urges the cam follower 19 in the direction of the face gear 17 is generated in the elastic disc 20, so that the cam follower 19 is sandwiched between the elastic disc 20 on the shaft support portion 15 and the face gear 17. Thus, the rotational movement of the cam follower 19 and the drive shaft 24 is restricted.

  The drive shaft storage chamber 124a stores a drive shaft 24 fixed to the cam follower 19 and two bearings 25 that support the drive shaft 24.

  An arm 26 is provided in the neck portion 2. A connecting member 26 a for connecting the drive shaft 24 to the arm 26 is formed at one end of the arm 26. Thereby, the arm 26 also performs reciprocating linear motion via the drive shaft 24. A rotating brush body 27 is rotatably attached to the tip of the neck portion 2. A drive pin (not shown) is attached at a position eccentric from the center of the rotating brush body 27, and the other end of the arm 26 is attached to this drive pin. Thereby, the reciprocating linear motion of the arm 26 can be converted into the rotational motion of the rotating brush body 27, and tooth brushing can be performed by the rotational motion of the rotating brush body 27.

  Thus, in the electric toothbrush of the present embodiment, the cam follower 19 is arranged in the direction of the face gear 17 by arranging the elastic disc 20 between the cam follower 19 and the shaft support portion 15 of the first inner case 12a. Since it has an urging force and is sandwiched between the elastic disc 20 on the shaft support 15 and the face gear 17, the cam follower 19 and the drive shaft 24 can be rotated without overloading the cam follower 19. Can be regulated. Therefore, the rotation of the cam follower 19 and the drive shaft 24 in the rotational direction can be reduced, and noise generated when the cam follower 19 collides with the inner case 12 due to rotational vibration can be reduced. As a result, the electric toothbrush user can perform comfortable tooth brushing.

  In addition, since the elastic disk 20 has a spring property, the cam follower 19 and the drive shaft 24 can be regulated to rotate with flexibility with respect to the movement of the cam follower 19.

  Further, since the elastic disk 20 can be easily attached to the rotation shaft 16 by inserting the rotation shaft 16 into the hole 20a, the troublesomeness of screwing the elastic disk 20 or fixing it by welding. Absent.

  Further, if the rotary shaft 16 supported by the shaft support portion 15 of the first inner case 12a is inserted into the shaft support portion 21 of the second inner case 12b, the cam follower 19 is attached to the elastic disc 20 by the face gear 17. The elastic force that urges the cam follower 19 is easily generated, and the rotational movement of the cam follower 19 and the like can be easily controlled.

  The present invention has been described with reference to the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the present embodiment, the example using the rotating brush body 27 has been described, but the brush body may reciprocate linearly in the axial direction.

  Further, in the present embodiment, an example in which the case 1 is configured by the outer case 11 and the inner case 12 has been described, but the inner case 12 is not necessarily required, and a member may be accommodated inside the outer case 11.

  Further, in the present embodiment, the example in which the elastic disk 20 is disposed between the cam follower 19 and the shaft support portion 15 of the first inner case 12a has been described, but the first inner case 12a, the cam follower 19 and In order to reduce or eliminate the gap, a protrusion is formed on the first inner case 12a, and the elastic disk 20 is disposed between the protrusion of the first inner case 12a and the cam follower 19. Also good.

  In the present embodiment, the neck 2 is detachable from the case 1, but the neck 2 and the case 1 may be integrated.

  In the present embodiment, the example using the face gear 17 has been described, but a bevel gear may be used.

  In the present embodiment, an example using the elastic disk 20 has been described. However, the elastic member 20 may be an elastic member and need not be circular.

  The diameter of the elastic disk 20 is preferably larger than the long diameter of the elliptical hole 19 a of the cam follower 19, but the diameter of the elastic disk 20 falls into the elliptical hole 19 a of the cam follower 19. Any size that does not tilt is acceptable.

  In the present embodiment, the example in which the elastic disk 20, the cam follower 19, and the face gear 17 are sequentially attached to the rotary shaft 16 that is pivotally supported by the pivotal support portion 15 of the first inner case 12a has been described. You may make it attach the face gear 17, the cam follower 19, and the elastic disc 20 in order to the rotating shaft 16 pivotally supported by the shaft support part of the inner case. Then, the cam follower 19 is biased toward the elastic disc 20 in the direction of the face gear 17 by inserting the end of the rotary shaft 16 that is not pivotally supported into the shaft support portion of the other inner case and assembling the two inner cases. An elastic force may be generated.

It is an enlarged side view near the cam member of the electric toothbrush according to the embodiment of the present invention. It is a side view of the electric toothbrush which concerns on embodiment of this invention. It is a rear view of the electric toothbrush which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Neck part 14 Drive motor 16 Rotating shaft 17 Face gear 18 Eccentric cam 19 Cam follower 19a Hole 15 Shaft support part 24 Drive shaft

Claims (4)

A gear rotatably attached to a rotating shaft and rotated by a drive motor;
An eccentric cam formed integrally with the gear by shifting the rotation shaft and the center ;
A cam follower having an elliptical hole, the inner peripheral surface of which is slidably contacted with the eccentric cam, and reciprocates according to the rotation of the gear ;
A drive shaft fixed to the cam follower and reciprocatingly moving the brush body ;
A case in which the rotating shaft is supported;
An electric toothbrush having an elastic member sandwiched in a state where an elastic force is generated between the case and the cam follower ,
The electric toothbrush characterized in that the elastic member biases the cam follower in the gear direction by its elastic force . The electric toothbrush according to claim 1, wherein the elastic member has a through hole through which the rotating shaft is inserted .   The case includes a first case and a second case that fits into the first case,
  Each of the first case and the second case has a shaft support portion that supports the rotating shaft,
  The second case is fitted into the first case in a state where the through hole of the elastic member is inserted through the rotating shaft,
  The elastic member is sandwiched between the shaft support portion on the side facing the cam follower and the cam follower.
The electric toothbrush according to claim 2. The electric toothbrush according to any one of claims 1 to 3, wherein the elastic member is a plastic film.

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