JP3622303B2 - electric toothbrush - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric toothbrush that can selectively cause a toothbrush body to perform two different types of motion, in particular, an axial reciprocating motion and a reciprocating rotational motion about an axis.
[0002]
[Prior art]
Conventionally, it is known that toothbrushing with a toothbrush includes a bath brush that performs reciprocating linear motion in the axial direction and a rolling brush that reciprocates around the axis of the toothbrush. The former is on the tooth surface and the latter is Effective for interdental area. Therefore, it is preferable that the electric toothbrush can perform both the brushing and rolling, and Japanese Patent Publication No. 52-43981 discloses an axial direction for polishing the bus through the transmission mechanism. An electric toothbrush that can selectively cause the toothbrush body to perform both the reciprocating linear motion and the swinging reciprocating motion around the axis for rolling polishing is shown.
[0003]
[Problems to be solved by the invention]
As this type of transmission mechanism, an eccentric cam having two eccentric surfaces and one concentric surface is provided, and the eccentric cam moves in the axial direction. Therefore, the entire mechanism has a large diameter, and the cam follower block is When performing the reciprocating linear motion and the oscillating reciprocating motion, there is a space limitation, and when performing the above-mentioned operation within the space saving of the thin toothbrush, the oscillating angle of ± 15 ° is obtained during the oscillating reciprocating motion. There was a drawback that it could not be obtained.
[0004]
Also, when the eccentric cam is divided into two parts and the two eccentric amounts are used properly, a protrusion is provided on the inner diameter of the normal eccentric cam, and a stopper is provided on the face gear side on the inner diameter sliding surface of the face gear and the eccentric cam. However, along with the miniaturization of the mechanism, the stopper area has not been sufficiently obtained, and it has become impossible to ensure reliability with respect to external applied loads, impact loads, and the like.
[0005]
An object of the present invention is to provide an electric toothbrush having a mechanism capable of surely switching operations within a small space.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a motor, a motion conversion mechanism that selectively converts the rotation of the motor into two different motions according to the rotation direction of the motor, and an output of the motion conversion mechanism An electric toothbrush comprising a toothbrush body that operates in a concave portion in a circumferential annular portion of a face gear having an eccentric shaft on which a first eccentric cam and a second eccentric cam constituting a motion conversion mechanism are mounted The second eccentric cam is inserted into the base side of the eccentric shaft, and the first eccentric cam is attached to the eccentric shaft so as to be located outward of the second eccentric cam. Having a stopper function to fix the position of the second eccentric cam in the recess, engaging the engaging protrusion protruding from the first eccentric cam with the engaging groove recessed in the second eccentric cam; that by forming a projecting curved surface bulging outward on both sides of the engaging protrusion The operating state of the eccentric cam can be selected by switching the reciprocating linear motion and the reciprocating reciprocating motion by controlling the operating state of the eccentric cam by switching the forward / reverse direction of the motor rotation. It is possible to increase the effective contact area of the stopper portion. When the first eccentric cam and the second eccentric cam are connected by the engagement of the engagement protrusion with the engagement groove, and the second eccentric cam and the first eccentric cam co-operate. In this case, the interference between the engagement protrusion of the first eccentric cam and the engagement groove of the second eccentric cam can be prevented, and smooth operation switching can be performed without resistance.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described. An electric toothbrush in the illustrated example is a toothbrush body that is detachably connected to a main body 1 formed in an elongated cylindrical shape and a drive shaft 2 protruding from the tip of the main body 1. In the main body 1, the motor 3, a motion for selectively converting the rotational motion of the motor 3 into a swinging reciprocating motion around the axis of the drive shaft 2 and a reciprocating linear motion of the drive shaft 2 in the axial direction. The conversion mechanism 4, the storage battery 5, the coil 7 for receiving the electric power for charge of the storage battery 5 from the outside, etc. are stored.
[0009]
The motion converting mechanism 4 is provided for the eccentric shaft 8, the first eccentric cam 9, the second eccentric cam 10 and any of the first eccentric cam 9 and the second eccentric cam 10 shown in FIG. An eccentric shaft that is configured by a cam follower 11 that can be engaged and that has a drive shaft 2 connected and integrated, and that is integrally provided with a face gear 13 that meshes with a pinion 12 provided on the output shaft of the motor 3. 8 is rotatably supported by the face gear shaft 14. As shown in FIG. 7, the eccentric shaft 8 includes a first eccentric shaft 15 having an eccentric amount r ₄ with respect to the axis of the face gear shaft 14 and a second eccentric shaft 16 having an eccentric amount r _3. Formed from. Although the first eccentric shaft 15 and the second eccentric shaft 16 are eccentric in the same direction, in the illustrated case, the eccentric amount r ₄ of the first eccentric shaft 15 is the eccentric amount r of the second eccentric shaft 16. _It is larger than ₃ .
[0010]
A second eccentric cam 10 is attached so as to be rotatable with respect to the first eccentric shaft 15 constituting the eccentric shaft 8, and is rotatable with respect to the second eccentric shaft 16 constituting the eccentric shaft 8. An eccentric cam 9 is attached.
A concave portion 18 is formed in the circumferential annular portion of the face gear 13 so as to be surrounded by a ridge 17. The concave portion 18 projects from a rear end surface of a second eccentric cam 10 described later. The engagement protrusion 19 is engaged, and the rotation of the second eccentric cam 10 is restricted by the engagement protrusion 19 hitting the end of the recess 18. The face gear 13 is provided with a stopper function for fixing the eccentric cam position.
[0011]
As shown in FIG. 7, the shaft shaft and the outer peripheral surface of the first eccentric cam 9 are eccentric by r _2, and the shaft shaft and the outer peripheral surface of the second eccentric cam 10 are eccentric by r ₁ . . An engagement groove 20 is recessed in the front end surface of the second eccentric cam 10, and an engagement projection piece 19 protrudes from the rear end surface.
An engaging projection 22 is provided on the rear end surface of the first eccentric cam 9 so that the first eccentric cam 9 and the second eccentric cam 10 formed separately are mounted on the eccentric shaft 8. The first eccentric cam 9 and the second eccentric cam 10 rotate as a result of the engagement between the engagement protrusion 22 and the engagement groove 20 and the eccentric direction of the first eccentric cam 9. And the eccentric direction of the second eccentric cam 10 are reversed by 180 °.
[0012]
The cam follower 11 is formed integrally with the drive shaft 2, and as shown in FIG. 5B, the cam follower 11 surrounding the first eccentric cam 9 and the second eccentric cam 10 is A first follower portion 23 whose upper and lower inner peripheral edges are in contact with the second eccentric cam 10 and a second follower portion 24 whose left and right inner surfaces are in contact with the first eccentric cam 9 are provided. The drive shaft 2 is supported by a bearing 25 so that it can freely move in the axial direction relative to the main body 1 and rotate around the axis.
[0013]
When the eccentric shaft 8 is rotated in the direction indicated by the arrow in FIG. 9 by the motor 3, the rotation of the pinion 12 is transmitted to the face gear 13 due to the engagement relationship between the engagement protrusion 19 and the recess 18. Then, when the face gear 13 is rotated, the engagement protrusion 19 of the second eccentric cam 10 is rotated along the recess 18 of the face gear 13, and the second portion is stopped at the stopper portion at the end of the recess 18. The movement of the eccentric cam 10 is restricted. Next, with respect to the first eccentric cam 9, since the engagement protrusion 22 is engaged with the engagement groove 20 of the second eccentric cam 10, the eccentric slide is interlocked with the movement of the second eccentric cam 10. Positioned while. Here, the center of the face gear shaft 14 and the center of the first eccentric cam 9 are concentric, and the amount of eccentricity of the first eccentric cam 9 is zero. At this time, the second eccentric cam 10 by the eccentric amount r ₄ of the portion slides on the eccentricity r ₁ and the face gear 13 of the second eccentric cam 10, an eccentric amount of total r _{1 +} r ₄ is obtained, Therefore, the cam follower 11 moves in a linear direction with a displacement amount of 2 × (r ₁ + r ₄ ) with respect to the face gear shaft 14, and the drive shaft 2 can take out a linear reciprocating motion. Here, the first eccentric cam 9 is on the concentric axis with the face gear shaft 14, and the amount of eccentricity is zero, so that the rotational motion around the axis of the drive shaft 2 is restricted.
[0014]
Conversely, when the eccentric shaft 8 is rotated in the direction opposite to the direction indicated by the arrow in FIG. 9 by the motor 3, that is, to convert the rotational motion into the swinging reciprocating motion, the motor 3 can be reversed. Due to the reverse rotation of the motor 3, the engaging protrusion 19 of the second eccentric cam 10 is restricted by the recess 18, and the engaging protrusion 22 of the first eccentric cam 9 that rotates and slides in synchronization therewith is the second eccentric cam. Positioning is restricted because it is engaged with the ten engaging grooves 20. Also in this case, the center of the face gear shaft 14 and the center of the second eccentric cam 10 are on the concentric shaft, and the amount of eccentricity is 0. Therefore, the reciprocating linear motion of the drive shaft 2 via the cam follower 11 is restricted. Is done. At this time, the inclined surface 26 of the first eccentric cam 9 abuts on the cam follower 11. The drive shaft 2 together with the cam follower 11 forms a reciprocating motion in the rotational direction at an angle of θ ° shown in FIG. 4, and as a result, the drive shaft 2 takes out the reciprocating motion of the swing. be able to.
[0015]
Therefore, when the rotation direction of the eccentric shaft 8 by the motor 3 is the direction indicated by the arrow in FIG. 9, the center of rotation of the eccentric shaft 8 of the first eccentric cam 9 and the second eccentric cam 10 as described above. On the other hand, since only the second eccentric cam 10 is eccentric and the first eccentric cam 9 is not eccentric, the cam follower 11 has an eccentricity of the second eccentric cam 10 at the first follower portion 23 thereof. Receiving the vertical component of the rotational motion, the drive shaft 2 is reciprocated linearly in the axial direction. At this time, since the toothbrush body is connected in the axial direction of the drive shaft 2, it is possible to polish the bath.
[0016]
When the rotation direction of the eccentric shaft 8 is reversed from the direction indicated by the arrow in FIG. 9 by reversing the motor 3, only the first eccentric cam 9 is eccentric with respect to the rotation center of the eccentric shaft 8, Since the second eccentric cam 10 is not eccentric, the second follower portion 24 of the cam follower 11 in contact with the inclined surface 26 of the first eccentric cam 9 performs the eccentric rotational motion of the second eccentric cam 10. In response to this, the drive shaft 2 is caused to reciprocate around the axis. At this time, since the toothbrush body also performs the same movement, rolling polishing can be performed.
[0017]
That is, two different eccentric amounts are obtained for the three parts of the face gear 13, the first eccentric cam 9, and the second eccentric cam 10 by switching the forward and reverse rotational directions of the motor 3, and the cam follower 11 that contacts the eccentric amount is eccentric. By transmitting the amount, it is possible to perform two operations, a reciprocating linear motion and a swinging reciprocating motion, and to switch between the two types of motion described above. This type of motion conversion mechanism 4 is already known as described above, but the one used here is composed of the first eccentric cam 9 and the second eccentric cam 10 as compared with the conventional one. The difference is that the eccentric amount for obtaining the reciprocating linear motion and the eccentric amount for obtaining the swinging reciprocating motion can be made different from each other. The stroke in the reciprocating linear motion is determined by the eccentricity r ₃ (= r ₁ ) described above, and the swing angle (2θ) in the swinging reciprocating motion is determined by the eccentricity r ₄ (= r ₂ ) and the inclined surface 26. Although it is determined by the axial direction angle and diameter and the distance from the center of the drive shaft 2 to the second follower portion 24, the stroke and the swing angle can be set to appropriate values by making the eccentric amounts r ₃ and r ₄ different. The degree of freedom is high. In FIG. 9, the gap indicated by α is a portion between the engagement protrusion 22 and the engagement groove 20 that is a portion that transmits the rotation of the motor 3 from the eccentric shaft 8 to the first eccentric cam 9 via the second eccentric cam 10. This is a gap generated by the difference in the amount of eccentricity in the engaging portion.
[0018]
By the way, the eccentric amounts of the first eccentric cam 9 and the second eccentric cam 10 with respect to the rotation center of the eccentric shaft 8 are changed depending on the rotation direction of the motor 3, but the first eccentric cam 9 and the second eccentric cam 9 are different. By changing the eccentric direction of the eccentric cam 10, it is possible to cause the drive shaft 2 to perform a combined motion of the shaft reciprocating motion and the swinging reciprocating motion around the shaft, and by switching the motor 3 between forward and reverse rotational directions. The ratio of the two motion components can be made different. In the present invention, this is also included.
[0019]
FIGS. 9 to 13 show the engagement state between the engagement protrusion 22 projecting from the rear end surface of the first eccentric cam 9 and the engagement groove 20 recessed in the second eccentric cam 10. The meshing state of the first eccentric cam 9 and the second eccentric cam 10 when the face gear 13 rotates sequentially from 0 to 180 ° is shown.
Here, in the drawing, the first eccentric cam 9 and the second eccentric cam 10 are omitted from the illustration so that the engagement state between the engagement protrusion 22 and the engagement groove 20 can be easily understood. The engagement groove 20 is illustrated. Although the face gear 13 is originally rotated and moved in the drawing, the first eccentric cam 9 and the second eccentric cam 10 are shown in the state of rotating in the drawing. Also. In FIG. 9, symbol a indicates the rotation center of the engagement groove 20, and symbol b indicates the rotation center of the engagement protrusion 22.
[0020]
FIG. 10 shows a state in which the face gear 13 is rotated by 45 °. When the first eccentric cam 9 is at the 45 ° position, the second eccentric cam 10 is at the 53 ° position, and as shown in FIG. 11, the first eccentric cam 9 is at the 90 ° position. In some cases, the second eccentric cam 10 is 101.4 °, and when the first eccentric cam 9 is at a position of 135 ° as shown in FIG. 12, the second eccentric cam 10 is 142.5 °. When the first eccentric cam 9 is at a position of 180 ° as shown in FIG. 13, both the first eccentric cam 9 and the second eccentric cam 10 rotate 180 °.
[0021]
This is because the eccentric amount between the first eccentric cam 9 and the second eccentric cam 10 is different, and the rotation reference position between the first eccentric cam 9 and the second eccentric cam 10 is different. This is because a difference arises. Therefore, if the joint portion (engagement protrusion 22 and engagement groove 20) of the first eccentric cam 9 and the second eccentric cam 10 has the same square shape, there is a risk of interference during rotation. Therefore, in the present embodiment, as shown in FIG. 14, a curved surface portion 27 that is curved is formed on the side surface portion of the engagement protrusion 22 of the first eccentric cam 9, and the engagement of the second eccentric cam 10. When the first eccentric cam 9 rotates and slides together with the second eccentric cam 10 in a state where the engagement protrusion 22 is engaged with the joint groove 20, the above-described projecting curved surface portion 27 is against the inner surface of the engagement groove 20. Therefore, the sliding movement is smoothly performed without resistance, and the switching between the reciprocating linear motion and the swinging reciprocating motion is smoothly performed.
[0022]
The forward / reverse rotation of the motor is switched by operating an operation switch provided outside the main body 1 or automatically every predetermined time by a control circuit built in the main body 1. The drive is controlled.
[0023]
【The invention's effect】
According to the first aspect of the present invention, a concave portion is formed in a circumferential annular portion of a face gear provided with an eccentric shaft on which the first eccentric cam and the second eccentric cam constituting the motion conversion mechanism are pivotally supported. Since the stopper function for fixing the position of the second eccentric cam is provided, it is possible to select the reciprocating linear motion and the oscillating reciprocating motion by restricting the operating state of the eccentric cam by switching the rotation direction of the motor forward and reverse. The effective contact area of the stopper for regulating the operating state of the eccentric cam can be increased, and a mechanism that does not break or lock against external load or impact load can be saved in space. all SANYO it is possible to provide an electric toothbrush that can be configured in, also a second eccentric cam is inserted into the base portion of the eccentric shaft so as to be positioned outside of the second eccentric cams First eccentric on the eccentric shaft The cam is inserted, the engaging protrusion protruding from the first eccentric cam is engaged with the engaging groove recessed in the second eccentric cam, and bulges outward on both side surfaces of the engaging protrusion. Since the projecting curved surface portion is formed, the first eccentric cam and the second eccentric cam are connected by the engagement of the engaging protrusion with the engaging groove, and the second eccentric cam and the first eccentric cam are connected. When the two eccentric cams co-operate, it is possible to prevent interference between the engagement protrusions of the first eccentric cam and the engagement grooves of the second eccentric cam, and smooth operation switching can be performed without resistance. Monodea Ru.
[Brief description of the drawings]
1A and 1B show an example of the present invention, in which FIG. 1A is a front view and FIG. 1B is a cross-sectional view showing an internal configuration;
2A and 2B show an example of the present invention, in which FIG. 2A is a side view, and FIG. 2B is a cross-sectional view showing an internal configuration.
FIG. 3 is a cross-sectional view showing a state of a reciprocating linear motion of a motion conversion mechanism.
FIG. 4 is a cross-sectional view showing a state of swing reciprocation of the motion conversion mechanism.
5A is a cross-sectional view showing an engagement state between a cam follower and a second eccentric cam during a reciprocating linear motion, and FIG. 5B is a cross-sectional view seen from another direction.
FIG. 6 is a cross-sectional view showing an engagement state between the cam follower and the first eccentric cam during the swing reciprocating motion.
FIG. 7 is a perspective view showing a face gear, a first eccentric cam, and a second eccentric cam.
FIG. 8 is a plan view of a face gear.
FIG. 9 is an explanatory diagram for explaining the action of the stopper function.
FIG. 10 is an explanatory diagram for explaining the action of the stopper function.
FIG. 11 is an explanatory diagram for explaining the action of the stopper function.
FIG. 12 is an explanatory diagram for explaining the action of the stopper function.
FIG. 13 is an explanatory diagram for explaining the action of the stopper function.
14A and 14B show a first eccentric cam, where FIG. 14A is a front view, FIG. 14B is a left side view of FIG. 14A, and FIG. 14C is a right side view of FIG.
[Explanation of symbols]
3 Motor 4 Motion Conversion Mechanism 8 Eccentric Shaft 9 First Eccentric Cam 10 Second Eccentric Cam 13 Face Gear 18 Recess 20 Engaging Groove 22 Engaging Protrusion 27 Projecting Curved Surface

Claims (1)

An electric toothbrush comprising a motor, a motion conversion mechanism that selectively converts the rotation of the motor into two different types of motion according to the direction of rotation of the motor, and a toothbrush body that operates with the output of the motion conversion mechanism, A concave portion is formed in a circumferential annular portion of a face gear having an eccentric shaft on which a first eccentric cam and a second eccentric cam constituting the motion conversion mechanism are mounted, and a second eccentric cam is formed on the base side of the eccentric shaft. And a stopper function for fixing the position of the second eccentric cam in the concave portion of the face gear by attaching the first eccentric cam to the eccentric shaft so as to be located outside the second eccentric cam. A projecting curved surface portion that engages with an engaging groove formed in the second eccentric cam so as to protrude outwardly from the first eccentric cam, and bulges outward on both side surfaces of the engaging protrusion. An electric toothbrush characterized by being formed .

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