JP2001299451A - Toothbrush having function for sensing excessive brushing pressure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothbrush capable of sensing an excessive brushing pressure, clearly informing a user at the point of the excessive brushing pressure and, allowing the user to apply the feeling of the pressure when a conventional toothbrush is used. SOLUTION: A brush head 2 provided with a flocked part 4 at the tip of a short-size shaft body for the toothbrush is rotatably connected to a handle 1 fitted with a holding part 3, and a rotation controlling means for controlling the rotation of the brush head 2 is mounted against the force acting on the after-mentioned position on the position on the side opposite to the flocked part 4 across the position serving as a rotational supporting point and at a shorter distance than the distance between the rotational supporting point and the flocked part 4. The attitude of the flocked part 4 to the holding part 3 is changed from an ordinary one to a warning one by the rotation, using the brushing pressure as motive power, of the brush head 2 when the brushing pressure exerted on the flocked part 4 exceeds a specified value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothbrush having a function of detecting an excessively high brushing pressure and informing a user of the fact.

[0002]

2. Description of the Related Art When brushing teeth, it is important to brush with moderate force. If it is too weak, the stain on the teeth will not be removed, and if it is too strong, it will damage the gums and teeth. The brushing pressure at which the flocked part presses the target site is 200 g-
It is considered preferable that the weight is within the range of 300 g, and it is particularly important that the weight does not exceed 300 g from the viewpoint of avoiding damage to gums and teeth. As a toothbrush from such a viewpoint, for example, a toothbrush in which an elasticity is applied to a neck portion and an excessive brushing pressure is reduced by the elasticity is conventionally known. However, this toothbrush merely provides a buffering effect so that brushing does not become excessive, and since this buffering is performed automatically without the user's awareness, the user can use the brushing pressure. However, there is a problem that a normal brushing pressure cannot be obtained indefinitely without noticing the fact that the amount is excessive.

[0003] One solution to such a problem to a certain extent is disclosed in US Patent No. 5,355,544. In this case, the toothbrush is housed in an internal hollow cylindrical holder with one end opened with the outer surface as the gripping part, with the thin rear half part inserted deep into the holder, and the vicinity of the holder mouth part As a rotation fulcrum, the flocked portion is configured to be swingable outside the holder, and a magnet piece is attached to the handle base end of the toothbrush accommodated in the holder and the holder inner wall facing the handle base end, and the flocked portion is mounted on the flocked portion. When the applied brushing pressure exceeds a specified value, the magnetized state of the magnet pieces is released, and the posture of the flocked portion with respect to the holder is tilted to a warning posture for warning of excessive brushing pressure.

[0004]

In this device, it is possible to know that the brushing pressure has become excessive by the change in the posture of the flocked portion. However, this device uses a relatively long toothbrush handle inserted deeply into the holder. Because it is a structure that changes posture in a limited space inside the holder,
Since the restriction on the amount of change in the posture of the handle in the holder appears as a limitation on the amount of swing of the flocked portion, the user cannot clearly increase the amount of change in the flocked portion and inform the user in a clear form that the user has shifted to the warning posture. There was a problem that can not be. Of course, if the holder diameter is increased, the amount of swing of the flocked portion can be increased. However, in this case, the operation feeling is significantly different from that of a normal toothbrush, and a problem arises in that the operation feeling learned cannot be applied to a normal toothbrush. It is also conceivable to cut out the base end of the holder and expose the base end of the handle that tilts from that part, thereby increasing the amount of swinging of the flocked portion. Is extremely bad and unrealistic. In addition, in this case, the moisture that has entered the inside hollow holder is difficult to dry, and the inside of the holder may become a hotbed of various bacteria.

[0005] The present invention has been made in view of such a situation, it is possible to clearly notify the user of the situation where the brushing pressure has become excessive, and, furthermore, the operating feeling learned with the toothbrush is used as it is in an ordinary manner. An object of the present invention is to provide a toothbrush having an excessive brushing pressure sensing function which can be applied as a feeling of operation with a toothbrush and can adopt a structure in which moisture and the like hardly remain.

[0006]

As a result of studies by the present inventor, the above-mentioned problem has been solved more than the distance from the pivot point to the flocking portion.
The present invention has been completed by noting that it can be solved by setting the distance from the pivot point to the base end of the handle to be short. In order to make the structure in which moisture and the like hardly remain, it is only necessary to use a holder having a hollow inside. The present invention completed on the basis of this idea connects a brush head provided with a flocked portion at the tip of a short toothbrush shaft to a handle provided with a grip portion so as to be rotatable, Rotation of the brush head at a position opposite to the flocking portion across the position serving as a rotation fulcrum, and at a position separated by a distance shorter than the distance between the rotation fulcrum and the flocking portion against the acting force at the position When the brushing pressure applied to the flocked portion exceeds a specified value, the brush head is rotated by the brushing pressure as a driving force, so that the posture of the flocked portion with respect to the grip portion during normal brushing is provided. The posture is switched from a normal posture, which is a posture, to a warning posture for warning of excessive brushing pressure.

In the toothbrush having such a configuration, the brush head functions as a lever, and the brushing pressure applied to the flocked portion as a point of force acts on the base end of the brush head as an acting force having a magnitude corresponding to the lever ratio. Will be. When the brushing pressure acts on the flocking portion, the brush head tries to rotate around the rotation fulcrum. However, since the rotation restricting means is associated with the base end of the brush head, the rotation is suppressed, and the rotation during normal operation is suppressed. Attempts to maintain a normal posture, which is a brushing posture. When the brushing pressure exceeds the prescribed value, the posture is switched to a warning posture for warning that the pressure is excessive. Here, the pressure which the rotation restricting means should resist may be a tensile force or a pressing force.
These differences depend on the manner in which the rotation restricting means is connected to the base end of the brush head. However, in general, it is easier to reduce the size of the mechanism by using a pulling force.

Further, there are roughly two ways of suppressing rotation. One is that the brushing pressure keeps the normal posture when the brushing pressure is equal to or lower than the specified value. However, when the brushing pressure exceeds the specified value, the holding state is released at once and becomes a free state. This free state is called a warning posture. Another is that the inclination angle of the brush head with respect to the handle gradually increases with an increase in the brushing pressure, and the posture gradually changes from a normal posture to a warning posture. The former can be described as a discontinuous operation, and the latter can be described as a continuous operation.

As an example of the former, for example, a combination of magnet pieces attracting each other or a magnet piece and a magnetic material attracted by the magnet pieces are provided between the base end of the brush head and a corresponding portion of the handle facing the brush head. Another example is a brush head that engages with a recess provided on the base end face of the brush head and the recess provided at a corresponding position of the handle facing the brush head. And a means for pressing in the longitudinal direction. In these cases, the posture change is performed at once, so that the shift to the warning posture can be clearly transmitted to the user.

On the other hand, as an example of the latter, the base end of the brush head is buried and supported in a synthetic elastic adhesive filled at the distal end of the handle, and the restraining force on the base end of the brush head by the synthetic elastic adhesive is used as posture holding means. And the like used. It is preferable to use a urethane-based elastic adhesive or a modified silicone-based elastic adhesive as the synthetic elastic adhesive. In this device, since the posture change from the normal posture to the warning posture is performed gradually and continuously, it is somewhat disadvantageous in making the user aware of the fact of the transition to the warning posture, but on the other hand, the sudden Since there is no change in posture, safety is excellent.

When the posture change is continuous, it is preferable to use some notification means in order to more clearly notify the user of the shift to the warning posture. For example, an electric contact is provided at the base end of the brush head and at a corresponding position on the handle side facing the brush head so that energization and cutoff are switched with rotation of the brush head, and operation controlled by the switching is performed. For example, the provision of a target notification means. In the case where such a means is used in combination, the transition to the warning posture is transmitted to the user in a more clear form. It should be noted that such a combined use of the electric notifying means is particularly effective when the posture change is continuous, but may be applied to the case where the posture change is discontinuous.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will now be described with reference to the illustrated embodiments. FIG. 1 shows a first embodiment of the present invention, in which (a) shows a side view and (b) shows a front view. In the present toothbrush, the toothbrush is divided into a first half and a second half in the longitudinal direction. The first half of the toothbrush is called a brush head 2, while the second half of the toothbrush is called a handle 1.

In the illustrated embodiment, the brush head 2 is close to the shape of a typical toothbrush with the rear half cut off, while the handle 1 is close to the shape of a typical toothbrush with the front half cut off. Its overall shape resembles the shape of a typical toothbrush. This makes it possible to apply the operational feeling obtained with the present toothbrush as it is to a normal toothbrush. It is important that the shape of the toothbrush does not significantly deviate from a general toothbrush from the viewpoint of giving versatility to the operation feeling, but adopting a more novel shape on the assumption that there is no significant effect on the operation feeling Is also good.

The brush head 2 has a short toothbrush shaft provided with a flocked portion 4 at the tip thereof.
The brush head 2 is rotatably connected to the handle 1 by a rotating shaft 5. Alternatively, a non-slip portion 8 to which a finger is applied is provided at a position closer to the connecting portion than the grip portion 3 of the handle 1. Non-slip part 8
May be rough surface processing such as knurling,
It may be formed by attaching a rubber member.

As shown in FIGS. 1 and 2, the brush head 2 is sandwiched on both sides on the base side by a rod 1a (hereinafter referred to as a parallel rod 1a) extending in parallel from the handle 1, and the two parallel rods 1a, 1a are sandwiched. The shaft body 5a is connected to the shaft holes 1c, 1c formed in the shaft member and the shaft hole 2c formed in the base of the brush head so as to be rotatable with respect to the handle. Abutment walls 2b, 1b for restricting the rotation direction of the brush head 2 in one direction are provided on the brush head base and on the handle side facing the brush head base.
And magnet pieces 6a and 6b as posture holding means for holding the posture where the contact walls 2b and 1b are in contact with each other. Instead of providing both magnet pieces, one may be replaced with an iron piece or the like. Various magnets such as cast magnets, sintered magnets, and plastic magnets can be used as the magnet pieces 6a and 6b, but it is preferable to use plastic magnets because they are lightweight and have excellent corrosion resistance. It goes without saying that in selecting a material, a material suitable for use in the mouth is selected.

When the brush head base and the corresponding contact walls 2b, 1b provided on the handle side abut against each other, the brush head 2 does not rotate except in the direction in which the magnet is released from the attracted state. Like that. In addition, when the magnet pieces 6a, 6b provided on the contact surfaces of the contact walls 2b, 1b are magnetically attached, the flocking portion 4 is formed.
The rotation is not started unless the brushing pressure applied to the motor does not exceed a preset specified value.

The brush head constitutes a lever mechanism that uses the rotation shaft 5 as a rotation fulcrum, the flocked portion 4 as a power point, and an attachment point of the magnet pieces 6a and 6b as an action point.
As shown in (a), the brush head 2 is in a normal posture at the time of normal brushing, which is on an extension of the handle 1 in the longitudinal direction, and an excessive brushing pressure at which the flocking portion 4 is bent in the longitudinal direction of the handle 1. Is switched to a warning posture for warning. Then, when the brushing pressure is applied to the flocking portion 4, the brushing pressure acts on the magnet piece mounting portion, which is the emphasis point, according to the leverage ratio, so that the attracted magnet pieces are separated from each other, and the magnet pieces are separated from each other. When the force exceeds the magnetic adhesion by the magnet pieces 6a and 6b, the normal posture is released and the state shifts to the warning posture. Here, the warning posture is the magnet piece 6a,
6b is in a free state in which the magnetic attachment is released, that is, the magnet piece 6
This indicates a state in which the restraint by the a and 6b is released and the vehicle can rotate freely. However, a case where the steering wheel 1 has a specific inclination angle with respect to the steering wheel 1 is defined as a warning posture, and a distance between a normal posture and a warning posture at a specific angle is determined. The transition may be made alternatively.
Here, the longitudinal direction of the brush head 2 is the handle 1
Is defined as a normal posture, but the normal posture is not limited to this, and for example, a bending posture with respect to the longitudinal direction of the handle 1 may be the normal posture.

As shown in FIG. 1, the detachment force acting on the magnet piece attachment point, which is the point of action, is applied to the rotating shaft 5 and the flocking portion 4.
A and the distance B between the rotating shaft 5 and the magnet piece attachment point
And the magnitude of B / A, which is the ratio of As B / A becomes smaller, the separating force acting on the magnet pieces becomes larger, so that the magnet pieces 6a and 6b need to have a high magnetic force. A larger B / A is advantageous in that a low magnetic force can be used as the magnet piece. However, if the B / A is increased, the distance from the rotating shaft 5 to the point of action is increased. In order to make the inclination angle of the flocking portion in the posture large enough, the stroke in the rotation direction of the base end of the brush head must be increased, and this portion becomes an obstacle to grasping, If the part is in the oral cavity, the oral cavity may be damaged. In order to avoid such a problem, the inclination angle of the flocking portion 4 at the time of the warning posture may be kept within a small range. However, in this case, it is clear to the user that the flocking portion 4 has changed the posture to the warning posture. It is difficult to inform by form. In the present invention, B / A is reduced to 1 in consideration of these.
It is set as follows. A more preferable range of B / A is 0.1.
It is in the range of 3 to 0.7. In this range, the inclination angle of the flocking portion 4 with respect to the grip portion 3 in the warning posture is used while keeping the stroke of the base end portion of the brush head in the rotation direction within a range that does not cause danger to the oral cavity. It can be large enough for a person to notice a change in the warning posture.

Although the embodiment described herein is an embodiment of the present invention, various modifications are conceivable for the present invention. For example, the shaft body that rotatably supports the brush head may be configured to be detachable from the handle so that the brush head can be replaced as needed. In this way, when the flocked portion is worn out, the brush head can be continuously used by replacing only the brush head, and a brush head suitable for the user can be selected. Also, as shown in FIG. 4, a plurality of shaft holes 1c and 2c corresponding to both the handle side and the brush head side may be provided so that the position of the pivot point in the longitudinal direction can be changed. By doing so, the magnitude of B / A can be changed, so that the magnitude of the brushing pressure when shifting to the warning posture can be changed. The magnitude of the brushing pressure when shifting to the warning posture is approximately 2 in terms of the surface pressure of the flocking surface.
Set within the range of 00 g to 300 g.

As shown in FIG. 5, the periphery of the portion where the brush head moves up and down on the distal end side of the handle is covered with an elastic sheet 7 so that the base end of the brush head protruding from the handle 1 does not damage the inside of the oral cavity. It is also preferable to do so.

Further, another form can be adopted as the posture holding means for maintaining the normal posture against the brushing pressure. The posture holding means can be broadly classified into those in which the posture change from the normal posture to the warning posture is discontinuous and continuous. As represented by the example of the magnet piece, the discontinuous one keeps the normal posture when the brushing pressure acting on the flocked portion is within the specified value or less, and the holding state is released when the brushing pressure exceeds the specified value. This means that the posture changes all at once, and then becomes free.
On the other hand, a continuous one refers to one that gradually changes from a normal posture to a warning posture in a constantly restrained state.
In the above-described embodiment, the case where the magnet piece is used as an example of the continuous attitude holding means has been described, but another means can be used. For example, the second embodiment shown in FIG. In this embodiment, the posture of the normal state is maintained by pressing the base of the brush head 12 in the longitudinal direction to restrain the rotation mechanism. That is, a hemispherical concave portion 12a is provided on the base end surface of the brush head 12, while a ball plunger 15 is provided on the handle 11, and the ball 15a at the tip of the ball plunger fits into the concave portion 12a to assume a normal posture. While holding, the operation of the brush head 12 to rotate causes the ball 15a to travel along the inner peripheral surface of the concave portion, and as a result, the ball 15a falls out of the concave portion 12a, whereby the normal posture is released. is there. A specific mechanism of the ball plunger 15 provided on the handle 11 can be appropriately selected as long as it can repeatedly fit into and release from the recess 12a in a pressurized state. A ball 15a is provided on one end opening side of the through hole provided in the
The compression spring 1 is moved by a shaft 15c which advances and retreats through the through-hole 5a.
A configuration in which pressing is performed using the restoring force of 5b is adopted. The ball plunger 15 is provided with an adjusting groove 15d which can be rotated by a flathead screwdriver or the like at the rear end of the shaft rod.
The pressing force of 5a can be adjusted, so that the magnitude of the brushing pressure when shifting to the warning posture can be adjusted. Reference numeral 16 denotes a cushioning material provided to reduce the impact when the back surface of the flocked portion whose posture has changed hits the tissue in the oral cavity.

In the above description, the posture change of the warning posture is performed at once by releasing the holding of the normal posture.
That is to say, although the operation is performed discontinuously, the third embodiment shown below is a case where the posture change from the normal posture to the warning posture is performed gradually, that is, continuously. In this embodiment, the brush head is not connected by the rotating shaft as in the above-described embodiments, but is buried and supported by the base end of the brush head in a synthetic elastic adhesive filled in the distal end of the handle. It is rotatably supported. The concept of rotation here refers to all the types in which the flocking portion located on the tip side of the brush head turns around the vicinity of the boundary between the brush head and the handle, and even those that do not have a clear rotation axis. It is a concept that falls into the category. In the embodiment shown in FIG. 7, a core 25 that is exposed to the outside from the base end through the rear half of the brush head 22 is provided.
5 is buried in a synthetic elastic adhesive 23 filled at the handle tip so that the brush head 22 can continuously tilt while receiving a restraining force due to the elastic deformation force and elastic restoring force of the synthetic elastic adhesive 23. It is composed. As the synthetic elastic adhesive 23, a urethane elastic adhesive, a modified silicon elastic adhesive, or the like can be used. By the way, when the posture of the brush head 22 changes continuously as described above, it is determined whether the degree of the deformation indicates that the excessive brushing pressure has already occurred or whether the brush head 22 is in the middle of reaching the brushing pressure. There is a difficulty that it is difficult. Therefore, in this embodiment, electric contacts to be energized are provided at the base end 26 of the core body 25 and a corresponding portion of the handle 21 facing the base end 26, and a sound source 27a such as a buzzer is provided inside the handle.
Notification means 27 provided with a light source 27b such as a light source or a light emitting diode, and by controlling the operation of the electric notification means 27 by turning on and off the electric contacts, the fact of shifting to the warning posture can be reliably used. To be able to tell people. Here, both the sound source and the light source are used as the electric notifying means, but either one may be provided, or the other notifying means may be used together. In the toothbrush of this embodiment, the posture change is performed gradually and continuously,
Since there is no sudden change in posture, there is an advantage that there is no impact accompanying the change in posture.

As described above, the toothbrush having an excessive brushing pressure sensing function according to the present invention can notify the user of the fact that the brush head has reached the warning posture,
In addition, since the amount of change in the posture of the flocked portion can be made sufficiently large while keeping the stroke of the base end of the brush head within a small range, anyone can easily know that excessive pressure has been applied. Therefore, it is possible to easily learn how to brush with an appropriate brushing pressure without damaging the gums and teeth.

[0024]

By using the toothbrush according to the present invention,
It is possible to accurately notify the user of the situation where the brushing pressure has become excessive, and to allow the user to obtain an appropriate brushing pressure without damaging the gums and teeth. In addition, this toothbrush secures a large amount of change in the posture of the flocked portion with respect to the gripping portion while keeping the amount of protrusion in the handle thickness direction on the base end side of the brush head in the warning position within a small range, so damage to the oral cavity Therefore, it is possible to reliably notify the user of the excessive brushing pressure without increasing the danger of giving the excessive brushing force or reducing the operability during use. In addition, since the protrusion amount of the base end of the brush head is suppressed to be small, there is no need to consider the design for relatively reducing the protrusion amount of the base end of the brush head, such as increasing the thickness of the handle. The overall shape of the toothbrush can be made to be the same shape as a normal toothbrush, so it can be used with the same feeling as a normal toothbrush, and the operation feeling learned with this toothbrush can be used as it is with a normal toothbrush It can be applied to the operation when there is. Further, since the toothbrush according to the present invention has a small protrusion amount on the base end side of the brush head, there is no need to provide a structure such as housing the base end side of the brush head in the hollow handle, so that it is possible to prevent water droplets from remaining. .

According to a second aspect of the present invention, the rotation restricting means comprises:
When the function of maintaining the normal posture against the pulling force is provided, the mechanism of the rotation restricting means becomes compact.

As described in claim 3, when the posture switching from the normal posture to the warning posture is a discontinuous operation that does not involve posture stability during the switching, the transition to the warning posture is performed rapidly and all at once. It is possible to inform the user in a clear form of the fact that the user has shifted to the posture.

When the switching from the normal posture to the warning posture is a continuous operation as described in claim 4, there is no impact associated with the transition to the warning posture, and a safer toothbrush can be provided.

When a combination of magnets or a combination of magnets and magnetic material is used as the posture holding means, the normal posture can be surely held without complicating the mechanism.

According to a sixth aspect of the present invention, the posture holding means comprises a concave portion provided on the base end face of the brush head, and an elastic body which engages with the concave portion and presses the brush head in the longitudinal direction. In this case, by providing a means for adjusting the pressing force by the elastic body, the brushing pressure for shifting to the warning posture can be adjusted.

When the base end of the brush head is buried in a synthetic elastic adhesive and supported on the distal end of the handle as described in claim 7, there is no impact when shifting to the warning posture, and the structure is simple. A toothbrush having a function of sensing excessive brushing pressure can be provided.

According to a ninth aspect of the present invention, an electric contact is provided at a base end of the brush head and a corresponding position on the handle side facing the brush head, and an electric notifying means is provided which is operated by turning on and off the electric contact. In this case, the shift to the warning posture can be communicated to the user in a more clear form. Especially when the transition from the normal posture to the warning posture is a continuous operation, a toothbrush that does not involve an impact when transitioning to the warning posture and that can inform the user of the fact that the posture has been changed to the warning posture can be surely notified to the user. Can be provided.

[Brief description of the drawings]

FIG. 1 is a first embodiment of the present invention, in which (a) is a side view and (b) is a front view.

FIG. 2 is an exploded view of the vicinity of a rotating part in the embodiment.

FIG. 3 is an explanatory cross-sectional view of the vicinity of the rotating portion.

FIG. 4 is an explanatory view showing a modification in which the mounting position of the rotating shaft can be moved in the embodiment.

5A and 5B show a modified example in which an elastic sheet is coated around a base end of a brush head in the embodiment, wherein FIG. 5A is a side view and FIG.

FIG. 6 shows a second embodiment of the present invention, wherein (a) is a side view and (b) is a front view.

FIG. 7 is an explanatory view showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Handle 1a Parallel rod 1c, 2c Shaft hole 2 Brush head 2c Shaft hole 3 Grasping part 1b, 2b Contact wall 4 Flooding part 5 Rotating shaft 5a Shaft 6a, 6b Magnet piece 7 Elastic sheet 8 Non-slip part 11 Handle Reference Signs List 12 brush head 12a recess 15 ball plunger 15a ball 15b compression spring 15c shaft 15d adjusting groove 21 handle 22 brush head 23 synthetic elastic adhesive 25 core body 26 base end 27 electric notification means 27a sound source 27b light source

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toru Kitano 2-10-1 Kameduro, Takatsuki-shi, Osaka F-term (reference) 3B202 AA06 AB07 AB08 CB08 GA00

Claims (9)

[Claims] 1. A brush head provided with a flocked portion at the tip of a short toothbrush shaft is rotatably connected to a handle provided with a grip portion, and a position serving as a rotation fulcrum is determined. A rotation restricting means for restricting the rotation of the brush head at a position opposite to the flocking portion and at a distance shorter than the distance between the rotation fulcrum and the flocking portion with a force applied thereto; When the brushing pressure applied to the flocking portion exceeds a specified value, the brush head is rotated from the normal posture, which is the posture during normal brushing, by rotating the brush head using the brushing pressure as a driving force. A toothbrush having an excessive brushing pressure sensing function that switches the posture to a warning posture that warns of excessive pressure. 2. A toothbrush having an excessive brushing pressure sensing function according to claim 1, wherein said rotation restricting means is a posture holding means for maintaining a normal posture against a tensile force acting on said means. 3. The posture switching from the normal posture to the warning posture is a transition from a restrained state to a released state, and is a discontinuous operation that does not involve a posture stable state during the transition. Item 3. A toothbrush having an excessive brushing pressure sensing function according to item 1 or 2. 4. The toothbrush having an excessive brushing pressure sensing function according to claim 1, wherein the switching of the posture from the normal posture to the warning posture is a continuous operation performed while being restrained. 5. The method according to claim 2, wherein the posture holding means is constituted by a combination of a magnet to be attracted or a combination of a magnet and a magnetic body disposed to face the base end of the brush head and the tip of the handle facing the brush head. Toothbrush with excessive brushing pressure sensing function. 6. A brush head comprising: a recess provided in a base end face of a brush head; and a means for engaging the recess in a normal posture to press the brush head in a longitudinal direction, and the brushing pressure is used as a driving force. 4. The toothbrush having an excessive brushing pressure sensing function according to claim 2, wherein the magnitude of the pressing force is set so that the engagement relationship is released when the rotational power exceeds a prescribed value. 7. The brush head according to claim 4, wherein the base end of the brush head is buried and supported in a synthetic elastic adhesive filled in the handle distal end, and a restraining force of the synthetic elastic adhesive on the base end of the brush head is used as a posture holding means. Toothbrush with excessive brushing pressure sensing function. 8. The toothbrush having a function of sensing excessive brushing pressure according to claim 7, wherein the material of the synthetic elastic adhesive is a urethane-based elastic adhesive or a modified silicon-based elastic adhesive. 9. An electric notifying means which is provided with an electric contact at a base end of the brush head and a corresponding position on the handle side facing the brush head, and which is controlled by energization and cutoff of the electric contact with rotation of the brush head. A toothbrush having an excessive brushing pressure sensing function according to any one of claims 1 to 8, which is provided.