JP2020018870A - toothbrush - Google Patents

Abstract

To provide a toothbrush that can suppress damage in a user's oral cavity.SOLUTION: A toothbrush has: a head part 14 having a bristle implanted surface on an end side; a handle part 16 which is arranged on a rear end side of the head part and includes a handle part body 31; and a neck part 15 connecting the head part and the handle part. The neck part houses a hard member 17 formed by a hard resin extending in the extension direction of the neck part inside, and has an area coated with a soft resin. An end part on the rear end side of the hard member is positioned on an end side of the handle part. The handle part houses with the soft resin, an end part on the rear end side of the hard member on an end side, forms the rear end side of the end part on the rear end side of the hard member all by soft resin and, when an external force in the direction from the rear end side toward the end side is given, bends.SELECTED DRAWING: Figure 1

Description

The present invention relates to a toothbrush, and more particularly, to a toothbrush capable of suppressing damage to an oral cavity of a user.
Priority is claimed on Japanese Patent Application No. 2014-177334, filed Sep. 1, 2014, the content of which is incorporated herein by reference.

  Conventionally, when a toothbrush is used (specifically, in a state where the toothbrush is held in the mouth), there is a case where an oral trauma is caused by a fall, particularly when the user of the toothbrush is an infant of 1 to 3 years old. In many cases, oral trauma occurs.

Conventionally, there is a toothbrush disclosed in Patent Literature 1 as a toothbrush capable of suppressing loss or breakage of a head portion and a neck portion.
Patent Literature 1 discloses a toothbrush in which a coating layer made of a soft resin is formed on a surface of a base made of a hard resin so as to cover 70% or more of a total of a surface area of a head portion and a surface area of a neck portion. ing.

  Further, in Patent Document 1, the total thickness of the head portion and the neck portion (the total thickness of the thickness of the base and the thickness of the coating layer covering the base) is set to 3 to 5 mm, It is disclosed that the thickness of the base constituting the neck portion is 2 to 4 mm and the thickness of the coating layer is 0.5 to 2 mm (preferably 0.8 to 1.5 mm).

  Patent Literature 1 discloses that the above configuration makes it possible to prevent the handle body from being broken even when an excessive load is applied to the head portion or the neck portion, or that the head portion or the neck portion is broken. It is disclosed that even in the case of being exposed, it is possible to suppress the exposure of the broken portion due to the coating layer.

In the toothbrush disclosed in Patent Literature 1 having the above-described configuration, since the base that constitutes the tip of the head is covered with the soft resin, the toothbrush is strongly chewed, or the tip of the head is strongly hit in the oral cavity. Then, the soft resin functions as a cushion material.
Therefore, by using the toothbrush disclosed in Patent Literature 1, it is possible to suppress damage in the oral cavity due to the tip of the head.

JP 2013-458A

However, the neck portion of the toothbrush disclosed in Patent Literature 1 is thinner and softer than the base so as to cover the surface of the base (2 to 4 mm in thickness) constituting the neck portion. (A preferable thickness is 0.8 to 1.5 mm).
For this reason, the neck portion of the toothbrush disclosed in Patent Document 1 is configured such that the ratio of the base made of hard resin is higher than that of soft resin.

For this reason, when an external force is applied to the head portion of the toothbrush disclosed in Patent Literature 1, for example, in the extending direction of the toothbrush (specifically, the direction from the rear end to the front end of the toothbrush), It was difficult to bend so that the external force transmitted to the tip of the head portion was sufficiently released so that the inside of the mouth was not damaged (however, it was easier to bend than when all were made of hard resin).
Therefore, if a strong external force is applied in the direction from the rear end to the front end of the toothbrush while holding the toothbrush disclosed in Patent Document 1 in the mouth, there is a possibility that the oral cavity of the user may be damaged.
In particular, when the user of the toothbrush is an infant of 1 to 3 years, the risk of damage to the oral cavity increases.

  The present invention has been made in view of the above problems, and has as its object to provide a toothbrush capable of suppressing damage in the oral cavity of a user.

  According to a first aspect of the present invention, a head portion having a flocking surface on a distal end side, a handle portion disposed on a rear end side from the head portion and including a handle portion main body, and the head portion and the handle portion are provided. A neck portion to be connected, the neck portion accommodates a hard member formed of a hard resin extending in a direction in which the neck portion extends, and has a region covered with a soft resin, The rear end of the hard member is located at the distal end of the handle, and the handle is accommodated with the soft resin at the distal end of the hard member at the distal end. The rear end side of the hard member is formed entirely of the soft resin from the rear end side, and the handle portion is bent when an external force is applied in a direction from the rear end side to the front end side. Is provided.

  Further, in the toothbrush according to one aspect of the present invention, a ratio of the hard member to an area of a cut surface orthogonal to the extending direction of a central portion of the neck portion in the extending direction is 5% or more and 50% or more. %.

  In the toothbrush according to one aspect of the present invention, the neck portion has a region in which the hard member is covered with the soft resin in a non-exposed state in an entire circumferential direction around an axis extending in the extending direction. It is characterized by the following.

  Further, in the toothbrush according to one aspect of the present invention, the hard member includes a plurality of protruding portions that are exposed and protruded in a circumferential direction around the axis on the rear end side in the extending direction. And

  Further, in the toothbrush according to one aspect of the present invention, a cross-sectional shape of the hard member decreases from the protrusion to the rear end.

  Further, in the toothbrush according to one aspect of the present invention, when an external force is applied in a direction from the rear end side to the front end side, both the neck portion and the handle portion are bent.

  ADVANTAGE OF THE INVENTION According to the toothbrush of this invention, damage to the oral cavity of a user can be suppressed.

It is a side view of the toothbrush concerning embodiment of this invention. It is a front view of the toothbrush shown in FIG. It is a rear view of the toothbrush shown in FIG. It is the side view to which the hard member shown in FIG. 1 was expanded. FIG. 3 is an enlarged front view of the hard member shown in FIG. 2. FIG. 4 is an enlarged rear view of the hard member shown in FIG. 3. FIG. 5 is a cross-sectional view of the hard member shown in FIG. 4 taken along the line AA. FIG. 5 is a cross-sectional view of the hard member (specifically, a first portion) shown in FIG. 4 taken along line BB. FIG. 5 is a cross-sectional view of the hard member (specifically, a second portion) shown in FIG. 4 taken along the line CC. FIG. 5 is a cross-sectional view of the hard member (specifically, a second portion) shown in FIG. 4 taken along the line DD. It is sectional drawing which shows the manufacturing process of the toothbrush of this Embodiment, and is a figure for demonstrating the process of forming a hard member using a 1st metal mold | die. It is sectional drawing which shows the manufacturing process of the toothbrush of this Embodiment, and is a figure for demonstrating the process of forming a 1st soft resin, a soft part, and a handle part main body using a 2nd metal mold | die. . It is a side view which shows the modification of the toothbrush which concerns on embodiment of this invention. It is a front view of the toothbrush shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings used in the following description are for describing the configuration of the embodiment of the present invention, and the sizes, thicknesses, dimensions, and the like of the illustrated portions may be different from the actual dimensional relationship of the toothbrush. is there.

(Embodiment)
FIG. 1 is a side view of the toothbrush according to the embodiment of the present invention. FIG. 2 is a front view of the toothbrush shown in FIG. In FIG. 2, for convenience of explanation, illustration of the brush unit 12 including the plurality of hair bundles 12-1 illustrated in FIG. 1 is omitted. FIG. 3 is a rear view of the toothbrush shown in FIG.
FIG. 4 is an enlarged side view of the hard member shown in FIG. FIG. 5 is an enlarged front view of the hard member shown in FIG. FIG. 6 is an enlarged rear view of the hard member shown in FIG.

In the structures shown in FIGS. 1 to 6, the same components are denoted by the same reference numerals. The X direction shown in FIGS. 1 to 6 indicates the extending direction of the handle body 11 (the extending direction of the neck portion 15) when the toothbrush 10 is not used.
The Y direction shown in FIGS. 2, 3, 5, and 6 indicates the width direction of the toothbrush 10 (in other words, the second direction orthogonal to the Z direction and the X direction).
The Z direction shown in FIGS. 1 and 4 indicates a first direction orthogonal to the flocked surface 21-1b when the toothbrush 10 is not used.
4 to 6, reference numerals of components of the toothbrush 10 other than components of the hard member 17 are also illustrated for convenience of description.

Referring to FIGS. 1 to 6, the toothbrush 10 of the present embodiment has a handle body 11 and a brush unit 12.
The handle body 11 has a head portion 14, a neck portion 15, a handle portion 16, and a hard member 17 which forms a part of the head portion 14, the neck portion 15, and the handle portion 16.
In the present embodiment, the neck portion in which the width in the second direction (Y direction) is smaller than the width of the head portion 14 (the maximum width in the Y direction) is provided between the flocking surface 21-1b and the handle portion 16. The toothbrush 10 on which the reference numeral 15 is arranged will be described.

The head section 14 has a base member 21 made of a hard resin, and a first soft resin 22 that covers a part of the base member 21. The base member 21 is a part of a component of the hard member 17 made of a hard resin, and has a base member main body 21-1 and two support portions 21-2.
The base member main body 21-1 reduces the outer shape of the head portion 14 by about 1 to 2 mm so that the first soft resin 22 can be arranged on the side surface and the bottom surface 21-1a of the base member main body 21-1. Shape. The base member main body 21-1 has a tip portion 21-1A, a bottom surface 21-1a, a flocking surface 21-1b, and a flocking hole 21-1B.

  The tip 21-1A is a portion of the base member main body 21-1 that is located on the side opposite to the side where the head 14 and the neck 15 are connected. The tip portion 21-1A is a portion facing the inside of the mouth of the user when the user brushes the tooth using the toothbrush 10. The shape of the tip portion 21-1A may be, for example, a round shape (round shape).

  FIG. 7 is a cross-sectional view of the hard member shown in FIG. 4 taken along the line AA. 7, the same components as those of the structure shown in FIGS. 1 to 6 are denoted by the same reference numerals. In FIG. 7, for convenience of description, reference numerals of components of the toothbrush 10 other than components of the hard member 17 are also illustrated.

  Referring to FIGS. 1, 3, 4, 6, and 7, the bottom surface 21-1 a is a portion covered with the first soft resin 22 and is disposed on the opposite side of the flocking surface 21-1 b. ing. The bottom surface 21-1a can be, for example, a flat surface.

The flocking surface 21-1b is a flat surface. The flocking surface 21-1b exposes a plurality of flocking holes 21-1B. The flocking surface 21-1b is exposed from the first soft resin 22 as a first exposed portion in the head portion 14.
As described above, the base member main body 21-1 is formed using the hard resin harder than the first soft resin 22, and the plurality of flocked holes 21-1 </ b> B and the flocked surface 21-1b are separated from the first soft resin 22. By exposing, the hair bundle 12-1 constituting the brush part 12 can be planted (planted) in the plurality of planted holes 21-1B by using the flat wire planting method.

The flocked surface 21-1b is used to mold the first soft resin 22, the soft portion 26, and the handle portion main body 31 using a second mold 51 shown in FIG. -2 (see FIG. 12).
As described above, the flocked surface 21-1b comes into contact with the inner surface of one of the molds 51-2 constituting the second mold 51, so that the plurality of flocked holes 21-1B and the flocked surface 21-1b have first contact. Can be suppressed from being formed.

A plurality of flocked holes 21-1B are provided in the base member main body 21-1 on the side forming the flocked surface 21-1b. The hair implantation holes 21-1B are holes into which the hair bundles 12-1 constituting the brush portion 12 are implanted.
As the arrangement of the plurality of flocking holes 21-1B, for example, an arrangement as shown in FIG. 2 can be used. However, the arrangement is not limited thereto, and any arrangement such as a so-called grid-like arrangement or a staggered arrangement can be used. It may be an array pattern.
Further, the number of the plurality of flocked holes 21-1B is not limited to the number of the flocked holes 21-1B shown in FIG. 2, and can be appropriately set, for example, within a range of 10 to 60 holes.
That is, the arrangement of the plurality of flocking holes 21-1B and the number of the flocking holes 21-1B can be appropriately set according to the purpose.

The shape of the flocking hole 21-1B is not particularly limited, and for example, a perfect circular shape, a circular shape such as an ellipse, a polygonal shape such as a triangular shape or a square shape, or the like can be used.
In addition, the diameter of the flocking hole 21-1B can be determined according to the thickness of the bristle bundle 12-1, and specifically, for example, can be appropriately set within a range of 1 to 3 mm.

  When the thickness of the head portion 14 in the Z direction is 5.0 mm, the thickness of the base member main body 21-1 in the Z direction (in other words, the thickness between the bottom surface 21-1a and the flocking surface 21-1b) is For example, it can be set to 4.2 mm. In this case, the depth of the plurality of flocking holes 21-1B based on the flocking surface 21-1b can be, for example, 2.5 mm. The thickness of the head portion 14 is, for example, a thickness measured at a central portion of the head portion 14 in the X direction.

The two support portions 21-2 are provided so as to project from the bottom surface 21-1a of the base member main body 21-1 in the Z direction (downward in the state shown in FIG. 1). One of the two support portions 21-2 is disposed on the front end side of the base member main body 21-1, and the other is disposed on the rear end side of the base member main body 21-1. The two support portions 21-2 are arranged to face each other in the X direction. The two support portions 21-2 each have a protruding surface 21-2a that is a flat surface.
The two projecting surfaces 21-2 a are exposed from the outer surface of the first soft resin 22 and are flush with the outer surface of the first soft resin 22. That is, as shown in FIG. 3, the support portion 21-2 is exposed on the side opposite to the flocking surface 21-1b as a second exposed portion in the head portion 14.

The protruding surface 21-2a is used when the hard member 17 including the base member main body 21-1 is molded using the first mold 41 shown in FIG. 11 described later (see FIG. 11). This is the part that comes into contact with the inner surface of
As described above, when the protruding surface 21-2a comes into contact with the inner surface of the first mold 41 (see FIG. 11), the first soft resin 22 is provided around the two support portions 21-2 and on the bottom surface 21-1a. Can be formed.

That is, the amount of protrusion of the two support portions 21-2 (in other words, the distance to the protrusion surface 21-2a based on the bottom surface 21-1a) is equal to the first soft resin 22 disposed on the bottom surface 21-1a. In the Z direction.
Therefore, the protrusion amount of the two support portions 21-2 can be appropriately set according to the thickness of the first soft resin 22 disposed on the bottom surface 21-1a. When the thickness of the head portion 14 in the Z direction is 5.0 mm and the thickness of the base member main body 21-1 in the Z direction is 4.2 mm, the protrusion amount of the two support portions 21-2 is, for example, 0 mm. .8 mm. The thickness of the head portion 14 and the base member main body 21-1 is, for example, a thickness measured at a central portion of the head portion 14 in the X direction.

  1 and 3, the case where the number of the support portions 21-2 is two has been described as an example, but the number of the support portions 21-2 may be one or more, and is not limited to two.

The base member 21 having the above-described configuration has a rear end integrally formed with a front end portion of the core portion 25 (one end of the core portion 25).
As the hard resin forming the base member 21, a resin harder than the first soft resin 22 is used. Specifically, as the hard resin constituting the base member main body 21-1, for example, a resin having a flexural modulus (JIS K7203) in the range of 500 to 3000 MPa can be used.

Specific examples of such a hard resin include, for example, polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene dimethylene terephthalate (PCT), polyacetal (POM), and polystyrene (PS). Acrylonitrile-butadiene-styrene resin (ABS), cellulose propionate (CP), polyarylate, polycarbonate, acrylonitrile-styrene copolymer resin (AS), etc., among which polybutylene terephthalate (PBT) is preferred. preferable.
Since polybutylene terephthalate (PBT) has a high breaking strength, it is possible to prevent the base member 21 from breaking or partly missing. The above hard resins may be used alone or in combination of two or more as appropriate.

The first soft resin 22 has the flocked surface 21-1b, the plurality of flocked holes 21-1B, and the end surface 21-2a of the two support portions 21-2 exposed, and the side surface of the base member main body 21-1 and It is provided so as to cover the bottom surface 21-1a.
Thus, the first soft resin 22 is disposed so as to cover the tip 21-1A of the base member main body 21-1.

  By arranging the first soft resin 22 so as to cover the distal end 21-1A of the base member main body 21-1 in this manner, when the user uses the toothbrush 10, it is disposed at the distal end 21-1A. Since the first soft resin 22 functions as a cushion material, an external force is applied in a direction from the rear end side to the front end side of the toothbrush 10, and the first soft resin 22 disposed at the front end portion 21-1 </ b> A is removed. Damage to the user's oral cavity when strongly pressed into the user's oral cavity can be suppressed.

  The thickness of the first soft resin 22 disposed on the side surface and the bottom surface 21-1a of the base member main body 21-1 may be appropriately set within a range of 0.2 to 2.0 mm depending on the purpose, for example. Although possible, it can be, for example, 0.8 mm.

  1 to 3, as an example, the case where the first soft resin 22 is provided so as to cover the side surface and the bottom surface 21-1a of the base member main body 21-1 has been described as an example. The soft resin 22 may be disposed so as to cover at least the tip 21-1A of the base member main body 21-1.

As the first soft resin 22, for example, a soft resin having a hardness of JIS K 7215 Shore A of 90 or less may be used. Examples of such a soft resin include elastomer resins such as polyolefin-based elastomer, styrene-based elastomer, and polyester-based elastomer. Among them, styrene-based elastomer is preferable from the viewpoint of weldability with polypropylene (PP). .
Specific examples of the styrene-based elastomer include, for example, Septon (trade name) manufactured by Kuraray Co., Ltd., and Rheosomer (trade name) manufactured by Riken Technos Co., Ltd.

The first soft resin 22 may be appropriately selected according to the type of the hard resin that forms the base member 21.
Specifically, when polypropylene (PP) is used as the hard resin forming the base member 21, the first soft resin 22 is preferably, for example, a polyolefin-based elastomer or a styrene-based elastomer, and more preferably a styrene-based elastomer. .
By setting the combination of the hard resin and the first soft resin 22 constituting the base member 21 to the above-described combination, it is possible to sufficiently secure the adhesion between the base member 21 and the first soft resin 22. it can.

The length (length in the X direction) of the head portion 14 having the above-described configuration is not particularly limited, and is, for example, preferably in a range of 10 to 30 mm, and more preferably in a range of 12 to 28 mm.
When the length of the head portion 14 is 10 mm or more, a sufficient area of the flocked surface 21-1b on which the hair bundle 12-1 can be planted can be secured. When the length of the head portion 14 is 30 mm or less, the operability of the toothbrush 10 in the oral cavity can be improved.

The width of the head portion 14 having the above-described configuration (the maximum width of the head portion 14 in the Y direction) is not particularly limited, and is, for example, preferably in the range of 7 to 13 mm, and more preferably in the range of 8 to 12 mm.
When the width of the head portion 14 is 7 mm or more, it is possible to sufficiently secure the area of the flocking surface 21-1b on which the bristle bundle 12-1 is planted.
Further, when the width of the head portion 14 is 13 mm or less, the operability of the toothbrush 10 in the oral cavity can be improved.

Here, with reference to FIG. 2, the position of the boundary between the rear end of the head portion 14 and the front end of the neck portion 15 and the position of the boundary between the rear end of the neck portion 15 and the front end of the handle portion 16 will be defined.
In the present invention, between the flocking surface 21-1b and the handle portion 16, the neck portion includes a portion having the same width in the Y direction as the maximum width of the head portion 14 or smaller than the maximum width of the head portion 14.
In the present embodiment, in the X direction from the front end of the head portion 14 to the rear end of the handle portion 16, the width in the Y direction is reduced, the amount of change in the width is increased, and the change in the width in the Y direction is short. A position where the amount is almost zero is defined as a boundary position between the rear end of the head portion 14 and the front end of the neck portion 15.
Further, in the X direction from the tip of the neck portion 15 to the rear end of the handle portion 16, the width in the Y direction is widened, the amount of change in the width is large, and eventually the amount of change in the width in the Y direction is almost zero. Is the position of the boundary between the rear end of the neck portion 15 and the front end of the handle portion 16.
In the present invention, the rear end side of the handle portion 16 of the flocking hole disposed at the position furthest away from the front end of the head portion 14 in the X direction from the front end of the head portion 14 is referred to as the rear end of the head portion 14. The position of the boundary with the tip of the neck portion 15 may be used.
The length of the neck portion 15 in the X direction can be appropriately set within a range of, for example, 20 to 60 mm. In this case, the total length of the head portion and the neck portion is, for example, 40 It can be set appropriately within a range of up to 85 mm.

  The neck part 15 is a part that connects the head part 14 and the handle part 16. The width of the neck 15 in the Y direction is configured to be smaller than the width of the head 14 and the handle 16. The thickness of the neck 15 in the Z direction can be, for example, the same as the thickness of the head 14.

The neck 15 has a core 25, which is a component of the hard member 17, and a soft part 26.
The core portion 25 extends in the X direction (the direction in which the neck portion 15 extends) and extends through the neck portion 15 with a first portion 25-1 and extends in the X direction with one end being a first portion. 25-1 and a second portion 25-2 disposed on a part of the handle portion 16.
Here, the first portion 25-1 of the neck portion 15 will be described, and the second portion 25-2 will be described when describing the configuration of the handle portion 16.

  FIG. 8 is a cross-sectional view of the hard member (specifically, the first portion) shown in FIG. 8, the same components as those of the structure shown in FIGS. 1 to 6 are denoted by the same reference numerals. In FIG. 8, for convenience of description, reference numerals of components of the toothbrush 10 other than components of the hard member 17 are also illustrated. In FIG. 8, for convenience of description, reference numerals of the neck portion 15 are illustrated.

Referring to FIGS. 1 to 6 and 8, the first portion 25-1 has one end integrally formed with the rear end of the base member 21, and the other end has the second portion 25-2. And is configured integrally.
The first portion 25-1 is made of a hard resin. The first portion 25-1 is formed of a hard resin harder than the first soft resin 22 and the second soft resin 27 constituting the soft portion 26 (the flexural modulus (JIS K7203) is in the range of 500 to 3000 MPa). (A certain hard resin).

  The first portion 25-1 has the same thickness in the X direction. When a strong external force is applied to the tip of the head portion 14, the neck portion 15 is bent at the deformed portion 15A (for example, near the center of the neck portion 15) shown in FIG. 2 (in other words, the tip of the head portion 14). The thickness and shape of the first portion 25-1 and the thickness of the soft portion 26 disposed around the first portion 25-1 may be determined so that the force applied to the first portion 25-1 is released.

  Specifically, the area of the cut surface of the neck portion 15 obtained when the central portion in the X direction of the neck portion 15 is cut on a surface orthogonal to the X direction (the cut surface 25 of the first portion 25-1) -1a and the area S2 of the cut surface of the soft part 26) as 100%, the area S1 of the cut surface 25-1a of the first portion 25-1 is 5%. It is good to make it more than 50% and preferably, for example, it is good to make it 27%.

  As the shape of the first portion 25-1 when cut along a plane orthogonal to the X direction, for example, a circular shape, an elliptical shape, a square, a rectangle, a rhombus, a star shape, and the like can be used. Further, in consideration of the safety of the user, the corner of the first portion 25-1 may be formed in a round shape (round shape).

  By the way, when brushing the teeth using the toothbrush 10, the neck portion 15 moves in the Z direction (in other words, the direction in which a force is applied when the tip of the brush portion 12 is pressed against the teeth or between the teeth). It is preferable that it is not easily deformed (in other words, that the tip of the brush portion 12 can be pressed firmly between the teeth and the teeth).

  Therefore, the first width W1 of the first portion 25-1 in the Z direction (first direction orthogonal to the flocking surface 21-1b) is in the Y direction (second direction) orthogonal to the Z direction. It is preferable that the width be larger than the second width W2 of the first portion. The first width W1 is, for example, 1.5 mm to 3.0 mm, and the second width W2 is, for example, 1.5 mm to 2.0 mm.

  As described above, the cleaning performance of the toothbrush 10 is reduced by setting the first width W1 of the first portion 25-1 in the Z direction to be larger than the second width W2 of the first portion in the Y direction. Without deformation, when a strong external force is applied to the tip of the head portion 14, the head portion 14 can be bent in the Y direction at the deformed portion 15A. Thereby, since the force applied to the tip of the head portion 14 can be released, damage to the oral cavity of the user of the toothbrush 10 can be suppressed.

  In particular, when the user of the toothbrush 10 is an infant of 1 to 3 years old, the user may run while holding the toothbrush 10 in his / her mouth. In such a case, even if the infant falls down, the infant may Can be prevented from being damaged.

The sectional shape of the first portion 25-1 such that the first width W1 of the first portion 25-1 in the Z direction is larger than the second width W2 of the first portion in the Y direction is shown in FIG. For example, an ellipse, rectangle, rhombus, and the like as shown in FIG. In this case, the ellipse includes not only a curve formed from a set of points at which the sum of the distances from the two focal points is constant, but also an ellipse formed by connecting two semicircles having the same radius by two parallel tangents. .
When the first portion 25-1 having an elliptical or rhombic cross-sectional shape is used, the maximum value of the first width W1 may be configured to be larger than the maximum value of the second width W2.
In FIG. 8, when the diameter R1 of the neck portion 15 is 3.95 mm, the first width W1 can be set to, for example, 1.975 mm. At this time, the second width W2 can be, for example, 1.7 mm.

The soft part 26 is configured by a second soft resin 27 that accommodates the first part 25-1 therein and is softer than the hard resin that forms the core part 25. The soft portion 26 is a member that suppresses the first portion 25-1 from being exposed, and also causes the deformed portion 15 </ b> A of the neck portion 15 to bend when a strong force is applied to the tip of the head portion 14. It is a member for performing.
As the second soft resin 27, for example, a soft resin having a hardness of 90 or less in JIS K 6253 Shore A can be used. As such a soft resin, the soft resin exemplified when describing the first soft resin 22 can be used.

The second soft resin 27 may be made of a different kind of soft resin than the first soft resin 22 depending on the purpose. In this case, for example, the hardness of the soft resin used as the first soft resin 22 may be higher than the hardness of the soft resin used for the second soft resin 27. With such a configuration, the hardness of the tip of the head portion 14 and the hardness of the neck portion 15 can be made different.
Further, the same kind of soft resin may be used as the first and second soft resins 22 and 27. Thereby, the number of types of soft resin used when manufacturing the toothbrush 10 can be reduced.

In FIG. 8, as an example, the case where the outer shape of the cut surface of the soft part 26 is circular has been described, but the outer shape of the cut surface of the soft part 26 is not limited to this.
For example, when the first portion 25-1 in which the cut surface 25-1a shown in FIG. 8 has an elliptical shape is used, for example, a part of the major axis is a cut surface 25- An elliptical shape coinciding with the long axis of 1a or the above-mentioned elliptical shape may be used. When the cut surface 25-1a has an elliptical shape, an elliptical shape, or a polygonal shape, the diameter R1 of the neck portion 15 may be set to a value corresponding to the circumscribed circle of the cut surface 25-1a.

  Referring to FIGS. 1 to 6, the handle portion 16 includes a second portion 25-2 (a part of the core portion 25) constituting the core portion 25, and a plurality of projecting portions 29 constituting the hard member 17. , The handle body 31, the ring-shaped recesses 32-1 and 32-2 (ring-shaped recesses), the first rib 34, the second rib 35, and the third rib 37. And

FIG. 9 is a cross-sectional view of the hard member (specifically, the second portion) shown in FIG. FIG. 10 is a cross-sectional view of the hard member (specifically, the second portion) shown in FIG. 4 taken along the line DD.
9 and 10, the same components as those in the structure shown in FIGS. 1 to 6 are denoted by the same reference numerals. 9 and 10, reference numerals of the handle portion 16 are illustrated for convenience of explanation. 9 and 10, reference numerals of components of the toothbrush 10 other than components of the handle portion 16 are also illustrated for convenience of description.

  Referring to FIGS. 1 to 6, 9, and 10, the second portion 25-2 is made of a hard resin, and one end thereof is integrated with the first portion 25-1. . As the hard resin forming the second portion 25-2, for example, the same hard resin as the hard resin forming the first portion 25-1 can be used.

The second portion 25-2 has a similar shape in which a cross-sectional shape orthogonal to the X direction is continuously increased in diameter in a direction from one end of the second portion 25-2 toward the plurality of columnar protrusions 29 in the X direction. It is configured to be a shape. In other words, the second portion 25-2 is configured such that the portion where the plurality of protrusions 29 are provided has the largest diameter.
In addition, of the second portion 25-2, a portion disposed on the rear end side of the handle portion 16 with respect to the plurality of protrusions 29, as going from the plurality of protrusions 29 toward the rear end of the handle portion 16. The cross-sectional shape orthogonal to the X direction is a similar shape in which the diameter continuously decreases.

As described above, of the second portion 25-2, the shape of the portion disposed on the rear end side of the handle portion 16 with respect to the plurality of protrusions 29 is changed from the plurality of protrusions 29 to the rear end side of the handle portion 16. In the case where the same soft resin is used as the first and second soft resins 22 and 27, for example, as shown in FIG. When the soft resin is introduced into the second mold 51 from the rear end side of the second mold 51 after the hard member 17 is disposed therein, the direction toward the tip of the head portion 14 (X direction) Since the soft resin easily moves (flows), the entire hard member 17 (except for the flocking surface 21-1b and the plurality of flocking holes 21-1B) can be accurately wrapped with the soft resin.
Further, as described later, when the soft resin is introduced into the second mold 51, the position and posture of the hard member 17 in the second mold 51 change due to the introduced soft resin. Can be suppressed.

  In addition, as shown in FIG. 2, the second portion 25-2 is preferably provided inside the distal end portion of the handle portion 16, but is not limited thereto. The second portion 25-2 may be provided inside the neck portion 15, for example.

In the case of the present embodiment, four protrusions 29 are provided as an example. The four protruding portions 29 are arranged in the circumferential direction of the thickest portion of the second portion 25-2.
The angle formed by the two protrusions 29 arranged at adjacent positions can be, for example, 90 degrees. A space formed between two projecting portions 29 arranged at adjacent positions functions as a path for introducing a soft resin into a second mold 51 shown in FIG. The soft resin is supplied to the front end side of the head section 14 via the space, and solidifies (curs) to become the first soft resin 22.

Each of the plurality of protrusions 29 has a protrusion surface 29a. The protruding surfaces 29 a of the plurality of protruding portions 29 are exposed from the outer surface of the handle portion main body 31 (in other words, the outer surface of the handle portion 16) and face the outer surface of the handle portion main body 31 (the outer surface of the handle portion 16). It is configured to be one.
As shown in FIGS. 1, 2, and 10, the protrusion 29 serving as the first protrusion located on the + Z side is provided with the flocking surface 21-1b via the opening 31 a of the handle portion main body 31 (soft portion 26). Exposed to the side. The protruding portion 29 serving as the second protruding portion located on the −Z side is exposed to the side opposite to the flocking surface 21-1b via the opening 31b of the handle portion main body 31 (soft portion 26). The protruding portion 29 located on the + Y side is exposed to the + Y side via the opening 31c of the handle portion main body 31 (soft portion 26). The protruding portion 29 located on the −Y side is exposed to the −Y side via the opening 31c of the handle portion 16 (soft portion 26). As shown in FIGS. 1 and 2, the soft portion 26 of the handle portion 16 has a tapered portion 31A that tapers toward the distal end, and the openings 31a to 31d are formed in the tapered portion 31A. I have. In other words, the protruding portion 29 is exposed to the outside through the openings 31a to 31d formed in the tapered portion 31A of the handle portion 16.

  As shown in FIG. 10, since the cross-sectional shape of the outer surface of the handle portion 16 is substantially circular, the cross-sectional shape of the protruding surface 29a is arc-shaped. Therefore, each protruding surface 29a is exposed facing the outside in the radial direction, and is exposed facing the direction perpendicular to the length direction and the radial direction of the toothbrush 10. Specifically, for example, in FIG. 10, the protruding surface 29a of the protruding portion 29 as the first protruding portion located on the + Z side is exposed facing the + Z side, and is exposed facing the + Y side and the −Y side. I do. Similarly, for example, in FIG. 10, the protruding surface 29a of the protruding portion 29 serving as the second protruding portion located on the −Z side is exposed facing the −Z side, and is exposed facing the + Y side and the −Y side. I do.

  The plurality of protruding portions 29 are used to dispose the hard member 17 in the space 53 of the second mold 51 by using the second mold 51 (see FIG. 12) to mold the handle portion main body 31. When the protruding surface 29a comes into contact with the inner surface of the second mold 51, it has a function of maintaining the attitude of the hard member 17 in the space together with the two support portions 21-12 constituting the base member 21 (details are described in detail below). See below). In a state where the hard member 17 is accommodated in the second mold 51, the four protruding portions 29 come into contact with the inner surface of the second mold 51 when the protruding surfaces 29 a contact the hard member 17 from four directions. Support the rear end of

The protrusion amount of the plurality of protrusions 29 is equal to the thickness of the second soft resin 27 disposed around the plurality of protrusions 29. Therefore, the protrusion amount of the plurality of protrusions 29 is flush with the surface of the second soft resin 27 according to the desired thickness of the second soft resin 27 disposed around the plurality of protrusions 29. The value can be set appropriately.
In FIG. 10, when the diameter R2 of the second portion 25-2 is 5.6 mm, the protrusion amount T1 of the plurality of protrusions 29 can be, for example, 1.77 mm.

In FIGS. 1 to 6 and FIG. 10, as an example of the plurality of protrusions 29, the case where four protrusions 29 are provided has been described, but the number of the plurality of protrusions 29 is four. It is not limited to.
For example, the number of the plurality of protruding portions 29 may be, for example, three (in this case, the protruding portions 29 arranged at adjacent positions are arranged so that the angle formed by the protruding portions 29 is 120 degrees), or two or more and eight. No more than three.
Further, the shape of the plurality of protrusions 29 may be any shape as long as the shape has a flow path through which the soft resin can flow from the rear ends of the plurality of protrusions 29 to the front end of the base member 21. 6 and FIG. 10 are not limited to the columnar shape. The cross-sectional shape of the plurality of columnar protrusions 29 may be, for example, a star shape or a heart shape having excellent design.

Referring to FIGS. 1 to 3, the handle portion main body 31 is a portion that the user of the toothbrush 10 grasps by hand, and is made of the second soft resin 27.
As described above, by forming the handle portion main body 31 from the second soft resin 27, a strong external force is applied in a direction from the rear end of the toothbrush 10 to the front end of the head portion 14 with the toothbrush 10 held in the mouth. Then, the handle portion main body 31 can be deformed (specifically, bent).
As a result, not only the neck portion 15 but also the handle portion main body 31 is bent, so that an external force from the rear end of the toothbrush 10 toward the front end of the head portion 14 can be released in a different direction. Damage to the oral cavity of the ten users can be suppressed.

  In addition, by configuring the handle portion main body 31 using the second soft resin 27, even when a strong force is applied to the handle portion main body 31, the handle portion 16 is damaged (in other words, the handle portion 16 is damaged). Is broken) can be suppressed.

The ring-shaped recesses 32-1 and 32-2 are provided annularly over the entire circumferential direction of the handle portion main body 31. The ring-shaped recessed portion 32-1 is disposed on the rear end side of the handle portion 16 with respect to the disposition position of the second portion 25-2. The ring-shaped recessed portion 32-1 is configured by reducing the diameter of the handle portion main body 31. That is, the ring-shaped recessed portion 32-1 has a cross-sectional shape orthogonal to the X direction similar to the handle portion main body 31, and has a shape in which the diameter is continuously reduced.
The ring-shaped recessed portion 32-2 is disposed, for example, at a distance of 20 mm to 50 mm on the rear end side of the handle portion 16 from the position where the ring-shaped recessed portion 32-1 is provided. The ring-shaped recess 32-2 is configured by reducing the diameter of the handle body 31. That is, the ring-shaped recessed portion 32-2 has a cross-sectional shape orthogonal to the X direction similar to the handle portion main body 31, and has a shape in which the diameter is continuously reduced.

As described above, by disposing the ring-shaped recesses 32-1 and 32-2 formed by reducing the diameter of the handle portion main body 31 in the X direction of the handle portion main body 31, the toothbrush 10 can be held in the mouth. When a strong external force is applied in the direction from the rear end of the toothbrush 10 toward the front end of the head portion 14 in the held state, the ring-shaped recessed portions 32-1 and 32-2 as the second deformed portions are disposed at the positions. Thus, the handle portion 16 can be easily bent.
As a result, the external force applied in the direction from the rear end of the toothbrush 10 toward the front end of the head portion 14 can be more efficiently released in a different direction from the external force, so that the oral cavity of the user of the toothbrush 10 is damaged. Can be further suppressed.

  In addition, the user uses the toothbrush 10 by arranging the ring-shaped depressions 32-1 and 32-2 formed by reducing the diameter of the handle portion main body 31 in the X direction of the handle portion main body 31. In doing so, the handle portion 16 can be easily held, so that the operability of the toothbrush 10 can be improved.

1 to 3, the case where two ring-shaped recessed portions 32-1 and 32-2 are provided in the handle portion body 31 has been described as an example, but the ring-shaped recessed portions 32-1 and 32-2 are described. The number of 2 is not limited to two. The number of the ring-shaped recessed portions 32-1 and 32-2 may be one or more and five or less as needed.
Also, the arrangement positions of the ring-shaped recessed portions 32-1 and 32-2 may be provided on the handle portion main body 31 located behind the arrangement position of the second portion 25-2. The position is not limited to the arrangement of the ring-shaped depressions 32-1 and 32-2 shown in FIG.

The plurality of first rib portions 34 are arranged on a portion of the ring-shaped recessed portion 32-1 that forms a side surface (in other words, two side surfaces) of the handle portion main body 31.
A plurality of the second rib portions 35 are arranged on a portion of the ring-shaped recessed portion 32-2 that forms a side surface (in other words, two side surfaces) of the handle portion main body 31.
The plurality of third rib portions 37 are arranged on the side surface (in other words, two side surfaces) of the handle portion main body 31 located on the rear end side of the position where the second rib portion 35 is provided.
The first to third rib portions 34, 35, 37 can be made of the second soft resin 27. In this case, the first to third rib portions 34, 35, 37 can be formed at a time when the handle portion main body 31 is formed.
The first to third rib portions 34, 35, 37 are not always necessary.

  Thus, the plurality of first ribs 34 arranged in the ring-shaped recess 32-1, the plurality of second ribs 35 arranged in the ring-shaped recess 32-2, and the second rib By having the plurality of third ribs 37 disposed on the side surface of the handle portion main body 31 located on the rear end side from the disposition position of the handle 35, the finger holding the toothbrush 10 becomes less slippery. The grip performance of the main body 31 can be improved.

Referring to FIG. 1, the brush unit 12 is configured by a hair bundle 12-1 planted in a plurality of planted holes 21-1B provided in the base member 21. The hair bundle 12-1 is a bundle of a plurality of hairs.
The length (hair length) of the hair bundle 12-1 on the basis of the planted surface 21-1b can be determined in consideration of the hair length and the like required for the hair bundle 12-1. Specifically, the length (hair length) of the hair bundle 12-1 can be appropriately set, for example, within a range of 6 to 13 mm.

The hair bundle 12-1 may be composed of, for example, a plurality of hairs with uniform hair lengths or a plurality of hairs with different lengths.
FIG. 1 illustrates a case where the tips of a plurality of bristle bundles 12-1 forming the brush unit 12 are aligned as an example of the brush unit 12 forming the toothbrush 10, but the present invention is not limited thereto.
For example, a step may be provided in the brush part 12 by making the lengths of the plurality of bristle bundles 12-1 constituting the brush part 12 different.

The thickness (hair bundle diameter) of the hair bundle 12-1 can be determined in consideration of the hair stiffness and the like required for the hair bundle 12-1, and may be appropriately set, for example, within a range of 1 to 2 mm. it can.
All the hair bundles 12-1 may have the same hair bundle diameter or may be different from each other.

The plurality of hairs constituting the hair bundle 12-1 are, for example, tapered hairs whose diameters become smaller toward the hair tips and are sharpened, or hair tips from the flocking surface 21-1b. For example, straight bristles, which are bristles whose diameters are substantially the same, can be used.
Further, as the straight bristles, for example, bristles having a flat surface substantially parallel to the flocked surface 21-1b, or bristles having a bristle tip that is rounded into a hemisphere can be used.

The material of the hair constituting the hair bundle 12-1 is, for example, polyamide such as 6-12 nylon (6-12NY), 6-10 nylon (6-10NY), PET, PBT, polytrimethylene terephthalate (PTT). And polyester materials such as polyethylene naphthalate (PEN) and polybutylene naphthalate (PBN), and resin materials such as polyolefin such as PP.
The above-mentioned resin material used as the material for the hair may be used alone or in combination of two or more.

In addition, as the hair constituting the hair bundle 12-1, for example, polyester hair having a multi-core structure having a core portion and at least one or more sheath portions provided outside the core portion. May be used.
The cross-sectional shape of the hair constituting the hair bundle 12-1 is not particularly limited, and may be, for example, a circle such as a perfect circle or an ellipse, a polygon, a star, a three-leaf clover shape, or a four-leaf clover shape. Can be used.
The cross-sectional shapes of all the bristles constituting the brush portion 12 may be the same or different.

The thickness of the hair constituting the hair bundle 12-1 can be determined in consideration of the material of the hair and the like. When the cross section of the hair is circular, the thickness of the hair can be, for example, 6 to 9 mil. One mil is 0.0254 mm.
In addition, the hair bundle 12-1 may be configured by arbitrarily combining a plurality of hairs having different thicknesses in consideration of a feeling of use, a feeling of brushing, a cleaning effect, durability, and the like.

  According to the toothbrush of the present embodiment, at least the tip portion is made of the first soft resin 22 and the head portion 14 having the flocking surface 21-1b and the handle portion main body 31 made of the second soft resin 27 And a neck portion 15 connecting the head portion 14 and the handle portion 16. The neck portion 15 extends in the extending direction (X direction) of the neck portion 15, and A core portion 25 made of a hard resin harder than the first soft resin 22 and a soft portion 26 containing the core portion 25 therein and made of a second soft resin 27 softer than the hard resin; By including the second soft resin 27 as a component when a strong external force is applied in a direction from the rear end of the toothbrush 10 toward the front end of the head portion 14 with the user holding the toothbrush 10 to the mouth. Neck 15 and handle 6 is deformed (specifically, bent), the force transmitted to the tip of the head 14 can be released, and the soft first soft resin 22 disposed at the tip of the head 14 is removed. Since it becomes possible to contact the inside of the mouth of the user, it is possible to prevent the inside of the mouth of the user of the toothbrush 10 from being damaged.

  In particular, when the user of the toothbrush 10 is an infant of 1 to 3 years old, the user may run while holding the toothbrush 10 in his / her mouth. In such a case, even if the infant falls down, the infant may Can be prevented from being damaged.

  In this embodiment, the case where the hard member 17 having the base member 21, the core portion 25, and the plurality of protrusions 29 is used as a component of the toothbrush 10 has been described as an example. The toothbrush (hereinafter, referred to as “toothbrush Q” for convenience of description) may be configured using a hard member (hereinafter, referred to as “hard member P” for convenience of description) excluding 21 from the constituent elements. In this case, The same effect as that of the toothbrush 10 of the present embodiment can be obtained.

In this case, the hard member P may be configured to have not only the plurality of protrusions 29 only on the rear end side of the core 25 but also the plurality of protrusions 29 on the front end side of the core 25.
With such a configuration, when a soft resin (resin that becomes the first and second soft resins 22 and 27) is introduced into a mold (not shown) having a space corresponding to the outer shape of the toothbrush Q. In addition, since the posture (position) of the hard member P in the mold can be maintained, the toothbrush Q can be manufactured with high accuracy.
When manufacturing the toothbrush Q (specifically, when implanting a bristle bundle), an in-mold method may be used.

FIG. 11 is a cross-sectional view illustrating a manufacturing process of the toothbrush according to the present embodiment, which is a diagram illustrating a process of forming a hard member using the first mold. FIG. 12 is a cross-sectional view illustrating a manufacturing process of the toothbrush according to the present embodiment, for illustrating a process of forming a first soft resin, a soft portion, and a handle main body using a second mold. FIG.
11 and 12, the same components as those of the structure shown in FIGS. 1 to 10 are denoted by the same reference numerals. The arrow shown in FIG. 11 indicates the direction in which the hard resin is introduced, and the arrow shown in FIG. 12 indicates the direction in which the soft resin (soft resin N described later) is introduced.

Next, a method of manufacturing the toothbrush 10 of the present embodiment will be described mainly with reference to FIGS. 1, 11, and 12.
Here, the following description will be given by taking as an example a case where the same kind of soft resin (hereinafter, referred to as “soft resin N”) is used as the first and second soft resins 22 and 27. Do.

First, in a process shown in FIG. 11, a space 43 corresponding to the shape of the hard member 17 is formed inside the space 43, and an introduction for introducing a hard resin into the space 43 is made up of a pair of molds 41-1 and 41-2. A first mold 41 having a mouth 45 is prepared.
A protrusion (not shown) for forming a plurality of flocking holes 21-1B is formed on the mold 41-2. In addition, the inlet 45 is arranged on the rear end side of the space 43.

  Next, the space 43 is filled with a molten hard resin (a resin having a flexural modulus (JIS K7203) in the range of 500 to 3000 MPa) serving as a base material of the hard member 17 through the inlet 45. The hardening of the resin forms the hard member 17 in which the base member 21 including the plurality of flocking holes 21-1B and the support portion 21-2, the core portion 25, and the plurality of protrusions 29 are integrated. After that, the hard member 17 is taken out of the first mold 41.

Next, in the step shown in FIG. 12, a space 53 corresponding to the shape of the toothbrush 10 excluding the brush portion 12 shown in FIG. A second mold 51 having an introduction port 55 for introducing the mold is prepared. The joining surface of the pair of dies 51-1 and 51-2 is set at, for example, an intermediate position in the Z direction of the soft portion 26 (handle body 31) shown in FIGS.
A protrusion (not shown) for forming a plurality of flocking holes 21-1B is formed on the mold 51-2. Further, the introduction port 55 is arranged on the rear end side of the space 53.
In addition, the second mold 51 is formed with the ring-shaped recesses 32-1 and 32-2, the first rib 34, the second rib 35, and the third rib 37 shown in FIG. Projection is provided.

  Next, the hard member 17 is disposed at the end of the space 53 of the second mold 51. At this time, the inner surface of the mold 51-2 and the flocking surface 21-1b are brought into contact with each other so as to cover the plurality of flocking holes 21-1B, and the end surfaces of the two support portions 21-2 and the mold 51-1. , And furthermore, the protruding surfaces 29a of the plurality of (four in the present embodiment) protruding portions 29 and the inner surface of the second mold 51 are brought into contact.

  As a result, the soft resin N serving as the first soft resin 22 and the second soft resin 27 (the soft resin constituting the soft portion 26 and the handle portion main body 31) is placed in the space 53 of the second mold 51. When introduced, the position and orientation of the hard member 17 in the second mold 51 can be maintained.

That is, the projecting surface 29a of the projecting portion 29 located on the + Z side contacts the inner surface of the mold 51-2, and the projecting surface 29a of the projecting portion 29 located on the −Z side contacts the inner surface of the mold 51-1. Thereby, the hard member 17 is positioned in the Z direction. Further, since the projecting surface 29a of the projecting portion 29 located on the + Z side and the projecting portion 29 located on the -Z side face the + Y side and the -Y side, respectively, the mold 51-1 and the mold 51 are formed. By contacting the inner surface of -2, positioning is also performed in the Y direction.
In addition, the end surfaces of the two support portions 21-2 and the protruding surfaces 29 a of the plurality of protruding portions 29 come into contact with the inner surface of the second die 51, so that the gap between the hard member 17 and the second die 51 is increased. In addition, a gap for forming the first soft resin 22 and the soft portion 26 can be secured.

Next, the space 53 is filled with the melted soft resin N (a resin having a hardness of JIS K 7215 Shore A of 90 or less) through the inlet 55.
Since the inner surfaces of the molds 51-1 and 51-2 at the positions corresponding to the tapered portions 31A taper toward each other so as to taper toward the distal end, the protruding surface 29a contacts the inner surfaces. Accordingly, the hard member 17 is prevented from moving toward the distal end. Therefore, the hard member 17 is positioned without moving in the X direction even when the resin pressure of the molten soft resin N filled through the inlet 55 is applied.
After that, by curing the soft resin N, the first soft resin 22, the soft portion 26, and the handle portion main body 31 are formed. A parting line of a minute ridge is formed on the surface of the soft portion 26 at a position (substantially at an intermediate position in the Z direction) facing the joining surface of the molds 51-1 and 51-2.
Thereby, the handle body 11 having the head portion 14, the neck portion 15, and the handle portion 16 is formed. After that, the handle body 11 is taken out of the second mold 51.

Next, as shown in FIG. 1, a hair bundle 12-1 is implanted into the plurality of hair implantation holes 21-2 of the head unit 14. Thereby, the toothbrush 10 of the present embodiment shown in FIG. 1 is manufactured.
As a method of implanting the hair bundle 12-1, for example, after the hair bundle 12-1 is folded in two, a flat wire (a thin plate made of metal (for example, brass)) is placed inside the hair bundle 12-1. Can be used to implant the hair bundle 12-1 in which the flat wire is sandwiched in the flocking hole 21-2.

  Note that, in the present embodiment, the case where the flat wire flocking method is used as a method for flocking the hair bundle 12-1 has been described as an example, but instead of this method, for example, a resin forming the head portion 14 is used. (A soft resin or a hard resin), a heat fusion method in which the lower end of the hair bundle 12-1 is press-fitted and fixed, or a lower end of the hair bundle 12-1 is heated to form a molten mass, and then the inside of the mold is formed. For example, an in-mold method of introducing a molten resin into the resin may be used.

  As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible.

For example, in the above-described embodiment, the configuration in which the soft portion 26 is provided at the distal end portion of the head portion 14 is illustrated. However, the configuration is not limited thereto. As illustrated in the side view of FIG. 13 and the front view of FIG. A configuration in which the neck portion 15 includes the deformed portion 15A and the soft portion 26 is provided on the rear end side from the deformed portion 15A may be employed.
In addition, the present invention can be widely applied to a so-called one tuft toothbrush having a single bristle bundle, a toothbrush having a tongue coating auxiliary removing portion, and the like as a toothbrush.

  In the above-described embodiment, the width in the second direction (Y direction) between the flocking surface 21-1b and the handle portion 16 is smaller than the width of the head portion 14 (maximum width in the Y direction). Although the toothbrush 10 in which the neck portion 15 is arranged has been described, the present invention is not limited to this configuration. For example, the width in the Y direction between the flocked surface 21-1b and the handle portion 16 is The present invention also includes a toothbrush in a case where the same portion as the maximum width exists. In this case, the deformed portion is arranged with the portion as a neck portion, and at least a part of the hard member is housed inside the rear end side from the deformed portion, and a soft portion formed of a soft resin is arranged. Is done.

  INDUSTRIAL APPLICATION This invention can be utilized for the toothbrush which can control the damage of a user's oral cavity.

  DESCRIPTION OF SYMBOLS 10 ... Toothbrush, 11 ... Handle body, 12 ... Brush part, 14 ... Head part, 15 ... Neck part, 15A ... Deformation part, 16 ... Handle part, 17 ... Hard member, 21 ... Base member, 21-1 ... Base member Main body, 21-1a: bottom surface, 21-1A: tip portion, 21-1b: flocking surface (first exposed portion), 21-1B: flocking hole, 21-2: support portion, 21-2a: protruding surface, 22 ... first soft resin, 25 ... core part, 25-1 ... first part, 25-1a ... cut surface, 25-2 ... second part, 26 ... soft part, 27 ... second soft resin, 29 ... projecting portion, 29a ... projecting surface, 31 ... handle portion main body, 31A ... tapered portion, 32-1, 32-2 ... ring-shaped recessed portion (second deformed portion), 34 ... first rib portion, 35 ... 2nd rib part, 37 ... 3rd rib part, 41 ... 1st metallic mold, 41-1, 41-2, 51-1 51-2: mold, 43, 53 ... space, 45, 55 ... inlet, 51 ... second mold, R1, R2 ... diameter, S1, S2 ... area, T1 ... protrusion amount, W1 ... first Width, W2 ... second width

Claims (6)

A head portion having a flocked surface on the tip side,
A handle portion disposed rearward of the head portion and including a handle portion body;
A neck connecting the head and the handle;
Has,
The neck portion contains a hard member formed of a hard resin extending in the direction in which the neck portion extends, and has a region covered with a soft resin,
An end on the rear end side of the hard member is located on a tip end side of the handle portion,
The handle portion is configured such that a rear end of the hard member on the front end side is accommodated with the soft resin, and a rear end side of the rear end of the hard member with respect to the rear end is formed of the soft resin. And
A toothbrush wherein the handle portion is bent when an external force is applied in a direction from the rear end side to the front end side.   2. The ratio of the rigid member to the area of a cut surface orthogonal to the extending direction of a central portion of the neck portion in the extending direction is 5% or more and less than 50%. The toothbrush as described.   The said neck part has the area | region where the said hard member is covered in the non-exposed state by the said soft resin in the whole circumferential direction centering on the axial line extended in the said extending direction, The Claims 1 or 2 characterized by the above-mentioned. toothbrush.   4. The toothbrush according to claim 3, wherein the hard member has a plurality of protruding portions that are exposed and protruded in a circumferential direction about the axis at a rear end side in the extending direction. 5.   The toothbrush according to claim 4, wherein the cross-sectional shape of the hard member decreases from the protruding portion toward the rear end.   The neck portion and the handle portion both bend when an external force is applied in a direction from the rear end side to the front end side, according to any one of claims 1 to 5, wherein: toothbrush.

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