KR20220029542A - toothbrush - Google Patents

Abstract

An object of the present invention is to provide a toothbrush having good operability that can reliably wipe a target area while maintaining an appropriate brushing pressure. It has a deformable portion 70 that is disposed on the gripping portion 30 and deformed by an external force in a first direction orthogonal to the hair transplantation surface 11, and a first region and a second region that are not deformed by the external force, and is deformed. The portion has a hard portion (H) formed of a hard resin connecting the first region and the second region, and a soft portion (E) formed of a soft resin and covering at least a part of the hard portion, The occupancy of the cross-sectional area of the hard part with respect to the cross-sectional area of the closed space surrounded by the extension line is 35% or less over the major axis direction, and the deformable portion has a bending strength in the first direction, the major axis direction and bending strength in the second direction orthogonal to the first direction. It is regulated smaller than that, and the soft portion has a concave and convex portion extending in a direction intersecting the major axis direction and a concave-convex structure portion 101 adjacent to each other, and the concave-convex structure portion is exposed to the hair-transplantation surface side and the back side in the first direction, respectively. is provided.

Description

toothbrush

The present invention relates to a toothbrush.

This application claims priority on June 28, 2019 based on Patent Application No. 2019-121254 for which it applied to Japan, The content is used here.

The proportion of people who have 20 teeth at the age of 80 is about 50%, while the proportion of caries in the elderly (industry caries) is increasing. Diligent caries is caries of dentin exposed by gum recession, but since dentin has a higher proportion of organic components than enamel, progress of caries is quick. As one of the causes of the said gum recession, over-brushing which brushes with the brushing pressure (cleaning pressure) larger than an appropriate value is mentioned.

Conventionally, as a toothbrush for reducing excessive brushing pressure, the toothbrush of patent document 1 is indicated, for example. The toothbrush described in Patent Document 1 is formed in a U-shape in which a portion formed of a thermoplastic resin is opened to the hair-transplantation surface side among portions gripped by the thumb and forefinger of the handle portion when brushing by gripping with a palm grip, and a thermoplastic resin The periphery of the portion formed by the slab is coated with a soft resin such as an elastomer material.

About the toothbrush of the said structure in patent document 1, by giving elasticity not only to the neck part but also to the said part of the handle part by the load of the head part, while giving comfortable operability by touching teeth and gums gently, without damaging the gums, Reducing the excessive brushing pressure is described.

Japanese Patent Laid-Open No. 2000-004944

However, in the toothbrush of patent document 1, since a neck part has flexibility in all directions, it is difficult to make a brush part stably contact a desired site|part at the time of brushing.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a toothbrush having good operability that can reliably wipe a target site while maintaining an appropriate brushing pressure.

According to the first aspect of the present invention, a head portion having a hair transplantation surface provided on the tip side in the long axis direction, a gripping portion disposed on a rear end side than the head portion, and a neck portion disposed between the hair transplantation surface and the gripping portion The head part and the neck part, at least a part of which is formed of a hard resin, is disposed in the grip part, and a deformable part deformed by an external force in a first direction perpendicular to the hair transplantation surface, and the tip of the deformable part It has a first region that is not deformed by the external force in the first direction, and a second region that is not deformed by the external force in the first direction, and is disposed on the rear end of the deformable part, and is not deformed by the external force in the first direction. a portion is formed of the hard resin at least in part in a cross section orthogonal to the long axis direction from the tip of the gripping portion to the second region in the long axis direction, and the deformable portion includes the first region and the The hard part formed of the hard resin connecting the second region, and the soft part formed of the soft resin and covering at least a part of the hard part, the outline of the deformable part in a cross section orthogonal to the long axis direction or the The occupancy of the cross-sectional area of the hard part with respect to the cross-sectional area of the closed space surrounded by the extension line of the outline is 35% or less over the major axis direction, and the deformable portion has a bending strength in the first direction, the major axis direction and the first The soft portion has a concave-convex structure portion in which a concave portion and a convex portion extending in a direction intersecting the major axis direction are disposed adjacent to each other in the major axis direction, wherein the soft portion is regulated to be smaller than the bending strength in a second direction orthogonal to the major axis direction; The structure part is exposed to the said hair-transplantation surface side of the said 1st direction, respectively, and provided on the back side on the opposite side to the said hair-transplantation|transplantation surface side of the said 1st direction, The toothbrush characterized by the above-mentioned is provided.

Moreover, the toothbrush which concerns on 1 aspect of the said this invention WHEREIN: The depth of the said recessed part with respect to the said convex part is 2% or more and 20% or less with respect to the maximum thickness of the said 1st direction of the said deformation|transformation part, It is characterized by the above-mentioned.

Further, in the toothbrush according to one aspect of the present invention, the deformable portion has a polygonal cross section orthogonal to the major axis direction, and the concave-convex structure portion is provided on both sides of the deformable portion in the second direction, respectively.

Moreover, the toothbrush which concerns on 1 aspect of the said this invention WHEREIN: The outermost outermost of the said 2nd direction of the said deformation|transformation part is located in the said back side rather than the center position of the said 1st direction of the said deformation|transformation part, It is characterized by the above-mentioned.

Further, in the toothbrush according to one aspect of the present invention, the deformable portion branches in the second direction through a through hole that penetrates in the first direction and extends in the long axis direction, and each of the branched deformable portions is , characterized in that it has a core portion that branches through the through hole to connect the first region and the second region, and a covering portion that branches through the through hole and covers the periphery of the core portion. do.

Further, in the toothbrush according to one aspect of the present invention, the hard part has an inverted part that is spaced apart from the core part and penetrates the through hole in the long axis direction to connect the first region and the second region, The inversion unit is characterized in that the rain buckles and reverses when the external force in the first direction exceeds a threshold value.

Moreover, the toothbrush which concerns on 1 aspect of the said this invention WHEREIN: The said hard part is flat plate shape, and the length of the said 2nd direction of the said hard part is larger than the length of the said 1st direction of the said hard part, It is characterized by the above-mentioned.

Moreover, the toothbrush which concerns on 1 aspect of the said this invention WHEREIN: The center of the said 1st direction of the said hard part is located in the said back side rather than the center position of the said 1st direction of the said deformation|transformation part, It is characterized by the above-mentioned.

Moreover, the toothbrush which concerns on 1 aspect of the said this invention WHEREIN: The length of the said long-axis direction of the said deformation part is 15 mm or more and 30 mm, It is characterized by the above-mentioned.

Moreover, the toothbrush which concerns on 1 aspect of the said this invention WHEREIN: The length of the said 2nd direction of the said deformation part is 5 mm or more and 20 mm or less, It is characterized by the above-mentioned.

In the present invention, it is possible to provide a toothbrush capable of accurately cleaning teeth one by one while maintaining an appropriate brushing pressure.

1 : is a figure which shows embodiment of this invention, and is a front view of the toothbrush 1 which concerns on 1st Embodiment.
2 : is sectional drawing which cut the same toothbrush 1 by the plane containing the center of the width direction.
3 : is sectional drawing orthogonal to the long-axis direction in the vicinity of the long-axis direction edge part in the deformation|transformation part 70. As shown in FIG.
4 is a cross-sectional view of the deformable portion 70 cut in a plane including a center in the width direction.
5 is a partial front view of the periphery of the deformable portion 70 in the hard portion 70H.
6 is a partial side view of the periphery of the deformable portion 70 in the hard portion 70H.
7 : is a front view of the toothbrush 1 which concerns on 2nd Embodiment.
8 : is sectional drawing which cut the same toothbrush 1 by the plane containing the center of the width direction.
9 : is sectional drawing orthogonal to the long-axis direction at the center of the long-axis direction in the deformation|transformation part 70. As shown in FIG.
10 is a cross-sectional view of the deformable portion 70 cut in a plane including a center in the width direction.
11 is a partial front view of the periphery of the hard portion 70H in the deformable portion 70 .
12 is a cross-sectional view of the deformable portion 70 cut in a plane parallel to the thickness direction and the major axis direction for explaining that the inversion portion is inverted.

[First embodiment]

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of the toothbrush of this invention is demonstrated with reference to FIGS. 1-6.

In addition, the following embodiment shows one aspect|mode of this invention, does not limit this invention, It can change arbitrarily within the scope of the technical idea of this invention. In addition, in the following drawings, in order to make each structure easy to understand, the scale, the number, etc. in an actual structure and each structure are made different. In addition, in the following description, the side orthogonal to a hair-transplantation surface is made into the thickness direction, and the side opposite to the front side and a hair-transplantation surface is made into the back side for the hair-transplantation surface side in a thickness direction, and it demonstrates suitably.

1 is a front view of the toothbrush 1 . 2 : is sectional drawing which cut|disconnected the toothbrush 1 by the plane containing the center of the width direction (the up-down direction in FIG. 1).

The toothbrush 1 of this embodiment is arrange|positioned at the front-end|tip side (henceforth simply referred to as a front-end|tip side) of the long-axis direction, the head part 10 in which the hair|bristle bundle (not shown) of the hair was transplanted, and the head part 10 ) of the neck portion 20 extended to the rear end side (hereinafter simply referred to as the rear end side) of the long axis direction, and the grip portion 30 (hereinafter referred to as the rear end side) extending to the rear end side of the neck portion 20 and having a deformable portion 70 , the head portion 10, the neck portion 20, and the grip portion 30 are collectively referred to as a handle body 2).

The toothbrush 1 of this embodiment is the molded object by which the hard part H formed from hard resin, and the soft part E formed from soft resin were integrally shape|molded. The hard part H constitutes at least a part of each of the holding part 30 including the head part 10 , the neck part 20 , and the deformable part 70 . The soft portion E constitutes a part of the gripping portion 30 including the deformable portion 70 . In more detail, although the head part 10 and the neck part 20 of this embodiment are each formed from hard resin, for example, a part of the surface is covered with the said soft resin, etc., and a part is said soft resin. It may be formed from resin. A part of the holding part 30 including the deformable part 70 of this embodiment is formed in both hard resin and soft resin, respectively (details are mentioned later).

[Head (10)]

The head part 10 has the hair-transplantation surface 11 in one side of the thickness direction (direction orthogonal to the paper surface in FIG. 1). In addition, hereinafter, the direction orthogonal to the thickness direction and the major axis direction is referred to as a width direction (or an appropriate, lateral direction). In the hair-transplantation|transplantation surface 11, the plurality of hair-transplantation holes 12 are formed. In the hair-transplantation hole 12, hair bundles (not shown) of the hair are planted.

The width of the head portion 10, that is, the length in the width direction parallel to the hair transplantation surface 11 on the front side and orthogonal to the major axis direction (hereinafter simply referred to as width) is not particularly limited, for example, 7 mm or more and 13 mm or less are preferable. If it is more than the said lower limit, the area to plant a hair|hair bundle can fully be ensured, and if it is below the said upper limit, the operability in an oral cavity can be further improved.

The length (hereinafter simply referred to as length) in the major axis direction of the head portion 10 is not particularly limited, and for example, 10 mm or more and 33 mm or less are preferable. If the length of the head portion 10 is equal to or greater than the lower limit, an area for planting the hair bundle can be sufficiently secured, and if it is less than or equal to the upper limit, operability in the oral cavity can be further improved. In addition, as for the boundary of the long-axis direction of the neck part 20 and the head part 10 in this embodiment, toward the head part 10 direction from the neck part 20, the width|variety of the neck part 20 is minimum. to the position of When the region where the width of the neck portion 20 becomes the minimum value exists with a constant length (when the position where the width of the neck portion 20 becomes the minimum value is not one place), the neck portion 20 and the head portion 10 ), the boundary in the long axis direction is the position on the most head tip side where the width of the neck portion 20 becomes the minimum value.

The length of the head part 10 in the thickness direction (hereinafter simply referred to as thickness) can be determined in consideration of the material or the like, and is preferably 2.0 mm or more and 4.0 mm or less. When the thickness of the head unit 10 is equal to or greater than the lower limit, the strength of the head unit 10 may be further increased. When the thickness of the head part 10 is below the said upper limit, while being able to improve the reachability to the inside of a molar, the operability in an oral cavity can be further improved.

A hair bundle is a bundle of plural hairs. The length (hair length) from the hair-transplantation surface 11 to the front-end|tip of a hair|bristle bundle can take into consideration the hair elasticity etc. requested|required for a hair|bristle bundle, and can be determined, for example, is set to 6-13 mm. All the hair bundles may have the same hair length or may be different from each other.

The thickness (hair bundle diameter) of the hair bundle can be determined in consideration of the hair elasticity required for the hair bundle, for example, it is set to 1 to 3 mm. All the hair bundles may have the same hair bundle diameter or may be different from each other.

As the hair constituting the hair bundle, for example, hair whose diameter gradually decreases toward the tip of the hair (tapered hair), and the hair whose diameter is substantially the same from the hair implantation surface 11 toward the tip (straight hair). and the like. As a straight hair, the thing which became a plane substantially parallel to the hair-transplantation|flocking surface 11 with a bristle tip, and the thing in which the bristle tip became round in hemispherical shape is mentioned.

The material of the hair is, for example, polyamide, such as 6-12 nylon (6-12NY) and 6-10 nylon (6-10NY), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytri Elastomer resins such as polyester such as methylene terephthalate (PTT), polyethylene naphthalate (PEN), and polybutylene naphthalate (PBN), polyolefin such as polypropylene (PP), polyolefin elastomer, and styrene elastomer. there is. These resin materials can be used individually by 1 type or in combination of 2 or more type. Moreover, as hair, the hair made from polyester which has a multi-center structure which has a core part and at least one layer or more sheath part provided on the outer side of this core part is mentioned.

The cross-sectional shape of the hair is not particularly limited, and may be a circular shape such as a perfect circle or an ellipse, a polygonal shape, a star shape, a three leaf clover shape, a four leaf clover shape, or the like. The cross-sectional shape of all the hairs may be the same or different.

The thickness of the hair can be determined in consideration of the material and the like, and when the cross section is circular, for example, 6 to 9 mils (1 mil = 1/1000 inch = 0.025 mm). In addition, in consideration of a feeling of use, a feeling of cleaning, a cleaning effect, durability, etc., you may use it combining arbitrarily combining the several features from which thickness differs.

[Neck (20)]

It is preferable that the length of the neck part 20 is 40 mm or more and 70 mm or less from the point of operability.

The width of the neck portion 20 is formed so as to gradually increase from the position of the minimum value to the rear end side as an example. The neck part 20 in this embodiment is formed so that it may become large gradually from the position used as a width|variety to a minimum value toward a rear-end side. Moreover, the neck part 20 is formed so that thickness may become large gradually from the position where it becomes the minimum toward the rear end side.

As for the neck part 20, as for the width and thickness in the position used as the minimum, 3.0 mm or more and 4.5 mm or less are preferable. If the width and thickness of the neck portion 20 at the minimum position are equal to or greater than the lower limit, the strength of the neck portion 20 can be further increased. While the performance can be improved, the operability in the oral cavity can be further improved. The width and thickness of the neck portion 20 that are formed to gradually increase from the position of the minimum value toward the rear end side can be appropriately determined in consideration of the material and the like.

The front side of the neck part 20 seen in the side direction is inclined in a direction toward the front side as it goes toward the rear end side. The back side of the neck part 20 seen in the side direction inclines in the direction which goes to the back side as it goes to the rear end side. The neck portion 20 inclines in a direction in which the distance from the center in the width direction increases toward the rear end when viewed from the front.

The boundary between the neck part 20 and the grip part 30 in this embodiment is made into the position of the front-end|tip of the neck side 20 in which the deformable part 70 mentioned later is provided. Here, the width from the neck portion 20 toward the gripping portion 30 is expanded to an arc-shaped outline from both the front view and the side view, and the position in the major axis direction where the position of the center of curvature of the arc is changed, and are matching In more detail, the boundary between the neck portion 20 and the grip portion 30 (deformation portion 70) is the major axis in which the center of curvature is changed from the outer side of the arc-shaped outline to the center side in the width direction when viewed from the front shown in FIG. 1 . It coincides with the position of the direction. In addition, the boundary between the neck part 20 and the grip part 30 (deformation part 70) is the long-axis direction in which the center of curvature changes from the outer side of the arc-shaped outline to the thickness direction center side, as seen from the side view shown in FIG. matches the location.

[Gripping part 30]

The holding part 30 is arrange|positioned along the long-axis direction. The holding part 30 has the deformable part 70 on the front-end|tip side which forms the boundary with the neck part 20. As shown in FIG. As shown in FIG. 1 , the width of the gripping portion 30 on the rear end side of the deformable portion 70 is gradually narrowed from the boundary with the deformable portion 70 toward the rear end, and then extends to a substantially constant length. . As shown in FIG. 2 , the thickness of the gripping portion 30 on the rear end side of the deformable portion 70 is gradually narrowed from the boundary with the deformable portion 70 toward the rear end, and then extends to a substantially constant length. . The width of the gripping part 30 gradually narrows from the boundary with the deformable part 70 toward the rear end, and then the position in the long axis direction becomes an approximately constant length, and the thickness of the gripping part 30 is the same as the deformable part 70 . The positions in the major axis direction that become approximately constant after gradually narrowing from the boundary toward the rear end are the same. The position of the rear end of the deformable part 70 in this embodiment is made into the boundary of the soft part 70E and the hard part 30H.

The holding part 30 has the soft part 31E in the center of the width direction in the front side on the rear end side rather than the rear end side edge part of the deformable part 70. As shown in FIG. The soft part 31E constitutes a part of the soft part E. The soft portion 31E gradually narrows from the rear end side end of the deformable portion 70 toward the rear end side when viewed from the front, and then extends to a substantially constant length. When seen from the front, the side edge of the soft part 31E and the side edge of the width direction outer side of the holding part 30 are formed with substantially constant distance.

The holding part 30 has a hard part 70H (refer FIGS. 2-4) provided in the deformable part 70, and the hard part 30H provided in the rear end side rather than the deformable part 70. As shown in FIG. The hard parts 30H and 70H constitute a part of the hard part H. The hard part 30H has a recessed part 31H in which the soft part 31E is embedded in the front side. The recessed portion 31H gradually narrows from the rear end of the deformable portion 70 toward the rear end when viewed from the front, and then extends in the major axis direction with a substantially constant length. A part of the soft part 31E embedded in the recessed part 31H protrudes from the hard part 30H exposed to the front side. The other soft part 31E is substantially the same height as the hard part 30H exposed on the front side.

The holding part 30 has the soft part 32E in the center of the width direction in the back side (refer FIG. 1, FIG. 2). The soft part 32E constitutes a part of the soft part E. The soft portion 32E has an outline that is substantially the same as that of the soft portion 31E when viewed from the front. That is, the soft portion 32E gradually narrows from the rear end of the deformable portion 70 toward the rear end, and then extends to a substantially constant length. When viewed from the back, the side edge of the soft portion 32E and the side edge of the grip portion 30 outside in the width direction are formed at a substantially constant distance.

The hard part 30H has the recessed part 32H (refer FIG. 2) in which a part of soft part 32E is embedded in the back side. The recessed portion 32H gradually narrows from the rear end of the deformable portion 70 toward the rear end when viewed from the rear, and then extends to a substantially constant length. A part of the soft part 32E protrudes from the hard part 30H exposed to the back side. The other soft part 32E is substantially the same height as the hard part 30H exposed on the front side.

Since the soft part 31E is provided on the front side of the grip part 30 and the soft part 32E is provided on the back side, the grip property at the time of gripping the grip part 30 is improved.

[Deformation part (70)]

The deformable portion 70 is deformed by an external force in the thickness direction orthogonal to the hair-transplantation surface 11 . The deformable part 70 connects the neck part (first area|region) 20 on the front end side and the grip part (second area|region) 30 of the rear end side. The deformable portion 70 has a hard portion 70H and a soft portion 70E. The deformable part 70 has knurling part (concave-convex structure part) 101-104, as shown in FIG.1 and FIG.2.

3 : is sectional drawing orthogonal to the long-axis direction in the deformation|transformation part 70, and is sectional drawing seen along the A-A line in FIG. 4 : is sectional drawing which cut the deformable part 70 in the plane containing the center of the width direction.

As shown in FIG. 3, in this embodiment, the periphery of the hard part 70H is coat|covered with the soft part 70E. It is preferable that the maximum length of the major axis direction of the deformable part 70 is 15 mm or more and 30 mm or less. By setting the maximum length of the deformable part 70 in the major axis direction to 15 mm or more, it becomes possible to sufficiently feel the deformation of the deformable part 70 when the user grips the gripping part 30 . Moreover, by making the maximum length of the major axis direction of the deformable part 70 into 30 mm or less, it can suppress that the deformable part 70 bends too much easily. Moreover, it is suppressed that the deformation|transformation area|region in the gripped part is limited and operability falls.

The deformable portion 70 is a polygon in which the outline of a cross section orthogonal to the major axis direction is eccentric to the back side in the thickness direction. The cross-sectional outline of the deformable portion 70 is a substantially hexagonal outline of the soft portion 70E in which the hard portion 70H is embedded. Of the six vertices in the outline, two vertices arranged in the middle (both ends in the width direction) in the thickness direction are arranged on the back side of the center of the deformable portion 70 (soft portion 70E) in the thickness direction. By arranging the two vertices on the back side rather than the center of the thickness direction of the deformable part 70, the back side becomes thinner than the front side, and the deformable part 70 becomes easy to bend toward the back side.

Moreover, since the vertices with the same position in the thickness direction are arrange|positioned at both ends in the width direction, the bending resistance in the width direction is large at the point where the thickness at the said apex position is large. Therefore, the deformation|transformation part 70 is hard to bend in the width direction.

The cross-sectional shape of the hard part 70H is formed in the rectangular shape extending in the width direction, the width is larger than the thickness, as shown in FIG. The hard part 70H has a bending behavior (anisotropy with respect to bending) that, since the width is larger than the thickness, it is easy to bend in the thickness direction and becomes difficult to bend in the width direction. In other words, the deformable portion 70 has a hard portion 70H formed in a rectangular cross-section extending in the width direction whose width is greater than the thickness, so that the bending strength in the thickness direction is regulated to be smaller than the bending strength in the width direction. there is.

The central position of the hard portion 70H in the thickness direction is disposed on the back side of the deformable portion 70 in the thickness direction. That is, the hard part 70H is arranged eccentrically on the back side with respect to the thickness direction.

In a cross section orthogonal to the major axis direction, the occupation ratio of the cross-sectional area of the hard portion 70H to the cross-sectional area of the closed space surrounded by the outline of the deformable portion 70 or the extension line of the outline is 35% or less in the major axis direction . As the outer contour of the deformable portion 70 is shown in FIG. 3 , when a closed space is formed, the area of the closed space is the cross-sectional area of the deformable portion 70 . By setting the occupancy of the cross-sectional area of the hard portion 70H to be 35% or less of the cross-sectional area of the deformable portion 70 in the major axis direction, the bending strength of the deformable portion 70 with respect to the back side can be reduced. Electricity occupancy becomes like this. Preferably it is 25 % or less, More preferably, it is 15 % or less. Moreover, it is preferable that the said occupancy rate is 3 % or more.

The knurling portions 101 to 104 are respectively exposed and provided on the side edges of the front side, the back side, and both sides of the width direction in the deformable part 70 . In more detail, the knurling part 101 is exposed to the soft part 70E of the front side in the deformable part 70, and is provided. The knurling part 102 is exposed to the soft part 70E of the back side in the deformable part 70, and is provided.

As shown in FIG. 1 , the knurling portions 101 and 102 extend in a direction intersecting the major axis direction and each have a plurality of concave portions 111 and convex portions 112 arranged adjacent to each other in the major axis direction. The recessed part 111 and the convex part 112 in this embodiment are extended in the width direction. That is, the concave portion 111 is in the shape of a groove extending in the width direction. The convex portion 112 is a projection extending in the width direction. As shown in FIG. 4, the cross section of the recessed part 111 cut|disconnected by the plane containing the center of the width direction is the circular arc shape recessed toward the center side in the thickness direction. The cross section of the convex portion 112 cut in a plane including the center in the width direction is in the shape of an arc protruding outward in the thickness direction.

By providing a plurality of concave portions 111 forming thin portions extending in the width direction on the front side and the rear side of the deformable portion 70 in the longitudinal direction, the deformable portion 70 is formed with the concave portion 111 as the center. It becomes easy to bend to a back side and a front side. Therefore, it is preferable to make the position of the recessed part 111 of a long-axis direction mutually equal in the knurling parts 101 and 102.

The depth of the concave portion 111 with respect to the convex portion 112 (distance in the thickness direction from the apex position of the convex portion 112 to the most concave position of the concave portion 111 ) is the maximum of the deformable portion 70 . It is preferable that they are 2 % or more and 20 % or less with respect to thickness. When the depth of the concave portion 111 is less than 2% with respect to the maximum thickness of the deformable portion 70 , there is a possibility that the warpage in the thickness direction of the deformable portion 70 may not be effectively expressed. When the depth of the concave portion 111 exceeds 20% with respect to the maximum thickness of the deformable portion 70 , the gripping portion 30 is easily bent and operability may be impaired. Therefore, by setting the depth of the concave portion 111 to 2% or more and 20% or less with respect to the maximum thickness of the deformable portion 70 , the deformable portion 70 is easily bent toward the back side and the front side while operability is ensured. .

Although the depth of the recessed part 111 in the knurling part 101 and the depth of the recessed part 111 in the knurling part 102 may be different, operability and the bending characteristic in the thickness direction are a front side and a back surface. From the viewpoint of making it the same from the side, it is preferable that the depth of the concave portion 111 is the same.

As the maximum width of the knurling portions 101 and 102 , that is, the maximum width of the deformable portion 70 , it is preferable that they are 8 mm or more and 20 mm or less. When the maximum width of the deformable portion 70 is less than 8 mm, the gripping portion 30 is easily bent and operability may be impaired. Moreover, when the maximum width of the deformable part 70 exceeds 20 mm, the curvature of the thickness direction of the deformable part 70 may not express effectively. Therefore, by making the maximum width of the knurling parts 101 and 102 into 8 mm or more and 20 mm or less, it becomes easy to bend the deformable part 70 to a back side and a front side in the state which ensured operability.

The arrangement pitch RP in the long axis direction of the concave portions 111 and the convex portions 112 in the knurling portions 101 and 102 is preferably 9% or more and 26% or less of the length of the deformable portion 70 in the major axis direction. . When the arrangement pitch RP is less than 9%, there is a possibility that the warpage of the deformable portion 70 is not sufficiently expressed. When the arrangement pitch RP exceeds 26%, the deformable portion 70 warps too much, possibly impairing operability. Therefore, the arrangement pitch RP in the long axis direction of the concave portions 111 and the convex portions 112 in the knurling portions 101 and 102 is set to 9% or more and 26% or less of the length of the deformable portion 70 in the long axis direction. By doing so, it becomes easy to bend the deformable part 70 to a back side and a front side in the state which ensured operability.

The knurling part 103 is exposed to the soft part 70E of the side edge part of the width direction one side (upper side in FIG. 1) in the deformable part 70, and is provided. The knurling part 104 is exposed to the soft part 70E of the side edge of the other width direction (lower side in FIG. 1) in the deformable part 70, and is provided.

As shown in Fig. 4, the knurled portions 103 and 104 each have concave portions 113 and convex portions 114 that extend in a direction intersecting the major axis direction and are arranged adjacent to each other in the major axis direction ( In FIG. 4, only the knurling part 103 is shown). The concave portion 113 and the convex portion 114 in the present embodiment extend in the thickness direction. That is, the recessed portion 113 is in the shape of a groove extending in the thickness direction. The convex portion 114 is a projection extending in the thickness direction. As shown in FIG. 1 , the concave portion 113 has an arc shape concave toward the center side in the width direction when viewed from the front. When viewed from the front, the convex portion 114 has an arc shape protruding outward in the width direction.

By providing a plurality of concave portions 113 forming thin portions extending in the thickness direction on both sides of the deformable portion 70 in the width direction in the longitudinal direction, resistance when the deformable portion 70 is bent in the thickness direction is reduced. , it is easy to bend the deformable portion 70 toward the back side and the front side. Therefore, it is preferable to make the position of the recessed part 113 of a long-axis direction mutually equal in the knurling parts 103 and 104.

The depth of the concave portion 111 with respect to the convex portion 114 (distance in the thickness direction from the apex position of the convex portion 114 to the most concave position of the concave portion 113 ) is the maximum of the deformable portion 70 . It is preferable that they are 2 % or more and 20 % or less with respect to a width|variety. When the depth of the concave portion 113 is less than 2% with respect to the maximum width of the deformable portion 70 , a decrease in resistance when the deformable portion 70 is bent in the thickness direction is small, and the thickness direction of the deformable portion 70 is small. There is a possibility that the warpage is not effectively expressed. When the depth of the concave portion 113 exceeds 20% of the maximum width of the deformable portion 70 , the gripping portion 30 is easily bent and operability may be impaired. Therefore, by setting the depth of the concave portion 113 to 2% or more and 20% or less with respect to the maximum width of the deformable portion 70 , the deformable portion 70 is easily bent toward the back side and the front side while operability is ensured. .

Although the depth of the recessed part 113 in the knurling part 103 and the depth of the recessed part 113 in the knurling part 104 may differ, operability and the bending characteristic in the width direction are one of the width directions. From the viewpoint of making the same on the side and the other side, it is preferable that the depth of the concave portion 113 is the same.

Even if it is the same as the depth of the recessed part 111 in the knurling parts 101 and 102 arrange|positioned in the thickness direction, and the depth of the recessed part 113 in the knurling parts 103 and 104 arrange|positioned in the width direction However, it is preferable that the recessed part 111 is deeper than the recessed part 113 from a viewpoint of making it easy to bend in the thickness direction.

Since the convex portions 112 and 114 are provided around the deformable portion 70 at intervals (recesses 111 and 113) in the long axis direction, the grip property when the deformable portion 70 is gripped is improved. .

As the knurling portions 101 and 102 , the direction in which the concave portion 111 and the convex portion 112 extend is limited to a flat-wood knurling structure in which the concave portion 111 and the convex portion 112 are orthogonal to the long axis direction in which they are arranged. doesn't happen When the intersection angle between the extending direction and the arranging direction of the concave portion 111 and the convex portion 112 is other than 90 degrees, the extending direction and the major axis direction of the concave portion 111 and the convex portion 112 are The first knurling group intersected at one angle and arranged in the major axis direction, the direction in which the concave portion 111 and the convex portion 112 extend and the major axis direction are line symmetric with the first angle with the major axis direction as the center You may employ|adopt the ridge knurling structure in which the 2nd knurling group which intersects at a 2nd angle and is arranged in a long-axis direction is provided. When adopting a ridge knurling structure in which the first angle and the second angle are line symmetric with respect to the long axis direction, the deformable portion 70 with the concave portion 111 as the center bends to the rear side and the front side. The resistance of the first knurling group and the second knurling group becomes the same, and it is possible to suppress bending of the deformable portion 70 in a direction intersecting the thickness direction. Also about the knurling parts 103 and 104, the structure which employ|adopts a ridge knurling structure similarly may be sufficient.

In addition, the cross-sectional shape of the recessed parts 111 and 113 and the convex parts 112 and 114 is not limited to an arc shape, For example, a rectangular shape, a V shape, etc. may be sufficient. When a corner part is included in the cross-sectional shape of the recessed parts 111, 113, since the said corner part may stress concentration, it is preferable that the cross-sectional shape of the recessed part 111, 113 is circular arc shape.

5 is a partial front view of the periphery of the hard portion 70H in the deformable portion 70 . 6 is a partial side view of the periphery of the hard portion 70H in the deformable portion 70 .

As shown in FIG. 5 , the hard part 70H includes a hard part 20H that is the neck part 20 in the long axis direction, and a hard part on the rear end side of the deformable part 70 in the gripping part 30 ( 30H), it is formed in a rectangular shape in a plan view. The width of the hard portion 70H is formed to be smaller than the width of the hard portion 20H and the width of the hard portion 30H.

The hard portion 20H connected to the hard portion 70H constitutes a first region P1 that is more rigid than that of the hard portion 70H in width, thickness, and bending strength in the thickness direction. The hard portion 30H connected to the hard portion 70H constitutes a second region P2 that is more rigid than that of the hard portion 70H in width, thickness, and bending strength in the thickness direction. In each of the first region P1 and the second region P2 in a cross section orthogonal to the major axis direction, the ratio of the hard resin to the soft resin is larger. In the toothbrush 1, when an external force is applied to the back side of the head 10 in a state in which the gripping portion 30 is gripped, the first region P1 on the front end side of the deformable portion 70 and the first region P1 on the rear end side The second region P2 is non-deformable in that the bending strength is greater than that of the hard portion 70H and is rigid, and the deformable portion 70 disposed between the first region P1 and the second region P2 is deformed to the back side.

As shown in FIG. 6, the front-end|tip side of the hard part 70H is connected with the hard part 20H (1st area|region P1) by the curved surface 73H of an arc shape in side view. The rear end side of the front side of the hard part 70H is connected with the hard part 30H (2nd area|region P2) by the curved surface 74H of arc-shaped seen in side view. The arc centers of the curved surfaces 73H and 74H are located on the front side of the hard portion 70H when viewed from the side. The front end of the hard part 70H on the back side is connected to the hard part 20H by a curved surface 75H having an arc shape when viewed from the side. The rear end side of the hard part 70H on the back side is connected to the hard part 30H by the arc-shaped curved surface 76H in side view. The arc centers of the curved surfaces 75H and 76H are located on the back side of the hard portion 70H when viewed from the side. When the curved surfaces 73H to 76H do not exist, stress is concentrated on the boundary between the front end of the hard portion 70H and the hard portion 20H and the rear end of the hard portion 70H and the boundary between the hard portion 30H. There is a possibility. In contrast, the presence of the curved surfaces 73H to 76H relieves the concentrated stress.

As thickness (minimum thickness) of hard part 70H, it is preferable that they are 0.5 mm or more and 2.0 mm or less. When the thickness of the hard part 70H is less than 0.5 mm, the deformation of the deformable part 70 when an external force is applied to the back side of the head part 10 may become large, and the operability at the time of brushing may fall. When the thickness of the hard part 70H exceeds 2.0 mm, it becomes difficult to bend when the external force with respect to the back side is applied to the head part 10. Moreover, when an external force is applied, it becomes difficult to make the hard part 70H into a plane stress state, and durability may fall. Therefore, by making the thickness of the hard part 70H into 0.5 mm or more and 2.0 mm or less, the hard part 70H can be made into the planar stress state, maintaining the operability at the time of brushing.

As a raw material of the hard part H, as an example, the hard resin whose bending elastic modulus (JIS7171) is 1500 MPa or more and 3500 MPa or less is mentioned, For example, polyacetal resin (POM) is mentioned. As a bending elastic modulus of the hard part H, 2000 MPa or more and 3500 MPa or less are more preferable.

As the material of the soft part (E), since the load on teeth etc. falls within an appropriate range even when the brushing load increases, as an example, it is preferable that the shore hardness A is 50 or more and 90 or less, and the shore hardness A is 60 or more and 80 or less. more preferably. When the shore hardness A is less than 50, it may become easy to bend in the width direction. As soft resin, elastomer (For example, an olefin-type elastomer, a styrene-type elastomer, a polyester-type elastomer, a polyurethane-type thermoplastic elastomer, etc.) and silicone are mentioned, for example. A styrenic elastomer is preferable from the viewpoint of being excellent in miscibility with the polyacetal resin.

As a countermeasure against overbrushing in the toothbrush 1, it is effective to ensure a flexible bending behavior and to relieve|moderate a brushing load. Therefore, in the bending behavior of the thickness direction in the toothbrush 1, even when a brushing pressure rises rapidly, it is calculated|required that a load is applied to a tooth etc. by the pressure constant as much as possible. However, if flexibility is provided to the width direction in addition to the thickness direction at the time of brushing, the pressure on the teeth to be originally applied is dispersed, leading to a decrease in cleaning power. In addition, when the head is bent in various directions, it becomes difficult to make the head 10 come into contact with a desired part, which may lead to a decrease in operability.

On the other hand, in the toothbrush 1 of this embodiment, since the said deformable part 70 which has anisotropy in bending strength and is easy to bend in a thickness direction and is hard to bend in a width direction is provided, the fall of the cleaning force mentioned above and operability fall can be suppressed. In addition, as for the deformable part 70 in the toothbrush 1 of this embodiment, compared with the case where the hard part 70H is embedded in the soft part 70E, and the deformable part 70 is formed only with the hard part, Since moderate elasticity acts, the load on the teeth and the like is suppressed even when the brushing pressure rises sharply. In addition, compared to the case where the deformable part 70 is formed only of the soft part, it immediately returns to its original shape when the load is released, and can respond to various movements of the head part 10 .

As described above, in the toothbrush 1 of the present embodiment, the occupancy of the cross-sectional area of the hard portion 70H with respect to the cross-sectional area of the closed space surrounded by the outline or the extension line of the outline is 35% or less over the major axis direction. Since knurling portions 101 and 102 exposed on the front and back sides are provided in the deformable portion 70 in which the bending strength in the thickness direction is easily regulated to be smaller than the bending strength in the width direction, while maintaining an appropriate brushing pressure , it is possible to maintain good operability that the target area can be wiped reliably. Moreover, in the toothbrush 1 of this embodiment, since the knurling parts 103 and 104 exposed on both sides of the width direction of the deformable part 70 are provided, resistance when the deformable part 70 bends in thickness direction. can be reduced, making it easier to bend the deformable portion 70 in the thickness direction.

[Second embodiment]

Then, 2nd Embodiment of the toothbrush 1 is demonstrated with reference to FIGS. 7-12.

In these drawings, the same code|symbol is attached|subjected about the same element as the component of 1st Embodiment shown in FIGS. 1-6, and the description is abbreviate|omitted.

7 : is a front view of the toothbrush 1 which concerns on 2nd Embodiment. 8 : is sectional drawing which cut|disconnected the same toothbrush 1 in the plane containing the center of the width direction (the up-down direction in FIG. 7).

7 and 8, the deformation|transformation part 70 of the toothbrush 1 in this embodiment has the inversion part 80 and the elastic deformation part 90. 9 : is sectional drawing orthogonal to the long-axis direction at the center of the long-axis direction in the deformation|transformation part 70, and is sectional drawing seen along the line B-B in FIG. 10 : is sectional drawing which cut the deformable part 70 in the plane containing the center of the width direction.

The inversion part 80 and the elastically deformable part 90 each have a neck part (first region) 20 on the front end side of the deformable part 70 and a gripping part (second part) on the rear end side of the deformable part 70 . area) 30 are connected. As shown in FIG. 9 , the elastically deformable portions 90 are respectively provided with gaps S on both sides of the inversion portion 80 in the width direction. The gap S is formed of a through hole K penetrating in the thickness direction. As shown in FIG. 7 , the through hole K is formed in a rectangular shape in plan view extending in the major axis direction. That is, the deformable portion 90 branches in the width direction through the through hole K, and each of the branched deformable portions 70 forms the elastically deformable portion 90 .

By providing the gap S, the inversion part 80 can be inverted (it becomes easy to invert) without interfering with the surrounding structure. In addition, since the elastic deformation part 90 and the inversion part 80 do not interfere, the deformation of the inversion part 80 does not follow the deformation of the elastic deformation part, so that the inversion part 80 and the elastic deformation part 90 Functional roles (described later) can be independent.

Thereby, for example, the degree of freedom in design for obtaining the following effects can be increased. For example, it is possible to clearly generate a vibration/sound when the inversion unit 80 to be described later is inverted. In addition, for example, it is possible to increase the repulsive force of the inversion part 80 until the magnitude of the external force reaches the threshold value in proportion to the displacement amount, and in particular, it becomes possible to maintain the proportional relationship even in the vicinity of the threshold value ( The degree of rise of the repulsive force of the inversion part 80 is not gentle). Thereby, since the pressure assumed by the user is reflected in the repulsive force of the inversion part 80 as it is in the area up to the displacement amount reaching the pressure (brushing pressure) used as the upper limit, the brushing load can be appropriately controlled. In the case of a setting in which the degree of rise of the repulsive force gradually becomes gradual in the vicinity of the magnitude of the external force reaching the threshold, the user may unintentionally continue brushing with the pressure near the upper limit. In addition, when the gap S communicates with both sides of the inversion part 80 in the thickness direction, the above effect is further improved.

In addition, by expanding the gap S in the thickness direction, the vector of the load applied to the crushing part (hair) during brushing, the direction in which the gap is opened, and the direction in which the inversion part 80 and the elastically deformable part 90 are deformed. It becomes parallel (refer FIG. 9), and it becomes easy to link generation|occurrence|production of vibration and sound by reversing with a brushing load.

In addition, if the gap S is passed through the front side and the back side with the through hole K, for example, the movable area of the elastically deformable portion 90 responsible for the bending function of the toothbrush skeleton with respect to the load during brushing can be further enlarged. (the tensile behavior at the surface accompanying the warpage, and the compression behavior at the back side are difficult to inhibit). When the through hole K does not exist between the elastically deformable portion 90 and the inverted portion 80 , the movable area of the elastically deformable portion 90 is narrowed. In this case, it is assumed that the trigger for reversing the reversing section 80 is not given in an appropriate load range, and the reversing section 80 reverses before reaching an appropriate load range, or that the reversal does not occur even in an appropriate load range. . On the other hand, by providing the through hole K between the elastically deformable part 90 and the inverting part 80, the threshold value at which the inverting part 80 to be described later reverses can be controlled in a finer range.

In addition, the gap S does not need to penetrate in the thickness direction, and may be formed, for example, by a closed cavity extending in the longitudinal direction inside the elastically deformable portion 90 . Moreover, you may form by the recessed part (described later) opened to the front side or the back side.

Each elastically deformable portion 90 has a hard portion (core portion) 90H and a soft portion (coated portion) 90E. As shown in FIG. 7 , the soft portion 90E connects the rear end of the neck portion 20 and the gripping portion 30 on the rear end side of the deformable portion 70 . 9 and 10, between the pair of elastically deformable portions 90, a depression (recessed portion) 71 opened to the front side and a depression (recessed portion) 72 opened to the rear side. is provided. The bottoms on both ends in the width direction of the recessed portion 71 and the recessed portion 72 are connected to the through hole K, respectively. The inversion part 80 is exposed and provided in the bottom part of the width direction center in the recessed part 71 and the recessed part 72. As shown in FIG. By providing the recesses 71 and 72, for example, the movable area of the elastically deformable part 90 responsible for the bending function of the toothbrush skeleton with respect to the load at the time of brushing is further enlarged, and the bending anisotropy in the thickness direction is improved. can be improved In addition, the said recessed part between a pair of elastic deformation part 90 does not need to penetrate in the thickness direction, and may be opened only in one side of the thickness direction. Further, for example, a closed cavity extending in the longitudinal direction may be formed inside the elastically deformable portion 90 , the cavity may be sandwiched in the center, and a pair of elastically deformed portions 90 may be formed in the width direction. .

As for the pair of elastically deformable parts 90, in both the front side and the back side, the ends of the long-axis direction of the soft part 90E are connected in the width direction. The soft portion 90E of the pair of elastically deformable portions 90 is provided around the oval recesses 71 and 72 when viewed from the front. The rear end side of the soft portion 90E is connected to the soft portion 31E of the gripping portion 30 . When the soft portion 90E is connected in the width direction on both the front end side and the rear end side of the elastically deformable portion 90 , stress is less likely to be concentrated at the end of the hinge structure even if inversion is repeated, and it is difficult to fold. Further, when the soft portion 90E is connected in the width direction on both the front end side and the rear end side of the elastically deformable portion 90 , the anisotropy in the deformable portion 70 increases, and the pair of elastically deformable portions 90 ) can be bent without twisting with respect to the movement during brushing in the thickness direction. In addition, since the amount of heat having the soft resin (elastomer) increases during injection molding by connecting the soft portion 90E in the width direction, the adhesiveness between the neck portion 20 and the deformable portion 70 (neck portion) (20) and the elastically deformable portion (90)) is increased.

As shown in Fig. 9, when the outer contour of the deformable portion 70 does not form a closed space, it includes an extension line of the outline of the front side indicated by the dashed-dotted line and the extension of the outline of the rear side indicated by the dashed-dotted line. The area of the closed space surrounded by the outline is the cross-sectional area of the deformable portion 70 .

11 is a partial front view of the periphery of the hard portion 70H in the deformable portion 70 .

11 , the hard portion 70H has through holes 73 provided on both sides of the inversion portion 80 in the width direction. The through holes 73 each extend in the major axis direction. The length in the major axis direction of the through hole 73 is a length spaced apart from the ends of the hard portions 20H and 30H, respectively. As shown in FIG. 9 , of the through holes 73 , a soft portion 90E is provided near the hard portion 90H in the width direction, and a through hole K is formed near the inverted portion 80 in the width direction in the vicinity of the hard portion 90H. In the hard part 70H, since the hard part 90H is arranged through the through-holes 73 on both sides in the width direction with the inversion part 80 as the center, a load is applied to the elastically deformable part 90. Even if is deformed, the shape of the inversion part 80 can be maintained. When the hard portion H constituting the toothbrush 1 over the entire length is bent, the inverted portion 80 of the deformable portion 70 is inverted in an attempt to release the accumulated deformation energy. For example, when the neck portion 20 and the grip portion 30 are connected to the hard portion 70H only by the inversion portion 80 , the energy cannot be accumulated, and thus the energy is immediately reversed. When the above-described inversion part 80 is integrally injection molded with the first part A1 and the second part A2 described later, and the neck part 20, the grip part 30, and the hard part 70H, the accumulated deformation Energy can be efficiently transferred to the inversion unit 80 .

The hard portion 90H is formed outside the through hole 73 in the width direction among the hard portions 70H. As shown in FIG. 9 , the hard portion 90H has a substantially rectangular cross-sectional shape with a long side extending in the width direction. The hard part 90H is embedded in the soft part 90E in the state covered with it. Since the hard part 90H is embedded in the soft part 90E, the stress applied to the hard part 90H can be relieved from a strength point of view. Moreover, control of the elastic behavior of the elastic deformation part 90 becomes possible in the point of the bending degree of the toothbrush 1 with respect to a load. Moreover, by embedding the hard part 90H in the soft part 90E, the bending anisotropy in the deformable part 70 increases, for example, with respect to the movement at the time of brushing, it elastically deforms without twisting with respect to the thickness direction. It becomes possible to bend the part 90 .

A pair of hard parts 90H is arrange|positioned with respect to the thickness direction at the same position. By arranging the pair of hard portions 90H at the same position in the thickness direction, the anisotropy in the deformable portion 70 increases, and the pair of elastically deformable portions 90 respond to movement during brushing. , it becomes possible to bend without twisting with respect to the thickness direction. Moreover, as a position in the thickness direction of the hard part 90H, it is preferable that it is a back side rather than the position where the thickness of the elastically deformable part 90 becomes half. By being on the back side rather than the position where the thickness of the elastically deformable part 90 becomes half, the easiness of bending with respect to the thickness direction can be ensured, ensuring the behavior of immediately returning to an original shape when a load is released. As a width of the hard part 90H, it is preferable that it is 2.0 mm or more. By making the width|variety of the hard part 90H into 2.0 mm or more, the curvature of the width direction can be suppressed. As a thickness of the hard part 90H, it is preferable that it is 2.0 mm or less. By making the thickness of the hard part 90H into 2.0 mm or less, it becomes easy to bend repeatedly in the thickness direction. The width of the hard portion 90H is preferably larger than the thickness of the hard portion 90H from the viewpoint of making the elastically deformable portion 90 more difficult to bend in the width direction than in the thickness direction.

In addition, the hard portion 90H has the curved surfaces 73H to 76H, so that both the front end side and the rear end side of the elastically deformable portion 90 and the inversion portion 80 can be deformed with flexibility (reversed). The degree of deformation of the elastic deformation portion 90, which is a trigger, can be detected more finely).

The minimum distance between the outer contour of the hard portion 90H and the deformable portion 70 in the width direction, that is, the minimum thickness (thickness) of the soft portion 90E outside the hard portion 90H in the width direction, is preferably 1.0 mm or less. Do. By making the minimum thickness of the said soft part 90E into 1.0 mm or less, the curvature of the width direction can be suppressed.

By using a high modulus material (for example, POM) as the material of the hard part H, even if the shape is thin or thin, when an excessive load is applied, buckling is generated and vibration is expressed. In addition, by using a material having a high modulus of elasticity, it is possible to quickly return to the initial state (the state in which the bending of the elastically deformable portion 90 is released) after the buckling has occurred.

As the material of the soft part (E), it is preferable that, as an example, the shore hardness A is 50 or more and 90 or less, and the shore hardness A is preferably 50 or more and 90 or less from the viewpoint that the load on the teeth etc. enters the appropriate range even if the brushing load increases until the buckling occurs. It is more preferable that A is 60 or more and 80 or less.

The deformable part 70 in the toothbrush 1 of this embodiment has the elastically deformable part 90 in which the hard part 90H was embedded in the soft part 90E, and the elastically deformable part 90 is a hard part. Since moderate elasticity acts compared with the case where it is formed with a bayonet, even when the brushing pressure rises sharply, the load on a tooth etc. is suppressed. In addition, as compared with the case where the elastically deformable portion 90 is formed only of the soft portion, it immediately returns to its original shape when the load is released, and can respond to various movements of the head portion 10 . In addition, in this embodiment, since a pair of elastically deformable parts 90 are arranged side by side in the width direction, bending due to torsion can also be suppressed by suppressing bending in the width direction with respect to a load in the thickness direction, As a result, the fall of the cleaning power mentioned above and the fall of operability can be suppressed.

In addition, in this embodiment, since a pair of elastically deformable parts 90 are arranged side by side in the width direction, bending due to torsion can also be suppressed by suppressing bending in the width direction with respect to a load in the thickness direction, As a result, the fall of the cleaning power mentioned above and the fall of operability can be suppressed.

As shown in FIG. 7 , the inversion portion 80 extends in the longitudinal direction when viewed from the front, and includes a first portion A1 on the distal end side of the through hole 73 in the hard portion 70H and the through hole 73 . ) is a second hard part that connects the second part A2 on the rear end side. The inversion unit 80 is in the first stable state shown in FIG. 10 in which no external force to the back side is applied to the head unit 10 (or an external force equal to or less than a predetermined threshold value to be described later is applied) state), it is formed in a substantially V-shape when viewed from the side that gradually inclines toward the back side from both ends in the long axis direction toward the center. That is, the inversion part 80 is formed in a convex shape on the back side in which the center of a long-axis direction becomes a vertex in a 1st state.

As shown in FIG. 9, a part of the inversion part 80 overlaps with the hard part 90H in the width direction in a 1st state. Moreover, as shown in FIG. 12, a part of the inversion part 80 overlaps with the hard part 90H in the width direction also in the 2nd state mentioned later. Since a part of the inversion part 80 overlaps with the hard part 90H in the width direction in both the first state and the second state, the anisotropy in the deformable part 70 is improved, and a pair of elastically deformable parts (90), it becomes possible to bend without twisting with respect to the movement at the time of brushing with respect to the thickness direction.

In the toothbrush 1 described above, when an external force is applied to the back side of the head 10 in a state in which the gripping portion 30 is gripped, the first region P1 on the front end side of the deformable portion 70 and the rear end side The second region P2 of is non-deformable in that the bending strength is greater than that of the hard portion 70H and is rigid, and the deformable portion 70 disposed between the first region P1 and the second region P2 is deformed to the back side.

At this time, when the magnitude of the external force is less than or equal to a predetermined threshold, the elastically deformable part 90 and the inverted part 80 are elastically deformed according to the magnitude of the external force. In addition, about the knurling part 101 at this time, it bent to the back side, extending in the long-axis direction. With respect to the knurling portion 102, it is bent toward the back side while being compressed in the major axis direction. The knurling portions 101 and 102 are thin in the thickness direction due to the presence of the concave portions 111, and irregularities in the width direction in the front and back (front side and back side) of both branching portions are formed at the same pitch. , it is not twisted in the thickness direction, and can be easily bent to the back side. In addition, in the knurled portions 103 and 104 , since they are thin in the width direction due to the presence of the concave portion 111 , the resistance when the deformable portion 70 is bent in the thickness direction decreases, and the deformable portion 70 ) is more easily bent toward the back side. In addition, by extending and connecting the concavities and convexities (recesses 111 and convex portions 112) of the front and back (front side and rear side) also to the concavities and convexities (concave portions 113 and convex portions 114) of the side portions, in the thickness direction , it can be bent without further twisting.

When the magnitude of the external force exceeds a predetermined threshold, the elastically deformable unit 90 is elastically deformed by bending according to the magnitude of the external force exceeding the threshold. On the other hand, when the magnitude of the external force exceeds a predetermined threshold, the inversion part 80 is reversed by buckling when the neck part 20 is deformed, as shown by the dashed-dotted line in FIG. 12 , and in a second stable state (hereinafter referred to as a second state). In the second state, the inverting portion 80 is inverted in a direction that gradually inclines toward the front side toward the center and becomes substantially inverted V-shape when viewed from the side. In the second state, the inversion portion 80 is formed in a convex shape on the front side in which the center in the long axis direction becomes the apex.

That is, when the magnitude of the external force exceeds a predetermined threshold, the elastic deformation portion 90 is elastically deformed, so that the bending strength in the deformable portion 70 is guaranteed, and the inversion portion 80 is in the first state. The rain buckles and inverts to enter the second state. Moreover, since the through hole K is provided between the inversion part 80 and the elastic deformation part 90, the inversion part 80 and the elastic deformation part 90 become deformable independently of each other, and the inversion part 80 ) is easy to invert. That is, when a brushing load is applied, since the through hole K is provided, the inversion part 80 can be bent after only the elastic member 90 is bent first without inhibiting mutual deformation behavior. In addition, it is not necessary to necessarily penetrate between the inversion part 80 and the elastically deformable part 90, and the gap|interval S should just be formed.

In addition, with respect to the load in the thickness direction on the head portion 10, the elastically deformable portion 90 can suppress bending due to torsion by suppressing bending in the width direction. It can contribute to functioning with high precision with respect to the load. Moreover, with respect to the inversion of the inversion part 80, although it is necessary to accumulate|store deformation energy, as mentioned above, with respect to the load in the thickness direction, since the bending due to torsion is suppressed by suppressing the bending in the width direction, brushing It is possible to efficiently convert the load of time into strain energy. Therefore, in this embodiment, clear repeated buckling of the inversion part 80 is attained at an appropriate timing.

Due to the vibration when the inversion part 80 is inverted by buckling, the user holding the gripping part 30 has an over-brushing state in which the external force applied to the head part 10 on the back side exceeds the threshold value. can detect that

The inversion part 80 has the groove part 81 in the center of the major axis direction in the front side, ie, the area|region including the convex vertex. The inversion part 80 has the groove part 82 in the center of the long-axis direction in the back side, ie, the area|region including the convex vertex. The grooves 81 and 82 extend in the width direction. The groove part 81 is formed in the circular arc shape as seen from the side by which the circular arc center was arrange|positioned on the front side. The groove part 82 is formed in the circular arc shape as seen from the side by which the circular arc center was arrange|positioned on the back side. When the grooves 81 and 82 are not provided in the inversion portion 80 , stress is uniformly generated in the entire inversion portion 80 , making it difficult to generate rain buckling. On the other hand, when the grooves 81 and 82 are formed in the inversion portion 80 , stress is intensively generated in the groove portions 81 and 82 , and thus non-buckling tends to occur.

As a radius of the arc-shaped groove parts 81 and 82 in a side view, it is preferable that they are 1 mm or more and 2 mm or less. When the radius of the groove portions 81 and 82 is less than 1 mm, there is a possibility that the inversion portion 80 does not invert. When the radius of the groove portions 81 and 82 exceeds 2 mm, the vibration at the time of reversal of the inversion portion 80 becomes small and it may become difficult to detect that the over-brushed state is present.

As the depth of the grooves 81 and 82 , it is preferable that the grooves 81 be deeper than the grooves 82 . When the groove part 82 is deeper than the groove part 81, even when the magnitude|size of an external force exceeds a predetermined threshold value, it becomes difficult for the inversion part 80 to reverse. In addition, when the groove part 81 is deeper than the groove part 82, it becomes possible to guide|induce the inversion part 80 so that rain may buckle easily by the front side. In addition, the structure in which the groove part 82 is not provided instead of the structure in which both of the groove parts 81, 82 is provided may be sufficient as the structure in which only the groove part 81 is provided.

In the inversion part 80, since the grooves 81 and 82 are provided in the region including the convex apex, the region including the convex apex is thinner than the other regions. Therefore, the strain energy accumulated by the deformation of the inversion part 80 by the external force exceeding the threshold is released instantly with the groove parts 81 and 82 as a starting point, and the inversion part 80 can be inverted. In addition, as described above, since the deformable portion 70 has high anisotropy and is easy to deform in the thickness direction of the inverted portion 80 , due to the high strain energy caused by the deformation of the inverted portion 80 , the inverted portion 80 is ) can contribute to functions such as efficient inversion in the thickness direction. Moreover, it becomes possible to adjust the position of the groove part 81, 82 of the thickness direction, and to adjust the position where the inversion part 80 reverses from a 1st state to a 2nd state.

In addition, since the grooves 81 and 82 are formed in an arc shape when viewed from the side, for example, compared to the case where they are formed in a V-shape on two intersecting planes, an inverted portion including the grooves 81 and 82 ( 80), the stress concentration at the apex can be relaxed even when the apex moves in the thickness direction.

As a threshold value of the external force with respect to the back side applied to the head part 10, it is an upper limit of an appropriate brushing pressure, for example.

With respect to the plane parallel to the major axis direction and the width direction, as shown in FIG. 10, the angle θ at which the inversion part 80 is inclined is preferably 5 degrees or more and 11 degrees or less, and 7 degrees or more and 11 degrees or less. more preferably. When the inclination angle θ is less than 5 degrees, there is a possibility that the inversion portion 80 is deformed without buckling, thereby making it difficult to detect the over-brushed state. When the inclination angle θ exceeds 11 degrees, it is difficult to reverse the inversion portion 80 due to buckling of the rain due to over-brushing pressure, or when the inversion portion 80 is buckled and inverted, the inversion portion 80 is broken and reversibility is impossible. is likely to disappear.

As a thickness of the inversion part 80, it is preferable that they are 1 mm or more and 2 mm or less except for the groove parts 81 and 82. If the thickness of the inversion portion 80 is less than 1 mm, there is a possibility that it is deformed but does not buckle, and it is difficult to detect that it is in an over-brushed state. When the thickness of the inversion part 80 exceeds 2 mm, the inversion part 80 is buckled by over-brushing pressure, making it difficult to reverse, or the inversion part 80 breaks when the inversion part 80 is buckled and reversed. is likely to disappear.

As a width of the inversion part 80, it is preferable that it is 1.5 mm or more. When the width|variety of the inversion part 80 is less than 1.5 mm, it may become easy to bend in the width direction.

If the maximum thickness of the inversion part 80 is T (mm) and the maximum thickness of the deformable part 70 is t (mm), by defining a value expressed by T / t, an excessive brushing load is applied. When the inversion section 80 is easily inverted, it becomes possible to control the timing (threshold value). As a value expressed by T/t, it is preferable that they are 0.05 or more and 0.35 or less, and it is more preferable that they are 0.10 or more and 0.35 or less. When the value expressed by T/t is less than 0.05, the inversion part 80 is also deformed in a form that follows the bending of the deformable part 70 (elastic deformable part 90), but since the rain does not buckle, over-brushing There is a possibility that it may become difficult to detect that the state is present. When the value expressed in T/t exceeds 0.35, the inversion part 80 is buckled by over-brushing pressure, making it difficult to reverse it, or it breaks when the rain buckles and reverses, so that the reversibility of the inversion part 80 is is likely to disappear.

As shown in Fig. 9, if the maximum width of the inversion portion 80 is L (mm) and the maximum width of the deformable portion 70 is W (mm), by defining a value expressed by L/W, For example, when an excessive brushing load is applied, it becomes possible to control the ease of inversion of the inversion part 80 and the timing (threshold value). It is preferable that they are 0.05 or more and 0.35 or less, and, as for the value expressed by L/W, it is more preferable that they are 0.10 or more and 0.35 or less. When the value expressed by L/W is less than 0.05, the inversion part 80 is also deformed in a form that follows the bending of the deformable part 70 (elastic deformable part 90), but it is difficult to buckle the rain, and the overbrushing state It may be difficult to detect that When the value expressed by L/W exceeds 0.35, the inversion part 80 becomes difficult to deform and invert due to the bending of the handle body 2 occurring in the normal brushing range. Therefore, there is a possibility that the inversion portion 80 becomes difficult to reverse due to buckling by the over-brushing pressure, or breaks when the rain buckles and reverses, and the reversibility of the inversion portion 80 may be lost. That is, by making T/t and L/W within the above range, the flexural strength of the inversion part 80 with respect to the elastically deformable part 90 becomes flexible at a certain ratio, and the elastically deformable part 90 responsible for the handle skeleton With respect to warping, it becomes possible to actuate the inversion portion 80 to show signs of delay. Therefore, even when an excessive brushing load is applied, it becomes possible to control the timing (threshold value) used as a trigger for easy reversal of the inversion part 80 and the inversion part 80 inversion.

As a length of the major axis direction of the inversion part 80, it is preferable that they are 15 mm or more and 30 mm or less, It is more preferable that they are 15 mm or more and 25 mm or less, It is more preferable that they are 15 mm or more and 20 mm or less. The position of the distal end of the inversion portion 80 is the position of the distal end of the through hole 73 . The position of the rear end side of the inversion part 80 is the position of the rear end side of the through hole 73 . When the length in the long axis direction of the inversion part 80 is less than 15 mm, the inversion part 80 buckles and it becomes difficult to invert with normal brushing pressure, and the deformation required for the buckling to occur. there is a possibility that there is no When the length in the major axis direction of the inversion part 80 exceeds 30 mm, the required displacement until the rain buckles is very large, so usability is greatly reduced, and the deformation behavior of the inversion part 80 is elastically deformable part ( 90) is likely to have the same behavior.

The inversion part 80 is located between the external outline of the hair-transplantation|transplantation surface side 11 in the elastic deformation part 90 and the external outline of a back side in side view. More specifically, as a position in the thickness direction of the inversion portion 80, the inversion portion 80 does not protrude from the thickness of the elastically deformable portion 90 when viewed from the side so as not to form the outermost part of the toothbrush. By doing so, for example, it is possible to suppress the inversion unit 80 from contacting the user during use. Specifically, it is preferable that the thickness of the elastically deformable portion 90 is on the back side rather than the position at which it is halved. When the position in the thickness direction of the inversion part 80 is on the back side rather than the position at which it becomes half the thickness of the deformable part 70, when the inversion part 80 is inverted to enter the second state, the inversion part 80 The apex protrudes from the front surface of the elastically deformable portion 90 to reduce the possibility of contact with the user's finger. In addition, since the inversion part 80 is arranged on the back side rather than the position where the thickness of the elastically deformable part 90 becomes half, since the back side is compressed rather than the front side when the inversion part 80 is bent, for example, Energy as a trigger tends to accumulate, and the strain energy can be efficiently transferred to the inversion unit 80 .

It is preferable that they are 1500 MPa or more and 3500 MPa or less, and, as for the bending elastic modulus of the hard resin which comprises the inversion part 80, it is more preferable that they are 2000 MPa or more and 3500 MPa or less. When the flexural modulus of the hard resin is less than 1500 MPa, the inversion portion 80 is deformed but does not buckle, and there is a possibility that it may be difficult to detect an over-brushed state. When the bending elastic modulus of the hard resin exceeds 3500 MPa, it is difficult to reverse the inversion part 80 due to buckling of the rain due to over brushing pressure, or it is broken when the rain is buckled and reversed, so that the reversibility of the inversion part 80 is is likely to disappear. In addition, by using a material having a prescribed flexural modulus, vibration accompanying the buckling of the rain buckling occurs intensively in a short time and becomes sensitive (sharp, large). As a result, the user becomes easy to detect that it is overbrushing.

It is preferable that they are 0.2 mm or more and 5.0 mm or less as a movement distance of the thickness direction of the convex-shaped vertex when the inversion part 80 does buckling. When the moving distance in the thickness direction of an apex is less than 0.2 mm, the vibration at the time of rain buckling becomes small, and it may become difficult to detect that it is an overbrushing state. When the moving distance in the thickness direction of the apex exceeds 5.0 mm, the inversion part 80 becomes difficult to reverse due to buckling due to over-brushing pressure, or breaks when the rain buckles and reverses. There is a possibility that reversibility will be lost. If the moving distance of the reversing part 80 is within the above-described range when the rain buckling, the vibration generated in the rain buckling occurs intensively in a short time and becomes sensitive (sharp, large). As a result, the user becomes easy to detect that it is overbrushing.

As a thickness of the hard part 90H in the elastically deformable part 90, it is 2.0 mm or less, and it is preferable that the width|variety is larger than thickness. When the thickness of the hard part 90H is 2.0 mm or less, since it will be in a plane stress state, it becomes difficult to generate|occur|produce internal stress in the hard part 90H. As a result, it becomes difficult to break even if deformed, and it becomes possible to sufficiently store energy required for inversion of the inversion portion 80 . Moreover, as a result, while being able to clarify the anisotropy of the bending behavior of the elastically deformable part 90, it can make it difficult to twist.

In addition, in the toothbrush 1 of this embodiment, since the inversion part 80 and the elastically deformable part 90 are arrange|positioned with a space|interval in the width direction, the deformable part 70 is further to a front side and a back side. It is easy to deform|transform, and it can be set as the plane stress state which hardly deform|transforms in the longitudinal direction and the width direction. That is, in the toothbrush 1 of this embodiment, the direction in which the inversion part 80 and the elastically deformable part 90 deform|transform is the thickness direction spaced apart from each other in the width direction, It becomes the structure which does not exist on the same plane, there is. In other words, a path in which the elastically deformable portion 90 is deformed by an external force in the thickness direction and a path in which the inversion portion 80 is deformed by an external force in the thickness direction are provided without interference. Therefore, in the toothbrush 1 of this embodiment, since the elastically deformable part 90 and the inversion part 80 are hard to receive a restriction|limiting mutually more, and since it becomes deformable, inversion of the inversion part 80 is required It becomes possible to further fully accumulate energy, and stress is intensively generated in the inversion part 80 (in particular, the groove parts 81 and 82), and sensitive buckling is expressed.

In particular, in the toothbrush 1 of this embodiment, a pair of hard part 90 in the elastically deformable part 90 is arrange|positioned at the same position with respect to the thickness direction, It is an inversion part with respect to hard part 90H. Since a part of (80) overlaps in the width direction in the first state, for example, even when an external force in the width direction is applied to the head portion 10, twisting around the axis extending in the major axis direction is unlikely to occur. Therefore, in the toothbrush 1 of this embodiment, it becomes difficult to deform|transform the deformation|transformation part 70 in the width direction, and can enlarge bending strength.

As shown in FIG. 9 , in a cross section orthogonal to the major axis direction, the cross-sectional area of the space of the recesses 71 and 72 with respect to the maximum cross-sectional area of the deformable portion 70 (a pair from the maximum cross-sectional area of the deformed portion 70 ) The occupancy of the space of the recesses 71 and 72 expressed by the ratio of the cross-sectional area of the elastically deformable portion 90 to the cross-sectional area excluding the cross-sectional area of the inversion portion 80) is preferably 35% or more and 60% or less. Here, the maximum cross-sectional area of the deformable portion 70 is a cross section orthogonal to the long axis direction of the deformable portion 70 shown in FIG. 9 , and virtually connects the outermost outermost portions on the front side of the pair of elastically deformable portions 90 . In addition, it is the area of the figure formed by virtually connecting the outermost sides of the back side of the pair of elastically deformable parts 90 .

When the said occupancy is less than 35 %, the occupancy of the elastically deformable part 90 and the inversion part 80 will become large, and the bending strength with respect to the back side in a thickness direction will become large at the time of brushing. In this case, it is difficult to maintain an appropriate brushing pressure, and it may become difficult to suppress over-brushing. When the said occupancy exceeds 60 %, the occupancy of the elastically deformable part 90 and the inversion part 80 will become small, and the bending strength in the width direction will become small at the time of brushing. In this case, when brushing, the curvature increases with respect to an external force in the width direction, and there is a possibility that it may be difficult to accurately polish the teeth one by one.

[Example]

Hereinafter, although an Example is shown and this invention is demonstrated in detail, this invention is not limited to a following example, The range which does not deviate from the summary can be implemented by changing suitably.

(Examples 1 to 4, Comparative Examples 1 to 4)

Samples of Examples 1 to 4 and Comparative Examples 1 to 4 were produced according to the specifications shown in Table 1 below.

Examples 1-2 and Comparative Examples 1-2 made the toothbrush (corresponding to the toothbrush shown by 1st Embodiment) which does not have the through-hole in a deformation|transformation part, and an inversion part as a sample. Examples 3-4 and the comparative example 3 made the toothbrush (corresponding to the toothbrush shown by 2nd Embodiment) which has the through-hole in a deformation|transformation part, and an inversion part as a sample. In Comparative Example 4, a toothbrush made by Lion Corporation which does not have a deformable part and "Clinica Advantage 3 rows of normal" was used as a sample.

In addition, Examples 1-3 and the comparative example 2 made the toothbrush which provided the knurling in the front side and back side (front and back) of a deformation|transformation part as a sample. About Example 4, in addition to the front side and the back side (front and back) of a deformation|transformation part, the toothbrush which provided the knurling also in the width direction both sides (left and right) was made into the sample.

[Assessment Methods]

For Examples 1 to 4 and Comparative Examples 1 to 4, “feeling that relieves excessive brushing load”, “feeling that can reliably wipe the target site (anisotropy)” and “easiness of buckling of non-ear in the inverted part” were evaluated, respectively. evaluated.

[Test Methods]

A professional panel (5 people) brushes each sample, "the feeling of easing the excessive brushing load by bending (the feeling of being able to hold the appropriate brushing load)", "the feeling of being able to clean the target area reliably" And about each of "easiness of buckling of the ratio of the inversion part when an excessive brushing load is applied", 5 stages were evaluated in actual use, and the average point evaluated. The average value of the ratings was rounded off to two decimal places, and it was set as the number of digits to the first decimal place.

[grade]

5: I feel very much, 4: I feel a little, 3: I do not feel at all, 2: I do not feel very much, 1: I do not feel at all

[Evaluation] ◎+ (Extremely Good): 4.7 to 5.0, ◎ (Very Good): 4.3 to less than 4.7, ○ (Good): 4.0 to less than 4.3, △ (Not Bad): 3.0 to less than 4.0, △- (Not Good): 2.5 to less than 3.0, × (Bad): less than 2.5 points

As shown in [Table 1], in the samples of Examples 1 to 4, in which concavo-convex structure portions (knurled portions) were provided on the front side and the back side of the deformed portion, and the occupancy of the cross-sectional area of the hard portion in the deformed portion was 35% or less, "The feeling that the excessive brushing load is relieved", "the feeling that the target site can be wiped reliably", and in Examples 3 to 4 with the inversion part, good evaluations were all obtained for "the ease of buckling of the nose of the inversion part" lost.

On the other hand, the sample of Comparative Example 2, which has concavo-convex structures on the front side and back side of the deformed portion, but in which the occupancy of the cross-sectional area of the hard portion in the deformed portion exceeds 35%, is “the feeling of relieving excessive brushing load” ' and "the feeling of being able to reliably wipe the target site" was not given a good evaluation either. In addition, although the occupancy of the cross-sectional area of the hard part in the deformed part was 35% or less, even for the sample of Comparative Example 1 in which the concave-convex structure part was not provided on the front side and the back side of the deformable part, "the feeling of relieving the excessive brushing load" and "the feeling of being able to reliably wipe the target site|part", neither a favorable evaluation was obtained. In addition, even for the sample of Comparative Example 4 having no deformable portion or concave-convex structure, good evaluation was not obtained for both "the feeling of relieving the excessive brushing load" and "the feeling of being able to reliably wipe the target site". In addition, with respect to the sample of Example 3, in the sample of Comparative Example 3 in which the deformable portion did not have an uneven structure, good evaluation was not obtained with respect to "the feeling of being able to reliably wipe the target site."

In addition, as shown in [Table 1], the samples of Examples 2 to 4 in which the ratio of the depth of the concave portion to the convex portion in the knurled portion to the maximum thickness of the deformed portion is within the range of 2% or more and 20% or less. In the case of silver, a better evaluation was obtained for "the feeling of being able to reliably wipe the target site" than in Example 1 in which the ratio was out of the range of 2% or more and 20% or less. In addition to the front side and back side of the deformable portion, the sample of Example 4 having concave-convex structure portions also on both sides in the width direction improved the "sensibility of relieving excessive brushing load" compared to the samples of Examples 1 to 3 became

As mentioned above, although preferred embodiment which concerns on this invention was described referring an accompanying drawing, it goes without saying that this invention is not limited to this example. The dosage form, combination, etc. of each structural member shown in the above-mentioned example is an example, In the range which does not deviate from the main point of this invention, it can change variously based on design requirements etc.

For example, in the said embodiment, although the structure in which the knurling part 101-104 is provided in the deformable part 70 was illustrated, it is not limited to this structure, For example, the knurling parts 103, 104 on both sides in the width direction. ) may be provided, and only the knurling portions 101 and 102 may be provided on the front side and the back side.

In addition, in the said embodiment, although the structure in which the deformable part 70 has the elastically deformable part 90 and the inverted part 80 was illustrated, it is not limited to this structure, The elastically deformable part 90 and the inverted part 80 ) may not be provided.

In addition, in the said embodiment, although the structure in which a part of the recessed parts 71 and 72 penetrates through the thickness direction by the through-hole K was exemplified, it is not limited to this structure, Only one of the front side or the back side is opened. configuration may be sufficient.

This invention is applicable to a toothbrush.

1: Toothbrush
2: handle body
10: head
11: Transplanted noodles
20: neck portion (first region)
30: grip portion (second region)
70: deformation part
71, 72: recess (concave)
80: reverse part
81, 82: groove
90: elastic deformation part
90H: hard part (core part)
H: hard part
90E: Covered part
101 to 104: knurling part (concave-convex structure part)
111, 113: concave
112, 114: convex part
P1: first area
P2: second area
E, 31E, 32E: soft part
S: Gap

Claims (10)

It has a head portion provided on the tip side in the major axis direction having a hair-transplantation surface, a gripping portion disposed on a rear end side of the head portion, and a neck portion disposed between the hair-transplantation surface and the grip portion,
The head part and the neck part, at least a part is formed of a hard resin,
a deformable portion disposed in the gripping portion and deformed by an external force in a first direction orthogonal to the hair-transplantation surface;
a first region that is disposed on the tip side of the deformable portion and is non-deformed by an external force in the first direction;
It is disposed on the rear end side of the deformable portion and has a second region that is not deformed by an external force in the first direction,
At least a portion of the holding portion in a cross section orthogonal to the long axis direction from the tip of the holding portion to the second region in the long axis direction is formed of the hard resin,
The deformable part has a hard part formed of the hard resin connecting the first region and the second region, and a soft part formed of a soft resin and covering at least a part of the hard part,
In a cross section orthogonal to the major axis direction, the share of the cross-sectional area of the hard part to the cross-sectional area of the closed space surrounded by the outer contour of the deformable part or an extension line of the outer contour is 35% or less over the major axis direction,
In the deformable portion, the bending strength in the first direction is regulated to be smaller than the bending strength in the long axis direction and in a second direction orthogonal to the first direction,
The soft part has a concave-convex structure part in which a concave part and a convex part extending in a direction crossing the long axis direction are disposed adjacent to each other in the long axis direction,
The said concave-convex structure part is exposed, respectively, and provided on the back side opposite to the said hair-transplantation surface side of a said 1st direction, and the said hair-transplantation surface side of a said 1st direction, The toothbrush characterized by the above-mentioned. The toothbrush according to claim 1, wherein a depth of the concave portion with respect to the convex portion is 2% or more and 20% or less with respect to a maximum thickness of the deformable portion in the first direction. The method according to claim 1 or 2, wherein the deformable portion has a polygonal cross section perpendicular to the major axis direction,
The toothbrush is provided with the concave-convex structure on both sides of the deformable portion in the second direction, respectively. The toothbrush according to claim 3, wherein an outermost portion of the deformable portion in the second direction is located on the back side of the deformable portion in a central position in the first direction. The method according to any one of claims 1 to 4, wherein the deformable part branches in the second direction through a through hole penetrating in the first direction and extending in the long axis direction,
Each of the branched deformable portions includes a core portion in which the hard portion is branched through the through hole to connect the first region and the second region, and the soft portion is branched through the through hole to cover the periphery of the core portion A toothbrush having a covering part to say. The method of claim 5, wherein the hard part has an inverted part that is spaced apart from the core part and penetrates the through hole in the long axis direction to connect the first region and the second region,
The said inversion part, the toothbrush buckling and inverting when the external force of a 1st direction exceeds a threshold value. The method according to any one of claims 1 to 6, wherein the hard part has a flat plate shape,
The length of the said 2nd direction of the said hard part is larger than the length of the said 1st direction of the said hard part, The toothbrush. The toothbrush according to claim 7, wherein the center of the hard portion in the first direction is located on the back side of the deformable portion in the first direction. The toothbrush according to any one of claims 1 to 8, wherein the length in the major axis direction of the deformable portion is 15 mm or more and 30 mm or less. The toothbrush according to any one of claims 1 to 9, wherein the length of the deformable portion in the second direction is 8 mm or more and 20 mm or less.

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