The present invention relates to a toothbrush.
　This application claims priority based on Japanese Patent Application No. 2018-246149 filed in Japan on December 27, 2018, the contents of which are incorporated herein by reference.
Background technology
[0002]
　While the percentage of people at the age of 80 who have 20 teeth is about 50%, the percentage of elderly caries (root caries) is increasing. Root caries is caries of dentin exposed by gingival recession, but since dentin has a higher composition ratio of organic components than enamel, caries progresses faster. One of the causes of the gingival recession is overbrushing, in which brushing is performed with a brushing pressure (brushing pressure) larger than the appropriate value.
[0003]
　As a countermeasure against the above overbrushing, a toothbrush that suppresses excessive brushing pressure by forming the neck part mainly of soft resin has been known, but since the neck part has flexibility in all directions, when brushing It is difficult to stably apply the brush part to the targeted area.
[0004]
　On the other hand, in Patent Document 1, when a load is applied to the tip of the head portion by utilizing a soft resin, it is difficult to deform in the front-back direction of the neck portion (direction orthogonal to the flocked surface), and the side surface direction of the neck portion (flocked). A technique focusing on anisotropy that it is easily deformed in the width direction parallel to the surface) is disclosed. The toothbrush described in Patent Document 1 has a configuration in which an excessive increase in sweep pressure can be efficiently controlled by giving anisotropy flexibility to the neck portion.
Prior art literature
Patent documents
[0005]
Patent Document 1: International Publication No. 2017/0517777
Outline of the invention
Problems to be solved by the invention
[0006]
　However, since the toothbrush described in Patent Document 1 is made of a soft resin and is easily bent, it is intended to maintain an appropriate brushing pressure while polishing while moving the head in various directions. It is difficult to accurately polish the dentition one tooth at a time.
[0007]
　The present invention has been made in consideration of the above points, and an object of the present invention is to provide a toothbrush capable of accurately brushing a tooth row one tooth at a time while maintaining an appropriate brushing pressure.
Means to solve problems
[0008]
　According to the first aspect of the present invention, a head portion provided on the distal end side in the long axis direction and having a hair-planted surface, a grip portion arranged on the rear end side of the head portion, and the bristle-planted surface and the grip portion. It has a neck portion arranged between the two, and the bending strength in the first direction orthogonal to the flocked surface is orthogonal to the long axis direction and the first direction on the rear end side of the flocked surface. It has an anisotropic deformed portion smaller than the bending strength in two directions, and the anisotropic deformed portion connects the second region on the rear end side of the anisotropic deformed portion to the first direction and the said. Each has an elastically deformable portion that can be elastically deformed in the second direction, and the bending load when the head portion is displaced in the first direction with reference displacement amounts of 10 mm, 20 mm, and 30 mm while the grip portion is supported. Each of the above is provided with a toothbrush characterized by being lower than the bending load when the head portion is displaced in the second direction with a reference displacement amount of 10 mm.
[0009]
　Further, in the toothbrush according to one aspect of the present invention, a bending load when the head portion is displaced in the first direction by a reference displacement amount while the grip portion is supported, and the head portion is displaced in the second direction. The difference from the bending load when displaced by the reference displacement amount is characterized in that the reference displacement amount is 5.0 N or more in all of 10 mm, 20 mm, and 30 mm.
[0010]
　Further, in the toothbrush according to one aspect of the present invention, the head portion is moved in the second direction with respect to a bending load when the head portion is displaced in the first direction by a reference displacement amount while the grip portion is supported. The ratio of the bending load when displaced by the reference displacement amount is characterized in that the reference displacement amount is 5.0 or more in all of 10 mm, 20 mm, and 30 mm.
[0011]
　Further, in the toothbrush according to one aspect of the present invention, the bending load when the head portion is displaced in the first direction with a reference displacement amount of 10 mm or 20 mm while the grip portion is supported, and the head portion is described. The difference from the deflection load when displaced in the second direction with a reference displacement amount of 10 mm is characterized by being 4.0 N or more.
[0012]
　Further, in the toothbrush according to one aspect of the present invention, the bending load when the head portion is displaced in the first direction with a reference displacement amount of 10 mm or 20 mm while the grip portion is supported, and the head portion is displaced. The ratio of the bending load when displaced in the second direction with a reference displacement amount of 10 mm is 2.0 or more.
[0013]
　Further, in the toothbrush according to one aspect of the present invention, the deflection load when the head portion is displaced in the second direction by the reference displacement amount is 5. The deflection load when the head portion is displaced in the first direction by the reference displacement amount is 0 N or more, and is characterized in that the reference displacement amount is 3.0 N or less in all of 10 mm, 20 mm, and 30 mm. do.
[0014]
　Further, in the toothbrush according to one aspect of the present invention, the elastically deformed portion is formed of a first hard portion formed of a hard resin and connecting the first region and the second region, and the hard portion formed of a soft resin. It is characterized by having a soft portion that covers the periphery of the.
[0015]
　Further, in the toothbrush according to one aspect of the present invention, the anisotropic deformed portion is open to at least one of the surface on one side and the surface on the other side in the first direction, and the elastically deformed portion and the first. It is characterized by having recesses provided side by side in two directions or a closed cavity extending in the long axis direction inside the elastically deformed portion.
[0016]
　Further, in the toothbrush according to one aspect of the present invention, the elastically deformed portion is characterized in that the elastically deformed portion is provided on both sides of the second direction with the recessed portion interposed therebetween.
[0017]
　Further, in the toothbrush according to one aspect of the present invention, the recess is characterized by including a through hole penetrating the anisotropic deformed portion in the first direction.
[0018]
　Further, in the toothbrush according to one aspect of the present invention, the area of ​​the cavity or the recess is occupied with respect to the maximum area of ​​the anisotropic deformed portion in the cross section orthogonal to the long axis direction of the anisotropic deformed portion. The rate is characterized by being 20% ​​or more and 60% or less.
[0019]
　Further, in the toothbrush according to one aspect of the present invention, the elastically deformed portion is formed of a first hard portion formed of a hard resin and connecting the first region and the second region, and the hard portion formed of a soft resin. It has a soft portion that covers the periphery of the above, is arranged in the cavity or the recess, and has a second hard portion that connects the first region and the second region and is formed of the hard resin, and has the second hard portion. The hard portion is characterized in that at least a part thereof overlaps with the first hard portion in the second direction, and the bending strength in the first direction is smaller than the bending strength in the second direction.
[0020]
　Further, in the toothbrush according to one aspect of the present invention, the second hard portion is arranged with a gap from the elastically deformed portion, and is located on the head portion in the first direction opposite to the flocked surface. It is characterized by jumping and buckling when an external force exceeding the threshold value to the back side is applied.
[0021]
　Further, in the toothbrush according to one aspect of the present invention, the second hard portion has a convex shape toward the back surface side when the external force in the first direction is equal to or less than the threshold value, and the external force in the first direction. Is inverted in a convex shape toward the flocked surface side when the threshold value is exceeded, and the apex of the convex shape is either when the external force is equal to or less than the threshold value or when the threshold value is exceeded. Is also characterized in that it is located in the recess.
[0022]
　Further, in the toothbrush according to one aspect of the present invention, the second hard portion has a groove portion extending in the second direction on at least one of the flocked surface side and the back surface side in the region including the apex of the convex shape. It is characterized by having.
[0023]
　Further, in the toothbrush according to one aspect of the present invention, the length of the anisotropically deformed portion in the major axis direction is 15 mm or more and 30 mm or less.
The invention's effect
[0024]
　INDUSTRIAL APPLICABILITY The present invention can provide a toothbrush capable of accurately brushing a tooth row one tooth at a time while maintaining an appropriate brushing pressure.
A brief description of the drawing
[0025]
FIG. 1 is a view showing an embodiment of the present invention and is a front view of the toothbrush 1.
FIG. 2 is a cross-sectional view of the toothbrush 1 cut along a plane including a center in the width direction.
FIG. 3 is a cross-sectional view of the anisotropic deformed portion 70 cut in a plane parallel to the thickness direction and the width direction.
FIG. 4 is a cross-sectional view of the anisotropic deformed portion 70 cut in a plane parallel to the thickness direction and the long axis direction.
FIG. 5 is a partial front view of the anisotropic deformed portion 70 in the rigid portion 70H.
FIG. 6 is a partial side view of the anisotropic deformed portion 70 in the rigid portion 70H.
FIG. 7 is a cross-sectional view of the anisotropic deformed portion 70 cut along a plane parallel to the thickness direction and the major axis direction to explain that the inverted portion is inverted.
Embodiment for carrying out the invention
[0026]
　Hereinafter, embodiments of the toothbrush of the present invention will be described with reference to FIGS. 1 to 7.
　It should be noted that the following embodiments show one aspect of the present invention, do not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of ​​the present invention. Further, in the following drawings, in order to make each configuration easy to understand, the scale and number of each structure are different from the actual structure.
[0027]
　FIG. 1 is a front view of the toothbrush 1. FIG. 2 is a cross-sectional view of the toothbrush 1 cut along a plane including the center in the width direction (vertical direction in FIG. 1).
[0028]
　The toothbrush 1 of the present embodiment has a head portion 10 arranged on the tip side in the major axis direction (hereinafter, simply referred to as the tip side) and having hair bundles (not shown) implanted, and the length of the head portion 10. The neck portion 20 extended to the rear end side in the axial direction (hereinafter, simply referred to as the rear end side), the anisotropic deformed portion 70 extended to the rear end side of the neck portion 20, and the anisotropic deformed portion. A grip portion 30 (hereinafter, the head portion 10, the neck portion 20, the grip portion 30, and the anisotropic deformed portion 70 are collectively referred to as a handle body 2) extending to the rear end side of the 70 is provided.
[0029]
　The toothbrush 1 of the present embodiment is a molded body in which a hard portion H formed of a hard resin and a soft portion E formed of a soft resin are integrally molded. The hard portion H constitutes at least a part of each of the head portion 10, the neck portion 20, the grip portion 30, and the anisotropic deformed portion 70. The soft portion E constitutes a part of each of the grip portion 30 and the anisotropic deformed portion 70 (details will be described later).
[0030]
[Head portion 10] The
　head portion 10 has a flocked surface 11 on one side in the thickness direction (direction orthogonal to the paper surface in FIG. 1; first direction). Hereinafter, the flocked surface 11 side in the thickness direction will be the front side in the front direction, the side opposite to the flocked surface will be the back side, and the direction orthogonal to the thickness direction and the long axis direction will be the width direction (or as appropriate). , Side direction; second direction). A plurality of flocked holes 12 are formed on the flocked surface 11. Hair follicles (not shown) are planted in the hair-planting holes 12.
[0031]
　The width of the head portion 10, that is, the length in the width direction parallel to the flocked surface 11 on the front side and orthogonal to the long axis direction (hereinafter, simply referred to as width) is not particularly limited, and is, for example, 7 mm or more and 13 mm or less. Is preferable. When it is at least the above lower limit value, a sufficient area for planting hair bundles can be secured, and when it is at least the above upper limit value, operability in the oral cavity can be further enhanced.
[0032]
　The length of the head portion 10 in the major axis direction (hereinafter, simply referred to as a length) is not particularly limited, and is preferably 10 mm or more and 33 mm or less, for example. When the length of the head portion 10 is not less than the above lower limit value, a sufficient area for planting hair bundles can be secured, and when it is not more than the above upper limit value, the operability in the oral cavity can be further enhanced. The boundary between the neck portion 20 and the head portion 10 in the major axis direction in the present embodiment is a position where the width of the neck portion 20 is the minimum value from the neck portion 20 toward the head portion 10.
[0033]
　The length of the head portion 10 in the thickness direction (hereinafter, simply referred to as thickness) can be determined in consideration of the material and the like, and is preferably 2.0 mm or more and 4.0 mm or less. When the thickness of the head portion 10 is at least the above lower limit value, the strength of the head portion 10 can be further increased. When the thickness of the head portion 10 is not more than the above upper limit value, the reachability to the back of the molars can be enhanced and the operability in the oral cavity can be further enhanced.
[0034]
　A hair bundle is a bundle of a plurality of hairs. The length (hair length) from the flocked surface 11 to the tip of the hair bundle can be determined in consideration of the hair waist and the like required for the hair bundle, and is, for example, 6 to 13 mm. All hair bundles may have the same hair length or may be different from each other.
[0035]
　The thickness (hair bundle diameter) of the hair bundle can be determined in consideration of the hair waist and the like required for the hair bundle, and is, for example, 1 to 3 mm. All hair bundles may have the same hair bundle diameter or may be different from each other.
[0036]
　As the hair that constitutes the hair bundle, for example, the diameter of the hair gradually decreases toward the tip of the hair, and the tip of the hair is sharpened (tapered hair). Examples include the same hair (straight hair). Examples of straight hair include those having a flat surface substantially parallel to the flocked surface 11 and those having hemispherically rounded hair tips.
[0037]
　The material of the hair is, for example, polyamide such as 6-12 nylon (6-12NY), 6-10 nylon (6-10NY), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT). ), Polyester such as polyethylene terephthalate (PEN) and polybutylene terephthalate (PBN), polyolefins such as polypropylene (PP), polyolefin-based elastomers, and elastomer resins such as styrene-based elastomers. These resin materials can be used alone or in combination of two or more. Further, as the hair, a polyester hair having a multi-core structure having a core portion and at least one layer or more of a sheath portion provided on the outside of the core portion can be mentioned.
[0038]
　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 shapes of all hairs may be the same or different.
[0039]
　The thickness of the hair can be determined in consideration of the material and the like, and when the cross section is circular, it is, for example, 6 to 9 mil (1 mil = 1/1000 inch = 0.025 mm). Further, in consideration of usability, brushing feeling, cleaning effect, durability and the like, a plurality of hairs having different thicknesses may be used in any combination.
[0040]
[Neck portion 20]
　The length of the neck portion 20 is preferably 40 mm or more and 70 mm or less in terms of operability.
　As an example, the width of the neck portion 20 is formed so as to gradually increase from the position where the minimum value is obtained to the rear end side. The neck portion 20 in the present embodiment is formed so as to gradually increase from the position where the width becomes the minimum value toward the rear end side. Further, the neck portion 20 is formed so that the thickness gradually increases from the position where the thickness becomes the minimum toward the rear end side.
[0041]
　The width and thickness of the neck portion 20 at the minimum position are preferably 3.0 mm or more and 4.5 mm or less. If the width and thickness of the neck portion 20 at the minimum position is at least the above lower limit value, the strength of the neck portion 20 can be further increased, and if it is at least the above upper limit value, the lips can be easily closed and reachable to the back teeth. And the operability in the oral cavity can be further improved. The width and thickness of the neck portion 20 formed so as to gradually increase toward the rear end side from the position where the minimum value is obtained can be appropriately determined in consideration of the material and the like.
[0042]
　The front side of the neck portion 20 in the side view is inclined toward the front side toward the rear end side. The back side of the neck portion 20 in the side view is inclined toward the back side toward the rear end side. The neck portion 20 is inclined in a direction in which the distance from the center in the width direction increases toward the rear end side in the front view.
[0043]
　The boundary between the neck portion 20 and the anisotropically deformed portion 70 in the present embodiment is the position of the tip of the neck side 20 where the elastically deformed portion 90 described later is provided. Here, the width expands from the neck portion 20 toward the grip portion 30 with an arcuate contour in both front view and side view, and the position of the center of curvature of the arc coincides with the changed position in the long axis direction. There is. More specifically, the boundary between the neck portion 20 and the anisotropic deformed portion 70 is in the long axis direction in which the center of curvature changes from the outside of the arcuate contour to the center side in the width direction in the front view shown in FIG. It matches the position. Further, the boundary between the neck portion 20 and the anisotropic deformed portion 70 is the position in the major axis direction in which the center of curvature changes from the outside of the arcuate contour to the center side in the thickness direction in the side view shown in FIG. Match.
[0044]
[Grip portion 30] The
　grip portion 30 is arranged along the long axis direction. As shown in FIG. 1, the length of the grip portion 30 in the width direction gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side, and then extends to a substantially constant length. .. As shown in FIG. 2, the length of the grip portion 30 in the thickness direction gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side, and then extends to a substantially constant length. There is. The position in the major axis direction in which the length of the grip portion 30 in the width direction gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side and then becomes a substantially constant length, and the thickness of the grip portion 30. The positions in the major axis direction are the same so that the length in the radial direction gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side and then becomes a substantially constant length.
　The boundary between the anisotropic deformed portion 70 and the gripped portion 30 in the present embodiment is the position of the tip of the gripped portion side 30 where the elastically deformed portion 90 described later is provided. Here, the width from the anisotropic deformed portion 70 toward the grip portion side 30 is reduced by an arcuate contour in both front view and side view, and the position of the center of curvature of the arc is changed in the long axis direction. Is consistent with. More specifically, the boundary between the anisotropic deformed portion 70 and the gripped portion 30 is in the long axis direction in which the center of curvature changes from the center side in the width direction to the outside of the arcuate contour in the front view shown in FIG. It matches the position. Further, the boundary between the anisotropic deformed portion 70 and the gripped portion 30 is one with the position in the major axis direction in which the center of curvature changes from the center side in the thickness direction to the outside of the arcuate contour in the side view shown in FIG. I am doing it.
[0045]
　The grip portion 30 has a soft portion 31E in the center in the width direction on the front side. The soft portion 31E constitutes a part of the soft portion E. The soft portion 31E gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side in the front view, and then extends at a substantially constant length. In front view, the side edge of the soft portion 31E and the lateral edge of the grip portion 30 in the width direction are formed at a substantially constant distance.
[0046]
　The grip portion 30 has a hard portion 30H. The hard portion 30H constitutes a part of the hard portion H. The hard portion 30H has a recess 31H in which a part of the soft portion 31E is embedded on the front side. The recess 31H gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side in the front view, and then extends at a substantially constant length.
[0047]
　A part of the soft portion 31E protrudes from the hard portion 30H exposed on the front side. The other soft portion 31E is substantially flush with the hard portion 30H exposed on the front side.
[0048]
　The grip portion 30 has a soft portion 32E in the center in the width direction on the back surface side (see FIGS. 1 and 2). The soft portion 32E constitutes a part of the soft portion E. The soft portion 32E has substantially the same outer contour as the outer contour of the soft portion 31E when viewed from the front. That is, the soft portion 32E gradually narrows toward the rear end side from the boundary with the anisotropic deformed portion 70, and then extends at a substantially constant length. In the rear view, the side edge of the soft portion 32E and the lateral edge of the grip portion 30 in the width direction are formed at a substantially constant distance.
[0049]
　The hard portion 30H has a recess 32H (see FIG. 2) in which a part of the soft portion 32E is embedded on the back surface side. The recess 32H gradually narrows from the boundary with the anisotropic deformed portion 70 toward the rear end side in the rear view, and then extends at a substantially constant length.
[0050]
　A part of the soft portion 32E protrudes from the hard portion 30H exposed on the back surface side. The other soft portion 32E is substantially flush with the hard portion 30H exposed on the front side.
[0051]
　Since the soft portion 31E is provided on the front side of the grip portion 30 and the soft portion 32E is provided on the back side, the grip property when gripping the grip portion 30 is improved.
[0052]
[Anisotropy Deformation Unit 70] The
　anisotropic deformation unit 70 has anisotropy in which the deformation characteristics differ depending on the direction in which an external force is applied. Specifically, in the anisotropic deformed portion 70, the bending strength in the thickness direction is smaller than the bending strength in the width direction. That is, the anisotropic deformed portion 70 has a deformation characteristic (bending characteristic) that it is easy to bend in the thickness direction (easy to bend) and hard to bend in the width direction (difficult to bend). Further, the anisotropic deformed portion 70 has a function of sensing that the external force in the first direction orthogonal to the flocked surface 11 exceeds the threshold value (details will be described later).
[0053]
　As shown in FIG. 1, the anisotropic deformed portion 70 is an inverted portion that connects the neck portion 20 on the distal end side of the anisotropic deformed portion 70 and the gripped portion 30 on the rear end side of the anisotropic deformed portion 70. It has 80 and an elastically deformed portion 90.
[0054]
　FIG. 3 is a cross-sectional view of the anisotropic deformed portion 70 cut in a plane parallel to the thickness direction and the width direction. FIG. 4 is a cross-sectional view of the anisotropic deformed portion 70 cut in a plane parallel to the thickness direction and the long axis direction.
　As shown in FIG. 3, the elastically deformed portions 90 are provided with gaps S on both sides of the reversing portion 80 in the width direction. The gap S is formed by a through hole K penetrating in the thickness direction. As shown in FIG. 1, the through hole K is formed in a rectangular shape in a plan view extending in the long axis direction.
　By providing the gap S, the reversing portion 80 can be inverted (easily inverted) without interfering with the surrounding structure. Further, since the elastically deformed portion 90 and the inverted portion 80 do not interfere with each other, the deformation of the inverted portion 80 does not follow the deformation of the elastically deformed portion, so that the functional roles (described later) of the inverted portion 80 and the elastically deformed portion 90 are made independent. be able to. As a result, for example, the degree of freedom in design for obtaining the following effects can be increased. For example, vibration / sound when the reversing unit 80, which will be described later, is reversed can be clearly generated. Further, for example, the repulsive force up to the threshold value can be increased in proportion to the displacement amount, and the proportional relationship can be maintained even in the vicinity of the threshold value (increased repulsive force). The degree does not become loose). As a result, in the region up to the displacement amount reaching the upper limit pressure, the pressure assumed by the user is directly reflected in the repulsive force, so that the brushing load can be appropriately controlled. If the degree of increase in the repulsive force gradually decreases near the threshold value, the user may unintentionally continue brushing at a pressure near the upper limit. Further, if the gap S is communicated with both sides of the reversing portion 80 in the thickness direction, the effect is further improved. By widening the gap S in the thickness direction, the vector of the load applied to the brush portion (brush) during brushing, the direction in which the gap opens, and the direction in which the reversing portion 80 and the elastically deforming portion 90 are deformed become parallel ( (See FIG. 7), it becomes easy to link the generation of vibration / sound due to inversion with the brushing load. Further, if the gap S is penetrated between the front side and the back side by the through hole K, for example, the movable region of the elastic deformation portion 90 which is responsible for the bending function of the toothbrush skeleton with respect to the load at the time of brushing can be further expanded. (The tensile behavior on the front surface and the compression behavior on the back surface due to bending are less likely to be hindered). When the through hole K does not exist between the elastically deformed portion 90 and the inverted portion 80, the movable region of the elastically deformed portion 90 becomes narrow. In this case, the reversing unit 80 is not given an opportunity to reverse in an appropriate load range, and the reversing unit 80 is inverted before reaching an appropriate load range, or the appropriate load range is reached. Even so, it is assumed that the situation will not be reversed. On the other hand, by providing the through hole K between the elastically deformed portion 90 and the reversing portion 80, the “threshold value” at which the reversing portion 80, which will be described later, reverses can be controlled in a finer range. The gap S does not have to penetrate in the thickness direction, and may be formed, for example, by a closed cavity extending in the major axis direction inside the elastically deformed portion 90. Further, it may be formed by a recess (described later) that opens on the front side or the back side.
[0055]
　Each elastically deformed portion 90 has a hard portion 90H and a soft portion 90E. As shown in FIG. 1, the hard portion 90H and the soft portion 90E connect the rear end of the neck portion 20 and the front end of the grip portion 30. As shown in FIGS. 3 and 4, between the pair of elastically deformed portions 90, a recess (recess) 71 that opens on the front side and a recess (recess) 72 that opens on the back side are provided. The bottoms of the recess 71 and the recess 72 on both ends in the width direction are connected to the through hole K, respectively. An inverted portion 80 is exposed and provided at the bottom of the recess 71 and the center in the width direction in the recess 72. By providing the recesses 71 and 72, for example, the movable region of the elastically deformed portion that bears the bending function of the toothbrush skeleton with respect to the load during brushing can be further expanded, and the bending anisotropy in the thickness direction can be improved. The recesses between the pair of elastically deformed portions 90 may not penetrate in the thickness direction, and may be opened in only one of the thickness directions. Further, for example, a closed cavity extending in the long axis direction may be formed inside the elastic deformation portion 90, and the cavity may be sandwiched in the center to form a pair of elastic deformation portions in the width direction. ..
[0056]
　In the pair of elastically deformed portions 90, the ends of the soft portions 90E in the major axis direction are connected to each other in the width direction on both the front side and the back surface side. The soft portions 90E of the pair of elastically deformed portions 90 are 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 grip portion 30. Since the soft portion 90E is connected in the width direction on both the front end side and the rear end side of the elastically deformed portion 90, stress is less likely to be concentrated on the end of the hinge structure even if the inversion is repeated, and the bending is less likely to occur. Further, the anisotropy in the anisotropic deformed portion 70 is increased by connecting the soft portions 90E in the width direction on both the front end side and the rear end side of the elastic deformed portion 90. It is possible to bend without twisting in the thickness direction with respect to the movement of. Further, since the soft portion 90E is connected in the width direction, the amount of heat possessed by the soft resin (elastomer) during injection molding increases, so that the adhesiveness between the neck portion 20 and the anisotropic deformed portion 70 (neck portion 20 and elastic deformed portion 90) is increased. ) Increases.
[0057]
　FIG. 5 is a partial front view of the anisotropic deformed portion 70 around the hard portion 70H. FIG. 6 is a partial side view of the anisotropic deformed portion 70 around the hard portion 70H.
　As shown in FIG. 5, the hard portion 70H is formed in a rectangular shape in a plan view connecting the hard portion 20H which is the head portion 20 and the hard portion 30H of the grip portion 30 in the long axis direction.
[0058]
　As shown in FIG. 6, the front end side of the hard portion 70H is connected to the hard portion 20H by a curved surface 73H having an arc shape in a side view. The rear end side of the front side of the hard portion 70H is connected to the hard portion 30H by a curved surface 74H having an arc shape in a side view. The arc centers of the curved surfaces 73H and 74H are located on the front side of the hard portion 70H in the side view. The tip end side of the hard portion 70H on the back surface side is connected to the hard portion 20H by a curved surface 75H having an arc shape in a side view. The rear end side of the hard portion 70H on the back surface side is connected to the hard portion 30H by a curved surface 76H having an arc shape in a side view. The arc centers of the curved surfaces 75H and 76H are located on the back side of the hard portion 70H in the side view. When the curved surfaces 73H to 76H do not exist, stress may be concentrated on the boundary between the front end side of the hard portion 70H and the hard portion 20H and the boundary between the rear end side of the hard portion 70H and the hard portion 30H. On the other hand, the presence of the curved surfaces 73H to 76H alleviates the concentrated stress. Further, due to the presence of the curved surfaces 73H to 76H, both the elastic deforming portion 90 and the front end side and the rear end side of the reversing portion 80 can be flexibly deformed (the elastic deforming portion 90 that triggers the reversal). The degree of deformation can be sensed in more detail).
[0059]
　The hard portion 70H has through holes 73 provided on both sides of the reversing portion 80 in the width direction. The through holes 73 extend in the major axis direction, respectively. The length of the through hole 73 in the major axis direction is a length that is separated from the ends of the hard portions 20H and 30H, respectively. As shown in FIG. 3, 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 hard portion 70H, since the hard portion 90H is arranged on both sides in the width direction with the reversing portion 80 as the center via the through holes 73, the reversing portion 80 is deformed even if a load is applied and the elastic deforming portion 90 is deformed. Can maintain the shape of. When the hard portion H constituting the toothbrush 1 over the entire length is bent, the inverted portion 80 of the anisotropic deformed portion 70 is inverted in an attempt to release the accumulated strain energy. For example, when the hard portion 70H is connected to the neck portion 20 and the grip portion 30 only by the reversing portion 80, the energy cannot be stored and the portion is immediately inverted. When the reversing portion 80 is integrally injection-molded with the first region A1 and the second region A2, which will be described later, the neck portion 20, the grip portion 30, and the hard portion 70H, the accumulated strain energy is efficiently transferred to the reversing portion. Can be communicated.
[0060]
　The hard portion 90H is formed outside the through hole 73 in the width direction of the hard portion 70H. As shown in FIG. 3, the hard portion 90H has a substantially rectangular cross-sectional shape in which the long side extends in the width direction. The hard portion 90H is embedded in the soft portion 90E in a state where the periphery is covered. Since the hard portion 90H is embedded in the soft portion 90E, the stress applied to the hard portion 90H can be relaxed from the viewpoint of strength. Further, the elastic behavior of the elastically deformed portion 90 can be controlled from the viewpoint of the degree of bending of the toothbrush 1 with respect to the load. Further, the bending anisotropy of the sensing portion 70 is increased, and for example, it is possible to bend the elastic deformation portion 90 without twisting in the thickness direction with respect to the movement during brushing.
[0061]
　The pair of hard portions 90H are arranged at the same position in the thickness direction. By arranging the pair of hard portions 90H at the same position in the thickness direction, the anisotropy in the anisotropic deformed portion 70 is increased, and the pair of elastic deformed portions 90 have a thickness with respect to the movement during brushing. It is possible to bend without twisting in the direction. Further, the position of the hard portion 90H in the thickness direction is preferably on the back surface side of the position where the thickness of the elastically deformed portion 90 is halved. Since the elastically deformed portion 90 is on the back side of the position where the thickness is halved, it is possible to ensure the ease of bending in the thickness direction while ensuring the behavior of immediately returning to the original shape when the load is released. The width of the hard portion 90H is preferably 2.0 mm or more. By setting the width of the hard portion 90H to 2.0 mm or more, bending in the width direction can be suppressed. The thickness of the hard portion 90H is preferably 2.0 mm or less. By setting the thickness of the hard portion 90H to 2.0 mm or less, it becomes easy to repeatedly bend in the thickness direction.
[0062]
　The minimum distance between the hard portion 90H and the widthwise outer contour of the anisotropic deformed portion 70, that is, the minimum thickness (thickness) of the soft portion 90E outside the hard portion 90H in the width direction is 1.0 mm or less. It is preferable to have. By setting the minimum thickness of the soft portion 90E to 1.0 mm or less, bending in the width direction can be suppressed.
[0063]
　Examples of the material of the hard portion H include a hard resin having a flexural modulus (JIS7171) of 1500 MPa or more and 3500 MPa or less, and examples thereof include polyacetal resin (POM). The flexural modulus of the hard portion H is more preferably 2000 MPa or more and 3500 MPa or less. By using a material having a high elastic modulus (for example, POM), even if the shape is made thin or thin, when an excessive load is applied, jumping buckling occurs and vibration is generated. Further, by using a material having a high elastic modulus, it is possible to quickly return to the initial state (a state in which the bending of the elastically deformed portion 90 is released) after buckling occurs.
[0064]
　As a material for the soft portion E, the shore hardness A is 50 or more and 90 or less, as an example, in that the load on the teeth and the like remains within an appropriate range even if the brushing load increases until the jumping buckling occurs. The one having a shore hardness A of 60 or more and 80 or less is more preferable. If the shore hardness A is less than 50, it may easily bend in the width direction. Examples of the soft resin include elastomers (for example, olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, polyurethane-based thermoplastic elastomers, etc.) and silicones. A styrene-based elastomer is preferable because it has excellent miscibility with a polyacetal resin.
[0065]
　歯ブラシ１におけるオーバーブラッシング対策として、柔軟な撓み挙動を担保して、ブラッシング荷重を緩和させることが有効である。そのため、歯ブラシ１における厚み方向の撓み挙動においては、ブラッシング圧が急激に上昇した際にも、なるべく一定の圧力で歯牙等に負荷がかかることが求められる。ただし、ブラッシング時に厚さ方向に加えて幅方向にまで柔軟性を付与すると、本来かけるべき歯牙への圧力が分散してしまい、清掃力の低下に繋がる。また、様々な方向にヘッドが撓む場合、狙った部位にヘッド部１０を当てにくくなり、操作性の低下に繋がる可能性がある。
　これに対して、本実施形態の歯ブラシ１では、曲げ強度に異方性を有し厚さ方向に撓みやすく幅方向に撓みづらい上記の異方性変形部７０が設けられているため、上述した清掃力の低下および操作性の低下を抑制できる。また、本実施形態の歯ブラシ１における異方性変形部７０は、硬質部９０Ｈが軟質部９０Ｅに埋設された弾性変形部９０を有し、弾性変形部９０が硬質部のみで形成されている場合と比較して適度な弾性が作用するため、ブラッシング圧が急激に上昇した際にも、歯牙等への負荷が抑制される。また、弾性変形部９０が軟質部のみで形成されている場合と比較して、負荷を解放したときに直ちに元の形状に戻り、ヘッド部１０の様々の動きにも対応できる。さらに、本実施形態では、一対の弾性変形部９０が幅方向に並んで配置されているため、厚さ方向の負荷に対して、幅方向の撓みが抑えられることで捻れによる撓みも抑制可能であり、その結果、上述した清掃力の低下および操作性の低下を抑制できる。
　As shown in FIG. 5, the reversing portion 80 extends in the long axis direction in the front view, and the first region A1 on the distal end side of the through hole 73 in the hard portion 70H and the second region A1 on the rear end side of the through hole 73. It is a second hard portion connecting the region A2. The reversing portion 80 is in a first stable state (hereinafter, first state) shown in FIG. 4 in which an external force to the back surface side is not applied to the head portion 10 (or an external force equal to or lower than a predetermined threshold value described later is applied). In (referred to as), it is formed in a substantially V shape in a side view that gradually inclines toward the back surface side from both ends in the long axis direction toward the center. That is, in the first state, the reversing portion 80 is formed in a convex shape on the back surface side where the center in the major axis direction is the apex.
[0066]
　As shown in FIG. 3, a part of the reversing portion 80 overlaps with the hard portion 90H in the width direction in the first state. Further, as shown in FIG. 7, a part of the reversing portion 80 overlaps with the hard portion 90H in the width direction even in the second state described later. Since a part of the reversing portion 80 overlaps the hard portion 90H in the width direction in both the first state and the second state, the anisotropy in the anisotropic deformed portion 70 increases, and the pair of elastic deformed portions 90 are brushed. It is possible to bend without twisting in the thickness direction with respect to the movement of time.
[0067]
　For example, when an external force to the back surface side is applied to the head portion 10 while the grip portion 30 is gripped, if the magnitude of the external force is equal to or less than a predetermined threshold value, the elastic deformation portion 90 and the reversing portion 80 have an external force. Elastically deforms according to the size of.
[0068]
　When the magnitude of the external force exceeds a predetermined threshold value, the elastically deformed portion 90 elastically deforms according to the magnitude of the external force exceeding the threshold value. On the other hand, when the magnitude of the external force exceeds a predetermined threshold value, the reversing portion 80 jumps, buckles and reverses when the neck portion 20 is deformed, as shown by the alternate long and short dash line in FIG. 7, and the second It becomes the stable state of 2 (hereinafter referred to as the second state). In the second state, the reversing portion 80 is reversed in a direction in which it gradually inclines toward the front side toward the center and becomes a substantially inverted V-shape in side view. In the second state, the inverting portion 80 is formed in a convex shape on the front side where the center in the major axis direction is the apex.
[0069]
　That is, when the magnitude of the external force exceeds a predetermined threshold value, the elastically deformed portion 90 is elastically deformed, so that the inverted portion 80 is the first in a state where the bending strength in the anisotropic deformed portion 70 is secured. It jumps from the state, buckles and reverses, and becomes the second state. Further, since the through hole K is provided between the reversing portion 80 and the elastically deforming portion 90, the reversing portion 80 and the elastically deforming portion 90 can be deformed independently of each other, and the reversing portion 80 can be easily inverted. Become. That is, since the through hole K is provided when a brushing load is applied, the reversing portion 80 can be flexed after only the elastic member 90 is first flexed without hindering each other's deformation behavior. It should be noted that the space between the reversing portion 80 and the elastically deforming portion 90 does not necessarily have to penetrate, and a gap S may be formed.
　Further, with respect to the load in the thickness direction on the head portion 10, the elastically deformed portion 90 can suppress the bending due to twisting by suppressing the bending in the width direction, so that the reversing portion 80 receives the load in the thickness direction. Can contribute to functioning accurately. Further, for the reversal of the reversing portion 80, it is necessary to store strain energy, but as described above, the bending in the width direction is suppressed with respect to the load in the thickness direction, so that the bending due to twisting is also suppressed. Therefore, the load during brushing can be efficiently converted into strain energy. Therefore, in the present embodiment, the reversing portion 80 can be clearly repeatedly buckled at an appropriate timing.
[0070]
　The user who grips the grip portion 30 due to the vibration when the reversing portion 80 jumps, buckles, and flips, is in an overbrushing state in which the external force applied to the head portion 10 on the back surface side exceeds the threshold value. Can be sensed.
[0071]
　The reversing portion 80 has a groove portion 81 in the center in the long axis direction on the front side, that is, in a region including the apex of the convex shape. The reversing portion 80 has a groove portion 82 in the center in the long axis direction on the back surface side, that is, in a region including the apex of the convex shape. The grooves 81 and 82 extend in the width direction. The groove portion 81 is formed in an arc shape in a side view in which the center of the arc is arranged on the front side. The groove portion 82 is formed in an arc shape in a side view in which the center of the arc is arranged on the back surface side. When the groove portions 81 and 82 are not provided in the reversing portion 80, stress is uniformly generated in the entire reversing portion 80, and jumping buckling is less likely to occur. On the other hand, when the grooves 81 and 82 are provided in the reversing portion 80, stress is intensively generated in the grooves 81 and 82, and jumping buckling is likely to occur.
[0072]
　The radius of the arc-shaped grooves 81 and 82 when viewed from the side is preferably 1 mm or more and 2 mm or less. If the radius of the groove portions 81 and 82 is less than 1 mm, the reversing portion 80 may not be inverted. When the radius of the groove portions 81 and 82 exceeds 2 mm, the vibration of the reversing portion 80 at the time of reversing becomes small, and it may be difficult to detect that the reversing portion 80 is in the overbrushing state.
[0073]
　As for the depth of the groove portions 81 and 82, it is preferable that the groove portion 81 is deeper than the groove portion 82. When the groove portion 82 is deeper than the groove portion 81, the reversing portion 80 is less likely to be inverted even when the magnitude of the external force exceeds a predetermined threshold value. Further, when the groove portion 81 is deeper than the groove portion 82, the reversing portion 80 can be guided so as to be more likely to jump and buckle on the front side. It should be noted that the configuration may be such that both the groove portions 81 and 82 are not provided, but the groove portion 82 is not provided and only the groove portion 81 is provided.
[0074]
　Since the inversion portion 80 is provided with the groove portions 81 and 82 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 reversing portion 80 due to the external force exceeding the threshold value can be instantly released from the groove portions 81 and 82 as the starting point, and the reversing portion 80 can be inverted. Further, as described above, since the anisotropic deformed portion 70 has high anisotropy and is easily deformed in the thickness direction of the inverted portion 80, the strain energy accumulated by the deformation of the inverted portion 80 causes the thickness of the inverted portion 80 to be thick. It can contribute to functions such as efficient inversion in the vertical direction. Further, the positions of the groove portions 81 and 82 in the thickness direction can be adjusted to adjust the position where the reversing portion 80 reverses from the first state to the second state.
[0075]
　Further, since the groove portions 81 and 82 are formed in an arc shape in a side view, for example, as compared with the case where the groove portions 81 and 82 are formed in a V shape on two intersecting planes, the inverted portion 80 including the groove portions 81 and 82 is formed. The stress concentration at the apex can be relaxed even when the apex moves in the thickness direction.
[0076]
　The threshold value of the external force applied to the head portion 10 on the back surface side is, for example, an upper limit value of an appropriate brushing pressure.
[0077]
　As shown in FIG. 4, the angle θ at which the reversing portion 80 is tilted with respect to the plane parallel to the major axis direction and the width direction is preferably 5 degrees or more and 11 degrees or less, and 7 degrees or more and 11 degrees. It is more preferably less than or equal to the degree. When the inclination angle θ is less than 5 degrees, the reversing portion 80 jumps and deforms without buckling, which may make it difficult to detect the overbrushing state. When the inclination angle θ exceeds 11 degrees, the reversing section 80 jumps and buckles due to the overbrushing pressure, making it difficult to flip, or when the flipping section buckles and flips, the flipping section 80 jumps and buckles. It may break and lose its reversibility.
[0078]
　The thickness of the reversing portion 80 is preferably 1 mm or more and 2 mm or less, excluding the groove portions 81 and 82. If the thickness of the reversing portion 80 is less than 1 mm, although it is deformed, it does not jump and buckle, and it may be difficult to detect that it is in an overbrushing state. If the thickness of the reversing portion 80 exceeds 2 mm, the reversing portion 80 jumps and buckles due to the overbrushing pressure, making it difficult to reverse, or the reversing portion 80 breaks when the reversing portion 80 jumps and buckles and reverses. And there is a possibility that the reversibility will be lost.
[0079]
　The width of the reversing portion 80 is preferably 1.5 mm or more. If the width of the reversing portion 80 is less than 1.5 mm, it may easily bend in the width direction.
　Assuming that the maximum thickness of the inverted portion 80 is T (mm) and the maximum thickness of the anisotropic deformed portion 70 is t (mm), an excessive brushing load is specified by specifying a value expressed in T / t. It becomes possible to control the ease of inversion of the inversion unit 80 and its timing (threshold value) when the load is applied. The value represented by T / t is preferably 0.05 or more and 0.35 or less, and more preferably 0.10 or more and 0.35 or less. When the value represented by T / t is less than 0.05, the inverted portion 80 also deforms in a form that follows the bending of the anisotropic deformed portion 70 (elastic deformed portion 90), but does not jump and buckle. , It can be difficult to detect an overbrushing condition. If the value represented by T / t exceeds 0.35, the reversible portion 80 jumps and buckles due to the overbrushing pressure, making it difficult to flip, or jumps and buckles and breaks when flipped. Therefore, there is a possibility that the reversibility of the inversion unit 80 will be lost.
[0080] [0080]
　As shown in FIG. 3, assuming that the maximum width of the inverted portion 80 is L (mm) and the maximum width of the anisotropic deformed portion 70 is W (mm), the value represented by L / W is specified. For example, when an excessive brushing load is applied, it becomes possible to control the ease of reversing of the reversing unit 80 and the timing (threshold value) thereof. The values ​​represented by L / W are preferably 0.05 or more and 0.35 or less, and more preferably 0.10 or more and 0.35 or less. When the value represented by L / W is less than 0.05, the inverted portion 80 also deforms in a form that follows the bending of the anisotropic deformed portion 70 (elastic deformed portion 90), but it does not easily jump and buckle. It can be difficult to detect an overbrushing condition. When the value represented by L / W exceeds 0.35, the inverted portion 80 is less likely to be deformed and inverted due to the bending of the handle body 2 that occurs in the range of normal brushing. Therefore, there is a possibility that the reversing portion 80 jumps and buckles due to the overbrushing pressure, making it difficult to reverse, or when the reversing portion 80 jumps and buckles and reverses, it breaks and the reversibility of the reversing portion 80 is lost. .. That is, by setting T / t and L / W within the above ranges, the bending strength of the reversing portion 80 becomes flexible at a constant ratio with respect to the elastic deforming portion 90, and the bending of the elastic deforming portion 90 that bears the handle skeleton. On the other hand, it becomes possible to operate the reversing unit 80 with a slight delay. Therefore, even when an excessive brushing load is applied, it is possible to control the ease of reversing of the reversing unit 80 and the timing (threshold value) that triggers the reversing of the reversing unit 80.
[0081]
　The length of the reversing portion 80 in the major axis direction is preferably 15 mm or more and 30 mm or less, more preferably 15 mm or more and 25 mm or less, and further preferably 15 mm or more and 20 mm or less. The position of the tip side end portion of the reversing portion 80 is the position of the tip end side end portion of the through hole 73. The position of the rear end side end portion of the reversing portion 80 is the position of the rear end side end portion of the through hole 73. When the length of the reversing part 80 in the major axis direction is less than 15 mm, the reversing part 80 jumps and buckles under normal brushing pressure, making it difficult to reverse, and it is necessary for the jumping buckling to occur. It may not be possible to cause deformation. When the length of the reversing part 80 in the long axis direction exceeds 30 mm, the displacement required for jumping and buckling becomes very large, so that the usability is greatly reduced and the deformation behavior of the reversing part 80 is elastically deformed. There is a possibility that the behavior will be the same as that of the part 90.
[0082]
　The reversing portion 80 is located between the outer contour of the flocked surface side 11 and the outer contour of the back surface side of the elastically deformed portion 90 in the side view. More specifically, the position of the reversing portion 80 in the thickness direction is such that the reversing portion does not protrude from the thickness of the elastically deformed portion 90 in the side view so as not to form the outermost outline of the toothbrush. , It is possible to prevent the reversing part from coming into contact with the user during use. Specifically, it is preferable that the elastically deformed portion 90 is on the back side rather than the position where the thickness is halved. When the position of the inverted portion 80 in the thickness direction is on the back side of the position where the thickness of the anisotropic deformed portion 70 is halved, the inverted portion 80 is inverted and becomes the second state. The possibility that the apex of the 80 protrudes from the front surface of the elastically deformed portion 90 and comes into contact with the user's finger can be reduced. Further, since the reversing portion 80 is arranged on the back surface side from the position where the thickness of the elastically deformed portion 90 is halved, the back surface side is compressed more than the front side when the reversing portion 80 is bent, for example. , The energy that triggers the inversion is likely to be accumulated, and the strain energy can be efficiently transferred to the inversion unit 80.
[0083]
　The flexural modulus of the hard resin constituting the reversing portion 80 is preferably 1500 MPa or more and 3500 MPa or less, and more preferably 2000 MPa or more and 3500 MPa or less. When the flexural modulus of the hard resin is less than 1500 MPa, the reversing portion 80 deforms but does not jump and buckle, and it may be difficult to detect that it is in an overbrushed state. When the flexural modulus of the hard resin exceeds 3500 MPa, the reversible portion 80 jumps and buckles due to the overbrushing pressure, making it difficult to reverse, or when the reversible buckles and reverses, it breaks and reverses. There is a possibility that the reversibility of the part 80 will be lost. Further, by using a material having a specified flexural modulus, vibrations due to jumping and buckling are intensively generated in a short time and become sharp (sharp, large). As a result, the user can easily detect that it is overbrushing.
[0084]
　The moving distance of the convex apex in the thickness direction when the inverted portion 80 jumps and buckles is preferably 0.2 mm or more and 5.0 mm or less. If the moving distance of the apex in the thickness direction is less than 0.2 mm, the vibration at the time of jumping and buckling becomes small, and it may be difficult to detect the overbrushing state. When the moving distance of the apex in the thickness direction exceeds 5.0 mm, the reversible portion 80 jumps and buckles due to the overbrushing pressure, making it difficult to flip, or when the flipping buckles and flips. There is a possibility that it will break and the reversibility of the reversing portion 80 will be lost. If the moving distance of the reversing portion 80 is within the above range when the jumping buckling occurs, the vibration generated by the jumping buckling occurs intensively in a short time and becomes sharp (sharp, large). As a result, the user can easily detect that it is overbrushing.
[0085]
　The thickness of the hard portion 90H in the elastically deformed portion 90 is preferably 2.0 mm or less, and the width is preferably larger than the thickness. When the thickness of the hard portion 90H is 2.0 mm or less, the hard portion 90H is in a plane stress state, so that the hard portion 90H is less likely to generate internal stress. As a result, even if it is deformed, it is less likely to break, and it becomes possible to sufficiently store the energy required for the inversion of the inversion portion 80. Further, as a result, the anisotropy of the bending behavior of the elastically deformed portion 90 can be clarified, and it is possible to make it difficult to twist.
[0086]
　Further, in the toothbrush 1 of the present embodiment, since the reversing portion 80 and the elastic deforming portion 90 are arranged with a gap in the width direction, the anisotropic deforming portion 70 is further deformed on the front side and the back side. It is possible to create a plane stress state that is easy to make and hardly deforms in the long axis direction and the width direction. That is, in the toothbrush 1 of the present embodiment, the direction in which the reversing portion 80 and the elastic deforming portion 90 are deformed is the thickness direction separated from each other in the width direction, and the toothbrush 1 does not exist on the same plane. In other words, the path in which the elastically deformed portion 90 is deformed by the external force in the thickness direction and the path in which the reversing portion 80 is deformed by the external force in the thickness direction are provided in a non-interfering manner. Therefore, in the toothbrush 1 of the present embodiment, the elastic deforming portion 90 and the reversing portion 80 are less likely to be constrained by each other and can be deformed, so that the energy required for reversing the reversing portion 80 can be more sufficiently stored. , Stress is intensively generated in the reversing portion 80 (particularly the groove portions 81 and 82), and sharp jump buckling is developed.
[0087]
　In particular, in the toothbrush 1 of the present embodiment, the pair of hard portions 90 in the elastically deformed portion 90 are arranged at the same position in the thickness direction, and a part of the reversing portion 80 with respect to the hard portion 90H is in the first state. Since they overlap in the width direction, 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 long axis direction is unlikely to occur. Therefore, in the toothbrush 1 of the present embodiment, the anisotropic deformed portion 70 is less likely to be deformed in the width direction, and the bending strength can be increased.
[0088]
　As shown in FIG. 3, in the cross section orthogonal to the long axis direction, the cross-sectional area of ​​the spaces of the recesses 71 and 72 with respect to the maximum cross-sectional area of ​​the anisotropic deformed portion 70 (from the maximum cross-sectional area of ​​the anisotropic deformed portion 70). The space occupancy of the dents 71 and 72 represented by the ratio of the cross-sectional area of ​​the pair of elastically deformed portions 90 and the cross-sectional area of ​​the inverted portion 80 is 20% or more and 60% or less. Is preferable. Here, the maximum cross-sectional area of ​​the anisotropic deformed portion 70 is a virtual cross section of the pair of elastic deformed portions 90 on the front side in a cross section orthogonal to the long axis direction of the anisotropic deformed portion 70 shown in FIG. It is the area of ​​the figure formed by virtually connecting the outermost outer shells on the back surface side of the pair of elastically deformed portions 90.
[0089]
　If the occupancy rate is less than 20%, the occupancy rate of the elastically deformed portion 90 and the reversing portion 80 becomes large, and the bending strength toward the back surface in the thickness direction becomes large during brushing. In this case, it is difficult to maintain an appropriate brushing pressure, and it may be difficult to suppress overbrushing. When the occupancy rate exceeds 60%, the occupancy rate of the elastically deformed portion 90 and the reversing portion 80 becomes small, and the bending strength in the width direction becomes small at the time of brushing. In this case, at the time of brushing, the bending becomes large with respect to the external force in the width direction, and it may be difficult to accurately polish the dentition one tooth at a time.
[0090]
　The length of the anisotropic deformed portion 70 in the major axis direction is preferably 15 mm or more and 30 mm or less, more preferably 15 mm or more and 25 mm or less, and further preferably 15 mm or more and 20 mm or less. ..
[0091]
　If the length of the anisotropic deformed portion 70 in the major axis direction is less than 15 mm, the bending strength toward the back surface side in the thickness direction becomes large during brushing. In this case, it is difficult to maintain an appropriate brushing pressure, and it may be difficult to suppress overbrushing.
If the length of the anisotropic deformed portion 70 in the major axis direction exceeds 30 mm, the bending strength in the width direction becomes small during brushing. In this case, at the time of brushing, the bending becomes large with respect to the external force in the width direction, and it may be difficult to accurately polish the dentition one tooth at a time.
[0092]
　In the above toothbrush 1, the bending load when the head portion 10 is displaced in the thickness direction by the displacement amounts of 10 mm, 20 mm, and 30 mm while the grip portion 30 is supported is the displacement amount of the head portion 10 in the width direction. It is preferably lower than the bending load when the displacement is 10 mm. As a result, sufficient anisotropy is generated in the thickness direction and the width direction with respect to the bending strength, an appropriate brushing pressure that can suppress overbrushing can be easily maintained, and the dentition is accurately polished tooth by tooth. Is possible.
[0093]
　In the above toothbrush 1, the bending load when the head portion 10 is displaced to the back surface side in the thickness direction by the reference displacement amount while the grip portion 30 is supported, and the head portion 10 is displaced by the reference displacement amount in the width direction. The difference from the deflection load at the time of displacement is preferably 5.0 N or more in all of the reference displacement amounts of 10 mm, 20 mm, and 30 mm.
　If the difference in bending load due to the difference in displacement direction (thickness direction or width direction) is less than 5N, the bending strength toward the back side in the thickness direction becomes large during brushing, or with respect to the external force in the width direction during brushing. There is a possibility that the deflection will increase. Further, it is preferable that the deflection load in the side surface direction (width direction) is 5 N or more at any time of displacement in the thickness direction and the width direction. Further, it is preferable that the deflection load in the thickness direction (front direction) is 3N or less at both the displacement in the thickness direction and the displacement in the width direction.
[0094]
　Further, in the above toothbrush 1, the bending load when the head portion 10 is displaced in the thickness direction with a reference displacement amount of 10 mm or 20 mm while the grip portion 30 is supported, and the reference displacement amount of the head portion 10 in the width direction. It is preferable that the difference from the deflection load when the displacement is 10 mm is 4.0 N or more and the deflection load when the displacement is in the width direction is large. As a result, sufficient anisotropy is generated in the thickness direction and the width direction with respect to the bending strength, an appropriate brushing pressure that can suppress overbrushing can be easily maintained, and the dentition is accurately polished tooth by tooth. Is possible.
[0095]
　Similarly, the deflection when the head portion 10 is displaced by the reference displacement amount in the width direction with respect to the deflection load when the head portion 10 is displaced to the back surface side in the thickness direction by the reference displacement amount while the grip portion 30 is supported. The load ratio is preferably 5.0 or more for all of the reference displacement amounts of 10 mm, 20 mm, and 30 mm. If the ratio of the deflection load when displaced to the back surface side by the reference displacement amount to the deflection load when displaced by the reference displacement amount in the width direction is less than 5.0, the bending strength to the back surface side in the thickness direction during brushing is It may become large, or the deflection may become large with respect to an external force in the width direction during brushing. Therefore, by setting the ratio of the flexure load when displaced to the back surface side by the reference displacement amount to the deflection load when displaced by the reference displacement amount in the width direction to 5.0 or more, sufficient anisotropy with respect to bending strength. It is possible to easily maintain an appropriate brushing pressure that can suppress overbrushing, and it is possible to accurately polish the tooth row one tooth at a time.
[0096]
　Further, a deflection load when the head portion 10 is displaced with a reference displacement amount of 10 mm and 20 mm in the thickness direction while the grip portion 30 is supported, and a deflection load when the head portion 10 is displaced with a reference displacement amount of 10 mm in the width direction. It is preferable that the load ratio is 2.0 or more and the deflection load when displaced in the width direction is large. As a result, sufficient anisotropy is generated in the thickness direction and the width direction with respect to the bending strength, an appropriate brushing pressure that can suppress overbrushing can be easily maintained, and the dentition is accurately polished tooth by tooth. Is possible.
[0097]
　As described above, the toothbrush 1 of the present embodiment has an anisotropic deformed portion 70 that exhibits anisotropy in bending strength in the thickness direction and the width direction during brushing, and thus has a gripped portion. The deflection load when the head portion 10 is displaced to the back surface side in the thickness direction with a reference displacement amount of 10 mm, 20 mm, or 30 mm while supporting 30 is displaced by the reference displacement amount of 10 mm in the width direction. It can be made lower than the bending load at the time of making. Therefore, in the toothbrush 1 of the present embodiment, it is possible to easily maintain an appropriate brushing pressure capable of suppressing overbrushing, and it is possible to accurately brush the dentition one tooth at a time.
[0098]
[Examples]
　Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples, and may be appropriately modified and carried out without departing from the gist thereof. can.
[0099]
(Examples 1 to 9, Comparative Examples 1 to 2)
　The deflection load when the head portion is displaced at the reference displacement amounts of 10 mm, 20 mm, and 30 mm in the thickness direction and the width direction, respectively, is the value shown in [Table 1]. Samples of Examples 1 to 9 and Comparative Examples 1 and 2 were produced. The samples of Examples 1 to 9 and Comparative Example 2 were manufactured according to the use shown in [Table 1] regarding the presence or absence of through holes in the thickness direction, the occupancy of the cross-sectional area of ​​the recessed space, and the presence or absence of the inverted portion. bottom. In addition, "Clinica Kid's for 3-5 years old") manufactured by Lion Corporation was used as a sample of Comparative Example 1.
[0100]
(Test method of bending load) For
　each sample, a test in which a load was applied to the flocked surface of the head portion to the back side in the thickness direction and a test in which a load was applied to the head portion in the width direction were performed. For each sample, 3 tests were performed (n = 3). For each test, an autograph tester (AGS-X, manufactured by SHIMADZU) was used as an evaluation device. In the load application test, the grip portion side is chucked from the boundary between the anisotropic deformed portion and the grip portion so that the head portion is horizontal in front view or side view, and each of the head portions in front view and side view. A load was applied vertically downward to the central portion (load cell: 100 N, test speed 20 mm / min), and the deflection load was measured at each position of the displacement amounts of 10 mm, 20 mm, and 30 mm.
[0101]
　The difference between the deflection load A measured by applying a load to the back side in the thickness direction and the deflection load B measured by applying a load in the width direction, and the larger value / deflection of the deflection load A and the deflection load B. The ratio of the smaller value of the load A and the deflection load B was calculated for each position of the displacement amounts of 10 mm, 20 mm, and 30 mm.
[0102]
[Evaluation method]
(1) Maintaining an appropriate brushing load
[Test method] A specialized panel (5 people) brushes using each sample and "relieves the excessive brushing load by bending, and an appropriate brushing load. "Feeling that can be maintained" was evaluated on a 5-point scale in actual use, and the average score was used. The average value of the scores was rounded off to the first decimal place.
[Score] 5 points: Very felt, 4 points: Slightly felt, 3 points: Neither, 2 points: Not very felt, 1 point: Not felt at all
[Evaluation] ◎: 4.6-5 points, ○: 4.1 to 4.5 points, Δ: 3.1 to 4.0 points, ×: 3.0 points or less
[0103]
(2) Careful polishing
[Test method] A specialized panel (5 people) brushed each sample and evaluated the "feeling of being able to polish each tooth carefully" on a 5-point scale in actual use, and evaluated the average score. ..
[Score] 5 points: Very felt, 4 points: Slightly felt, 3 points: Neither, 2 points: Not very felt, 1 point: Not felt at all
[Evaluation] ◎: 4.6-5 points, ○: 4.1 to 4.5 points, Δ: 3.1 to 4.0 points, ×: 3.0 points or less
[0104]
(3) Vibration manifestation of the inverted part
[Test method] A specialized panel (5 people) brushed each sample, and whether or not vibration was felt when the inverted part was inverted was scored on a 5-point scale in actual use. It was evaluated and evaluated as follows by the average value of the scores. The average value of the scores was rounded off to the first decimal place.
[Score] 5 points: Very felt, 4 points: Slightly felt, 3 points: Neither, 2 points: Not very felt, 1 point: Not felt at all
[Evaluation] ◎: 4.6-5 points, ○: 4.1 to 4.5 points, Δ: 3.1 to 4.0 points, ×: 3.0 points or less
[0105]
(4) Reversible inversion of the inversion part
[Test method] A specialized panel (5 people) used each sample for 1 week and evaluated the presence or absence of inversion after 1 week.
[Evaluation] ○: Inverted, ×: No inversion (× if even one is not inverted)
[0106]
　Regarding the evaluation results, ⊚, ○, and Δ were regarded as acceptable (OK), and × was regarded as rejected (NG).
　In the evaluation of the measured load, the recommended value is the load when the user actually brushes with the toothbrush 1 by expressing the vibration at the time of reversal in the range of, for example, 230 to 250 g. It is a value of 200 g.
[0107]
[table 1]

[0108]
　As shown in [Table 1], the deflection load A when the displacement is 10 mm, 20 mm, and 30 mm in the thickness direction is lower than the deflection load B when the displacement is 10 mm in the width direction. In the samples of Examples 1 to 9, the items of "maintaining an appropriate brushing load" and "polishing carefully" are acceptable (OK), and it is possible to easily maintain an appropriate brushing pressure that can suppress overbrushing, and at the same time, It was confirmed that it is possible to accurately brush the dentition tooth by tooth. Further, the difference between the deflection load A and the deflection load B is 5.0 N or more in all of the displacement amounts of 10 mm, 20 mm, and 30 mm, and the deflection load A when the displacement is displaced in the thickness direction at the displacement amounts of 10 mm and 20 mm. For the samples of Examples 1 to 9 in which the difference from the deflection load B when the displacement is 10 mm in the width direction is 4.0 N or more, "maintain an appropriate brushing load" and "carefully polish". It was confirmed that the item "OK" was passed, and it was possible to easily maintain an appropriate brushing pressure capable of suppressing overbrushing and to accurately polish the tooth row one tooth at a time.
[0109]
　Further, an embodiment in which the deflection load A when the displacement is 10 mm, 20 mm, and 30 mm in the thickness direction is lower than the deflection load B when the displacement is 10 mm in the width direction, and the inverted portion is provided. In the samples 1 to 3 and 7 to 9, the items of "displacement of the reversing part" and "reversible reversal of the reversing part" were also passed (OK) with a rating of ○ or higher, and the overbrushing state due to the vibrating part. It is possible to easily recognize that the above is the case, and it is possible to suppress the deterioration of the usability.
[0110]
　Further, the ratio (B / A) of the deflection load A when the displacement is 10 mm and 20 mm in the thickness direction and the deflection load B when the displacement is 10 mm in the width direction is 2.0 or more. In the samples of Examples 1 to 3, 5 to 7, and 9, the items of "maintaining an appropriate brushing load" and "polishing carefully" are acceptable (OK), and appropriate brushing capable of suppressing overbrushing is possible. It was confirmed that the pressure could be easily maintained and that the dentition could be accurately brushed tooth by tooth.
[0111]
　Further, in the samples of Examples 1 to 2 and 9, which have an inversion portion and the ratio of the large value to the small value of the deflection load is 5.0 or more in all of the displacement amounts of 10 mm, 20 mm, and 30 mm, "inversion" is performed. The items of "vibration manifestation of the part" and "reversible reversal of the reversible part" were also passed (OK) with the evaluation of ○ or higher, and it is easy to recognize that the overbrushing state is caused by the vibrating part, and the feeling of use is improved. Deterioration can be suppressed.
[0112]
　On the other hand, Comparative Example 1 in which the deflection load A when the displacement is 10 mm, 20 mm, and 30 mm in the thickness direction is not lower than the deflection load B when the displacement is 10 mm in the width direction. In the sample of, the items of "maintaining proper brushing load" and "polishing carefully" were rejected (NG), maintaining proper brushing pressure that can suppress overbrushing, and dentition one tooth at a time. I was able to confirm that it was not possible to achieve accurate polishing.
[0113]
　Further, the difference between the deflection load A and the deflection load B is 5.0 N or more for all of the displacement amounts of 10 mm, 20 mm, and 30 mm, and the deflection load A and the width when the displacement is displaced in the thickness direction at the displacement amounts of 10 mm and 20 mm. The difference between the deflection load B when displacing with a displacement of 10 mm in the direction is 4.0 N or more, the deflection load A when displacing with a displacement of 10 mm and 20 mm in the thickness direction, and the displacement amount in the width direction. For the sample of Comparative Example 1 which does not satisfy that the ratio (B / A) of the bending load B when displaced at 10 mm is 2.0 or more, "maintain an appropriate brushing load" and "carefully". It was confirmed that the item of "polishing to" was rejected (NG), and it was not possible to maintain an appropriate brushing pressure capable of suppressing overbrushing and to accurately brush the tooth row one tooth at a time.
[0114]
　Further, the difference between the deflection load A and the deflection load B is 5.0 N or more for all of the displacement amounts of 10 mm, 20 mm, and 30 mm, and the deflection load A and the width when the displacement is displaced in the thickness direction at the displacement amounts of 10 mm and 20 mm. The difference between the deflection load B when displacing with a displacement of 10 mm in the direction is 4.0 N or more, the deflection load A when displacing with a displacement of 10 mm and 20 mm in the thickness direction, and the displacement amount in the width direction. For the sample of Comparative Example 2 which does not satisfy that the ratio (B / A) of the bending load B when displaced at 10 mm is 2.0 or more, the item "Maintaining an appropriate brushing load" is displayed. It was rejected (NG), and it was confirmed that it was not possible to maintain an appropriate brushing pressure capable of suppressing overbrushing.
[0115]
　Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above examples. The various shapes and combinations of the constituent members shown in the above-mentioned example are examples, and can be variously changed based on design requirements and the like within a range not deviating from the gist of the present invention.
[0116]
　For example, in the above embodiment, the configuration in which the anisotropically deformed portion 70 is provided between the neck portion 20 and the grip portion 30 is exemplified, but the configuration is not limited to this configuration. The anisotropic deformed portion 70 may have a configuration provided in the neck portion 20 or a configuration provided in the grip portion 30.
[0117]
　Further, in the above embodiment, the configuration in which one inversion portion 80 is provided in the anisotropic deformation portion 70 is exemplified, but the configuration is not limited to this configuration, and a configuration in which a plurality of inversion portions 80 are provided may be used.
　For example, when two reversing portions 80 are provided, one is formed to have a thickness and inclination angle θ that are inverted at the upper limit of the appropriate brushing load, and the other is inverted at the lower limit of the appropriate brushing load. By forming the structure at an angle θ or the like, it is possible to easily specify both the upper limit value and the lower limit value of the brushing load.
[0118]
　Further, in the above embodiment, the configuration in which the anisotropically deformed portion 70 has the elastically deformed portion 90 and the inverted portion 80 is exemplified, but the configuration is not limited to this. The anisotropic deformed portion 70 does not have, for example, an inverted portion, recesses 71 and 72, and a through hole K, and is configured such that the periphery of the hard portion 90H is covered with the soft portion 90E and formed by the elastic deformed portion 90. You may.
[0119]
　Further, in the above embodiment, a configuration in which a part of the recesses 71 and 72 penetrates in the thickness direction through the through hole K is exemplified, but the configuration is not limited to this configuration, and only one of the front side or the back side is opened. May be.
Industrial applicability
[0120]
　The present invention is applicable to toothbrushes.
Code description
[0121]
　1 ... toothbrush, 2 ... handle body, 10 ... head part, 11 ... flocked surface, 20 ... neck part, 30 ... grip part, 70 ... anisotropic deformed part, 71, 72 ... dent (recess), 80 ... inverted part (2nd hard part), 81, 82 ... Groove part, 90 ... Elastically deformed part, 90H ... Hard part (1st hard part), A1 ... 1st region, A2 ... 2nd region, E, 31E, 32E ... Soft part , H ... Hard part, S ... Gap
The scope of the claims
[Claim 1]
　It has a head portion provided on the tip end side in the long axis direction and having a hair-planted surface, a grip portion arranged on the rear end side of the head portion, and a neck portion arranged between the hair-planted surface and the grip portion. and,
　on the rear end side of the flocked surface, the first direction of the bending strength perpendicular to the flocked surface is smaller than the bending strength of the second direction perpendicular to the long axis direction and the first direction anisotropy The
　anisotropic deformed portion has a deformed portion, and the anisotropic deformed portion connects a first region on the distal end side of the anisotropic deformed portion and a second region on the rear end side of the anisotropic deformed portion. It has an elastically deformable portion that can be elastically deformed in the first direction and the second direction, respectively, and the
　head portion is displaced in the first direction with reference displacement amounts of 10 mm, 20 mm, and 30 mm while supporting the grip portion. A toothbrush characterized in that the bending load when the head portion is moved is lower than the bending load when the head portion is displaced in the second direction with a reference displacement amount of 10 mm.
[Claim 2]
　A deflection load when the head portion is displaced by the reference displacement amount in the first direction while the grip portion is supported, and a deflection load when the head portion is displaced in the second direction by the reference displacement amount. The difference is
　the toothbrush according to claim 1 , wherein the reference displacement amount is 5.0 N or more in all of 10 mm, 20 mm, and 30 mm .
[Claim 3]
　The deflection load when the head portion is displaced in the first direction by the reference displacement amount while the grip portion is supported, whereas the deflection load when the head portion is displaced in the second direction by the reference displacement amount.
　The toothbrush according to claim 1 or 2 , wherein the ratio is 5.0 or more in all of the reference displacement amounts of 10 mm, 20 mm, and 30 mm .
[Claim 4]
　When the head portion is displaced in the first direction with a reference displacement amount of 10 mm and 20 mm while the grip portion is supported, and when the head portion is displaced in the second direction with a reference displacement amount of 10 mm. The toothbrush according to any one of claims 1 to 3, wherein the difference from the bending load is 4.0 N or more.
[Claim 5]
　When the head portion is displaced in the first direction with a reference displacement amount of 10 mm and 20 mm while the grip portion is supported, and when the head portion is displaced in the second direction with a reference displacement amount of 10 mm. The toothbrush according to any one of claims 1 to 4, wherein the ratio of the bending load is 2.0 or more.
[Claim 6]
　The deflection load when the head portion is displaced in the second direction by the reference displacement amount is 5.0 N or more in all of the reference displacement amounts of 10 mm, 20 mm, and 30 mm, and the
　head portion is moved in the first direction.
　The toothbrush according to any one of claims 1 to 5 , wherein the bending load when displaced by the reference displacement amount is 3.0 N or less in all of the reference displacement amounts of 10 mm, 20 mm, and 30 mm .
[Claim 7]
　The elastically deforming part has a first rigid portion formed of a hard resin connecting the second region and the first region, and a soft portion which is formed of a soft resin covering the periphery of the rigid portion,
　according to claim 1 The toothbrush according to any one of 6 to 6.
[Claim 8]
　The anisotropically deformed portion is open to at least one of the surface on one side and the surface on the other side in the first direction, and is provided with the elastically deformed portion and the concave portion arranged side by side in the second direction, or the elasticity.
　The toothbrush according to any one of claims 1 to 7 , which has a closed cavity extending in the long axis direction inside the deformed portion .
[Claim 9]

　The toothbrush according to claim 8, 　wherein the elastically deformed portions are provided on both sides of the second direction with the concave portion interposed therebetween .
[Claim 10]

　The toothbrush according to claim 8 or 9, 　wherein the recess includes a through hole that penetrates the anisotropically deformed portion in the first direction .
[Claim 11]
　In the cross section orthogonal to the major axis direction of the anisotropic deformed portion, the occupancy ratio of the cross-sectional area of ​​the space of the cavity or the recess with respect to the maximum cross-sectional area of ​​the anisotropic deformed portion is 20% or more and 60% or less. there,
　toothbrush according to any one of claims 8 10.
[Claim 12]
　The elastic deformation portion has a first rigid portion formed of a hard resin connecting the second region and the first region, and a soft portion which is formed of a soft resin covering the periphery of the rigid portion,
　the cavity Alternatively, it is arranged in a recess and has a second hard portion formed of the hard resin by connecting the first region and the second region, and
　at least a part of the second hard portion is in the second direction.
　The toothbrush according to any one of claims 8 to 11, wherein the toothbrush overlaps with the first hard portion and the bending strength in the first direction is smaller than the bending strength in the second direction .
[Claim 13]
　The second hard portion is arranged with a gap from the elastically deformed portion, and an external force exceeding the threshold value is applied to the head portion to the back surface side opposite to the flocked surface in the first direction.
　The toothbrush according to claim 12 , which jumps and buckles when the toothbrush is used.
[Claim 14]
　The second hard portion has a convex shape toward the back surface when the external force in the first direction is equal to or less than the threshold value, and the flocked surface is formed when the external force in the first direction exceeds the threshold value. 　13. According
　to
claim 13 , the convex shape is inverted to the side, and the apex of the convex shape is located in the concave portion both when the external force is equal to or lower than the threshold value and when the external force exceeds the threshold value . toothbrush.
[Claim 15]

　The toothbrush according to claim 13 　, wherein the second hard portion has a groove extending in the second direction on at least one of the flocked surface side and the back surface side in a region including the apex of the convex shape .
[Claim 16]

　The toothbrush according to any one of claims 1 to 15 　, wherein the length of the anisotropically deformed portion in the major axis direction is 15 mm or more and 30 mm or less .