Toothbrush

Abstract

The utility model provides a toothbrush with high tartar removing capacity. The toothbrush is provided with a handle body and a brush molded body formed from a soft resin. The brush molded body has a head base part and a plurality of filaments extending in the long axis direction from the support surface of the head base part. The filaments are provided with concave parts which are opened on one side of the first direction and are concave on the other side of the first direction. The recessed portion has a first open end located at an end portion on one side in the first direction and on one side in the second direction, a second open end located at an end portion on one side in the first direction and on the other side in the second direction, and a bottom end portion located at a predetermined position in the second direction on the most other side in the first direction. At least a portion of an outer wall on the outermost side in the first direction of a second filament adjacent to the first filament on one side in the first direction among the plurality of filaments is located between a first boundary line passing through the bottom end portion and the first open end and a second boundary line passing through the bottom end portion and the second open end of the first filament.

Description

Technical Field

[0001] The present utility model relates to a toothbrush. Background Art

[0002] An integrally molded toothbrush that uses only an injection molding machine to manufacture a toothbrush has been proposed (for example, Patent Document 1). Since the integrally molded toothbrush integrally molds filaments as cleaning bodies and a head base portion (or head), there is no need for material preparation of the cleaning bodies and a hair implanting machine, and it has the advantage of being able to be manufactured more inexpensively than a hair-implanted toothbrush.

[0003] Since the integrally molded toothbrush manufactures the cleaning bodies by injection molding, from the viewpoint of ensuring moldability, each filament needs to be made thicker compared to a hair-implanted toothbrush. Therefore, in order to ensure the contact feeling, a resin with low hardness is mostly used. In addition, the number of hairs per unit area is limited and the filament density is low, and it has the characteristic that the distance between filaments is farther than that of a hair-implanted toothbrush.

[0004] These characteristics have the problem of causing a decrease in the tartar removal power. In Patent Document 2, a filament having a polygonal cross-sectional shape is disclosed in order to improve the tartar removal power under the constraints of using the above-mentioned low-hardness resin and having a sparse filament density.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Utility Model Laid-Open No. 61-207233

[0008] Patent Document 2: WO 2018 / 044754 Summary of the Utility Model

[0009] Technical Problem to be Solved by the Utility Model

[0010] The filaments molded with a low-hardness resin are soft and easily bend in all directions of front, back, left, and right. Therefore, during the brushing process, the brushing force is difficult to be transmitted to the desired part. In addition, if the filament density is low, a large number of hair tips cannot contact the cleaning object. Moreover, since the distance between filaments is far, it is difficult for the filaments to contact each other during the brushing process, and each filament moves independently, so the state of interaction is extremely small. As a result, the problem of low tartar removal power occurs in the conventional filaments of the integrally molded toothbrush.

[0011] On the other hand, regarding the filaments disclosed in Patent Document 2, under the constraints of the filament density and the number of filaments resulting from the viewpoint of ensuring moldability, by setting the cross-sectional shape to a polygon, the bending of each filament is controlled, and the improvement of the dental calculus removal power is achieved. However, the measures taken for each filament are not sufficient to solve this problem.

[0012] The present utility model is completed in consideration of the above problems, and its purpose is to provide a toothbrush with high tartar removal power.

[0013] Technical solution for solving technical problems

[0014] The present utility model has the following mode.

[0015] [1] A toothbrush, characterized by comprising: a handle body; and a brush molding body formed of a soft resin and disposed on one side in the longitudinal direction of the handle body, the brush molding body having a head base portion and a plurality of filaments extending in the longitudinal axis direction from a support surface on the front side in the thickness direction of the head base, the filaments having a concave portion that opens on one side in a first direction parallel to the support surface and is recessed on the other side in the first direction in a cross-section parallel to the support surface, the concave portion having an end portion on one side in the first direction and a first opening end on one side in a second direction intersecting the first direction, a second opening end on one side in the first direction and on the other side in the second direction, and a bottom end portion at a given position in the second direction and on the farthest side in the first direction, among the plurality of filaments, at least a part of the outer wall on the farthest side in the first direction of the second filament adjacent to the first filament in one side in the first direction is located between a first boundary line and a second boundary line of the first filament, the first boundary line passing through the bottom end portion and the first opening end, and the second boundary line passing through the bottom end portion and the second opening end.

[0016] [2] The toothbrush according to the above [1], wherein the concave portion extends in the longitudinal axis direction and is provided at least on the front end side of the filament.

[0017] [3] The toothbrush according to the above [1] or [2], wherein the cross-sectional shape of the concave portion of the first filament is the same as or similar to the cross-sectional shape of the outer wall on the other side in the first direction of the second filament.

[0018] [4] The toothbrush according to any one of the above [1] to [3], wherein the filament has one such concave portion.

[0019] [5] The toothbrush according to any one of the above [1] to [4], wherein the cross-sectional shape of the filament including the concave portion is V-shaped, U-shaped or C-shaped.

[0020] [6] The toothbrush according to any one of the above [1] to [5], wherein the first direction is the width direction orthogonal to the length direction and the thickness direction or the length direction.

[0021] [7] The toothbrush according to any one of [1] to [6] above, wherein the angle at which the first boundary line intersects the second boundary line is greater than 30° and less than 150°.

[0022] Effect of the utility model

[0023] In the present utility model, a toothbrush with high tartar removal power can be provided. Description of the drawings

[0024] Figure 1 It is a front view of the toothbrush 1 according to the embodiment of the present utility model.

[0025] Figure 2 It is a side view of the brush molded body 20 and the toothbrush 1.

[0026] Figure 3 It is a front view of the handle body 10.

[0027] Figure 4 It is a front view of the fitting protrusion 12 enlarged.

[0028] Figure 5 It is a front view of the brush molded body 20.

[0029] Figure 6 It is a side view of the brush molded body 20.

[0030] Figure 7 It is a sectional view of a plane parallel to the support surface 21a and including the fitting hole 22.

[0031] Figure 8 It is a sectional view of the filament 23 in a plane parallel to the support surface 21a according to the first embodiment.

[0032] Figure 9 It is a sectional view of the filament 23 in a plane parallel to the support surface 21a according to the second embodiment.

[0033] Figure 10 It is a sectional view showing a modification of the second embodiment.

[0034] Figure 11 It is a sectional view of the filament in a plane parallel to the support surface 21a according to the third embodiment.

[0035] Figure 12 It is a sectional view of the filament in a plane parallel to the support surface 21a according to the third embodiment.

[0036] Figure 13 It is a sectional view of the filament in a plane parallel to the support surface 21a according to the third embodiment. Detailed implementation mode

[0037] Hereinafter, with reference to Figures 1 - 13 an embodiment of the toothbrush of the present utility model will be described.

[0038] It should be noted that the following embodiments are used to illustrate one mode of the present utility model without limiting the present utility model, and can be arbitrarily changed within the scope of the technical idea of the present utility model. In addition, in the following drawings, in order to facilitate the understanding of each structure, the scale, quantity, etc. in each structure are different from the actual structure.

[0039] Figure 1 is a front view of the brush molded body 20 and the toothbrush 1 according to this embodiment. Figure 2 is a side view of the brush molded body 20 and the toothbrush 1. The toothbrush 1 includes a rod-shaped handle body 10 and a brush molded body 20. The handle body 10 and the brush molded body 20 are different components. The brush molded body 20 can be detachably mounted (inserted) on the handle body 10. The brush molded body 20 mounted on the handle body 10 is supported by the handle body 10. The brush molded body 20 is formed of a soft resin. The handle body 10 is formed of a hard resin.

[0040] It should be noted that the handle body 10 and the brush molded body 20 may also include other detachable components, or may not be detachable but integrally fixed / molded. As an integrally molded structure, it can be set as a structure in which after the handle body 10 is molded by one-time molding, the brush molded body 20 is embedded and molded in a CAP manner by secondary molding, or it can be set as a structure in which the brush molded body 20 that penetrates the head in the thickness direction is embedded and molded.

[0041] It should be noted that the front in this embodiment refers to the side where the filaments 23 described later protrude in the normal direction of the support surface 21a (described in detail later) of the brush molded body 20, that is, the thickness direction (hereinafter simply referred to as the thickness direction) ( Figure 2 the upper side in). In the thickness direction of the brush molded body 20, the side opposite to the front side is appropriately referred to as the back side. In addition, the length direction of the handle body 10 (hereinafter simply referred to as the length direction), the direction in which the brush molded body 20 is inserted into the handle body 10 (hereinafter simply referred to as the insertion direction) is orthogonal to the above normal direction. In the length direction, the side where the handle body 10 is mounted with respect to the brush molded body 20 is referred to as the rear end side, and the side opposite to the rear end side is appropriately referred to as the front end side. In addition, the direction orthogonal to the above normal direction and the insertion direction is the width direction of the brush molded body 20 (hereinafter, simply referred to as the width direction). The major axis direction in this embodiment refers to the direction in which the filaments 23 extend, and is a direction parallel to the above normal direction.

[0042] Figure 3 is a front view of the handle body 10.

[0043] AsFigure 3 As shown, the handle body 10 includes a rod-shaped handle portion 11 and a fitting protrusion 12 provided at the front end of the handle portion 11 and protruding toward the front end side in the length direction of the handle portion 11. In the toothbrush 1, by inserting the fitting protrusion 12 of the handle body 10 into a brush molding body 20 described later, the brush molding body 20 is covered and installed on the fitting protrusion 12.

[0044] The handle body 10 is formed of a hard resin. As an example of the hard resin, a resin having a flexural modulus (JIS K7171) of 1500 MPa or more and 3000 MPa or less can be exemplified. Specifically, for example, polybutylene terephthalate resin (PBT), polypropylene resin (PP), polyoxymethylene resin (POM), polyester resin (PCTA), polyethylene terephthalate copolymer (PETG), and high-density polyethylene (HDPE) can be exemplified. Among these, if the manufacturing cost is considered, polypropylene resin, which is a general-purpose resin, is preferred, and if the strength is considered, polybutylene terephthalate resin and polyoxymethylene resin are preferred.

[0045] In the present embodiment, the front view shape of the handle portion 11 changes curvilinearly in such a manner that the width gradually narrows from the front end side toward the rear end side, then extends with a certain width, and then the width gradually widens and then narrows. The rear end portion of the front view shape of the handle portion 11 has a substantially semicircular shape.

[0046] As Figure 2 shown, the side view shape of the handle portion 11 extends with a certain width from the front end side toward the rear end side, and then the width gradually widens to the maximum thickness of the finger contact portion. The side view shape of the handle portion 11 changes curvilinearly in such a manner that the width gradually narrows from the finger contact portion with the maximum thickness toward the rear end side. The rear end portion of the side view shape of the handle portion 11 has a substantially semicircular shape.

[0047] It should be noted that in the present utility model, the shape of the handle portion 11 is not limited to the shape of this example, and can be appropriately set in consideration of strength, operability, designability, etc.

[0048] The size of the handle portion 11 is not particularly limited and can be appropriately set. For example, the length of the handle portion 11 can be set to 100 mm to 200 mm.

[0049] The fitting protrusion 12 is a portion covered by the brush molding body 20 when the brush molding body 20 is installed on the handle body 10. The rear end of the fitting protrusion 12 is the rear end position of the brush molding body 20 when the brush molding body 20 is installed on the handle body 10.

[0050] Figure 4 is a front view of the fitting protrusion 12 enlarged. As Figure 4As shown, the fitting protrusion 12 has a base portion 13 provided on the front end side of the handle portion 11 and a front end portion 14 provided on the front end of the base portion 13. Although not shown in the figure, the base portion 13 and the front end portion 14 have steps on both the front side and the back side with respect to the handle portion 11, and are formed to have the same thickness that is thinner than the handle portion 11.

[0051] Figure 5 is the front view of the brush molded body 20. Figure 6 is the side view of the brush molded body 20. As Figure 5 and Figure 6 shown, the brush molded body 20 includes a head base portion 21 having a substantially rectangular shape in the front view and a plurality of filaments 23 provided on the front surface of the head base portion 21.

[0052] As the soft resin constituting the brush molded body 20, various elastomers can be used, but polyurethane is preferably used.

[0053] Polyurethane tends to have a higher tensile strength compared to other elastomers such as styrene-based and polyester-based elastomers. Therefore, by using polyurethane in the soft resin, mechanical strength can be ensured even for thin walls, and breakage during the fitting of the handle body 10 into the fitting hole 22 and during the use of the toothbrush 1 can be suppressed.

[0054] In polyurethane, 0.01 wt% to 1.0 wt% (mass%) of any one or a combination of saturated / unsaturated hydrocarbons having 10 or more carbon atoms, higher alcohols, fatty acid amides, fatty acid esters, low molecular weight polyethylene, polyethylene glycol (PEG), fatty acid metal salts, long-chain fatty acids, fatty acid glycerols, liquid paraffin, and silicone is blended to function as a lubricant and a mold release agent.

[0055] In addition, compared to the above-mentioned other elastomers, polyurethane has a wider range of selectable hardnesses. According to the thickness of the brush molded body 20, the resin hardness can be selected considering its usability (for example, the bending of the front end of the brush molded body). As the hardness of polyurethane, a Shore hardness of 90A or more and 100A or less is preferred, or a Shore hardness of 40D or more and 70D or less is preferred.

[0056] When the hardness of polyurethane is less than Shore 90A, it is likely to deform easily when formed with a thin wall, so the fitting becomes weak and the brush molded body 20 is likely to fall off during the use of the toothbrush 1. When the hardness of polyurethane is greater than Shore 70D, when the back surface of the head base portion 21 is inclined, pain may be caused when the front end touches the oral tissue. By setting the hardness of polyurethane to 90A or more and 70D or less, it is possible to suppress the brush molded body 20 from falling off during the use of the toothbrush 1 or pain from being caused when the front end of the head base portion 21 abuts.

[0057] In addition, as polyurethane, from the viewpoint of ensuring water resistance and antibacterial properties, ether-based polyurethane is preferably used.

[0058] The head base portion 21 has a fitting hole 22. The fitting hole 22 extends in the insertion direction and opens at the end face 21b on the rear end side (one side). Figure 7 It is a sectional view of a plane parallel to the support surface 21a including the fitting hole 22. As Figure 7 shown, the fitting hole 22 has a first portion 33 that opens at the end face 21b and a second portion 34 located more inward than the first portion 33. As Figure 6 shown, the first portion 33 and the second portion 34 are respectively arranged separately from the support surface 21a and the back surface 21c of the head base portion 21c.

[0059] The head base portion 21 has a protrusion 35 at approximately the center in the insertion direction of the fitting hole 22, which is located between the first portion 33 and the second portion 34. The protrusions 35 are provided on both sides in the width direction of the fitting hole 22. The protrusions 35 are respectively provided at positions where the fitting protrusions 12 of the handle body 10 are fitted with the depressions 15 when inserted into the fitting hole 22. The protrusions 35 are in an arc shape that has an arc center on the outside in the width direction and protrudes inward.

[0060] When the fitting protrusion 12 of the handle body 10 is inserted into the fitting hole 22 of the head base portion 21, the base portion 13 is fitted with the first portion 33, the front end portion 14 is fitted with the second portion 34, and the protrusion 35 is fitted with the depression 15. Thus, the handle body 10 and the head base portion 21 are integrated.

[0061] [First Embodiment of the Filament 23]

[0062] The filament 23 is substantially columnar, protruding from the support surface 21a on the front side in the thickness direction of the head base portion 21 and extending in the long axis direction. A plurality of filaments 23 are arranged in a lattice pattern when viewed from the front. The support surface 21a of the head base portion 21 is a plane parallel to the width direction and the insertion direction. The support surface 21a is arranged at the base end position of the filament 23 in the thickness direction.

[0063] As Figure 8 shown, the filament 23 is formed in a V shape in a cross section parallel to the support surface 21a. Hereinafter, unless otherwise specified, the cross-sectional shape of the filament 23 will be described.

[0064] In Figure 8 , as the plurality of filaments 23, a first filament 23A and a second filament 23B are shown. The second filament 23B is arranged separately at the rear end side in the length direction corresponding to one side of the first direction with the same orientation with respect to the first filament 23A. In the present embodiment, the positions of the first filament 23A and the second filament 23B in the width direction are the same.

[0065] The filament 23 has an outer wall that forms a side 25 extending in the width direction within a triangle and is located on the rear end side. The filament 23 has a recess 24 that opens in the outer wall which is one side of the triangle. The recess 24 extends in the long axis direction. The recess 24 is a triangle that opens on the rear end side on the side 25 of the filament 23. By providing the triangular recess 24 on the outer wall of the triangle, the filament 23 forms a V shape that opens on the rear end side.

[0066] Since the filament 23 has the recess 24, the second moment of area of the cross-section of the filament 23 becomes inconsistent along the direction of the support surface 21a, anisotropy occurs in the flexure mode of the filament 23, and it is prone to flex in a specific direction. As a result, the force during brushing is easily transmitted to the desired part (Effect 1).

[0067] In addition, since the second filament 23B is arranged with the same orientation on the side where the recess 24 of the first filament 23A opens, during brushing, the unevenness of the adjacent first filament 23A and second filament 23B is likely to overlap, and the distance between the first filament 23A and the second filament 23B becomes closer. Therefore, even if the filaments 23 are arranged at the same density / number as in the prior art that can ensure formability, the dynamic tip density during brushing can be relatively increased compared to the prior art (Effect 2).

[0068] Furthermore, during brushing, the unevenness of the adjacent first filament 23A and second filament 23B is likely to overlap, thereby inducing the overlapping part to act as a thicker filament 23. Generally, the thicker the structure, the higher the rigidity, and thus the resistance during the flexure of the filament 23 can be increased (Effect 3).

[0069] In addition, the unevenness of the adjacent first filament 23A and second filament 23B is likely to overlap, so during brushing, the contact and non-contact between the first filament 23A and the second filament 23B are repeated. Therefore, in addition to the conventional "scrubbing", stains in the oral cavity can also be removed by "pinching" (Effect 4).

[0070] In order to achieve the above effects, it is preferable that three or more filaments 23 are arranged continuously. By arranging three or more filaments 23 continuously, at least one filament 23 has both concave and convex functions, and the above effects can be effectively demonstrated.

[0071] In the recess 24, one side in the width direction corresponding to the second direction that intersects the first direction and is the end on the rear end side is defined as the first opening end 26A, the other side in the width direction that is the end on the rear end side is defined as the second opening end 26B, and the vertex of the triangle that is the frontmost end side corresponding to the outermost side in the first direction and is a given position in the width direction is defined as the bottom end portion 26C. A first boundary line 27A passing through the bottom end portion 26C and the first opening end 26A is set, and a second boundary line 27B passing through the bottom end portion 26C and the second opening end 26B is set.

[0072] As the second filament 23B disposed on the side where the recess 24 of the first filament 23A opens, at least a part of the outer wall on the frontmost end side is located between the first boundary line 27A and the second boundary line 27B. In Figure 8 this case, the vertex 28 of the outer wall of the second filament 23B is located between the first boundary line 27A and the second boundary line 27B.

[0073] Thus, when the second filament 23B flexes, it is inserted into the recess 24 of the first filament 23A and is likely to overlap, and the above effects can be easily obtained.

[0074] The recess 24 extends in the long axis direction among the plurality of filaments 23 and is provided at least on the front end side. The "front end side" means that when the pile length of the filament 23 is defined as 100%, it is defined as 60% of the front end side. The flexure of the base end side of the filament 23 during brushing is small, and the possibility of adjacent filaments 23 contacting is also low. Therefore, even if the recess 24 is not provided, there is no hindrance.

[0075] If the range where the recess 24 is provided is less than 60%, a state where there is no recess in the area where the filament 23 contacts the teeth and gums is generated, which is not preferable.

[0076] As the range where the recess 24 is provided in the filament 23, it is more preferably 60% or more of the front end side, and further preferably 80% or more.

[0077] The cross-sectional shape of the recess 24 of the first filament 23A is preferably the same as or similar to the cross-sectional shape of the outer wall 25B on the front end side of the second filament 23B.

[0078] Thus, when the adjacent first filament 23A and second filament 23B overlap, the contact area between the inner wall 24A and the outer wall 25B of the recess 24 increases, and the above effects 2 to 4 can be more easily exerted.

[0079] In the filament 23, the distance L2 between the line segment connecting the first opening end 26A and the second opening end 26B and the bottom end portion 26C, which is the depth of the recess 24, is preferably 0.1 mm or more. Further, the distance L2 is preferably 2 times or more the distance L1 between the bottom end portion 26C and the vertex 28 of the outer wall, which is the thickness of the filament 23 in the depth direction of the recess 24. As the cross-sectional area of the recess 24, it is preferably 0.0013 cm 2 or more, and more preferably 0.0050 cm 2 or more.

[0080] Further, the cross-sectional area of the recess 24 is preferably 1% or more, more preferably 10% or more, and still more preferably 20% or more of the imaginary cross-sectional area of the filament 23 including the recess 24.

[0081] When the depth L2, the cross-sectional area, and the cross-sectional area ratio of the recess 24 are below the lower limit, the difference in the ease of flexure in the direction of the presence or absence of the recess 24 becomes small, and it is difficult to exhibit the above-described effect 1.

[0082] Further, the contact state between the front end sides of adjacent filaments 23 is also unstable, and it is difficult to exhibit the above-described effects 2 to 4.

[0083] Further, the cross-sectional area of the recess 24 is preferably 85% or less, more preferably 65% or less, and still more preferably 45% or less of the imaginary cross-sectional area of the filament 23 including the recess 24.

[0084] When the cross-sectional area ratio of the recess 24 exceeds the upper limit, even if the front end sides of adjacent filaments 23 overlap each other, the resistance during flexure is insufficient, and it is difficult to exhibit the above-described effect 3.

[0085] In the filament 23, the outer wall shape and the inner wall of the recess 24 are preferably in a similar relationship. In adjacent filaments 23, the inner wall 24A of the recess 24 and the outer wall 25B are the same, and in one filament 23, the outer wall and the inner wall of the recess 24 are in a similar relationship. Therefore, when adjacent filaments 23 come into contact with each other, the contact area becomes larger, and it is easier to exhibit the above-described effects 2 to 4.

[0086] The apex angle of the vertex 28 of the first filament 23A is preferably equal to or greater than the apex angle of the vertex 28 of the second filament 23B. When the apex angle of the vertex 28 of the second filament 23B is greater than the apex angle of the vertex 28 of the first filament 23A, the tip of the second filament 23B is difficult to be received in the recess 24 of the first filament 23A, and stable contact cannot be achieved. Therefore, it is difficult to exhibit the above-described effects 2 to 4.

[0087] The direction in which the recess 24 of the filament 23 opens is not limited to the length direction, and may also be the width direction.

[0088] The distance between the bottom end portion 26C of the first filament 23A and the apex 28 of the second filament 23B is preferably 1.5 mm or less, and smaller is more preferable.

[0089] If the above distance exceeds the upper limit, it is difficult for the first filament 23A and the second filament 23B to come into contact during brushing, and it is difficult to exhibit the above effects 2 to 4.

[0090] More preferably, the apex 28 of the second filament 23B is closer to the bottom end portion 26C of the first filament 23A than the line segment connecting the first opening end 26A and the second opening end 26B of the first filament 23A.

[0091] As the number of the concave portions 24 of the filament 23, one is preferable.

[0092] There is one concave portion of the filament 23, whereby the flexural anisotropy of the filament 23 becomes more distinct, and the above effects are further enhanced.

[0093] As the crossing angle θ between the first boundary line 27A and the second boundary line 27B, it is preferably greater than 30° and less than 150°, and more preferably greater than 45° and less than 120°.

[0094] If the crossing angle θ is 30° or less, the filament 23 is likely to flex in the direction orthogonal to the opening direction, and it is difficult to overlap with the adjacent filament 23 in the opening direction, and it is difficult to exhibit the above effects 2 to 4. In addition, if the crossing angle θ is 150° or more, the resistance during the flexure of each filament 23 is weak, and even in the state of overlapping with the adjacent filament 23, the resistance during the flexure still becomes insufficient, and it is difficult to exhibit the above effect 3.

[0095] It should be noted that as the filament 23, symmetry is preferable, but it is not necessarily symmetric.

[0096] As described above, in the toothbrush 1 of the present embodiment, since the concave portion 24 is provided in the filament 23, the filament 23 is likely to flex in a specific direction, and a part of the outer wall 25B on the front end side of the second filament 23B adjacent to the first filament 23A on the rear end side among the plurality of filaments 23 is located between the first boundary line 27A and the second boundary line 27B. Therefore, the concavities and convexities are likely to overlap when the first filament 23A and the second filament 23B flex. Therefore, in the toothbrush 1 of the present embodiment, the plaque removal power can be improved.

[0097] [Second Embodiment of Filament 23]

[0098] Next, with reference to Figure 9 a second embodiment of the filament 23 will be described.

[0099] In this figure, for Figures 1 - 8Elements having the same structure as those of the first embodiment shown are denoted by the same reference numerals, and their description is omitted.

[0100] In the above first embodiment, an example is shown in which the filaments 23 adjacent in the longitudinal direction are arranged in a lattice structure at the same position in the width direction. In the second embodiment, as Figure 9 shown, the filaments 23 adjacent in the longitudinal direction are arranged in a staggered pattern at different positions in the width direction.

[0101] More specifically, the recess 24 of the second filament 23B adjacent to the first filament 23A on the rear end side is provided with the same orientation as the recess 24 of the first filament 23A, and the position in the width direction is arranged to be different from the position in the width direction of the first filament 23A. The vertices 28 of the second filament 23B are respectively located between the first boundary line 27A and the second boundary line 27B of the first filament 23A.

[0102] In this embodiment, since the vertices 28 of the second filament 23B are respectively located between the first boundary line 27A and the second boundary line 27B of the first filament 23A, when the first filament 23A and the second filament 23B are bent, the concavities and convexities are also likely to overlap.

[0103] Therefore, in this embodiment, the same functions and effects as those of the above first embodiment can be obtained.

[0104] It should be noted that, in addition to the lattice arrangement and the staggered arrangement, as a modification example of the second embodiment, as Figure 10 shown, the orientations in which the recesses 24 open may also be different. Figure 10 The second filament 23B shown also includes the recess 24 and the outer wall 25B, and is arranged in a direction of rotation around an axis extending in the thickness direction with respect to the first filament 23A.

[0105] As described above, the vertices 28 of the second filament 23B arranged in a direction of rotation with respect to the first filament 23A are respectively located between the first boundary line 27A and the second boundary line 27B of the first filament 23A. Thus, when the first filament 23A and the second filament 23B are bent, the concavities and convexities are likely to overlap.

[0106] Therefore, by applying this modification example, for example, the present utility model can be applied to a case where the filaments 23 are arranged radially along the support surface 21a.

[0107] [Third Embodiment of the Filament 23]

[0108] Next, refer to Figures 11 - 13 to describe the third embodiment of the filament 23.

[0109] In these figures, for Figures 1 - 8Elements having the same structure as those of the first embodiment shown are denoted by the same reference numerals, and their description is omitted.

[0110] In the above embodiment, a structure in which the recess 24 has a triangular shape and the outer wall 25B also has a triangular shape is illustrated. In the third embodiment, a structure in which at least one of the recess 24 and the outer wall 25B is different from the triangular shape will be described.

[0111] As Figure 11 shown, the recess 24 of the filament 23C has a triangular shape, and the outer wall 29 has a rectangular shape. When the filaments 23C are adjacent in the direction in which the recess 24 opens, one of the filaments 23C may be arranged such that a part of the side of the outer wall 29 facing the recess 24 is located between the first boundary line and the second boundary line described above.

[0112] The recess 24 of the filament 23D has a triangular shape, and the outer wall 29 has a circular shape.

[0113] The recess 24 of the filament 23E has a triangular shape, and the outer wall 29 has an X-shaped. The filament 23E has four recesses 24 with different opening directions.

[0114] Regarding the filaments 23D and 23E, when filaments 23D and 23E having the same shape are adjacent in the direction in which the recess 24 opens, one of the filaments 23D and 23E may be arranged such that at least a part of the outer wall 29 of one of the adjacent filaments 23D and 23E is located between the first boundary line and the second boundary line defined by the recess 24 of the other of the adjacent filaments 23D and 23E.

[0115] As Figure 12 shown, the recess 24 of the filament 23F has a trapezoidal shape, and the outer wall 29 has a triangular shape. The central position of the side of the bottom end portion 26C of the trapezoidal recess 24 that is farthest from the opening side is defined as a given position.

[0116] The filament 23G is formed in a U shape in which the recess 24 has a trapezoidal shape and the outer wall 29 has a trapezoidal shape.

[0117] The filament 23H is formed in a C shape in which the recess 24 has a trapezoidal shape and the outer wall 29 has a rectangular shape.

[0118] Regarding the filaments 23F, 23G, and 23H, when filaments 23F, 23G, and 23H having the same shape are adjacent in the direction in which the recess 24 opens, one of the filaments 23F, 23G, and 23H may be arranged such that at least a part of the outer wall 29 of one of the adjacent filaments 23F, 23G, and 23H is located between the first boundary line and the second boundary line defined by the recess 24 of the other of the adjacent filaments 23F, 23G, and 23H.

[0119] AsFigure 13 As shown, the concave portion 24 of the filament 23J has a semi-circular shape, and the outer wall 29 has a semi-circular shape.

[0120] Regarding the filament 23J, when filaments 23J of the same shape are adjacent in the direction in which the concave portion 24 opens, it is sufficient to arrange one of the filaments 23J such that at least a part of the outer wall 29 of one of the adjacent filaments 23J is located between the first boundary line and the second boundary line defined by the concave portion 24 of the other of the adjacent filaments 23J.

[0121] The combination of the concave portion 24 and the outer wall 29 in the above-mentioned filaments 23D to 23J is an example. When filaments 23 of the same shape are adjacent in the direction in which the concave portion 24 opens, various shapes can be selected as long as at least a part of the outer wall 29 of one of the adjacent filaments 23 is located between the first boundary line and the second boundary line defined by the concave portion 24 of the other of the adjacent filaments 23.

[0122] In addition, it is not necessary for filaments 23 of the same shape to be adjacent, and a structure in which a plurality of filaments 23 having different shapes of at least one of the concave portion 24 and the outer wall 29 are arranged adjacent to each other may also be used.

[0123] As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but it goes without saying that the present invention is not limited to the above examples. The shapes, combinations, etc. of the respective structural components shown in the above examples are examples, and various changes can be made according to design requirements and the like without departing from the gist of the present invention.

[0124] For example, in the above embodiment, a structure in which the filament 23 is straight hair is illustrated, but the present invention is not limited to this structure, and it may also be tapered hair with a tapered tip.

[0125] If the filament 23 has a tapered shape, the problem that the filament 23 formed of a soft resin is easily bent in all directions becomes more obvious. However, by providing the concave portion 24, the above effects 1 to 4 are produced. In particular, by producing effect 1 (anisotropy in the bending mode) and effect 3 (increase in the resistance during bending due to overlap), the "softness" of the tapered hair can be suppressed and the advantages in the case of using tapered hair such as gap intrusion can be enjoyed.

[0126] [Symbol Explanation]

[0127] 1…Toothbrush, 10…Handle body, 12…Fitting projection, 20…Brush molded body, 21…Head base portion, 21a…Support surface, 22…Fitting hole, 23, 23C, 23D, 23E, 23F, 23G, 23H, 23J…Filaments, 23A…First filament, 23B…Second filament, 24…Recess, 26A…First open end, 26B…Second open end, 26C…Bottom end portion, 27A…First boundary line, 27B…Second boundary line.

Claims

1. A toothbrush, characterized in that: have: a handle body; and The brush molding is formed of soft resin and is arranged on one side in the length direction of the handle body. The brush forming body comprises: Head base portion; as well as a plurality of filaments extending in the longitudinal direction from a support surface located on the front side in the thickness direction of the head base portion, The filament has a concave portion that is open on one side of a first direction parallel to the support surface and is recessed on the other side of the first direction in a cross section parallel to the support surface. The recess has: a first opening end located at an end portion of one side of the first direction and located at one side of a second direction intersecting the first direction; a second opening end located at an end portion on one side of the first direction and located at the other side of the second direction; as well as a bottom end portion, which is located at the othermost side in the first direction and at a given position in the second direction, Among the multiple filaments, at least a portion of the outer wall of a second filament adjacent to the first filament on one side of the first direction and located on the other side of the first direction is located between a first boundary line and a second boundary line of the first filament, the first boundary line passes through the bottom end portion and the first opening end, and the second boundary line passes through the bottom end portion and the second opening end.

2. The toothbrush according to claim 1, characterized in that The recessed portion extends along the longitudinal direction and is provided at least on the front end side of the filament.

3. The toothbrush according to claim 1 or 2, characterized in that: The cross-sectional shape of the concave portion of the first filament is the same as or similar to the cross-sectional shape of the outer wall of the second filament located on the other side of the first direction.

4. The toothbrush according to claim 1 or 2, characterized in that: The filament has one recess.

5. The toothbrush according to claim 1 or 2, characterized in that: The cross-sectional shape of the filament including the recessed portion is V-shaped, U-shaped, or U-shaped.

6. The toothbrush according to claim 1 or 2, characterized in that: The first direction is a width direction or the length direction that is orthogonal to the length direction and the thickness direction.

7. The toothbrush according to claim 1 or 2, characterized in that: An angle at which the first boundary line intersects the second boundary line is greater than 30° and less than 150°.

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