Toothbrush and method of manufacturing a toothbrush

Abstract

The toothbrush has a brush portion having a plurality of brush members and a toothbrush body in which the brush portion is integrally formed on the front surface of the head portion, the brush member formed of a soft resin having a hardness of 70 or less has a base portion, a plurality of filaments formed on the surface of the base portion, and a first fitting portion formed on the back surface of the base portion and fitted to the toothbrush body, and the toothbrush body formed of a hard resin has a second fitting portion fitted to the first fitting portion.

Description

Technical Field

[0001] This invention relates to toothbrushes and methods for manufacturing toothbrushes.

[0002] This application claims priority based on Japanese Patent Application No. 2020-214890, filed on December 24, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] Users have vastly different oral conditions, and their preferences for toothbrush design also vary. However, when trying to provide a wide variety of toothbrushes to suit every user, productivity decreases and the price of toothbrushes increases.

[0004] When a brush head is constructed by embedding a tuft of bristles formed from multiple bristles in the head, many types and materials of bristles are required to manufacture various types of brush heads. Therefore, a toothbrush that can replace various brush heads relative to the toothbrush body (head) has been proposed (e.g., Patent Document 1). Furthermore, in the case of a structure in which a brush head made of soft resin is integrally formed relative to a toothbrush body (head) made of hard resin, various shapes or thicknesses of filaments can be achieved using a single soft resin, depending on the type of mold used during injection molding.

[0005] [Existing technical documents]

[0006] [Patent Literature]

[0007] Patent Document 1: JP 2004-154269 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] However, in such a one-piece toothbrush structure, when attempting to achieve the same level of multi-variety production as the brush head formed by bristles, it is necessary to prepare a large number of molds for forming the brush head, based on the size, arrangement pattern, etc. of the head in the toothbrush body.

[0010] The present invention was made in view of the above circumstances, and its object is to provide a toothbrush and a method for manufacturing a toothbrush that can control manufacturing costs and cope with the production of multiple varieties in an integrally formed structure of a head made of hard resin and a brush part made of soft resin.

[0011] [Methods used to solve problems]

[0012] One aspect of the toothbrush of the present invention comprises a brush portion having a plurality of brush pieces and a toothbrush body having the brush portion integrally formed on the front side of the head. The brush pieces, formed of a soft resin with a D hardness of 70 or less, have a base portion, a plurality of filaments formed on the surface of the base portion, and a first fitting portion formed on the back side of the base portion and fitting into the toothbrush body. The toothbrush body, formed of a hard resin, has a second fitting portion fitting into the first fitting portion.

[0013] In one embodiment of the toothbrush of the present invention, the structure may be configured such that the first fitting portion is formed on the back side of the base portion opposite to the surface on which the plurality of filaments are formed, and the ratio of the length of the first fitting portion from the back side to the length of the filaments from the surface is 0.2 or more and 1.0 or less.

[0014] In one embodiment of the toothbrush of the present invention, multiple brush members of any one or more different types of the soft resin hardness, the filament length, the filament shape, the filament color, and the type of soft resin are arranged together.

[0015] In one embodiment of the toothbrush of the present invention, the structure may be configured such that the first fitting portion is cylindrical.

[0016] In one embodiment of the toothbrush of the present invention, the toothbrush component may be configured such that, in the injection-molded brush member, the first fitting portion has a draft angle cone on its outer periphery, the draft angle cone having a draft angle θ relative to a direction perpendicular to the back surface being less than 3°.

[0017] In one embodiment of the toothbrush of the present invention, the toothbrush may be configured as follows: the brush portion has the plurality of brush members and a retaining portion for holding each of the plurality of brush members, the plurality of brush members being inserted into the plurality of first fitting portions from the front side of the retaining portion in a plurality of through holes in the thickness direction of the retaining portion, and being interconnected to each other on the back side of the retaining portion, the retaining portion being disposed in a front side recess of the front opening of the head.

[0018] In one embodiment of the toothbrush of the present invention, the toothbrush may be configured such that: the toothbrush has a filling portion connecting each of the first fitting portions of the plurality of brush members, the toothbrush body has a rear side recess with an opening on the rear side of the head, and the filling portion is formed in the rear side recess.

[0019] In the toothbrush manufacturing method of the present invention, there are steps including: forming a brush part having a plurality of brush members formed of a soft resin with a D hardness of 70 or less, and integrally forming the brush part and the toothbrush body. In the step of manufacturing the brush part, the brush member having a base portion, a plurality of filaments formed on the surface of the base portion, and a first fitting portion formed on the back side of the base portion and fitting with the toothbrush body is formed. In the step of integrally forming the brush part and the toothbrush body, the toothbrush body having a second fitting portion fitting with the first fitting portion is formed.

[0020] [The effects of the invention]

[0021] According to the present invention, a toothbrush and a method of manufacturing a toothbrush can be provided, wherein, in an integrally formed structure of a head and a brush portion, in an integrally formed structure of a head made of hard resin and a brush portion made of soft resin, manufacturing costs can be controlled and multi-variety production can be handled. Attached Figure Description

[0022] [ Figure 1 ] Figure 1 This is a perspective view showing the overall structure of a toothbrush according to an embodiment of the present invention.

[0023] [ Figure 2 ] Figure 2 It is an exploded perspective view of the head and brush head of a toothbrush.

[0024] [ Figure 3 ] Figure 3 It is a perspective view showing a magnified portion of the main part of the brush.

[0025] [ Figure 4 ] Figure 4 It is along Figure 1 The cross-sectional view of line IV-IV is shown.

[0026] [ Figure 5 ] Figure 5 This is a perspective view showing an example of the configuration of filaments in a brush component.

[0027] [ Figure 6 ] Figure 6 This is a perspective view showing an example of the shape of the first fitting part in the brush component.

[0028] [ Figure 7 ] Figure 7 This is a diagram illustrating the method of manufacturing a toothbrush in the embodiment.

[0029] [ Figure 8A ] Figure 8A This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0030] [ Figure 8B ] Figure 8B This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0031] [ Figure 8C ] Figure 8C This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0032] [ Figure 8D ] Figure 8D This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0033] [ Figure 8E ] Figure 8E This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0034] [ Figure 8F ] Figure 8F This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0035] [ Figure 8G ] Figure 8G This is a diagram showing an example of the cross-sectional shape of the end of the first fitting part in the embodiment.

[0036] [ Figure 9A ] Figure 9A This diagram illustrates a manufacturing method based on the headpiece method.

[0037] [ Figure 9B ] Figure 9B This diagram illustrates a manufacturing method based on the cap forming method. Figure 9C ] Figure 9C This is a diagram used to illustrate a manufacturing method based on adhesive filling.

[0038] [ Figure 9D ] Figure 9D This diagram illustrates a manufacturing method based on the heat staking method. Figure 10A ] Figure 10A This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0039] [ Figure 10B ] Figure 10B This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0040] [ Figure 10C ] Figure 10C This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0041] [ Figure 10D ] Figure 10D This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0042] [ Figure 10E ] Figure 10E This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0043] [ Figure 10F ] Figure 10F This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0044] [ Figure 10G ] Figure 10G This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0045] [ Figure 10H ] Figure 10H This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0046] [ Figure 10I ] Figure 10I This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0047] [ Figure 10J ] Figure 10J This is a front view showing the shape of the base portion of the brush component from a planar perspective.

[0048] [ Figure 11A ] Figure 11A This is a front view showing a modified example of the brush section.

[0049] [ Figure 11B ] Figure 11B This is a front view showing a modified example of the brush section.

[0050] [ Figure 11C ] Figure 11C This is a front view showing a modified example of the brush section.

[0051] [ Figure 11D ] Figure 11D This is a front view showing a modified example of the brush section.

[0052] [ Figure 11E ] Figure 11E This is a front view showing a modified example of the brush section.

[0053] [ Figure 11F ] Figure 11F This is a front view showing a modified example of the brush section.

[0054] [ Figure 11G ] Figure 11G This is a front view showing a modified example of the brush section.

[0055] [ Figure 11H ] Figure 11H This is a front view showing a modified example of the brush section.

[0056] [Figure Labels]

[0057] 1…toothbrush, 2…toothbrush body, 3…brush part, 3b…gate mark, 23…head, 23a…front, 23d…back of head 23, 23A…front side recess, 23B…fitting hole (second fitting part), 23C…back side recess, 23D…through hole, 31 (31A, 31B, 31C)…brush component, 51…plate (holding part), 51d…back of plate, 51a…surface of plate 51, 52…filling part, 53…adhesive material, 70…D hardness, 311…base part, 311a…surface, 311b…back, 312 (312A, 312B, 312C)…filament, 313…first fitting part, 313a…inclined conical surface, 313b…end, 313C…locking part, θ…draft angle Detailed Implementation

[0058] The following is for reference Figures 1 to 7 To illustrate the implementation of the toothbrush in this invention.

[0059] It should be noted that the following embodiments illustrate one aspect of the present invention and do not limit the present invention; modifications can be made arbitrarily within the scope of the inventive concept. Furthermore, in the following figures, to facilitate understanding of the structures, the actual structures and the scales, quantities, etc., differ from those in each structure.

[0060] Toothbrush

[0061] The toothbrush of one embodiment will be described below with reference to the accompanying drawings.

[0062] Figure 1 This is a perspective view showing the overall structure of a toothbrush 1 according to an embodiment of the present invention. Figure 2 This is an exploded perspective view of the head 23 and brush part 3 of toothbrush 1. Figure 3 This is a perspective view showing a magnified portion of the main part of brush section 3. Figure 4 It is along Figure 1 The cross-sectional view of line IV-IV is shown. Figure 5 This is a perspective view showing an example of the configuration of the filaments 312 in the brush component 31. Figure 6 This is a perspective view showing an example of the shape of the first fitting part 313 in the brush component 31.

[0063] like Figure 1As shown, the toothbrush 1 of this embodiment includes a toothbrush body 2 and a brush part 3, which are formed into a long strip shape having a length in the axial direction.

[0064] (Toothbrush body)

[0065] like Figure 1 As shown, the toothbrush body 2 has: a handle 21 having a length along the axial direction; a neck 22 extending axially from the front end side of the handle 21; and a head 23 disposed on the front end side of the neck 22 and on the side opposite to the handle 21. Alternatively, the toothbrush 1 may have a structure in which the neck 22 is not provided between the handle 21 and the head 23.

[0066] like Figure 2 As shown, the head 23 is generally rectangular in shape when viewed from the front. The head 23 has a frontal side recess 23A that opens onto the front surface 23a. Figure 2 The front side recess 23A is a rectangular recess in the thickness direction from the front side 23a toward the head 23, and has a size that can accommodate the brush part 3.

[0067] In the head 23, a plurality of fitting holes (second fitting portions) 23B extending through the thickness direction are formed. In this embodiment, a hole array M having five fitting holes 23B arranged in the width direction of the head 23 is formed in three rows at intervals in the length direction of the head 23. Each fitting hole 23B opens toward the bottom surface 23c of the front side recess 23A and has a depth that does not reach the back surface 23d of the head 23.

[0068] In this embodiment, 15 fitting holes 23B are formed throughout the head 23, but the number of fitting holes 23B can be appropriately changed. The number and diameter of the fitting holes 23B can be set according to the number and diameter of the first fitting portion 313 of the brush portion 3 described later.

[0069] The depth of the front side recess 23A, that is, the dimension from the front side 23a to the bottom surface 23c, is approximately equal to the thickness of the base portion 311 of the brush portion 3, which will be described later. In this embodiment, the shape of the front side recess 23A in a planar view is rectangular, but it is not limited to this. It can be appropriately changed according to the shape of the base portion 311 of the brush portion 3 in a planar view.

[0070] (Brush Department)

[0071] like Figure 2 As shown, the brush section 3 is composed of multiple brush members 31. In this embodiment, it is composed of five brush members 31. The five brush members 31 constituting the brush section 3 are divided into three shapes.

[0072] Five brush members 31 are arranged in the width direction of the toothbrush 1 (brush part 3). In this embodiment, the first brush member 31A is located at the center in the width direction of the brush part 3. A second brush member 31B is arranged on both sides of the width direction of the first brush member 31A. A third brush member 31C is arranged on both sides of the width direction of the pair of second brush members 31B. In this way, the three different types of brush members 31A, 31B, and 31C are arranged in a five-fold arrangement adjacent to each other.

[0073] like Figure 2 and Figure 3 As shown, the brush components 31A, 31B, and 31C have different shapes and materials.

[0074] Polyurethane-based resins are preferably used as the soft resins for the brush components 31A, 31B, and 31C constituting the brush part 3. This ensures mechanical strength even in thin-walled areas, preventing breakage of the filaments or the first mating portion during manufacturing or use. Furthermore, polyurethane-based soft resins offer a wider range of selectable hardness compared to other elastomers. Therefore, the resin hardness can be selected based on the thickness of the molded body, taking into account usability as a toothbrush 1 (e.g., the flexibility of the filaments).

[0075] In cases where the brush can be used to remove stains from the tooth surface or massage the gums, a brush component can also be formed from a resin made by using styrene-based elastomers, ester-based elastomers, amide-based elastomers and olefin-based elastomers alone, or by properly mixing these resins, including TPU (thermoplastic polyurethane).

[0076] To ensure water resistance and antibacterial properties, ether-based polyurethanes are preferred. Ether-based polyurethanes are formulated by blending 0.01–1% by mass of any one or a combination of saturated / unsaturated hydrocarbons with a C10 or higher content, higher alcohols, fatty acid amides, fatty acid esters, low molecular weight polyethylene, PEG, fatty acid metal salts, long-chain fatty acids, fatty acid glycerols, and silicones into the polyurethane.

[0077] The preferred range for the hardness of the soft resin constituting each brush component 31A, 31B, and 31C is Shore A 90A or higher and Shore A 70D or lower. Accordingly, the brush part 3 is characterized by having a softness that does not cause pain even when the brush part 3 comes into contact with oral tissues during use, and a hardness that provides a sufficient brushing effect.

[0078] When the hardness of the soft resin is less than Shore 90A, the filaments are excessively soft and easily deform in the thin-walled sections (the tips), reducing the brushing effect. On the other hand, when the hardness of the soft resin is greater than Shore 70D, the filaments become stiff and difficult to deform; for example, the tip 23 may cause pain when it comes into contact with oral tissue. Therefore, it is preferable to use a soft resin with a hardness of Shore 90A or higher and Shore 70D or lower.

[0079] In this embodiment, a first soft resin constituting brush member 31A can be, for example, polyurethane with a hardness of 98A. A second soft resin constituting brush member 31B can be, for example, polyurethane with a hardness of 66D. A third soft resin constituting brush member 31C can be, for example, polyurethane with a hardness of 95A.

[0080] In addition, the brush part 3 of this embodiment has three brush components 31A, 31B and 31C with different shapes and materials, but it can also be configured to be a structure obtained by combining brush components 31 that are only different in shape or only different in material.

[0081] Each brush component 31A, 31B, and 31C has: a base portion 311 that is rectangular in shape when viewed from a planar perspective; a plurality of filaments 312 formed on the surface 311a of the base portion 311; and a plurality of first fitting portions 313 formed on the back side 311b of the base portion 311.

[0082] The base portion 311 has a specified thickness. For example... Figure 2 As shown, in this embodiment, the thickness of the base portion 311 is equal to the depth of the front-side recess 23A formed in the head 23. Therefore, as Figure 3 As shown, when the brush member 31 is disposed in the front side recess 23A, the surface 311a of the base portion 311 and the front side 23a of the head 23 are at the same height and form the same surface.

[0083] In this embodiment, the base portion 311 has the same shape as the brush member 31, regardless of the type of brush member 31. Furthermore, regardless of this, the shape of the base portion 311 may vary depending on the type of brush member 31.

[0084] like Figure 2 as well as Figure 3 As shown, multiple filaments 312 extend vertically outward from the surface 311a of the base portion 311. In this embodiment, two filament rows N1 and N2 are formed by the multiple filaments 312 arranged in the length direction of the base portion 311, and these filament rows N1 and N2 are arranged in the width direction of the base portion 311. The base ends of each filament 312 are connected to each other through the base portion 311, and their front ends (upper ends) are independent of each other.

[0085] In this embodiment, each filament row N1 and N2 consists of 20 filaments 312.

[0086] In adjacent filament rows N1 and N2, the filaments 312 constituting each other are aligned in the length direction of the head 23 and arranged adjacently in the width direction of the head 23. That is, the filaments 312 of one filament row N1 in the brush member 31 are adjacent to the filaments 312 of another filament row N2 in the width direction of the head 23.

[0087] like Figure 3 As shown, adjacent filament rows N1 and N2 are formed by separating each other with a gap S1 in the width direction of the head 23. Furthermore, the plurality of filaments 312 constituting filament rows N1 and N2 are also formed by separating each other with a gap S2 in the length direction of the head 23. In this embodiment, the gap S2 is wider than the gap S1 between filament rows N1 and N2, but the relationship between the sizes of gaps S1 and S2 is not limited to this. All filaments 312 extending from the surface 311a of the base portion 311 are independent of each other.

[0088] Furthermore, the number of filament rows N formed for each base portion 311 and the number of filaments 312 constituting each filament row N are not limited to the numbers shown in the figure, and can be appropriately changed according to the design of the toothbrush 1, etc. In this embodiment, two filament rows N1 and N2 are formed in the width direction of the base portion 311, but it is not limited to this.

[0089] For example, it can be set as follows: Figure 5 As shown, the filaments 312 are arranged in a so-called "staggered" structure where they are not adjacent to each other in the width direction of the base portion 311. By providing multiple filament rows in the width direction of the base portion 311, the number of filaments required for the toothbrush 1 can be ensured with a small number of brush members 31.

[0090] like Figure 3 as well as Figure 4 As shown, the shapes of the filaments 312 (312A, 312B, 312C) vary depending on the type of brush component 31 (31A, 31B, 31C).

[0091] (First brush component 31A)

[0092] The multiple filaments 312A in the first brush component 31A, such as Figure 3 As shown, there are three cylindrical parts 1a, 1b, and 1c with different diameters. These cylindrical parts 1a, 1b, and 1c are coaxial with each other, and their diameters gradually taper from the base end to the front end.

[0093] Of the three cylindrical portions 1a, 1b, and 1c, cylindrical portion 1a, located on the base (root) side of filament 312A, extends vertically from the surface 311a of the base portion 311. Cylindrical portion 1a has the largest diameter, and its diameter in the length direction is constant, so its upper end face appears circular in a planar view.

[0094] The cylindrical portion 1b, located at the center of the length direction of the filament 312A, extends vertically from the center of the upper end face of the cylindrical portion 1a. Since the diameter of the cylindrical portion 1b is smaller than the diameter of the cylindrical portion 1a, the upper end face of the cylindrical portion 1a is exposed around the cylindrical portion 1b, forming a step difference between the cylindrical portion 1b and the cylindrical portion 1a.

[0095] The cylindrical portion 1c located at the front end of the filament 312A extends vertically from the center of the upper end face of the cylindrical portion 1b. Since the diameter of the cylindrical portion 1c is smaller than the diameter of the cylindrical portion 1b, the cylindrical portion 1b is exposed around the cylindrical portion 1c, forming a step difference between the cylindrical portion 1c and the cylindrical portion 1b.

[0096] The upper end faces of cylindrical portion 1a, cylindrical portion 1b, and cylindrical portion 1c are all parallel to the surface 311a of the base portion 311. Furthermore, the radial magnitudes of the step difference formed between cylindrical portions 1a and 1b and between cylindrical portions 1b and 1c are approximately equal.

[0097] (2nd brush, component 31B)

[0098] The second brush member 31B has multiple filaments 312B, each having a triangular prism portion 2a, a triangular pyramid portion 2b, and a triangular pyramid portion 2c. The circumferential surfaces of these triangular prism portions 2a, 2b, and 2c are aligned along the length of the base portion 311, forming a side surface 2e perpendicular to the surface 311a of the base portion 311. The side surface 2e of the filament 312B is a vertical surface extending from the base of the filament 312B toward the front end, facing the front end of the head 23.

[0099] The triangular prism-shaped portion 2a stands vertically relative to the surface 311a of the base portion 311 and extends with a constant width in the length (height) direction.

[0100] The triangular pyramid portion 2b extends along its length from the top of the triangle as viewed from the plane of the triangular prism portion 2a. Of the three circumferential faces of the triangular pyramid portion 2b, the other two faces 2b1, besides the face constituting the side face 2e, are inclined relative to the length direction. These two faces are inclined toward the side face 2e from the triangular prism portion 2a toward the front end. As a result, the triangular pyramid portion 2b tapers toward the front end.

[0101] The triangular pyramid 2c is located at the front end of the filament 312B and extends in the length direction from the upper end of the triangular pyramid 2b.

[0102] (3rd brush component 31C)

[0103] The filament 312C of the third brush member 31C is formed in the following shape: the base side connected to the base portion 311 is a rectangular prism shape, which becomes thinner as it moves towards the front end. Regarding the filament 312C, its shape when viewed from the front side is rectangular, its length direction is parallel to the width direction of the head 23, and the width direction (thickness direction) of the filament 312C is parallel to the length direction of the head 23.

[0104] On one of the four outer peripheral surfaces (faces) of the filament 312C, facing the neck 22, an inclined surface 312a is formed from a predetermined position along the length (height) direction of the filament 312C towards the front end. The inclined surface 312a has a rectangular shape when viewed from the neck 22 side. Due to the inclined surface 312a, the thickness of the filament 312C gradually decreases towards the front end, becoming the thinnest at the front end. When viewed from the front side, the front end 312C of the filament 312C is formed with a thinness that is straight along the width direction of the head 23.

[0105] The other side 312d of the filament 312C is the front end side facing the head 23, and is the side opposite to the side 312b where the inclined surface 312a is formed in the thickness direction of the filament 312C. The other side 312d is a plane that extends from the base end of the filament 312C to the front end, and is a rectangular plane that is perpendicular to the surface 311a of the base portion 311.

[0106] In this embodiment, the lengths of the filaments 312A, 312B, and 312C in each brush component 31A, 31B, and 31C (the length from the surface 311a of the base portion 311 to the front end) are preferably in the range of 7 mm or more and 15 mm or less, and more preferably in the range of 9 mm or more and 13 mm or less. When the filaments 312 are too short, the operability within the brush cavity decreases. In addition, when the filaments 312 are too long, they become easily flexed, cleaning performance decreases, and demolding performance during injection molding decreases, making manufacturing difficult.

[0107] In this embodiment, the lengths of the filaments 312A, 312B, and 312C are equal among the brush members 31A, 31B, and 31C, but the lengths of the filaments 312A, 312B, and 312C in each brush member 31A, 31B, and 31C may also be different. Additionally, the lengths of the filaments 312 within the brush member 31 may also be different.

[0108] The cross-sectional area of ​​the base end side of the filament 312 is preferably 0.16 mm². 2 Above, 0.8mm 2 The following is more preferably 0.6mm 2 Therefore, proper flexing is achieved during brushing, thus improving cleaning performance.

[0109] The cross-sectional area at the base end of filament 312 is greater than 0.8 mm². 2 At this size, filament 312 becomes difficult to bend, reducing its cleaning ability in gaps such as between teeth and at the neck of teeth. On the other hand, at sizes smaller than 0.16mm... 2 Under such circumstances, it is difficult to ensure the strength of filament 312.

[0110] For example, the cross-sectional area of ​​the base end side of the first filament 312A is approximately 0.567 mm². 2 .

[0111] Additionally, for example, the cross-sectional area of ​​the base end side of the second filament 312B is approximately 0.298 mm². 2 Additionally, for example, the cross-sectional area of ​​the base end side of the third filament 312C is approximately 0.426 mm². 2 .

[0112] The cross-sectional shape intersecting the length direction of the filament 312 can be appropriately selected from polygons such as triangles and quadrilaterals, circles, and stars. Additionally, the external shape can be appropriately selected from prisms, pyramids, scraper shapes, etc. Furthermore, it can be set to a tapered shape from the base end to the front end.

[0113] (Abutment part 311)

[0114] Each base portion 311 in each brush component 31A, 31B, and 31C is rectangular in shape from a planar perspective, with its width and length dimensions being equal. In this embodiment, the ratio of the length (long side) dimension of the base portion 311 to its width (short side) dimension is 2 or more.

[0115] Specifically, such as Figure 5 As shown, the width W311 of the base portion 311 is in the range of 1 mm or more and 5 mm or less, and more preferably in the range of 2 mm or more and 4 mm or less.

[0116] The length L311 of the base portion 311 is preferably in the range of 10 mm or more and 50 mm or less, and more preferably in the range of 15 mm or more and 30 mm or less.

[0117] The thickness T311 of the base portion 311 is preferably in the range of 0.5 mm or more and 5 mm or less, and more preferably in the range of 1 mm or more and 2.5 mm or less.

[0118] On the back side 311b of the base portion 311, a plurality of (three in this embodiment) first fitting portions 313 are formed. In this embodiment, three first fitting portions 313 are formed on each brush member 31.

[0119] Each first fitting portion 313 extends vertically outward from the back surface 311b of the base portion 311. These three first fitting portions 313 are formed at equal intervals along the length of the base portion 311. The base ends of each first fitting portion 313 are connected by the base portion 311, and their lower ends (front ends) are independent.

[0120] The arrangement interval P of the first fitting part 313 Figure 5 The preferred diameter is 2mm or more and 20mm or less. In addition, the arrangement interval P of the plurality of first fitting portions 313 within a single brush member 31 may not be equal.

[0121] The first fitting portion 313 is cylindrical in shape, extending perpendicularly to the back surface 311b of the base portion 311. The diameter of the first fitting portion 313 is constant in the length direction and smaller than the width dimension of the base portion 311. The diameter D of the first fitting portion 313... Figure 4 The width of the first fitting portion 313 is preferably in the range of 1 mm to 5 mm, and more preferably in the range of 2 mm to 4 mm. Furthermore, when the first fitting portion 313 is formed of a shape other than a cylinder, and the cross-sectional shape intersecting its length direction has a minor axis and a major axis, the width of the minor axis is preferably in the range of 1 mm to 5 mm, and more preferably in the range of 2 mm to 4 mm. Similarly, the width of the major axis is preferably in the range of 1 mm to 5 mm, and more preferably in the range of 2 mm to 4 mm.

[0122] In addition, such as Figure 4 As shown, in this embodiment, the length of the first fitting portion 313 is slightly shorter than the head thickness in the portion of the front side recess 23A formed in the head 23, and is approximately the same as the depth of the fitting hole 23B. The length L313 of the first fitting portion 313 is preferably in the range of 1 mm or more and 7 mm or less, more preferably in the range of 2 mm or more and 5 mm or less, even more preferably in the range of 2.0 mm or more and 4.0 mm or less, and most preferably in the range of 2.0 mm or more and 3.5 mm or less.

[0123] Furthermore, relative to the area of ​​the bottom surface 23c of the base portion 311, the bottom area of ​​the first fitting portion 313 is preferably 10% or more and 50% or less, more preferably 30% or less, and even more preferably 25% or less. This ensures both the strength of the first fitting portion 313 and the strength of the head 23 side. When the total bottom area of ​​the plurality of first fitting portions 313 is greater than 50% of the area of ​​the bottom surface 23c of the base portion 311, the fitting hole 23B of the head 23 also becomes larger, and the strength of the head 23 side decreases sharply, which is therefore undesirable.

[0124] Furthermore, in this embodiment, the number and shape of the first fitting portion 313 can be appropriately changed. For example, such as Figure 6 As shown, the number of the first fitting part 313 can be 2 or more.

[0125] The more first fitting portions 313 there are, the better they can resist demolding resistance during manufacturing, which is therefore preferable. However, in order to take into account the strength of the head 23 side, it is preferable to set the number, shape, etc. of the first fitting portions 313 by considering the ratio of the total bottom area of ​​the multiple first fitting portions 313 to the area of ​​the bottom surface 23c of the base portion 311.

[0126] In addition, such as Figure 6 As shown, like the first fitting portion 313, the cross-sectional shape parallel to the length direction can be a cylindrical shape with a major axis and a minor axis. When only one first fitting portion 313 is provided, it is preferable to set it to an elliptical cylindrical shape. This prevents rotation around the first fitting portion 313.

[0127] Furthermore, in this embodiment, the plurality of first fitting portions 313 are arranged in a row along the length direction of the base portion 311, but they can also be arranged alternately and staggered in the width direction. That is, instead of arranging two first fitting portions 313 adjacent to each other in the width direction of the base portion 311, they are arranged alternately in a way that two first fitting portions 313 are not adjacent to each other in the width direction of the base portion 311. This allows them to be arranged without making the thickness of each first fitting portion 313 thinner, thus ensuring the strength of each first fitting portion 313.

[0128] The toothbrush 1 of this embodiment, configured in this way (each brush component 31A, 31B, 31C), is formed, for example, using the insert method.

[0129] (Manufacturing method of toothbrush 1)

[0130] Figure 7 This is a diagram illustrating the manufacturing method of toothbrush 1 in this embodiment. Figures 8A to 8G This is a diagram showing an example of the cross-sectional shape of the end portion 313b of the first fitting portion 313 in this embodiment.

[0131] First, the three brush components 31A, 31B, and 31C of this embodiment are obtained by one-time molding.

[0132] like Figure 7As shown, for each brush component 31A, 31B, and 31C, three sets of molds 40A, 40B, and 40C with different shapes are prepared (fixed-side molds 41A, 41B, and 41C, and movable-side molds 42A, 42B, and 42C). Each fixed-side mold 41A, 41B, and 41C, and each movable-side mold 42A, 42B, and 42C, has fixed-side mold cavities 41a, 41b, and 41c that reflect the shape of each brush component 31A, 31B, and 31C, and movable-side mold cavities 42a, 42b, and 42c.

[0133] The fixed-side mold cavities 41a, 41b, and 41c are mold cavities that reflect the shapes of the filaments 312A, 312B, and 312C in each brush member 31A, 31B, and 31C. The movable-side mold cavities 42a, 42b, and 42c are mold cavities that reflect the shapes of the base portion 311 and the plurality of first fitting portions 313 in each brush member 31A, 31B, and 31C.

[0134] Soft resin corresponding to brush components 31A, 31B, and 31C is injected into each mold 40A, 40B, and 40C respectively, and brush components 31A, 31B, and 31C are injection molded respectively.

[0135] After filling each mold 40A, 40B, and 40C with its respective resin material, the molded parts (brush components 31A, 31B, and 31C) are removed from each mold 40A, 40B, and 40C.

[0136] The demolding process will be explained using mold 40A as an example. The actions of mold 40A described in this article also correspond to the actions of other molds 40B and 40C.

[0137] First, by retracting the movable mold 42A from the fixed mold 41A within the mold 40A, the resin molded article (brush member 31A) is demolded from the fixed mold cavity 41a of the fixed mold 41A. Then, by sliding the ejector pin 43 inserted into the movable mold 42A relative to the movable mold 42A, the resin molded article (brush member 31A) is protruded from the movable mold cavity 42A of the movable mold 42A and demolded. In this way, the brush member 31A is removed from the mold 40A.

[0138] In this embodiment, the first fitting portion 313 has a draft angle cone surface 313a on its outer periphery. The draft angle θ of the draft angle cone surface 313a relative to the length direction of the first fitting portion 313 is preferably less than 3°, and more preferably in the range of 1° to 2°. In the case of typical soft resin molded articles, the draft angle θ is 3° or more. In contrast, in this embodiment, since the filament 312A formed on the fixed mold side 41A is thin, the draft angle θ of the first fitting portion 313 is smaller than usual in order to avoid residual demolding resistance due to close contact between the molded article and the mold.

[0139] Furthermore, in this embodiment, it is preferable to provide a protrusion and a recess at the end 313b of the first fitting portion 313 to increase the contact area relative to the front end face 43d of the mold ejector pin 43. In this way, regardless of the thickness or number of filaments of the first fitting portion 313, the demolding resistance will not be inferior to that of the filament 312 side. Examples of the shape of the end 313b of the first fitting portion 313 include... Figures 8A to 8G The shape. In particular, shapes that are easy to form and have a large contact area are preferred. Figure 8C , Figure 8D , Figure 8F , Figure 8G The cross-sectional shape of the front end face 43d of the mold ejector pin 43 is opposite to the shape of the end 313b of the first fitting part 313. The front end face 43d of the mold ejector pin 43 and the end 313b of the first fitting part 313 abut against each other without gap.

[0140] Furthermore, in this embodiment, the first fitting portion 313 is formed in a cylindrical shape. From the perspective of mold structure, the cylindrical shape of the first fitting portion 313 makes it easy to remove the molded product using the mold ejector pin 43 during demolding. In addition, even during mold processing, it is advantageous because it can be easily processed simply by pre-drilling holes, and compared to forming polygonal holes, it is not necessary to determine the orientation of the hole relative to the base portion 311 with high precision.

[0141] In addition, such as Figure 7 As shown, in order to perform injection molding with the mold 40A erected in a vertically oriented manner along the length of the molded brush member 31A (base portion 311), the nozzle 61 of the molding machine 60 contacts the lower end of the mold 40A. Therefore, in the brush member 31A injection molded using the mold 40A, for example, as... Figure 5 As shown, a gate mark 3b is formed on one end face 311c along the length of the base portion 311. Gate marks 3b are also formed on each brush member 31B and 31C in the same manner. Each gate mark 3b in each brush member 31A, 31B, and 31C is covered by the toothbrush body 2 during the secondary molding process described later, and therefore does not affect the appearance of the toothbrush 1.

[0142] Next, five brush components 31A, 31B, and 31C obtained from each of the molds 40A, 40B, and 40C are arranged and placed in the secondary mold in such a way that the brush part 3 of this embodiment is formed by combining the three types of brush components 31A, 31B, and 31C obtained from each mold 40A, 40B, and 40C.

[0143] Next, the toothbrush body 2 and brush parts 3 (each brush component 31A, 31B, 31C) are joined by injection molding using a secondary mold to obtain the toothbrush 1. On the fixed and movable sides of the secondary mold, mold cavities corresponding to the shape of the mold for the toothbrush 1 (toothbrush body 2) are formed. The brush parts 3 obtained by the primary mold are held within the secondary mold, and hard resin is injected into each mold cavity, thereby integrally injection molding the toothbrush body 2 with the brush parts 3.

[0144] In this way, the toothbrush 1 of this embodiment is manufactured by an embedding method.

[0145] In this embodiment, various treatments can be applied to each mold 40A used for forming the brush part 3 and the toothbrush body 2 to facilitate the demolding of the injection-molded product. For controlling the surface roughness of the inner surfaces of each mold cavity 41a, 42a, methods utilizing the impact of microparticles such as WPC (wood-plastic composite), Tafflat, IEPCO, shot peening, and sand blasting, as well as grinding using abrasives and electrolytic grinding, can be employed. For coating, methods such as plating, spraying, CVD (chemical vapor deposition), PVD (physical vapor deposition), and PCVD (plasma chemical vapor deposition) can be used, with film types including TiN, CrN, TiAlN, TiCN, CrSiN, TiSiN, TiBON, and AlCrSiN can be employed. In addition, it can be coated with DLC (diamond-like carbon), Teflon (registered trademark: Teflon), fluoropolymer coatings, and nitriding. Furthermore, combining the above is even better.

[0146] Alternatively, instead of injection molding the brush components 31A, 31B, and 31C separately, the entire brush part 3 can be injection molded using a single mold.

[0147] In this case, a mold is prepared to correspond to the overall forming of the brush part 3.

[0148] A single mold is used for: a fixed-side mold having a cavity reflecting the shape of the filaments 312A, 312B, 312C of the brush portion 3, which includes three brush members 31A, 31B, 31C; and a movable-side mold having a cavity reflecting the shape of the base portion of each brush member 31A, 31B, 31C and the shape of a plurality of first fitting portions 313.

[0149] First, the first soft resin is injected into the portion of the mold cavity of the fixed-side mold that reflects the shape of the first brush member 31A, and the first brush member 31A is injection molded.

[0150] Next, the second soft resin is injected only into the portion of the mold cavity of the fixed side mold that reflects the shape of the second brush member 31B, and a pair of second brush members 31B are injection molded on both outer sides in the width direction of the first brush member 31A.

[0151] Next, the third soft resin is injected only into the portion of the mold cavity of the fixed side mold that reflects the shape of the third brush member 31C, and a pair of third brush members 31C are injection molded on both outer sides of the pair of second brush members 31B in the width direction.

[0152] In this way, a brush part 3 comprising three brush components 31A, 31B, and 31C can be obtained by integral molding.

[0153] In this embodiment, injection molding is performed sequentially starting from the first brush member 31A side, but the molding order of each brush member 31 is not particularly limited. Injection molding can also be performed sequentially starting from the third brush member 31C side.

[0154] When the brush portion 3 is formed as a whole in one molding process, the end face 3c on one side in the length direction of the brush portion 3 ( Figure 2 On top, forming as Figure 5 The gate mark 3b shown is covered by the toothbrush body 2 during the secondary molding process, so it will not appear on the surface. In addition, since there is only one gate mark 3b relative to the brush part 3, the unevenness of the primary molded product is reduced, and the secondary molded product can be formed well.

[0155] In this way, the molded part (brush part 3) obtained by one molding can be integrally formed with the toothbrush body 2 by two molding processes, thereby obtaining the toothbrush 1.

[0156] <Types of manufacturing methods for toothbrush 1>

[0157] Five methods can be cited as ways to integrate the brush head 3 and the toothbrush body 2 into a toothbrush 1.

[0158] Figure 9A This diagram illustrates a manufacturing method based on the head component method. Figure 9B This is a diagram used to illustrate a manufacturing method based on capping. Figure 9C This diagram illustrates a manufacturing method based on adhesive filling. Figure 9D This diagram illustrates a manufacturing method based on thermal fusion welding.

[0159] Firstly, as a first manufacturing method, the aforementioned embedding method can be cited. As described in the above embodiment, the embedding method involves flowing resin into a space where the brush portion 3 (a comb-shaped soft resin component) is arranged within a mold and then forming it.

[0160] As a second manufacturing method, the head component method can be cited. The head component method is as follows: Figure 9A As shown, this is a manufacturing method in which each brush component 31 (brush part 3) is fixed to a separately prepared flat plate (holding part) 51 and then thermally welded to the head 23 of the toothbrush body 2. In this manufacturing method, the resins to be bonded are melted together and physically bonded by means of high-frequency welding, thermal welding, ultrasonic welding, etc.

[0161] The plate 51 has a size that fits into the recess (fitting recess) 23A of the head 23, and forms a plurality of through holes 51A. The plurality of first fitting portions 313 of each brush member 31 (brush part 3) are inserted into these through holes 51A, and the lower ends (front ends) of each first fitting portion 313 extending from each through hole 51A are fused together and solidified in a fused state.

[0162] In this manner, a connecting portion 313B is formed on the back side 51d of the plate 51 to fix each brush member 31 (brush part 3) to the plate 51. Then, each brush member 31 (brush part 3) integrated with the plate 51 is placed on the toothbrush body 2 made of hard resin and heat-fused together, thereby manufacturing the toothbrush 1. At this time, the surface 311a of the base portion 311 of each brush member 31 coincides with the surface 51a of the plate 51 and the front side 23a of the head 23.

[0163] As a third manufacturing method, the capping process can be cited. The capping process is as follows: Figure 9B As shown, a back-side recess 23C is pre-formed on the back side 23d side of the head 23 in the toothbrush body 2, which is made of hard resin. Furthermore, a brush part 3 is first provided in the front-side recess 23A on the front side 23a side of the head 23 in the toothbrush body 2. At this time, a plurality of first fitting parts 313 of the brush part 3 are inserted into each fitting hole 23B formed in the front-side recess 23A of the head 23.

[0164] Then, the filling part 52 is filled into the back side recess 23C and cured so that the lower ends (front ends) of each of the first fitting parts 313 protruding into the back side recess 23C of the head 23 are filled into each other. The filling part 52 can be a thermoplastic resin or a UV-curable resin. In the capping molding method, the toothbrush 1 is manufactured by sealing it with the filling part 52 from the back side 23d of the head 23, thereby fixing each brush member 31 (brush part 3) to the toothbrush body 2.

[0165] As a fourth manufacturing method, adhesive filling can be cited. In adhesive filling, such as... Figure 9C As shown, each brush member 31 (brush part 3) is provided in the front side recess 23A of the head 23 of the toothbrush body 2, which opens to the front side 23a.

[0166] In this manufacturing method, it is not necessary to pre-form the fitting hole 23B in the front side recess 23A of the head 23 of the toothbrush body 2. By pre-setting the depth of the front side recess 23A to the size obtained by adding the thickness of the base portion 311 and the length of the first fitting portion 313, the base portion 311 and the plurality of first fitting holes 313 can be inserted into the front side recess 23A without the base portion 311 of each brush member 31 protruding from the front side 23a of the head 23.

[0167] Before installing each brush component 31 (brush part 3), adhesive material 53 is pre-filled into the recess 23A on the front side of the toothbrush body 2, and the adhesive is allowed to cure. In this way, each brush component 31 (brush part 3) is fixed to the toothbrush body 2. The toothbrush 1 is manufactured in this manner using the adhesive filling method.

[0168] The adhesive material 53 used in the adhesive filling method is preferably a material that, after curing, provides high durability and poses no risk of harm to the human body. Examples of adhesive materials 53 include silicone-based adhesives, epoxy resin-based adhesives, polyurethane-based adhesives, and acrylic-based adhesives. Furthermore, hot-melt adhesives can also be used as the adhesive material 53.

[0169] As a fifth manufacturing method, thermal fusion welding can be cited. In thermal fusion welding, such as... Figure 9D As shown, each of the first fitting portions 313 of the brush part 3 is inserted into a plurality of through holes 23D that extend through the thickness direction of the head 23 of the toothbrush body 2. At this time, since the length of the through holes 23D formed in the head 23 is shorter than the length of each of the first fitting portions 313 of each brush member 31 (brush part 3), the lower end (front end) of the first fitting portion 313 inserted into each through hole 23D protrudes from the back side 23d side of the head 23.

[0170] By heat-melting the end portion of the protruding first fitting portion 313, a locking portion 313C extending towards the periphery of the opening of the through hole 23D is formed. The locking portion 313C has a larger opening area than the through hole 23D and locks onto the back surface 23d of the head 23. In this way, the locking portion 313C formed on the lower end side of each first fitting portion 313 locks onto the back surface 23d of the head 23, thereby forming a structure in which each brush member 31 is fixed to the toothbrush body 2, preventing the entire brush part 3 from falling out of the toothbrush body 2.

[0171] In this way, each brush member 31 is engaged with the toothbrush body 2 by heating and welding a portion of each first fitting portion 313, thus joining each brush member 31 (brush portion 3) to the toothbrush body 2 without the use of adhesive. In the heat fusion method, the toothbrush 1 is manufactured in this way.

[0172] In the hot-melt welding method, a pulse welder, ultrasonic welder, infrared welder, induction welder, or similar device is used to apply pressure to the lower end of the first fitting portion 313, which is formed of thermoplastic resin, in a hemispherical shape to plastically deform it, thereby joining it to the toothbrush body 2. Alternatively, a welding method exists where the first fitting portion 313 is melted by heating with a soldering iron heater. This method allows for the low-cost, rapid, and effective joining of each brush component 31 (brush part 3) to the toothbrush body 2.

[0173] In this way, multiple brush components 31 formed of soft resin are combined, and each brush component 31 (brush part 3) is obtained by one-time molding. Then, it is integrated with the toothbrush body 2 formed of hard resin by secondary molding, thereby manufacturing toothbrush 1. Thus, a variety of toothbrushes 1 can be realized with only a very small number of molds.

[0174] The brush member 31 of this embodiment has a plurality of filaments 312 on the surface 311a of the base portion 311 and a plurality of first fitting portions 313 on the back side 311b. When it is desired to form a brush portion 3 composed of a plurality of brush members 31 with different hardnesses, it is difficult to deal with the demolding problem with a single mold, but demolding becomes particularly easy by means of the first fitting portions 313 extending on the side opposite to the filaments 312.

[0175] In other words, in the brush member 31 of this embodiment, by setting the ratio of the average length of the plurality of first fitting portions 313 to the length of the filament 312 to a range of 0.2 or more and 1 or less, the draft angle θ of the draft cone surface 313a relative to the length direction of each first fitting portion 313 can be less than 3°. As a result, demolding resistance can be resisted in each first fitting portion 313, making it easier to demold the molded article from the mold.

[0176] According to the manufacturing method of this embodiment, the flowability of the soft resin injected into the mold can be ensured while also ensuring the demolding properties of the molded article. Therefore, the injection-molded article (brush member 31, brush part 3) can be removed from the mold while maintaining its molded state without deformation. Furthermore, the brush member 31 or brush part 3 can be continuously molded, enabling efficient manufacturing of the brush member 31 or brush part 3.

[0177] In this embodiment, the toothbrush 1 is manufactured integrally with the toothbrush body 2 during secondary molding, by integrating the brush member 31 or brush part 3, which is obtained through one-time molding. Therefore, the brush member 31 (brush part 3), which is made of soft resin, can be firmly fixed to the toothbrush body 2, which is made of hard resin. In this way, the toothbrush 1 of this embodiment, which is obtained by integrally molding the toothbrush body 2 and the brush member 31 (brush part 3), is a toothbrush that can handle the production of multiple varieties with a small number of molds.

[0178] <Variation Example>

[0179] Next, a modified example of the base portion 311 of the brush member 31 will be described.

[0180] Figures 10A to 10J This is a front view showing the shape of the base portion 311 of the brush member 31 from a planar perspective.

[0181] In the above embodiment, the base portion 311 of the brush member 31 has a rectangular shape in a planar view, but it is not limited to this and can be appropriately modified. Figures 10A to 10J This is a diagram showing an example of the shape of the base portion 311, and a diagram showing the shape of the base portion 311 from a planar perspective viewed from the front side of the toothbrush 1.

[0182] For example, it can be set as follows Figure 10A The trapezoid shown, such as Figure 10B The parallelogram shown, such as Figure 10C The isosceles triangle shown, such as Figure 10D The elliptical shape shown, such as Figure 10F The rhombus shape shown, such as Figure 10G The diamond shape shown, such as Figure 10H The serpentine shape shown, such as Figure 10E and Figure 10I The shape shown has smooth, continuous convex and concave surfaces arranged circumferentially, such as... Figure 10J The shape shown has rectangular recesses and rectangular protrusions continuously arranged in the circumferential direction.

[0183] Due to such Figure 10A and Figure 10CThe shapes shown differ along the length of the base portion 311, thus revealing its orientation. Furthermore, even with other base shapes, the orientation along the length of the base portion 311 can be indicated by adding markings, etc. Therefore, the base portions 311 can be assembled together without mistaking the orientation of the filament 312 relative to the head 23. The markings can be formed on the surface 311a of the base portion 311, or on its side.

[0184] Next, a modified example of brush part 3 will be described.

[0185] Figures 11A to 11H This is a front view showing a modified example of brush part 3.

[0186] In the above embodiment, the brush section 3 is composed of five brush members 31, but the number of brush members 31 constituting the brush section 3 is not limited to five and can be appropriately changed. For example... Figures 11A to 11H As shown, for example, it can be composed of four or fewer brush members 31, or it can be composed of six or more brush members 31.

[0187] In addition, such as Figures 11A to 11H As shown, the types (shapes) of the brush members 31 constituting one brush section 3 are not limited to three, and can be two or less. Figure 11G ( ), or there can be four or more types. Furthermore, the types of all the brush members 31 constituting the brush section 3 can be different from each other. Conversely, the types of brush members 31 constituting the brush section 3 can all be the same ( Figure 11H ).

[0188] Here, as for the types of brush components 31, in addition to differences in shape such as appearance or filament length, multiple variations can be obtained by changing at least one or more of the settings for different items such as color, material, and resin hardness, or by changing combinations thereof. Furthermore, the toothbrush size can also be varied by changing the length of the head 23.

[0189] Furthermore, the arrangement of the plurality of brush members 31 constituting the brush section 3 is not limited to the arrangement described in the above embodiment, and can be appropriately modified. In the above embodiment, the length direction of each of the five brush members 31 is parallel to the length direction of the head 23, and a plurality of them are arranged in the width direction of the head 23 (longitudinal arrangement), but it is not limited to this arrangement.

[0190] For example, it can be like Figure 11A As shown, the brush members 31 are arranged with their length direction set perpendicular to the length direction of the head 23. Alternatively, they can be arranged as follows: Figure 11B As shown, the brush members 31 are arranged with their length direction inclined relative to the length direction of the head 23. Alternatively, as... Figure 11CAs shown, the brush portion 3 is formed by combining the following portions: a portion in which the length direction of the brush member 31 is arranged longitudinally parallel to the length direction of the head 23; and a portion in which the length direction of the brush member 31 is arranged laterally perpendicular to the length direction of the head 23 at the front end side and the rear end side of the head 23, respectively, by clamping the length directions of the longitudinally arranged portions.

[0191] Furthermore, the arrangement of the multiple brush components 31 constituting a brush unit 3 can be appropriately combined from longitudinal, transverse, and oblique arrangements.

[0192] Furthermore, in the above embodiment, the dimensions of the plurality of brush members 31 constituting the brush portion 3 in the longitudinal direction are equal to each other, but this is not a limitation. For example, it may be as follows: Figure 11D , Figure 11G As shown, the lengths of the brush members 31 arranged on both sides of the head 23 in the width direction are shorter than the lengths of the brush member 31 arranged in the center of the head 23 in the width direction. Additionally, it can be as follows... Figures 11A to 11C , Figure 11H As shown, brush members 31 shorter than the plurality of brush members 31 disposed in the center are disposed on the front end side and the rear end side of the head 23. In addition, since the brush members 31 are formed of soft resin, the rectangular base portion 311 can be deformed into, for example, an arc shape and disposed on the head 23 which is formed of hard resin.

[0193] Can Figure 11C , Figure 11F , Figure 11G and Figure 11H As shown, the length varies depending on the type of brush component 31 or its position in the head 23.

[0194] Can Figure 11E , Figure 11F As shown, the brush part 3 is formed by appropriately combining the brush component 31 and the elastic body part 71 (or bristle bundle part 72) formed by multiple bristles.

[0195] Can Figure 11E As shown, the brush portion 3 is formed by combining the following portions: a first portion R1, in which a plurality of brush members 31 are arranged in a posture in which their respective length directions intersect the length direction of the head 23; and a second portion R2, in which a plurality of hair bundle portions (elastic body portions) are arranged in the length direction on both sides of the head 23 in the width direction and on both sides of the first portion R1.

[0196] Here, in each brush component 31, the lengths are equal and the multiple filaments 312 are arranged in an alternating pattern, but this is not the only case.

[0197] In addition, it is possible to Figure 11FAs shown, the brush portion 3 is formed by mixing the following portions: a second portion R2, wherein a plurality of bristle bundles 72 (elastic body portions 71) are arranged in the center of the head 23; and a first portion R1, wherein a plurality of brush members 31 are arranged in a manner surrounding the second portion R2.

[0198] In this way, by setting a structure in which a first part R1 (in which a plurality of brush members 31 are arranged) and a second part R2 (in which a plurality of elastomer parts 71 (or bristle tufts 72) are arranged in a single brush part 3, cleaning performance can be ensured in the first part R1, and massage and whitening effects can be improved in the second part R2.

[0199] Additionally, it can be applied to toothbrushes that are not in the usual toothbrush head shape but have only a head 23 and no handle 21. Furthermore, multiple brush components 31 can be provided on a base such as a finger cot or a mouthpiece.

[0200] As described above, the toothbrush 1 of this embodiment and its variations are formed with the following structure: multiple brush members 31 made of soft resin are combined to form a brush part 3, and each brush member (brush part 3) made of soft resin and the toothbrush body 2 made of hard resin are integrally formed. By appropriately changing the combination of brush members 31 with different shapes, various types of toothbrushes 1 can be manufactured. Furthermore, for example, by appropriately combining the hardness or color of the soft resin constituting the brush member 31, since the brush member 31 is made of soft resin, it can also be deformed and assembled into the head 23 in the hard toothbrush body 2. More brush members 31 can be manufactured using one mold. In this way, the design range of the toothbrush 1 can be expanded without increasing the number of molds, and various types of toothbrushes 1 suitable for most users can be realized at low cost.

[0201] Furthermore, since the multiple brush components 31 (brush parts 3) formed of soft resin are integrated with the toothbrush body 2 formed of hard resin by the various methods described above, the brush parts 3 will not fall off from the toothbrush body 2 during use and can be used for a long time.

[0202] The above is with reference to the appendix. Figure 1 While the preferred embodiments of the present invention will be described, it goes without saying that the present invention is not limited to these examples. The shapes, combinations, etc. of the constituent components shown in the above examples are just examples, and various modifications can be made according to design requirements, etc., without departing from the spirit of the present invention.

[0203] In the above embodiment, in the injection-molded brush component, a gate mark 3b is formed on one end face 311c in the length direction of the base portion, but the position of the gate mark 3b is not limited to this position.

[0204] In the above embodiment, the end portion 313b of the first fitting portion 313 on the side opposite to the base portion 311 is formed in a concave-convex shape, but it is not limited to this and may be flat.

Claims

1. A toothbrush, characterized in that, have: A brush portion having multiple brush components, wherein the multiple components are 4, 5, or 6; and The toothbrush body has the brush head integrally formed on the front of the head. The brush member formed from a soft resin with a D hardness of 70 or less has: abutment part; Multiple filaments formed on the surface of the base portion; and A first fitting portion is formed on the back side of the base portion and fits into the toothbrush body. The brush component or the brush part is formed from the soft resin in a single molding process. The toothbrush body, formed of hard resin, has a second fitting portion that fits into the first fitting portion. The brush is constructed by arranging multiple brush components that have any one or more different characteristics, including the hardness of the soft resin, the length of the filament, the shape of the filament, the color of the filament, and the type of soft resin. The base portion is unrelated to the type of brush component and has the same shape.

2. The toothbrush according to claim 1, wherein, The first fitting portion is formed on the back side of the base portion, opposite to the surface on which the plurality of filaments are formed. The ratio of the length of the first fitting portion from the back side to the length of the filament from the surface side is 0.2 or more and 1.0 or less.

3. The toothbrush according to claim 1 or 2, wherein, The first fitting part is cylindrical.

4. The toothbrush according to claim 1 or 2, wherein, In the injection-molded brush component, The first fitting part has a draft angle conical surface on its outer periphery. The draft angle θ of the draft cone surface relative to the direction perpendicular to the back surface is less than 3°.

5. The toothbrush according to claim 1 or 2, wherein, The brush portion has: The plurality of brush components; and The holding portion that holds the first fitting portion of each of the plurality of brush components, The plurality of brush components are inserted into the plurality of first fitting portions from the front side of the retaining portion through a plurality of through holes in the thickness direction of the retaining portion, and are interconnected on the back side of the retaining portion. The retaining part is disposed in the front side recess of the front opening of the head.

6. The toothbrush according to claim 1 or 2, wherein, The toothbrush has a filling portion that connects the first fitting portions of each of the plurality of brush members. The toothbrush body has a dorsal side recess with an opening on the back of the head. The filling portion is formed in the recess on the back side.

7. A method for manufacturing a toothbrush, characterized in that, The process includes: a step of molding a brush portion having multiple brush members formed from a soft resin with a D hardness of 70 or less, wherein the multiple members are 4, 5, or 6; and The process of integrally forming the brush head and the toothbrush body. In the process of manufacturing the brush part The brush member is formed in one step from the soft resin, and the brush member has: a base portion, a plurality of filaments formed on the surface of the base portion, and a first fitting portion formed on the back side of the base portion and fitting into the toothbrush body. The brush is constructed by arranging multiple brush components that have any one or more different characteristics, including the hardness of the soft resin, the length of the filament, the shape of the filament, the color of the filament, and the type of soft resin. The base portion is unrelated to the type of brush component and has the same shape. In the process of integrally forming the brush head and the toothbrush body, The toothbrush body is formed from hard resin, and the toothbrush body has a second fitting portion that fits into the first fitting portion.

Images