JP3524306B2 - Toothbrush handle and its injection mold - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothbrush handle and its injection mold.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 12, a toothbrush is manufactured by implanting bristles on a handle a which is a resin molded product, and the handle a has a rod-shaped grip portion b to be gripped by a user. A head portion d is integrally formed at the tip of the grip portion b via a neck portion c. On one surface side of the head portion d, a plurality of hair transplant holes f in which a plurality of hair bundles e are embedded are arranged, and the base portion of the hair bundle e is formed by using a flat wire (metal piece) g. The brush portion is formed by fixing the brush portion.

As shown in FIG. 13A, the flock holes f of the head part d are regularly arranged on one surface of the head part d, and these flock holes f are formed at the time of injection molding of the handle a. Molded at the same time. Specifically, as shown in FIG. 13B, a plurality of mold pins i inserted into the mold body h are projected into the cavity j, and resin is filled around the plurality of mold pins i. Then, a plurality of flock holes f are formed simultaneously with the head d.

As shown in FIG. 13 (c), the plurality of mold pins i are independent pins, and a flange portion i1 having a diameter larger than the pin diameter is provided at one end thereof. .
The die pin i is incorporated into the die body h at the same time as the amount of protrusion in the cavity j is regulated by fitting the flange portion i1 into the concave portion k1 of the die body h.

The cross-sectional shape of the mold pin i, that is, the flocked hole f
13A is generally used as a plane shape, but in addition to this, a square shape is also used (see Japanese Utility Model Publication 62-374).
No. 78, 58-3826, 61-778
28, JP-A-61-76104, JP-A-61-24
0911, Japanese Patent Laid-Open No. 5-228019),
Various shapes such as a rhombus (see Japanese Utility Model Publication No. 7-15205) and a hexagon (see Japanese Patent Application Laid-Open No. 60-241405) have been proposed.

[0006] In this type of toothbrush, as a method of improving the brushing property and the feeling of brushing, a method of forming the cross section of the bristles e into a great circle or an ellipse as compared with a normal circle to achieve dense bristling Alternatively, there may be mentioned a method of adopting square or rectangular flock holes f of approximately the same size as the cross section of a normal tuft e and narrowing the f hole holes f to achieve dense flocking.

In the case of the method of making the flock holes f square or rectangular, theoretically, the bristles can be formed more densely by filling the fuzz holes f and f as close as possible.
Then, in order to narrow the distance between the flocked holes f, f, the mold pins i, i for molding the flocked holes f, f are brought close to each other, that is, the pin holes m, m in the mold body h (see FIG. ) See).

[0008]

However, considering the strength and durability of the mold body h, a certain distance is required between the pin holes m of the mold pins i. For this reason, there is a limit to densely implanting the brush portion by a method of narrowing the space between the flocked holes f. Further, conventionally, since the mold pins i are inserted into the mold body h independently of each other, it is necessary to form the flange parts i1 on all the mold pins i, and the large-diameter flange parts i1 are also used. The interval between the flocked holes f is restricted.

Further, since it is necessary to form the same number of pin holes m as the plurality of die pins i in the die body h, there is a problem that the machining cost of the die increases.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to arbitrarily bring the hair-implanted holes closer to each other without affecting the strength and durability of the mold body. An object of the present invention is to provide a toothbrush handle and an injection mold for the toothbrush, which can improve the brushing property and the feeling of brushing of the toothbrush by improving the dense flocking and can reduce the cost of the mold processing.

[0011]

The present invention has the following constitution in order to achieve the above object. The toothbrush handle according to claim 1, wherein an injection molding die including a pair of die bodies having a cavity formed therein and an insertion hole formed in one of the die bodies is directed toward the cavity. At least one block inserted,
A plurality of mold pins protruding into the cavity are formed on the tip surface of the block, and a metal mold in which the block is inserted is formed on the end surface opposite to the tip surface on which the mold pins are formed. A head that is formed integrally with a grip portion by using a thermoplastic resin by a plurality of mold pins formed in the block when a collar portion that fits into the recess of the mold body is formed and is injection molded by an injection molding mold. The feature is that a plurality of flocked holes are formed in the portion.

In the toothbrush handle according to a second aspect of the present invention, the plurality of flocked holes are arranged adjacent to each other at intervals of 0.2 (mm) or more.

In the toothbrush handle according to a third aspect of the present invention, the plurality of flocked holes are arranged in the toothbrush longitudinal direction, the toothbrush width direction, or a combination thereof.

According to a fourth aspect of the present invention, there is provided an injection-molding die for molding a toothbrush handle having a plurality of hair-implanted holes in a head portion integrally formed with a grip portion by using a thermoplastic resin. And a pair of mold bodies formed on one side of the mold body, and at least one block inserted into the insertion hole formed in one of the pair of mold bodies toward the cavity. Has a plurality of mold pins protruding into the cavity at this tip surface, and at the end surface opposite to the tip surface on which these mold pins are formed, It is characterized in that a collar portion that fits into the recess is formed.

In the injection-molding die according to claim 5, the plurality of die pins are arranged adjacent to each other at intervals of 0.2 (mm) or more.

According to a sixth aspect of the injection molding die, the plurality of die pins are arranged in the toothbrush longitudinal direction, the toothbrush width direction, or a combination thereof.

According to the present invention, since a plurality of mold pins are provided so as to project from the tip end surface of one block incorporated in the mold body, the intervals between the plurality of mold pins are determined by the tips of the blocks. On the surface, it can be freely set regardless of the strength and durability of the mold body. Therefore, slits can be provided in the longitudinal direction or the horizontal direction on the tip end surface of the block, and a plurality of mold pins can be formed by these slits, whereby the intervals between the mold pins can be set as narrow as possible. As a result, it is possible to form a brush portion that is densely transplanted, so that it is possible to improve the cleaning performance and the actual feeling of cleaning of the toothbrush. For example, it is possible to obtain a toothbrush with good cleaning efficiency by setting the interval between adjacent mold pins (interval between flocked holes) to 0.2 (mm) or more.

Further, in the present invention, since a plurality of mold pins can be projected in the cavity by incorporating one block, the distance between the flange portions of the mold pins is taken into consideration as in the conventional case. There is no need.

Further, by setting the cross-sectional shape of the mold pins (planar shape of the flocked holes) to be a square, a rectangle, a trapezoid, a parallelogram, a hexagon, or a combination thereof, a plurality of mold pins can be packed. It is possible to arrange the brush portions, and it is possible to obtain a brush portion in which the bristles are further densely transplanted.

Further, since it is sufficient to form only the block insertion holes in the mold body, there is a gap between the flocking holes which are intermittently connected.
Regardless of the strength and durability of the mold, the mold can be formed at an arbitrary interval and the cost of the mold processing can be reduced.

The hair-implanted holes formed by the mold pins according to the present invention may be applied to all the hair-implanted holes formed in the head portion, or may be applied to some hair-implanted holes. For example, depending on the purpose of the toothbrush, the flocked hole according to the present invention and the conventional flocked hole (for example, a circular flocked hole formed by a mold pin independently inserted into the mold body) can be combined.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments (first to seventh embodiments) of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the first embodiment is an injection mold for molding the toothbrush handle 2 using a thermoplastic resin, and a block 6 is formed in the mold body 4a toward the cavity E. And a plurality of die pins 8 projecting into the cavity E are arranged on the tip end surface of the block 6, and a plurality of flocked holes 10 are formed in one block 6 by the die pins 8 by the toothbrush handle 2 The head portion 2a is molded. A grip portion (not shown) is integrally formed with the head portion 2a via the neck portion 2b as in the conventional case.

The mold comprises upper and lower mold bodies 4a and 4b having a cavity E formed therein, and one mold body 4a.
The substantially rectangular block 6 is inserted into the insertion hole 4a1.
The block 6 has a flange portion 6a on the end surface on the side opposite to the die pin 8 side, which is fitted in the recess 4a2 of the die body 4a. The plurality of mold pins 8 are formed by the plurality of slits S having a constant depth formed on the tip end surface of the block 6 so that each of the mold pins 8 has a square cross section. In the first embodiment,
As shown in FIGS. 3 and 4, the plurality of mold pins 8 form a plurality of square flocked holes 10 adjacent to each other in a direction orthogonal to the longitudinal direction of the toothbrush (hereinafter referred to as “toothbrush width direction”).

Width of slit S (distance between mold pins 8 and 8)
That is, the interval P between the flocked holes 10, 10 is 0.2 (m
m) or more. Regarding the structure of the block 6, a large number of mold pins 8 can be formed by forming all the mold pins 8 on the tip surface of one block or by arranging seven plate-shaped blocks in parallel in the toothbrush longitudinal direction. Flock holes 10 can be formed. Also, the mold pin 8
By rounding the corners of the
A rounded portion 10a may be provided at a corner portion of the flocked hole 10. Moreover, the size of the flocked hole 10 is 1.5 to 3.5 (mm ² ).
However, 2.0 to 3.0 (mm ² ) is more preferable in consideration of the usability, the cleaning property and the manufacturability of the toothbrush. The molding material of the toothbrush handle 2 may be a thermoplastic resin, such as polypropylene, polyethylene, polyester, polyamide, polymethylmethacrylate, cellulose propionate, acrylonitrile-styrene, acrylonitrile-butadiene-styrene resin. It is possible. The dimension of the interval P, the configuration of the block 6, the size of the bristle hole 10, and the molding material of the toothbrush handle 2 are the same for the second to seventh embodiments described later.

According to the first embodiment as described above, since the plurality of mold pins 8 are provided at the tips of the blocks 6 inserted into the mold body 4a, the adjacent mold pins 8, The interval P between the 8 can be freely set on the tip surface of the block 6 regardless of the strength and durability of the mold body 4a, but if the interval P between the hair-implanting holes 10 is too thin, The partition wall 11 is pressed by the pressure when the hair is planted in the hole 10 with a flat line.
(See FIG. 3) may be deformed or destroyed, and there may be a problem when the adjacent flocked holes 10 are flocked. Therefore, the interval P is preferably 0.2 (mm) or more.

Further, by incorporating one block 6,
Since a plurality of mold pins 8 can be projected into the cavity E, it is not necessary to consider the distance between the flange portions of the mold pins as in the conventional case. Further, since only the insertion hole 4a1 (see FIG. 1) of the block 6 needs to be formed in the die body 4a, the cost of die machining can be reduced.

Next, the second to fourth embodiments will be described.
The second to fourth embodiments are examples in which the block and the mold pin according to the present invention are used, and as shown in FIGS.

In the second embodiment, as shown in FIG. 6, a block having a plurality of isosceles trapezoidal mold pins at its tip is used to form a plurality of isosceles trapezoids on the hair-implanted surface of the head portion 2a. This is an example in which the pores 12 are alternately formed adjacent to each other in the width direction of the toothbrush at the interval P, and a pair of circular flock holes f are formed at both ends in the longitudinal direction of the toothbrush as in the conventional case.

In the third embodiment, as shown in FIG. 7, a block having a plurality of hexagonal mold pins on its tip surface is used to form a plurality of hexagonal hair-planting holes on the hair-implanting surface of the head portion 2a. 1
An example in which 4, 16 (the flocked holes 14 are hexagons with one indented inside and the flocked holes 16 are normal hexagons with all the raised sides) are adjacent to each other in the toothbrush width direction at the interval P. Is. In this embodiment, the plurality of mold pins are configured such that the concave corners of the flocked holes 14 and the convex corners of the flocked holes 14 or the corners of the flocked holes 16 face each other.

In the fourth embodiment, as shown in FIG. 8, a head portion 2a is used by using a die pin having a shape in which one side of a rectangle is a semicircle and a block having a rectangular die pin on its tip surface. On the flocked surface of, a flocked hole 1 with one side of the rectangle being a semicircle
8 and rectangular flock holes 20 are formed adjacent to each other at the interval P in the toothbrush width direction. In this embodiment, the sides of the flocked holes 18 are adjacent to each other, the sides of the flocked holes 20 are adjacent to each other, or the flocked holes 18 are adjacent to each other.
And the side of the flocked hole 20 are adjacent to each other.

As can be seen from these second to fourth embodiments, quadrangles other than squares (trapezoid, parallelogram, rhombus, etc.)
Alternatively, even with a hair-planting hole such as a hexagonal polygon, if the block and the mold pin according to the present invention are appropriately configured, adjacent hair-planting holes can be arranged close to each other.

Next, a fifth embodiment will be described. In the fifth embodiment, as shown in FIG. 9A, a plurality of flock holes 18, 20 are formed adjacent to each other at the interval P only at both ends of the head portion 2a in the toothbrush longitudinal direction. A circular flock hole f is formed in the central portion of the head portion 2a as in the conventional case. With this configuration, so-called "toe polishing" (Fig. 9)
(B), cleaning with the front end side hair bundle 22a shown in (c)) and "heel polishing" (cleaning with the rear end side hair bundle 22b shown in FIGS. 9 (b) and (c)) Since a suitable toothbrush can be obtained, the cleaning effect on the back teeth and the back side of the teeth is further improved as compared with the conventional flocked toothbrush. The bristling shape of the brush portion 22 in this case is not limited to the flat shape as shown in FIG. 9B, but as shown in FIG.
Alternatively, the hair bundles 22a and 22b at the front and rear ends may be elongated by recessing the central portion of the.

In the sixth embodiment, as shown in FIG. 10 (a), a plurality of square flocked holes 10 are adjacent to each other in the toothbrush width direction at the intervals P at the toothbrush width center of the flocked surface of the head portion 2a. On the other hand, at both ends of the flocked surface in the toothbrush width direction, a plurality of rectangular flocked holes 20 are adjacent to each other at intervals P in the longitudinal direction. According to the sixth embodiment, it is possible to further enhance the cleaning effect between the teeth and the gum by using the plurality of bristles 22c adjacent to each other in the longitudinal direction of the toothbrush (outer portion of the brush portion 22). In addition, the bristle cutting shape of the brush portion 22 in this case is not limited to the shape in which the bristles are aligned as shown in FIG. 10B, but as shown in FIG. The bristle bundle 22c may be projected and the tip thereof may be formed in a hemispherical shape.

The seventh embodiment is shown in FIGS. 11 (a) to 11 (c).
As shown in FIG.
Each bristle bundle 22 which is formed on the flocked surface of a so as to be adjacent in the toothbrush width direction at the interval P and is embedded in each flocked hole 20.
The tip of d is formed in a substantially mountain shape, and the bristle cutting shape of the brush portion 22 is a so-called "mounting cut" shape. Figure 1
The tip shape of each hair bundle 22d shown in FIG. 1 (b) is obtained by cutting only one side in the front-rear direction into a slope shape, and the tip shape of the hair bundle shown in FIG. 11 (c) is cut into both front and rear sides in a slope shape. It was done. In this way, the plurality of hair bundles 22d are arranged adjacent to each other at the interval P, and the brush portion 22 is formed into a “mounting cut” shape. The degree of penetration can be increased, and the cleaning effect can be further improved.

The present embodiment is a preferred embodiment of the present invention, and the technical scope of the present invention is not limited to this embodiment.

[0036]

According to the present invention, the following effects can be obtained. The intervals between the plurality of mold pins can be freely set on the tip surface of the block regardless of the strength and durability of the mold body. Therefore, slits can be provided in the longitudinal direction or the horizontal direction on the tip end surface of the block, and a plurality of mold pins can be formed by these slits, whereby the intervals between the mold pins can be set as narrow as possible.

As a result, it is possible to form a more densely-planted brush portion, so that it is possible to improve the cleaning performance and the actual feeling of cleaning of the toothbrush. For example, it is possible to obtain a toothbrush with good cleaning efficiency by setting the interval between adjacent mold pins (interval between flocked holes) to 0.2 (mm) or more.

By inserting one block, a plurality of mold pins protruding into the cavity can be obtained, so that it is not necessary to consider the interval between the flange portions of the mold pins as in the conventional case.

Since only the block insertion holes need to be formed in the die main body, the gaps between the flocked holes that are intermittently connected can be formed at arbitrary intervals regardless of the strength and durability of the die, and The cost of mold processing can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an injection molding die according to a first embodiment.

FIG. 2 is a perspective view of a block according to the first embodiment.

FIG. 3 is a plan view of a head unit according to the first embodiment.

FIG. 4 is an enlarged view of part A in FIG.

FIG. 5 is an enlarged view of a hair-implanted hole according to a modified example of the first embodiment.

FIG. 6 is a plan view of a head section according to the second embodiment.

FIG. 7 is a plan view of a head unit according to a third embodiment.

FIG. 8 is a plan view of a head section according to the fourth embodiment.

9A is a plan view of a head portion according to a fifth embodiment, FIG. 9B is a view as seen from an arrow B in FIG. 9A, and FIG. 9C is a modification of the fifth embodiment. It is a B arrow line view in a).

10A is a plan view of a head portion according to a sixth embodiment, FIG. 10B is a view taken in the direction of arrow C in FIG. 10A, and FIG.
It is a C arrow line view in (a) concerning the modification of a 6th embodiment.

11A is a plan view of the head portion according to the seventh embodiment, FIG. 11B is a view on arrow D in FIG. 11A, and FIG.
It is a D arrow line view in (a) concerning the modification of a 7th embodiment.

FIG. 12 is an exploded perspective view of a toothbrush according to a conventional example.

FIG. 13A is a plan view of a head portion according to a conventional example,
(B) is a cross-sectional view of an injection molding die according to a conventional example, (c).
FIG. 6 is a perspective view of a plurality of mold pins.

[Explanation of symbols]

2 toothbrush handle 2a head part 4a, 4b Mold body 6 blocks 8 mold pins 10 hair transplant holes 12 hair transplant holes 14,16 Flock holes 18,20 Flock holes E cavity P Mold pin interval (Foam hole interval)

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Claims (6)

(57) [Claims] 1. A pair of molds having a cavity formed therein.
Of the injection molding dies consisting of the main body and those mold bodies
Towards the cavity in the insertion hole formed in one of the
At least one block to be inserted, said block protruding into the cavity at its tip surface
Forming multiple mold pins that
On the end face opposite to the tip face where the mold pin is formed,
The collar part that fits into the concave part of the mold body
When the injection molding die is used for injection molding,
Thermoplastic resin due to multiple mold pins formed on the lock
Heads integrally molded with the grip using the
Toothbrush handle characterized by having holes formed . 2. The toothbrush handle according to claim 1, wherein the plurality of hair-implanted holes are arranged adjacent to each other at intervals of 0.2 (mm) or more. 3. The toothbrush longitudinal direction of the plurality of hair transplant holes
Or the toothbrush width direction or the direction that combines them
Claim 1 or 2 toothbrush handle wherein that you have been arranged. 4. An injection molding mold for molding a toothbrush handle having a plurality of flocked holes in a head part integrally molded with a gripping part by using a thermoplastic resin, and a pair of mold bodies having a cavity formed therein. , This one
In the insertion hole formed in one of the pair of mold bodies
At least one block inserted into the cavity
The above-mentioned block has a protrusion and is protruded into the cavity at this tip surface.
Forming multiple mold pins that
On the end face opposite to the tip face where the mold pin is formed,
The collar part that fits into the concave part of the mold body
Injection mold of the toothbrush handle, characterized in that there. 5. The plurality of mold pins are 0.2 (mm)
The injection molding mold for a toothbrush handle according to claim 4, wherein the injection molds are arranged adjacent to each other at the above intervals. 6. The toothbrush longitudinal direction includes a plurality of mold pins.
Direction or toothbrush width direction or one that combines them
The injection mold for a toothbrush handle according to claim 4 or 5, wherein the molds are arranged in a direction .