JPH09327334A - Manufacture of interdental brush and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an external appearance grade by making a filament body embedded inside unable to see through from outside in an interdental brush formed so as to easily remove an eating residue between teeth. SOLUTION: In this manufacturing method, a brush wire stem 2 composed of a twisted wire to which a brush 1 is fixed is integrally connected by an inmold to a handle 3 molded by a molding metal mold. In this case, at least opposed one of plural projecting bodies oppositely arranged at intervals in a handle molding space of the molding metal mold 4 so as to project in the central direction, is brought into contact with the peripheral side of the brush wire stem 2, and a base end part 21 of the brush wire stem 2 is held in an almost central part of the handle molding space, and the handle 3 is formed by injection molding, and is formed as an interdental brush 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an interdental brush for cleaning a space between teeth and a molding apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, as an interdental brush that easily fits in a pocket or the like, two folded wires are twisted together and a brush is sandwiched between them to form a brush, and the end of the wire is a plastic handle. Those embedded in are commercially available. For example, as disclosed in Japanese Utility Model Publication No. 6-33853, the tip of the tapered handle body is strongly deformed with a finger by brushing the tip of the protruding metal wire embedded in the handle. Then, the brush portion is inserted into the gap between the teeth and brushed. By the way, in order to manufacture this product, for example, the base end portion a ₁ of the metal wire a on which the brush b is implanted is positioned inside the tip end portion of the handle body d and injection molding is performed. Since the injection pressure of the material in the molding process in which the resin material is press-fitted is extremely strong, the thin metal wire cannot withstand this pressure, and the base end portion a ₁ of the metal wire a deviates and is almost in contact with the mold surface. In such a state, the metal wire is seen through, or it pops out, which is bad for the appearance and causes a trouble in handling.

[0003]

Therefore, in the prior art, as shown in FIG.
As shown in 0, a brush b is used by using a slide core in the mold.
The base end portion of the metal wire in which the hair is planted can be loosely fitted in the center portion c so that the base end portion a ₁ of the metal wire a is not seen through in the handle body d after molding. , As a result of using the slide core as a part of the mold even with this improved type,
There are problems that the mold becomes complicated and it is difficult to mount the brush wire stem in the mold, the workability is poor, and the mold becomes expensive. The present invention is intended to eliminate these conventional drawbacks, in which the brush wire stem is accurately embedded in the handle central portion and does not appear on the outer surface of the handle, and even if it appears, it does not damage the appearance. It is an object of the present invention to provide an interdental brush manufacturing method capable of greatly improving the above-mentioned, and a molding die device of a useful and inexpensive form used for the manufacturing.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method of manufacturing an interdental brush in which a brush wire stem made of a twisted wire to which a brush is fixed is integrally connected in-mold to a handle formed by a molding die. At least one of a plurality of projecting bodies provided to face each other in the handle forming space so as to project in the center direction and to abut the circumferential side of the brush wire stem. The brush wire stem and the handle are integrally formed by injection-molding the handle while holding the end portion at substantially the center of the handle forming space. Further, the present invention is an interdental brush molding die for molding a handle by in-molding by inserting a proximal end portion of a brush wire stem made of a twisted wire to which a brush is fixed into a handle molding space. A plurality of protrusions protruding to the vicinity of the central axis of the space are provided on the inner surface of the opposing molding die at intervals in the longitudinal direction, and protrusions or contact pins protruding in a direction intersecting with the protrusions are provided. It is characterized by that.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiment of the present invention, at least one of a plurality of projecting bodies provided in the handle forming space of a molding die so as to project in the center direction with a space therebetween is opposed to the brush. The handle is injection-molded by holding the base end of the brush wire stem substantially at the center of the handle molding space so that it abuts the peripheral side of the wire stem. Even if the injection pressure of the resin material is applied to the end portion, the brush wire stem is positioned in a state of being sandwiched by the tips of the intersecting protrusions, and the groove formed by the brush wire stem and the protrusion is formed. The valley part of the wire is about point contact, and most of the brush wire stem is embedded in the center of the handle, so the base end of the metal wire can be seen through the handle body after molding. Gana Appearance a good interdental brush quality. Further, in this interdental brush forming die device, a plurality of protruding bodies protruding to the vicinity of the central axis of the handle forming space are provided on the inner surface of the opposing forming die at intervals in the longitudinal direction, and the protruding bodies are intersected with each other. By providing a protruding body or a contact pin that projects in the direction of, the base end portion of the brush wire stem is positioned in the center of the molding space of the injection molding die,
Even if the resin material is press-fitted into the mold, the base end of the brush wire stem comes into contact with the projecting body that receives the pressure and is temporarily supported. Since it will be filled up to the inner surface of the mold if it is between the bodies, the base end of the brush wire stem will not come into contact with the inner surface of the mold. Since the base end is not located,
An interdental brush having a good appearance can be manufactured without being seen through from the outside.

[0006]

1 to 4, a brush wire stem 2 made of a twisted wire to which a brush 1 is fixed is integrated with a handle 3 molded by a molding die 4 by in-molding. In the method for manufacturing a connected interdental brush, at least one of a plurality of projecting bodies 6 provided facing each other in the handle molding space 5 of the molding die 4 so as to project in the center direction at intervals is the brush. so as to abut against the periphery of the wire stem 2 and interdental brush 10 of the handle 3 to hold in a substantially central portion by injection molding of the handle molding space proximal portion 2 ₁ of the brush wire stem 2.

[0007] In this case, when manufacturing the interdental bristle for molding the handle 3 in-mold by inserting the proximal end 2 ₁ of the brush wire stem 2 consisting of twisted wire was fixed to the brush 1 to the handle molding space 5 Mold 4,
A plurality of protrusions 6 protruding to the vicinity of the central axis of the handle forming space 5 are provided on the inner surfaces of the opposing molding dies at intervals in the longitudinal direction, and the protrusions projecting in a direction intersecting with the protrusions 6, or A device provided with the contact pins 7 is preferably used as an interdental brush manufacturing apparatus.

Accordingly, the manufactured interdental brush 10 has recesses 8 and 9 having different depths, for example, V, formed on both sides of the handle 3 having a vertically long rectangular cross section so as to intersect with the base end 2 ₁ of the brush wire stem 2. groove becomes opposite shaped slip and pattern shape, mostly in the handle 3 of the opposing part of the result proximal portion proximal end 2 ₁ double dot contact state of the brush wire stem 2 at its bottom of the recess 8 and 8 It is embedded in the wall and is not easily seen through, which makes it look good. Further, the pin hole 7 ₁ is formed in the vertical direction of the base end portion 2 ₁ of the brush wire stem 2, that is, in the state of intersecting with the recesses 8 and 9, and the base end portion 2 ₁ is positioned on the central axis of the handle 3 Is not seen through, that is, the proximal end of the brush wire stem is
Since it is located in the resin portion between the pin hole 7 ₁ and the pin hole 7 ₁ , the base end portion 2 ₁ of the brush wire stem 2 is embedded in the center portion inside the handle, and the linear body is formed by the handle 3 after molding. The base end of is not seen through. Further, the proximal end portion 2 ₁ of the wire stem 2 has a bent portion 2 ₂
It is preferable to form an embedded structure in which the twist wire is unwound and returned from the handle 3.

A plurality of protrusions 6 for positioning the base end portion 2 ₁ of the brush wire stem 2 at the center of the handle forming space 5 of the molding die 4 are provided in a form crossing the base end portion 2 _1. However, at least a pair of projecting bodies 6 arranged in a large number are opposed to each other or one or more projecting bodies 6 are spaced apart from each other. The brush wire stem 2 is supported at the central position in such a manner that the base end portion 2 ₁ of the brush wire stem 2 is sandwiched from both sides, and the other protruding body 6 is formed as a pattern having a low height and is molded in the molding die 4. be only the proximal portion 2 ₁ When press-fitting the resin material into the space 5 abuts against the projecting bodies 6 high inner surface of the mold height of those receiving the pressure, the thickness in the lower projecting bodies 6 height The number of parts is increased so that the rigidity of the handle 3 can be maintained.
In this case, if the projection 6 has a V-shaped cross section, the brush wire stem 2 and the tip of the projection 6 are surely in point contact with each other.

In an example of an interdental brush 10 produced by the manufacturing method according to the present invention, a neck portion 11 is integrally formed at the tip of a handle 3 having a rectangular cross section, and a cylindrical joint portion 12 is formed at the other end, and the tip portion is formed. the proximal end 2 ₁ of the metal wire stem 2 the brush 1 was planted on the peripheral surface, a configuration that is embedded along the axis toward inside handle 3 from the neck portion 11, the tip portion of the brush wire stem 2 neck It becomes the form projected from the tip of 11.

The joint portion 12 has a hollow cylindrical cap 2
0 is removably spliced to use the cap as a grip for extending the handle, and the cap 20 is replaced in the opposite direction so that the brush 1 and the handle 3 are housed in the cap 20 for hygienic storage. Used. The joint portion 12
It is convenient in terms of handling to provide a ring-shaped protrusion 19 for ensuring the fitting of the cap 20 and also serving as a stopper. Further, it is preferable that the handle 3 is provided with a protrusion 18 so as to have a stopper function when the cap 20 is covered so as to ensure the fitting.

A large number of recesses 8 and 9 are arranged in parallel on both side surfaces of the wide handle 3 at intervals. It is desirable that the recesses 8 and 9 have a V-shaped cross section, and the recesses 8 and 9 are not limited to the side-by-side configuration but may be a diagonal knurled configuration or the like. It is a lightening hole 13. With the above-described configuration, the cap 20 is fitted to the joint portion 12, the end portion of the cap 20 is gripped in a style in which the inside of the palm is held, and the neck portion 11 is touched with the finger while the finger is put on the handle 3. By pressing strongly, the protrusion angle of the neck portion 11 can be changed, and the brush 1 can be inserted between the teeth to be cleaned. During this operation, the recesses 8 and 9 also exert a finger slip preventing effect.

FIGS. 3 and 4 show an example of a molding die device for the interdental brush 10 having the above-described structure, which is used for molding the handle 3, the joint portion 12, and the neck portion 11 by the pair of molds 4. The molding space 5 is formed, but the base end portion 2 ₁ of the brush wire stem 2 that has been molded in advance is formed at the axial center from the molding space portion of the neck portion 11 to the molding space portion of the handle 3.
And a gate 14 from which a fluid molding resin material is ejected in the form of opening in the molding space of the joint portion 12 in one molding die 4, and a sleeve for forming a lightening hole. 15 are provided. Then, the mold surface of the molding space portion of the handle 3, a number of projecting bodies 6 having V-shaped cross section in the form of intersecting the base end portion 2 ₁ of the brush wire stem 2 is provided, a recess 8,9 It forms a part to be molded.

As shown in FIG. 5, a protrusion 19 on the joint portion 12 on the handle 3 side is engaged with and spliced with a fitting recess 21 provided on the inner periphery of the opening end of the cap 20 ( Also, when the brush 1 is stored, the protrusion 18 on the handle 3 side is engaged with the fitting recess 21 of the cap 20 to be fixed and used. (Fig. 5b) In this case, it is convenient to provide a hole 22 for draining and deaerating the other end of the cap 20, and if a flange portion 3 ₁ is provided at one end on the handle 3 side, the cap 20 is provided. It becomes a stopper when attaching and detaching 20, and handling is simple.

In the example of FIG. 6, the concave surface portions 16 common to the V-groove-shaped concave portions 8 and 9 formed on the both side surfaces of the handle 3 are molded with a metal mold convex portion (not shown) to improve the appearance quality. The height of the handle 3 is increased, and if necessary, the handle 3 is tapered toward the front neck portion 11 to improve the appearance.

In the example of FIG. 8, the recess 17 formed by the projection 6 has a non-slip function and is used as a means for holding the base end 2 ₁ of the brush wire stem 2 and is formed as a handle. 3 has a pair of penetrating pin holes 7 ₁ formed in the vertical direction. Therefore, even if the resin material is press-fitted from the gate 14 and the base end portion 2 ₁ located in the molding space 5 is press-fitted, Since this base end portion 2 ₁ is inserted into the pin hole 7 ₁ and only abuts against any of the pins (not shown),
Never proximal end 2 ₁ to the outer surface near the handle 3 is located, nor be transparent from the outside.

The present invention also includes the following characteristic configurations. A method for manufacturing an interdental brush, comprising a cylindrical joint portion at a rear end of the handle to which a cap can be joined via a flange portion. A method for manufacturing an interdental brush, wherein friction grips having V-groove-shaped recesses are formed on both sides of the handle in a direction orthogonal to the handle axis. The cap fitted to the rear end of the handle is provided with a ridge protruding in the longitudinal direction on the inner peripheral surface thereof that abuts a side surface parallel to the long axis of the handle, and the handle is connected by connecting the cap. Interdental brush that can be extended. A method for manufacturing an interdental brush, wherein the handle is tapered toward the tip neck portion to gradually reduce the interval and frictional grip portions are formed on both side surfaces.

[0018]

As described above, according to the present invention, at least one of a plurality of projecting bodies provided in the handle molding space of the molding die so as to project in the center direction at a distance from each other is a peripheral side of the brush wire stem. The proximal end of the brush wire stem is held outside the central part of the handle molding space by injection molding the handle so that You can get a product with good appearance without being seen through from the outside, and when you grip the handle with your fingertips and brush it, the flat surfaces on both sides of the handle will fit along your fingertips and you will be able to hold it securely. The directionality of the brush can be changed with certainty without changing the direction of the brush without slipping or rubbing, and it is easy to insert and brush the interdental brush from the front side or back side of the teeth and You can hold it firmly without putting too much force on it, you can firmly maintain the directionality and it is easy to hold and clean the interdental space with a small movement and easily clean the back teeth and the interdental parts of the oral cavity that are difficult to reach. It has a practical effect that it can be greatly improved in handling such as being extremely easy to use. Further, according to the present invention, a plurality of protrusions protruding to the vicinity of the central axis of the handle forming space are provided on the inner surface of the opposing molding die at intervals in the longitudinal direction, and the protrusions protruding in a direction intersecting with the protrusions. Since the body or the contact pin is provided, the mold configuration is simple, the molding cost is low, and the molding operation and the molding time can be greatly shortened.

[Brief description of drawings]

1 shows a product produced according to an example method of the present invention,
(A) is the expanded longitudinal cross-sectional view, (b) is a side view, (c) is a front view.

2 is a sectional front view taken along the line AA in FIG. 1A, and a sectional front view taken along the line BB in FIG.
(C) is a sectional front view taken along the line C-C.

FIG. 3 is a vertical sectional view of the molding die shown in FIG.

FIG. 4 is a vertical sectional view of a molding die according to another embodiment of the present invention.

FIG. 5 shows a state of use of the manufactured product of the present invention,
(A) is a partially cut side view during a brushing operation, and (b) is a partially cut side view when stored.

FIG. 6 shows a product manufactured by a method according to another embodiment of the present invention, (a) is an enlarged vertical sectional view thereof, (b) is a side view thereof,
(C) is a front view.

7 is a sectional front view taken along the line AA in FIG. 6A, and a sectional front view taken along the line BB in FIG.
(C) is a sectional front view taken along line C-C, and (d) is D-D.
It is a cutting | disconnection front view in a line.

FIG. 8 is an enlarged plan view of a product manufactured by a method according to still another embodiment of the present invention, in which (a) is a cut plan view and (b) is a side view.

FIG. 9 is a cut side view of a product manufactured by a conventional manufacturing method.

FIG. 10 is an enlarged vertical sectional view of a part of the manufacturing process of the conventional example.

[Explanation of Codes] 1 Brush 2 Brush Wire Stem 2 ₁ Base End 3 Handle 4 Mold 4 Handle Mold Space 6 Projection 7 Contact Pins 8, 9 Recess 10 Interdental Brush 11 Neck 12 Joint 13 Thickening Hole 20 cap

Front page continuation (72) Inventor Hidemi Nago Hidemi, 2-1-9 Komagata, Taito-ku, Tokyo 401 (72) Inventor, Ryo Yoshikawa 1-3-7 Honjo, Sumida-ku, Tokyo Lion Corporation

Claims (2)

[Claims] 1. A method for manufacturing an interdental brush in which a brush wire stem made of a twisted wire to which a brush is fixed is integrally connected to a handle formed by a molding die by in-molding, and a gap is provided in a handle forming space of the forming die. At least one of a plurality of projecting bodies that are provided so as to project toward the center of the brush wire stem and abut on the peripheral side of the brush wire stem so that the base end portion of the brush wire stem is formed in the handle forming space. A method for manufacturing an interdental brush, which is characterized in that the handle is injection-molded while being held substantially at the center. 2. An interdental brush molding die for molding a handle by in-molding by inserting a proximal end portion of a brush wire stem made of a twisted wire to which a brush is fixed into a handle molding space, wherein A plurality of projecting bodies projecting to the vicinity of the central axis are provided on the inner surface of the opposing molding die at intervals in the longitudinal direction, and projecting bodies or contact pins projecting in a direction intersecting with the projecting bodies are provided. Characteristic interdental brush manufacturing equipment.