JP2012152928A - Method of molding interdental brush and molding device - Google Patents

Abstract

A method for forming an interdental brush capable of inexpensively forming an interdental brush that can substantially completely remove plaque, food residue, etc. without damaging the gums.
An interdental brush includes a main body portion (H) made of a hard material and a brush portion (B) made of a soft material and having a large number of brush hairs. Such an interdental brush is composed of a fixed mold (1), a movable mold (10), and a molding jig (30) provided on the parting side of the movable mold (10). Is formed by a forming apparatus. The molds (1, 10) are provided with a primary molding position (X1) and a secondary molding position (X2), and the molding jig (30) can be rotated 180 ° to move these positions alternately. it can. The main body (H) is formed by primary molding. The main body (H) is placed on the molding jig (30) and moved to the secondary molding position (X2) together with the molding jig (30), and the brush section (B) is moved to the main body (H) by secondary molding. Mold. Primary molding and secondary molding are performed substantially simultaneously.
[Selection] Figure 5

Description

  The present invention relates to an interdental brush molding method and molding apparatus to which an injection molding method is applied. Specifically, the present invention relates to a fixed mold, and a movable mold that is opened and closed with respect to the fixed mold. A molding material provided on the parting side of the movable mold is used to inject a hard material to integrally form a main body portion including a grip portion, a stem portion, and a core portion 1 The present invention relates to an interdental brush molding method and molding apparatus, comprising secondary molding and secondary molding in which a soft material is injected to form a brush portion made of a large number of brush hairs on the outer peripheral portion of the core portion of the main body portion. is there.

  Interdental brushes are known as tools for cleaning dirt such as plaque and food residue between teeth or between teeth and gums. As is well known, a manual interdental brush is composed of a front brush portion in which brush hairs are planted and a rear grip portion. Accordingly, dirt such as plaque can be removed by slowly moving the brush portion between teeth or between teeth and gums. Various such interdental brushes have been proposed. However, the brush disclosed in Japanese Patent Laid-Open No. 9-84632 has a brush portion and a handle portion or a grip portion made of a thermoplastic synthetic resin at the rear portion thereof. It is composed of The brush part is composed of a metal wire stem and brush hair twisted into the tip part. Then, the rear end portion of the wire stem is inserted into the fitting insertion hole of the handle portion and the wire stem is heated by the high frequency induction heating means, or the wire stem is heated by the high frequency induction heating means before insertion, and then the handle portion is The brush portion and the grip portion are integrated with each other by pressing into the insertion hole or pressing the handle so as to contract. This interdental brush has the advantage that it can be manufactured relatively inexpensively because the metal wire stem of the brush part is heated by high-frequency induction heating and fused to the handle part made of thermoplastic synthetic resin. The angle of the metal wire stem can be freely adjusted, and it is also easy to use.

  However, since the bristle is made of nylon and a metal wire stem is applied, the gums may be damaged if used roughly. Therefore, Patent Document 1 proposes an interdental cleaner or toothpick made of a second plastic in which the handle portion is made of the first plastic and the brush portion, that is, the cleaner portion is soft.

JP-T-2001-8506514

  The toothpick shown in Patent Document 1 is composed of an elongated rod-like support made of a first plastic material, and a cleaner portion called an insert or coating covering a part of the surface. The cleaner portion is made of a second plastic material that is softer than the first plastic material. The second plastic material has various shapes such as a rod-shaped material, a plurality of annular or protruding materials. The toothpick is manufactured by injection molding or welding a second plastic material on a support of the first plastic material.

  According to the toothpick described in Patent Document 1, no metal is used for the support and the cleaner part, and the cleaner part is made of a flexible second plastic material, so that the gums are hardly damaged. Benefits are recognized. However, since the cleaner portion is composed of uneven portions such as rods, rings, and protrusions, uniform contact with the teeth cannot be guaranteed. In addition, regarding the molding, each of claims 23 and 24, “23. The second plastic material of the insert or coating (14, 18) is injection-molded on the first plastic material of the support (11). 23. A method for producing an interdental cleaner, in particular a toothpick according to one of claims 1 to 22, characterized in that it is supported by a second plastic material of an insert or coating (14, 18). The process according to claim 23, characterized in that it is welded to the first plastic material of the body (11) ", but no specific injection molding process is disclosed. In the manufacturing method described in Patent Document 1, it is not recognized that a toothpick made of two types of plastic materials can be molded at low cost.

  Therefore, the present invention can form an interdental brush at a low cost that can be contacted evenly even if there are irregularities on the tooth surface or between teeth, and can remove plaque, food residue, etc. almost completely without damaging the gums. It is an object of the present invention to provide a method for forming an interdental brush that can be used, and a forming apparatus used for carrying out the method.

  In order to achieve the above object, the present invention comprises an interdental brush comprising a body portion and a brush portion, and a body portion comprising a grip portion, a stem portion extending from the grip portion, and a core portion at the tip of the stem portion, A brush part made of a hard material such as polypropylene (PP) and a boss part covering the core part in an annular shape and a large number of brush bristles formed on the boss part is soft like a thermoplastic elastomer (TPE). Form from material. The present invention provides such an interdental brush with a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding provided on the parting side of the movable mold. Molding is performed by a molding device including a jig, and in this molding device, primary molding for molding the main body and secondary molding for forming the brush on the core of the main body are performed substantially simultaneously. To do. That is, in the primary molding, the grip part and the stem part of the main body part are moved to the primary molding position of the movable side mold and clamped, thereby clamping the jig on the jig separation surface side of the molding jig. Molded by a cavity formed between the recess and the recess on the parting surface side of the movable mold and the recess on the parting surface side of the fixed mold, and the core is the parting surface side of the movable mold And a cavity formed between the concave portion of the fixed side mold and the concave portion on the parting surface side of the fixed mold. In the secondary molding, the molding jig holding the primary molded body part is moved to the secondary molding position of the movable side mold and clamped, whereby the outer peripheral surface of the core part of the main body part and Molding is performed by a cavity formed between the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold. Such primary molding and secondary molding are performed substantially simultaneously.

That is, in order to achieve the above object, the invention according to claim 1 is a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a party of the movable mold. Primary molding that injects a hard material by using a molding jig provided on the gripping side and integrally molds a main body part consisting of a grip part, a stem part, and a core part, and injects a soft material A method of forming an interdental brush from a secondary molding for molding a brush portion comprising a large number of brush hairs on the outer peripheral portion of the core portion of the main body portion, wherein the gripping of the main body portion is performed in the primary molding. The portion and the stem portion are formed by moving the molding jig to the primary molding position of the movable mold and clamping the mold so that the concave portion on the jig separation surface side of the molding jig and the movable mold A cavity formed between a recess on the parting surface side and a recess on the parting surface side of the fixed mold And the core is formed by a cavity formed between a concave part on the parting surface side of the movable mold and a concave part on the parting surface side of the fixed mold, and the secondary part In molding, the outer peripheral surface of the core part of the main body part is moved by clamping the molding jig holding the primary molded main body part to the secondary molding position of the movable mold. And a cavity formed between the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold, and the first and second moldings are performed substantially simultaneously. Configured.
The invention according to claim 2 is a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding jig provided on the parting side of the movable mold. Primary molding that integrally injects a main body composed of a grip portion, a stem portion, and a core portion by injecting a hard material, and an outer periphery of the core portion of the main body portion by injecting a soft material A method for forming an interdental brush from a secondary molding for forming a brush portion consisting of a large number of brush hairs in the portion, wherein in the primary molding, a part of the grip part of the main body part and a part of the stem part Moves the molding jig to the primary molding position of the movable mold and clamps it so that the concave part on the jig separation surface side of the molding jig and the parting surface side of the movable mold Formed by a cavity formed between the concave portion of the fixed side mold and the concave portion on the parting surface side of the fixed mold, The grip part of the part, the other part of the stem part, and the core part are between the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold. Molding is performed by the cavity formed, and at the time of the secondary molding, the molding jig holding the primary molded body is moved to the secondary molding position of the movable mold and clamped. By forming a cavity formed between the outer peripheral part of the core part of the main body part, the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold, 1st and 2nd shaping | molding is comprised so that it may carry out substantially simultaneously.
According to a third aspect of the present invention, in the molding method according to the first or second aspect, when the mold is moved to the secondary molding position and clamped, the movable side mold and the molding jig hold the mold. The free part of the grip part and the stem part is configured to be held in a holding recess formed on the parting surface side of the movable mold.
According to a fourth aspect of the present invention, in the molding method according to any one of the first to third aspects, a plurality of interdental brushes, each of which has a part of the gripped portion, are substantially arranged for each molding cycle. Are configured to mold simultaneously.

According to a fifth aspect of the present invention, there is provided a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding jig provided on a parting side of the movable mold. A primary molding that integrally molds a main body portion including a grip portion, a stem portion, and a core portion by injecting a hard material, and a soft material that is injected into the core portion of the main body portion. A molding apparatus for molding an interdental brush from a secondary molding for molding a brush portion comprising a large number of brush hairs on an outer periphery, wherein the molding separation surface of the molding jig is the movable side mold. A first position that is flush with the parting surface and a second position that protrudes a predetermined amount from the parting surface, and at the second position, the parting surfaces of the fixed and movable molds Movable to the primary molding position and secondary molding position selected on the side, A jig side recess for molding a part of the grip part and stem part of the main body part is formed on the jig separating surface of the tool, and the primary molding position of the movable side mold is at the position of the main body part. The grip portion and stem recess for forming the grip portion and other portions of the stem portion and the core recess for forming the core portion of the main body are aligned with the jig-side recess. In the secondary molding position, a boss part and a concave part for a brush part for molding a large number of brush hairs are provided in cooperation with the core part of the main body part. On the parting surface side of the next molding position, there are fixed side recesses respectively corresponding to the jig side recesses, the grip part of the movable mold, the stem part recesses, and the core part recesses, and the secondary molding position. Has a holding recess for holding the grip portion and the stem portion held by the forming jig. Together are a recess forming the concave portion and the pair brush portion of the movable die is provided, constructed as a molding apparatus for interdental brushes.
According to a sixth aspect of the present invention, in the molding apparatus according to the fifth aspect, the molding jig is attached to a drive shaft that is provided perpendicular to the parting surface so as to cross the movable mold. And the first and second molding positions of the movable side mold are separated from each other by 180 ° in terms of rotational angle. Is done.
According to a seventh aspect of the present invention, in the molding apparatus according to the fifth or sixth aspect, the molding jig includes a pair of jig members provided symmetrically with respect to the drive shaft. A plurality of side recesses are configured to be provided in a reverse direction in parallel with the jig separation surface.
The invention according to claim 8 is the molding apparatus according to claim 5 or 6, wherein the molding jig is provided symmetrically with respect to the drive shaft. 31 ′), and the first and second jig components include a pair of jig members (32a, 32b, 32′a, 32′b) arranged at predetermined intervals, and the jig A plurality of side recesses are provided in parallel to each jig separation surface (33a, 33b, 33′a, 33′b) in the opposite direction.

  As described above, the present invention provides a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding jig provided on the parting side of the movable mold. Primary molding that integrally injects a main body composed of a grip portion, a stem portion, and a core portion by injecting a hard material, and an outer periphery of the core portion of the main body portion by injecting a soft material It is configured as a method of forming an interdental brush from secondary molding in which a brush portion comprising a large number of brush hairs is molded in the portion. In other words, the interdental brush to be molded is composed of a large number of brush bristles made of a soft material, so that even if there are irregularities between the tooth surfaces or the teeth, the brushes contact evenly and do not damage the gums. In addition, food residues etc. can be removed almost completely. Such a high-quality interdental brush can be easily formed. And this invention is comprised so that it can shape | mold easily by primary shaping | molding and secondary shaping | molding. That is, in the primary molding, the gripping portion and the stem portion of the main body portion move the molding jig to the primary molding position of the movable mold and clamp the mold so that the jig of the molding jig is fixed. Molded by a cavity formed between a recess on the separation surface side, a recess on the parting surface side of the movable mold and a recess on the parting surface side of the fixed mold, and the core is movable Molded by a cavity formed between a concave part on the parting surface side of the side mold and a concave part on the parting surface side of the fixed mold, and in the secondary molding, the primary molded body part is held. By moving the molding jig to the secondary molding position of the movable mold and clamping it, so that the outer peripheral surface of the core part of the main body part and the concave part on the parting surface side of the movable mold And between the concave part on the parting surface side of the fixed mold And it is configured to shape the cavity. Further, these primary and secondary moldings are configured to be performed substantially simultaneously. Therefore, a high-quality interdental brush can be efficiently and continuously formed. This makes it possible to provide an interdental brush at low cost. And according to other invention, since it is comprised so that several interdental brushes which a part of the grip part may continue may be formed substantially simultaneously for every 1 molding cycle, further mass production is possible. This makes it possible to provide an interdental brush at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the interdental brush obtained by embodiment of this invention, The (a) is the stage in the middle of shape | molding at the time of the several interdental brush, The (a) is the shape | molded plurality It is a perspective view which shows each interdental brush. It is a perspective view showing typically a jig concerning an embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the shaping | molding apparatus which concerns on embodiment of this invention, The (a) is typical side sectional drawing, The (a) is the top view of the movable metal mold | die seen from the parting surface of the metal mold, ( (C) is a sectional view taken along line xx in (a). FIG. 5 is an enlarged view showing a main part of the molding apparatus according to the embodiment of the present invention, in which (A) is a portion indicated by an arrow Y in (A) of FIG. 2 is an enlarged perspective view of a portion indicated by an arrow Z in FIG. It is sectional drawing which shows typically the stage in the middle of shape | molding the interdental brush using the shaping | molding apparatus which concerns on embodiment of this invention, The (a) is the state which is performing the primary injection, ( (A) is a sectional view showing a state in which primary molding is completed and a jig is protruded, and (c) is a sectional view showing a state in which primary and secondary molding can be performed.

  The interdental brush according to the present embodiment is roughly composed of a main body portion including a grip portion and the like, and a brush portion formed on the outer peripheral surface of the distal end portion of the main body portion. Hereinafter, an example in which the main body portion is molded from hard polypropylene (PP) and the brush portion is molded from a soft thermoplastic elastomer (TPE) will be described.

  According to the present embodiment, as shown in FIG. 1A, the main body H has a grip portion N, a small-diameter stem portion S extending from the tip of the grip portion N in a rod shape, and a stem. It is integrally molded by primary injection molding from a core portion C that has a tapered diameter reduced from the portion S. Specifically, the grip portion N and the stem portion respectively include first and second portions N1 and N2 and first and second portions S1 and S2. And the brush part B which consists of a several or many brush bristles is shape | molded by secondary injection molding in the outer peripheral part of the core part C, as shown to (A) of FIG. According to the present embodiment, the plurality of interdental brushes are formed by being connected at a part of the grip portions N, N,... And used by the user separately, for example.

  As shown in FIG. 3A, the molding apparatus according to the present embodiment is schematically a fixed mold 1 and a movable side that is opened and closed with respect to the fixed mold 1. It consists of a mold 10 and a molding jig 30 provided on the parting surface P side of the movable mold 10. As will be described in detail later, the forming jig 30 can protrude from the parting surface P of the movable mold 10 by a necessary amount, and in the protruded state, the forming jig 30 can be rotated, for example, 180 ° around its axis. It has become.

  As is well shown in the perspective view of FIG. 2 and the plan view of FIG. 3A, the forming jig 30 has a pair of first and second members having the same shape and structure according to this embodiment. The jig component elements 31 and 31 ′. These jig components 31, 31 'are also composed of a pair of first and second jig members having the same shape and structure. Accordingly, the first jig component 31 will be described below, and the second jig component 31 ′ will be described with the same reference numeral with a dash “′”, and will not be described except for special cases.

  The first jig component 31 includes a pair of first and second jig members 32a and 32b that are long in the lateral direction. Both ends of these jig members 32a and 32b are coupled by coupling members 34 and 34 so as to have a predetermined interval, and have a substantially cross-beam shape when viewed in a plan view. The pair of first and second jig components 31 and 31 ′ configured in this way are coupled with a linear coupling arm 35 at the center thereof in a state of being 180 degrees apart in rotational angle. . A drive shaft 36 is integrally provided at the center of the coupling arm 35. The drive shaft 36 is perpendicular to the pair of first and second jig components 31, 31 ′, and is driven in the axial direction indicated by the arrow A in FIGS. It is also driven in the rotational direction. Therefore, the forming jig 30 composed of the pair of first and second jig components 31 and 31 ′ rotates around the direction and axis with respect to the parting surface P of the movable mold 10. It can be driven in the direction. The drive device that drives the drive shaft 36 as described above is not shown in the figure.

  The first jig member 32a configured as described above has a jig separation surface 33a that is in contact with the parting surface P of the fixed mold 1 during mold clamping. In this embodiment, the jig separation surface 33a is divided into four blocks for convenience, and ten concave portions 40, 40,... Are formed in one block. As shown in the detailed view of FIG. 4A, these concave portions 40 are a first partial molding concave portion 41 of the grip portion N and a second partial molding concave portion of the stem portion S. 42. The first grip portion forming recesses 41, 41,... Are arranged in a row in the lateral direction, and some of them communicate with each other. Further, the tip portion of the first partial molding recess 41 of the grip portion N is narrowed in a mountain shape, and the second partial molding of the stem portion S having a predetermined diameter substantially perpendicular to the side portion from the tip portion. A recess 42 is formed.

  As shown in part in the schematic perspective view of FIG. 2, the jig separation surface 33b of the second jig member 32b also has ten concave portions in one block having the same shape in the reverse direction. 40, 40,... Are formed in four blocks. Further, the jig separation surfaces 33'a and 33'b of the pair of first and second jig members 32'a and 32'b of the second jig component 31 'have the same shape and the same direction. Each of the concave portions 40 ′, 40 ′,... Is formed in four blocks.

  In this way, the ten concave portions 40, 40,... Are set as one block, and the first jig member 32a is provided with four blocks as shown in the plan view of FIG. Four blocks are also provided on the second jig member 32b. Therefore, the first jig component 31 is provided with 8 blocks, and the second jig component 31 'is also provided with 8 blocks, so that 16 blocks are provided as a whole. According to the present embodiment, the interdental brush is formed by primary and secondary molding, so that eight blocks, that is, 80 interdental brushes are molded per cycle as will be described in detail later.

  The molding jig 30 configured as described above is formed on the movable side mold 10 because the first and second jig components 31 and 31 'are symmetrical with the drive shaft 36 as the center of symmetry. Fitting grooves 12 a, 12 b, 12 ′ a, 12 ′ b, 13 into which the forming jig 30 can be fitted are formed at positions equidistant from the formed through holes 11. These fitting grooves are opened on the parting surface P side. The first and second jig members 32a and 32b are fitted in the fitting grooves 12a and 12b, respectively, and the second jig members 32'a and 32 are fitted in the fitting grooves 12'a and 12'b. 'b is fitted, and the coupling arm 35 is fitted in the fitting groove 13 respectively. The fitting grooves for the coupling members 34 to 34 'are not shown. The depths of these fitting grooves 12a, 12b, 12′a, 12′b, 13 are determined so that the above-described components 32a to 32′b of the forming jig 30 are separated from each other when the above-described components 32a to 32′b are fitted into these grooves. The surfaces 33 a to 33 ′ b are deep enough to be flush with the parting surface P of the movable mold 10.

  As described above, the pair of first and second jig components 31, 31 ′ have the same size, the same structure, and are 180 ° apart from each other, so that the fitting grooves 12a, 12b and The fitting grooves 12′a and 12′b are also separated by 180 °. Thus, the recessed part from which a shape differs is formed in the 1st, 2nd position of the parting surface P of the movable side metal mold | die 10 spaced apart, ie, 1st and 2nd shaping | molding position X1, X2. That is, a recess for forming the other part of the main body H is formed at the primary molding position, and a recess for forming the brush part B is formed at the secondary molding position. This will be described in more detail below. A part of the parting surface P outside the fitting grooves 12a and 12b at the primary molding position X1 indicated by X1 in FIG. 3A is partially shown in FIG. As shown schematically in FIG. 4A, the second partial molding recesses 15, 15,... Of the stem S are aligned with the core molding recesses 16, 16,. Is formed. The second partial molding concave portions 15, 15,... Of the stem portion S are aligned with the first partial molding concave portions 42, 42,. In addition, the second partial molding recesses 17, 17,... Of the grip portion N are formed in the parting surface P inside the fitting grooves 12a, 12b at the primary molding position X1. The second partial molding recesses 17, 17,... Of the grip portion N are aligned with the first partial molding recesses 41, 41,... Of the grip portion N of the molding jig 30.

  A part of the parting surface P outside the fitting grooves 12′a and 12′b at the secondary molding position X2 of the movable mold 10 is shown in FIG. As shown in FIG. 4A, the half-shaped holding concave portions 15 ′, 15 ′,... In which the second portion S2 of the stem portion S that has been primarily molded is held tightly. The half-shaped concave portions 19, 19,... Are formed in the same manner as the core portion C enters. The concave portion 19 has a tapered shape and a thin tip, but there is a predetermined interval between the core portion C to be inserted and the inner peripheral wall of the concave portion 19. The boss part b made of is formed. A plurality or a plurality of concave portions 20, 20,... For forming bristle are formed in communication or opening with the inner peripheral wall of the concave portion 19 as described above. The brush bristle forming recesses 20 have a tapered tip and are formed in a large number on the parting surface P of the movable mold 10 and also in a direction perpendicular to the parting surface P. . Since the concave portions 20, 20,... Are formed in such a tapered structure and position, the interdental brush having the brush portion B can be easily taken out from the molds 1, 10 after the secondary molding.

  Further, the half part in which the second portion N2 of the grip portion N is fitted or held on the parting surface P inside the fitting grooves 12′a and 12′b at the secondary molding position X2 during the secondary molding. Are formed in the shape of concave holding portions 17 ′, 17 ′,. These holding recesses 17 ′, 17 ′,... Are aligned with the first partial molding recesses 41, 41,. The holding recesses 15 ′ and 17 ′ formed in the movable mold 10 are larger than the molding recesses 15 and 17 so that the primary molded body H can be easily fitted.

  On the parting surface P of the movable side mold 10, as described above, the second partial molding recess 15 of the stem S, the core molding recess 16, the half-shaped holding recess 15 ', A half-shaped concave portion 17 ′ or the like is formed, and the gripping surfaces 33 a to 33 ′ b of the first and second jig members 32 a to 32 ′ b of the forming jig 30 are gripped as described above. The first partial molding recess 41 of the part N and the first partial molding recess 42 of the stem S are formed, but on the parting surface side of the fixed mold 1 at the primary molding position X1. Also, a concave portion is formed that is paired with the above-described molding concave portions 41, 42, 15, 16, 19, and the like. Further, on the parting surface side of the fixed mold 1 at the secondary molding position X2, a concave portion that holds the stem portion S of the main body portion H, a part of the grip portion N and the like while being pressed during the secondary molding, A recess for forming the bristle is formed. However, the structure or shape thereof is not shown in the drawings and is not particularly described because it is easily understood by those skilled in the art.

  As shown in FIG. 3A, the fixed-side mold 1 configured as described above includes first and second sprues 2 and 3 that cross the fixed-side mold 1. The first sprue 2 is branched into a plurality of sprues and runners and is opened in the second partial molding recesses 17, 17,... Similarly, the second sprue 3 branches into a plurality of sprues and runners, and is opened to the half-shaped recesses 19, 19,... Via the respective gates. Although not shown in FIG. 3A, polypropylene (PP) is injected from the first sprue 2 and thermoplastic elastomer (TPE) is injected from the second sprue 3. .

  Next, an example of forming an interdental brush using the above forming apparatus will be described with reference to FIG. The drive shaft 36 is driven or pulled to fit the forming jig 30 into the fitting grooves 12a, 12b, 12'a, 12'b, 13 of the movable mold 10. Then, the movable mold 10 is clamped with respect to the fixed mold 1. The clamped state is shown in FIG. When the mold is clamped, the first partial molding concave portions 41, 41,... Of the grip portion N of the pair of first and second jig members 32a, 32b and the first partial molding concave portion 42 of the stem portion S, Of the grip part N of the movable side mold 10, the second partial molding recesses 17, 17,..., The stem part S of the second partial molding recesses 15, 15,. A molding cavity of the main body H is constituted by the molding recesses 16, 16,. At this time, the cavity is configured to cooperate with a recess formed on the parting P surface side of the fixed mold 1 as described above.

  The first injection machine J1 plasticizes the polypropylene as is conventionally known, and fills the cavity through the sprues and gates branched from the first sprue 2. By this primary molding, as shown by a large number of dots in FIG. 5A, 80 main body parts H including the grip part N, the stem part S, and the core part C are formed.

  Open the movable mold 10. Then, due to the difference between the shape and size of the concave portion of the forming jig 30 and those of the fixed side mold 1, the main body portion H remains on the forming jig 30 and is opened. The drive shaft 36 is driven in the direction of arrow A2, and the forming jig 30 is protruded. The protruding state is shown in FIG. The forming jig 30 is in a rotatable state while holding the main body portions H, H,.

  The forming jig 30 at the primary forming position X1 is rotated by 180 °. Then, the first and second jig members 32a and 32b of the molding jig 30 holding the main body portions H, H,... Are in the second molding position X2 and the first of the unfilled molding jig 30. The first and second jig members 32′a and 32′b reach the first molding position X1. The drive shaft 36 is retracted. Then, the first and second jig members 32 a and 32 b of the forming jig 30 holding the main body portions H, H,... Fit into the fitting grooves 12 ′ a and 12 ′ b of the movable mold 10. At this time, the second portion N2 of the grip portion N that has been primarily molded is tightly held in the half-shaped holding concave portion 17 ′ of the movable mold 10, and the second portion S2 of the stem portion S is half Similarly, it is held densely in the split holding recess 15 '. The core C is held in the half-shaped recess 19 with a gap.

  The movable mold 10 is clamped with respect to the fixed mold 1. Then, at the primary molding position X1, the concave portions of the first and second jig members 32′a and 32′b, the concave portion of the movable die 10 and the concave portion of the fixed die 1 are shown in FIG. As described above, a cavity for primary forming the main body H is configured. At the secondary molding position X2, the outer peripheral surface of the core part C, the concave part 19 for forming the boss part b, and the concave parts 20, 20,... For forming the bristle are integrated with the boss part b around the core part C. A cavity for forming the bristle to be formed is formed. A plasticized thermoplastic elastomer (TPE) is injected from the second injection machine J2. The interdental brush which consists of the main-body part H and the brush part B is shape | molded by this secondary shaping | molding. At substantially the same time, polypropylene (PP) is injected from the first injection machine into the cavity at the primary molding position X1. Waiting for cooling and solidification, the movable mold 10 is opened. At the secondary molding position X2, as described above, 80 interdental brushes are ejected by an ejector device (not shown). At the primary molding position X1, the main body H is held in the recesses of the first and second jig members 32'a and 32'b. In the following, the first and second moldings are performed substantially simultaneously as described above.

  This embodiment can be variously modified. For example, the number of moldings per cycle is not limited to the above embodiment. Further, in the primary molding, the grip portion N and the stem portion S of the main body H are formed by the concave portions formed across the forming jig 30 and the movable side mold 10, but everything except the core portion C is formed. It can also be formed by the forming jig 30. Then, the movable mold 10 structure at the primary molding position X1 is simplified. Further, the pair of jig components 31 and 31 ′ of the forming jig 30 is composed of first and second jig members 32a, 32b, 32′a and 32′b. It can also be implemented with the tool members 32a, 32'a. In addition, according to the present embodiment, the pair of jig components 31, 31 'are angularly separated from each other by 180 °, so that the balance is improved, but it is not necessary to be limited to 180 °.

H body part N grip part N1 first part of grip part N2 second part of grip part C core part S stem part S1 first part of stem part S2 second part of stem part B brush part b boss part DESCRIPTION OF SYMBOLS 1 Fixed side metal mold | die 10 Movable side metal mold 11 Through-hole 12a, 12b Fitting groove 15 Recessed part 15 'for stem part 2nd partial shaping | molding 16 Recessed part 16 for core part shaping | molding Concave part 2nd of a grip part Concave part 17 'for holding part 19 Concave part 19 Concave part 30 Forming jigs 31, 31' First and second jig constituent elements 32a, 32b First and second jig members 33a Jig separation surface 34 Coupling member 35 Coupling Arm 36 Drive shaft 40 Concave part 41 Concave part for first partial molding of grip part Concave part for first partial molding of stem part X1 Primary molding position X2 Secondary molding position

Claims (8)

Using a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding jig provided on the parting side of the movable mold, Primary molding that integrally molds the main body part composed of the grip part, the stem part, and the core part, and a brush made of a large number of brush hairs on the outer peripheral part of the core part of the main body part by injecting the soft material A method for forming an interdental brush from secondary molding for molding a part,
In the primary molding, the grip part and the stem part of the main body part are separated from the jig of the molding jig by moving the molding jig to the primary molding position of the movable mold and clamping the mold. A cavity formed between a recess on the surface side, a recess on the parting surface side of the movable mold and a recess on the parting surface side of the fixed mold, and the core is formed on the movable side Molded by a cavity formed between a recess on the parting surface side of the mold and a recess on the parting surface side of the fixed mold,
In the secondary molding, by moving the molding jig holding the primary molded body part to the secondary molding position of the movable side mold and clamping it, the core part of the body part Molded by a cavity configured between the outer peripheral surface of the movable part and the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold,
A method for forming an interdental brush, wherein the primary and secondary molding are performed substantially simultaneously. Using a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding jig provided on the parting side of the movable mold, Primary molding that integrally molds the main body part composed of the grip part, the stem part, and the core part, and a brush made of a large number of brush hairs on the outer peripheral part of the core part of the main body part by injecting the soft material A method for forming an interdental brush from secondary molding for molding a part,
In the primary molding, a part of the grip part of the main body part and a part of the stem part are moved by clamping the mold by moving the molding jig to the primary molding position of the movable side mold. The main body is molded by a cavity formed between a recess on the jig separation surface side of the jig, a recess on the parting surface side of the movable mold, and a recess on the parting surface side of the fixed mold. The grip part of the part, the other part of the stem part, and the core part are between the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold. Molded by the configured cavity,
At the time of the secondary molding, the core of the main body portion is clamped by moving the molding jig holding the primary molded main body portion to the secondary molding position of the movable side mold and clamping the mold. Molded by a cavity configured between the outer peripheral part of the part, the concave part on the parting surface side of the movable mold and the concave part on the parting surface side of the fixed mold,
A method for forming an interdental brush, wherein the primary and secondary molding are performed substantially simultaneously.   3. The molding method according to claim 1, wherein when the mold is moved to the secondary molding position and clamped, the grip portion and the stem portion held by the movable mold and the molding jig are free. A method for forming an interdental brush, in which a portion being held is held in a holding recess formed on the parting surface side of the movable mold.   The interdental brush which shape | molds the several interdental brush in which a part of grip part continues in every shaping | molding cycle in the shaping | molding method in any one of Claims 1-3 substantially simultaneously. Molding method. Using a fixed mold, a movable mold that is opened and closed with respect to the fixed mold, and a molding jig provided on the parting side of the movable mold, Primary molding that integrally molds the main body part composed of the grip part, the stem part, and the core part, and a brush made of a large number of brush hairs on the outer peripheral part of the core part of the main body part by injecting the soft material A molding device for molding an interdental brush from secondary molding for molding a part,
The forming jig takes a first position where the jig separating surface is flush with the parting surface of the movable mold, and a second position protruding a predetermined amount from the parting surface, and In the second position, it is possible to move to the primary molding position and the secondary molding position selected on the parting surface side of the fixed side and movable side molds. A jig side recess for forming a part of the grip portion and stem portion of the main body portion is formed,
In the primary molding position of the movable mold, the grip part for molding the grip part of the main body part and the other part of the stem part, the concave part for the stem part, and the core part of the main body part are formed. The core recess is aligned with the jig side recess, and a boss and a large number of brush hairs are formed at the secondary molding position in cooperation with the core of the main body. A recess for the brush part is provided,
On the parting surface side of the primary molding position of the fixed side mold, fixed side recesses respectively corresponding to the jig side recess, the grip part of the movable side mold, the stem part recess, and the core part recess However, at the secondary molding position, a gripping portion held by the molding jig and a holding concave portion for holding the stem portion are provided, and a pair with a concave portion for the brush portion of the movable side mold is provided. A device for forming an interdental brush provided with a concave portion to be formed.   6. The molding apparatus according to claim 5, wherein the molding jig is attached to a drive shaft provided perpendicular to the parting surface so as to cross the movable mold, and is rotated or rotated by the drive shaft. A device for forming an interdental brush, which is configured to be rotated in a swinging manner, and wherein the first and second molding positions of the movable mold are separated from each other by 180 ° in terms of rotation angle.   The molding apparatus according to claim 5 or 6, wherein the molding jig includes a pair of jig members (32a, 32'a) provided symmetrically with respect to the drive shaft, and the jig side recess. Is a device for forming an interdental brush, which is provided in parallel with a plurality of jig separating surfaces (33a, 33′a) in opposite directions.   The molding apparatus according to claim 5 or 6, wherein the molding jig is composed of first and second jig components (31, 31 ') provided symmetrically with respect to the drive shaft, The first and second jig components are composed of a pair of jig members (32a, 32b, 32′a, 32′b) arranged at predetermined intervals, and the jig-side recesses are separated from each other. A device for forming an interdental brush, which is provided in parallel on the surfaces (33a, 33b, 33′a, 33′b) in reverse directions.

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