JPH08142114A - Three-dimensional hollow molded product and coat-molding method thereof - Google Patents

Abstract

PURPOSE: To provide a three-dimensional hollow molded product, and coat- molding method which can prevent the deformation and breakdown of the bonding part for an injection molding core and can prevent the leaking of fused resin into a hollow part through the gap of the bonded part of the injection molding core when a coat-molding is being carried out. CONSTITUTION: A three-dimensional hollow molded product is formed by bonding members made of resin 10 and 11, which are molded in at least two divided shapes beforehand. This three-dimensional hollow molded product comprises an injection molding core having a hollow part 21 and a coating member 30 made of resin for coating at least a part of the outer surface of the injection molding core. The continuous protruding part is formed on the bonding surface of one member 10 made of resin. A continuous recess part, which is coupled with the protruding part, is formed on the bonding surface of the other member 11 made of resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional hollow molded article having a complicated shape such as a spherical shape, a box shape, a bent tubular shape or a branched tubular shape and having a hollow portion, and a coating molding method thereof.

[0002]

2. Description of the Related Art One of the methods for producing a three-dimensional hollow molded article by injection molding using a thermoplastic resin is a coating molding method (also called a two-shell method). In this coating molding method, first, a resin member preliminarily molded into a shape of at least two parts is prepared. Then, these resin members are joined together to form an injection molding core having a hollow portion. Next, after this injection molding core is mounted in the cavity of the mold, molten resin is injected into the space formed by the mold surface of the injection molding core and the cavity. Thus, a three-dimensional hollow molded article is molded by coating at least a part of the outer surface of the injection molding core with the resin.

By using such a coating molding method for a three-dimensional hollow molded article, a synthetic resin having a complicated three-dimensional shape and a hollow portion, which cannot be molded at all by an ordinary injection molding method. A three-dimensional hollow molded product can be molded. In addition, this coating molding method can reduce the number of parts by integrating with other parts, the inner surface of the hollow part is smooth, the dimensional accuracy of the molded product is good, and the manufacturing equipment cost is low. It has various advantages such as being inexpensive. Such a coating molding method has been widely adopted as a molding method for various parts having a hollow portion in addition to parts in the automobile field such as an air intake manifold and an air duct, a pipe for liquid such as water.

A method for coating and molding a three-dimensional hollow molded article is disclosed in, for example, Japanese Patent Laid-Open No. 59-198116 and Japanese Patent Laid-Open No. 3-23.
9516, JP-A-63-237918, JP-A-5-305679, JP-A-62-21811.
It is known from JP-A-7.

[0005]

Problems to be Solved by the Invention JP-A-59-1981
In the technology disclosed in Japanese Patent Laid-Open No. 16-35, and Japanese Patent Laid-Open No. 3-239516, the bonding surface of the resin member is flat. Therefore, for example, when an adhesive is applied to the joint surface to join the two resin members, the adhesive force on the joint surface of the resin member is low, and the rigidity of the obtained injection molding core is low. In addition, at the time of coating molding, the pressure applied to the injection molding core having the hollow portion due to the resin injection pressure causes the joining portion between the resin member and the resin member (hereinafter, the joining portion of the injection molding core There is a problem that it will be deformed or damaged. Further, there is a problem that the molten resin leaks into the hollow portion through the gap of the joining portion of the injection molding core.

In the technique disclosed in Japanese Patent Laid-Open No. 63-237918, resin members are welded to each other by hot plate welding. In addition, in the technique disclosed in Japanese Patent Laid-Open No. 5-305679, resin members are welded to each other by hot plate welding, vibration welding, ultrasonic welding, or the like. However, when such a welding method is adopted, there are problems that the number of manufacturing steps of the injection molding core is increased and that equipment for welding is required. Further, if the resin members are not completely welded to each other, there is a problem that the molten resin leaks into the hollow portion from the gap of the joint portion of the injection molding core.

In the technique disclosed in Japanese Unexamined Patent Publication No. Sho 62-218117, as shown in FIG. 2D of this publication, when a resin member is molded, an undercut fitting portion J is made of resin. It is integrally molded at a proper place on the joint surface of the members. It is said that by providing such a fitting portion J, the injection molding core can be mounted in the cavity of the mold after fitting the resin member, and the working efficiency can be improved. However, the fitting portion J is not continuously provided on the joint surface. Further, the purpose of providing the fitting portion J is to improve work efficiency. That is, at the time of coating molding, the problem that the joint portion of the injection molding core is deformed or damaged due to the pressure applied to the injection molding core having the hollow portion due to the flow of the resin, or the molten resin The fitting portion J is not provided in order to solve the problem that the oil leaks into the hollow portion from the gap of the joining portion of the injection molding core.

[0008] Therefore, an object of the present invention is to form a coating during
It is possible to prevent the joint portion of the injection molding core from being deformed or damaged by the pressure applied to the injection molding core having the hollow portion due to the resin injection pressure. It is an object of the present invention to provide a three-dimensional hollow molded article capable of preventing the child from leaking into the hollow portion from the gap of the joint portion, and a coating molding method thereof.

[0009]

The three-dimensional hollow molded article of the present invention for achieving the above object is (a) at least 2
An injection molding core having a hollow portion, which is formed by joining preformed resin members in a divided state, and (b)
A three-dimensional hollow molded article comprising a resin-made covering member that covers at least a part of the outer surface of the injection molding core,
A continuous convex portion is formed on the joint surface of the one resin member, and a continuous concave portion that fits the convex portion is formed on the joint surface of the other resin member. And

In the three-dimensional hollow molded article of the present invention, as shown in FIGS. 1B and 2B, the continuous protrusions formed on the joint surface of the one resin member are It is composed of two planes, and the angle θ at which the two planes intersect
₁ (degree) is 0 <θ ₁ <180, and two continuous recesses formed on the joint surface of the other resin member are also composed of planes, and the angle θ ₂ ( It is desirable that (degree) is θ ₂ = 360−θ ₁ . Note that θ ₂ and θ ₁ do not have to satisfy the above relational expression exactly, and when θ ₂ is in the range of (360−θ ₁ ) ± 20 (degrees), θ ₂ = 360−θ ₁ Are satisfied. The same applies to the following.

In this case, as shown in FIG. 9B, a continuous groove is formed in the region of the recess where two planes forming the continuous recess intersect with each other. It is preferable in that it can be surely prevented from leaking into the hollow portion from the gap of the joint portion of the core. The width (w) of the groove is the width of the joint surface (the thickness of the resin member portion near the joint surface) t
, T / 20 ≦ w ≦ t / 2, and more preferably t
/ 10 ≦ w ≦ t / 3, more preferably t / 5 ≦ w ≦ t /
3 is desirable. The depth (d) of the groove is t
/ 20 ≦ d ≦ t / 2, more preferably t / 10 ≦ d ≦ t
/ 3, and more preferably t / 5 ≦ d ≦ t / 3.

Alternatively, in the three-dimensional hollow molded article of the present invention, as shown in FIG. 9C, the continuous protrusions and recesses formed on the joint surface of the resin member are curved surfaces. Is desirable. The radius of curvature (r) of the curved surface is t /
It is desirable that 2 ≦ r ≦ 3t, more preferably t / 2 ≦ r ≦ 2t, and even more preferably 3t / 4 ≦ r ≦ 2t.

In the three-dimensional hollow molded article of the present invention, in order to reliably prevent the joint portion of the injection molding core from being deformed or damaged by the pressure applied to the injection molding core having the hollow portion. In addition, as shown in FIG. 9D, it is preferable to thicken the portion of the resin member near the joint surface. In this case, when the thickness of the portion of the resin member away from the joint surface is T and the thickness of the portion of the resin member near the joint surface (width of the joint surface) is t, 1.1T ≦ t ≦ 3
T, and more preferably 1.1T ≦ t ≦ 2.5T. When the cross-sectional shape of the resin member is annular, when the inner diameter of the annular cross section is r ₀ and the width of the thickened resin member portion near the joint surface is W, (π / 1
2) It is desirable that r ₀ ≦ W ≦ (π / 3) r ₀ .
When the cross-sectional shape of the resin member is an annular polygon, the radius of the inscribed circle of the inner polygon may be r ₀ .

The means for joining the resin members may be a method for joining the resin members using an adhesive, or a method for welding the resin members by hot plate welding, vibration welding, ultrasonic welding or the like. As shown in FIG. 6, it is desirable to form a snap fit for joining the resin member on the outer surface of the resin member near the joining surface from the viewpoint of simplifying the joining method.

Alternatively, as shown in FIG. 7, the three-dimensional hollow molded article further includes a connecting member as a joining means for joining the resin members, and an uneven portion is formed on the outer surface of the injection molding core. , The inner surface of the connecting member is formed with an uneven portion that fits with the uneven portion formed on the outer surface of the injection molding core, and the uneven portion formed on the inner surface of the connecting member and the injection molding It is also desirable to join the resin members by fitting the concave and convex portions formed on the outer surface of the core.

When the portion of the injection molding core having the uneven portion formed on the outer surface has a cylindrical shape and the connecting member has a hollow cylindrical shape, the outer surface of the injection molding core and the connecting member are connected. It is preferable that the uneven portion formed on the inner surface of the member has a spiral shape.

Alternatively, as shown in FIG. 8, melt-spun fibers, glass fibers, as means for joining resin members,
The three-dimensional hollow molded article further includes at least one material selected from the group consisting of carbon fiber and film,
It is desirable that the resin member be joined by winding this material around the outer surface of the injection molding core.

The method of coating and molding a three-dimensional hollow molded article according to the present invention to achieve the above object is (a) a resin member preformed in a shape of at least two parts, A continuous convex portion is formed on the joint surface of the resin member, and a resin member having a continuous concave portion that fits the convex portion is formed on the joint surface of the other resin member. The step of forming an injection molding core having a hollow portion, and (b) mounting the injection molding core in the cavity of the mold, and then forming the injection molding core and the mold surface of the cavity. A step of injecting a molten resin into the space formed by the above, thereby coating at least a part of the outer surface of the injection molding core with the resin.

In the three-dimensional hollow molded article coating method according to the present invention, the continuous convex portion formed on the joint surface of the one resin member is composed of two planes. The intersecting angle θ ₁ (degrees) is 0 <θ ₁ <180, and two continuous recesses formed on the joint surface of the other resin member are also formed by planes, and the angle at which the two planes intersect. It is preferable that θ ₂ (degree) is θ ₂ = 360−θ ₁ . In this case, a continuous groove is formed in the region of the recess where two flat surfaces that form the continuous recess intersect, so that the molten resin leaks into the hollow portion from the gap of the joint portion of the injection molding core. Is preferable because it can be reliably prevented.

Alternatively, in the coating molding method for a three-dimensional hollow molded article according to the present invention, it is desirable that the continuous convex portions and concave portions formed on the joint surface of the resin member are curved surfaces.

In the method for coating and molding a three-dimensional hollow molded article of the present invention, the pressure applied to the injection molding core having the hollow portion due to the injection resin pressure during coating molding causes the injection molding core In order to reliably prevent the joint portion from being deformed or damaged, it is preferable to thicken the portion of the resin member near the joint surface.

In the method of coating and molding a three-dimensional hollow molded article of the present invention, the method of joining resin members includes a method of joining resin members using an adhesive, hot plate welding, vibration welding, ultrasonic welding, etc. Although it is possible to use a method of welding a resin member by means of a simple method, it is possible to form a snap fit on the outer surface of the resin member in the vicinity of the joint surface and then join the resin member by this snap fit. It is desirable from the viewpoint of

Alternatively, as a method of joining resin members, an uneven portion is formed on the outer surface of the injection molding core,
An uneven surface formed on the outer surface of the injection molding core and an inner surface of the connection member using a connecting member having an uneven surface formed on the inner surface for fitting with the uneven surface formed on the outer surface of the injection molding core. It is preferable to join the resin member by fitting the concave-convex portion formed in 1.

When the portion of the injection molding core having the uneven surface formed on the outer surface has a cylindrical shape and the connecting member has a hollow cylindrical shape, the outer surface of the injection molding core and the connecting member are The uneven portion formed on the inner surface is preferably spiral.

Alternatively, as a method for joining the resin members, at least one material selected from the group consisting of melt-spun fibers, glass fibers, carbon fibers and films is wound around the outer surface of the injection molding core. ,
It is preferable to join resin members.

The resin material constituting the resin member may be appropriately selected according to the required chemical resistance, heat resistance, impact resistance, transparency and the like. For example, nylon 6 and nylon 6
6, polycarbonate, polyacetal, modified polyphenylene ether, and polybutylene terephthalate can be exemplified. If necessary, an additive such as a dye or a pigment, or a filler or a reinforcing material may be added to the resin material. As a filler or a reinforcing material, silica, diatomaceous earth, alumina, titanium oxide, magnesium oxide, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium sulfate, potassium titanate, barium sulfate, Examples of calcium sulfite, talc, clay, mica, glass fiber, carbon fiber, glass flake, glass beads, calcium silicate, montmorillonite, bentonite, aluminum powder, molybdenum sulfide, boron fiber, silicon carbide fiber, polyester fiber, polyamide fiber. You can

The resin member may be manufactured by any known manufacturing method, for example, an injection molding method, an extrusion molding method, a compression molding method and the like can be mentioned as a preferable manufacturing method.

The resin covering member is preferably made of a resin material having a melting point higher than that of the resin material forming the resin member. Such a resin material may be appropriately selected from various resin materials based on the resin material forming the resin member, and may be the same material as the resin material forming the resin member or a different material. May be. When different materials are used, it is necessary to consider the mutual compatibility and weldability of these resin materials. For example, when nylon 6 is selected as the resin material forming the resin member, as the resin material forming the resin covering member, in addition to nylon 66, nylon 46, and the like, metaxylylenediamide and adipic acid are condensed. The obtained polyamide or the like can be used. When nylon 66 is selected as the resin material forming the resin member, nylon 46 or the like can be used as the resin material forming the resin covering member. Furthermore, when polybutylene terephthalate is selected as the resin material forming the resin member, polyethylene terephthalate or the like can be used as the resin material forming the resin covering member. The resin material forming the resin-made covering member may be added with an additive such as a dye or a pigment, or a filler or a reinforcing material, if necessary, as in the case of the resin material forming the resin-made member. Good.

The resin member may be preliminarily molded into a shape not only divided into two but also divided into three or more.

Examples of melt-spun fibers as a means for joining resin members include nylon fibers, polyester fibers, and acrylic fibers. Further, a nylon film can be exemplified as a film as a joining means of resin members.

The three-dimensional hollow molded article of the present invention has a complicated shape such as a spherical shape, a box shape, a bent tubular shape or a branched tubular shape, and has a hollow portion. Specifically, various boxes and containers, components in the automobile field such as an intake manifold and an air duct that serve as a flow path when supplying an air-fuel mixture to an engine of an automobile, pipes for liquid such as water, etc. may be exemplified. it can.

[0032]

In the present invention, a continuous convex portion is formed on the joint surface of one resin member, and a continuous concave portion that fits with the convex portion is formed on the joint surface of the other resin member. Has been formed. When at least a part of the outer surface of the injection molding core is coated with resin, if pressure is applied from the outside of the joint portion of the injection molding core due to the flow of the resin, the joint portion of the injection molding core is compressed. . Then, the convex portion formed on the joint surface of one resin member and the concave portion formed on the joint surface of the other resin member surely mesh with each other, and the gap between the joint surfaces is closed. Moreover, since these convex portions and concave portions are formed continuously, it is possible to reliably prevent the molten resin from leaking out into the hollow portion from the gap of the joint portion of the injection molding core.

When pressure is applied from the outside of the joint portion of the injection molding core during coating molding, the joint portion of the injection molding core is compressed. Then, the convex portion formed on the joint surface of one resin member and the concave portion formed on the joint surface of the other resin member surely mesh with each other. Moreover, these protrusions and recesses are formed continuously. Therefore, the pressure applied to the injection molding core is dispersed at the joining portion of the injection molding core. Further, the joint surface of the resin member will not be displaced by the applied pressure. As a result, it is possible to reliably prevent the joint portion of the injection molding core from being deformed or damaged by the pressure applied to the injection molding core having the hollow portion due to the resin injection pressure during the covering molding.

Furthermore, by providing a convex portion and a concave portion on the joint surface and employing the above-mentioned joining means or joining method, the resin members can be joined easily and surely. There is an advantage that the production process of the three-dimensional hollow molded product can be simplified and the productivity can be improved.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments with reference to the drawings, but the present invention is not limited to these embodiments.

Example 1 The three-dimensional hollow molded article of Example 1 is an air duct. FIG. 1A shows a schematic perspective view of one of the resin members 10 that is pre-molded into a shape in which the resin is divided into two parts. FIG. 1B shows the same as FIG.
Figure 1B shows a schematic end view along line 1B-1B. Also,
A schematic perspective view of the other 11 of the resin member is shown in FIG.
2B-2 in FIG. 2B, the line 2B-2 in FIG.
A schematic end view along B is shown.

In the first embodiment, as shown in FIG.
The continuous convex portion formed on the joint surface 12 of one resin member 10 is composed of two planes, and the angle θ ₁ (degree) at which the two planes intersect is 120 degrees. On the other hand, as shown in FIG. 2, two continuous recesses formed on the joint surface 13 of the other resin member 11 are also formed by planes,
The angle θ ₂ (degrees) where the _two planes intersect is 240 degrees.

FIG. 3A shows a schematic perspective view of the three-dimensional hollow molded article of Example 1. A schematic end view taken along line 3B-3B in FIG. 3A is shown in FIG. This three-dimensional hollow molded article is formed by joining resin members 10 and 11 and has a hollow portion 21 for injection molding.
And a resin covering member 30 for covering at least a part of the outer surface of the injection molding core 20.

The three-dimensional hollow molded article of Example 1 is composed of a "U" -shaped portion 31 and a linear portion 32 extending from the bottom of the U-shaped portion 31. The U-shaped portion 31 and the straight portion 32 are provided with a hollow portion communicating with each other.
A fluid flows through this hollow portion. An opening 21A is formed in the hollow portion 21 formed in the injection molding core 20.
This opening 21A is a U-shaped portion 3 of the three-dimensional hollow molded product.
It is located at both ends of 1 and one end of the linear portion 32.
A flange portion 33 is formed integrally with the resin coating member 30 at the portion of the resin coating member 30 outside the opening 21.

The coating molding method for producing the three-dimensional hollow molded article of Example 1 will be described below.

First, resin molding members 10 and 11 which have been molded in advance into the shape of the two-divided state shown in FIGS. 1 and 2 are joined to form an injection molding core 20 having a hollow portion. The joining of the resin members was performed using an adhesive in Example 1. In this way, the injection molding core 20 whose schematic perspective view is shown in FIG. A schematic end view taken along the line 4B-4B in FIG. 4A is shown in FIG. The resin members 10 and 11 were made of nylon 6 containing glass fiber and had a thickness of 2.0 mm.

Next, as shown in the schematic partial cross-sectional view of FIG. 5A, the injection molding core 20 is mounted in the cavity 41 of the mold 40. For example, a metal rod 42 extending toward the inside of the cavity 41 is provided in the mold 40,
The hollow portion 21 of the injection molding core 20 is attached to the metal rod 42.
The injection molding core 20 can be mounted in the cavity of the mold by inserting the opening 21A.

Thereafter, as shown in the schematic partial cross-sectional view of FIG. 5B, the molten resin 45 is filled in the space 43 formed by the injection molding core 20 and the mold surface 41A of the cavity. To eject. In the first embodiment, the space 43 is formed so as to surround the entire outer surface of the injection molding core 20. Further, a space 44 for forming the flange portion 33 is also formed. The injection conditions are exemplified below. Resin used: Nylon 66 Resin temperature: 305 ° C Resin injection pressure: 350 kgf / cm ² -G

The molten resin 45 is injected into the spaces 43 and 44, the resin in the spaces is cooled and solidified, and then the injection-molded product is taken out of the mold to obtain the injection-molded product shown in FIG. It is possible to mold a three-dimensional hollow molded product in which the entire outer surface of the core 20 is covered with the resin covering member 30.
In Example 1, the resin coating member 30 was made of nylon 66 and had a thickness of 2.5 mm.

Bonding surfaces 12, 13 of resin members 10, 11
Since continuous protrusions and recesses are formed in the core, the injection molding core 20 is caused by the resin injection pressure during the coating molding.
When a pressure is applied to the joint surfaces 12, a force is applied to the joint surfaces 12 and 13 in the self-locking direction. Moreover, the convex portion and the concave portion are continuous. As a result, it is possible to reliably prevent the molten resin from leaking into the hollow portion 21 of the injection molding core 20. Moreover, even if stress concentrates on the joint portion of the injection molding core 20, the stress is dispersed by the continuous convex portions and concave portions, and the joint portion does not shift. As a result, it is possible to prevent deformation and damage such as buckling of the injection molding core 20 (further, a three-dimensional hollow molded product).

(Embodiment 2) In Embodiment 2, as shown in the schematic perspective view of FIG. 6 (A), the resin is applied to an appropriate portion of the outer surface of the resin members 10 and 11 near the joint surface. A snap fit 50 for joining the manufactured members is provided. Any number of snap fits 50 may be provided. A schematic end view of the resin members 10 and 11 including the snap fit 50 taken along the line 6A-6A in FIG. 6A is shown in FIG. 6B. By engaging the snap fit 50, the resin members 10 and 11 can be easily and firmly joined together. Also, snap fit 5
By providing 0, there is an advantage that the manufacturing process of the three-dimensional hollow molded product can be simplified without using an adhesive or the like or joining the resin members by welding.

The molding method of the three-dimensional hollow molded article using the resin member provided with the snap fit 50 is substantially the same as that of the first embodiment except that the method of joining the resin members is different. Since the same method as the covering molding method for the three-dimensional hollow molded product described above can be applied, detailed description thereof will be omitted.

(Third Embodiment) The three-dimensional hollow molded article of the third embodiment includes a connecting member 60. The resin material forming the connecting member 60 is not particularly limited, but in view of the weldability with the resin coating member 30, it is preferable to use the same resin material as the resin coating member 30, for example.

The three-dimensional hollow molded article of Example 3 further includes a connecting member 60. Then, as shown in a schematic perspective view in FIG. 7, an uneven portion 122 is formed on a part of the outer surface of the injection molding core 120. On the other hand, the concavo-convex portion 61 that fits into the concavo-convex portion 122 formed on the outer surface of the injection molding core 120 is formed on the inner surface of the connecting member 60. Then, the uneven portion 61 formed on the inner surface of the connecting member 60
And the uneven portion 1 formed on the outer surface of the injection molding core 120.
22 by fitting, that is, the connecting member 6
The resin members are joined to each other by screwing 0 into the injection molding core 120 near the opening 121A.

In the third embodiment, the portion of the injection molding core 120 having the uneven portion 122 formed on the outer surface has a cylindrical shape. On the other hand, the connecting member 60 has a hollow cylindrical shape. The uneven portion formed on the outer surface of the injection molding core 120 and the inner surface of the connecting member 60 has a spiral shape.

The molding method of the three-dimensional hollow molding using the connecting member 60 is substantially the same as the three-dimensional hollow molding described in Example 1 except that the joining method of the resin members is different. Since it can be the same as the method for coating and molding the product, detailed description thereof will be omitted.

Although the third embodiment has been described with reference to an example in which the portion of the injection molding core 120 having the uneven portion 122 formed on the outer surface has a cylindrical shape, the shape of the portion of the injection molding core 120 is as follows. The shape is not limited to the cylindrical shape, and may be, for example, a rounded rectangular shape. In this case, a concavo-convex portion is formed on the outer surface of the portion of the injection molding core near the opening in parallel to the axis of the portion of the injection molding core. On the other hand, the inner surface of the connecting member having a cross-sectional shape similar to the cross-sectional shape of the injection molding core portion is fitted in parallel with the axis line of the uneven portion formed on the outer surface of the injection molding core. The uneven portion to be formed is formed. Then, the fitting member is inserted into the injection molding core near the opening while fitting the uneven portion formed on the outer surface of the injection molding core with the uneven portion formed on the inner surface of the connection member. As a result, the resin members can be joined.

In some cases, an uneven portion is formed on the inner surface (inner surface forming the hollow portion) of the injection molding core near the opening, while on the other hand, on the outer surface of the connecting member, on the inner surface of the injection molding core. An uneven portion that fits with the formed uneven portion may be formed. And an uneven portion formed on the outer surface of the connecting member,
The resin members are joined to each other by fitting the projections and depressions formed on the inner surface of the injection molding core, that is, by inserting or screwing the connecting member into the opening of the injection molding core. You can also

(Embodiment 4) As shown in the schematic view of FIG.
It is also possible to join the resin members 10 and 11 by winding the melt-spun fiber (for example, nylon fiber) 70 around the outer surface of the injection molding core while the resin members 10 and 11 are joined. After making the resin members 10 and 11 in such a joined state, the three-dimensional hollow molded article is produced by performing the same three-dimensional hollow molded article coating molding method as described in Example 1. You can In addition to the melt-spun fibers, glass fibers, carbon fibers, or films can be used, and two or more kinds of materials can be selected from these fibers or films and used.

When melt-spun fiber or film is used, its material is not limited, but in consideration of weldability, the same material as the resin members 10 and 11 or the same material as the resin coating member 30. It is desirable to select melt spun fibers and films from these materials. Alternatively,
It is also possible to use glass fibers or carbon fibers, and in this case, there is an effect of significantly improving the rigidity of the three-dimensional hollow molded article.

The resin member joining method described in the fourth embodiment can greatly simplify the structure and shape of the resin member as compared with the joining methods described in the second and third embodiments. There are advantages.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments.

The continuous convex portion formed on the joint surface of one resin member and the continuous concave portion formed on the joint surface of the other resin member described in Example 1 are shown in FIG. It can also be modified as shown in FIG.

Further, as shown in FIG. 9B, a continuous groove 14 may be formed in the region of the recess where two planes forming the continuous recess intersect. By providing such a groove 14, even if the molten resin enters between the joint surfaces during coating molding, the molten resin stagnates in the groove 14, so that the molten resin is effectively prevented from entering the hollow portion. can do.

As shown in the schematic end view in FIG. 9C, the cross-sectional shape of the continuous convex portion formed on the joint surface 12 of the one resin member 10 is a continuous curved surface that projects. be able to. In addition, the joint surface 1 of the other resin member 11
The continuous concave portion formed in 3 can be a continuous concave curved surface that fits with a convex portion formed of a protruding continuous curved surface.

As shown in the schematic end view in FIG. 9D, the resin members 10 and 11 near the joint surfaces 12 and 13 can be thickened. As a result, even if the pressure applied to the injection molding core having the hollow portion due to the coating resin injection pressure concentrates on the joint part of the injection molding core, the joint part of the injection molding core is deformed. It is possible to more reliably prevent damage and damage.

As shown in the schematic end view in FIG. 9E, the cross-sectional shape of the continuous convex portion formed on the joint surface 12 of the one resin member 10 is a continuous protrusion shape. You can Further, the continuous concave portion formed on the joining surface 13 of the other resin member 11 can be formed into a continuous groove shape that fits with the convex portion of the projection shape. It is desirable to make the depth of the groove-shaped recess deeper than the height of the protrusion-shaped projection. Even if the molten resin enters between the joint surfaces during coating molding, the molten resin stays in the groove-shaped recesses, so that it is possible to effectively prevent the molten resin from entering the hollow portion. is there.

As shown in the schematic end view of the three-dimensional hollow molded article of FIG. 10, the resin covering member 30 may cover only the outer surface of the joint portion of the injection molding core 20 and the vicinity thereof. .

[0064]

According to the present invention, since continuous protrusions and recesses are formed on the joint surface of the resin member, resin injection is performed when at least a part of the outer surface of the injection molding core is coated with resin. When a pressure is applied from the outside of the joining portion of the injection molding core due to the pressure, it is possible to reliably prevent the molten resin from leaking into the hollow portion from the gap of the joining portion of the injection molding core.

Further, the pressure applied to the joint portion of the injection molding core during the cover molding is dispersed at the joint portion of the injection molding core, and the joint surface of the resin member is not displaced.
As a result, it is possible to reliably prevent the joint portion of the injection molding core from being deformed or damaged by the pressure caused by the resin injection pressure. Therefore, it is possible to significantly improve the defective product generation rate during the production of the three-dimensional hollow molded product.

Furthermore, by providing a convex portion and a concave portion on the joint surface and adopting various joining means or joining methods, the joining of the resin members can be performed easily and surely, and three-dimensional hollow molding is possible. There is an advantage that the production process of the product can be simplified and the productivity can be improved. Further, when an adhesive is not used for joining the resin-made members, it is possible to prevent foreign matters from being mixed due to the melting of the adhesive due to heat at the time of coating molding, so that the weldability between the injection molding core and the resin-made covering member is improved. There is also an advantage of improving.

[Brief description of drawings]

FIG. 1 is a schematic perspective view and an end view of one resin member according to a first embodiment.

FIG. 2 is a schematic perspective view and end view of the other resin member in the first embodiment.

FIG. 3 is a schematic perspective view and end view of a three-dimensional hollow molded article of Example 1.

4A and 4B are a schematic perspective view and a schematic end view of the injection molding core of Example 1. FIG.

FIG. 5 is a partial cross-sectional view of a mold, an injection molding core, and the like, schematically showing the mounting of the injection molding core in the cavity and the injection state of the molten resin.

6A and 6B are a schematic perspective view and an end view of a resin member according to a second embodiment.

FIG. 7 is a schematic perspective view of an injection molding core and a connecting member according to a third embodiment.

FIG. 8 is a schematic perspective view of an injection molding core and the like of Example 4.

FIG. 9 is a schematic end view of a resin member for explaining various types of deformation of a joint surface of the resin member.

FIG. 10 is a schematic end view of a three-dimensional hollow molded product.

[Explanation of symbols]

 10, 11 Resin member 12, 13 Joining surface 14 Groove 20, 120 Injection molding core 21, 121 Hollow portion 21A, 121A Opening 30 Resin coating member 31 U-shaped portion 32 Linear portion 33 Flange portion 40 Gold Mold 41 Cavity 42 Metal Rod 43,44 Space 45 Molten Resin 50 Snap Fit 60 Connecting Member 61,122 Concavo-convex Part 70 Fiber

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Kakiki 5-6-2 Higashihachiman, Hiratsuka-shi, Kanagawa Sanryo Engineering Plastics Co., Ltd. Technical Center (72) Takayuki Ito 5th Higashihachiman, Hiratsuka-shi, Kanagawa 6-2 Sanryo Engineering Plastics Co., Ltd. Technical Center (72) Inventor Hideki Kinoshita 5-6-2 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Sanryo Engineering Plastics Co., Ltd. Technical Center

Claims (18)

[Claims] 1. An injection molding core having a hollow portion, which is formed by joining resin members preliminarily molded into a shape of at least two parts, and (b) the injection molding core. A three-dimensional hollow molded article comprising a resin-made covering member that covers at least a portion of the outer surface of the resin member, wherein a continuous convex portion is formed on the joint surface of the one resin member and the other resin member. The three-dimensional hollow molded article is characterized in that a continuous concave portion that fits with the convex portion is formed on the joint surface of. 2. The continuous convex portion formed on the joint surface of the one resin member is composed of two planes.
The angle θ ₁ (degrees) where the two planes intersect is 0 <θ ₁ <180, and the two continuous recesses formed on the joint surface of the other resin member are also two planes. The three-dimensional hollow molded article according to claim 1, wherein the intersecting angle θ ₂ (degrees) is θ ₂ = 360−θ ₁ . 3. The three-dimensional hollow molded article according to claim 2, wherein a continuous groove is formed in a region of the recess where two planes forming the continuous recess intersect. 4. The three-dimensional hollow molded article according to claim 1, wherein the continuous convex portions and concave portions formed on the joint surface of the resin member are curved surfaces. 5. The three-dimensional hollow molded article according to any one of claims 1 to 4, wherein a portion of the resin member near the joint surface is thickened. 6. The snap fit for joining the resin member is formed on the outer surface of the resin member near the joint surface, according to any one of claims 1 to 5. The three-dimensional hollow molded article described. 7. The three-dimensional hollow molded article further includes a connecting member, wherein an uneven portion is formed on an outer surface of a part of the injection molding core, and the inner surface of the connecting member is for injection molding. An uneven portion that fits with the uneven portion formed on the outer surface of the core is formed, and the uneven portion formed on the inner surface of the connecting member and the uneven portion formed on the outer surface of the injection molding core are formed. The three-dimensional hollow molded article according to any one of claims 1 to 5, wherein the resin members are joined by fitting. 8. An injection molding core having a concavo-convex portion formed on the outer surface thereof has a cylindrical shape, and a connecting member has a hollow cylindrical shape. The three-dimensional hollow molded article according to claim 7, wherein the uneven portion formed on the inner surface has a spiral shape. 9. A three-dimensional hollow molded article is a melt-spun fiber,
A resin member is bonded by further including at least one kind of material selected from the group consisting of glass fiber, carbon fiber and film, and winding the material around the outer surface of the injection molding core. The three-dimensional hollow molded article according to any one of claims 1 to 5. (A) A resin member preformed in a shape of at least two parts, wherein a continuous convex portion is formed on the joint surface of one resin member, and the other one is formed. A step of joining a resin member in which a continuous concave portion that fits with the convex portion is formed on a joint surface of the resin member to form an injection molding core having a hollow portion; After mounting the injection molding core in the mold cavity, a molten resin is injected into the space formed by the injection molding core and the mold surface of the cavity, whereby the injection molding is performed. A method for coating and molding a three-dimensional hollow molded article, which comprises the step of coating at least a part of the outer surface of the core with a resin. 11. A continuous convex portion formed on a joint surface of the one resin member is composed of two planes, and an angle θ ₁ (degree) at which the two planes intersect is 0 <θ ₁ <. 180, and the two continuous recesses formed on the joint surface of the other resin member are also composed of planes, and the angle θ ₂ (degrees) at which the _two planes intersect is θ ₂ = 360−θ ₁ The method for coating and molding a three-dimensional hollow molded article according to claim 10, wherein 12. The method for coating and molding a three-dimensional hollow molded article according to claim 11, wherein a continuous groove is formed in a region of the recess where two planes forming the continuous recess intersect. 13. The method for coating and molding a three-dimensional hollow molded article according to claim 10, wherein the continuous convex portions and concave portions formed on the joint surface of the resin member are curved surfaces. 14. The resin member in the vicinity of the joint surface is thickened.
The method for coating and molding a three-dimensional hollow molded article according to any one of 1. 15. A snap fit is formed on the outer surface of the resin member in the vicinity of the joint surface, and the resin member is joined by the snap fit.
The method for coating and molding a three-dimensional hollow molded article according to any one of claims 0 to 14. 16. A connection in which an uneven portion is formed on an outer surface of a part of the injection molding core, and an uneven portion which fits with the uneven portion formed on the outer surface of the injection molding core is formed on the inner surface. A resin member is joined by fitting a concave-convex portion formed on the outer surface of the injection molding core and a concave-convex portion formed on the inner surface of the connecting member using the member for molding. 10 to claim 1
The method for coating a three-dimensional hollow molded article according to any one of 4 above. 17. An injection molding core having a concavo-convex portion formed on an outer surface thereof has a cylindrical shape, and a connecting member has a hollow cylindrical shape. The method for coating and molding a three-dimensional hollow molded article according to claim 16, wherein the uneven portion formed on the inner surface has a spiral shape. 18. A resin member is joined by winding at least one material selected from the group consisting of melt-spun fibers, glass fibers, carbon fibers and films on the outer surface of an injection molding core. The method for coating and molding a three-dimensional hollow molded article according to any one of claims 10 to 14, which is characterized.