JP3643820B2 - Dissimilar / different color integrated injection molding method and apparatus - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an injection molding method and apparatus for manufacturing an integrated product made of different materials and different color materials at low cost and efficiently.
[0002]
[Prior art]
Conventionally, in order to injection-mold a molded product made of different materials or different colored materials, a partial product made of one material is molded in advance by injection molding, and this partial product is set in another molding die. These parts are manufactured by so-called insert molding in which injection molding is performed.
[0003]
[Problems to be solved by the invention]
However, according to the above-described insert molding method, the pre-molded part is naturally cooled, and in the process, deformation such as sink marks and dents occurs at the thick part where the reinforcing ribs intersect, and so on. Has a problem that burrs and the like are generated in this portion. In addition, since the parts are naturally cooled, the adhesion to the product parts by the next injection molding is poor, and in particular, dissimilar materials such as nylon product parts with a melting point of 230 ° and polyethylenes with a melting point of 140 ° to 150 ° Even if it is going to shape | mold the product part of this by insert molding, since melting | fusing point differs greatly, there exists a subject that it hardly adheres. Therefore, in order to improve the adhesion, it has been tried to reheat the part to be inserted before reinserting, but it takes a lot of time and labor, and the problem is that warping and distortion due to reheating occur in the part. There is.
[0004]
In recent years, as shown in FIG. 9, one split mold (core mold) of two sets of molding dies is attached to one rotating shaft and can be moved laterally, and the other split mold is located at a distance in the moving direction. (Cabinet molds) are fixedly attached to each other, and the primary product is molded by injection, and the primary product is left in the core mold. Proposal of a two-color molding device that molds as it is, further rotates 180 degrees, closes and closes the mold on the other side 2 and performs injection molding of the secondary product (similarly, rotates vertically and vertically) There is something to move). According to this means, the secondary product is molded while the molded primary product is not cooled, but the adhesion is good, but it is necessary to mold two types of product shapes with one core mold. As a result, the shape of the product to be manufactured is limited to a relatively simple one. In addition, two sets of molding devices are linked like a set of molding devices, or the secondary product is molded after the primary product is molded. Therefore, it is necessary to manufacture a core mold with complex and large-scale functions and structures that can change to both product shapes, so the mold cost becomes very expensive, and it takes a long time from order to delivery. There is a problem that it ends up.
[Means for Solving the Problems]
The present invention provides two or a plurality of molding dies for molding different parts and a common nest that can be mounted in common to the respective molding dies, and the common nest is formed in one molding die. Mold the product part by injection molding in the cavity that can be installed, take out the common nest before the product part cools down, and attach it to the next molding die so that it is in close contact with the product part. Thus, such a problem is solved by injection-molding product parts of different / different color materials.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of an integrally molded product of different materials that can be molded according to the present invention. A pipe-shaped main body 1 having a widened portion 1a on one side made of nylon and an intermediate periphery of the main body 1 And a ring-shaped ring-shaped body 1b made of a polyethylene material. In addition, 1c is a protruding ring for reinforcing adhesion.
[0006]
In order to mold such a product, the common insert 3 is first installed in the first core mold 2a as shown in FIG. 2, and then the mold 2b is abutted and closed as shown in FIG. The annular body 1b is molded by injecting the molten polyethylene material P from the injection nozzle 5a into the molding cavity 4a formed by the molds 2a, 2b and the common nest 3. Next, as shown in FIG. 4, the mold 2 b is opened and separated, and the formed ring body 1 b is taken out together with the common nest 3. FIG. 5 (a) is a plan sectional view of the common nest 3 and FIG. 5 (b) is a front view thereof. In the figure, 3a is a protruding pin for insertion / removal handling. As shown in FIG. 6, the common nest 3 is continuously mounted in the second core mold 2c before the ring 1b is cooled, and the molds 2d, 2e and The melted nylon material N is injected from the injection nozzle 5b into the molding cavity 4b formed by butting and closing 2f, and the main body 1 portion is molded in close contact with the annular body 1b.
[0007]
Since the main body 1 is injection-molded while the temperature of the previously formed annular body 1b is high (semi-molten state), an integrated product can be manufactured with high adhesion even with different materials having different melting points. . Further, since the ring body 1b moves together with the common nest 3, there is no possibility of deformation or the like.
[0008]
A plurality of common nests 3 are prepared, and continuous molding can be carried out by eliminating molding idle time by repeatedly performing molding, moving, cooling, demolding, and remounting. Operations such as mounting, taking out of the common nest 3 and movement / mounting to the next mold in parallel are performed by a robot-like automatic machine (not shown) protruding and holding the pin 3a. An operator can also do it.
[0009]
The example of the integral molding with two different materials has been described above, but the integral molding with the same kind of different color material / different kind of different color material can be performed in the same manner. Also, it is easy by preparing third and subsequent molds that can form complex shapes with more than 3 injection processes with 2 types / 2 color materials, and can also be integrated with 3 types, materials with more than 3 color materials. Can be realized.
[0010]
【The invention's effect】
As described above, the present invention provides two or a plurality of molding dies for molding different parts and a common nest that is formed so as to be mountable in common to the respective molding dies. The product is molded by injection molding into a molding cavity formed by attaching the common insert to the mold, and the common insert is taken out and attached to the next molding die before the product part cools down. The product parts of different / different color materials that are in close contact with the product parts in the cavity formed by closing are injection-molded and sequentially and integrally formed in one piece. This significantly improves the quality of the insert product as in conventional insert molding, prevents deformation of the insert product, generates burrs, and the like, thereby effectively producing a high-quality product that does not require post-processing.
[0011]
Molding can be performed with a mold with the same simple structure as before, so that the mold cost does not rise and the mold manufacturing period does not become long. The product can be produced from the design in a short period of time and at a low cost.
[Brief description of the drawings]
FIG. 1 shows an example of a product to be molded according to the present invention, where (a) is a perspective view and (b) a cross-sectional view. FIG. 2 shows a state where a common nest is mounted in a first core mold. Fig. 3 is a plan sectional view showing a state where a molten metal is injected from an injection nozzle into a cavity formed by abutting and closing the mold, and a product part is molded. Fig. 5 (a) is a cross-sectional plan view of the product part and the common nest, and Fig. 5 (b) is a front view of the same. Fig. 6 is a cross-sectional plan view showing a state in which product parts are mounted in a second core mold together with a common insert. Fig. 7 is a cross-sectional plan view showing a state in which a part of a mold is closed together. A product formed by injection molding into a cavity created by attaching all molds and molding the product part in one piece. Front view illustrating an example of a cross-sectional plan view and FIG. 9 conventional two-color molding machine showing the EXPLANATION OF REFERENCE NUMERALS
Reference numeral 1 denotes a main body 1b, a housing 1c, a protruding ring 2a, a first core mold 2b, a first cabinet mold 2c, a second core mold 2d, 2e, 2f, a second cabinet mold 3. The common nest 3a protrudes and the pins 4a and 4b are second cavities 5a and 5b are injection nozzles.

Claims (2)

Two or a plurality of molding dies for molding different parts and a common nest that is formed so as to be attachable to each of the molding dies are prepared. The product part is molded by injection molding into a cavity that can be closed, and the product part is taken out before the product part cools down and attached to the next molding die, and the mold is closed and integrated with the product part. A different / different color material integrated injection molding method, wherein product parts of different / different color materials are injected and sequentially molded so as to be in close contact with each other. It is composed of two or more molding dies for molding different parts, and a common nest that can be attached to each molding die and can be taken out together with the molded product. A product part that is molded by injection into a molding cavity formed by mounting the common nest, and a molding that can be taken out of the common nest and mounted on the next molding die and closed. A different / different color integrated product is sequentially formed by injection molding of a product portion that is in close contact with the product part by injection of the different / different color material into a cavity for use. Material-integrated injection molding equipment.

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