JPH04135717A - Composite pipe of synthetic resin and metal and its manufacture - Google Patents

Abstract

PURPOSE:To enable a composite pipe of synthetic resin and metal with a complicated shape of at least two dimensions to be easily produced and moreover to provide it at a low price thereof by a method in which synthetic resin is injection-molded on the part or the whole of the outer periphery of the metallic pipe preliminarily formed into an aimed shape, whereby the pipe is integrally covered with the resin. CONSTITUTION:An intake manifold 10 is composed of the inner layer 1 of a metallic pipe and the outer layer 2 of synthetic resin, and the part or the whole of the outer periphery of the metallic pipe as the inner layer 1 can be covered with the synthetic resin as the outer layer 2 in some cases. In the intake manifold 10, the metallic pipe 1 preliminarily formed into shape of the intake manifold 10 is used as a core, and synthetic resin 2 is injection-molded on the part or the whole of the outer periphery of the core, whereby the core is integrally covered. In its manufacture, the metallic pipe 1 formed into the shape of the intake manifold is set in the mold 9 as the core 11. Accordingly, molten synthetic resin is injected into the mold 9 through a sprue 13 from a nozzle 6, and the part or the whole of the core is covered with the resin.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a synthetic resin/metal composite pipe used for, for example, intake manifolds, surge tanks, delivery pipes, air ducts, etc. as automobile parts, and a method for manufacturing the same. Regarding.

[Prior Art] Conventionally, a composite pipe made of synthetic resin and a method for manufacturing the same are known as disclosed in Japanese Patent Application Laid-Open No. 1-156025. This synthetic resin composite pipe is made by integrally covering the outer periphery of a blow-molded synthetic resin curved pipe 30 with a positioning part 21 at the end by injection molding, as shown in FIG. As shown in FIG. 5, the manufacturing method is as follows: First, as shown in FIG. The tips of the sliding bending tube 3o are removed from the vicinity of the positioning parts at both ends, and then, as shown in FIG. The material 31 is filled, both ends are closed 33, and this is inserted as a core into the injection mold 32 as shown in FIG. After contacting and clamping the mold, the same figure (d)
A synthetic resin material is injected into the space 34 between the blow molded synthetic resin curved pipe 30 and the wall surface of the injection mold 32, and the synthetic resin material 22 is integrated around the outer periphery of the blow molded synthetic resin curved pipe 30. It is intended to cover the surface.

[Problems to be Solved by the Invention] According to the conventional synthetic resin composite tube and its manufacturing method as described above, it is possible to reduce the weight, and the blow-molded synthetic resin die tube can reduce product variations and reduce manufacturing time. This eliminates the wobbling of the core and the variation in inner thickness due to poor core setting, but there are the following problems.

fa) Since the entire product is made of synthetic resin, its mechanical strength is low.

(b) With blow molded products, it is difficult to mold three-dimensional complex shapes.

(c) Since a filler must always be placed inside the tube of a blow-molded product, the filler is not only necessary, but also increases the number of man-hours for filling, taking out, and recovering the filler, which increases costs accordingly.

In view of these points, it is an object of the present invention to provide a synthetic resin/metal composite pipe that solves the above-mentioned drawbacks and a method for manufacturing the same.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention includes a method in which a part or the entire outer periphery of a metal vibrator that has been previously formed into a desired shape is integrally coated with a synthetic resin by injection molding. A metal vibrator previously formed into a desired shape is set in an injection mold as a core of an injection molding machine, and a synthetic resin material is injected into a part or the entire outer periphery of the metal vibrator. , a second part that integrally coats a part or the entire outer periphery of the metal vibrator with a synthetic resin.
The claim is as follows.

[Operation J] A synthetic resin/metal composite tube is one in which an inner layer made of metal and an outer layer made of synthetic resin are integrally formed, and a metal vibrator is used for the inner layer made of metal.

The metal vibrator as the inner layer acts as a core during injection molding, and the synthetic resin as the outer layer is injection molded and integrally coated on the outer periphery of the metal vibrator as the core.

[Example] The present invention will be explained in detail with reference to Figs. 1 to 3 below. Figs. 1 and 2 show the case where the synthetic resin/metal composite pipe according to the present invention is applied to an intake manifold. FIG. 1 is a perspective view showing an intake manifold 10 which is composed of an inner thickness 1 of a metal tube and an outer layer N2 made of synthetic resin. FIG. FIG. 2 shows a case where the entire outer layer 2 is coated with a synthetic resin.

The intake manifold 10 has a metal vibe 1 installed in advance.
A core is formed by molding into the shape of the intake manifold 10, and a part or the entire outer periphery of the core is integrally coated with a synthetic resin 2 by injection molding.

Next, the method for manufacturing the intake manifold 10 is as follows:
To explain FIG. 3, FIG. 3 is an explanatory diagram showing an example of an injection molding machine in cross section, and shows a heating cylinder 3. Heater 4
．． Torpedo 5. The mold consists of a nozzle 6, a hopper 7, a plunger 8, and a mold 9, in which the thermoplastic resin molding material 12 in the hopper 7 is heated and melted in a heating cylinder (heating cylinder) 3, and the mold is closed from the nozzle 6 with a plunger 8. It is injection molded inside 9. At this time, a metal vibrator 1 molded into the shape of an intake manifold is set in the mold 9 as a core 11.

Therefore, the molten synthetic resin is injected from the nozzle 6 through the sprue 13 into the mold 9, and covers part or all of the outer periphery of the core 11. That is, a part or the entire outer periphery of the metal vibrator 1 as the inner layer is coated with the synthetic resin 2 as the outer layer. The thickness of the synthetic resin 2 as the outer layer at this time is determined by the gap between the outer peripheral surface of the core 11 and the inner wall surface of the mold 9, so if you want to make it thicker, widen the gap, and if you want to make it thinner, make the gap wider. Just make it narrower.

In addition, the wall thickness of the metal vibrator 1 as an inner layer can be freely set during manufacturing, but if the wall thickness is made as thin as possible, pressure will be applied during injection molding and it will deform.
Non-deformable material 1 that can withstand pressure during injection molding, such as sand, water,
Heat oil or the like (approximately 80°C), fill it, and close the openings at both ends to form. In this way, even a thin metal pipe l can be formed without deformation.

The mold 9 is divided into 9a and 9b so that the core 11 can be set and the finished product can be taken out.However, since pressure is applied during injection molding, the mold is clamped by a mold clamping mechanism (not shown). has been done.

The molding conditions when injecting synthetic resin with an injection molding machine are as follows:
This is done in accordance with a conventional method, taking into consideration the materials used, shape, etc.

The thick metal pipe 1 is made of, for example, aluminum, iron, copper, etc., and the desired shape can be formed by casting in the desired shape, forming with a pipe bender, etc. A conventionally known method may be used, and therefore, even complex three-dimensional shapes can be easily formed.

Then, the metal pipe molded into the desired shape is set as the core of an injection molding machine, and synthetic resin is injected to cover part or all of the outer circumference of the metal pipe as the core to form an outer layer. Since the metal pipe as the inner layer can be easily formed into a three-dimensional complicated shape, even a synthetic resin/metal composite pipe with a complicated shape can be easily formed. Therefore, in the past, it was very difficult to mold curved pipes such as intake manifolds that had a complicated shape of two or more dimensions because the core could not be removed at the stage of cutting out the mold after molding. According to the method, it can be easily formed.

[Effects of the Invention] As explained above, according to the synthetic resin/metal composite pipe according to the present invention, (1) heat resistance is improved compared to resin products.

■Higher strength than resin products.

■Compared to resin products, there is no need to consider durability against gasoline, etc., and inexpensive materials can be used for the outer layer.

■Inner surface roughness is improved compared to cast products, improving intake efficiency.

■Significant weight reduction compared to cast products.

■Compared to cast products, post-processing of flange parts, etc. is not required.

It has the following effects.

Furthermore, according to the method for manufacturing synthetic resin/metal composite pipes of the present invention, synthetic resin/metal composite pipes with two-dimensional or more complex shapes can be easily manufactured, and a core in the original sense is unnecessary. This has the advantage that it can be provided at a low cost.

[Brief explanation of the drawing]

1 and 2 are perspective views of the synthetic resin/metal composite pipe according to the present invention applied to an intake manifold, FIG. 3 is a cross-sectional explanatory view showing the manufacturing method of the present invention, and FIG.
The figure is a sectional view showing a conventional example, and FIGS. 5(a) to 5(d) are explanatory diagrams showing the conventional manufacturing process. DESCRIPTION OF SYMBOLS 1... Metal pipe as inner layer, 2... Synthetic resin coating as outer layer, 1o... Intake manifold, 11... Metal pipe as core. Patent applicant: Aisin Seiki Co., Ltd., 2-1 Asahi-cho, Figure 2, Aisin Seiki Co., Ltd.

Claims (2)

[Claims] (1) A synthetic resin/metal composite pipe made by integrally covering a part or the entire outer periphery of a metal pipe into a desired shape with synthetic resin by injection molding. (2) A metal pipe previously formed into the desired shape is set in the injection mold as the core of the injection molding machine, and a synthetic resin material is injected onto part or all of the outer periphery of the metal pipe. A method for producing a synthetic resin/metal composite pipe, which comprises integrally covering a part or the entirety of the pipe with a synthetic resin.