JPH089203B2 - Synthetic resin intake pipe for engine and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a synthetic resin intake pipe used in an automobile engine and a method for manufacturing the intake pipe.

(Prior Art) Conventionally, as a method for manufacturing a synthetic resin intake pipe, for example, the one disclosed in JP-A-58-82059 is known.

In this conventional manufacturing method, a hollow core formed of a low melting point alloy is prepared in advance, the hollow core is set in an injection molding die, and then a thermoplastic synthetic resin is injected into the die. ,
After the resin is solidified, the resin is not melted and heated at a temperature at which only the hollow core made of the low melting point alloy is melted, and the hollow core is eluted to obtain a synthetic resin intake pipe.

(Problems to be Solved by the Invention) However, in this conventional manufacturing method, the hollow core has to be formed every time one synthetic resin intake pipe is manufactured, and Since the heating process with temperature control was required when the hollow core was eluted, a large number of steps, time and cost were required, and the thickness of the product varied due to the accuracy of setting the hollow core. It was easy, and lacked stability in terms of strength and quality.

In addition, when molding the duct part and the functional part at the same time by injection molding, the thickness of the duct part must be made thicker than necessary, and it is not possible to significantly reduce the weight, and the injection mold shape becomes large and complicated. Turn into. Furthermore, since the injection pressure is applied to the entire outer peripheral portion of the hollow core, the hollow core is likely to be deformed by the injection pressure.

(Means and Method for Solving Problems) The present invention aims to solve the above problems, and in order to achieve this object, the synthetic resin intake pipe for an engine of the present invention is formed by blow molding only. And a duct part that uses the internal space as an intake passage, and is integrally provided by injection molding on a part of the outer circumference of the duct part, and has ancillary functions other than the intake function such as the flange part, the ventilation pipe, and the mounting screw part. It is characterized in that it is composed of a functional part which is a part to be achieved.

Further, in the method for manufacturing a synthetic resin intake pipe for an engine of the present invention, a synthetic resin duct portion is molded with blowability, and the duct portion is arranged as a core in an injection molding die having a functional portion molding surface. After that, the synthetic resin material is injected into the mold, and a functional portion made of the synthetic resin material is integrally formed on a part of the outer circumference of the duct portion as the core.

The functional part means a flange part, a ventilation pipe, a mounting screw part, and the like.

(Operation) Therefore, according to the method for manufacturing an engine synthetic resin intake pipe of the present invention, the synthetic resin duct part formed by blow molding becomes a product as it is while performing the function of the core during injection molding. Therefore, an independent core forming step and a core elution step by heating are not required, and the steps can be omitted.

Also, because the duct is formed only by blow molding,
The weight of the intake pipe can be reduced, and since the functional parts are partially formed by injection molding, the injection mold shape can be made smaller. It simplifies, the deformation of the duct portion due to the injection pressure hardly occurs, it is possible to omit the filling material inside the duct portion during injection molding, and the mounting strength of the functional portion can be secured.

(Examples) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a synthetic resin intake pipe for an engine (hereinafter referred to as an intake pipe) according to the present invention.

The intake pipe 10 includes a duct portion 11 formed only by blow molding, a flange portion (functional portion) 12 integrally formed at an end portion of the duct portion 11 by injection molding, and a duct portion 11
A ventilation pipe (functional part) 13 integrally formed by injection molding in the middle of the above, and a mounting screw part (functional part) 14 integrally formed by injection molding in the middle of the duct part 11 .

A pickup pipe of an intake air amount sensor, a blow-by gas recirculation pipe, and the like are connected to the ventilation pipe 13.

 Further, the internal space of the duct portion 11 becomes the intake passage 15.

Next, a method of manufacturing the intake pipe 10 shown in FIG. 2 will be described step by step.

First, as shown in FIG. 2 (a), a bent pipe 20 conforming to the shape of the duct 11 in the target intake pipe 10 is formed by blow molding.

As is well known, blow molding allows molding of the bent pipe 20 even if it has a complicated shape of two dimensions or more.

Next, as shown in FIG. 2B, a bent tube 20 having a sufficient thickness in consideration of deformation is set as a core in the injection molding die 21 having the functional portion molding surfaces 21a, 21b, 21c. .

This setting is performed according to a conventional method so that the core does not move during injection molding.

In this state, as shown in FIG. 2C, the synthetic resin material is injected into the injection molding die 21 to fill the space formed by the die 21 and the bent pipe 20. The molding conditions at this time are:
Take into consideration the shape, etc. according to the usual method.

As a result, the bent pipe 20 serves as the duct part 11 as it is, the injected synthetic resin material is integrally welded to the outside of the duct part 11, the flange part 12 is provided at one end, and the ventilation pipe 13 and the bent pipe 13 are provided at the bent part. A mounting screw portion 14 is formed.

When the molding is completed, the mold 21 is opened to take out the molded product, and a hole having the same diameter as the inner diameter of the ventilation pipe 13 is formed in the duct portion 11 to form the pipe hole 13a, as shown in FIG. The intake pipe 10 can be obtained.

It should be noted that the injection mold 21 may be divided into functional parts or divided into predetermined groups.

Further, as the resin material, it is preferable to use the same kind of resin having good adhesiveness, a material having a low permeability of gasoline or blow-by gas in terms of physical properties, and a material having high strength, for example, reinforced with glass fiber or carbon fiber. There are combinations of nylon 6 and nylon 66.

As described above, according to the intake pipe 10 and the method of manufacturing the same of the present embodiment, the following effects can be achieved.

Bent pipe made of synthetic resin molded by blow molding
Since 20 serves as the duct part 11 as it is while performing the function of the core during injection molding, an independent core molding step and core elution step by heating are unnecessary, and the intake pipe 10 made of synthetic resin
The number of processes is small, and it can be manufactured in a short time and at low cost.

Since the duct part 11 is formed only by blow molding,
In terms of strength, the thickness can be set based on the required strength of only the duct portion 11, and the weight of the intake pipe 10 can be reduced.

Since the flange portion 12, the ventilation pipe 13 and the mounting screw portion 14 which are the functional portions are partially formed by injection molding, the injection mold can be downsized and simplified.

Since the duct part 11 serving as the core is formed with a predetermined strength, the duct part 11 is unlikely to be deformed by the injection pressure, and as a result, it is possible to omit filling the inside of the duct part 11 during injection molding. .

Since the flange 12, ventilation pipe 13 and mounting screw 14 that are functional parts are integrally formed by heat welding during injection molding, there is no need for molding or joining in a separate process, and strength is reliable even when receiving external force. It is highly likely.

Although the present invention has been described above with reference to the embodiment, the specific product and the manufacturing method are not limited to this embodiment, and the shape of the product and the addition of steps are added within the scope not changing the gist of the present invention. Even if there is a change in process or process, it is included in the present invention.

For example, in the above embodiment, the case where the wall thickness of the duct portion 11 is made substantially uniform has been described, but the wall thickness may be changed according to the strength requirement.

In this case, the blow molding may be arbitrarily selected.

Further, the curved shape is not limited to one place, and may be provided at a plurality of places. Also in this case, since it can be treated during blow molding,
No special treatment is required during injection molding.

Further, in the embodiment, the example of the flange portion, the ventilation pipe, and the mounting screw portion is shown as the functional portion. However, even if it is a combination of one or two kinds of these, another functional portion is added. Is also good.

Further, when the intake pipe according to the present invention is attached to an engine, it may be a type provided at a place for directly sucking the outside air,
A type that is connected to the supercharged side of the turbocharger may be used.
Further, it is not limited to the method of directly attaching to the engine, but may be a type provided in a path forming an intake passage communicating with the engine.

(Effects of the Invention) As described above, in the present invention, since the duct part made of synthetic resin molded by blow molding functions as a core during injection molding and becomes a product as it is, independent core molding The process and the core elution process by heating become unnecessary, and the process can be omitted.

Also, because the duct is formed only by blow molding,
The weight of the intake pipe can be reduced, and since the functional parts are partially formed by injection molding, the injection mold shape can be made smaller. This simplifies, the deformation of the duct portion is less likely to occur due to the injection pressure, it is possible to omit the filling material inside the duct portion at the time of injection molding, and it is possible to secure the attachment strength of the functional portion.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an engine synthetic resin intake pipe according to the present invention, and FIG. 2 is an explanatory view showing a manufacturing process of the embodiment. 10 …… Synthetic resin intake pipe for engine 11 …… Blow molding duct 12 …… Injection molding flange (functional part) 13 …… Injection molding ventilation pipe (functional part) 14 …… Injection molding Mounting screw part (functional part) 21 ... Injection mold

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Claims (2)

[Claims] 1. A duct portion formed only by blow molding and having an internal space as an air intake passage, and a portion of the outer periphery of the duct portion integrally provided by injection molding, and having a flange portion, a ventilation pipe, a mounting screw portion, and the like. A synthetic resin intake pipe for an engine, which is configured by a functional part that is a part that achieves an auxiliary function other than the intake function of. 2. A synthetic resin duct part is formed by blow molding, the duct part is placed as a core in an injection molding die having a functional portion molding surface, and then a synthetic resin material is injected into the die. A method for manufacturing a synthetic resin intake pipe for an engine, wherein a functional portion is integrally formed of a synthetic resin material on a part of an outer periphery of a duct portion as a core.