KR20040020668A - Method for manufacturing intake manifold for noise reduction - Google Patents

Abstract

PURPOSE: A method for manufacturing an intake manifold is provided to improve the efficiency of noise reduction and to reduce manufacturing cost by manufacturing a double-structured surge tank and a runner with different materials. CONSTITUTION: In a method for manufacturing an intake manifold composed of a surge tank and a runner, a surge tank part and a runner part are inserted into a cavity in a mold. The surfaces of the surge tank part and runner part are overmolded with nylon resin or elastomer. Thus, the double-structured surge tank and runner are manufactured with different materials.

Description

Manufacturing method for automobile intake manifold for noise reduction {Method for manufacturing intake manifold for noise reduction}

The present invention relates to a method for manufacturing a vehicle intake manifold for noise reduction, and more particularly, to reduce the transmission noise in the upper part of the surge tank, which is the main noise of the intake manifold, to increase the thickness of the surge tank. Instead of the conventional noise reduction method that covers or covers the surge tank with a cover, insert the surge tank and runner part of the intake manifold into the cavity in the mold, and then apply nylon resin or elastomer material to the surface of the surge tank and runner. The present invention relates to a method for manufacturing an intake manifold for automobiles, which is manufactured by overmolding a foam injection molding method and manufacturing the surge tank and the runner in a heterogeneous dual structure, thereby making it possible to manufacture an intake manifold having excellent noise reduction effect.

Generally, an intake manifold is mounted on the head side of the engine, and serves to supply air and fuel necessary for combustion of the engine inside the cylinder.

The intake manifold is equipped with a throttle body (air throttle body) through which the air inlet and the amount of inlet air is controlled, a surge tank (surge tank) to allow the inlet air to stay, and the inlet air It is comprised by the detail of the runner which distributes suitably and supplies to each cylinder.

Normally, the runner of the intake manifold is composed of three or four runners, which are mounted to the head of the engine, through which air and fuel are supplied into the cylinder.

Airflow noise generated when air enters the intake manifold mainly passes through the top of the surge tank, causing external noise.

Recently, in order to reduce the weight and performance of engines, the intake manifold has been expanded to plastics based on nylon resin having heat resistance reinforced with glass fiber instead of aluminum, and there is an urgent need for a method for reducing noise. It is becoming.

The plastic material is known to have noise during inflow into the vehicle, making NVH (Noise-Vibration-Harnish) worse than aluminum specifications.

On the other hand, the conventional method used to reduce the noise of the intake manifold is first, the vibration noise generated by the engine vibration is transmitted to the intake manifold is designed to increase the thickness or rib application to increase the rigidity of the intake manifold Second, the airflow inside the intake manifold transmitted through the upper part of the surge tank increases the thickness by increasing the thickness, or when this alone is not sufficient to reduce the noise, EPDM inside the cover of the injection molding. Rubber pads are cut and bonded with double-sided tape, and the cover is wrapped around the surge tank and fixed with mounting bolts.

However, in the conventional intake manifold manufacturing process, a step of molding a separate injection molded article (2 pieces), a step of attaching a foam pad to the inside of the cover which is the injection molded article, and assembling the cover thus produced to the intake manifold In addition to the addition of several steps for the cover, such as the process, there is a problem that the increased labor and material costs cause a cost increase, in particular, there is a disadvantage in terms of recycling by using a foam pad made of rubber material.

In addition, there was a problem of increasing the thickness of the intake manifold and the weight increase due to the application of the cover, and in particular, the increase in the thickness of the intake manifold had a molding problem, and the layout of the engine parts was not easy to realize.

In addition, it is true that it is difficult to expect a sufficient noise reduction effect only by increasing the thickness of the intake manifold itself or by applying a cover to cover the outside of the surge tank.

Therefore, the present invention is invented to solve the above problems, in order to reduce the transmission noise in the upper part of the surge tank, which is the main noise of the intake manifold, to increase the thickness of the surge tank or to increase the surge tank. Instead of the conventional noise reduction method that covers the cover, insert the surge tank and runner part of the intake manifold into the cavity in the mold, and then foam injection molding nylon resin or elastomer material on the surface of the surge tank and runner. By manufacturing the surge tank and the runner in a heterogeneous double structure by overmolding, it is possible to manufacture an intake manifold with excellent noise reduction effect, and to manufacture a car intake manifold that can reduce manufacturing costs while simplifying the work process. The purpose is to provide a method.

1 is a schematic diagram of a test apparatus for measuring the amount of transmission loss of sound.

<Explanation of symbols for the main parts of the drawings>

10: anechoic chamber 11: speaker

12: test piece and part 13a: first microphone

13b: second microphone 14: signal analyzer

15: control device

Hereinafter, the present invention will be described in detail.

The present invention provides a method for manufacturing an intake manifold for automobiles consisting of an air inlet, a surge tank and a runner,

After inserting the surge tank and the runner portion of the intake manifold into the cavity in the mold, the surge tank and the runner are overmolded by foam injection molding of nylon resin or elastomer material on the surfaces of the surge tank and the runner. It is characterized by the production of a double structure of a heterogeneous material.

In particular, when the injection molding of the nylon resin or elastomeric material by using carbon dioxide or nitrogen to foam to a foaming rate of 10 to 20% characterized in that the overmolding.

Hereinafter, the present invention will be described in more detail.

The present invention, in order to reduce the transmission noise in the upper part of the surge tank, which is the main noise of the intake manifold, instead of increasing the thickness of the surge tank or the conventional noise reduction method of covering the surge tank with a cover, the surge tank And a method of manufacturing an intake manifold by overmolding the surge tank and runner with the nylon resin or elastomeric material by foam injection molding a nylon resin or elastomeric material to a runner. will be.

That is, in the manufacturing method of the intake manifold of the present invention, the surge tank and the runner are overmolded with a nylon resin or an elastomeric material using a foaming method having excellent noise absorption characteristics to manufacture the intake manifold.

Hereinafter, the intake manifold is a part that includes the surge tank in a broad concept, rather than a consensus concept meaning that it is an independent structure from the surge tank.

When explaining the manufacturing method of the intake manifold for noise reduction according to the present invention, first, the surge tank and the runner portion of the intake manifold is inserted into the cavity in the mold.

Then, the injection molding of the nylon resin or elastomer material excellent in the transmission loss effect on the surface of the surge tank and the runner, but applying the foaming method.

When the injection molding method of the nylon resin or elastomer material is applied to the surface of the surge tank and the runner by applying the foaming method as described above, the surge tank and the runner of the intake manifold are overmolded with the nylon resin or the elastomer material and thus different materials It becomes the dual structure of.

In this case, the nylon resin is a reinforced resin containing 10 to 35% by weight of the glass fiber relative to the total weight.

In addition, the raw material resin of the elastomer material is an ester resin such as polybutylene terephthalate (PBT) or polyethylene terephthalate (PET).

And, when injection molding the nylon resin or elastomer material on the surface of the surge tank and runner of the intake manifold and overmolding, the nylon resin or elastomer material, which is an injection molding material and an overmolding material, Using carbon dioxide or nitrogen instead of the blowing agent, the product is foamed at a foaming rate of 10 to 20% and overmolded.

It is noted that the foaming rate is defined by the following equation.

Foam Rate = (Po-P) / Po

Po denotes the molding density (g / cm 3) not subjected to foaming treatment, and P denotes the molding density (g / cm 3) of the foam.

In this way, in the present invention, by injecting nylon resin or elastomeric material into the surge tank and runner of the intake manifold by foam injection molding to manufacture the intake manifold, the noise generated in the intake manifold is greatly reduced. You can do it.

In order to prove the effect of the present invention, the transmission loss of sound was measured using a test apparatus as shown in FIG. 1, and the results of the measurement are shown in Table 1 below.

Here, a brief description of the configuration of the test apparatus shown in FIG.

That is, noise is produced in the speaker 11 in the anechoic chamber 10, which is transmitted to the outside through the test piece and the component 12.

At this time, the first microphone 13a is installed in the anechoic chamber 10, and the second microphone 13b is installed at a predetermined position close to the test piece and the component 12.

Thereafter, the amount of comparison noise of the microphones 13a and 13b is analyzed by the signal analyzer 14 so as to be determined by the control device 15.

As the transmission loss was measured using the test apparatus, before the transmission loss effect of the intake manifold component was measured, a circular specimen was manufactured to measure the transmission loss effect according to the material. The amount of transmission loss was measured, and the results of the measurement are also shown in Table 1 below.

As a specimen, Comparative Example 1 is a reinforced resin containing 35% by weight of glass fiber in polyamide 66, and Comparative Example 2 is an elastomeric material of a polybutylene terephthalate (PBT) resin system. Example 3 is a material in which polyamide 66 is foamed and molded with a foaming rate of 5% of a reinforced resin containing 35% by weight of glass fiber relative to the total weight, and Comparative Example 4 is an example of a polybutylene terephthalate (PBT) resin system. It is the material which foam-molded the stormer material at 5% of foaming ratios.

In addition, as a specimen, Example 1 is a material obtained by foam molding a reinforced resin containing 10% by weight of glass fiber in polyamide 66 at a foaming rate of 10%, and Example 2 is glass fiber in polyamide 66. Is a material formed by foaming a reinforced resin having a foaming rate of 15% based on 35% by weight of the total weight, and Example 3 is a foaming rate of 10% of an elastomeric material of a polybutylene terephthalate (PBT) resin system. It is a foam-molded material, and Example 4 is a material which foam-molded the elastomeric material of a polybutylene terephthalate (PBT) resin system at 15% of foaming ratio.

On the other hand, as the intake manifold component, Comparative Example 5 is a conventional plastic intake manifold without a cover, Comparative Example 6 is a conventional plastic intake manifold with a cover made of polypropylene, Comparative Examples 7 to 10 Are plastic intake manifolds each overmolded with the material of Comparative Examples 1-4.

In addition, as an intake manifold component, Examples 5-8 are the plastic intake manifold manufactured based on the manufacturing method of this invention overmolded with the material of Examples 1-4, respectively.

As a measurement result of the intake manifold component, as shown in Table 1 above, the existing plastic intake manifold (Comparative Example 6) with the cover is attached to the existing plastic intake manifold (Comparative Example 5) without the cover. It can be seen that it is advantageous in terms of the transmission loss of sound.

However, in the intake manifold (Comparative Examples 7 to 10 and Examples 5 to 8) in which the surge tank and the runner are overmolded with nylon resin or PBT-based elastomer material reinforced with glass fiber, the intake manifold (Comparative Example) Compared with 5 and 6), more improved results were obtained in terms of transmission loss of sound.

In particular, an intake manifold manufactured by overmolding the surge tank and the runner with a nylon resin or elastomeric material in a foam injection molding method so as to have a foaming ratio of 10 to 15% according to the manufacturing method of the present invention (Examples 5 to 5). The most remarkable improvement was obtained in 8).

As a result, according to the manufacturing method of the present invention, it becomes possible to manufacture the intake manifold which can greatly reduce the transmission noise.

In this manner, in the manufacturing method of the intake manifold of the present invention, the surge tank and the runner are overmolded with nylon resin or the elastomer material by foam injection molding of the nylon resin or the elastomer material into the surge tank and the runner. By doing so, it becomes possible to manufacture an intake manifold with excellent noise reduction effect.

As described above, according to the manufacturing method of the automobile intake manifold for noise reduction according to the present invention, in order to reduce the transmission noise in the upper part of the surge tank, which is the main noise of the intake manifold, the thickness of the surge tank Instead of the conventional noise reduction method to increase the volume or cover the surge tank with a cover, insert the surge tank and runner part of the intake manifold into the cavity in the mold, and then apply nylon resin or elastomer to the surface of the surge tank and runner. By overmolding the material by foam injection molding, the surge tank and the runner are manufactured in a dual structure of a dissimilar material, thereby providing the following effects.

1) Compared to the case where the cover is mounted on the surge tank, the manufacturing process is simple, but it does not cost any subsidiary materials, which is advantageous in terms of cost reduction.

2) As the subsidiary materials are eliminated, the weight reduction effect can be expected.

3) It is possible to manufacture an intake manifold with superior noise reduction effect compared to the existing intake manifold.

4) The conventional intake manifold has a problem that the foam pad is frequently released when used for a long time under high temperature conditions of the engine room, but this problem can be solved in the intake manifold according to the manufacturing method of the present invention.

5) It is very advantageous in terms of recycling because it uses a thermoplastic composite material instead of using a heterogeneous material (rubber foam material) used in the existing intake manifold.

Claims (2)

In the manufacturing method of the intake manifold for cars consisting of air inlet, surge tank and runner, After inserting the surge tank and the runner portion of the intake manifold into the cavity in the mold, the surge tank and the runner are overmolded by foam injection molding of nylon resin or elastomer material on the surfaces of the surge tank and the runner. Method for producing a car intake manifold for noise reduction, characterized in that the production of a dual structure of different materials. 2. The intake manifold for automobiles according to claim 1, wherein the nylon resin or elastomeric material is foamed so as to have a foaming rate of 10 to 20% by using carbon dioxide or nitrogen for foam injection molding. Fold manufacturing method.