JPH02181063A - Intake manifold for internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce transmitting sound run through the wall of an intake manifold due to intake pulsation and combustion noise by forming the wall on the position of generation of transmitting sound more massive than the wall of another position, in an intake manifold made of synthetic resin. CONSTITUTION:A plurality of branch pipes 2 are mutually independently and in parallel projectingly provided on the main body 1 of an intake manifold made of synthetic resin. Flange parts 3 for fitting to a cylinder head are formed on outer circumferences of opening ends of respective branch pipes 2. Further, an intake port 6 for air-fuel mixture is formed on the intake manifold main body 1. In this case, the wall on the position of generation of transmitting sound in the manifold main body 1, namely, usually the wall on the side provided with the intake port 6 is formed more massive than the wall of another position. For example, thickness W1 of the wall 1A on the side provided with the intake port 6 is formed larger than the basic thickness W2 of another position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake manifold for an internal combustion engine, and more particularly to an improvement of an intake manifold entirely molded from synthetic resin.

[Conventional technology]

Traditionally, most intake manifolds for internal combustion engines have been made of aluminum for the purpose of reducing weight, but aluminum is easier to form, has lower material costs, and is even lighter than aluminum. Due to these advantages, various intake manifolds made of synthetic resin have recently been proposed.

[Problem that the invention seeks to solve]

This synthetic resin intake manifold has excellent damping properties due to its material, so compared to aluminum intake manifolds, vibration-transmitted noise generated by internal combustion engine combustion, etc., enters the intake manifold through the cylinder head. However, it was found that the results showed very good results in reducing the radiated sound emitted from the surface.

However, as a result, intake pulsation and combustion noise, which had been masked by the radiated sound and were not noticeable, now penetrate through the wall of the intake manifold, and this transmitted noise has become a new problem.

The present invention was made in order to solve the problem of transmitted sound caused by such a synthetic resin intake manifold. An intake manifold for an internal combustion engine is characterized in that the mass of the intake manifold is larger than the wall surface of the part.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in FIGS. 1 to 8. Note that FIG. 1 is a front view of a synthetic resin intake manifold, and FIGS. 2 to 8 are side views of different embodiments with parts cut away showing essential parts of the present invention.

In Fig. 1, reference numeral 1 denotes an intake manifold main body made of synthetic resin, and a plurality of branch pipes 2.2 are provided in this intake manifold main body 1 and protrude independently and in parallel. A flange portion 3 for attachment to a cylinder head (not shown) is formed on the outer periphery of the open end.

Reference numeral 4 denotes a bridge connecting each of the flange parts 3, 3, which is a structure in which the interior is equally hollowed out 4a, and is integrally connected by this bridge 4.

5 is a bolt insertion hole formed in each flange portion 3, and 6 is an air-fuel mixture intake boat formed in the manifold body 1. In addition, 7 in the figure is EGR (Exhaust
This is a mounting hole for a valve that controls the amount of recirculation in the exhaust gas recirculation system (exhaust gas recirculation device), and 8 is a mounting hole for a fixed resistor for preheating the air-fuel mixture.

In such an intake manifold made of synthetic resin, in the present invention, the wall surface of the part of the intake manifold where transmitted sound is generated;
In other words, normally the wall surface on the side where the intake boat 6 is installed,
It is designed to have a larger mass than the wall surfaces of other parts to reduce the transmitted noise from the wall surfaces.

That is, this will be explained with reference to the embodiments shown in FIGS. 2 to 8. In the example shown in FIG. 2, the thickness W1 of the wall surface IA on the side where the intake boat 6 is installed is Thickness W2
The wall surface IA shown in FIG. The central part 9 of the board is foamed.

Furthermore, in the case shown in FIG. 4, the intake cocoon body 1 is formed entirely with a basic wall thickness W2, and a sound absorbing plate 10 is attached to the inner surface of the wall surface IA on the side where the intake boat 6 is installed. On the contrary, the one shown in FIG. 5 has sound absorbing plates 10 mounted on the outer surface of the wall surface IA, and 102 in the above figure is a reinforcing plate.

In the embodiment shown in FIG. 6, as in the embodiment shown in FIGS. 4 and 5, the intake manifold main body 1 is formed entirely with a basic thickness W2, and the inner surface of the wall surface IA is A sound insulating plate 11 such as an iron plate is attached with a gap 11a between the two, and the one shown in FIG. 7, on the contrary,
A sound insulating plate 11 such as an iron plate is attached to the outer surface of the wall surface IA with a gap 11a interposed therebetween.

Furthermore, what is shown in FIG. 8 is another embodiment, in which a hole 12 is formed in the wall surface IA, and a separate part with excellent sound insulation is inserted into the hole 12, for example, made of aluminum, high specific gravity resin, iron or ceramic. A cover 13 is attached.

Since the wall IA of the intake manifold is made to have a larger mass than the walls of other parts, even if vibration-transmitted noise generated by combustion in the internal combustion engine enters the intake manifold through the cylinder head, Noise transmitted through the wall IA is reduced.

〔Effect of the invention〕

As described above, in the synthetic resin intake manifold according to the present invention, the wall surface of the part of the intake manifold where transmitted sound is generated has a larger mass than the wall surface of other parts.
Due to the excellent damping properties of synthetic resin, even if the vibration-transmitted noise generated by combustion in an internal combustion engine enters the intake manifold through the cylinder head, the radiated sound emitted from the surface of the cylinder head can be reduced. Another advantage is that the noise transmitted by intake pulsation and combustion noise that penetrates the wall of the intake manifold is also reduced.

[Brief explanation of the drawing]

FIG. 1 is a front view of a synthetic resin intake manifold according to the present invention, and FIGS. 2 to 8 are partially cutaway side views showing the main parts of different embodiments of the present invention. . 1...Intake manifold body, IA...Wall surface,
2... Branch pipe, 6... Intake boat. N Procedural amendment (method) 1999!1-May 1411

Claims (1)

[Claims] An intake manifold for an internal combustion engine, characterized in that the wall surface of the synthetic resin intake manifold in a transmitted sound generating area has a larger mass than the wall surface of other parts.