JP3440128B2 - Combined silencer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite silencer mounted on an intake air duct or other gas flow duct of an internal combustion engine. 2. Description of the Related Art Conventionally, a resonance type silencer (resonator) is mounted to prevent noise from being released from the intake air duct and other gas flow ducts of an internal combustion engine to the outside air. The resonator is composed of a resonance chamber and a communication pipe, and the silencing characteristics are determined by the volume of the resonance chamber, the length and the inner diameter of the communication pipe, and the resonator has a high damping effect on a specific frequency range in the noise frequency distribution. Therefore, when it is desired to provide an attenuation effect over a wide frequency range, or when there are two or more sound pressure peaks of the noise frequency, a plurality of resonators are used. In this case, for example, for an automobile engine, when arranging in an engine room or the like, the occupied space may be narrow, so that the resonance chambers are grouped into one container, and the interior is partitioned to form each resonance chamber. I have. For example, it is the one disclosed in Japanese Utility Model Laid-Open No. 58-36666 (FIG. 3). [0003] Such a resonance type silencer often forms a container by injection molding of a synthetic resin. The container is divided into a main body portion and a lid portion, and is formed. I always do . [0004] By the way, each resonance chamber in the container needs to have a large volume or a small volume in order to have a wide range of noise reduction characteristics. If these resonance chambers are to be formed with only vertical walls in the container, those with a small volume will have a shape with a very narrow cross-sectional area and a relatively deep depth. In some cases, the shape of the chamber becomes so large that it does not become a resonance chamber that normally performs a resonance action. SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned disadvantages and makes the resonance chamber having a small volume an elongated shape.
Instead, a vertical wall in the depth direction is integrally formed on one or both of the main body and the lid that form the container, and a horizontal wall that is substantially perpendicular to the vertical wall is separately formed and fixed inside the container, Separate from the wall
A partition wall is formed by a combination with a lateral wall formed of a body . The inside of the container is divided into a plurality of resonance chambers by a partition wall composed of a vertical wall and a horizontal wall. By making the volumes different from each other and communicating with one gas flow duct through the communication pipe, resonance type silencers having different characteristics can be obtained, and the respective resonance chambers are integrated and compact . FIG. 1 shows an embodiment. The composite silencer 1 has a container 2 and a gas flow duct, in this example, an intake air duct 3 of an internal combustion engine, communicated with communication pipes 4, 5, and 6.
The container 2 is made of a synthetic resin, and is formed by joining the open ends of the main body 7 and the lid 8 at the joining edge 9 by vibration welding. Vertical walls 10 and 11 in the depth direction that partition the inside of the lid 8 are integrally formed,
Each of the three sections divided by vertical walls has communication pipes 4, 5,
6 are integrally formed. The main body 7 has a vertical wall 12 integrally formed therein, and its front end is joined to the vertical wall 10 of the lid 8. This joining may be performed by vibration welding simultaneously with the joining edge 9. The vertical wall 12 has a stepped portion 12a slightly below the tip and has a thick portion below the stepped portion 12a, and the thick portion has a slit-shaped gap portion 12b formed therein. It is in a state.
Furthermore, two opposing surfaces of the inner wall of the main body 7 (front-back direction of the paper surface)
Ribs 13 face the parallel coupling edge 9 to a position below the joint edge 9 is formed on the stepped portion 1 of the upper surface vertical wall 12 of the rib 13
It is connected to the upper surface of 2a to form a U-shaped flat surface. A partition wall 14 is provided in the main body 7. The partition wall body 14 is a square dish-shaped synthetic resin molded member, and three sides of a flange portion 14 a provided on a peripheral edge thereof are formed by the stepped portion 12.
a and the upper surfaces of the two ribs 13, 13. This fixing may be performed by using an adhesive, or may be incorporated in advance and fixed by vibration welding at the same time as the joint portion 9. The bottom wall of the partition wall 14 forms a horizontal wall 15. The four side walls 14b of the partition 14 constitute a part of the vertical wall. Note that the partition wall 14 may be a plate having no side wall. In this composite type silencer 1, the inside of the container 2 is
A resonance chamber 16 defined by 0 and 12;
A resonance chamber 17 defined by a partition wall 14 including a horizontal wall 15 and a vertical wall 11, and a resonance chamber 18 defined by a partition wall 14 including a vertical wall 11 and a horizontal wall 15 and a vertical wall 12.
And a resonance type silencer (resonator) including the communication pipes 4, 5, and 6, respectively. In this case, each of the resonance chambers 16, 17, and 18 has a different volume, and each has a specific silencing characteristic for different frequencies, so that it is effective for a wide range of noises. By integrating them, they can be stored in a compact space. By This resonance chamber 17 in the example most small volume provided with a transverse wall 15, rather like the shape of the resonance chamber is elongate as if extension of the communication pipe 7, and the expansion volume with respect to the communicating conduit 5 Can do it,
Sufficient resonance can be achieved. In addition, the resonance chamber 18 having the largest volume takes in the lower part of the lateral wall 15 so that the overall shape can be reduced without increasing the depth of the container 2 . The gap 12b of the vertical wall 12
Is a stealing of a thick part formed below in order to form the stepped portion 12a so as not to generate an undercut portion, which contributes to weight reduction. In the example shown in FIG. 1, the container 2 has a substantially rectangular parallelepiped shape. The volume may be retained. If necessary, reinforcing ribs may be provided on the vessel wall of the container to increase the rigidity. Further, the connecting line may be moved upward to form the lid into a plate shape, and the vertical wall may be formed into a divided shape provided only in the main body. In the example of FIG. 1, three resonance chambers are provided in the container. However, it is obvious that the number of chambers and the number of communication pipes are not limited to three. Further, since the lateral wall is formed separately, the main body and the lid of the container can be injection-molded using only simple upper and lower dies, so that the production is easy and the cost is reduced.

[Brief description of the drawings] FIG. 1 is a longitudinal sectional view of an embodiment. [Explanation of symbols] 2 containers 3 Gas flow duct 4, 5, 6 communicating pipe 7 Body 8 Lid 10, 11, 12 vertical wall 15 Side wall

Claims (1)

(57) [Claim 1] A plurality of resonance chambers are formed by providing a partition wall in a container formed by integrally connecting an opening end of a main body and a lid body,
In a composite type silencer made of synthetic resin in which each resonance chamber is connected to one gas flow duct with a respective communication pipe, a partition wall is formed in one or both of the main body and the lid in the depth direction in the depth direction. A composite silencer comprising a combination of a wall and a horizontal wall which is formed substantially as a separate body in a direction substantially perpendicular to the vertical wall and fixed in the container.