JPS5888453A - Structure of resonator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silencing structure for an intake system of an engine mounted on a vehicle such as an automobile, and particularly to a resonator structure.

In recent years, due to stricter external noise regulations for vehicles such as automobiles and higher requirements for internal noise levels, there has been an increasing need to further reduce intake noise generated from the intake system of the installed engine.

Originally, noise from the intake system is mainly in the low frequency range due to its characteristics as a low-pass filter, but measures such as increasing the capacity of the air cleaner, cool air ducts, and resonators have been adopted as countermeasures. Among these, the resonator is a very effective means for reducing noise at specific frequencies in the low frequency range.As shown in Figure 1, the resonator is a very effective means of reducing noise at specific frequencies. A structure has been adopted in which the end of the neck tube 4 of the resonator 3 is directly opened on the side wall surface of the resonator. However, with this structure, the air near the end of the neck pipe 4 is affected by the intake air flow in the intake nose 2, reducing the effective length of the neck pipe 4. On the other hand, in the engine room, space is Due to the above constraints, it is not possible to freely select the length of the neck pipe 4, which makes it difficult to obtain a sufficient amount of intake noise attenuation.The present invention solves the above problems and It is an object of the present invention to provide a resonator structure that can reliably obtain a sufficient intake noise attenuation effect despite space constraints within the resonator.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a partial sectional view of the resonator 3 according to the present invention attached to the air cleaner intake nose 2 of the intake system. The resonator 3 consists of a hollow resonance box 5 and a neck tube 4, each having a substantially rectangular parallelepiped shape.

A flange 5a having an inner diameter large enough to accommodate the neck tube 4 is provided at the center of the upper surface of the resonance box 5, and a screw hole 5c is provided above the opposing sides 5b, 5b. .

On the other hand, on the intake nose 2 of the air cleaner, seven flange 2a having an inner diameter equal to the outer diameter of the neck pipe 4 are provided downwardly and perpendicularly to the wall surface.

The neck tube 4 has an L-shape bent at a nearly right angle near its tip 4a, and the tip 4 & are inserted into the flange 2a so as to face each other and fixed by welding. The resonance box 5 has the other end of the neck tube 4 inserted into the flange 5a on its upper surface.
It is assembled with the transparent tube 4 by being fixed to a pair of mounting stays 2b, 2b vertically provided on the lower outer wall surface of the intake nose 2 with bolts 6 and screw holes 5C.

Since the resonator is configured in this way, not only is it not affected by the intake air flow in which the air near the neck tube tip 4a is swept away as in the conventional case, but the dynamic pressure of the intake air flow is always applied to the neck tube tip 4a. Therefore, this activates the piston movement of the air in the neck tube 4, and a sufficient amount of air noise reduction can be ensured. Figure 4 shows the engine's primary explosion frequency on the horizontal axis and the sound pressure level near the tip of the intake nose on the vertical axis.
The experimental results are plotted in the case of not adopting the method (dotted line), the case of the conventional technology (dotted line), and the case of the example (solid line), and the target frequency range is 60H2 to 80H.
It is shown that a sufficient effect was obtained in No. 2. Furthermore, since the length of the neck pipe 4 can be increased without sacrificing the space within the engine room, the degree of freedom in design when setting the main noise frequency and intake noise reduction amount is also expanded.

FIG. 3 shows a structure in which the distal end 4a of the neck tube is attached so as to face the downstream side of the intake air flow as indicated by the arrow, contrary to FIG. 2.

In this case, as in the case of Fig. 2, the intake air flow is
The same effect can be obtained since it does not adversely affect the internal air.

As explained above, according to Honkecho, sufficient intake noise reduction can be achieved by sacrificing the space inside the engine room (by arranging the tip of the neck tube of the resonator to face the engine's intake air flow). Excellent effects can be obtained that are easily achieved.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of an air cleaner showing the structure of a resonator according to the prior art, Fig. 2 is a sectional view of a resonator showing an embodiment, and Fig. 3 is a sectional view of a resonator showing another embodiment. FIG. 4 is a graph of actual results showing the effects of the embodiment. 2...Intake nose 3...Resonator-4
...Neck tube 4a...Neck tube tip 5...Resonance box Applicant: Toyota Motor Corporation Attorney Patent attorney Oka 1) Hidehiko Figure 1 Figure 2 F

Claims (1)

[Claims] A structure of a resonator characterized in that the tip of the neck pipe of the resonator is placed opposite or behind the intake air flow of the intake system of the engine.