JPS58124057A - Suction air resonator - Google Patents

Abstract

PURPOSE:To widen the width of the damping characteristics of the suction air resonator with respect to the frequency thereof by a method wherein a resonance chamber is divided and a bulkhead supported elastically is provided. CONSTITUTION:The suction air resonator 12 is connected to the nozzle 10 of the air cleaner constituting the end part of the suction pipe of an engine while the suction air resonator 12 is divided into an upper chamber 20 and a lower chamber 22 by a diaphragm 18. The diaphragm 18 is equipped with a disc-shaped central part 24 and a concentric wavy outer peripheral part 26 while the central part 24 is supported elastically by the outer peripheral part 26 so as to be vibratable. An adjusting piece 28 determining the vibrating mass of the diaphragm 18 is secured to the central part of said diaphragm 18.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to
(Improved intake resonator that absorbs noise by resonance)
This is related to this.

Due to the pumping action of histones, air is intermittently sucked into the cylinders of the engine, and as a result, intake noise with a frequency of 1+V, t(1), which is related to the engine's rotational speed, Connect the piping to 11ti;
be attacked. For this reason, an intake resonator is provided which has a resonant cavity bonded to the engine's intake pipe (6iH) and attenuates the intake noise emitted through the intake pipe by the resonance absorbing action of the resonant cavity.However, According to such a conventional intake resonator, in order to improve its damping performance, the volume of the resonant chamber must be increased, while the volume for the intake resonator in the engine room where the engine and its intake piping are housed is small. is not sufficiently tolerated, and therefore sufficient resonance absorption characteristics for attenuating intake noise cannot necessarily be obtained.

With the above circumstances in mind, the inventors of the present invention have repeatedly produced various prototypes, and have found that by dividing the resonant chamber with vibrating partition walls, the damping characteristics of intake noise can be significantly improved without increasing the volume of the resonant chamber. I found out the truth. The present invention has been made based on the above findings.

That is, the gist of the present invention is to provide an intake resonator that includes a resonant chamber connected to the intake piping of an engine and that resonates and absorbs the intake noise of the intake piping system. 1. Placed inside the Naruko room,
In addition, the partition wall is elastically supported so as to be able to vibrate.

1 below, A'N based on the drawings showing one embodiment of the present invention.
Explain in detail.

In FIG. 1, the cylindrical nose part 10 of the air cleaner, which forms the tip of the engine's intake pipe, has a 1117'<
j resonator 12 is connected. Intake resonator 1
2 consists of a short cylindrical main body 14 consisting of an upper container 11 and a lower container 13, and a connecting pipe section 16 protruding from the end surface of the main body 14.
It is connected to the nose part 10 through. In the resonant chamber, a circular diaphragm 18 forming a partition wall is connected to the upper container 11.
and an upper chamber 20 which is sandwiched by the upper container 13 and thereby communicates with the nose portion 10 and a volume I than the upper chamber 20:
It is divided into a fairly small sealed lower chamber 22 and a lower chamber 22. The rear 7 ram 18 has a disc-shaped central part 2.
1 and a concentric wave-like outer peripheral part 26, and is elastically supported by the central part or the outer peripheral part so as to be able to vibrate. As shown in FIG. 2, an adjustment piece 28 is fixed to the center of the diaphragm 18 to determine the vibrating mass of the diaphragm 18.

When an engine equipped with an intake pipe to which the intake resonator 12 configured as described above is attached is operated,
It has a frequency component corresponding to the rotational speed of the engine, and the intake noise of the intake piping system that is released to the outside through the nose portion 10 is suppressed very effectively compared to the conventional case. The reason why such an effect is obtained is considered to be due to the following reasons.

In other words, in a conventional intake resonator in which the wall surface of the resonant chamber is made of a highly rigid material, the resonant frequency fo is calculated by the following formula; where C is the speed of sound, ■ is the volume of the resonant chamber, and e is The length of the connecting pipe section, S is the cross-sectional area of the connecting pipe; and is expressed by the amount of attenuation due to resonance absorption.

(Unit: decibel), as shown by the solid line in Figure 3, is expressed by the following formula; where ρ0 is the density of the medium, Co is the acoustic conductivity of the resonant chamber, and oI is the angular velocity of the sound wave (intake noise). It has the property represented by;

However, the intake noise radiated to the outside through the intake pipe is mainly composed of frequency components related to the engine speed, and the frequency of the intake noise changes as the engine rotates, so the solid line in Figure 3 It is difficult to attenuate intake noise that can vary over a wide range of frequency components using a conventional intake resonator that has an attenuation q1 characteristic with a sharp peak as shown in Figure 1, except by increasing the capacity of the resonance chamber. There it was.

On the other hand, according to the intake resonator 12, that! (The Naraku chamber is divided by diaphragm 18 and jjH1g
1-chamber 2, which occupies the majority of the empty space and communicates with the nose portion 10;
The diaphragm 18, which forms part of the inner wall surface of the 1-chamber 20, is elastically supported and vibrates. Therefore, together with the vibration characteristics of the diaphragm 18, a wide range of attenuation characteristics with respect to frequency can be obtained, as shown by the dotted line in FIG. As a result, the intake noise that can vary over a wide range of frequency components can be effectively absorbed by the intake resonator 12 as a whole without increasing the volume of the intake resonator 12.

Here, the attenuation characteristic can be changed as appropriate by changing the weight of the adjusting piece 28, the elastic force of the outer periphery of the diaphragm 18, etc. It has the advantage that it can be applied to various types of engines by only changing.

Further, since the diaphragm 18 is provided to be able to vibrate, the lower container 13 has a function of preventing intake noise from being transmitted to the outside through the diaphragm 18.

Next, another embodiment of the present invention will be described. In addition, what parts of the following explanation have in common with the previous explanation? A through hole 32 with a small W number is formed.

Therefore, the lower chamber 22 is communicated with the upper chamber 20 through the through hole 32, and the lower chamber 22 itself resonates and absorbs the intake noise that reaches the upper chamber 20. It is possible to fit it into 11-.

I11 Although the embodiment of the present invention has been described based on the drawings, the present invention can also be applied to other aspects.

For example, 1f is applied to the same model of engine.
If the damping characteristic of the air resonator 12 with respect to the frequency is sufficient to be constant, the quality of the central portion 24 of the diaphragm 18 may include the mass of the adjustment piece 28, and the adjustment piece 28 may be removed. be.

The number, diameter, and position of the intake resonator 12 can be changed as appropriate depending on the type of engine to which the intake resonator 12 is applied.

As described in detail above, since the intake resonator of the present invention is provided with a supported bulkhead, the frequency range of the damping characteristic of the intake resonator is widened, and the intake air radiated to the outside through the intake pipe of the engine is increased. Noise is effectively attenuated without increasing the volume of the intake resonator.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the configuration of an embodiment of the present invention. FIG. 2 is a sectional view taken along line I-1 in FIG. 1. FIG. 3 is a diagram explaining the characteristics of FIG. 1. FIG. 4 is a diagram corresponding to FIG. 2 explaining another embodiment of the present invention. 10: Nose part (intake piping) 12: Intake resonator 18: Diaphragm (partition wall) Applicant Toyota Motor Corporation Part'3 Figure 4-1

Claims (1)

[Claims] In an intake resonator that includes a resonant chamber connected to the intake piping of an engine and that resonates and absorbs intake noise in the intake piping system, 1. An intake resonator, which is disposed indoors and is capable of vibrating by elastically supporting a partition wall.