KR19980036396A - Intake noise reduction device of car - Google Patents

Abstract

By the pulsation of the intake machine, an offset sound having an opposite phase difference is generated for the resonant sound having a certain frequency, thereby reducing the noise level and reducing the intake noise of the engine. To this end, the intake noise reduction device for automobiles according to the present invention is provided with a speaker 9 in the intake duct 4 that generates offset sounds having opposite phase differences with respect to resonant sounds having a predetermined frequency. This speaker is connected to the ECU, which receives an engine R.P.M signal from the R.P.M sensor 8 installed in the engine and generates an offset sound.

Description

Intake noise reduction device of car

1 is a configuration diagram showing the intake system of a typical vehicle.

2 is a block diagram showing an intake noise reduction device for a vehicle according to the present invention.

Figure 3 illustrates the state of action in this invention,

(A) is the frequency generated by the intake noise reduction device of this invention,

(B) is the frequency generated by the engine.

Explanation of symbols on the main parts of the drawings

4: intake duct 6: engine

7: Flywheel 8: R.P.M sensor

9: Speaker

Technical Field of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for reducing intake noise of a vehicle, and more particularly, to generate an offset sound having an opposite phase difference with respect to a booming sound generated from an engine, thereby reducing the intake noise of the engine. It relates to an abatement device.

[Private Technology]

An automobile engine, which is a representative example of an internal combustion engine, is usually composed of four cycles, and generates negative pressure by repetitive action of a piston that is lifted from a cylinder to inhale external air, and injects fuel into a combustion chamber in which the air is sucked to appropriately After the mixer is built, it is ignited to drive the engine.

Here, the intake air is introduced through the intake machine by opening the intake valve, which is opened once when the piston descends for the intake stroke.

As shown in FIG. 1, the air introduced into the intake machine is expanded and compressed in the intake passage 1 when the intake valve is closed, thereby generating intake noise due to intake pulsation.

These intake pulsations are synthesized in a surge tank 2, resulting in a pulsation noise in which the radiation of the noise is made. This noise is transmitted to the air cleaner 3 and repeats the behavior reflected from the connection and transmitted back to the surge tank 2. Subsequently, the noise transmitted to the air cleaner 3 is reflected at the inlet of the intake duct 4 and transmitted to the air cleaner 3.

These noises resonate with each other (interfere) to form standing waves in the intake passage 1, and vibrate by a frequency determined by the engine speed. In particular, the noise with certain frequency characteristics radiated at the inlet duct 4 suddenly increases through the space in the vehicle body or the vehicle compartment, producing resonance noise.

[Technical problem to be achieved]

In order to prevent the above-mentioned resonance noise, conventionally, a resonance chamber 5 of the air duct 4 before the air cleaner 3 is provided, but the resonance noise is a frequency component according to the RP M of the engine. Since this fluctuates, the effect is insignificant.

For this reason, in order to reduce resonance noise, efforts have been made to reduce resonance noise by canceling the resonance sound at a frequency causing resonance, thereby reducing the noise level.

The present invention is designed to reduce the resonant noise of the prior art, and generates an offset sound having an opposite phase difference to a resonant sound having a certain frequency due to the pulsation of the intake machine, thereby lowering the noise level and inspiring noise of the engine. To reduce the

[Configuration and Function of Invention]

As a means for realizing the above object, the intake noise reduction device of an automobile according to the present invention includes a surge tank communicating with an intake manifold of an engine, an intake passage communicating with the surge tank, and an air cleaner connected to the intake passage. And an intake duct for introducing outside air into the air cleaner.

Here, the intake duct is provided with a speaker for generating an offset sound having an opposite phase difference with respect to the resonance sound having a certain frequency. This speaker is connected to a control unit that receives an engine R.P.M signal and generates an offset sound.

According to this configuration, the intake noise reduction device generates an offset sound having a frequency of opposite phase difference to the noise having a constant frequency characteristic radiated from the intake duct inlet, thereby preventing the intake noise and resonance noise generated in the cabin do.

EXAMPLE

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

2 is an overall configuration diagram showing an intake noise reduction device for a vehicle according to the present invention.

In describing this embodiment, the same reference numerals are used for the configuration of this embodiment, which is the same as the drawings cited in the prior art, and will not be described again for clarity of explanation.

Reference numeral 6 in the drawings refers to the entire engine. The engine 6 forms a negative pressure by the lifting action of the piston lifting up and down in the cylinder, inhales outside air through the intake system, injects fuel into the combustion chamber to make an appropriate mixer, and then ignites it to drive the engine.

In addition, the driving force of the engine rotates the crankshaft, and transmits power through a clutch and a transmission installed in the flywheel 7 to drive the wheels.

As described above, the intake system of the engine includes a surge tank 2 communicating with an intake manifold of the engine, an intake passage 1 communicating with the surge tank, and an air cleaner 3 connected to the intake passage. ) And an air intake duct 4 that introduces outside air into the air cleaner.

Here, the intake noise reduction device according to this embodiment is to generate an offset sound having an opposite phase difference with respect to the resonance sound having a constant frequency generated in the intake duct 4, to lower the noise level and reduce the intake noise do.

To this end, the intake noise reduction device of this embodiment is provided with an RP M sensor 8 which detects the rotational speed of the flywheel 7 in the engine 6, and controls the signal of the RP M sensor 8 as a controller, for example. , To calculate the frequency of the resonant sound according to the RP M of the engine to the electronic control unit (ECU), and through the speaker 9 installed in the air duct (4) to generate an offset sound having a phase difference opposite to the resonant frequency Let's do it.

In this case, the frequency of the resonance sound generated in the engine is shown as 200 Hz, assuming that the maximum rotational speed of the engine is 6,000 R. P. M. Therefore, the frequency of the offset sound is in the range of 0 to 200 Hz.

3 illustrates the operation of the intake noise reduction device according to this embodiment, (a) is the frequency of the offset sound generated by this embodiment, and (b) is the frequency of the resonance sound generated by the engine. .

As can be seen from the figure, the canceling sound and the resonance sound coincide to have opposite phase differences with each other, thereby substantially eliminating the occurrence of the resonance noise.

[Effects of the Invention]

As can be seen through the embodiment described above. The intake noise reduction device for automobiles according to the present invention has the effect of canceling the intake pulsation generated in the intake machine and the resonance sound generated in the intake duct, thereby reducing the noise level and reducing the intake noise of the engine.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and any person having ordinary knowledge in the field of the present invention can make various changes without departing from the gist of the present invention claimed in the claims. Would be possible.

Claims (3)

An intake system of a vehicle including a surge tank communicating with an intake manifold of an engine, an intake passage communicating with the surge tank, an air cleaner connected to the intake passage, and an intake duct for introducing outside air into the air cleaner. In And a control unit for receiving the signal of the engine RP M and generating an offset sound having an opposite phase difference with respect to the resonance sound generated in the intake duct, and a speaker for generating an offset sound in the intake duct by the control unit. Intake noise reduction device for automobiles. The intake noise reduction device of a vehicle according to claim 1, wherein the control unit is an ECU which receives a signal from an R.P.M sensor installed in an engine and generates an offset sound. The intake noise reduction device of a vehicle according to claim 1, wherein the controller generates an offset sound of 0 to 200 Hz.