KR20100008448A - A resonator structure for a vehicle's muffler - Google Patents

Abstract

PURPOSE: A variable resonator structure of a vehicle silencer is provided to effectively reduce the exhausting sound according to rpm of an engine because the reducing goal frequency of resonator is consecutively changed according to the noise frequency component changed according to rpm of an engine. CONSTITUTION: A variable resonator structure of a vehicle silencer comprises a resonator(30), a resonator neck(31), and an area changer(40). The resonator is formed at both sides of an exhaust pipe(20) installed within a silencer body(10). The resonator neck is formed in the outer circumference of the exhaust pipe. The area changer is installed in the resonator neck and changes the area of the resonator neck according to the RPM of an engine and the exhaust pressure.

Description

A resonator structure for a vehicle's muffler}

The present invention relates to a variable resonator structure of an automobile muffler for continuously reducing intake and exhaust machine discharge noise according to engine operating conditions. More particularly, the present invention relates to a variable resonator structure of an automobile silencer. It is about making the target frequency of the variable variable.

In the related art, a resonator type silencer of an automobile is effective only for a specific frequency noise attenuation, and cannot exert an effect on a noise component that changes according to a change in driving conditions, that is, an engine speed (RPM).

In order to overcome this, the present inventors have a variable valve of the muffler formed so that the exhaust gas inlet and the exhaust gas outlet are connected to both sides of the housing, respectively, and the amount of opening and closing is adjusted according to the flow rate of the exhaust gas in the middle of the exhaust gas outlet. The upper door and the lower door are fixed to the front upper side and the lower side of the exhaust gas outlet by a hinge, the upper door and the lower door is formed on both sides of the outer periphery of the hinge hole outward and inwardly extending the predetermined section, A variable valve of the muffler (opened patent application No. 10-2006-0058261) characterized in that a return spring for providing an elastic force to the upper door and the lower door is mounted in the middle of the hinge shaft into which the hinge hole is fitted; A variable muffler for a vehicle that adjusts the back pressure by varying the exhaust flow path of the exhaust gas generated by combustion from the combustion chamber of the engine, and is connected to the exhaust pipes at the front and the rear, and is equipped with a plurality of exhaust walls having a plurality of partition walls installed therein. A housing having a hollow part divided into a seal | combine, and a connection tube mounted by a partition wall inside the housing to connect the exhaust chamber of the multistage, and mounted between the exhaust pipe outlet end of the front side and the inner wall of the housing according to the exhaust pressure. A variable muffler for a vehicle (Publication Patent No. 10-2007-0032589) has been proposed, which includes a variable exhaust means that operates by varying the degree of opening of the outlet end of the front exhaust pipe.

In addition, the present applicant is a technology for changing the volume of the resonator in conjunction with the engine operating conditions, the variable volume silencer structure (Patent No. 10-2006-0058285) and the variable resonator (Patent No. 10-2005-0042891), and A variable volume resonator (Patent No. 10-2004-0033441) has been proposed, and a technique for changing the volume of such a resonator in conjunction with engine operating conditions has been described in some foreign literature (for example, SAE 2008-01). -0896, Tuned Silencer Using Adaptive Variable Volume Resonator)

On the other hand, Fig. 1A shows a longitudinal cross-sectional view of a valve closing mode of a conventional variable silencer, and Fig. 1B shows a longitudinal cross-sectional view of a valve opening mode of a conventional variable silencer.

However, the conventional variable silencer illustrated in FIGS. 1A and 1B is configured to be variable through opening and closing of a dual mode valve, and thus has a disadvantage in that it can be effective only in two specific conditions.

That is, in the conventional variable silencer, the dual mode valve has only a simple function to be opened when the flow rate is large according to the spring force, and only reflects two conditions when the valve is opened and closed, and continuously changes the engine speed (RPM). It is virtually impossible to see an effect on the continuous frequencies of certain noise components that change continuously.

The present invention has been made in view of the above-described conventional problems, and the object thereof is to provide a variable resonator structure of a vehicle silencer such that the target frequency can be continuously changed in accordance with the main noise component continuously changing according to the engine speed. It is in

In the variable resonator structure of the automobile silencer of the present invention for achieving the above object, the effective effective area (S) of the resonator neck is continuously changed in conjunction with the engine speed so that the attenuation target frequency of the resonator is linked with the engine engine. By being able to vary continuously, it is possible to reduce the discharge sound continuously changing in accordance with the engine speed change.

That is, the variable resonator structure of the vehicle silencer of the present invention is provided with a resonator on both sides of the exhaust pipe installed inside the silencer body, a resonator neck on the outer periphery of the exhaust pipe, the engine speed and exhaust pressure on the resonator neck) As a result, an area changer is installed to change the area of the neck of the resonator.

In the present invention, the area changer includes: a moving body for adjusting the length of the resonator neck while moving in the longitudinal direction of the exhaust pipe according to the exhaust pressure; It may be configured as a spring for elastically supporting the moving body.

In addition, a projection projecting inwardly of the exhaust pipe may be provided inside the moving body of the area changer so that the pressure of the exhaust gas, which changes according to the number of engine revolutions, may act on the moving body. May be formed as an inclined surface to prevent the generation of additional flow noise due to the movement of the moving body.

According to the present invention, since the attenuation target frequency of the resonator is continuously changed in accordance with the noise frequency component continuously changing according to the engine speed, the exhaust discharge sound can be effectively attenuated according to the engine speed.

Hereinafter, the specific technical details of the present invention will be described in more detail with reference to the accompanying drawings.

2 is a view illustrating a change in exhaust discharge sound frequency according to a change in engine speed.

As shown in FIG. 2, the frequency of the main noise component is changed according to the engine speed in the case of the vehicle exhaust discharge sound.

3 shows a schematic of a resonator for a particular frequency attenuation.

In general, a resonator for noise reduction at a specific frequency can be illustrated as shown in the schematic diagram of FIG. 3, by the height (t), the area (S), and the resonator volume (V) of the neck constituting the resonator. The target frequency f _target , which is effective for noise attenuation, is determined by the following equation.

t: neck height

S: neck cross section

V: Resonator Volume

c: sound speed

4 is a longitudinal cross-sectional view of a silencer equipped with a resonator in order to attenuate a specific frequency in a conventional vehicle silencer.

5 is a longitudinal sectional view of one embodiment of the present invention.

As shown in FIG. 5, the variable resonator structure of the vehicle silencer according to the present invention provides the resonator 30 on both sides of the exhaust pipe 20 installed inside the silencer main body 10, and the resonator neck on the outer circumference of the exhaust pipe 20. (31) is provided, and the resonator neck (31) is provided with an area changer (40) for changing the area of the resonator neck (31) in accordance with the engine speed and the exhaust pressure.

In the illustrated embodiment, the area changer 40 includes: a moving body 41 for adjusting the length of the resonator neck 31 while moving in the longitudinal direction of the exhaust pipe 20 according to the exhaust pressure; It consists of the spring 42 which elastically supports the moving body 41. FIG.

In the present invention configured as described above, the exhaust pressure and the flow rate passing through the exhaust pipe 30 installed inside the muffler main body 10 are changed according to the engine speed, and thus the moving body 41 of the area changer 40 is changed. ) Is moved so that the length and effective area of the resonator neck 31 is changed, so that the target exhaust emission attenuation frequency of the resonator 30 is changed.

That is, in the present invention, the attenuation target frequency f _target is determined by Expression 2-1, and the cross-sectional area S of the resonator neck is determined by Expression 2-2.

t: height of the resonator neck

S: cross section of the resonator neck

V: Resonator Volume

c: sound speed

W: Circumferential effective width of the resonator neck

L: Axial effective length of the resonator neck

6 is a main longitudinal cross-sectional view of one embodiment of the present invention.

6, the protrusion 41a protrudes inwardly of the exhaust pipe 20 inside the moving body 41 of the area changer 40 installed in the resonator neck 31 of the exhaust pipe 20. The pressure of the exhaust gas, which changes according to the engine speed, may act on the movable body 41, and the elastic restoring force of the spring 42 elastically supporting the movable body 41 and the pressure of the exhaust gas pressure acting on the movable body 41 are provided. The position of the movable body 41 is determined by the balance of the forces.

Therefore, the moving body 41 moves forward or backward in the longitudinal direction of the exhaust pipe 20 according to the pressure of the exhaust gas passing through the exhaust pipe 20, and accordingly, the axial effective length L of the resonator neck 31. Is continuously changed, and at a high rotational speed at which the exhaust gas pressure is relatively high, the amount of advancement of the moving body 41 increases, so that the axial effective length L of the resonator neck 31 becomes long, and the exhaust gas pressure is relatively high. At low and low rotational speeds, the amount of retraction caused by the spring 42 elastic force becomes large, and the axial effective length L of the fpsonator neck 31 is shortened.

In the illustrated embodiment, the front end surface of the protrusion 41a provided inside the movable body 41 is formed as the inclined surface 41b to prevent the occurrence of additional flow noise due to the movement of the movable body 41.

Meanwhile, the illustrated embodiment is a detailed structure for continuously changing the area of the resonator neck in conjunction with the engine speed to continuously change the main noise attenuation frequency of the resonator. In the present invention, the structure for changing the cross-sectional area of the resonator neck is the effective area (S) due to the rotational movement of the area changer. It is also possible to apply to the change of, and active control by the engine speed signal for position control in the axial direction (or rotation direction) is also possible.

In addition, the continuous variable resonator structure of the present invention can be applied to the intake machine as well.

7 is a graph showing a change in the main noise frequency of the exhaust discharge sound according to the engine speed, Figure 8 is a graph showing a change in the resonator target frequency according to the present invention.

As shown in Figs. 7 and 8, by changing the axial effective length L of the resonator neck 31 in accordance with the change of the engine speed, the attenuation effect of the main noise component can be obtained.

On the other hand, the continuous variable resonator of the present invention can be similarly applied to an intake machine.

The present invention described above is not limited to the above-described embodiments and drawings, and various permutations, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those who have

Figure 1a is a longitudinal cross-sectional view of the valve closing mode of a conventional variable silencer

Figure 1b is a longitudinal sectional view of the valve opening mode of the conventional variable silencer

3 is a schematic diagram of a resonator for a specific frequency attenuation

4 is a longitudinal sectional view of a silencer equipped with a resonator to attenuate a specific frequency in a conventional vehicle silencer

5 is a longitudinal sectional view of one embodiment of the present invention;

6 is a longitudinal sectional view showing main parts of one embodiment of the present invention;

7 is a graph showing the change of the main noise frequency of the exhaust discharge sound according to the engine speed

8 is a graph showing a change in the resonator target frequency according to the present invention

<Explanation of Signs of Major Parts of Drawings>

10: silencer body 20: exhaust pipe

30: Resonator 31: Resonator Neck

40: area changer 41: moving body

41a: protrusion 41b: inclined surface

42: spring

Claims (4)

Resonators are provided on both sides of the exhaust pipe installed inside the muffler main body, a resonator neck is provided on the outer periphery of the exhaust pipe, and a resonator neck is used to change the area of the resonator neck according to the engine speed and exhaust pressure. A variable resonator structure for an automobile silencer, which is installed. The method of claim 1, wherein the area changer comprises: a moving body for adjusting the length of the resonator neck while moving in the longitudinal direction of the exhaust pipe according to the exhaust pressure; Variable resonator structure of the vehicle silencer, characterized in that consisting of; a spring for elastically supporting the moving body. The variable resonator structure of an automobile silencer according to claim 2, wherein a protrusion projecting inwardly of the exhaust pipe is provided inside the moving body of the area changer so that the pressure of the exhaust gas, which changes according to the engine speed, can act on the moving body. . 4. The variable resonator structure of an automobile silencer according to claim 3, wherein the front end surface of the protrusion provided inside the movable body is formed as an inclined surface to prevent the occurrence of additional flow noise due to the movement of the movable body.

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