JPH10339128A - Exhaust muffler integrating valve for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust muffler including a valve for an automobile in which valve opening action timing can be stably obtained without having effects of irregularity or temperature change, and in which silencing mode change can be achieved by valve opening/closing action of high responsiveness. SOLUTION: An exhaust pressure sensitive valve A is provided with a valve main body 1 disposed on a second exhaust tube 19, opened in a muffler at one end part, and opened in open air or in the muffler at the other end part, at an opened end of it in the muffler, and a valve shaft 2 to rotatably support the valve main body 1 to open/close it, the gravity action center G of the valve main body 1 is set at a position apart from the valve shaft 2 in a gas low line direction to obtain valve closing direction moment, and an exhaust gas pressure action center P acting on the valve main body 1 is set at a position where valve opening direction moment can be obtained by exhaust pressure, thereby need of a spring can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of an exhaust muffler with a built-in valve for an automobile in which an exhaust gas pressure sensitive valve which opens and closes in accordance with an increase and decrease of the exhaust gas pressure due to static pressure and dynamic pressure is provided in the muffler. Belong.

[0002]

2. Description of the Related Art In recent years, there has been an increasing number of cases in which a switching valve is provided in a muffler for the purpose of improving low pressure loss at a high engine speed and improving noise reduction at a low engine speed (Japanese Patent Laid-Open No. 2-81911). Etc.).

[0003] This valve is closed when the engine speed is low, and the exhaust gas circulates optimally in the muffler to obtain a large volume. However, as the engine speed increases, the pressure in the valve front chamber increases, and the valve opens. Operation and low pressure loss.

Normally, as shown in FIG. 6, the valve is attached to the rear end of the inner tube of the muffler (downstream of the exhaust gas flow) and is opened to keep the pressure in the valve front chamber constant. .

[0005]

However, the conventional exhaust muffler with a built-in valve has the following problems.

(1) Although a spring is used to make the valve closed, the spring force changes with temperature due to the characteristics of the spring.

(2) The opening operation is performed so as to keep the pressure in the valve front chamber constant. A large volume reduction is obtained when the valve is closed, and then the pressure loss gradually decreases as the valve opening increases. Control.

[0008] It is not possible to respond to the demand to obtain a high acceleration by fully opening the valve from a valve closed state where a large volume can be obtained.

(3) A large variation occurs in the engine speed at which the valve starts to open due to spring force or bearing loss.

It is an object of the present invention to provide an exhaust muffler with a built-in valve for a vehicle which can stably obtain a valve opening operation timing without being affected by variations and temperature changes and achieve a silencing mode switching by a high response valve opening / closing operation. To provide.

[0011]

[Means for Solving the Problems]

According to a first aspect of the present invention, there is provided an automobile valve in which an exhaust gas pressure sensitive valve that opens and closes in accordance with an increase and decrease of an exhaust gas pressure due to static pressure and dynamic pressure is provided in a muffler. In the built-in exhaust muffler, the exhaust gas pressure sensitive valve has a valve body disposed at a muffler opening end of an exhaust tube having one end opened in the muffler and the other end opened in the outside air or the muffler. A valve shaft that supports the valve body so that the valve body can be opened and closed, and the gravitational action point of the valve body is set at a position away from the valve shaft in the streamline direction of the gas flow so as to obtain a valve closing moment. The exhaust gas pressure acting central point acting on the valve body is set at a position where the valve opening direction moment can be obtained by the exhaust gas pressure.

According to a second aspect of the present invention, there is provided an exhaust muffler with a built-in valve for an automobile according to the first aspect, wherein a valve body is inclined at an opening end of the exhaust tube inside the muffler. The exhaust gas pressure acting center point is set to a position where a moment in the valve opening direction can be obtained by the exhaust gas pressure.

According to a third aspect of the present invention, there is provided an exhaust muffler with a built-in valve for an automobile according to the first or second aspect, wherein the valve shaft is offset to a position higher than a gravity action point. By doing so, the exhaust gas pressure action center point is set to a position where the valve opening direction moment can be obtained by the exhaust gas pressure.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

 Embodiment 1 First, the configuration will be described.

The first embodiment corresponds to the first and second aspects of the present invention.

FIG. 1 is an exploded perspective view showing an exhaust gas pressure sensitive valve of an exhaust muffler with a built-in automotive valve according to a first embodiment.
FIG. 2 is a sectional view showing an exhaust gas pressure sensitive valve of the exhaust muffler with a built-in automotive valve according to the first embodiment. FIG. 3 is an overall sectional view showing the exhaust muffler with a built-in automotive valve of the first embodiment.

In FIG. 3, A is an exhaust gas pressure sensitive valve, 10 is a muffler side plate, 11 is a front end plate, 12 is a rear end plate,
13 is a first baffle plate, 14 is a second baffle plate, 15 is an exhaust input tube, 16 is a first tube,
17 is a second tube, 18 is a first exhaust tube, 19 is a second exhaust tube, 20 is a first chamber, 21 is a second chamber, 22
Is the third room.

The exhaust gas pressure sensitive valve A is a valve that opens and closes in accordance with the increase and decrease of the exhaust gas pressure due to static pressure and dynamic pressure, and is a second exhaust tube 19 that communicates the second chamber 21 with the outside air.
Is arranged at the opening end in the muffler.

The exhaust input tube 15 is connected to an exhaust tube from the engine, and introduces exhaust gas into the second chamber 21.

The first tube 16 is provided on the second baffle plate 14, and has one end open to the second chamber 21 and the other end open to the third chamber 22.

The second tube 17 is provided on the first baffle plate 13, and has one end opened to the first chamber 20 and the other end opened to the second chamber 21.

The first exhaust tube 18 includes a first baffle plate 13, a second baffle plate 14, and a rear end plate 1.
2, one end is open to the first chamber 20, and the other end is open to the outside air.

The second exhaust tube 19 is provided on the second baffle plate 14 and the rear end plate 12, an exhaust gas pressure sensitive valve A is provided at one end, and the other end is open to the outside air. When the exhaust gas pressure sensitive valve A is opened, the second chamber 21 is opened.
Communicates with the outside air.

When the exhaust gas pressure sensitive valve A is in the closed state, the first chamber 20 and the second chamber 21 are expansion chambers, the third chamber 22 is a resonator chamber, and exhaust gas is discharged only from the first exhaust tube 18 to the outside. Is discharged. When the exhaust gas pressure sensitive valve A is open, the exhaust gas is discharged to the outside by the first exhaust tube 18 and the second exhaust tube 19.

1 and 2, A is an exhaust gas pressure sensitive valve, 1 is a valve body, 2 is a valve shaft, and 19 is a second valve.
It is an exhaust tube.

The valve body 1 has a second exhaust tube 1 having one end opening into the muffler and the other end opening to the outside air.
9 at the opening end in the muffler.

The valve shaft 2 is a shaft for supporting the valve body 1 so as to be capable of opening and closing, and is set horizontally at an intermediate position of the second exhaust tube 19 at a position upstream of the valve body 1. The valve shaft 2 has a pin hole 1b formed in a pin bracket 1a formed integrally with the valve body 1.
And a pin hole 19b opened in a pin bracket portion 19a formed integrally with the second exhaust tube 19, and the pin 2a is inserted into and fixed to the pin bracket portion 19a to prevent the pin 2a from coming off.

The gravitational action point G of the valve body 1 is shown in FIG.
As shown in the figure, the valve shaft 2 is set at a position upstream of the valve body 1, that is, at a position distant from the valve shaft 2 in the streamline direction of the gas flow. The valve closing state is obtained by the valve closing stopper structure in which the lower end edge 1c of the main body 1 contacts the inner bottom surface 19c of the second exhaust tube 19.

As shown in FIG. 2, the exhaust gas pressure acting central point P acting on the valve main body 1 is inclined at the opening end of the exhaust tube 19 in the muffler (inclination angle θ).
By doing so, the valve shaft 2 and the valve pressure receiving surface are set at a position separated from the position below the vertical line by a vertical line, and a moment in the valve opening direction due to the force of the exhaust gas pressure is obtained. .

The upper end 1d of the valve body 1 is a free end protruding from the second exhaust tube 19, and the upper end 19d of the second exhaust tube 19 is a fully open stopper, so that the valve can be opened.

Next, the operation will be described.

[Low exhaust gas pressure] At low exhaust gas pressure,
As shown in FIG. 4, the valve body 1 is brought into a closed state by its own weight. That is, by setting the valve shaft 2 and the gravitational action point G at positions separated in the streamline direction (horizontal direction) of the gas flow, a closing force automatically acts.

The moment M1 in the valve closing direction is defined by a distance L1 between the valve shaft 2 and the point of gravity G and a force F1 in the valve closing direction due to its own weight applied to the point of gravity G of the valve body 1. M1 = F1 · L1

On the other hand, the moment M2 in the valve opening direction is
When the distance between the valve shaft 2 and the exhaust gas pressure action center point P is L2, and the force in the valve opening direction applied to the exhaust gas pressure action center point P of the valve body 1 is F2, then M2 = F2 · L2.

This force F2 is given by F2 = FP · tan θ, where FP is the wind pressure in the streamline direction of the gas flow applied to the central point P of the exhaust gas pressure action.

When the exhaust gas pressure is low, the wind pressure FP is small, so that the force F2 in the valve opening direction is small, and M1> M
2.

[Exhaust Gas Pressure Increase] When the static pressure or the dynamic pressure of the exhaust gas increases, the exhaust gas pressure is generated in parallel with the flow, but as shown in FIG. As described above, the exhaust gas flows along the surface of the valve body 1, and the pressure distribution acting on the valve body 1 has a pressure peak at the lower portion of the gas passage of the second exhaust tube 19.

That is, the center point P of the exhaust gas pressure acting on the valve body 1 is set at a position separated from the gravity action point G in a downward direction, and the valve opening direction increases as the exhaust gas pressure increases. The moment M2 acts greatly.

Accordingly, when the moment M2 in the valve opening direction exceeds the moment M1 in the valve closing direction due to a rise in the exhaust gas pressure, the valve body 1 starts to rotate leftward in FIG. Then, the lower end edge 1c of the valve body 1 separates from the inner bottom surface 19c of the second exhaust tube 19, and the exhaust gas pressure sensitive valve A starts to open.

When the exhaust gas pressure sensitive valve A starts to open,
As the inclination angle of the valve body 1 increases, the valve body 1 pivots leftward while the exhaust gas pressure action center point P moves toward the lower end edge 1c of the valve body 1 and moves from the solid line position in FIG. The valve is fully opened at a stretch up to the two-dot chain line.

Therefore, when the valve starts to open, the exhaust gas pressure slightly increases and the valve is fully opened at a stretch. When it is desired to obtain the fully opened valve when the engine speed, the engine load, and the like reach a certain level, the setting is facilitated. .

[Exhaust Gas Pressure Decrease] When the exhaust gas pressure decreases with the valve fully opened and the moment M1 in the valve closing direction acting on the exhaust gas pressure sensitive valve A exceeds the moment M2 in the valve opening direction, the valve body 1 Turns right around the valve shaft 2 and the exhaust gas pressure sensitive valve A starts to close.

When the exhaust gas pressure sensitive valve A starts to close,
As the moment M1 in the valve closing direction increases at an accelerated rate as the inclination angle of the valve body 1 decreases, the valve body 1 turns rightward and the valve is completely closed at a stretch.

Therefore, when the valve starts to close, the valve is fully closed at once with a slight decrease in the exhaust gas pressure.

As described above, the valve opening / closing operation with a high response can be obtained when the flow rate is increased and when the flow rate is decreased. As a result, the mute mode can be switched on / off so that the low exhaust gas pressure range can be obtained. Therefore, it is possible to make an optimum setting that achieves both a high noise reduction effect in the engine and an effect of improving the engine output in a high exhaust gas pressure range.

Next, the effects will be described.

(1) The exhaust gas pressure sensitive valve A is provided with a valve main body 1 disposed at the open end inside the muffler of the second exhaust tube 19 having one end opened into the muffler and the other end open to the outside air. A valve shaft 2 that supports the valve body 1 so that the valve body 1 can be opened and closed. The gravitational action point G of the valve body 1 is separated from the valve shaft 2 in the streamline direction of the gas flow so as to obtain a valve closing moment. And the center point P of the exhaust gas pressure acting on the valve body 1 is set at a position where the valve opening direction moment is obtained by the exhaust gas pressure. Compared to the conventional muffler built-in valve that obtains the force in the valve closing direction by spring force, the valve opening operation timing can be obtained stably without being affected by variations and temperature changes, and the valve opening and closing operation with high response It is possible to provide a motor vehicle built-in valve exhaust muffler to achieve mute mode switching.

Incidentally, the present inventor conducted an experiment by setting the inclination angle θ of the valve body 1 to about 33 degrees and gradually increasing the exhaust gas flow rate.

FIG. 5 shows the pressure characteristics of the valve front chamber based on the experimental results, and FIG. 6 shows the characteristics of the valve body inclination angle.

As is apparent from this characteristic, the valve is kept fully closed when the exhaust gas flow rate is 0 to A0, and the valve is fully closed while the exhaust gas flow rate increases from A0 to A1 (about 1.5 m ³ / min). The valve is fully open from closed, and in actual running,
When the accelerator is suddenly depressed, the flow rate of the exhaust gas changes from A0 to A1 instantaneously, so that when the flow rate of the exhaust gas exceeds A0, it is understood that the operation from the fully closed valve to the fully opened valve is performed at once. .

(2) Since the valve body 1 is inclined at the opening end of the exhaust tube 19 inside the muffler, the exhaust gas pressure acting central point P is set at a position where the valve opening direction moment can be obtained by the exhaust gas pressure. Inclination angle θ of main body 1
By setting the above, the valve opening operation timing can be easily tuned.

For example, the shaft hole of the valve shaft 2 is
If the inclination angle θ of the valve body is made long so that it can be changed, and the setting of the valve shaft 2 can be adjusted, the valve opening operation timing can be made different in the same valve body 1. it can.

(Embodiment 2) First, the configuration will be described.

Embodiment 2 corresponds to the first and third aspects of the present invention.

FIG. 7 is a sectional view showing an exhaust gas pressure sensitive valve of an exhaust muffler with a built-in valve for a vehicle according to the second embodiment.

In the second embodiment, the valve main body 1 is arranged perpendicular to the exhaust tube 19, and the valve shaft 2 is shifted to a position higher than the gravitational action point G by an offset to set the exhaust gas pressure action center point P Is set at a position where a moment in the valve opening direction is obtained by the exhaust gas pressure.

The other configuration is the same as that of the first embodiment, and the description is omitted.

The operation is the same as that of the first embodiment, and the description is omitted.

Next, the effects will be described.

In the second embodiment, the following effect is obtained in addition to the effect (1) of the first embodiment.

(3) The center point P of the exhaust gas pressure action is set at a position separated from the valve shaft 2 in a downward direction by setting the offset by shifting the valve shaft 2 to a position above the gravity action point G. By adjusting the offset amount between the pressure and the gravity action point G, the valve opening operation timing can be easily tuned, and the shape of the valve body 1 can be easily set.

For example, when the exhaust tube 19 is cylindrical, the valve body 1 needs to be elliptical in the first embodiment, but in the second embodiment, the valve body 1 is made circular so that the valve is fully closed. Sometimes it can be along the inner surface of the tube.

(Other Embodiments) In the first embodiment, by arranging the valve body 1 at an angle, the exhaust gas pressure acting center point P is set at a position where a valve opening direction moment can be obtained by the exhaust gas pressure. Further, in the second embodiment, an example is set in which the exhaust gas pressure acting center point P is set to a position where a valve opening direction moment can be obtained by the exhaust gas pressure by offset setting in which the valve shaft 2 is shifted to a position above the gravity action point G. However, by using the tilted arrangement of the valve body 1 and the offset setting of the valve shaft 2 together, the exhaust gas pressure acting center point P is set to a position where the valve opening direction moment can be obtained by the exhaust gas pressure. May be.

In the first and second embodiments, an example of application to an exhaust tube having one end inside the muffler and the other end opening to the outside air has been described. You can also.

Further, an example in which the present invention is applied to an exhaust tube having a circular cross section has been described. However, the present invention can also be applied to an exhaust tube having an elliptical, square, or polygonal cross section.

[0066]

According to the first aspect of the present invention, an exhaust gas pressure sensitive valve that opens and closes in accordance with an increase and decrease in exhaust gas pressure due to static pressure and dynamic pressure is provided at an end of the inner tube of the muffler. In an exhaust muffler with a built-in valve for an automobile, an exhaust gas pressure sensitive valve is provided with a valve body disposed at an opening end in a muffler of an exhaust tube having one end opening into the muffler and the other end opening into the outside air or the muffler. A valve shaft that supports the valve body so that the valve body can be opened and closed, and the gravity action point of the valve body is set at a position away from the valve shaft in the streamline direction of the gas flow so as to obtain a moment in the valve closing direction. In addition, since the center point of the exhaust gas pressure acting on the valve body is set at a position where a moment in the valve opening direction can be obtained by the exhaust gas pressure, the valve opening operation timing varies and the temperature changes. It can be provided an automotive valve internal exhaust muffler to achieve mute mode switching by the valve opening and closing operation of the high-response with not sound obtained stably.

In the invention according to claim 2, claim 1 is
In the described exhaust valve muffler with a built-in valve for the vehicle, the valve body is inclined at the opening end of the exhaust tube inside the muffler, so that the exhaust gas pressure acting center point is set to a position where the valve opening direction moment can be obtained by the exhaust gas pressure. In addition to the effects of the first aspect, the valve opening operation timing can be easily tuned by setting the inclination angle of the valve body.

According to the third aspect of the present invention, there is provided the first aspect.
In the exhaust muffler with a built-in valve for the vehicle described, by offsetting the valve shaft to a position above the gravity action point,
Since the center point of the exhaust gas pressure action is set at a position where the valve opening direction moment can be obtained by the exhaust gas pressure, the valve opening operation is achieved by adjusting the offset amount between the valve shaft and the gravitational action point in addition to the effect of the invention described in claim 1. The timing can be easily tuned, and the shape of the valve body can be easily set.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an exhaust gas pressure sensitive valve of an exhaust muffler with a built-in automotive valve according to a first embodiment.

FIG. 2 is a sectional view showing an exhaust gas pressure sensitive valve of the exhaust muffler with a built-in valve for a vehicle according to the first embodiment;

FIG. 3 is an overall sectional view showing an exhaust muffler with a built-in valve for a vehicle according to the first embodiment;

FIG. 4 is an operation explanatory view showing a valve opening / closing state of the exhaust gas pressure sensitive valve according to the first embodiment.

FIG. 5 is a pressure characteristic diagram of a valve front chamber based on an experimental result obtained by performing an experiment by gradually increasing an exhaust gas flow rate using the exhaust gas pressure sensitive valve of the first embodiment.

FIG. 6 is a characteristic diagram of a valve body inclination angle according to an experimental result obtained by performing an experiment by gradually increasing an exhaust gas flow rate using the exhaust gas pressure sensitive valve of the first embodiment.

FIG. 7 is a sectional view showing an exhaust gas pressure sensitive valve of an exhaust muffler with a built-in automotive valve according to a second embodiment.

FIG. 8 is an overall schematic diagram showing a conventional exhaust muffler with a built-in valve for a vehicle.

[Explanation of symbols]

 A Exhaust gas pressure sensitive valve 1 Valve body 2 Valve shaft 19 Second exhaust tube G Gravity action point P Exhaust gas pressure action center point

Claims (3)

[Claims] An exhaust muffler with a built-in valve for an automobile, wherein an exhaust gas pressure sensitive valve (A) that opens and closes in accordance with an increase and decrease in exhaust gas pressure due to static pressure and dynamic pressure is provided in the muffler. A valve body (1) disposed at an opening end in a muffler of an exhaust tube (19) having one end opened in the muffler and the other end opened in the outside air or the muffler; A valve shaft (2) for supporting the main body (1) so as to be able to open and close; and a gravitational action point (G) of the valve main body (1). The exhaust gas pressure acting center point (P) acting on the valve body (1) is set at a position where the valve opening direction moment can be obtained by the exhaust gas pressure. Characterized by Dynamic vehicles valve built-in exhaust muffler. 2. An exhaust muffler with a built-in valve for a vehicle according to claim 1, wherein a valve body (1) is inclined at an opening end of the exhaust tube (19) inside the muffler, so that an exhaust gas pressure action center point (P). ) Is set at a position where a valve opening moment can be obtained by exhaust gas pressure. 3. The exhaust muffler with a built-in valve for a vehicle according to claim 1, wherein the valve shaft (2) is offset to a position higher than a gravity action point (G) so that an exhaust gas pressure action center point (P) is set. An exhaust muffler with a built-in valve for a vehicle, wherein the valve is set at a position where a moment in the valve opening direction can be obtained by exhaust gas pressure.