JPH10299453A - Exhaust muffler with built-in valve for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust muffler with a built-in valve for an automobile to perform switching of a muffling mode through high responsiveness valve opening and closing operation though the cost is low and prevent the generation of tramp noise and vibration during full closing of a valve. SOLUTION: A flow rate-sensitive value A comprises a valve body 1 arranged at the opening end in a muffler of a second exhaust output tube 19 having one end part opened to the interior of a muffler and the other end opened to outside air; a valve shaft 2 to openably and rotatably support the valve body 1; and a flow rate-sensitive member 3 arranged on the valve shaft 2 and extended in an opposite direction to the valve body 1 based on the valve shaft 2 and arranged at the outlet part of an exhaust input tube 15. The gravity working point of the flow rate-sensitive member 3 is set in a manner to be offset from the valve shaft 2 in a manner to generate a valve closing direction moment. Further, the exhaust gas pressure receiving area of the flow rate- sensitive member 3 is set such that during full closing of a valve, the area is reduced to a minimum value and the area is gradually increased with the increase of a valve opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of an exhaust muffler with a built-in valve for a vehicle, in which a flow sensing valve which opens and closes in accordance with an increase and decrease in an exhaust flow rate is provided at an end of an inner tube of a muffler.

[0002]

2. Description of the Related Art Conventionally, as an exhaust muffler with a built-in valve for a vehicle, for example, a muffler shown in FIG. 6 has been known (see International Publication WO95 / 13460).

In this exhaust muffler, as shown in FIG. 6, a valve (in this case, the opening area of a tube is changed) installed in the muffler is closed by a spring force, but is compressed by an exhaust gas flow. The valve is opened to keep the internal gas pressure constant.

[0004]

However, in the above-described conventional exhaust muffler with a built-in valve for a vehicle, a constant spring force acts even when the valve is at any valve opening position from a fully closed position to a fully opened position. Therefore, it has the following problems.

(1) The valve opening is proportional to the exhaust gas flow rate,
Only by controlling the internal gas pressure to a constant pressure, it is possible to perform control that achieves both a high noise reduction effect by fully closing the valve in the low flow rate range and an engine output improvement effect by fully opening the valve in the high flow rate range. Can not.

(2) Since the exhaust gas directly hits the valve body from the muffler inner tube, when the exhaust gas flow rate fluctuates at the exhaust gas flow level at which the valve starts to open from the fully closed state, the opening and closing of the valve is repeated, Flaps and vibrations are generated due to repeated collision between the valve body and the seat surface.

[0007] In order to solve these problems, there is also a device that uses an actuator such as a motor to detect the engine speed and exhaust pressure, and controls the opening and closing of the valve by driving the actuator when the detected value reaches a set threshold value. It has been proposed (see, for example, FIG. 4 of JP-A-2-81911,
(Fig. 5), the system becomes very expensive due to the need to add an electronic control system such as an actuator.

Further, as a device for controlling an opening area of a tube in a muffler using a bimetal or a shape memory alloy whose shape changes with temperature, a device described in Japanese Patent Application Laid-Open No. 61-96117 is known. However, since this device also uses expensive members, the system becomes very expensive, and since it is used in a muffler which is a high-temperature atmosphere, high thermal durability is required.

It is an object of the present invention to achieve a low-cost, high-response muffler mode switching by a valve opening / closing operation with a high response, and no flapping noise or vibration when a valve is fully closed. Is to provide.

[0010]

[Means for Solving the Problems]

According to a first aspect of the present invention, there is provided an exhaust muffler with a built-in valve for a vehicle, wherein a flow-sensitive valve that opens and closes in accordance with an increase or a decrease in an exhaust flow rate is provided at an end position of a tube inside the muffler. A valve body disposed at a muffler opening end of an exhaust output tube having one end opening into the muffler and the other end opening into the outside air or the muffler; A valve shaft movably supported, and a flow sensing member provided on the valve shaft, extending in a direction opposite to the valve body with respect to the valve shaft, and disposed at an outlet of an exhaust input tube; The gravity action point of the sensing member is set to be offset from the valve axis so that a moment in the valve closing direction is obtained, and the exhaust gas receiving pressure area received by the flow rate sensing member is set when the valve is fully closed. In minimum area, and characterized in that a setting area is accompanied to the increase of the valve opening is enlarged.

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 the exhaust gas in the muffler is provided at a central position of the valve body when the valve is fully closed. Has a gas flow hole for producing an exhaust gas flow flowing toward the inside of the exhaust output tube.

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 flow rate sensing member is fixed to a valve shaft. One end is fixed to the strut portion and the strut portion, and has a semi-cylindrical shape having an outer diameter slightly smaller than the inner diameter of the exhaust input tube and a thickness that becomes the exhaust gas receiving pressure area when the valve is fully closed, and a part is inside the exhaust input tube. And a flow rate sensor disposed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

 Embodiment 1 First, the configuration will be described.

Embodiment 1 corresponds to the first, second and third aspects of the present invention.

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

In FIG. 3, A is a flow rate 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, 1
5 is an exhaust input tube, 16 is a first tube, 17 is a second tube, 18 is a first exhaust output tube, and 19 is a second exhaust tube.
Exhaust output tube, 20 is the first chamber, 21 is the second chamber, 22
Is the third room.

The flow-sensitive valve A is a valve that opens and closes as the flow rate of the exhaust gas increases and decreases. The valve A is disposed at the open end inside the muffler of the second exhaust output tube 19 that communicates the second chamber 21 with the outside air.

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 open to the first chamber 20 and the other end open to the second chamber 21.

The first exhaust output tube 18 is provided so as to penetrate the first baffle plate 13 and the second baffle plate 14, and has one end opening to the first chamber 20 and the other end opening to the outside air. I have.

The second exhaust output tube 19 is provided through the second baffle plate 14, and has a flow-sensitive valve A at one end and an open end at the other end. When A opens, the second chamber 21 communicates with the outside air.

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

1 and 2, A is a flow sensitive valve, 1 is a valve body, 2 is a valve shaft, 3 is a flow sensing member, 4 is a gas flow hole, 5 is a shaft support bracket, and 14 is a second support bracket.
A baffle plate, 15 is an exhaust input tube, and 19 is a second exhaust output tube.

The valve main body 1 is disposed at an open end in the muffler of the second exhaust output tube 19, one end of which is open into the muffler and the other end is open to the outside air.

The valve shaft 2 is a shaft for supporting the valve body 1 so as to be able to open and close, and is supported at both ends by a shaft support bracket 5 fixed to a second baffle plate 14 or the like.

The flow rate sensing member 3 is provided on the valve shaft 2, extends in a direction opposite to the valve body 1 with respect to the valve shaft 2, and is disposed at an outlet of the exhaust input tube 15. A support 3a fixed to the support 2 and a support 3a
Has a semi-cylindrical shape having an outer diameter slightly smaller than the inner diameter of the exhaust input tube 15 and a thickness that becomes an exhaust gas pressure receiving area when the valve is fully closed, and a part of which is disposed in the exhaust input tube 15. And a sensing unit 3b. With this configuration, the gravitational action point of the flow rate sensing member 3 is set to be offset from the valve shaft 2 so as to obtain a valve closing moment (see FIG. 4), and the flow rate sensing member 3 receives exhaust gas. The gas receiving pressure area is a minimum area based on the thickness of the half cylinder when the valve is fully closed, and the exhaust gas receiving pressure area is set to increase by increasing the projected area of the semi-cylindrical peripheral surface as the valve opening increases.

The gas flow hole 4 is formed at a central position of the valve body 1 and exhaust gas in the muffler is discharged to the second position when the valve is fully closed.
An exhaust gas flow flowing into the exhaust output tube 19 is created.

Next, the operation will be described.

[Low Flow] At low flow, as shown in FIG. 4, the gravity sensing point of the flow sensing member 3 is offset from the valve shaft 2 so that the flow sensing member 3 receives gravity. Is greater than the moment in the valve opening direction due to the force F2 acting on the minimum exhaust gas receiving pressure area due to the cylindrical thickness of the flow rate sensor 3b, and the valve body 1 is connected to the second exhaust output tube 19 by the force F1. A valve closed state in close contact with the open end is obtained.

In addition, since the gas flow hole 4 is formed at the center position of the valve body 1, the exhaust gas in the muffler flows toward the inside of the second exhaust output tube 19 when the valve is fully closed. Due to this exhaust dynamic pressure, the force in the direction of closing the valve body 1 increases, and the valve body 1
A valve closed state in which the exhaust output tube 19 is in close contact with the open end is obtained.

[When the flow rate increases] When the flow rate of the exhaust gas from the exhaust input tube 15 increases and the moment in the valve opening direction due to the force F2 acting on the exhaust gas pressure receiving area exceeds the moment in the valve closing direction, as shown in FIG. Then, the valve body 1 and the flow sensing member 3 start to rotate rightward in the drawing about the valve shaft 2, and the valve body 1 moves away from the opening end of the second exhaust output tube 19, and the flow sensitive valve A starts to open.

When the flow sensing valve A starts to open, as is apparent from FIG. 5, the projected area of the semi-cylindrical peripheral surface of the flow sensing unit 3b increases, so that the exhaust gas receiving pressure area increases with the valve opening, and the flow rate increases. As the force acting on the sensing portion 3b increases, the valve body 1 rotates rightward and the valve is fully opened at a stretch.

Therefore, when the valve starts to open, the valve becomes fully open at a stretch just by slightly increasing the flow rate of the exhaust gas. If it is desired to fully open the valve when the engine speed, the engine load, etc. reach a certain level, it is easy to set. Become.

[When the flow rate decreases] When the flow rate of the exhaust gas decreases in the fully opened state of the valve and the valve closing direction moment acting on the flow rate sensitive valve A exceeds the valve opening direction moment,
As the valve body 1 approaches the open end of the second exhaust output tube 19, the flow-sensitive valve A starts to close.

When the flow sensing valve A starts to close, the projected area of the semi-cylindrical peripheral surface of the flow sensing part 3b decreases, so that the exhaust gas receiving pressure area decreases with the valve opening, and the force acting on the flow sensing part 3b decreases. As a result, the valve body 1 rotates to the left and the valve is completely closed at a stretch. Therefore, when the valve starts to close, the valve is completely closed at once with a slight decrease in the flow rate of the exhaust gas.

As described above, the valve opening / closing operation with a high response can be obtained when the flow rate increases and when the flow rate decreases. As a result, the mute mode can be switched on / off, so that the low flow rate range can be obtained. It is possible to make an optimal setting that achieves both a high noise reduction effect and an engine output improvement effect in a high flow rate region.

Next, the effects will be described.

(1) The flow-sensitive valve A is provided with a valve body 1 disposed at an open end in the muffler of the second exhaust output 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 it can be opened and closed; and a valve shaft 2 provided on the valve shaft 2. The flow sensing member 3 is provided with an offset point from the valve shaft 2 so that a valve closing moment is obtained, and an exhaust gas receiving pressure area received by the flow sensing member 3 is provided. Is set to have the minimum area when the valve is fully closed, and the area expands as the valve opening increases, so it is lower in cost than conventional valves with built-in mufflers such as electronic control systems.
It is possible to provide an exhaust muffler with a built-in valve for a vehicle, which achieves a silencing mode switching by a high-response valve opening / closing operation and does not generate fluttering noise or vibration when the valve is fully closed.

(2) Exhaust gas in the muffler is placed at the center position of the valve body 1 when the valve is fully closed.
Since the gas flow holes 4 for creating the exhaust gas flow flowing inward are formed, it is possible to obtain a valve closed state in which the valve body 1 strongly adheres to the opening end of the second exhaust output tube 19 at a low flow rate.

(3) The flow rate sensing member 3 has a column 3a fixed to the valve shaft 2 and one end fixed to the column 3a.
It has a semi-cylindrical shape having an outer diameter slightly smaller than the inner diameter of the exhaust input tube 15 and a thickness to be an exhaust gas pressure receiving area when the valve is fully closed, and is constituted by a flow rate sensing portion 3 b partially disposed in the exhaust input tube 15. Therefore, a high flow rate sensing accuracy can be obtained by the arrangement in the tube without disturbing the flow of the exhaust gas or reducing the flow rate due to the shape along the exhaust gas flow line.

(Other Embodiments) In the first embodiment, an example has been shown in which the valve is fully closed only by gravity when the flow rate is low. However, a weak spring force is applied to the valve shaft by a spring, and gravity and low spring force are applied. May be used to secure the fully closed state of the valve.

In the first embodiment, as the flow rate sensing member,
Although a member having a semi-cylindrical shape and having a flow rate sensing portion partially disposed in the exhaust input tube is used, the shape and arrangement thereof are not limited to the first embodiment. You may change it suitably according to a tube layout etc.

In the first embodiment, an example is described in which the flow rate responsive valve is installed between the exhaust input tube and the exhaust output tube both of which are in open communication with the outside air. However, the present invention is not limited to this embodiment, and the input and output of exhaust (or It can also be applied to the case of switching the exhaust circulation circuit between the exhaust tubes inside the muffler that has a relationship of (inlet and outlet) and does not communicate with the open air to the outside air. Can also be applied.

[0045]

According to the first aspect of the present invention, there is provided an exhaust muffler with a built-in valve for a vehicle, wherein a flow sensing valve which opens and closes in accordance with an increase or decrease of the exhaust flow is provided at an end position of a tube inside the muffler. The sensitive valve has a valve body located at the open end inside the muffler of the exhaust output tube, one end of which opens into the muffler and the other end opens to the outside air or muffler, and the valve body is opened and closed rotatably. A valve shaft, and a flow sensing member provided on the valve shaft, extending in a direction opposite to the valve body with respect to the valve shaft, and disposed at an outlet of the exhaust input tube. Is set to be offset from the valve axis so as to obtain a valve closing direction moment, and the exhaust gas receiving pressure area received by the flow rate sensing member is the minimum area when the valve is fully closed, and the valve opening degree is Since the area is enlarged as the size increases, the low-cost, high-response valve opening / closing operation switches to the mute mode, and there is no flapping noise or vibration when the valve is fully closed. A muffler can be provided.

In the invention according to claim 2, claim 1
2. The exhaust muffler with a built-in valve for a vehicle according to claim 1, wherein a gas flow hole for creating an exhaust gas flow in which exhaust gas in the muffler flows toward the inside of the exhaust output tube when the valve is fully closed is formed at a central position of the valve body. In addition to the effects of the invention described above, it is possible to obtain a valve closed state in which the valve body strongly adheres to the open end of the exhaust output tube at a low flow rate.

In the invention according to claim 3, claim 1
The exhaust muffler with a built-in valve for a vehicle according to claim 2, wherein the flow rate sensing member comprises a support fixed to the valve shaft, one end fixed to the support, an outer diameter slightly smaller than the inner diameter of the exhaust input tube, and the entire valve. A semi-cylindrical shape having a thickness that becomes an exhaust gas receiving pressure area when closed, and a part thereof is constituted by a flow rate sensing portion arranged in the exhaust input tube, so that in addition to the effects of the invention described in claim 1 or 2, In addition, a high flow rate sensing accuracy can be obtained by disposing in the tube without disturbing the flow of the exhaust gas or reducing the flow rate due to the shape along the exhaust gas flow line.

[Brief description of the drawings]

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

FIG. 2 is a front view showing a flow-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 closed state of the flow rate sensitive valve according to the first embodiment.

FIG. 5 is an operation explanatory view showing a valve open state of the flow rate sensitive valve according to the first embodiment.

FIG. 6 is a perspective view showing a conventional exhaust muffler built-in valve.

[Explanation of symbols]

 A Flow Sensitive Valve 1 Valve Body 2 Valve Shaft 3 Flow Sensing Member 3a Support 3b Flow Sensing Part 4 Gas Flow Hole 5 Shaft Support Bracket 14 Second Baffle Plate 15 Exhaust Input Tube 19 Second Exhaust Output Tube

Claims (3)

[Claims] 1. An exhaust muffler with a built-in valve for a vehicle, wherein a flow responsive valve (A) that opens and closes in accordance with an increase or decrease in an exhaust flow rate is provided at an end position of an inner tube of a muffler. A valve body (1) disposed at an open end inside the muffler of an exhaust output tube (19) having one end opened into the muffler and the other end open to the outside air or the muffler; A valve shaft (2) supported to be openable and closable; and an exhaust input tube (15) provided on the valve shaft (2), extending in a direction opposite to the valve body (1) with respect to the valve shaft (2). (3) Flow rate sensing member arranged at the outlet of (3)
Wherein the gravitational action point of the flow rate sensing member (3) is set offset from the valve shaft (2) so as to obtain a valve closing moment, and the exhaust gas received by the flow rate sensing member (3) is provided. An exhaust muffler with a built-in valve for an automobile, wherein the pressure receiving area is set to a minimum area when the valve is fully closed, and the area is increased as the valve opening increases. 2. The exhaust muffler according to claim 1, wherein the exhaust gas in the muffler flows toward the exhaust output tube (19) at a center position of the valve body (1) when the valve is fully closed. An exhaust muffler with a built-in valve for a vehicle, wherein a gas flow hole (4) for creating a gas flow is formed. 3. The exhaust muffler with a built-in valve for a vehicle according to claim 1, wherein the flow rate sensing member (3) includes a support (3a) fixed to a valve shaft (2), and a support (3). 3a) has a semi-cylindrical shape, one end of which is fixed to an outer diameter slightly smaller than the inner diameter of the exhaust input tube (15) and a thickness which becomes an exhaust gas receiving pressure area when the valve is fully closed, and a part of which is an exhaust input tube (15).
An exhaust muffler with a built-in valve for a vehicle, characterized by comprising a flow sensor (3b) disposed in the interior.