JP2009215941A - Muffler for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a muffler for a vehicle can achieve the requirements for a reduction in the noise and the back pressure of the exhaust at a high level by flexibly changing the flow pattern of the exhaust using an electronic control valve. <P>SOLUTION: This muffler for a vehicle includes an inlet pipe 4 and an inlet pipe 5 branched from a main pipe 3 on the upstream side of the exhaust and introducing the exhaust gas into a muffler body 2; an outlet pipe 6 and an outlet pipe 7 for exhausting the exhaust gas from the inside of the muffler body 2; a valve V1 installed in the inlet pipe 4 on the outside of the muffler body 2; a valve V2 installed in the outlet pipe 7 on the outside of the muffler body 2; and an ECU 21 for controllably opening and closing both valves V1, V2 according to the operating conditions of an engine. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a muffler for a vehicle.

2. Description of the Related Art Conventionally, a technique for providing a pressure-exhaust-sensitive control valve or an electronic control valve in a silencer body is known (see Patent Documents 1 and 2).
JP 2006-291719 A JP-A-2005-139918

However, since the conventional exhaust pressure sensitive control valve opens and closes according to the exhaust pressure, there is a problem that it cannot be opened and closed at an arbitrary timing like the electronic control valve.
On the other hand, when the electronic control valve is provided in the silencer body, it is difficult to secure an installation space, and the sealing performance and assembly / maintenance performance of each part are also deteriorated.

  The present invention has been made in order to solve the above-mentioned problems, and the object of the present invention is to make it possible to variously change the flow mode of exhaust using an electronic control valve, and to reduce the noise and back pressure of the exhaust. It is providing the silencer for vehicles which can achieve the demand of this at a high level.

  In the first aspect of the present invention, a plurality of inlet pipes branched from the main pipe on the upstream side of the exhaust and introducing exhaust into the silencer body, and a plurality of outlet pipes for discharging exhaust from the silencer body, respectively A first electronic control valve provided at a position outside the silencer body in any one of the plurality of inlet pipes; and a silencer body outside the silencer body in any one of the plurality of outlet pipes. A second electronic control valve provided at a position, and a control means for performing opening / closing control of both electronic control valves according to the operating state of the engine are provided.

In the first aspect of the invention, the control means controls the opening and closing of both electronic control valves according to the operating state of the engine.
Thus, at least four exhaust circulation modes can be formed according to the open / closed states of the first electronic control valve and the second control valve.
Therefore, the flow mode of the exhaust gas can be changed in various ways using the electronic control valve, and the demand for low exhaust gas noise and low back pressure can be achieved at a high level.
In addition, since the electronic control valve is provided outside the silencer body in the inlet pipe and the outlet pipe, it is not necessary to secure a space for installing the electronic control valve in the silencer body, ensuring sealing performance and assembly / Maintenance etc. are easy and practical adoption becomes easy.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
FIG. 1 is a plan view showing a muffler for a vehicle according to the first embodiment, FIG. 2 is a diagram for explaining the inside of the muffler for a vehicle according to the first embodiment, and FIG. 3 is a flowchart for explaining the opening / closing control of the valve according to the first embodiment. 4-7 is a figure explaining the effect | action of the silencer for vehicles of Example 1. FIG.

First, the overall configuration will be described.
As shown in FIGS. 1 and 2, in the vehicle silencer 1 according to the first embodiment, the silencer body 2, the main pipe 3, the inlet pipe 4 (corresponding to the first inlet pipe in the claims), and the inlet pipe 5. (Corresponding to a second inlet pipe in claims), an outlet pipe 6 (corresponding to a second outlet pipe in claims), an outlet pipe 7 (corresponding to a first outlet pipe in claims), and the like.

The silencer main body 2 is sealed inside by a cylindrical shell 8 and substantially vessel-shaped end plates 9 and 10 that close both open ends of the shell 8.
The shell 8 is formed in a cylindrical shape by winding a flat base material in multiple layers, and is fixed by a plurality of spot welds X1 in which a winding direction start end portion and a termination end portion are provided along the axial direction. ing.
In addition, the open end portions of the corresponding end plates 9 and 10 are overlapped inside the open end portion of the shell 8, and both of them are fixed by welding (not shown) over the entire circumference.

The inside of the silencer body 2 is divided by three plate-like baffle plates 11 to 13, and thereby, four chambers R <b> 1 to R <b> 4 are formed in the silencer body 2.
The outer peripheral parts of the baffle plates 11 to 13 are fixed to the shell 8 by spot welding (not shown).

  A flange 3a connected to an engine-side connection pipe (not shown) is fixed to the exhaust upstream end of the main pipe 3, while the exhaust downstream side is branched into inlet pipes 4 and 5.

  The inlet pipe 4 bends in an approximately L shape along the axial direction of the main pipe 3, and further passes through the end plate 9 and the baffle plates 11 to 13, and its downstream end on the exhaust side communicates with the chamber R4. ing.

Further, a butterfly valve V1 (corresponding to the first electronic control valve in the claims) is built in the inlet pipe 4 at a position outside the silencer body 2 as an electronic control valve.
The valve V1 is provided so that it can be opened and closed by rotating a rotating shaft 15 fixed to a disc-like valve body 14 around the shaft, and the rotating shaft 15 is driven to rotate by an actuator 16 that simplifies the illustration. It has become.
Further, a plurality of small holes 4 a communicating with the chamber R <b> 3 are formed in the middle of the inlet pipe 4.
The total opening area of the small holes 4 a is set to be larger than the opening end of the inlet pipe 4.

  The inlet pipe 5 is bent in a state where it branches off in the direction perpendicular to the axis of the main pipe 3, and further passes through the end plate 9 and the baffle plate 11, and its downstream end on the exhaust side communicates with the chamber R2.

The outlet pipe 6 is disposed in a state of penetrating the end plate 10 and the baffle plates 11 to 13, and its exhaust upstream side end portion communicates with the chamber R 1, while the exhaust downstream side end portion communicates with the outside. Yes.
A plurality of small holes 6 a communicating with the chamber R <b> 3 are formed in the middle of the outlet pipe 6.

The outlet pipe 7 is disposed in a state of penetrating the end plate 10 and the baffle plates 12 and 13, and its exhaust upstream side end portion is communicated with the chamber R 2, while the exhaust downstream side end portion is communicated with the outside. Yes.
Further, a butterfly valve V2 (corresponding to the second electronic control valve in the claims) is built in the outlet pipe 7 at a position outside the silencer body 2 as an electronic control valve.
Similarly to the valve V1, the valve V2 is provided so that it can be opened and closed by rotating a rotary shaft 18 fixed to the disc-like valve body 17 around the axis, and the rotary shaft 18 is an actuator 19 for simplifying the illustration. Is driven to rotate.
Furthermore, a plurality of small holes 7a communicated with the chamber R4 are formed in the middle of the outlet pipe 7.

Further, the baffle plate 11 is provided with a communication pipe 20 that brings the chambers R1 and R2 into communication with each other.
In addition, the penetration part of the end plates 9 and 10 and the baffle plate in each of the pipes 4 to 7 and 20 is fixed by welding (not shown) over the entire circumference.

The drive control of the actuators 16 and 19, that is, the opening and closing control of the valves V 1 and V 2, is an ECU 21 that detects and controls the operating state of the engine from the detection results of the various sensors 22 (Engine Control Unit, corresponding to the control means in the claims) Is to be done by.
In addition, all the structural members of the vehicle silencer of the first embodiment are made of metal.

Next, an example of the opening / closing control of the valves V1, V2 by the ECU 21 will be described based on the flowchart of FIG.
In the first embodiment, the ECU 21 performs opening / closing control of the valves V <b> 1 and V <b> 2 using the detection result of the existing engine speed sensor (corresponding to the detection means in the claims) which is one of the various sensors 22. .
Note that an existing accelerator opening sensor, intake air amount sensor, or the like may be used instead of the rotational speed sensor, or a sensor for detecting the operating state of the engine may be newly provided.
The control described below is processing that is repeatedly performed by the ECU 21 at predetermined time intervals from the start to the end of the engine.

  First, in step S1, the engine speed N is detected.

Next, in step S2, it is determined whether or not the engine speed N detected in step S1 is a preset low speed range (for example, 1000 rpm ≦ N), and if it is a low speed range, the process proceeds to step S3. If not in the low rotation range, the process proceeds to step S4.
In step S4, it is determined whether or not the engine speed N detected in step S1 is a preset medium rotation range 1 (for example, 1000 rpm <N ≦ 3000 rpm). If the rotation range is medium rotation range 1, the process proceeds to step S5. If it is not the middle rotation region 1, the process proceeds to step S6.
In step S6, it is determined whether or not the engine speed N detected in step S1 is in a preset middle speed range 2 (for example, 3000 rpm <N <5000 rpm). If it is in the middle speed range 2, the process proceeds to step S7. If it is not the middle rotation region 2, the process proceeds to step S8.
In step S8, it is determined whether or not the engine speed N detected in step S1 is a preset high speed range (for example, 5000 rpm <N). If not, the process ends.
In the first embodiment, when it is determined in step S8 that it is not in the high rotation range, the process is ended, and the process is repeated from step S1 after a predetermined time when the process is repeated. You may make it return to step S1 before time progress.

In step S3, the valves V1 and V2 are closed and the process is terminated.
In step S5, the valve V1 is opened and the valve V2 is closed to finish the process.
In step S6, the valve V1 is closed and the valve V2 is opened to end the process.
In step S9, the valves V1 and V2 are opened and the process is terminated.

Next, the operation will be described.
<About muffling action>
In the vehicle silencer 1 configured as described above, the ECU 21 detects the engine speed N when the engine starts (step S1).

<At low engine speed>
When the engine speed N is a preset low speed range, the valves V1 and V2 are closed as shown in FIG. 4 (step S2 → step S3).

As a result, the entire amount of exhaust gas (shown by broken line arrows) discharged from the engine flows into the chamber R2 via the inlet pipe 5 of the main pipe 3.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R2, and the chamber R2 functions as an expansion chamber.
Further, the noise energy of the exhaust gas flowing into the chamber R2 can enter the chamber R4 through the small hole 7a of the outlet pipe 7 and can be silenced by the resonance action, and the chamber R4 functions as a resonator chamber.

Next, the exhaust gas flowing into the chamber R2 flows into the chamber R1 through the communication pipe 20, and is further discharged out of the silencer body 2 through the outlet pipe 6.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R1, and the chamber R1 functions as an expansion chamber.
Further, the noise energy of the exhaust from the outlet pipe 6 can enter the chamber R3 through the small hole 6a and can be silenced by the resonance action, and the chamber R3 functions as a resonator chamber.

  Therefore, the chambers R1 and R2 can function as expansion chambers, and the chambers R3 and R4 can function as resonator chambers, and noise reduction required when the engine speed is in a low rotation range can be realized.

<During engine rotation>
When the engine speed N is in the middle speed range 1, as shown in FIG. 5, the valve V1 is opened and the valve V2 is closed (step S4 → step S5).

As a result, the exhaust discharged from the engine (illustrated by broken line arrows) branches from the main pipe 3 to the inlet pipe 4 and the inlet pipe 5.
The exhaust gas flowing into the inlet pipe 5 flows into the chamber R2.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R2, and the chamber R2 functions as an expansion chamber.
Further, the noise energy of the exhaust gas flowing into the chamber R2 can enter the chamber R4 through the small hole 7a of the outlet pipe 7 and can be silenced by the resonance action, and the chamber R4 functions as a resonator chamber.
Next, the exhaust gas flowing into the chamber R2 flows into the chamber R1 through the communication pipe 20, and is further discharged out of the silencer body 2 through the outlet pipe 6.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R1, and the chamber R1 functions as an expansion chamber.

On the other hand, the exhaust from the inlet pipe 4 flows into the chamber R3 through the small hole 4a.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R3, and the chamber R3 functions as an expansion chamber.
Further, the noise energy of the exhaust from the inlet pipe 5 can enter the room R4 and be silenced by the resonance action, and the room R4 functions as a resonator room.
Next, the exhaust gas flowing into the chamber R3 flows into the small hole 6a of the outlet pipe 6 and is then discharged out of the silencer body 2.

Therefore, the chambers R1 to R3 can be functioned as an expansion chamber and the chamber 4 can be functioned as a resonator chamber, and the noise reduction required during the middle rotation of the engine can be realized.
Further, the inlet pipe 4 is set to have the same diameter as the main pipe 3 and larger than the pipe diameter of the inlet pipe 5 and further has a shape along the flow direction of the exhaust of the main pipe 3. Exhaust gas can be introduced and discharged out of the silencer main body 2 to achieve a low back pressure required during mid-rotation of the engine.

<During engine rotation>
When the engine speed N is in the middle speed range 2, as shown in FIG. 6, the valve V1 is closed and the valve V2 is opened (step S6 → step S7).

As a result, the entire amount of exhaust gas (shown by broken line arrows) discharged from the engine flows into the chamber R2 via the inlet pipe 5 of the main pipe 3.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R2, and the chamber R2 functions as an expansion chamber.
Next, part of the exhaust gas flowing into the chamber R2 is discharged out of the silencer body 2 through the outlet pipe 7.
At this time, the noise energy of the exhaust gas from the outlet pipe 7 is caused to enter the chamber R4 through the small hole 7a and can be silenced by the resonance action, and the chamber R4 functions as a resonator chamber.

On the other hand, a part of the exhaust gas flowing into the chamber R2 flows into the chamber R1 through the communication pipe 20, and is further discharged out of the silencer body 2 through the outlet pipe 6.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R1, and the chamber R1 functions as an expansion chamber.
Further, the noise energy of the exhaust from the outlet pipe 6 can enter the chamber R3 through the small hole 6a and can be silenced by the resonance action, and the chamber R3 functions as a resonator chamber.

Accordingly, the chambers R1 and R2 can function as expansion chambers, and the chambers R3 and R4 can function as resonator chambers, and low noise required during the middle rotation of the engine can be realized.
Further, since the outlet pipe 7 communicates directly with the outside of the silencer main body 2, more exhaust gas flows into the outlet pipe 7 and is discharged out of the silencer main body 2 compared to the communication pipe 20 side which is a bypass. It is possible to achieve the low back pressure required during mid-rotation of the engine.

<At high engine speed>
When the engine speed N is in a high speed range, as shown in FIG. 7, the valves V1 and V2 are opened (step S8 → step S9).

As a result, the exhaust discharged from the engine (illustrated by broken line arrows) branches from the main pipe 3 to the inlet pipe 4 and the inlet pipe 5.
The exhaust from the inlet pipe 5 flows into the chamber R2.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R2, and the chamber R2 functions as an expansion chamber.
Next, the entire amount of the exhaust gas flowing into the chamber R2 is discharged out of the silencer body 2 via the outlet pipe 7.
At this time, the noise energy of the exhaust gas in the chamber R2 can enter the chamber R1 through the communication pipe 20 and can be silenced by the resonance action, and the chamber R1 functions as a resonator chamber.

On the other hand, the exhaust from the inlet pipe 4 flows into the chambers R3 and R4 in the silencer body 2 through the small holes 4a.
At this time, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R3 from the small hole 4a, and the chamber R3 functions as an expansion chamber.
Further, the sound can be silenced by the expansion / contraction action of the exhaust gas flowing into the chamber R4 from the inlet pipe 4, and the chamber R4 functions as an expansion chamber.
Next, the exhaust gas flowing into the chamber R3 flows into the small hole 6a of the outlet pipe 6 and is then discharged out of the silencer body 2.
At this time, the noise energy of the exhaust enters the room R1 from the outlet pipe 6 and can be silenced by a resonance action, and the room R1 functions as a resonator room.
On the other hand, the exhaust gas flowing into the chamber 4 flows into the small hole 7 a of the outlet pipe 7 and is then discharged out of the silencer body 2.

Therefore, the chambers R2 to R4 can function as an expansion chamber, and the chamber R1 can function as a resonator chamber, so that noise reduction during high engine rotation can be realized.
Further, since the outlet pipe 7 communicates directly with the outside of the silencer body 2, more exhaust gas can be introduced into the outlet pipe 7 and discharged out of the silencer body 2 than the side of the communication pipe 20. Low back pressure required at high rotation can be achieved.
Further, the inlet pipe 4 is set to have the same diameter as the main pipe 3 and larger than the pipe diameter of the inlet pipe 5 and further has a shape along the flow direction of the exhaust of the main pipe 3. Exhaust gas can be introduced and discharged out of the silencer main body 2 to achieve a low back pressure required when the engine rotates at high speed.

Thus, in the first embodiment, four exhaust flow modes can be formed according to the engine speed, that is, the engine operating state, depending on the open / closed state of the valves V1 and V2.
In addition, it is required in the case of high rotational speed and low noise required when the engine speed is in the low rotational range, low noise and low back pressure required in the middle rotational range. The low back pressure can be realized, and the demand for low exhaust noise and low back pressure can be achieved at a high level.

<Changes in room functions>
Further, the chambers R1, R3, and R4 can be changed to function as an expansion chamber and a resonator chamber depending on the open / closed state of the valves V1 and V2, and the characteristics (capacity) of the expansion chamber and the resonator chamber can be provided without providing a new chamber. ) Can be changed.

<Valve installation position>
Further, since the valves V1 and V2 corresponding to the positions of the inlet pipe 4 and the outlet pipe 7 outside the silencer main body 2 are provided, the installation space and the sealing performance are ensured as compared with the case where they are provided in the silencer main body 2. Assembling and maintenance are easy and practical use is easy.

Next, the effect will be described.
As described above, in the invention of the first embodiment, the inlet pipes 4 and 5 that are branched from the main pipe 3 on the exhaust upstream side and introduce exhaust into the silencer body 2 and the exhaust from the silencer body 2 are exhausted. Outlet pipes 6 and 7, a valve V 1 provided at a position outside the silencer body 2 in the inlet pipe 4, a valve V 2 provided at a position outside the silencer body 2 in the outlet pipe 4, and engine operation Since the ECU 21 that controls the opening and closing of the valves V1 and V2 according to the state is provided, the flow mode of the exhaust can be changed variously using the electronic control valve, and the demand for low noise and low back pressure of the exhaust is high. Can be achieved.

  Further, since the valves V1 and V2 are provided at positions outside the silencer body 2 in the inlet pipe 4 and the outlet pipe 7, respectively, it is not necessary to secure a space for installing the valve in the silencer body 2, and ensuring sealing performance. And assembly / maintenance, etc. are easy, and practical adoption becomes easy.

  The ECU 21 closes the valves V1 and V2 when the engine speed detected by the speed sensor 22 is in a low speed range, and closes the valves V1 and V2 when the engine speed is in a middle speed range. When either one of V2 is opened and the other is closed, and the engine speed is in a high speed range, the valves V1 and V2 are opened. Achieving both low noise required in the low rotation range, low noise and low back pressure required in the mid rotation range, and low back pressure required in the high rotation range .

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.
For example, the specific structure within the silencer body can be set as appropriate.
The number of inlet pipes and outlet pipes can be set as appropriate.
Further, the valves V1 and V2 can be opened and closed stepwise or continuously.

It is a top view which shows the silencer for vehicles of Example 1. It is a figure explaining the inside of the silencer for vehicles of Example 1. It is a flowchart explaining the opening / closing control of the valve | bulb of Example 1. FIG. It is a figure explaining the effect | action of the vehicle silencer of Example 1. FIG. It is a figure explaining the effect | action of the vehicle silencer of Example 1. FIG. It is a figure explaining the effect | action of the vehicle silencer of Example 1. FIG. It is a figure explaining the effect | action of the vehicle silencer of Example 1. FIG.

Explanation of symbols

R1, R2, R3, R4 Chamber V1, V2 valve (electronic control valve)
X1 spot welding 1 vehicle silencer 2 silencer body 3 main pipe 3a flange 4, 5 inlet pipe 6, 7 outlet pipe 6a, 7a small hole 8 shell 9, 10 end plates 11, 12, 13 baffle plate 14 valve body 15 Rotating shaft 16 Actuator 17 Valve body 18 Rotating shaft 19 Actuator 20 Communication pipe 21 ECU
22 Various sensors (rotational speed sensor)

Claims (2)

A plurality of inlet pipes branched from the main pipe on the upstream side of the exhaust and introducing exhaust into the silencer body,
A plurality of outlet pipes each discharging exhaust from the silencer body;
A first electronic control valve provided at a position outside the silencer body in any of the plurality of inlet pipes;
A second electronic control valve provided at a position outside the silencer body in any one of the plurality of outlet pipes;
A muffler for a vehicle comprising control means for performing opening / closing control of both electronic control valves in accordance with an operating state of the engine. The muffler for a vehicle according to claim 1,
A detecting means capable of detecting at least the engine speed,
A plurality of inlet pipes are constituted by two of a first inlet pipe and a second inlet pipe, and the first electronic control valve is provided in the first inlet pipe,
A plurality of outlet pipes are constituted by two of a first outlet pipe and a second outlet pipe, and the second electronic control valve is provided in the first outlet pipe,
When the engine speed detected by the detecting means is in a low speed range, the control means closes both electronic control valves,
When the engine speed is in the middle speed range, either one of the two electronic control valves is opened and the other is closed.
When the engine speed is in a high engine speed range, the vehicle silencer is characterized in that both electronic control valves are opened.

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