JPH08240158A - Egr device - Google Patents

Abstract

PURPOSE: To provide an EGR device free from emitting noises by precluding scattering of the exhaust sound from the suction system. CONSTITUTION: A silencer 14 is furnished in an EGR pipe 10 tying the exhaust side of an engine 1 with the suction side, and thereby the exhaust sound of the exhaust gas on the way of returning to the suction side from the exhaust side through the EGR pipe 10 is silenced, and thus scattering of the exhaust sound from the suction system is precluded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EGR device.

[0002]

2. Description of the Related Art Generally, in an engine of an automobile, a part of exhaust gas discharged from an exhaust line of the engine is taken into the intake air of the engine through an exhaust gas recirculation path by utilizing a pressure difference between the exhaust line and the intake line. Exhaust gas recirculation (Exhaust Gas Recirc) that reduces the generation of NOx by suppressing the combustion of fuel in the engine by the exhaust gas returned to the intake line and returned to the intake line
is being performed.

An example of an EGR device conventionally used for exhaust gas recirculation will be described with reference to FIG. 18. An intake manifold 2 is attached to an intake side of an engine 1 and an exhaust manifold is provided to an exhaust side of the engine 1. 3 is attached. An intake pipe 5 having an air cleaner 4 is connected to the intake manifold 2, and an exhaust pipe 6 is connected to the exhaust manifold 3.

The intake air 7 to the engine 1 passes through an air cleaner 4 and an intake pipe 5, is supplied from the intake manifold 2 to the engine 1 and is mixed with fuel and burned. It is designed to be discharged as 8.

An EGR valve 9 is provided between the exhaust pipe 6 on the exhaust side of the engine 1 and the intake pipe 5 on the intake side of the engine 1 as a device for performing exhaust gas recirculation for reducing the generation of NOx. With EGR
A pipe 10 is provided, and a part of the exhaust gas 8 is returned from the exhaust pipe 6 to the intake pipe 5 through the EGR pipe 10 to suppress the combustion of the fuel in the engine 1 to lower the combustion temperature and reduce the generation of NOx. I am able to do so.

The EGR valve 9 is a valve that opens when exhaust gas recirculation is performed and closes when exhaust gas recirculation is not performed, and exhaust gas recirculation is performed by the control device 13 to which the engine speed 11 and the load 12 are input. It is a valve that opens and closes in response to a signal from the control device 13 when the operating state of whether or not it should be made is determined.

[0007]

In the case of a small vehicle, the engine 1 is small and the EGR pipe 10 has a small diameter, so no noise is produced so much. However, in the case of a large vehicle, the engine 1 is large and the EGR pipe 10 has a diameter of 30 mm. When the exhaust gas 8 returns to the intake pipe 5 side through the EGR pipe 10, the exhaust sound is radiated from the intake system to cause noise.

An object of the present invention is to provide an EGR device which solves the above-mentioned conventional problems and does not generate noise.

[0009]

A first aspect of the present invention is an EGR device having an EGR valve in the middle of an EGR pipe connecting an exhaust side and an intake side of an engine, wherein a silencer is provided in the EGR pipe. The present invention relates to a characteristic EGR device, and a second invention is an EGR device in which an EGR valve is provided in the middle of an EGR pipe connecting an exhaust side and an intake side of an engine, and a silencer chamber is connected to the intake side of the engine. According to a third aspect of the present invention, there is provided an EGR device which connects an exhaust side and an intake side of an engine.
The present invention relates to an EGR device having an EGR valve provided in the middle of the pipe, wherein a valve whose opening can be adjusted is provided near a portion connected to the intake side of the EGR pipe. .

[0010]

In the first aspect of the invention, the exhaust noise in the exhaust returning from the exhaust side to the intake side through the EGR pipe is silenced by the silencer provided in the EGR pipe, and the exhaust noise is no longer emitted from the intake system.

In the second aspect of the invention, the pulsation in the EGR pipe is canceled by the reflected wave of the muffling chamber on the intake side, and the exhaust sound is no longer emitted from the intake system.

In the third aspect of the invention, the valve provided in the EGR pipe serves as a throttle to reduce the pulsation in the EGR pipe, and the exhaust sound is not emitted from the intake system.

[0013]

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

FIG. 1 is a schematic configuration diagram of an engine provided with an EGR device according to the first aspect of the present invention. The same parts as those in FIG. 18 are designated by the same reference numerals.

The invention of claim 1 is, as shown in FIG. 1, an exhaust manifold 3 on the exhaust side of the engine 1, and
The EGR pipe 10 connecting the intake manifold 2 on the intake side of the engine 1 is provided with a silencer 14.

As a result, the pulsation of the exhaust gas that has entered the EGR pipe 10 from the exhaust side exhaust manifold 3 is attenuated by the silencer 14, and the exhaust sound is not emitted from the intake side intake manifold 2 so that no noise is generated. become.

As the muffler 14, a number of embodiments can be provided.

FIG. 2 is a silencer 14 according to the invention of claim 1.
2 is an enlarged cross-sectional view of the first embodiment of FIG.
The outer case 15 is attached to the outside of the EGR pipe 10 in a hermetically sealed manner by welding or the like, and the outer case 15 of the EGR pipe 10 is
A large number of small holes 16 are formed in a portion penetrating the inside of the EGR pipe, and a space between the outer case 15 and the EGR pipe 10 is filled with a sound absorbing material 17 such as glass wool.
The pulsation of the exhaust gas that has entered the pipe 10 passes through the small holes 16 and is absorbed by the sound absorbing material 17.

FIG. 3 is a silencer 14 according to the invention of claim 1.
2 is an enlarged cross-sectional view of the second embodiment of FIG.
A distant portion 18 is provided on the way, an outer case 15 is attached to the outside of the EGR pipe 10 in a hermetically sealed manner by welding or the like across the distant portion 18, and a sound absorbing material 17 is provided on the inner surface of the outer case 15 to pulsate the exhaust Is adapted to be absorbed by the sound absorbing material 17, and is suitable when foam metal, foam glass or the like is used as the sound absorbing material 17.

FIG. 4 is a silencer 14 according to the invention of claim 1.
FIG. 7 is an enlarged cross-sectional view of the third embodiment of FIG.
The outer case 15 is attached to the outside of the EGR pipe 10 in a hermetically sealed manner by welding or the like, and the outer case 15 of the EGR pipe 10 is
A large number of holes 19 are formed in a portion penetrating the inside of the outer case 15 and a space is provided between the outer case 15 and the EGR pipe 10, and exhaust pulsation is a space. It is designed to be attenuated inside.

FIG. 5 is a silencer 14 according to the invention of claim 1.
6 is an enlarged cross-sectional view of the fourth embodiment of FIG. 6, and FIG. 6 is a VI-VI cross-sectional view of FIG. 5, in which the silencer 14 is located at a location where the EGR pipe 10 is connected to the intake manifold 2. The casing 20 of the silencer 14 is formed integrally with the intake manifold 2, and a flange 21 is integrally fixed to the intake side end of the EGR pipe 10 by welding or the like. It is designed to be fixed at 20.

At the center of the casing 20, there is provided a connecting tube 23 projecting from the intake manifold 2 and having a base end side communicating with the intake manifold 2. As described above, the flange 21 is attached to the casing 20 with the bolt 22. When fixed, the tip end side of the connecting cylinder 23 comes into close contact with the end portion of the EGR pipe 10.

On the side surface on the tip side of the connecting tube 23, the connecting tube 2
A plurality of sound absorbing holes 24 that are long in the axial direction of 3 are formed, and a sound absorbing chamber 25 is formed between the connection cylinder 23 and the casing 20.

In the apparatus shown in FIGS. 5 and 6, the pulsation of the exhaust gas in the EGR pipe 10 enters the sound absorbing chamber 25 through the sound absorbing hole 24 and becomes a space.
Decay within.

FIG. 7 is a silencer 14 according to the invention of claim 1.
It is an expanded sectional view of the fifth embodiment of, EGR pipe 10
A separation portion 18 is provided on the way, and the outer case 15 is attached to the outside of the EGR pipe 10 in a hermetically sealed manner by welding or the like across the separation portion 18, and the entire inside of the outer case 15 is a sound absorbing chamber 25. Exhaust pulsation in the EGR pipe 10 is attenuated in the sound absorbing chamber 25.

FIG. 8 is a silencer 14 according to the invention of claim 1.
9 is an enlarged cross-sectional view of the sixth embodiment, in which the same parts as those in FIG. 7 are designated by the same reference numerals.

In the embodiment shown in FIG. 8, the central axes of the left and right EGR pipes 10 separated by the separating portion 18 are displaced by a distance A, and the pulsation of exhaust gas in the EGR pipe 10 is damped in the sound absorbing chamber 25. To do.

FIG. 9 is a silencer 14 according to the first aspect of the invention.
7 is an enlarged cross-sectional view of the seventh embodiment, in which the same parts as those in FIG. 7 are designated by the same reference numerals.

In the embodiment shown in FIG. 9, one of the left and right EGR pipes 10 which is separated by the separating portion 18 is bent on the insertion side of the outer case 15 so that the left and right EGs are inside the sound absorbing chamber 25.
The RGR 10 is attached to the outer case 15 so that the central axis of the R pipe 10 has an angle θ.
The pulsation of the exhaust during 0 is damped in the sound absorption chamber 25.

FIG. 10 is a silencer 1 according to the invention of claim 1.
8 is an enlarged sectional view of an eighth embodiment of No. 4, in which the same parts as those in FIG. 7 are designated by the same reference numerals.

In the embodiment shown in FIG. 10, a separator 27 having a through hole 26 is provided inside the outer case 15 to divide the sound absorbing chamber 25 into two, and the left and right EGR pipes are separated by a separating portion 18. The central axis of 10 is shifted, and the distance B between the central axis of one EGR pipe 10 and the central axis of the through hole 26, and the central axis of the other EGR pipe 10 and the central axis of the through hole 26. Since the distance C is different, the pulsation of exhaust gas in the EGR pipe 10 is attenuated in the two sound absorbing chambers 25.

FIG. 11 is a silencer 1 according to the invention of claim 1.
FIG. 11 is an enlarged cross-sectional view of the fourth embodiment of FIG. 4, in which the same parts as those in FIG. 10 are designated by the same reference numerals.

In the embodiment shown in FIG. 11, a separator 27 having an inner pipe 28 penetrating inside the outer case 15 is used.
Is provided to divide the sound absorbing chamber 25 into two, and the central axis lines of the left and right EGR pipes 10 which are separated by the separated portion 18 are arranged in a straight line, and the two sound absorbing chambers 25 are communicated with each other by an inner pipe 28. Exhaust pulsations in the pipe 10 are damped in the two sound absorption chambers 25.

FIG. 12 is a silencer 1 according to the invention of claim 1.
FIG. 12 is an enlarged cross-sectional view of the fourth tenth embodiment, in which the same parts as those in FIG. 11 are designated by the same reference numerals.

In the embodiment shown in FIG. 12, a separator 27 having an inner pipe 28 penetrating inside the outer case 15 is used.
Is provided horizontally, and the inside of the outer case 15 is divided into two upper and lower sound absorbing chambers 25, and one central axis of the left and right EGR pipes 10 and the central axis of the inner pipe 28, which are separated by the spacing portion 18, form an angle β. And the central axis of the other EGR pipe 10 and the central axis of the inner pipe 28 intersect at an angle γ.
Exhaust pulsation in the pipe 10 is due to the two sound absorption chambers 2
Decays within 5.

In the embodiment shown in FIGS. 10 to 12, the number of the separators 27 installed may be two or more, and the sound absorbing chambers 25 may be three or more.

FIG. 13 is a silencer 1 according to the invention of claim 1.
FIG. 14 is an enlarged cross-sectional view of the eleventh embodiment of FIG. 4, in which two orifices 29 are attached at intervals in the middle of the EGR pipe 10, and the silencer 14 is provided between the two orifices 29.
Of the exhaust gas in the EGR pipe 10 is damped between the two orifices 29.

FIG. 14 is a silencer 1 according to the invention of claim 1.
It is a schematic block diagram of the EGR apparatus provided with the 4th 12th Example, and attaches | subjects the same code | symbol to the same part as FIG.

In the embodiment shown in FIG. 14, the muffling chamber 30 is arranged close to the EGR pipe 10, and the passage 3 having the valve 31 is provided.
In FIG. 2, the muffler chamber 30 and the EGR pipe 10 are connected to form a muffler 14, and a signal from the control device 13 to which the engine speed 11 and the load 12 are input allows the EGR valve 9 to operate.
At the same time, the valve 31 is also opened and closed.

In the embodiment shown in FIG. 14, when exhaust gas recirculation is performed, the valve 31 is opened to guide the pulsation of the exhaust gas in the EGR pipe 10 to the muffling chamber 30 and attenuate the exhaust gas recirculation state. When the exhaust sound is not emitted from the intake system, the valve 31 is closed to shut off the muffling chamber 30 from the EGR pipe 10.

FIG. 15 is a schematic block diagram of an embodiment of the invention of claim 2 and the same parts as those in FIG. 18 are designated by the same reference numerals.

In the embodiment shown in FIG. 15, an exhaust pipe 6 on the exhaust side of the engine 1, an intake pipe 5 on the intake side of the engine 1 and an EGR valve 9 are provided.
The GR pipe 10 is connected to connect the muffler chamber 33 to the intake pipe 5 on the intake side of the engine 1.
The pulsation of the exhaust gas at 0 is guided to the muffling chamber 33 so as to be attenuated.

The muffling chamber 33 may have a constant volume,
As shown in FIG. 16, a piston 34 can be slidably provided inside the muffling chamber 33 so that the volume inside the muffling chamber 33 can be adjusted.

In this case, a rack 36 is provided on the piston rod 35 of the piston 34, and a pinion 38 rotated by a step motor 37 is meshed with the rack 36. Then, an effective frequency is calculated by the control device 13 to which the engine speed 11 and the load 12 are input, the volume of the muffling chamber 33 that resonates at the frequency is calculated, the step motor 37 is operated, and the muffling chamber 33 becomes The piston 34 is moved so as to have an appropriate volume.

Most of the sound source of noise during EGR operation is the explosion sound of the engine 1, and the engine explosion sound can be almost estimated by the engine speed. Therefore, by controlling the volume of the muffling chamber 33 by the engine speed, it is possible to change the phase of the reflected wave generated in the muffling chamber 33 and cancel the pulsation propagating immediately before the muffling chamber 33.

FIG. 17 is a schematic configuration diagram of an embodiment of the invention of claim 3, and the same parts as those of FIG. 18 are denoted by the same reference numerals.

In the embodiment shown in FIG. 17, an exhaust pipe 6 on the exhaust side of the engine 1, an intake pipe 5 on the intake side of the engine 1 and an EGR valve 9 are provided.
A valve 39 whose opening can be adjusted is provided near the point where the GR pipe 10 is connected and the EGR pipe 10 is connected to the intake pipe 5 on the intake side, and the engine speed 11 and the load 12 are input. Valve 39 by device 13
The opening degree of is adjusted.

When exhaust gas recirculation is performed in this apparatus, if the control device 13 causes the valve 39 to be slightly closed, the valve 39 acts as a throttle to reduce the pulsation of the exhaust gas in the EGR pipe 10, and thus noise is generated. It will be attenuated.

Further, when the accelerator 13 is depressed to increase the rotational speed of the engine 1, the control device 13 causes the valve 39 to be fully closed.
The exhaust gas 8 remaining in the exhaust gas will not be discharged from the exhaust pipe 6 through the EGR valve 9 and flow into the engine 1, so that an air shortage is less likely to occur.
Less black smoke is generated.

The EGR device of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0051]

According to the invention of claim 1, E from the exhaust side
Exhaust noise in the exhaust that returns to the intake side through the GR pipe is EG
The muffler provided on the R pipe muffles the exhaust sound so that the exhaust sound is not emitted from the intake system, and the noise emitted by the EGR device is reduced.

According to the second aspect of the invention, the pulsation in the EGR pipe is canceled by the reflected wave of the muffling chamber on the intake side,
Exhaust noise is not radiated from the intake system, noise radiated by the EGR device can be reduced, and optimum silencing can be performed by changing the volume of the silencing chamber.

According to the third aspect of the present invention, the valve provided in the EGR pipe serves as a throttle to reduce the pulsation in the EGR pipe, and the exhaust sound is no longer emitted from the intake system and is emitted by the EGR device. Less noise,
Further, there is an effect that black smoke generation at the time of engine acceleration can be reduced.

[Brief description of drawings]

FIG. 1 is a side view of an engine provided with an EGR device according to a first aspect of the invention.

FIG. 2 is an enlarged cross-sectional view of a muffler according to the first embodiment of the invention.

FIG. 3 is an enlarged sectional view of a second embodiment of the silencer according to the invention of claim 1.

FIG. 4 is an enlarged cross-sectional view of a silencer according to a third embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a silencer according to a fourth embodiment of the invention.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is an enlarged sectional view of a silencer according to a fifth embodiment of the invention.

FIG. 8 is an enlarged sectional view of a silencer according to a sixth embodiment of the present invention.

FIG. 9 is an enlarged sectional view of a silencer according to a seventh embodiment of the invention of claim 1.

FIG. 10 is an enlarged cross-sectional view of an eighth embodiment of the silencer according to the invention of claim 1.

FIG. 11 is an enlarged sectional view of a silencer according to a ninth embodiment of the invention of claim 1.

FIG. 12 is an enlarged sectional view of a silencer according to a tenth embodiment of the present invention.

FIG. 13 is an enlarged cross-sectional view of an eleventh embodiment of the silencer according to the invention of claim 1.

FIG. 14 is a schematic configuration diagram of an EGR device including a silencer according to a twelfth embodiment of the present invention.

FIG. 15 is a schematic configuration diagram of an embodiment of the invention of claim 2;

FIG. 16 is an enlarged sectional view of an essential part of another embodiment of the invention according to claim 2;

FIG. 17 is a schematic configuration diagram of an embodiment of the invention of claim 3;

FIG. 18 is a schematic configuration diagram of an engine provided with a conventional EGR device.

[Explanation of symbols]

 1 Engine 2 Intake Manifold 3 Exhaust Manifold 5 Intake Pipe 6 Exhaust Pipe 9 EGR Valve 10 EGR Pipe 14 Silencer 33 Silencer Chamber 39 Valve

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02M 35/10 311 F02M 35/10 311E 35/12 35/12 C

Claims (3)

[Claims] 1. An EG connecting an exhaust side and an intake side of an engine
An EGR device having an EGR valve in the middle of an R pipe, wherein a silencer is provided in the EGR pipe. 2. An EG connecting an exhaust side and an intake side of an engine
An EGR device having an EGR valve provided in the middle of an R pipe, wherein a muffling chamber is connected to the intake side of the engine. 3. An EG connecting an exhaust side and an intake side of an engine
An EGR device having an EGR valve in the middle of an R pipe, characterized in that a valve whose opening can be adjusted is provided near a portion connected to the intake side of the EGR pipe.