JP2001193575A - Exhaust reflux device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To distribute equally a mixture uniformly mixed of EGR gas with air into each intake branch of an intake manifold for canceling variations of the mixture in each cylinder to increase distribution performance and to increase exhaust performance in an exhaust reflux device for internal combustion engine. SOLUTION: Intake branches corresponding to cylinders successive in intake time respectively are connected facingly with each other to be mounted on each side wall part directing to each cylinder row direction for a surge tank. A throttle body mounting part to mount a throttle body is mounted on upper part of center of the surge tank. Each branch connecting hole to connect with each intake branch is formed on each side wall part of the surge tank such that distance from center of the throttle body of the throttle body mounting part to each place where each intake branch is connected with is the same respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exhaust gas recirculation system for an internal combustion engine, and more particularly to an exhaust gas recirculation system for an internal combustion engine that recirculates a part of exhaust gas to an intake manifold.

[0002]

2. Description of the Related Art A multi-cylinder internal combustion engine mounted on a vehicle is provided with a throttle body for adjusting the amount of intake air and an intake manifold for introducing intake air to each cylinder in order to guide intake air to a plurality of cylinders. Further, the internal combustion engine is provided with an exhaust gas recirculation device (EGR device) that recirculates a part of the exhaust gas from the exhaust system to the intake manifold to reduce the combustion temperature in the combustion chamber and reduce exhaust harmful components such as NOx. ing.

That is, as shown in FIGS. 11 to 13, in an internal combustion engine 102 having a plurality of cylinders (for example, four cylinders) arranged in series, an intake manifold mounting flange 106 mounted on a side surface of a cylinder head 104 and each of the cylinders (Four) first to fourth intake branches 108 corresponding to
-1 to 108-4 and surge tank 1 for suppressing intake pulsation
10 is provided, and a throttle valve 114 is provided at one end of the surge tank 110.
Is attached. Further, an EGR valve 120 is attached to the side surface on the fourth intake branch 108-4 side so as to constitute the exhaust gas recirculation device 118, and the EGR valve 120 has a one-side joint 1
The other end of the EGR pipe 124 is connected to the other end 12
It is attached to the surge tank 110 via 2-2.

In the exhaust gas recirculation device 118,
As shown in FIG. 12, various signals such as a throttle opening from a throttle sensor 126 attached to the throttle body 116 and a cooling water temperature from a temperature sensor 128 attached to the intake manifold 112 are input to a control means 130. 130 controls the amount of EGR gas, which is exhaust gas to be recirculated by operating the EGR valve 120.

[0005] Such an exhaust gas recirculation device for an internal combustion engine is disclosed in, for example, JP-A-10-89159 and JP-A-9-159.
No. 3,317,569 and JP-A-6-173782. Japanese Patent Application Laid-Open No. 10-89159 discloses a synthetic resin intake manifold in which a notch is formed at an opening edge of an exhaust gas recirculation pipe insertion hole to an intake manifold to prevent thermal damage. is there. JP 9
Japanese Patent Publication No.-317569 discloses a gas recirculation pipe in which a central axis of a connection end is located in a plane perpendicular to a central axis of an inner pipe to improve mixing and distribution. It is. Japanese Unexamined Patent Publication No. 6-173782 discloses that an EGR passage is disposed on a vehicle front side of an intake collecting portion,
This improves the intake charging efficiency.

[0006]

Conventionally, in an exhaust gas recirculation system for an internal combustion engine, it is important to mix the EGR gas and air from the throttle body side in order to optimally control the amount of the EGR gas. .

For this reason, it is desirable that the EGR gas and the air are uniformly mixed, and that the air-fuel mixture is evenly distributed to each cylinder. However, as shown in FIG. First connected to surge tank 110
The first to fourth centers Q of the first to fourth tank side connection ports 132-1 to 132-4 of the first to fourth intake branches 108-1 to 108-4
Since the first to fourth distances L1 to L4 from 1 to Q4 are different from each other, that is, from the first distance L1 to the fourth distance L
Since the distance gradually increases toward the fourth side, the EGR gas and the air are mixed so as to collide with each other at the first tank side connection port 132-1 side.
On the 32-4 side, the EGR gas and the air are mixed on the way, so that a uniform air-fuel mixture cannot be evenly distributed to each cylinder. Further, on the fourth tank side connection port 132-4 side, since the EGR gas is located near the wall surface where the flow velocity becomes slow in the tank chamber 134, there is a problem that it becomes difficult to distribute the EGR gas more evenly.

In order to solve this problem, as shown in FIG. 14, the distal end portion 124A of the EGR pipe 124 is extended to the central portion of the tank chamber 134 where the flow velocity is high to improve the mixing of the EGR gas and air. . Further, as shown in FIG. 15, the distal end 124A of the EGR pipe 124 has
Although the inclined surface 136 is formed by processing or the distribution hole 138 is formed by processing as shown in FIG. 16, such special processing increases the cost and the uniform mixing is insufficient. There was an inconvenience.

[0009]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides a plurality of intake branches corresponding to a plurality of cylinders arranged in series in an internal combustion engine and a surge tank for suppressing intake pulsation. In the exhaust gas recirculation device for an internal combustion engine that provides an intake manifold having: and a part of the exhaust gas that recirculates to the intake manifold, the surge tank has a continuous intake timing on each side wall portion directed to each side in the cylinder row direction. The intake branches corresponding to the cylinders to be connected are provided so as to face each other in the cylinder row direction, and a throttle body mounting portion for mounting a throttle body is provided at the upper center of the surge tank. From each other to connect each of the intake branches so as to be at the same distance from each of the sections to which each of the intake branches is connected. The wrench connection port, characterized in that provided on each side wall of the surge tank.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a surge tank in which intake branches corresponding to cylinders having successive intake timings are connected to respective side wall portions directed to respective sides in the cylinder row direction so as to face each other in the cylinder row direction. A throttle body mounting part for mounting the throttle body is provided at the upper center of the surge tank.Each intake branch is located at the same distance from the center of the throttle body of this throttle body mounting part to each point where each intake branch is connected. Is provided on each side wall of the surge tank, so that the air-fuel mixture in which the EGR gas and the air are uniformly mixed can be evenly distributed to each intake branch. The air-fuel mixture does not vary, and the air-fuel mixture is distributed uniformly, thereby improving the distribution performance and improving the exhaust performance.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 7 show a first embodiment of the present invention. 6 and 7, 2 is a vehicle,
4 is for multiple cylinders (for example, 4 cylinders: # 1, # 2, # 3, #
4) An internal combustion engine, 6 is a transmission, 8 is a front wheel, 10 is a cylinder head, and 12 is a cylinder head cover. The cylinder head cover 12 has a lubrication port 14 and a DLI (distributorless ignition coil) cover 16.
Are provided.

An intake manifold 18 is attached to one side surface (rear side of the vehicle) of the cylinder head 10 in an intake system. Further, first to fourth fuel injection valves 20-1 to 20-4 are fixedly provided at an upper portion of the cylinder head 10, and the first to fourth fuel injection valves 20-1 to 20-4 are provided.
A fuel delivery pipe 22 is provided with pipe mounting bolts 24. A fuel pipe 28 is connected to the fuel delivery pipe 22 via a pipe connection 26.

On the other side (front side of the vehicle) of the cylinder head 10, an exhaust manifold 30 and an exhaust manifold cover 3 that covers the exhaust manifold 30 in an exhaust system.
2 are provided.

The intake manifold 18 is provided for the cylinder head 1.
0, the intake manifold mounting flange 34 attached to one side surface (rear side of the vehicle), the first to fourth intake branches 36-1 to 36-4 corresponding to each cylinder, and a surge tank 38 for suppressing intake pulsation. Have been.

The intake manifold mounting flange 34 is formed in a plate shape that is long in the cylinder row direction X.

The surge tank 38 has one side wall 40 and 42 facing each side in the cylinder row direction X, and the opposing wall 4 opposing and facing the intake manifold mounting flange 34.
4. A tank space 52 is formed by the back wall portion 46, the lower bottom portion 48, and the upper ceiling portion 50 to form a substantially hollow rectangular parallelepiped.

In the surge tank 38, a throttle body mounting portion 54 is provided on a ceiling portion 50, and an air intake 56 is provided at a central upper portion of the throttle body mounting portion 54. In the throttle body mounting portion 54, a recirculation exhaust gas mixing chamber 58 communicating with the tank space 52 in the surge tank 38 is formed with a height H and a diameter D. A throttle body 64 is mounted on a mounting surface 60 which is an upper surface of the throttle body mounting portion 54 via a gasket 62.

First to fourth intake branches 36-1 to 36-4
Represents the cylinder row direction X corresponding to the cylinders having successive intake timings.
Are connected to the other side walls 40 and 42 facing each other in the cylinder row direction X. That is, first,
The second intake branches 36-1 and 36-2 are provided on one side wall portion 40.
, And the third and fourth intake branches 36-3 and 36-4 are connected in parallel to the other side wall portion 42. In this case, as shown in FIG. 1, the first and second intake branches 36-1 to 36-4 are connected at the same distance L from the throttle body center C of the throttle body mounting portion 64 to each of the connecting points. 1-4 branch connection port 66-
1 to 66-4 are formed on one side and the other side wall portions 40 and 42. That is, the center C of the throttle body and the first to fourth centers Q1 to Q4 of the first to fourth branch connection ports 66-1 to 66-4.
Up to the same distance L.

The internal combustion engine 4 has an exhaust gas recirculation device 68.
Is provided. The exhaust gas recirculation device 68 recirculates EGR gas, which is a part of exhaust gas recirculated to the intake manifold 18, to the intake manifold 18, and includes an EGR passage 70 extending from the exhaust side to the intake side and And an EGR valve 72 attached to the cylinder head 10 in the middle of the operation. The EGR passage 70 includes an exhaust-side EGR passage 74 formed in the exhaust manifold 30, a head-side EGR passage 76 formed in the cylinder head 10 in communication with the exhaust-side EGR passage 74, and a head-side EGR.
A pipe-side EGR passage 80 formed by an EGR pipe 78 communicating with the passage 76 is provided.

Further, the intake manifold 18 is formed with an exhaust introduction passage 82 which communicates the pipe side EGR passage 80 with the recirculation exhaust gas mixing chamber 58. This exhaust introduction passage 82
Are a pipe-side exhaust introduction passage 82-1 communicating with the pipe-side EGR passage 80 and directed in the cylinder row direction X, and a chamber-side exhaust communicating with the recirculation exhaust mixing chamber 58 and directed in a direction orthogonal to the cylinder row direction X. And an introduction passage 82-2. In the chamber side exhaust introduction passage 82-2, an inflow port 82A opening to the recirculation exhaust gas mixing chamber 58 introduces the EGR gas into the throttle body center C in consideration of the inertia force of the EGR gas as the exhaust gas to be introduced. It is disposed on the side with a distance G offset. As a result, the inlet 82A of the chamber-side exhaust introduction passage 82-2 is arranged near the air inlet 56 as the vicinity of the throttle bore.

Next, the operation of the first embodiment will be described.

The EGR gas from the exhaust side is supplied to the EGR passage 7
0 through the exhaust gas introduction passage 82 to the recirculation exhaust gas mixing chamber 58, where the throttle body 64
It mixes with air from the side to form a mixture. At this time, EG
Due to the presence of the recirculated exhaust gas mixing chamber 58, the R gas and air
A uniform mixture is obtained. Then, this air-fuel mixture is distributed toward the first to fourth branch connection ports 66-1 to 66-4 located at the same distance L from the throttle body center C, and the first to fourth intake branches 36-1 to 36-1. It is supplied to each cylinder from 36-4.

As a result, the mixing state of the EGR gas and air in each cylinder does not vary, and a uniform air-fuel mixture can always be distributed to each cylinder. Performance can be improved.

Further, since the exhaust gas mixing chamber 58 is formed in the throttle body mounting portion 54, the EGR gas and the air can be mixed well, thereby producing a uniform air-fuel mixture and improving the exhaust performance. .

Further, the inflow port 82A of the chamber side exhaust introduction passage 82-2 is exhausted with respect to the center C of the throttle body.
Deviation (offset) by the distance G to the side where the GR gas is introduced
Since the inlet 82A of the chamber-side exhaust gas introduction passage 82-2 can be disposed near the air intake 56, especially when the straight portion of the room-side exhaust gas introduction passage 82-2 is relatively short. , Since the introduced EGR gas has inertia,
Mixing is not affected by the flow velocity distribution when the internal combustion engine 2 is rotating at a low speed or at a high speed.

FIG. 8 shows a special structure of the present invention.
It shows an embodiment.

In the following embodiments, portions having the same functions as those in the above-described first embodiment will be described with the same reference numerals.

The features of the second embodiment are as follows. That is, the chamber-side exhaust gas introduction passage 82-2 is disposed so as to be oriented in the tangential direction of the recirculation exhaust gas mixing chamber 58.

According to the structure of the second embodiment, the EGR gas is swirled in the recirculation / exhaust gas mixing chamber 58 to improve the mixing state of the EGR gas and the air and to sufficiently achieve the uniformity of the air-fuel mixture. it can.

FIGS. 9 and 10 show a special configuration of the present invention, and show a third embodiment.

The features of the third embodiment are as follows. That is, on the bottom 48 in the surge tank 38, a rotation distributor 94 rotatably supported by a shaft 92.
Was provided. The rotary distributor 94 is formed in a substantially pyramid shape, and has first to fourth distribution curved surfaces 96-1 to 96-4.

According to the structure of the third embodiment, the mixture is evenly guided to the first to fourth branch connection ports 66-1 to 66-4 by the rotation of the rotary distributor 94, and the mixture is further distributed. Performance can be improved.

[0033]

As is apparent from the above description, according to the present invention, the surge tank is provided with the intake branches corresponding to the cylinders having successive intake timings on the respective side wall portions directed to the respective sides in the cylinder row direction. A throttle body mounting portion for mounting a throttle body is provided at the upper center of the surge tank, and is provided from the center of the throttle body mounting portion to each location to which each intake branch is connected. By providing each branch connection port connecting each intake branch at the same distance on each side wall of the surge tank, an air-fuel mixture in which EGR gas and air are uniformly mixed is uniformly supplied to each intake branch. The mixture can be distributed, there is no variation in the mixture in each cylinder, and the mixture is distributed uniformly, improving the distribution performance. It can improve the care performance.

[Brief description of the drawings]

FIG. 1 is a partial plan view of an intake manifold.

FIG. 2 is a cross-sectional view of the intake manifold taken along line 2-2 of FIG.

FIG. 3 is a plan view of an intake manifold.

FIG. 4 is a side view of the intake manifold according to arrow 4 in FIG. 3;

FIG. 5 is a perspective view of an exhaust gas recirculation device.

FIG. 6 is a plan view of the engine.

FIG. 7 is a partial plan view of the vehicle.

FIG. 8 is a partial plan view of an intake manifold in a second embodiment.

FIG. 9 is a perspective view of a rotary distributor in a third embodiment.

FIG. 10 is a partial plan view of an intake manifold provided with a rotation distributor in a third embodiment.

FIG. 11 is a perspective view of a conventional exhaust gas recirculation device.

FIG. 12 is a system configuration diagram of a conventional exhaust gas recirculation device.

FIG. 13 is a plan view of a conventional intake manifold.

FIG. 14 is a plan view of an intake manifold in which a distal end side of an EGR pipe is conventionally extended into a tank chamber.

FIG. 15 is a side view of a conventional EGR pipe in which a distal end side is obliquely cut away.

FIG. 16 is a side view in which a distribution hole is conventionally formed on the distal end side of an EGR pipe.

[Explanation of symbols]

 2 Vehicle 4 Internal combustion engine 18 Intake manifold 30 Exhaust manifold 36 Intake branch 38 Surge tank 54 Throttle body attachment part 56 Air intake 58 Recirculation / exhaust mixing chamber 64 Throttle body 68 Exhaust recirculation device 70 EGR passage 82 Exhaust introduction passage

Claims (3)

[Claims] An intake manifold having a plurality of intake branches corresponding to a plurality of cylinders arranged in series with an internal combustion engine and a surge tank for suppressing intake pulsation is provided, and a part of exhaust gas is recirculated to the intake manifold. In the exhaust gas recirculation device for an internal combustion engine, the surge tank is connected to each side wall portion directed to each side in the cylinder row direction so that the intake branches corresponding to the cylinders having successive intake timings are opposed to each other in the cylinder row direction. A throttle body mounting portion for mounting a throttle body is provided at the upper center of the surge tank, and the throttle body mounting portion is provided with the same distance from the center of the throttle body to each of the points where the intake branches are connected. Each branch connection port for connecting each intake branch is provided on each side wall of the surge tank. Exhaust recirculation device for fuel engines. 2. The exhaust gas recirculation device for an internal combustion engine according to claim 1, wherein a recirculation exhaust gas mixing chamber communicating with a tank space in the surge tank is formed in the throttle body mounting portion. 3. The exhaust manifold according to claim 1, wherein an inlet opening to the recirculation / exhaust gas mixing chamber is provided with an exhaust introduction passage deflected to a side for introducing exhaust with respect to a center of the throttle body. 3. The exhaust gas recirculation device for an internal combustion engine according to 2.