JP2000008968A - Internal combustion engine exhaust gas recirculation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To aim at the avoidance of thermal deformation in a manifold, the equal distribution of EGR gas, and a reduction in weight and cost by no use of an EGR pipe, etc., in a internal combustion engine exhaust gas recirculation system with a resin inlet manifold. SOLUTION: A resin inlet manifold 3 is connected to a cylinder head 2 via a metal space 5 and a gasket 6, and this head is formed with an EGR gas suction passage 9 and three EGR gas discharge passages 10-1, 10-2 and 10-3. One end of this gas suction passage is opened to an exhaust port 12-3, and the other end is opened to an aggregate chamber formed in a connected surface 2a with the inlet manifold of the head, and an EGR valve 11 is installed in the midway. The gasket is formed with a gas common communicating port and a gas branch communicating port, and in the spacer, an EGR gas branch passage communicating to the gas common communicating port and the EGR gas branch communicating port and equal in length is groovedly formed on the connecting surface with the gasket. Gas sucked from an exhaust port is discharged to suction ports 20-1, 20-2 and 20-3 by through these passages, aggregate chambers and openings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas recirculation system for an internal combustion engine having a resin-made intake manifold, in particular, to avoid thermal deformation of the intake manifold and EGR to each cylinder.
The present invention relates to an exhaust gas recirculation device for an internal combustion engine that achieves equal distribution of gas and the like.

[0002]

2. Description of the Related Art Generally, in an exhaust gas recirculation system for an internal combustion engine, recirculated EGR gas is taken out from an exhaust port or an exhaust manifold of a cylinder head, passes through an EGR valve, and is supplied to a surge tank or an intake manifold of an intake manifold downstream of a throttle valve. It is structured to be discharged into the passage.

In an exhaust gas recirculation device having such a structure,
When the intake manifold is formed of a resin material, a heat insulating material is attached to the intake manifold, a heat dissipation structure is provided, or a cooling system is incorporated in order to prevent thermal deformation due to high temperature EGR gas ( Japanese Utility Model Publication No. 4-5720, Japanese Unexamined Patent Publication No. 6-101587,
See Japanese Utility Model Publication No. 5-40294).

[0004]

However, in the prior art, since high-temperature EGR gas is directly discharged to the intake manifold, it is difficult to avoid thermal deformation and thermal deterioration. However, if a special member, structure, or system is to be incorporated, an increase in weight and cost due to the addition of additional parts occurs, and the number of maintenance items increases.

Further, when the EGR gas is discharged to the surge tank of the intake manifold, there has been a problem that condensed water of steam in the EGR gas stays there and accumulates.

The present invention solves the above-mentioned problems, avoids thermal deformation and thermal deterioration of the resin-made intake manifold due to EGR gas, and retains EGR gas condensed water in an intake passage such as a surge tank. And EG
An object of the present invention is to provide an exhaust gas recirculation device for an internal combustion engine having a simple structure capable of evenly distributing R gas to each cylinder.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an exhaust gas recirculation system for an internal combustion engine which has solved the above-mentioned problems. In an exhaust gas recirculation system for an internal combustion engine that recirculates to an intake system, a resin intake manifold is connected to a cylinder head via a metal spacer and a metal gasket, and a series of EGR gas is supplied to the cylinder head. An intake passage and a number of EGR gas discharge passages corresponding to the number of cylinders are formed, and one end of the EGR gas intake passage is
The cylinder head is opened to an exhaust port, and the other end is opened to a collecting chamber formed on a connection surface of the cylinder head with the intake manifold, and an intermediate portion of the opening passes through an EGR valve attached to the cylinder head. In the gasket, one EGR gas common communication port and a number of EGR gas branch communication ports corresponding to the number of cylinders are formed, and the spacer is provided on the joint surface with the gasket with the EGR gas. Communicating with the common communication port and the EGR gas branch communication port;
EGR gas branch passages of a number corresponding to the number of cylinders and having an equal length are formed in a groove shape, and EGR gas suctioned from the exhaust port is formed.
GR gas enters the EGR gas discharge passage through the EGR gas suction passage, the collecting chamber, the EGR gas common communication port, the EGR gas branch passage, and the EGR gas branch communication port, and the EGR gas discharge passage An exhaust gas recirculation device for an internal combustion engine, characterized in that it flows in the flow direction of intake air and is discharged from a discharge port to a suction port.

In the exhaust gas recirculation system for an internal combustion engine having a resin-made intake manifold, the EGR gas sucked from the exhaust port is supplied to the cylinder head. Through the EGR gas suction passage, the common chamber, the common EGR gas communication port of the metal gasket, the grooved EGR gas branch path of the metal spacer, and the EGR gas branch communication port of the gasket. It enters the discharge passage, flows in the EGR gas discharge passage in the flow direction of the intake air, and is discharged from the discharge port to the suction port.

As a result, the EGR gas is guided to the intake port without being directly discharged to the intake manifold by the interposition of the metal spacer and the metal gasket. Thermal degradation can be avoided, and the problem that the condensed water of the steam in the EGR gas stays and accumulates in the intake passage such as the surge tank does not occur. it can.

Further, the EGR gas passage can be easily formed in the cylinder head and the spacer without any intervening joint means such as a pipe. Moreover, the cylinder head,
Each joint between the gasket, spacer, and intake manifold can be used to form an EGR gas passage. Thus, weight reduction, cost reduction, and space saving can be achieved.

Further, since a passage (EGR gas discharge passage) immediately before the discharge of the EGR gas to the suction port is formed in the cylinder head, a large negative pressure can be obtained adjacent to the negative pressure generating source. EGR gas can be efficiently recirculated into the combustion chamber. In addition, since the EGR gas flows in the EGR gas discharge passage in the direction of the flow of the intake air, the EGR gas can be smoothly discharged to the intake port.

The EGR gas is the EGR gas of the gasket.
After passing through the common gas communication port, the gas flows through the EGR gas branch passage of the spacer. Since the EGR gas branch passages have the same length, the EGR gas can be equally distributed to each cylinder.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the invention described in claim 1 of the present application shown in FIGS. 1 to 8 will be described below. FIG. 1 is a partial elevational view of an internal combustion engine to which the exhaust gas recirculation device according to the present embodiment is applied, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is a cylinder head cover of the internal combustion engine of FIG. FIG. 4 is a side view of the cylinder head of the internal combustion engine of FIG. 1 when the connecting surface with the intake manifold side is viewed from the front, and FIG.
6 is a front view of the spacer viewed from the direction A in FIG. 3, FIG. 7 is a rear view of the spacer in FIG. 6, and FIG. 8 is a VIII- view in FIGS. VII
FIG. 2 is an enlarged cross-sectional view taken along the line I.

1 to 3, an internal combustion engine 1 to which an exhaust gas recirculation device according to the present embodiment is applied is an in-line three-cylinder internal combustion engine, and intake passages 3-1 and 3 branched into three.
-2, 3-3, the common flange portion 4 of the resin intake manifold 3 is connected to the metal spacer 5 and the metal relatively thin plate-like gasket 6 by fastening means (not shown). It is fastened and connected to the connection surface 2a of the cylinder head 2. The space between the flange portion 4 and the spacer 5 is actually sealed by a rubber-made ring having a modified cross section, but is not shown.

A side opposite to the common flange portion 4 of the intake manifold 3 is formed as a surge tank 7.
Further, it is connected to a throttle body (not shown). The throttle body is mounted on a mounting surface 8a of a throttle body mounting flange 8 on the surge tank 7 side.

Hereinafter, the configuration of the exhaust gas recirculation passage of the exhaust gas recirculation device will be described. First, as shown in FIG. 3, a series of EGR gas intake passages 9 and three EGR gas discharge passages corresponding to the number of cylinders are provided in the wall of the cylinder head 2.
10-1, 10-2, and 10-3 are respectively formed.

The EGR gas suction passage 9 is provided with an EGR valve 11 (shown in phantom lines in FIG. 3) mounted on the cylinder head 2.
It is composed of a passage portion 9a on the upstream side and a passage portion 9b on the downstream side, which are connected in series. The EGR valve 11 is attached by bolts on the same surface as the connection surface 2 a of the cylinder head 2 with the intake manifold 3, and the EGR valve 11 flows through the EGR gas suction passage 9.
The amount of gas is controlled according to the operating state of the engine.

The upstream passage portion 9 of the EGR gas suction passage 9
The base end of a is opened to one of the two branch exhaust ports constituting the exhaust port 12-3 of the third cylinder, through which exhaust gas (EGR gas) flows through the upstream passage portion. 9a. Reference numerals 12-1 and 12-2 denote exhaust ports of the first cylinder and the second cylinder, respectively.

The downstream passage portion 9 of the EGR gas suction passage 9
b is bent at a right angle at a connection portion with the EGR valve 11 and runs parallel to the connection surface 2a of the cylinder head 2, and its end is formed into an elongate depressed collecting chamber 13 (see FIG. 4) on the connection surface 2a. It is open to.

Next, as shown in FIG. 5, the gasket 6 has an elongated plate shape,
Three EGR gas communication ports 14-1, 14-2, and 14-3, one EGR gas common communication port 15 below the center first air / fuel mixture communication port 14-2, and three Small-diameter EGR gas branch communication ports 16-1, 16
-2 and 16-3 are formed by punching. The three small-diameter EGR gas branch communication ports 16-1, 16-2, and 16-3 are three
The first mixture passages 14-1, 14-2, and 14-3 are formed adjacent to the left or right, respectively.

The first mixture passages 14-1, 14-2, 14-3 and the EG
Although not shown in detail, a bead 17 is set between the R gas communication port (the EGR gas common communication port 15 and the EGR gas branch communication ports 16-1, 16-2, and 16-3). In this way, different gases flowing through these communication ports are sealed so as not to mix.

As shown in FIG. 5, the EGR gas common communication port 15 has a pot-like shape when viewed from the front, and faces the collecting chamber 13 formed on the connection surface 2a of the cylinder head 2. The EGR gas introduced into the collecting chamber 13 is guided to EGR gas branch passages 19-1, 19-2, and 19-3 (described later) of the subsequent spacer 5.

Next, as shown in FIGS. 6 and 7, the outline of the spacer 5 is substantially the same as that of the gasket 6, and three second mixture passages are provided at the left, right, and center thereof.
18-1, 18-2, and 18-3 are formed to penetrate, and these three second air-fuel mixture communication ports 18-1 and 18-3 are provided on the joint surface with the gasket 6.
Sewing between -2 and 18-3, 3 curved E of equal length
GR gas branch passages 19-1, 19-2, 19-3 are grooved (see Fig. 8)
Is formed. Each EGR gas branch passage 19-1, 19-2,
The cross-sectional area of the groove of 19-3 is made equal.

These three EGR gas branch passages 19-1,
19-2 and 19-3 are gaskets 6 at their proximal ends.
The EGR gas common communication port 15 collects in substantially the same shape as the front lid shape of the EGR gas common communication port 15, and receives the EGR gas in the collecting chamber 13 through the EGR gas common communication port 15, respectively.

The volume of the collecting chamber 13 is determined by the EG collected there.
Large enough to absorb the R gas pulsation,
The cross-sectional area is three EGR gas branch passages 19-1,
It is made larger than the sum total of the passage cross-sectional areas of 19-2 and 19-3.
The shape of the EGR gas common communication port 15 conforms to the shape of the base end gathering portion of the three EGR gas branch passages 19-1, 19-2, and 19-3, but protrudes from the shape of the base end gathering portion. It is formed in a size that does not.

The three EGR gas branch passages 19-1 and 19
-2 and 19-3 communicate with the three EGR gas branch communication ports 16-1, 16-2 and 16-3 of the gasket 6 at their end portions, respectively. EG
The R gas is supplied to these three EGR gas branch communication ports 16-1 and 16-1.
-2 and 16-3, respectively, into the three EGR gas discharge passages 10-1, 10-2 and 10-3 of the cylinder head 2.

The three EGR gas discharge passages 10-1, 10-2, 10
-3 is opened to each of the intake ports 20-1, 20-2, and 20-3 of the three cylinders, and the three EGR gas branch passages 19-
The EGR gas sent from 1, 19-2, and 19-3 is discharged to these intake ports 20-1, 20-2, and 20-3, respectively, and further from there, the combustion chamber of each cylinder (not shown) ).

Here, three EGR gas discharge passages 10-1,
As shown in FIG. 3, the cylinder heads 10-2 and 10-3 lie close to the suction ports 20-1, 20-2 and 20-3 of the three cylinders at acute angles, respectively. Is formed. Therefore, the EGR gas is supplied to the EGR gas discharge passage 10-
1, 10-2, and 10-3 flow in the direction of the flow of the intake air, and each of the intake ports 20-1, 20-2,
Smooth ejection to 20-3 is possible.

As is clear from the above description, the exhaust gas recirculation passage of the exhaust gas recirculation device according to the present embodiment includes the EGR gas intake passage 9 formed in the cylinder head 2 and the common chamber 1.
3. EGR gas common communication port 1 formed in gasket 6
5, three EGR gas branch passages 1 formed in the spacer 5
9-1, 19-2, 19-3, three Es formed on gasket 6
GR gas branch communication ports 16-1, 16-2, 16-3, three EGR gas discharge passages 10-1, 10-2 formed in the cylinder head 2,
10-3 and three EGRs formed in the cylinder head 2
The gas discharge passages 10-1, 10-2, and 10-3 are configured so as to communicate with each other in this order.

Accordingly, the EGR gas sucked from one of the branch exhaust ports 12-3 of the third cylinder flows through these passages and openings, and flows into the respective intake ports 20-1 and 20-. The fuel is discharged to the combustion chambers 2 and 20-3, and further guided to the combustion chambers of the respective cylinders, where they are recirculated.

Since the present embodiment is configured as described above, the following effects can be obtained. The EGR gas sucked from the exhaust port 12-3 is, as described above,
Each EG formed on the cylinder head 2 and the spacer 5
The gas flows through the R gas passage, passes through each opening formed in the gasket 6, is discharged to each of the suction ports 20-1, 20-2, and 20-3, and is further guided to the combustion chamber of each cylinder. It is designed to be refluxed.

As a result, the EGR gas is not directly discharged to the intake manifold 3 by the interposition of the spacer 5 and the gasket 6, and the respective intake ports 20-1, 20-2, 20-3 are not discharged.
, It is possible to avoid thermal deformation and thermal degradation of the intake manifold 3. In addition, since the condensed water of the steam in the EGR gas does not stay and accumulate in the intake passage such as the surge tank 7, the EGR gas can be quickly returned to the combustion chamber.

Further, the spacer 5 and the gasket 6
Since they are made of metal, they are not subjected to thermal deformation or thermal deterioration by the EGR gas, and do not cause any trouble in sending the intake air or the EGR gas into the combustion chamber.

Further, the EGR gas recirculation path can be easily formed in the cylinder head 2 and the spacer 5 without any intervening joint means such as a pipe. In addition, the EGR gas passage can be formed by skillfully using the respective joints between the cylinder head 2, the gasket 6, the spacer 5, and the intake manifold 3. Thus, weight reduction, cost reduction, and space saving can be achieved.

Further, each suction port port of the EGR gas
The passages (EGR gas discharge passages 10-1, 10-2, 10-3) formed immediately before discharge to 20-1, 20-2, 20-3 are formed in the cylinder head 2, so that they are adjacent to the negative pressure source. As a result, a large negative pressure can be obtained, and the EGR gas can be efficiently recirculated into the combustion chamber.

The EGR gas discharge passages 10-1, 10-2, 10
-3 are formed in the cylinder head 2 so as to lie at an acute angle with each of the suction ports 20-1, 20-2, and 20-3, so that the EGR gas flows through these suction ports. It will flow in the direction of the air flow,
EGR gas can be smoothly discharged to these suction ports.

The EGR gas passes through the common EGR gas communication port 15 of the gasket 6 and then flows through the three EGR gas branch passages 19-1, 19-2, and 19-3 of the spacer 5. Since the three EGR gas branch passages 19-1, 19-2, and 19-3 have the same cross-sectional area and the same length, E
GR gas can be equally distributed to each cylinder.

Further, the EGR gas common communication port 15 of the gasket 6 is also connected to the three EGR gas branch passages 19-of the spacer 5.
1, 19-2 and 19-3 are also formed in a pot-like shape when viewed from the front, and are formed along with each other. The inflow into the EGR gas branch passages 19-1, 19-2, and 19-3 is smoothly guided by the EGR gas common communication port 15.

Although the exhaust gas recirculation system in the present embodiment is applied to an in-line three-cylinder internal combustion engine, the invention is not limited to this, and an in-line multi-cylinder internal combustion engine or an in- It can also be suitably used for institutions and the like.

[Brief description of the drawings]

FIG. 1 is a partial elevational view of an internal combustion engine to which an exhaust gas recirculation device according to an embodiment of the invention described in claim 1 of the present application is applied.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a schematic plan view of the internal combustion engine of FIG. 1 with a cylinder head cover removed.

FIG. 4 is a side view of a connection surface of a cylinder head of the internal combustion engine of FIG. 1 with an intake manifold side as viewed from the front;

FIG. 5 is a front view of the gasket as viewed from a direction A in FIG. 3;

FIG. 6 is a front view of the spacer viewed from a direction A in FIG. 3;

FIG. 7 is a rear view of the spacer of FIG. 6;

FIG. 8 is an enlarged sectional view taken along line VIII-VIII in FIGS. 6 and 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Cylinder head, 2a ... Connection surface, 3
... intake manifold, 3-1, 3-2, 3-3 ... intake passage, 4 ...
Common flange, 5 ... Spacer, 6 ... Gasket, 7 ...
Surge tank, 8: Throttle body mounting flange, 8a: Mounting surface, 9: EGR gas intake passage, 9a ...
Upstream passage part, 9b ... Downstream passage part, 10-1, 10-2,
10-3: EGR gas discharge passage, 11: EGR valve, 12-1, 12-
2, 12-3… Exhaust port, 13… Gathering room, 14-1, 14-2, 14-3
... 1st mixture passage, 15 ... EGR gas common passage, 16-
1, 16-2, 16-3: EGR gas branch communication port, 17: Bead, 1
8-1, 18-2, 18-3: second mixture passage, 19-1, 19-2, 19-
3 ... EGR gas branch passage, 20-1, 20-2, 20-3 ... Suction port.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takuya Aoki 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Inventor Seishi Tsuneishi 1-4-1 Chuo, Wako-shi, Saitama No. Within Honda R & D Co., Ltd. (72) Inventor Shinzo Goto 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside of Honda R & D Co., Ltd. (72) Toru Amamiya 1-4-chuo, Wako-shi, Saitama No. 1 F-term in Honda R & D Co., Ltd. (reference) 3G062 AA03 EB15 EC16 ED02 ED11 ED13

Claims (1)

[Claims] 1. An exhaust gas recirculation device for an internal combustion engine that recirculates a part of exhaust gas to an intake system, wherein a resin intake manifold is connected to a cylinder head via a metal spacer and a metal gasket. A series of EGR gas suction passages and a number of EGR gas discharge passages corresponding to the number of cylinders are formed in the cylinder head. One end of the EGR gas suction passage is opened to an exhaust port, and the other end is opened. Is opened to a collecting chamber formed on a connection surface of the cylinder head with the intake manifold, and the middle thereof passes through an EGR valve attached to the cylinder head. EGR gas common communication port,
A number of EGR gas branch communication ports corresponding to the number of cylinders are formed, and the spacer has a joint surface with the gasket,
The number of EGs of equal length, which is in communication with the EGR gas common communication port and the EGR gas branch communication port and is equal in number to the number of cylinders.
An R gas branch passage is formed in a groove shape, and EGR gas sucked from the exhaust port is supplied to the EG.
The gas enters the EGR gas discharge passage through the R gas suction passage, the collecting chamber, the EGR gas common communication opening, the EGR gas branch passage, and the EGR gas branch communication opening, and flows in the EGR gas discharge passage through the EGR gas discharge passage. An exhaust gas recirculation device for an internal combustion engine, wherein the exhaust gas recirculates toward a suction port through a discharge port.