KR20010057512A - An intake port structure of dohc engines - Google Patents

Abstract

PURPOSE: An intake port of a DOHC(Double Overhead Camshaft) engine is provided to realize complete combustion by stratifying the mixed exhaust gas and mixture reduced via an EGR(Exhaust Gas Recirculation) device. CONSTITUTION: Two intake ports(14A,14B) and two exhaust ports(16) are formed on a combustion chamber(12) of a DOHC engine, and a spark plug(18) is installed at the center of the combustion chamber. The intake ports are connected to a plenum chamber(22) having an air inlet(20) to receive suction air. Two injectors(24A,24B) are formed in the intake ports to inject fuel to the air supplied from the plenum chamber. Thus, the mixture of air and fuel is supplied to the combustion chamber via the intake ports. Herein, one of the intake ports is a tumble port(14A) and the other is a swirl port(14B). An EGR tube(26) is formed in the swirl port to flow reductive exhaust gas recirculated by the EGR device into the swirl port and is opened and shut off by a solenoid valve(28) operated by an ECU(Electronic Control Unit)(30). The injectors are also controlled by the ECU. According to the swirl port and the tumble port, the mixture is stratified into mixture flow of air and reductive exhaust gas and the other mixture flow of air and fuel. With the structure, an EGR ratio is increased up to 50%. Therefore, fuel efficiency is improved over 10% while exhaust gas is reduced.

Description

AN INTAKE PORT STRUCTURE OF DOHC ENGINES}

The present invention relates to an intake port structure of a DOHC engine, and more particularly, to prevent power loss during full load operation of the engine, and to reduce exhaust gas in the combustion chamber during partial load operation of the engine. And an intake port structure of a DIOH engine that reduces exhaust gas and improves fuel efficiency by allowing a mixture of fuel and air to form a stratified structure capable of complete combustion.

Recently, as consumers prefer vehicles with powerful output engines, the engines equipped with two so-called DIOH engines have been increased by increasing the intake and exhaust valves one by one in the cylinder head. It is spreading a lot.

A vehicle internal combustion engine including such a DOHC engine is generally powered by burning a mixer in which fuel and air are mixed to obtain power, and is introduced into a combustion chamber forming a constant closed space. Since a high performance engine output is obtained according to the combustion degree of the mixer, the combustion efficiency greatly depends on the flow shape of the combustion chamber of the mixer into which the mixer is introduced.

As a result, mixing the flow of the mixer flowing into the combustion chamber to some extent serves as an important factor for improving the combustion efficiency. As shown in FIG. 3, two intake ports 112 and two exhaust ports are shown. In the DIOH engine having 114, two intake ports 112 are formed as tumble ports 112A and 112B so as to give direction to the mixer, and air is supplied to these tumble ports 112A and 112B. Air is introduced into one side of the plenum chamber 116 for introducing the gas, and the other side allows the exhaust gas recycled from the exhaust manifold to be introduced by an exhaust gas recirculation device (EGR, EXHAUST GAS RECIRCULATION), and then the plenum chamber At 116, the homogeneous exhaust gas and air are mixed to allow the mixer to be injected into the combustion chamber 120 by the injector 118.

As such, the air, the fuel, and the reducing exhaust gas are uniformly mixed and introduced, so that the intake air flow in the combustion chamber is formed such that the mixture is evenly distributed throughout the combustion chamber 120 as shown in FIG. 4 to reduce emission. High performance of the engine performance can be obtained.

However, the application of the EGR to the mixer supplied to the combustion chamber as described above is to reduce the emission and improve fuel efficiency during the engine's part load operation, but with air and fuel in the plenum chamber When mixed, the EGR rate is usually only 5-10%.

This is because when the exhaust gas is homogeneously mixed with air and fuel in the plenum chamber, if too much exhaust gas is mixed with the air and fuel, the combustion state becomes unstable and incomplete combustion occurs in the combustion chamber, resulting in emission of fuel and fuel economy. Because it brings deterioration.

Accordingly, the conventional intake port structure of the DIOH engine does not use the exhaust gas reduced through the EGR device as efficiently as possible.

Accordingly, the present invention is to solve the above problems, an object of the present invention is to not affect the output in the full load operating region of the engine, the exhaust gas and fuel reduced through the EGR device in the partial load operating region of the engine It is to provide an intake port structure of the DIOH engine which can stratify the air mixture so that it can be completely burned.

1 is a structural diagram of an intake port of a DIOH engine according to the present invention;

2 is a cross-sectional view of a combustion chamber to which an intake port of a DIOH engine according to the present invention is applied during partial load operation of the engine;

3 is a structural diagram of an intake port of a DIOH engine according to the prior art;

4 is a sectional view of a combustion chamber of an intake port of a DIOH engine according to the prior art.

<Explanation of symbols for the main parts of the drawings>

12: combustion chamber 14A: tumble port

14B: Swirl port 18: Spark plug

20: air inlet 22: plenum chamber (Plenum chamber)

24A, 24B: Injector 26: EGR pipe

28: solenoid valve 30: electronic control unit (ECU)

S: air + reducing exhaust gas

T: air + fuel

In order to achieve the above object, the present invention,

Two intake ports, a plenum chamber for supplying outside air to the intake port, and a connection portion between the plenum chamber and the intake port for injecting fuel into the intake port so that air and fuel are mixed and supplied to the intake port In a DIOH engine comprising an injector, one of the two intake ports consists of a tumble port that directs the mixer into the combustion chamber, and the other intake port vortexs the mixer into the combustion chamber for injection. And a swirl pot, wherein one side of the swirl pot is selectively opened and closed by an electronic controller to form an EGR tube for introducing reducing exhaust gas from the EGR apparatus into the swirl pot. Provide an intake port structure.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention that can specifically realize the above object will be described.

Referring to FIG. 1, an intake port structure of a DIOH engine according to a preferred embodiment of the present invention is shown.

In the combustion chamber 12 of the DIOH engine, two intake ports 14A and 14B and two exhaust ports 16 are formed, and a spark plug 18 is provided at the center thereof.

The two intake ports 14A and 14B are connected to one plenum chamber 22 in which an air inlet 20 is formed at one side thereof to receive intake air, and two air inlet ports 14A and 14B are provided from two plenum chambers 22. Two injectors 24A and 24B are formed at the connection portion divided into the intake ports 14A and 14B to inject fuel into the air supplied from the plenum chamber 22 so that a mixture of air and fuel is supplied to the combustion chamber through the intake port. To (12).

In the DIOH engine, which is configured as described above, in two intake ports through which a mixture of air and fuel passes, one of the intake ports is a tumble port 14A capable of directing the mixer directly into the combustion chamber. The other intake port consists of a swirl port 14B which allows the mixer to vortex and be injected into the combustion chamber.

In addition, an EGR tube 26 is formed at one side of the swirl pot 14B so that the reducing exhaust gas recycled by the exhaust gas recirculation apparatus EGR may be introduced into the swirl pot.

The EGR pipe 26 is provided with a solenoid valve 28 for opening and closing the EGR pipe 26 to open and close the EGR pipe in accordance with the operating state of the engine by the electronic control unit 30.

On the other hand, the tumble port side injector 24A and the swirl port side injector 24B are also controlled by the electronic control unit 30, respectively.

Looking at the intake process into the combustion chamber by the intake port structure of the DIOH engine of the present invention made as described above are as follows.

First, it is important to obtain the maximum power in the full load operation state of the engine, so that only a mixture of air and fuel is introduced into the combustion chamber without applying the EGR. That is, the electronic control unit 30 closes the solenoid valve 28 so that the reducing exhaust gas does not flow into the swirl port 14B through the EGR pipe 26, and the tumble port side injector 24A. Each of the swirl pot side injectors 24B is operated so that only a mixture of air and fuel can be supplied into the combustion chamber.

Next, it is important to reduce fuel consumption and emission in the part load operation state of the engine, so that reducing exhaust gas and other mixers (air and fuel) form a stratified structure while applying EGR. . That is, the solenoid valve 28 is opened to operate so that the reducing exhaust gas flows into the swirl pot 14B through the EGR pipe 26, and only the tumble port side injector 24A is operated. Do not operate the side injector 24B. According to such a control operation, a mixture of air and fuel is supplied through the tumble port 14A, and a mixture of air and reducing exhaust gas is supplied through the swirl port 14B.

Here, as shown in FIG. 2, since the mixer S of the air and the reduced exhaust gas supplied through the swirl port 14B forms a vortex, the edge portion is rotated in the combustion chamber 12, and the tumble port ( The mixture T of air and fuel supplied through 14A) is spread in the center portion of the combustion chamber 12, and the structure of the mixer is a mixture of air S and a mixture of air and fuel S. It will be stratified into two layers.

At this time, since the mixer (S) of the air and the reducing exhaust gas is located in the crevice volume (C.V.) of the edge of the combustion chamber, it is possible to further reduce the hydrocarbon (HC).

According to the intake port structure of the DIOH engine of the present invention as described above, the EGR ratio that can be applied in the combustion chamber according to the stratification structure in the combustion chamber due to the combination application of the tumble port and the swirl pot during partial load operation of the engine is about. It can increase by 50%, thereby significantly reducing the emission of exhaust gas, and can improve fuel economy by about 10% or more.

In particular, since reducing exhaust gas may be applied to the crevice volume of the combustion chamber according to the stratified structure of the mixer in the combustion chamber, the effect of reducing the hydrocarbon (HC) is excellent.

Claims (1)

Two intake ports, a plenum chamber for supplying outside air to the intake port, and a connection portion between the plenum chamber and the intake port for injecting fuel into the intake port so that air and fuel are mixed and supplied to the intake port In the DOHC engine including an injector, At the two intake ports One of these intake ports consists of a tumble port which directs the mixer directly into the combustion chamber, The other intake port consists of a swirl port for swirling and injecting the mixer into the combustion chamber. An intake port structure of a DOHC engine, characterized in that an EGR tube is formed on one side of the swirl pot to be selectively opened and closed by an electronic controller to introduce reducing exhaust gas from the EGR device into the swirl pot.