KR20030046697A - A gasoline direct injection engines - Google Patents

Abstract

PURPOSE: A gasoline direct injection type engine is provided to improve combustion performance of an engine by diagonally arranging intake and exhaust ports with installing a directional valve at one side of an intake manifold. CONSTITUTION: An intake valve is formed by diagonally arranging intake ports(3,5) corresponding to each combustion chamber(1). An injector is positioned below the intake valve. A bowl section(15) is formed on an upper surface of a piston(11) in such a manner that intake air flowing into the combustion chamber through the intake ports has a tumble flow. A stratifying mixer is formed around an ignition plug positioned at a center of the combustion chamber, so an amount of air introduced into the combustion chamber is maximally maintained in a high-speed and high-load area and a combustion speed is rapidly maintained in a low-speed and low-load area.

Description

Gasoline Direct Injection Engines {A GASOLINE DIRECT INJECTION ENGINES}

The present invention relates to a gasoline direct injection engine, and more particularly, by configuring a diagonal arrangement of the intake and exhaust ports and two switching valves on one side of the injector and the intake manifold, thereby increasing volumetric efficiency when controlling the flow of intake air. The present invention relates to a gasoline direct injection engine that can further improve combustion performance.

In general, gasoline direct injection (GDI) engines in which only air is sucked into the combustion chamber and fuel is injected directly into the combustion chamber by an electronically precisely controlled injector. Of course, it is possible to form a stratified mixer to achieve high power and low fuel consumption simultaneously.

In other words, the gasoline direct injection engine has three areas: theoretical air fuel ratio, lean driving zone and ultra-lean driving zone. Ideally, only the ultra-lean driving zone is pursued, but when the actual vehicle speed is below a certain level and the water temperature is below a certain range, For stability, the theoretical air-fuel ratio operation should be maintained and a lean driving region between the theoretical air-fuel ratio region and the ultra-thin operating region should be made to minimize the impact of frequent round trips between the two regions.

Meanwhile, the Electronic Management System (hereinafter referred to as 'EMS') for Multi Point Injection (hereinafter referred to as 'MPI') selectively selects SCV (Swirl Control Valve: referred to as 'SCV'). However, the gasoline direct injection engine (GDI) electronic control system (EMS) must use the SCV to control the degree of intake flow.

In other words, SCV in MPI engine is optionally used in lean-burn engine as needed, and its operating level is only open / closed in two stages, but SCV in GDI engine must be used to make proper intake flow in ultra-lean operation. In addition, the control of the SCV should be controlled finely by dividing the opening and closing into a plurality of stages. For this reason, it is necessary to create a proper flow in ultra-thin operation because it has a value that depends on the load and speed of the engine.

This is a stratified combustion in which the fuel is injected at the end of the compression stroke (just before the ignition period) in the partial load operation region to increase the air-fuel ratio around the spark plug, so that the ignition can be easily performed even at the ultra-thin air-fuel ratio (25-40: 1). In the full load operation region, the fuel is injected at the beginning of the intake stroke to improve the filling efficiency by cooling the intake air by the theoretical air-fuel ratio (14.7: 1) fuel, thereby forming a uniform mixer to achieve high output.

However, there is a problem of lowering the low and medium speed torque, deteriorating fuel economy, and increasing harmful exhaust gas. In the case of the conventional gasoline direct injection engine, as described above, in the intake manifold or the intake port, swirl is performed to control the intake flow. The control valve is installed to induce strong swirl flow into the combustion chamber, and is commonly used in lean burn engines or ultra-thin direct injection engines to perform lean operation by improving combustion stability by enhancing the flow.

However, in the above-described lean burn engine or ultra-lean direct injection engine, the swirl control valve acts as a resistance in terms of its deployment performance, thereby limiting the amount of air sucked into the combustion chamber of the engine, thereby reducing the volumetric efficiency. This will cause a decrease in output. In addition, since one of the two intake ports has a structure for controlling flow by using an intake manifold or a swirl control valve installed at the intake port, the flow and combustion forms in the combustion chamber are asymmetrical to ensure combustion stability. This implies a problem of falling and causing deterioration of fuel efficiency and exhaust gas.

Therefore, the present invention, as described above, to solve the above problems by improving the development performance of the gasoline direct injection engine to ensure the stability of the combustion, the object of the present invention is the diagonal arrangement of the intake, exhaust port and two By providing a switching valve on one side of the two injectors and the intake manifold, it is to provide a gasoline direct injection engine that can increase the volumetric efficiency and improve the combustion performance when controlling the flow of intake air.

1 is a principle diagram of a gasoline direct injection engine according to the present invention.

2 is a cross-sectional configuration diagram of a gasoline direct injection engine according to the present invention.

3 is a manifold configuration diagram of a gasoline direct injection engine according to the present invention.

4 is a layout view of the intake and exhaust valves of the gasoline direct injection engine according to the present invention.

5 is an overall configuration diagram of an intake manifold according to the present invention.

FIG. 6 is a first operation state diagram of the gasoline direct injection engine according to FIG. 3.

FIG. 7 is a second operation state diagram of the gasoline direct injection engine according to FIG. 3.

The present invention for achieving the above object, in the gasoline direct injection engine,

Two intake ports and two exhaust ports are disposed in diagonal directions to each other on the cylinder head in correspondence with the pistons in each combustion chamber of the cylinder block, and an injector is mounted below the two intake ports arranged in the diagonal directions, respectively. Characterized in that the switching valve is configured on one side on the intake manifold divided into two so as to be connected to the two intake ports,

Wherein the piston is formed on the upper surface to form a pole portion consisting of a taegeuk pattern groove so that the air sucked through the intake port corresponding to the two injector flows to form an inclined tumble flow shape,

Each catalyst is formed on an exhaust manifold connected to the two exhaust ports, corresponding to the respective exhaust ports.

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

1 is a principle diagram of a gasoline direct injection engine according to the present invention.

2 is a cross-sectional configuration diagram of a gasoline direct injection engine according to the present invention.

3 is a manifold configuration diagram of a gasoline direct injection engine according to the present invention.

4 is a layout view of the intake and exhaust valves of the gasoline direct injection engine according to the present invention.

5 is an overall configuration diagram of an intake manifold according to the present invention.

First, referring to the principle of the present invention through FIG. 1, the intake ports 3 and 5 on the cylinder head are arranged diagonally to correspond to each combustion chamber 1 of the cylinder block to form an intake valve, and the lower portion thereof. Injectors are formed one by one, and on the upper end surface of the piston 11, the flow of intake air supplied to the combustion chamber 1 through the intake ports 3 and 5 is centered so as to be in the form of an inclined tumble flow 13. By configuring the vowel portion 15 constituted by the taiji pattern groove, the ignition plug (not shown) in which the intake air supply direction is located at the center of the combustion chamber in a diagonal direction from each other through the two intake ports 3 and 5 In order to form a stratified mixer around, it is possible to maximize the volumetric efficiency by maintaining the maximum amount of air sucked into the combustion chamber in the high speed and high load region, and inclined in the low speed and low load region. Block flow can be faster burning rate by the effect of the 13 is to obtain the knocking suppressing effect.

Looking at the configuration of the gasoline direct injection engine according to the present invention using this principle, as shown in Figs. 2 to 5, as shown in Figs. 2 and 4, the piston in each combustion chamber 1 of the cylinder block 21 Corresponding to (11), two intake ports (3, 5) and two exhaust ports (7, 9) are arranged on the cylinder head (23) in a diagonal direction to each other, respectively, to intake valve (25) and exhaust valve (27). )).

On the cylinder head 23, injectors 29 and 31 for injecting fuel are mounted to each lower portion of each of the two intake ports 3 and 5 arranged in a diagonal direction.

Here, the piston 11 may form an inclined tumble flow 13 by flowing air sucked through the intake ports 3 and 5 corresponding to the two injectors 29 and 31 on the upper surface thereof. It is made by forming a Paul 15 consisting of grooves in the shape of a taegeuk pattern symmetrically with respect to the center.

In addition, the intake manifold 33 connected to the two intake ports 3 and 5 arranged in the diagonal direction is divided into both sides immediately after the throttle valve 35 as shown in FIG. 37 is connected to one side between the throttle valve 35 and the surge tank 37 on the intake manifold 33 divided into both sides, the switching valve 39 is mounted.

On the exhaust manifold 41 connected to the two exhaust ports 7 and 9, respectively, as shown in FIG. 3, the catalysts 43 and 45 corresponding to the respective exhaust ports 7 and 9, respectively. Configure separately.

Therefore, according to the gasoline direct injection engine according to the present invention having the configuration as described above, in the high speed high load operating region, as shown in FIG. Is mounted on the fold so that intake and exhaust flow through both intake pipes 3a and 5a and exhaust pipes 7a and 9a, and the combustion chamber ( In order to maintain the maximum amount of air sucked into 1), the combustion performance can be improved while maximizing the volumetric efficiency of the intake pipes 3a and 5a, thereby maximizing the torque and output of the engine. .

On the other hand, in the low speed low load operation region, as shown in Fig. 7, the switching valve 39 (expression, mounted on the divided intake manifold between the surge tank and the throttle valve) is closed, so that the intake and exhaust are intake pipes. (5a) and both exhaust pipes (7a, 9a) flows, and in the intake process to enhance the flow, in the exhaust process to reduce the hydrocarbon activation during cold start by shortening the catalyst activation time by the intake and exhaust reversal effect do.

In addition, the combustion stability of the engine according to the improvement of the intake air flow is improved in the partial load and idle operation region, thereby improving the fuel efficiency and reducing the exhaust gas.

According to the gasoline direct injection engine of the present invention made as described above, two intake ports and two exhaust ports arranged on the cylinder head are arranged in diagonal directions with each other, and an injector is installed below the two intake ports, respectively. One side of the intake manifold is provided with a switching valve, and when controlling the flow of intake air, by removing the conventional swirl control valve, the volumetric efficiency of the intake pipe is increased, and the inlet air is supplied to be inclined tumble in a diagonal direction in the inlet air. The combustion performance can be further improved, and the switching valve is opened and closed according to operating conditions such as high speed high load and low speed low load to secure combustion stability by controlling intake air amount and intake flow enhancement, and improving fuel efficiency. It shows the effect of reducing exhaust gas.

Claims (3)

In a gasoline direct injection engine, Two intake ports and two exhaust ports are disposed in diagonal directions to each other on the cylinder head in correspondence with the pistons in each combustion chamber of the cylinder block, and an injector is mounted below the two intake ports arranged in the diagonal directions, respectively. Gasoline direct injection engine, characterized in that the switch valve is configured on one side on the intake manifold divided into two so as to be connected to the two intake ports. The method of claim 1, wherein the piston The gasoline direct injection engine is formed on the top surface of the injector port corresponding to the two injector air inlet flows through the inlet tumbled to form a twirl pattern groove to form a tumble flow form . The gasoline direct injection engine according to claim 1, wherein each catalyst is formed on an exhaust manifold connected to each of the two exhaust ports corresponding to the respective exhaust ports.