KR20020041083A - Intake air control device for diesel engine - Google Patents

Abstract

PURPOSE: An intake control apparatus for a diesel engine is provided to regulate air supply to the engine accurately and optimally according to engine RPM(Revolution Per Minute) by opening and closing a bypass line with supplying air from an air tank to an actuator selectively, and to reduce discharge of exhaust gas by burning optimally. CONSTITUTION: An intake control device of a diesel engine is composed of a turbocharger; a bypass line(9) discharging exhaust gas with bypassing a turbine(4); an actuator(10) opening and closing the bypass line; an air tank(20) storing air; a pressure regulator(21) adjusting pressure of air from the air tank with opening and closing pressure of the actuator; a solenoid valve(22) supplying pneumatic pressure from the pressure regulator to the actuator selectively according to a control signal; an intake pressure sensor(23) detecting suction pressure to the engine; an RPM sensor(24) detecting RPM of the engine; and an ECU(Electronic Control Unit)(25) regulating the air supply amount to the engine optimally by opening and closing the solenoid valve according to intake pressure and engine RPM.

Description

Intake air control device for diesel engine

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake control device for a diesel engine. In particular, according to the engine speed and the intake pressure supplied to the engine, the air pressure discharged from the air tank is selectively supplied to the actuator so that the exhaust gas bypasses the turbine of the turbocharger. By opening and closing the bypass line, the amount of air supplied to the engine can be precisely and optimally adjusted according to the engine speed, and the combustion can be optimized to significantly reduce the amount of exhaust gas. An intake control device for a diesel engine.

Figure 2 shows a conventional intake control device for a diesel engine,

Intake pipes 1 for intake of air necessary for the combustion operation of the engine 3 and exhaust pipes 2 for exhausting the exhaust gas generated during the combustion operation of the engine 3 are respectively formed on one side of the engine 3. On the intake pipe (1), a compressor (5) connected to the turbine (4) by the same central axis (6) is formed, and at the rear end of the compressor (5), the air compressed by the compressor (5) is cooled. And an intercooler 8 for supplying to the engine 3 is formed.

On the exhaust pipe 2, a turbine 4 forming a turbocharger is formed together with the compressor 5, and on the exhaust pipe 2, a separate bypass line for guiding exhaust gas to bypass the turbine 4 9) is formed, and on this bypass line 9, an actuator 10 for opening and closing the bypass line 9 is provided.

In addition, the compressor 5 and the actuator 10 are connected to the actuator 10 through a connection pipe 7 by connecting a part of the compressed air supplied to the engine when the compressor 5 is driven. The actuator 10 is configured to open when the supplied air is supplied to the actuator 10 with a predetermined pressure or more.

The conventional intake control device for a diesel engine configured as described above,

When the engine 3 is driven and exhaust gas is discharged through the exhaust pipe 2, the turbine 4 is rotated by the exhaust gas, and the rotational force of the turbine 4 is transmitted through the central shaft 6 to the compressor ( 5), the compressor 5 also rotates at high speed.

As the compressor 5 rotates, the air sucked through the intake pipe 1 is compressed and supplied to the intercooler 8, and the intake air is cooled while being passed through the intercooler 8 and supplied to the engine 3. The combustion operation of the engine is performed.

On the other hand, a part of the air compressed by the compressor (5) is supplied to the actuator (10) through a connecting pipe (7), the engine (3) in accordance with the air pressure supplied to the actuator (10) through the connecting pipe (7) The amount of air supplied to the air is controlled.

That is, when the engine is driven at a low speed, since the air pressure supplied from the compressor 5 to the actuator 10 is small, the actuator 10 is maintained in a state in which the bypass line 9 is blocked, and thus, the exhaust pipe 2 is used. As the exhaust gas discharged passes through the turbine 4 as it is, the amount of air supplied to the engine is appropriately adjusted by rotating the turbine 4.

When the engine rotates at a high speed, the rotation speed of the turbine 4 is increased, and the rotation speed of the compressor 5 interlocked with the engine 4 is also increased, so that the amount of air supplied to the engine by the compressor 5 is increased. When the air pressure is compressed and supplied to the actuator 10 through the connecting pipe 7 also increases, when the air pressure exceeds a predetermined value, the actuator 10 is operated to open the bypass line 9, thereby exhausting the exhaust pipe. A portion of the exhaust gas passing through (2) is bypassed through the bypass line 9 and discharged without passing through the turbine 4.

Therefore, when the engine rotates at a high speed, even though a large amount of air is required in the engine, the exhaust gas is bypassed along the bypass line 9 as the actuator 10 is opened by the high pressure air. As the rotational speed of the turbine 4 is relatively weakened, and the rotational speed of the compressor 5 is also weakened, the amount of air supplied to the engine is insufficient, resulting in a decrease in combustion power of the engine and incomplete combustion due to a decrease in combustion performance. As a result, the amount of smoke is increased, as well as the amount of NOx is generated, which causes a problem that the output of the engine is reduced during high-speed driving.

That is, in the conventional intake control device for diesel engines, since the operation of the actuator for opening and closing the bypass line depends entirely on the air pressure supplied from the compressor, the engine is driven at a high speed so that the air pressure supplied from the compressor to the actuator is kept above a predetermined value. If the actuator continues to be open, exhaust gas bypasses the turbine and bypasses the bypass line. As a result, the amount of air supplied to the engine decreases while the rotational force of the compressor decreases. Incomplete combustion due to the decrease in combustion performance increases the amount of smoke generated, the amount of NOx generated, and the output of the engine decreases at high speeds.

Accordingly, the present invention for solving the above problems is to bypass the exhaust gas to bypass the turbine of the turbocharger by selectively supplying the air pressure discharged from the air tank to the actuator in accordance with the engine speed and the intake pressure supplied to the engine By opening and closing the line, the diesel engine is able to precisely adjust the amount of air supplied to the engine according to the engine speed, and to significantly reduce the emission of exhaust gas by optimizing combustion. An object of the present invention is to provide an intake control device.

The present invention for achieving the above object,

A compressor and a turbine are mounted on the intake pipe and the exhaust pipe, and the turbocharger supercharges the intake air as the compressor rotates when the turbine is rotated by the exhaust gas, and the exhaust gas is discharged by bypassing the turbine on the exhaust pipe. In the configuration comprising a bypass line and an actuator for opening and closing the bypass line in accordance with the input air pressure,

An air tank for storing constant pressure air;

A pressure regulator for adjusting the air pressure discharged from the air tank to the opening / closing pressure of the actuator;

A solenoid valve which opens and closes according to an input control signal and selectively supplies air pressure discharged from the pressure regulator to the actuator;

An intake pressure sensor installed in the intake pipe to sense the intake pressure supplied to the engine;

A rotation speed sensor for sensing the rotation speed of the engine;

An ECU that opens or closes the solenoid valve in accordance with the intake pressure sensed by the sensor and the engine speed to adjust the amount of air supplied to the engine to an optimal state; Characterized in that consisting of.

1 is a view showing an intake control device for a diesel engine of the present invention.

2 is a view showing a conventional intake control device.

※ Explanation of code for main part of drawing

1: intake pipe 2: exhaust pipe

4 turbine 5 compressor

9: bypass line 10: actuator

20: air tank 21: pressure regulator

22: solenoid valve 23: intake air pressure sensor

24: Speed sensor 25: ECU

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

An intake pipe 1 and an exhaust pipe 2 are formed at one side of the engine 3, and the turbine 4, the compressor 5, and the intercooler 8 are provided at the intake pipe 1 and the exhaust pipe 2. On the exhaust pipe 2, a bypass line 9 is formed on the exhaust pipe 2 to guide the exhaust gas to bypass and discharge the turbine 4, and the air pressure supplied on the bypass line 9 is provided. Actuator 10 is opened and closed by, and such a configuration is the same as in the prior art.

Reference numeral 20 denotes an air tank 20 storing air of a constant pressure for driving the actuator 10, and by adjusting the air pressure output from the air tank 20 at the output end of the air tank 20 The pressure regulator 21 which adjusts to the extent which can open and close the actuator 10 is provided.

Reference numeral 22 is a solenoid valve installed at an output end of the pressure regulator 21 to drive on / off to selectively supply air pressure passing through the pressure regulator 21 to the actuator 10, and the solenoid valve 22 Is on / off driven by the control of the ECU 25 to be followed.

Reference numeral 23 denotes an intake pressure sensor installed at an input end of the engine 3 of the intake pipe 1 to detect the air pressure of the intake air supplied to the engine 3 and supply it to the ECU 25, and reference numeral 24 denotes an engine ( And a rotation speed sensor installed at 3) to sense the driving rotation speed of the engine 3 and supply it to the ECU 25.

ECU 25 is to control the solenoid valve 22 on / off according to the intake air pressure and the engine speed detected by the intake pressure sensor 23 and the rotational speed sensor 24,

The ECU 25 determines that the intake air amount is high and low in proportion to the engine speed when the engine is driven, and selectively drives the solenoid valve 22 on / off to drive the actuator 10 according to the determination result. It is to let.

That is, when it is determined that the amount of air supplied to the engine is small despite the high engine speed when the engine is driven, the ECU 25 turns off the solenoid valve 22 so that the actuator 10 opens the bypass line 9. As the exhaust gas discharged from the engine rotates the turbine 4, the amount of air supplied to the engine increases as the rotational speed of the compressor 5 increases.

In addition, if it is determined that the amount of air supplied to the engine is large despite the low engine speed during engine operation, the ECU 25 turns on the solenoid valve 22 so that the actuator 10 opens the bypass line 9. As a part of the exhaust gas discharged from the engine is bypassed and discharged through the bypass line 9, the amount of air supplied to the engine is gradually reduced while the rotational speed of the compressor 5 decreases.

In the present invention, even when the engine rotates at a low speed and does not require a large amount of air, the solenoid valve 22 is turned on so that the bypass line 9 is opened, thereby reducing the rotational speed of the compressor 5 to the engine. It is possible to reduce the amount of air supplied.

According to the present invention operating as described above by driving the solenoid 22 on / off in accordance with the engine speed and the amount of intake air supplied to the engine to precisely control the actuator 10 to adjust the amount of air supplied to the engine By precisely optimizing and controlling, the engine's combustion rate can be optimized, thereby reducing smoke and emissions.

In addition, as the amount of air supplied to the engine can be freely controlled, various grades of engines can be designed without any hardware change when developing the engine.

As described above, the present invention allows the air pressure discharged from the air tank to be selectively supplied to the actuator according to the engine speed and the intake pressure supplied to the engine, thereby opening and closing the bypass line for the exhaust gas to bypass the turbine of the turbocharger. Thus, the intake control for diesel engines can precisely adjust the amount of air supplied to the engine according to the engine revolutions, and achieve a significant reduction in the amount of exhaust gas as the combustion can be optimized. The effect of providing the device can be expected.

Claims (1)

The compressor 5 and the turbine 4 are mounted on the intake pipe 1 and the exhaust pipe 2, and the turbocharger supercharges the intake air while the compressor 5 rotates when the turbine 4 rotates due to the exhaust gas. And a bypass line (9) formed on the exhaust pipe (2) to exhaust exhaust gas by bypassing the turbine (4), and an actuator (10) for opening and closing the bypass line (9) in accordance with the input air pressure. In what comprises, An air tank 20 for storing constant pressure air; A pressure regulator 21 for adjusting the air pressure discharged from the air tank 20 to the opening and closing pressure of the actuator 10; A solenoid valve 22 which opens and closes according to an input control signal and selectively supplies the air pressure discharged from the pressure regulator 21 to the actuator 10; An intake pressure sensor 23 installed in the intake pipe 1 to sense the intake pressure supplied to the engine 3; A rotation speed sensor 24 sensing a rotation speed of the engine 3; An ECU 25 for opening and closing the solenoid valve 22 according to the intake pressure and the engine speed detected by the sensors 23 and 24 to adjust the amount of air supplied to the engine 3 to an optimal state; Intake control device for a diesel engine, characterized in that consisting of.