KR20030089247A - Apparatus for cutting off supply of air in air system when a diesel engine is stopped - Google Patents

Abstract

PURPOSE: An apparatus is provided to reduce noises and vibrations of diesel engine by completely cutting off the air being supplied into the cylinder simultaneously with the stoppage of engine. CONSTITUTION: An apparatus comprises a throttle flap(10) arranged in an intake manifold(3), and which cuts off the supply of air by rotating centering from a center shaft(10a); and a rotating unit connected to the throttle flap, and which rotates the throttle flap. The rotating unit includes a link(15) connected to the center shaft of the throttle flap and which rotates the throttle flap; a rod(20) connected to the link and which permits the link to reciprocate; an actuator(30) connected to the rod and which permits the rod to reciprocate by the displacement of the pressure; a vacuum tank(40) for storing vacuum for displacement of the pressure of the actuator; a valve(50) interposed between the vacuum tank and the actuator and which opens/shuts the vacuum tank; and a control unit(60) for opening the valve simultaneously with the engine turn-off.

Description

Apparatus for cutting off supply of air in air system when a diesel engine is stopped}

The present invention relates to an air system of a diesel engine, and more particularly, to an air shutoff device which is installed in an intake manifold to quickly cut off air supplied to a combustion chamber at start-off.

In general, a diesel engine inhales only air into a cylinder, and fuel is injected through an injection nozzle and an injector into air compressed at high temperature and high pressure at the end of the compression stroke. At this time, when the air temperature is higher than the self ignition temperature of the fuel, the injected fuel is atomized and evaporated in the compressed hot air, so that an optimum mixing ratio capable of self ignition is formed in the combustion chamber and combustion starts. This is called compression autoignition, and the fuel injected thereafter continues by forming a spray jet and mixing it with the surrounding air. Therefore, it is important to mix fuel and air well as the basis of combustion of diesel engine.

Modern diesel engines use a direct injection method that sends only air from the intake manifold and injects fuel directly into the cylinder during the intake stroke. The reason for this is that the direct injection method enables low fuel consumption and reduced emissions, and also enables the engine to be more comfortable and quiet than the general preburn engine. This direct injection method is used because it is superior to the general diesel engine.

There is a need for an air system to enable direct injection of such diesel engines. As shown in FIG. 1, in the air system, after the air is sucked through the air cleaner 1, the air amount is measured by the air flow sensor 2. Thereafter, the purified air flows through the intake manifold 3 which is connected to communicate with the air cleaner 1. This air passes through the intake manifold 3 and is supplied to each cylinder 4. Thereafter, the fuel is injected through the injection nozzle and the injector (not shown) to the compressed air at high temperature and high pressure by receiving a signal from the controller 5, and combustion is started through self compression ignition.

However, the conventional air system as described above uses an airflow sensor to measure the intake air amount, but is different from the air amount measured by the airflow sensor mounted near the air cleaner and the air amount actually entering the cylinder. Accordingly, there is a problem in that noise and vibration are excessively generated in the diesel engine because air that has already passed through the airflow sensor is supplied to the cylinder and combusted with the remaining fuel when the engine is turned off.

The present invention has been made in view of the above, and the air shutoff of the air system of the diesel engine during start-off, which significantly reduces the noise and vibration of the diesel engine by temporarily blocking the air sucked into the cylinder at the same time as the start-off The purpose is to provide a device.

1 is a schematic diagram showing the configuration of an air system of a general diesel engine.

Figure 2 is a schematic diagram showing the configuration of an air system equipped with a device according to the present invention.

Figure 3 is an enlarged view showing a state before operation of the air shutoff device according to the present invention.

Figure 4 is an enlarged view showing a state after the operation of the air shutoff device according to the present invention.

Explanation of symbols on the main parts of the drawings

3: intake manifold 10: throttle flap

10a: central axis 20: rod

30: actuator 31: spring

32: membrane 33: housing

33a: through hole 40: vacuum tank

50: valve 60: control unit

In order to achieve the above object, the present invention is installed in the intake manifold, a throttle flap for blocking the air sucked while rotating about the central axis across the center; And rotation means connected to the throttle flap to rotate the throttle flap.

Preferably, the rotation means is connected to a central axis of the throttle flap to rotate the throttle flap, a rod connected to the link to reciprocate the link, and a load connected to the rod by displacement of the pressure applied therein. An actuator for reciprocating motion, a vacuum tank for storing a vacuum for displacing the pressure of the actuator, a valve installed between the vacuum tank and the actuator to open and close the vacuum tank, and a control unit for opening the valve at the same time as the start-off.

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

As shown in Figures 2, 3 and 4, the air blocker 100 according to the present invention is a throttle flap 10, link 15, rod 20, actuator 30, vacuum tank 40 ), The valve 50 and the control unit 60.

The throttle flap 10 is installed inside the intake manifold 3 to block air sucked while rotating about the central axis 10a crossing the center.

The link 15 is connected to the central axis 10a of the throttle flap 10 to rotate the throttle flap 10. The link 15 has a '-' shape, one end is fastened with a central shaft 10a and a bolt, the other end is fastened with a rod 20 and a bolt to be described later.

The rod 20 is connected to the link 15 to reciprocate this link 15.

The actuator 30 is composed of a spring 31 and a metal or non-metal membrane 32 installed on top of the spring to reciprocate the rod 20 rotatably connected to the membrane in accordance with the displacement of the internal pressure. Then, at a portion where the rod 20 of the housing 33 extends outwardly, a through hole 33a having a predetermined size is formed to match the rotation radius of the link 15, and the through hole 33a rotates the link 15. Accordingly, it is possible to move forward and backward in FIGS. 3 and 4. Although not shown, the actuator 30 is fixed to the side wall of the intake manifold 3 by a bracket.

The vacuum tank 40 stores a vacuum for displacing the pressure of the actuator 30. The vacuum tank 40 is installed to communicate with a brake master cylinder (not shown), and stores the vacuum generated when the brake pedal is pressed.

The valve 50 is installed between the vacuum tank 40 and the actuator 30, and opens and closes the vacuum tank 40.

The control unit 60 opens the valve 50 at the same time as the start-off.

With this configuration, the vacuum generated in the brake master cylinder when the brake pedal is pressed is stored in the vacuum tank 40. Simultaneously with the start-off, the controller 60 outputs a signal to open the valve 50 to open the valve 50. At this time, the lower side of the membrane 32 in which the spring 31 inside the actuator 30 is installed is in a vacuum state. Accordingly, the inside of the actuator 30 pulls the rod 20 by the displacement of the pressure applied from the top to the bottom, and the rod 20 reciprocates the link 15, and the operation of the link 15 is performed. By this, the central axis 10a of the throttle flap 10 is rotated. Therefore, the throttle flap 10 is rotated at the same time as the start-off, and the air passing through the intake manifold 3 is cut off quickly.

That is, the throttle flap 10 is used in the intake manifold 3 to significantly reduce the noise and vibration of the diesel engine due to the resonance generated during the start-off in the idle state of about 700 to 800 RPM. It is equipped with an air shutoff device to shorten the reaching time from idle to 0 RPM as much as possible, and significantly suppresses the generation of noise and vibration of other parts constituting the diesel engine such as a manual transmission.

As described above, the apparatus according to the present invention has the effect of significantly reducing the noise and vibration of the diesel engine by completely blocking the air sucked into the cylinder at the same time as the start-off.

In the above, the present invention has been illustrated and described with respect to certain preferred embodiments. However, the present invention is not limited only to the above-described embodiments, and those skilled in the art to which the present invention pertains may vary without departing from the spirit of the technical idea of the present invention described in the claims below. It will be possible to carry out the change.

Claims (2)

A throttle flap installed inside the intake manifold and blocking air sucked while rotating about a central axis crossing the center; And And a rotation means connected to the throttle flap to rotate the throttle flap. According to claim 1, wherein the rotating means is connected to the central axis of the throttle flap, the link for rotating the throttle flap, a rod connected to the link for reciprocating the link, and is connected to the rod applied to the inside An actuator for reciprocating the rod by a displacement of a losing pressure, a vacuum tank for storing a vacuum for displacing the pressure of the actuator, a valve installed between the vacuum tank and the actuator and opening and closing the vacuum tank; Air blocking device of the air system, characterized in that consisting of a control unit for opening the valve at the same time starting off.