KR900009310Y1 - Starting engine control device of fuel injection pump for diesel engine - Google Patents

Abstract

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Description

Starting angle regulator of diesel fuel injection pump

1 is a cross-sectional view showing the configuration of a distribution type fuel injection pump.

2 is a conventional state of the art device for installing.

3 is a cross-sectional view of the adjustment device of the present invention.

Figure 4 is a comparison chart between the conventional configuration and the present invention.

5 is a configuration diagram of the combination of the piston and the solenoid valve.

* Explanation of symbols for main parts of the drawings

10: solenoid valve 4: timer piston

The present invention relates to a start-up timing control device of a hydraulic timer installed inside a dispensing fuel injection pump of a diesel engine to variably adjust the fuel injection timing according to the rotational speed of the engine.

Looking at the general function of the timer, the pressure generated in the plunger chamber by the driving of the fuel injection pump is a pressure wave is transmitted to the injection pipe at high speed to reach the nozzle.

The fuel injected from the nozzle is ignited and burned after passing the ignition delay time.

The time that the pressure wave propagates in the injection tube does not change much depending on the rotational speed of the engine, but the higher the crank turn angle of the ignition delay time is, the higher the speed is.

That is, the high speed side becomes shorter in the ignition delay time, but becomes larger in view of the frank angle, so that the crank angle that rotates from the pressure generation time of the plunger chamber to the ignition becomes larger as the speed becomes higher.

For this reason, it is necessary to accelerate the injection time at high speed, that is, the time when pressure is generated in the injection pump, with respect to the crank angle of the engine so that the ignition time is constant and the most appropriate combustion state is achieved for any rotation angle.

It is the function of the timer to change the phase between this period and the driving shaft of the injection pump to speed up the injection timing when the rotational speed increases, and to delay the injection timing when the speed drops.

Looking at the forward operation of the distributor fuel injection pump (FIG. 1), as shown in FIG. 1, the fuel injection pump is supplied through a supply pump 1 composed of four vanes 2 in which the fuel of the fuel tank is driven by the fuel injection pump. Pulls fuel into me.

The fuel pressure inside the housing generally has a correlation with the number of revolutions (P = CV ^2, where P is the pressure, V is the speed, and C is the constant).

In addition, in the dispenser type injection pump, the advance characteristic of the timer A is determined by the hydraulic pressure, ie, the fuel pressure applied to the timer piston 4.

A conventional timer configuration is shown in FIG. 2 and includes a cam piston 5 connected to a timer piston 4 operated by fuel oil pressure generated inside the housing, a spring 3 assisting the return stroke, and a timer piston. It consists of a timer pin (6) that is a connecting rod to rotate.

Therefore, when the engine speed increases, the fuel oil pressure in the injection pump housing 7 rises, and the timer piston 4 is pushed in the direction opposite to the engine rotation direction. On the contrary, when the hydraulic pressure drops, the timer piston 4 Is returned.

According to the movement of the timer piston, the timer pin 6 moves the roller holder 8 in the circumferential direction. When the rotational speed of the engine is increased and the pressure from the feed pump is increased, the roller holder 8 is cam. The injection timing is advanced by turning in the opposite direction of rotation of the disk.

However, in the use of such a conventional timer device, if the initial advance is increased for the purpose of improving startability including a cold light, the advance amount is increased by a certain amount in the entire rotational speed section, so that durability is weakened and pollution is generated. There is a problem that it becomes difficult to satisfy the pollution regulations.

The present invention has been devised to compensate for such problems in the conventional timer device, and to devise an advancing control device to improve the startability including cold start of the engine while maintaining the basic performance of the timer bar, its purpose When described in detail by the accompanying drawings to solve the configuration as follows.

The upper part of the timer pin 6 is connected to the roller holder 8 which is installed in the pump housing 7 and can adjust the injection timing, and the lower end thereof is connected to the timer piston 4 in the cylinder, and one side of the timer piston 4 The solenoid valve 10 at the rear end of the cylinder in such a way that the roller holder 8 and the cam disk 5 can advance the injection timing by the pressure from the supply pump 1 so as to hold the timer spring 3. It is characterized in that to allow the timer piston (4) to rise by a predetermined interval to install.

In this way, the present proposal then operates the solenoid valve 10 using a switch as necessary, whereby the solenoid valve 10 is powered from a battery of an automobile.

Accordingly, when the switch is turned on at the initial start of the engine, the solenoid valve 10 acts as shown in FIG. 5 to push the timer piston 4 by a predetermined starting advance amount Q, thereby increasing the amount of advance. On the other hand, when the switch is off, it is returned to its original position by the spring.

In this way, the advance control device can increase the start-up angle only when necessary, such as cold start, while maintaining the basic performance of the timer. It is a useful design that can be easily solved without the need for a separate device for exhaust emission regulations that are gradually strengthened while improving engine durability.

Claims (1)

A start-up timing control device of a diesel fuel distribution pump of diesel engines in which a solenoid valve 10 is installed at the rear end of a normal start-up progress regulator to push the timer piston 4 to increase the start-up progression amount when the engine is initially started. .