JPS60128970A - Fuel injection device - Google Patents

Abstract

PURPOSE:To improve the control accuracy and performance of fuel injection pump by constructing a valve for regulating the pressure of fuel to be fed from pressure fuel feed mechanism with pressure regulating section and solenoid valve section while transmitting a command to be fed to solenoid valve section fluidly to pressure regulating section thus performing control. CONSTITUTION:Upon fuel supply through feed port 15 of pressure regulating valve 3 into oil chamber 18, piston 13 in pressure regulating section is moved to the right to flow fuel through restrictor 19 into oil chamber 17. Upon increase of pressure in oil chamber 18, a discharge port 16 will open to discharge fuel into fuel tank 1. Consequently, pressure in oil chamber 18 will drop to move the piston 13 to the left thus to close the discharge port 16 and to increase the pressure in oil chamber 18. While upon increase of pressure in oil chamber 23, the piston 13 will move to the right thus to open the discharge port 25 and to discharge fuel into fuel tank 1. On the contrary, upon drop of pressure in oil chamber 23, the piston 20 will move to the left thus to stop fuel supply from the restrictor 19 and to increase the pressure.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a fuel injection device, and particularly to a fuel injection device suitable for supplying fuel to an electromagnetically operated metering valve provided in an electronically controlled fuel injection pump. be.

[Background of the invention]

In a conventional electronically controlled fuel injection pump as disclosed in Japanese Patent Application Laid-Open No. 5.7-56660, the flow rate of fuel sent from the fuel pumping mechanism to the electromagnetically operated metering valve is proportional to the pump rotation speed. On the other hand, this fuel pressure is controlled by a direct pressure control valve. When the fuel flow rate increases, the opening area of the pressure regulating valve increases, so the amount of deflection of the spring increases and the regulated pressure increases.

In other words, the supplied fuel pressure increases or decreases in proportion to the pump rotation speed, and the amount of fuel metered in the same metering time fluctuates, resulting in problems such as a decrease in control accuracy and performance of the fuel injection pump. There is.

[Purpose of the invention]

An object of the present invention is to provide a fuel injection device that improves the control accuracy and performance of a fuel injection pump.

[Summary of the invention]

In order to achieve the above object, the present invention provides a fuel injection device that includes a pressure regulating valve that controls the fuel pressure from a fuel pumping mechanism, a pressure regulating part equipped with a piston, and a piston controlled by electromagnetic force. It is characterized by comprising a solenoid valve section, and a command to be supplied to the solenoid valve section is fluidly transmitted to a pressure regulating section for control.

[Embodiments of the invention]

An embodiment of the fuel injection device of the present invention will be described below with reference to the drawings.

In Fig. 1, 1 is a fuel tank, 2 is a fuel pumping mechanism, this fuel pumping mechanism 2 sucks fuel from tank 1 and supplies it to an electromagnetically operated metering valve 4, and 3 is a pressure regulating valve. , this pressure regulating valve 3 has a pressure regulating section 10 and a solenoid valve section 1.
1, and the pressure regulating valve 3 regulates the fuel pressure supplied to the metering valve 4.

The fuel supplied to the metering valve 4 is metered to the required amount and sent to the fuel injection pump 5, which increases the pressure to a higher pressure and then supplies it to the fuel injection valve 6. The high-pressure fuel sent to the injection valve 6 is injected into the cylinder of the engine 7 to drive the engine. 8 is a sensor that detects the rotational speed of the fuel injection pump 5, fuel pressure, fuel temperature, etc., and 9 is a calculation device such as a microcomputer that calculates a reference pressure.

FIG. 2 is a detailed view showing the structure of the pressure regulating valve 3, in which the pressure regulating section 10 includes a valve body 12, a piston 13, and a spring 1.
4 as the main component, and a fuel supply port 15. It has a discharge port 16. Further, hydraulic pressures 17, 111) are formed on the left and right sides of the piston 13, and a throttle 19 is formed on the piston 13.
is provided. The solenoid valve section 11 includes a piston 20
, the main components are a solenoid 21 and a spring 22,
An oil chamber 23 is formed on the left side of the piston 20, and this oil chamber 2
3 and the oil chamber 17 communicate through a hole 24.

25 indicates a discharge port.

Next, the operation of the device of the present invention will be explained.

Fuel supplied from the fuel pumping mechanism 2 to the oil chamber 18 via the supply port 15 moves the piston 13 to the right (in the direction of the arrow in the figure) and simultaneously flows into the oil chamber 17 via the throttle 19. At this time, the piston 13 stops at a position where the fuel pressure from the oil chambers 17 and 18 and the force of the spring 14 are balanced. When the pressure in the oil chamber 18 increases, the piston 13
moves further to the right, and the discharge port 16 opens to discharge fuel into the fuel tank 1, so that the pressure in the oil chamber 18 decreases. Conversely, if the pressure in the oil chamber 18 decreases.

The piston 13 moves to the left and the discharge port 16 closes, thereby increasing the pressure in the oil chamber 18.

In this way, the pressure m manufacturing unit 1O has a function of maintaining the fuel pressure in the oil chamber 18 constant regardless of the magnitude of the fuel flow rate by controlling the pressure in the oil chamber 17.

Further, the pressure of the oil chamber 23 acts on the piston 20 of the solenoid valve 11 from the left side, and the force of the spring 22 and the force of the solenoid 21 act on the piston 20 from the right side, and the piston 20 acts at a position where these forces are balanced. Stop. When the pressure in the oil chamber 23 increases, the piston 13 moves to the right, opens the discharge port 25, and discharges the fuel into the fuel tank 1. On the other hand, when the pressure in the oil chamber 23 decreases, the piston 20 moves to the left, stops the flow of fuel from the throttle 19, and increases the pressure. The operation of this piston 20 can be arbitrarily controlled by the force of the solenoid 21.

That is, if the relationship between the command current of the solenoid 21 and the generated force is made clear, the pressure in the oil chamber 23 and, therefore, the pressure in the oil chamber 18 can be arbitrarily controlled. The magnitude of the solenoid 210 command &Y, the sensor 8 detects the fuel injection pump, fuel pressure, fuel temperature, etc., and the calculation device! 9
Calculate the optimum reference pressure by
As described above, the fuel pressure supplied to the electromagnetically operated metering valve 4 can be maintained constant regardless of the rotational speed of the fuel injection pump, the fuel temperature, and the amount of fuel injected.

Therefore, since the amount of fuel metered by the metering valve 4 does not vary during the same metering period, the control accuracy and performance of the fuel injection pump 5 are improved.

〔Effect of the invention〕

According to the fuel pressure control device of the present invention, the fuel pressure supplied to the metering valve can be controlled to an optimal value regardless of the fuel injection pump rotation speed, fuel temperature, fuel injection amount, etc. It is possible to improve control and performance of the pump.

[Brief explanation of the drawing]

FIG. 1 is a supply fuel system diagram for explaining the fuel injection device of the present invention, and FIG. 2 is a sectional view for specifically explaining the configuration of the pressure regulating valve in the fuel injection device of the present invention. 2...Fuel pressure feeding mechanism, 3...Pressure regulating valve, 4...
Metering valve.

Claims (1)

[Scope of Claims] 1. A fuel injection device that measures fuel from a fuel pumping mechanism with a metering valve and supplies it to a fuel injection pump to control fuel injection timing, fuel injection amount, etc. A pressure regulating valve that regulates the fuel pressure from the fuel pumping mechanism is composed of a pressure regulating section with a piston and an electromagnetic valve section with a piston controlled by electromagnetic force, and a command is supplied to the electromagnetic valve section. 1. A fuel injection device characterized in that the pressure is fluidly transmitted to a pressure regulating section for control. 2. The fuel injection device according to claim 1, wherein the electromagnetic force of the electromagnetic valve section is controlled by a command from an arithmetic unit.