JPS62129541A - Fuel injection system for engine - Google Patents

Abstract

PURPOSE:To aim at improvement in both fuel consumption and emission properties, by constituting a fuel injection system so as to stop the operation of a fuel injection valve at a time when such a fact that pressure of fuel to the valve drops to less than the specified value at the time of engine starting is detected. CONSTITUTION:This fuel injection system sprays fuel out of a fuel injection valve 12 after pressure of the fuel to be fed out of a fuel pump 13 via a fuel passage 16 is regulated to the specified value by a pressure regulator 18. In this case, there are provided with a starting time detecting device 20, detecting the time of engine starting, and a fuel pressure detecting device 19, detecting the extent of fuel pressure in the said fuel passage 16. And, when the engine starting is detected as well as when a fact that fuel pressure is less than the specified value is detected, the fuel injection value 12 is controlled so as to stop its operation by a stopping device 22. With this constituting, an increase in fuel consumption and an unburned component at the time of starting after leaving it intact for a long period are prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fuel injection +34 device for an engine, and particularly to a fuel injection +34 device for an engine, and in particular to
It's about control.

(Prior Art) Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 57-210137, a fuel injection valve is provided to inject and supply fuel, and when the engine is started, a fuel injection 0-1 valve is used based on engine cooling*. Spray from! Fuel injection devices are known that increase the amount of fuel to ensure good startability. Since the amount of fuel injected by the fuel injection valve is usually determined by the amount of the fuel injection valve, the valve opening time, and the fuel pressure,
It is necessary to keep the pressure of fuel supplied from the fuel pump to the fuel injection valve constant. Therefore, the pressure of the fuel from the fuel pump is regulated to a predetermined value using a pressure regulator, and the pressure is then supplied to the fuel injection 1>1 valve.

(Problem to be solved by the invention) By the way, if an engine equipped with such a fuel injection device is left unoperated for a long period of time (for example, 1 to 2 months), the fuel pump may be disconnected during that time. The fuel pressure in the fuel passage between the fuel injection valve and the fuel injection valve may leak from the fuel pump or the like and drop below a predetermined value. When starting the engine in such a case, initially, only a small amount of fuel is injected through the fuel injection valve due to the drop in fuel pressure, so ignition does not occur, and then the fuel pump operates to lower the fuel pressure to the specified level. Only when the value is reached will the ignition occur. Therefore, during this period, fuel is consumed unnecessarily by injecting a small amount of fuel even though it does not ignite, and
Unexpected components such as +-I C are generated and the emission performance deteriorates.

The present invention has been made in view of this point, and when starting when the fuel pressure to the fuel injection valve has decreased due to being left unused for a long period of time, the direct operation of the fuel injection valve is stopped.
By activating the fuel pressure when it reaches a predetermined value, unnecessary fuel injection is stopped when ignition does not occur, and an increase in the fuel layer 9ffi is prevented.
The purpose is to prevent deterioration of emissions due to the generation of unnatural components.

(Means for solving the problem) In order to achieve the above object, the solution taken by the present invention is as shown in FIG.
This is a fuel injection system for an engine in which the pressure of fuel fed through a pressure regulator 6 is regulated to a predetermined value by a pressure regulator 18, and the fuel is injected from a fuel injection valve 12.

That is, it includes a starting detection means 20 for detecting when the engine is started, and one fuel pressure detection means for detecting the fuel pressure in the fuel passage 16, and both of these detection means 19 are provided.
．． The engine is equipped with a stop means 22 which receives an output of 20 and stops the operation of the fuel injection valve 12 when the fuel pressure in the fuel passage 16 is less than a predetermined one cycle during startup.

(Function) With the above configuration, in the present invention, when the engine is started, the operation of the fuel injection valve 12 is strongly stopped when the fuel pressure in the fuel passage 16 is below a predetermined value.
Unnecessary injection of fuel that does not lead to ignition from the fuel injection valve 12 due to the decrease in fuel pressure is eliminated. As a result, the fuel temperature 'f! tI!
This will prevent an increase in i and a deterioration in emissions. Thereafter, when the fuel pressure reaches a predetermined value due to the operation of the fuel pump 13, a predetermined amount of fuel is supplied to the fuel injection valve 1.
2, and ignition is successful.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings from FIG. 2 onwards.

FIG. 2 schematically shows an overall system according to an embodiment of the present invention, in which 1 is an engine, and the engine 1 has a combustion chamber 3 whose volume is variable by a reciprocating piston 2. A crankshaft 5 is connected to the crankshaft 5 via a connecting rod 4, and a starter motor 6 is connected to the crankshaft 5 via a gear mechanism G.
The operation of the starter motor 6 causes the crankshaft 5 to rotate and the piston 2 to reciprocate, thereby making it possible to start the engine 1. Further, 7 is an intake passage for supplying intake air to the combustion chamber 3 of the engine 1, and 8 is an exhaust passage for discharging exhaust gas from the combustion chamber 3. An intake valve 9 is provided at the frontage, and an exhaust valve 10 is provided at the opening of the exhaust passage 8 to the combustion chamber 3.
are arranged respectively. 1) is a spark plug disposed facing the combustion chamber 3.

Further, 12 is a fuel injection valve disposed in the intake passage 7 to inject and supply fuel, and 13 is a fuel pump, the suction port of the fuel pump 13 communicating with the inside of the fuel tank 15 via the suction passage 14. On the other hand, the discharge port of the fuel pump 13 is connected to the fuel injection valve 12 through the fuel passage '1G.
The fuel pump 13 supplies the fuel in the fuel tank 15 to the fuel injection valve 12 via the fuel passage 16. Further, a return passage 17 is branched from the middle of the fuel passage 16, and the other end is connected to the fuel tank 15, and an intake passage 7 is located near the branching part of the return passage 17 and the fuel passage 16.
A pressure regulator 18 whose relief pressure value changes according to the intake negative pressure of the fuel tank 15 is interposed. By relieving the fuel pump 13, the pressure of the fuel 1) from the fuel pump 13 is regulated to a predetermined value according to the intake negative pressure, so that the fuel injection valve 12 injects a predetermined amount of fuel m.

Furthermore, one is a fuel pressure sensor as a fuel pressure detection means for detecting the fuel pressure in the fuel passage 16, and 20 is a fuel pressure sensor for detecting the fuel pressure in the fuel passage 16;
The starter switch serves as a starting detection means for detecting the starting time of the starter motor 6, the spark plug 1), the fuel injection valve 12, and the fuel pressure signal from the fuel pressure sensor 19 and the starter signal from the starter switch 20.
A control unit 1-214, which includes a CPU and the like, controls the operation of the fuel pump 13.

The opening and opening at the time of starting by the control unit 21 will be explained with reference to the flowchart in FIG. (When + and i are input, the fuel pump 1 is instructed to operate the fuel pump 13 in step S2.
Outputs ONN signal to 3. Next, in step S3, the fuel pressure 1i1) I P + is read from the fuel pressure sensor 19, and in step S4, it is determined whether or not this fuel pressure value P1 is larger than the set fuel pressure Pa (that is, the relief pressure value of the pressure regulator 18). , P1≦Pl), when the result is No, the process returns to step 82 and the fuel pressure is increased. And P
+ When Pa becomes YES, O is sent to the starter motor 6 to operate the starter motor control in step S5.
At the same time as outputting the N signal, an O signal is sent to the fuel injection valve 12 and the spark plug 1) to operate them in step S6.
Outputs N signal. According to the above flow, when the fuel pressure in the fuel passage 16 is below a predetermined value during startup, the operation of the fuel injection valve 12 and the starter motor 6 is stopped, and when the predetermined one shift or more is reached, the operation of the fuel injection valve 12 and the starter motor 6 is stopped. A stopping means 22 is configured to start the operation of the motor 6.

Therefore, in the above embodiment, as shown in FIG. 4, when the scooter switch 20 is turned on at engine start, the fuel pump 13 is simultaneously operated, but the starter motor 6 and the fuel injection valve 12 are operated at the fuel pressure. The operation remains stopped until the fuel pressure (in) from the sensor 19 (that is, the fuel pressure in the fuel passage 16) reaches a predetermined value.

During this time, unnecessary fuel r1 that does not lead to ignition due to the drop in fuel pressure is prevented from being injected from the fuel injection valve 12, so that the fuel consumption that occurs at startup after being left unused for a long period of time is prevented. It is possible to improve fuel efficiency and emissions by preventing an increase in the amount of fuel and preventing the generation of unnatural components. Furthermore, consumption of the power required to rotate the starter motor 6 during a predetermined period of time before ignition is prevented, and the durability of the battery can be improved.

When the fuel pressure in the fuel passage 16 reaches a predetermined value due to the operation of the fuel pump 13, the starter motor 6 and the fuel injection valve 12 start operating.

At that time, a predetermined amount of fuel is injected and supplied from the fuel injection valve 12 with weight increase correction based on the engine cooling water temperature (engine temperature), so that ignition is properly performed by ignition of the spark plug 1). Start #h.

After starting, when the starter motor 6 J3 and the starter switch 20 are turned off, the fuel injection valve 1 is turned off.
From No. 2 onwards, the fuel is injected in an amount corresponding to the normal operating condition without being corrected to increase the amount at startup as described above.

(Effects of the Invention) As described above, according to the present invention, when the fuel pressure to the fuel injection valve is lower than the predetermined value 1) when starting the engine, the fuel injection valve is activated. Since the engine is stopped, it is possible to prevent an increase in fuel consumption and the generation of unforeseen components when the engine is started after being left unused for a long period of time, thereby improving fuel efficiency and emissions.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 4 show embodiments of the present invention, in which FIG. 2 is an overall schematic diagram, FIG. 3 is a flowchart showing the operation of the control unit, and FIG. 4 is an explanatory diagram of the operation. 1... Engine, 12... Fuel injection valve, 13...
Fuel pump, 16...Fuel passage, 18...Pressure regulator, 19...Fuel pressure sensor, 20...Starter switch, 21...Control unit, 22...
・Stopping means. Patent applicant Mazda Motor Corporation Representative Patent attorney Former fH Kodai 1
Figure 4Figure 3

Claims (1)

[Claims] (1) A fuel injection valve that injects fuel, a fuel pump that supplies fuel to the fuel injection valve via a fuel passage, and a pressure regulator that regulates the pressure of the fuel in the fuel passage to a predetermined value. In a fuel injection device for an engine, a starting detecting means detects when the engine starts, a fuel pressure detecting means detects fuel pressure in the fuel passage, and a fuel injection device detects the fuel in the fuel passage when the engine starts. A fuel injection device for an engine, comprising a stop means for stopping the operation of the fuel injection valve when the pressure is below a predetermined value.