JPS58128429A - Fuel feeder - Google Patents

Abstract

PURPOSE:To always attain an appropriate air fuel ratio and dispense with an accelerating pump or the like, by operating a fuel pressure regulator depending on the displacement of an accelerator pedal and by controlling a throttle valve depending on the detected value of fuel pressure and the conditions of an engine and the atmosphere. CONSTITUTION:A signal corresponding to the quantity of operation of an accelerator pedal is applied to the fuel control section 71 of a microprocessor 7. The fuel control section 71 calculates an input train for a fuel pressure regulator (actuator) on the basis of the applied signal to drive the actuator with a solenoid or the like depending on the pressure of fuel to determine the quantity of the fuel which is returned to a fuel tank. At that time, a fuel detecting section 72 estimates the flow rate of the fuel by a table look-up method from the quantity of operation of the accelerator pedal and the pressure at a nozzle which corresponds to said fuel pressure, and the section 72 also measures the actual flow rate of the fuel by a flow sensor. An air quantity control section 73 calculates an appropriate air quantity for the estimated flow rate of the fuel. The degree of opening of a throttle valve is then controlled by an actuator 81.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply system, and particularly to a fuel supply system that can obtain an appropriate air-fuel ratio in response to accelerator operation.

Generally, the fuel amount/supply device for an internal combustion engine changes the opening degree of the throttle valve in response to accelerator operation, detects the resulting amount of intake air, and then delivers fuel commensurate with the amount of air. The so-called air flow priority system, which is designed to obtain an appropriate air-fuel ratio, is common.

However, the conventional method described above uses a series of sequences in which a change in the intake air flow rate is detected and then a corresponding fuel flow rate is determined. For example, during acceleration, fuel is supplied following the increase in the air flow rate. However, during deceleration, because the fuel supply does not follow the decrease in air flow rate, the mixture temporarily becomes richer. is well known, and various correction means are being considered as solutions to this problem. However, each solution has its own advantages and disadvantages, as well as the complexity of the equipment.
It is difficult to completely solve this problem. That is, the air-fuel ratio of the internal combustion engine is such that the amount of fuel is 1 relative to the amount of air taken in.
This is because, of course, the amount of fuel supplied must be changed depending on the operating condition, especially in recent years, exhaust gas, etc., as well as not being determined secondarily.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a fuel supply device that can obtain an appropriate air-fuel ratio at any time in response to accelerator operation.

In the present invention, the operation signal from the accelerator is introduced into the microprocessor to operate the fuel pressure regulator, and at the same time,
The generated fuel pressure is introduced into a microprocessor, and after arithmetic processing is performed that takes into account the operating state and atmospheric conditions, the throttle valve is changed to obtain an appropriate air-fuel ratio at any time.

Examples will be described below with reference to the drawings.

FIG. 1 is an overall block diagram of an embodiment of a fuel supply apparatus according to the present invention, FIG. 2 is a block diagram of a calculation system, and FIG. 3 is a flowchart for calculation processing.

In FIG. 1, l is an intake pipe connected to an air cleaner (not shown). 2 is a nozzle and a fuel pressure regulator 3
It is connected to and opens into the venturi 4. Reference numeral 5 denotes a fuel pump which pumps up the fuel in the fail tank 6, and the pumped up fuel is branched through the fuel pressure regulator 3, one to the nozzle 2 side and the other to the fail tank 6 side. Therefore, some of the fuel is fed to the fail pump 6 according to the duty ratio depending on the operating conditions.
It is circulated to the side. Note that the fuel pressure adjusting means may be arbitrarily selected, such as electromagnetic means such as a solenoid, or a needle inserted into and taken out of a jet using a linear step motor or the like. Reference numeral 7 denotes a microprocessor (hereinafter referred to as MPU), which executes a series of arithmetic operations taking into account various conditions according to a pre-built-in program. 8
is the throttle valve. The MPU receives the suction pipe internal pressure from the suction pressure sensor PB, the nozzle pressure from the nozzle pressure sensor Pn, the fuel pressure from the fuel pressure sensor Pr, and the butterfly valve opening θ·th from the throttle valve 8.

Engine parameters such as rotational speed and water temperature, and atmospheric conditions such as air temperature and atmospheric pressure are respectively input.

In addition, as a fuel pressure adjustment means during cranking,
As an initial condition to obtain the necessary air-fuel mixture at startup, the opening of the throttle valve is set to the first idle opening, which is slightly more open than when idling, and the fuel pressure is adjusted in accordance with the calculation results in subsequent operating conditions. become.

The calculation system will be explained with reference to FIG. MPU7 shown
In the fuel control system 71, an operation signal from the accelerator, that is, an accelerator amount θP is input, and an input sequence to the fuel pressure adjustment system (actuator section) is calculated according to the θP. As a result, the actuator section is energized by a solenoid or the like according to the fuel pressure Pf = F (θP), and the amount of fuel returned to the fail tank is determined.
72 is a fuel detection system which detects a nozzle pressure P according to the fuel pressure.
The fuel flow rate QFuel is fully estimated using the table lookup method from i and the accelerator amount θP, and the flow rate is directly measured using a fail flow sensor. Reference numeral 73 denotes an air amount control system, which controls the appropriate air amount Q for the fuel flow rate QFuel.
air=4.QFu e l is calculated, and the input string to the actuator section 81 is calculated. Here, the actuator section controls the opening and closing of the throttle valve via, for example, a motor or a step motor in accordance with the calculated input string. The series of calculations described above are also inputted with engine parameters and atmospheric conditions from the engine 9, and are executed according to the program while taking these into consideration.

Next, the arithmetic processing program will be explained with reference to the flowchart shown in FIG. FIG. 3(a) is an air-fuel ratio calculation program. First, an operation mode determination process is performed at 5teplO. That is, this is engine state determination, and for example, determination processing such as idle link, acceleration, deceleration, and cranking is performed. In step 11, direct measurement processing is performed by estimating the fuel flow rate and performing a fuel flow test. At 3tep12, the appropriate air-fuel ratio (A/
An air amount calculation process is performed to obtain F). 5t
In ep 13, calculation processing of the air amount Qhir = Qair In step 14, according to the revised air amount, the position of the air regulating valve (butterfly no (loop, etc.) It is converted into a pulse rate and processed as input to the throttle drive motor.

FIG. 3(b) is a flowchart for checking the operating status at any time, for example, periodically or irregularly, and for making corrections in the flowchart shown in FIG. 3(a).
FIG. 4(c) is a flowchart for changing the output of the input string to the motor, for example, periodically and determining the optimum value according to the operating condition. Moreover, the above-mentioned figure 3(a),
It goes without saying that the programs (b) and (c) do not exist independently, and are executed in parallel by interrupts.

As explained above, according to the present invention, the fuel pressure is changed by the operation signal from the accelerator, and the throttle valve is operated accordingly, and this is calculated by a microprocessor that takes into account the engine state and atmospheric conditions. Since this is performed through processing, the electronic fuel supply device can provide an air-fuel ratio with no excess or deficiency.

[Brief explanation of the drawing]

FIG. 1 is an overall block diagram of an embodiment of an electronic fuel supply apparatus according to the present invention, FIG. 2 is a block diagram of a calculation system, and FIG. 3 is a flowchart for calculation processing. 1... Intake pipe 2... Nozzle 3...
Fuel pressure regulator 4...Venturi 5...Fuel pump 6...Fail tank 7...Microprocessor 8...Throttle valve 9.
...Engine 31...Fuel pressure adjustment system 71
... Fuel control system 72 ... Fuel detection system 73
... Air flow control system 81 ... Air metering system patent applicant Mikuni Kogyo Co., Ltd. agent Patent attorney Norio Ishii) Ma 3 diagram (α) (1)) (C)

Claims (1)

[Claims] In a fuel supply system that can maintain the air-fuel ratio of an internal combustion engine at any time, the fuel pressure regulator is actuated by introducing accelerator displacement into the microprocessor, and the fuel pressure detected after the adjustment is reintroduced to the microprocessor to control the engine. Perform calculation processing taking into account the state and atmospheric conditions,
A fuel supply device characterized by adjusting a throttle valve.