JPS5827830A - Injecting device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the responsiveness in an unsteady state of an engine by a method wherein an injection pulse width is calculated based on a signal from detecting means of the unsteady state of the engine, thereby controlling the operation of an injection valve. CONSTITUTION:In a central control and operation unit 8 which receives signals from an intake air amount sensor 4 provided upstream a throttle valve 5 of the engine 1, a pressure sensor 7 at downstream thereof and an engine speed sensor 12, and outputs a signal to control a fuel injection valve 6 through a drive circuit 9, it is discriminated whether the engine 1 is driven steadily or not based on the information from the sensor 4 and the like, and if the engine is in an unsteady state, an injection pulse width is calculated and a timer is set to generate an interruption after a certain period of time. When the interruption enters in response to the signal from the engine speed sensor 12, the fuel injection valve is opened for predetermined period of time. Further, in case of the interruption of the timer being set, the valve 6 is opened at a certain pulse width or the pulse width corresponding to the input from the sensor 4 and the like. Thus, the fuel injection valve 6 can be opened at a particular time interval when the engine 1 is driven in an unsteady condition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine fuel injection system having an electromagnetically operated injection valve, which is operated by a control device as a function of the operating parameters of the internal combustion engine.

Conventionally, this type of method for increasing or decreasing the amount of fuel in an unsteady state of an internal combustion engine involves controlling the opening time width of an injection valve that opens in synchronization with the rotation of the engine in accordance with the operating parameters of the engine. It is carried out by ° However, in this type of device that supplies fuel in synchronization with rotation, the injection pulse interval is as long as 80 m5ec when accelerating from a low rotation of about 1000 rotations, and the time required to detect acceleration and the acceleration cannot be detected. When considering the time from when the injection pulse width is reflected until it is reflected in the injection pulse width, the delay time will significantly appear in the decrease in responsiveness. Therefore, it was necessary to add a special acceleration correction mechanism. In addition, with conventional devices, the injection pulse width is increased to increase the amount of fuel when starting the engine and when warming up after starting, but when the engine is at a low temperature such as when starting or warming up, the injected fuel is sufficient. This has the disadvantage that it does not vaporize and flows along the wall of the intake pipe, making it difficult to obtain a mixture with a predetermined air-fuel ratio even if a large amount of fuel is supplied.

Furthermore, during deceleration, it is necessary to cut or reduce fuel during deceleration, in addition to the above-mentioned operations such as acceleration, starting, and warming up.

In other words, in conventional devices, fuel is injected in synchronization with engine rotation, so a special acceleration correction groove is required during acceleration, and even when a large amount of fuel is supplied during startup and warm-up, the predetermined air-fuel ratio cannot be maintained. The disadvantage is that it is not possible to obtain a mixture of
Furthermore, when decelerating, fuel needs to be cut or reduced, which is different from when accelerating or starting and warming up.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and includes a means for calculating the pulse width of an injection pulse according to the operating parameters of an internal combustion engine, and a means for calculating the pulse width of the injection pulse according to the operating parameters of the internal combustion engine. means for calculating the interval;
Equipped with an engine state detection means for detecting the operating state of the engine,
When the engine is in an emergency state, the signal from the means for calculating the pulse interval of the injection pulse or the injection pulse (
By opening the injection valve based on signals from both the means for calculating the 117 width and the means for calculating the pulse interval of the injection pulse, the minimum necessary amount of fuel can be accelerated with good responsiveness when the engine is not steady. It is an object of the present invention to provide a very useful internal combustion engine fuel injection device that can supply fuel to an engine by a series of calculation operations regardless of whether it is decelerating, starting, warming up, or the like.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is an overall configuration diagram showing one embodiment of the present invention. In the figure, 1 is an internal combustion engine, 2 is its intake pipe, and includes an air cleaner 8 for cleaning intake air, a throttle valve 5 for acceleration control, and The engine 1 includes an intake air amount sensor 4, a pressure sensor 7, and the like that measure the amount of intake air taken into the engine 1. Reference numeral 8 denotes a central control calculation section, which is composed of a microcomputer, .about. converters, a timer, etc., and includes injection pulse width calculation means, injection pulse interval calculation means, engine state detection means, and the like. The injection pulse output from the central control calculation unit 8 is amplified by the drive circuit 9, and the fuel injection valve 6 is operated for that period of time.
is opening its doors. Since pressurized fuel at a constant pressure is supplied to the fuel injection valve 6 disposed in the intake system of the engine 1 from a fuel pump (not shown), the amount of fuel corresponding to the valve opening time is supplied to the engine 1. Supplied. The central control calculation section 8
represents the detection signals from the engine 1's cooling water temperature sensor 10, intake temperature sensor 11, rotation sensor 12, intake air amount sensor 4, intake negative pressure sensor 7, and various sensors such as the air-fuel ratio sensor, throttle sensor, and starter sensor. The received signal is converted into a digital signal, and the calculation of the injection pulse width or the injection pulse interval is performed by software based on a predetermined program.

Next, processing operations in the microcomputer in the central control calculation section 8 will be explained with reference to the flowchart of FIG. In FIG. 2, the arithmetic processing includes a main routine that repeats in a loop and an interrupt routine for issuing injection pulses.

First, arithmetic processing of the main routine is started at main program start 100, and at processing step 101 the microcomputer is set to an initial state. Next, in processing step 102, input information from various sensors is read, and in processing step 108, it is determined whether the engine is in steady operation or in unsteady operation such as starting or acceleration. In processing step 104, an injection pulse interval is calculated according to input information from various sensors, and in processing step 105, an interrupt timer is set so that an interrupt process occurs after the time of the injection pulse interval calculated in step 104. When the other engine is in steady operation, process step 1
The process proceeds to step 107 without going through steps 04 and 105, and it is determined whether or not to execute an interrupt process to open the injection valve in synchronization with the rotation, and in step 108, an injection pulse is generated according to input information from various sensors. Calculate the width and perform the processing step 10
Return to 2. The arithmetic processing of the main routine is performed in such a loop.

If a rotation synchronization interrupt is set in processing step 106, an interrupt routine is executed to accept the interrupt with a synchronization pulse from the rotation sensor and open the injection valve 6 for the time calculated in step 107. processing is started.

In the interrupt routine, when an interrupt is accepted, the main routine processing is temporarily stopped, the interrupt processing is executed, and after the interrupt processing is completed, the suspended main routine processing is resumed. Interrupt processing is started at interrupt reception 200 due to the generation of the synchronization pulse, and after the injection valve 6 is opened for the time width calculated at step 107, processing step 2
Upon return of 02, the main routine arithmetic processing is restarted. Similarly, if the interrupt by the interrupt timer is lofted in step 105, step 104
After the injection pulse interval calculated in , interrupt processing is started at interrupt reception 800 based on a signal from the timer, and the injection valve 6 is opened with a constant pulse width or a predetermined pulse width according to input from various sensors. After this, the main routine arithmetic processing is restarted by returning to processing step 802.

Next, the operation of the above configuration will be explained in relation to the waveform of the injection pulse shown in FIG. 8. First, when an ignition switch (not shown) is turned on to start the internal combustion engine, power is supplied to the entire device, the central control calculation unit 8 starts software operation, and in the main routine shown in FIG. The arithmetic processing returns to processing step 102 via steps 108 to 108 and is repeated. Following this state, when the starter is operated to start the engine 1, the engine is determined to be in an unsteady state at processing step 106, a pulse interval is calculated at processing step 104, and an interrupt timer is set at processing step 105. is set. In this case, if the rotation synchronization interrupt in processing step 106 is set to be executed, as shown in FIG. The injection pulses are added. Even after the start has been completed and the engine is being warmed up, processing step 108 continues
is considered to be an unsteady state, so the fuel injection pulse is as shown in Figure 8 (b
), the injection valve 1 is opened by an injection pulse that is the sum of an injection pulse synchronized with the rotation and an injection pulse whose pulse interval is calculated in an unsteady state. After the warm-up of the engine 1 is completed, it is determined that the engine is in steady operation at step 108, so the arithmetic processing is executed without steps 104 and 105. Since processing step 106 is set to accept rotation synchronization interrupts during steady operation, injection is performed in synchronization with the rotation and with the injection pulse width calculated in processing step 107, as shown in FIG. 8(a). Valve 6 is opened. Furthermore, when the engine 1 accelerates, processing step 106 determines that it is in an unsteady state, so the injection pulse is synchronized with the rotation as shown in Fig. 2, etc., as in the case of startup and warm-up.
The injection pulse with the injection pulse width calculated in step 7 and the injection pulse interval calculated in processing step 104 are calculated, and the pulse width is constant or an injection pulse with a predetermined pulse width depending on the operating parameters of the engine I is added. The injection valve is opened by the pulse. Furthermore, when the engine 1 is decelerating, the pulse interval is calculated in step 106, assuming that it is in an unsteady state, but in this case, the interrupt synchronized with rotation is set not to be executed in step 106, so as shown in FIG. Calculated in processing step 104 as shown in C),
The injection valve 6 is opened only by an injection pulse having a cycle longer than the signal interval of the rotation sensor 12.

In the above embodiment, the means for calculating the injection pulse width, the means for calculating the injection pulse interval, and the means for detecting the engine state are executed by a microcomputer using software, but these means may be individually executed by a hardware circuit or the like. Needless to say, the same effect can be expected even if the configuration is configured.

As described above, according to the present invention, there are provided a means for calculating the pulse width of the injection pulse according to the operating parameters of the internal combustion engine, a means for calculating the pulse interval of the injection pulses according to the operating parameters, and a means for calculating the pulse width of the injection pulse according to the operating parameters. An engine state detection means is provided for detecting the state, and when the engine is unsteady, a signal from the means for calculating the pulse interval of the injection pulse, or a means for calculating the injection pulse nohalus width and a means for calculating the pulse interval of the injection pulse is provided. Since the injection valve is opened by signals from both of Since the required amount of fuel is supplied without time delay, acceleration performance with sufficient responsiveness can be obtained without a special acceleration correction mechanism.

In addition, when the special engine for starting and warming up is low temperature as in the past,
In some cases, the fuel is not vaporized sufficiently, and in order to obtain a mixture with a predetermined air-fuel ratio, too much fuel is supplied at once, resulting in the fuel flowing down the wall of the intake pipe. However, according to the present invention, since the fuel is supplied in several parts during startup and warm-up, the fuel is well atomized and a predetermined air-fuel ratio can be obtained with a small amount of fuel. moreover,
For fuel during deceleration, if the signal from the means for calculating the injection pulse width is ignored and the means for calculating the pulse interval of the injection pulse is calculated so that the pulse interval is sufficiently long,
The method of cutting or reducing fuel during deceleration also applies to acceleration,
This can be done through the same series of operations as starting, warming up, etc., resulting in a simpler configuration.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIG. 2 is a flowchart showing software of a microcomputer in the central control calculation section in FIG. 1, and FIG. 8 is an injection valve according to the present invention. FIG. In the figure, 1... internal combustion engine, 4... intake air amount sensor, 6...
...Electromagnetic injection valve, 7.. Negative pressure sensor, 8.. Central control calculation unit, 10.. Cooling water temperature sensor, 11.. Intake temperature sensor, 12.. Rotation sensor, Agent Makoto Kazuno - Figure 1 Figure 2 Figure 3 (a) (b) (Cλ

Claims (1)

[Scope of Claims] 1. An electromagnetically operated injection valve, means for calculating the pulse width of the injection pulse according to the operating parameters of the internal combustion engine, and means for calculating the pulse width of the injection pulse according to the operating parameters. A means for calculating the interval, and an engine state detection means for detecting the state of the engine during steady operation and the state during non-steady operation such as acceleration, deceleration, and starting, and in response to a signal from the engine state detection means, An internal combustion engine fuel injection device, characterized in that the injection valve is opened by at least one of a means for calculating a pulse width of the injection pulse and a means for calculating a pulse interval of the injection pulse. 2. By means of a signal from means for calculating the pulse interval of the injection pulse during at least one engine state among engine acceleration, deceleration, startup, and warm-up, or
2. The internal combustion engine according to claim 1, wherein the injection valve is opened by both the means for calculating the pulse interval of the injection pulse and the means for calculating the pulse interval of the injection pulse. Fuel injection device.