JPS60147548A - Electronically controlled fuel injection appatatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent occurrence of vapor-lock and to thereby improve the starting performance of an engine, by comparing the temperature of cooling water and the temperature of intake air with respective reference values at the time of starting the engine, and in case that the engine temperature is high, injecting fuel under high-temperature starting mode for a prescribed while. CONSTITUTION:In operation of an engine, the value Tw measured by a sensor 17 for detecting the temperature of cooling water is compared with a reference value Tw at a means for comparing the temperature of cooling water. In case of Tw<=TW, the output signal of said comparing means is applied to a means for instructing ordinary starting mode, wheareas in case of Tw>TW, the output signal is applied to a means for comparing the temperature of intake air. Further, in case of Tw>TW, the value Ta measured by a sensor 23 for detecting the temperature of intake air is compared with a reference value TA. In case of Ta<TA, the output signal of said comparing means is applied to the means for instructing ordinary starting mode, whereas in case of Ta>=TA, the output signal is applied to a means for instruction high-temperature starting mode. Through operation of said means for instructing high-temperature starting mode, a fuel injection valve 13 is controlled under the high temperature starting mode for a certain while determined by the output signal of an engine-speed sensor 9, and the starting mode is switched to the ordinary starting mode after the elapse of said certain while.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to an electronically controlled fuel injection device for an internal combustion engine, and more particularly to a device for calculating and controlling a fuel injection mode at the time of starting an internal combustion engine. In the following description, the internal combustion engine will be abbreviated as engine.

(Prior Art) First, with reference to FIG. 1 showing the general configuration of the conventional device and the device of the present invention] a, an example of a conventional electronically controlled fuel injection device that is controlled using a microcomputer. The configuration of is explained.

In FIG. 1, the engine is indicated generally at 7, 1 is its cylinder and 2 is the cylinder head. 3 is a piston equipped with a Bismy cylinder 4, which moves forward in the cylinder 1, transmits the scum pressure caused by the explosion of the air-fuel mixture in the 1F contraction stroke to the connecting rod 5, and rotates the crankshaft (not shown). Reference numeral 6 denotes a distributor, in which is built a rotation sensor 9 attached to a rotating shaft that rotates in synchronization with the rotation of the crankshaft. 8 is an ignition coil; 10 1 is an intake pipe, 11 is an exhaust pipe, 12 is an air cleaner, and 13 is a fuel injection valve that is attached to a portion of the intake pipe 10 near the intake bow 1 of the engine 7 and is opened and closed electromagnetically. The control unit 1 includes an electronic circuit and a microcomputer, and specifies the fuel injection mode and controls the fuel injection time, that is, the fuel injection valve 13.
0 energization time is calculated, and the fuel injection valve 13 and fuel pump 1 are
Generates a drive signal such as 5. 16 is an intake air amount sensor that detects the intake air amount in the intake pipe 10, 17 is a coolant temperature sensor that detects the coolant temperature of the engine 7, and 18 is,
A between the ignition switch that opens and closes the power supply to the control unit 14, etc., and the starting bag of the engine 7.
It is a key switch with a starter switch that turns on and off. 19 is a fuel tank, 20 is a fuel pressure regulating valve for keeping the fuel pressure constant, 21 is a fuel pipe communicating between the fuel pressure regulating valve 20 and the fuel injection valve 13, and 22 is a fuel return pipe. In addition, 23 is an air cleaner 12
This is an intake air temperature sensor attached to one part of the engine to detect the temperature of the intake air.

In the above configuration, each time the engine 7 receives ¥100 of fuel
The amount of fuel injection is controlled by the length of time that the fuel A';1 injection valve 13 is open based on signals sent from the control units 1-14.

The amount of fuel oil +1 injection is increased depending on the engine condition, especially in low fuel conditions where fuel vaporization is low, and in situations where the cooling water temperature is high and the fuel temperature is also high. The amount is increased when it is necessary to improve the restartability of the engine in a situation where the air-fuel mixture becomes stale. Here, paper is generated more when the vehicle is stopped than when it is running, and when the cooling fan is stopped due to the engine stopping and when the vehicle is running.
ill JJ, approximately 20 minutes after the vehicle stopped due to the disappearance of 1
In the event that a minute has passed, the fuel temperature will drop to one level, and paper is likely to form in the fuel piping. In addition, at this time, the fuel F81 temperature may even become higher than the engine cooling water crystallinity. When paper is generated in this way, the air-fuel mixture supplied to the engine becomes diluted, so if the amount of fuel is not increased when restarting the engine, startability will deteriorate.

As a conventional device, for example,
No. 4 (Japanese Patent Application No. 157464/1986) is equipped with a fuel temperature sensor that detects the fuel temperature in the fuel pipe, and when the detected temperature of this fuel starvation sensor exceeds a preset temperature. C that determines whether the fuel injection amount is increased and controls the oil cylinder to increase the amount of fuel injection.
An electronically controlled fuel injection nozzle 4 device is disclosed that incorporates a control unit that includes a PU.

However, in such conventional devices, when calculating the fuel injection time at the time of starting the engine, the failure of the fuel injection 11Fiffl takes into account the high cooling water temperature and intake air temperature with respect to the -[engine r1 movement in the high temperature state. If this method is insufficient, the generation of a large amount of paper may cause a paper lock, which may make it impossible to start the engine.

(Objectives and Summary of the Invention) In order to solve the problem of deterioration of engine startability due to the generation of paper, the present invention aims to improve the cooling water temperature and intake air temperature used to determine the state at the time of starting the engine. Equipped with temperature determination means, when it is determined that the temperature is high,
An object of the present invention is to provide an electronically controlled fuel injection nozzle device for an engine having a configuration in which fuel injection is performed in a high temperature starting mode for a predetermined period of time, and after a predetermined period of time, the fuel injection is switched to a normal starting mode.

The control unit included in the electronically controlled fuel injection system for an engine according to the present invention incorporates a microcontroller and its input/output elements.

At the same time, it compares the detected values of cooling water temperature and intake air temperature with judgment reference values to determine the state of the engine at the time of starting, and specifies the optimal fuel injection mode, so as to achieve the above purpose. When it is determined that the engine is in a high temperature state, fuel IM m is carried out for a predetermined period of time in the high temperature start mode, and after the elapse of the predetermined period of time,
It includes fuel injection control means according to the present invention configured to shift to a conventional normal starting mode.

(Configuration of the device according to the present invention) Next, the configuration of the fuel injection q.1 control means according to the present invention included in the control unit 14 in FIG. 1 will be explained as follows. The explanation will be given with reference to the functional block diagram of FIG. 4, which is illustrated with reference to FIG.

In FIG. 4, the output line of the cooling water temperature Hinley 17 shown in FIG. It's dark.

The cooling water wetness comparison means compares the value of the cooling water temperature detection signal output from the cooling water temperature sensor 17 with a cooling water temperature reference value,
A first output line for sending out a first output signal generated when the former is less than or equal to the latter is normally led to the input end of the starting mode designation means, and a first output line for sending out a second output signal generated when the former exceeds the latter. The second output line is led to the input end of the intake temperature comparison means. Further, the output end of the normal start mode designation means is connected to a fuel input terminal that outputs a drive signal for the fuel injection valve 13.
11 injection Q1 is connected to the input end of the valve driving means.

The intake air temperature comparison means compares the value of the intake air temperature detection signal outputted from the intake air temperature sensor 23 with the intake air temperature reference value in response to the second output signal outputted from the cooling water temperature comparison means, and the former compares with the intake air temperature reference value. A first output line that sends out a first output signal generated when the former is less than or equal to the latter is normally led to the input end of the start mode designation means, and a second output line that sends out a second output signal that is generated when the former is greater than or equal to the latter. is led to one input of the hot start mode designation means.

Next, the high temperature start mode specifying means sends out a first output signal specifying operation in the high temperature start mode, which is generated for a predetermined period of time in response to the second output signal output from the intake temperature comparison means. The output line is led to the input end of the fuel injection valve driving means, and after the above-mentioned predetermined period has elapsed, the second output line t sends out a second output signal generated by the high starting mode specifying means to switch to the normal starting mode. It is asked at the input end of the specification means.

The output line of the rotation sensor 9 shown in FIG. 1 is shown connected to the other input terminal of the high temperature start mode designation means. As will be described later, this is used as a signal source for defining the predetermined period during which the 8-temperature start mode designating means generates the first output, for example, by the set number of 1N fuel injections. The case where C is used is shown.

Here, the above-mentioned fuel according to the present invention! The Fit patrol control means includes a cooling water temperature comparison means, an intake temperature comparison means, a normal starting mode specifying means, and a high temperature starting mode specifying means shown in FIG.
and a fuel injection valve driving means. and,
The above fuel! I cooling water temperature comparison means in the patrol control means;
The intake temperature comparing means, the normal starting mode specifying means, and the high temperature starting mode specifying means are 14 elements of the microcomputer included in the control unit 14, and the fuel injection valve driving means constitutes an output element thereof. There is.

(Operation of the device according to the present invention) The operation of the fuel injection control means according to the present invention having the above-mentioned configuration will be explained with reference to FIGS. 2 and 3.

FIG. 2 is a control flow A7-1 to illustrating the operation of the fuel injection control means according to the present invention. First, step 1
When power is supplied to the control unit 14 by turning on the key switch 18 shown in FIG. 1 at step 00, initial settings are performed at step 101, and then step 1
At 02, the cooling water temperature signal is sent from the cooling water temperature lens 17,
An intake temperature signal is input from the intake temperature sensor 23. In step 103, the cooling water humidity is compared with the judgment reference value Tw, and when the cooling water temperature is less than the judgment reference value lower W, the process proceeds to step 104, in which the humidity is determined according to the condition of the engine, as is conventionally known. Normal start mode operation is specified, which is a valve time fuel injection mode. Cooling water temperature is the judgment reference value Tw
If it exceeds , proceed to step 105. Step 10
5, the intake air temperature is compared with the determination reference value TA,
Judgment Criteria (If there is no whirlpool under lTTTA, the process proceeds to step 104, and the operation in the normal starting mode is specified. If the intake air temperature is equal to or higher than the judgment reference value TA, it is determined that the engine is currently in a high temperature state, and the process proceeds to step 106. In order to control the fuel flow, a high-temperature start mode operation is specified, such as a fuel injection mode using a long valve opening time pulse, in which the fuel injection occurs for a predetermined period of time. After this, the control process proceeds to step 104, and from then on, normal startup mode operation is designated.

Furthermore, as can be seen from FIG.
The signals indicative of the high temperature starting mode designated by are respectively sent to the input end of the fuel injection drive means, thereby generating a signal for driving the fuel injection valve.

Figure 3 shows fuel 1! in high temperature starting mode! r! river+1i
This figure illustrates how the injection pulse width is controlled. As already mentioned, in the high temperature start mode, fuel injection is performed only for a preset period, but in the example shown in FIG.
A situation in which fuel injection is performed with a fixed pulse width only for a preset number of injections (N in the figure is 20, for example), and then the pulse width is rapidly narrowed down and one fuel injection ends after 20 injections. It shows. It is necessary to set the jetting period in this high-pitched starting mode to J: Unanaza in which paper is sufficiently removed.

The following modifications can be made to the embodiments of the present invention described above.

(1) In the above example,
The microcomputer included in ~14 may be not only a digital type but also an analog type.

(2) Instead of the intake air temperature used to determine the state of the engine at startup, the engine room temperature or the fuel pipe wall temperature may be used.

(3) High quality (the predetermined period of one-motion mode is a preset time (for example, 3 seconds) instead of the "number of fuel injections")
Even if it is defined by ":<, in which case the rotation center 9 in FIG. 4 is replaced by a suitable timer.

(Effects of the present invention) As mentioned above, the bag of the present invention is equipped with a means for determining the temperature of the cooling water and the intake air temperature used to determine whether the engine is in a high state when the engine is started, and when it is determined that the high quality state is present. By having a configuration that performs fuel 1 nozzle 1 in high temperature starting mode for a predetermined period and then shifts to fuel 1 injection in normal 11-movement mode after the predetermined period has elapsed, it has the following outstanding effects. can be played.

(1) Even if paper occurs in the fuel supply system when the engine is at high temperature, the
By injecting fuel in high temperature starting mode using a timed pulse, paper can be expelled at once, eliminating inconveniences such as paper lock, and it is possible to start the engine again in 1 hour. .

(2) Judgment for specifying fuel injection in high temperature start mode uses the detected values of cooling water temperature and intake air temperature, and when both are higher than a preset judgment reference value. Since fuel injection is performed only in the high temperature starting mode, it is possible to use a sensor that has been commonly used in the past, has a simple configuration, and is easy to install, and it is also possible to reliably determine the high temperature state. can.

(3) High) Fuel injection in crystal start mode is a preset injection! Since this is carried out only within a period defined by the J4 number of times or time, it is possible to control the required fuel increase at the time of starting the engine to an appropriate value with no excess or deficiency.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram for explaining the general configuration of a conventional device and a device of the present invention. FIG. 2 is a flowchart of the arithmetic processing performed by the microamp coater included in the control unit of the apparatus of the present invention in the configuration shown in FIG. FIG. 3 is a characteristic diagram illustrating the relationship between the number of times of nozzle 1 and the injection pulse width when the period during which fuel nozzle 1 is performed in the high temperature starting mode by the device of the present invention is defined by the number of injections. . FIG. 4 illustrates the configuration of the fuel injection control means included in the control units 1 to 1 of the device of the present invention in the configuration shown in FIG. 1, together with the elements shown in FIG. FIG. (Explanation of symbols) 7... Engine, 9... Rotation sensor-510...
Intake pipe, 11...1 No.1 trachea, 12...Air cleaner, 13...Fuel injection valve, 14...Conn 1~Roll unit 1~. 15... Fuel 1 pump, 16... Intake cloth sensor, 17... Cooling water temperature sensor, 18...
key switch. 1st...Fuel tank, 20...Fuel pressure regulating valve, 2
1...Fuel pipe, 22...Fuel return pipe, 2
3...Intake temperature sensor. Agent Akira Asamura

Claims (1)

[Scope of Claims] Comparison means for receiving a detection signal output from a sensor 1 which detects a parameter representing a starting state of an internal combustion engine having a fuel injection valve and comparing it with an H standard value of the parameter; a normal starting mode in which the output signal of the comparison means is input to the input terminal and a signal specifying the operation of the normal starting mode, which is a fuel injection mode that gives a fuel injection valve opening time according to the state at the time of starting the engine; An electronically controlled fuel injection device for an internal combustion engine, which includes a specifying means and a fuel injector driving means which receives an input signal including an output signal of the normal starting mode specifying means at an input end and outputs a signal for driving the fuel injector. a cooling water temperature sensor that detects a cooling water temperature when the internal combustion engine is started; an intake air temperature sensor that detects an intake air temperature when the internal combustion engine is started; and a cooling water temperature detection signal output from the cooling water temperature sensor. The value of the cooling water temperature detection signal is compared with a preset cooling water temperature reference value, and when the value of the cooling water temperature detection signal is less than or equal to the cooling water temperature reference value, a first output signal is output and the normal starting mode is started. When the cooling water temperature detection signal (1r1 is cold 1) exceeds the water temperature reference value, the second
a cooling water temperature comparison means that outputs an 81 force signal; and a cooling water temperature comparison means that inputs an intake temperature detection signal output from the intake temperature sensor, and outputs an intake temperature detection signal in response to a second output signal output from the cooling water temperature comparison means. The value is compared with a preset intake air temperature reference value, and if the value of the intake air temperature detection signal is less than the intake air temperature reference value, a first output signal is output and sent to the input end of the normal start mode designation means. However, when the value of the intake temperature detection signal is equal to or higher than the intake temperature reference value, intake temperature comparison means outputs a second output signal; outputting a first output signal specifying operation of a high temperature start mode which is a fuel injection mode using a long valve time pulse for a period of time and sending it to the input end of the fuel injection valve driving means, and after the predetermined period elapses; , a high temperature start mode designating means for outputting a second output signal and sending it to an input end of the normal start mode designating means.