JPS59147832A - Fuel injection volume control device of electronic- controlled fuel injection engine - Google Patents

Abstract

PURPOSE:To improve starting efficiency by controlling to stop a fuel injection for a fixed time after a starter is started to be operated to eliminate the smoking of an ignition plug and the like during the starter is in operation. CONSTITUTION:When starting an engine, it is judged whether a starter is in operation or not by an input signal from a starter switch 35. If it is in operation, it is judged whether a fixed time A (about 10-30sec) after an operation start of the starter passes or not. If not, a basic fuel injection volume gained based on an air flow meter 2 and a crank angle sensor 30 is corrected by an output of the cooling water temperature sensor 30 to control a fuel injection valve 41 in accordance with the corrected injection volume. While, the fuel injection from the fuel injection valve 41 is stopped when the fixed time A passes to prevent smoking of an ignition plug 14 and maintain a good starting condition for the next starter operating period.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling the fuel injection amount during a starter operation period in an electronically controlled fuel injection engine.

In such conventional control devices, the fuel injection amount per synchronous injection during the starter operation period is determined by the next parameter (cooling water temperature, etc.) at the time the starter starts operation.
Fuel injection was performed during the period of starter operation until the end of starter operation. Therefore, if the starter is not successfully started during the starter operation period, the amount of fuel in the combustion chamber will increase excessively, causing the spark plug to smolder, resulting in poor starting performance during the next starter operation period. There is.

An object of the present invention is to provide a fuel injection system for an electronically controlled fuel injection engine that can avoid fuel injection that causes spark plug smoldering and improve startability during the next starter operation period.
t control device.

In order to achieve this object, the fuel injection amount control device for an electronically controlled fuel injection engine of the present invention stops fuel injection after a predetermined period of time has elapsed from the start of starter operation during the starter operation period.

Therefore, even if the driver keeps the starter switch on for a long time, the total amount of fuel injected during the starter operation period is prevented from exceeding a predetermined upper limit, the spark plug is prevented from smoldering, and the next starter operation is prevented. Startability during the period is improved.

The present invention will be described in detail with reference to the drawings.

FIG. 1 is a general DIM configuration diagram of an electronically controlled engine to which the present invention is applied. Air is sent from the air cleaner 1 to the combustion chamber 8 of the engine body 7 via an intake passage 9 including an intake tank 4, intake ports 1 to 5, and an intake valve 6. The throttle valve 3 is linked to an accelerator pedal 10 in the driver's cab. The combustion chamber 8 is defined by a cylinder head 11, a cylinder block 12, and a piston 13, and the air-fuel mixture in the combustion chamber 8 is ignited by the ignition plaque 14 to be combusted, and then the exhaust valve 15, the exhaust boat 16,
It is discharged to the atmosphere through the exhaust branch pipe 17 and the exhaust pipe 18. The bypass passage 21 connects the upstream of the throttle valve 3 and the surge tank 4, and controls the flow cross-sectional area of the ISC valve (idle rotation speed control valve) 22 of the bypass passage 21 to maintain a constant engine rotation speed during idling. .

Detects the intake air temperature sensor and throttle position sensor 29
detects the opening degree of the throttle valve 3. The water temperature sensor 30 is attached to the cylinder block 12 to detect the cooling water temperature, that is, the engine temperature, the 02 sensor 31 is attached to the collecting part of the exhaust branch @17 and detects the oxygen concentration in the collecting part, and the crank angle sensor 32 11i of the power distributor 33 connected to the crankshaft (not shown) of the engine body 7
l+] Detects the crank angle of the crankshaft from the rotation of 34, and generates a pulse every time the crank angle changes by 30°,
The starter switch 35 generates an on signal when the starter is in operation, and an off signal when the starter is inactive. These sensors 2, 28.29.30. The output of '31.32.35 is sent to the electronic control unit 40. Fuel@shot 41 is provided near each intake boat 5 corresponding to each cylinder,
Fuel is injected toward the intake boat 5.

The electronic control unit 40 uses the input signals of each sensor to determine whether the fuel is burning or not. 5+,
The injection amount is calculated, and an electric pulse having a pulse width corresponding to the calculated fuel injection amount is sent to the fuel injection valve 41. Electronic controller 40 also controls ISC valve 22 and ignition system 46 . The secondary current of the ignition device 46 is sent to the spark plug J4 via the power distributor 33.

FIG. 2 is a block diagram of the inside of the electronic control device. C.P.
U56. ROM 57. RAM 58. Backup RAM 59. A/D with multiplexer (
analog/digital converter)60. and Ilo (input/output interface) 61 are connected to each other via a bus 62. The backup RAM 59 is connected to an auxiliary power source, and is supplied with a predetermined amount of power even when the ignition switch is opened and the engine is stopped so that the memory can be maintained. Air flow meter 2, intake temperature sensor 28
, water wetness sensor 30, and 02 sensor 31 [
] signal is sent to A/D 60. Outputs of the throttle position sensor 29, crank angle sensor 32, and starter switch 35 are sent to the l1061, and input signals are sent to the SC valve 22, fuel injection valve old, and ignition device 46 from the l1061.

FIG. 3 is a flowchart of a program implementing the present invention. This program is included in the main program. The final fuel injection amount is set at different steps during the starter operation period and the non-operation period (step 72 during the starter operation period).
~80, during the non-operation period of the starter, it is calculated in step 68), and in the starter operation period, it is calculated in step 7 until the predetermined time A has elapsed from the start of starter operation.
The final fuel injection amount hi at startup is calculated in steps 4 to 80, and after the predetermined time A has elapsed, the final fuel injection amount at startup is made zero in step 72, that is, the fuel injection from the fuel injection valve 4 is stopped. Explaining the flowchart in order, in step 66, it is determined whether the starter is operating or not based on the input signal from the starter switch 35, and if it is operating, the process proceeds to step 7o, and if it is not operating, the process proceeds to step 68. move on. In step 68, the final fuel injection amount at startup is calculated using a well-known program. Step 70
Then, the starter starts operating for a predetermined time A (A=IO~3
It is determined whether or not a predetermined time (0 seconds) has elapsed, and if the predetermined time A has not elapsed, the process proceeds to step 74, and if it has elapsed, the process proceeds to step 72. In step 72, combustion is performed.
Assign zero to u. Therefore, from this point on, the starter continues to operate (despite this, fuel*A, @injector 4
Synchronization from 1 E B M5 '44 is 11-. In step 74, the intake air flow rate Q and the engine rotational speed N are detected from the human power signals from the air flow meter 2 and the crank angle sensor 32. In step 76, the basic fuel consumption 11Il'1:Tp is calculated from the detected intake air flow PNtQ/fi-related rotational speed N. In step 78, the starting increase + 7j coefficient 1 (5 is subtracted as a function of the engine cooling water temperature, etc.). Figure 4 shows the relationship between the engine cooling water temperature and the starting increase) 1 [coefficient 1 (s). ing.

The starting time increase t1 is calculated by a coefficient I (s is a decreasing function of the cooling water temperature. In step 80, the final fuel injection amount Tau is changed to TpX
Substitute Ks. The synchronous fuel injection from the fuel injection valve 41 is performed in synchronization with a predetermined crank angle, and the fuel injection poison per 1 rotation of synchronous fuel injection is set to Tau.

FIG. 5 shows changes in the final fuel injection amount Tau and the amount of fuel in the combustion chamber during the period when the starter operation continues. The solid line shows the change in the case of the present invention, and the broken line shows the change in the case of the conventional device. In the conventional device, fuel injection continues from i=Q when the scooter starts operating until the starter stops operating, but in the present invention, fuel injection is stopped after t=A even though the starter is operating.

Therefore, in the case of the conventional device, the amount of fuel in the combustion chamber 8 continues to increase even after t2A, which causes the spark plaque 14 to smolder, making it difficult to start during the next starter operation period due to the restart operation. However, in the case of the present invention, the fuel 8@ in the combustion chamber 8 gradually decreases after t:A, and even after the fuel injection from the fuel injection valve 41 is stopped, the fuel adhering to the intake port 1-5 remains. The fuel in the combustion chamber 8 may flow into the combustion chamber 8, or the fuel in the combustion chamber 8 may
The fuel fi in the combustion chamber 8 may remain unexhausted.
) does not become zero immediately. ), smoldering of the spark plug 14 is avoided, and the startability is good during the period when the restart operation is performed and the starter is operated again.

FIG. 6 is a functional block diagram of the present invention. The timer 85 measures the elapsed time from when the starter switch 35 changes from OFF to ON, that is, from the start of starting the starter. During the starter operation period, the starting fuel injection amount calculation means 86 calculates a predetermined time A (predetermined time A
is detected by the input from timer 85. ), the intake air flow is a function of Q1, entrance rotation speed N1, cooling water temperature, etc., and the final fuel injection amount 'r a u is subtracted, and the fuel injection valve 41 is driven based on this T a u. death,
After the predetermined time A has elapsed, Tau is set to zero, and the fuel injection valve 41
Stops driving.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an electronic control engine to which the present invention is applied, FIG. 2 is a detailed block diagram of the electronic control device in FIG. 1, and FIG.
Figure 4 is a flowchart of a program that implements the present invention, Figure 4 is a graph showing the relationship between engine cooling water temperature and starting increase coefficient, and Figure 5 is a graph showing the final fuel injection amount from the start of starter operation during the starter operation period. FIG. 6, a graph showing changes in the amount of fuel in the combustion chamber, is a functional block diagram of the present invention. 35...Starter switch, 40...Electronic control unit, 41...Fuel injection valve, 85...Timer, 86...
・Starting twist'B @ shot amount calculation means. Patent applicant: Toyota Motor Corporation, i7 Representative patent attorney: Osamu Nakahira, -

Claims (1)

[Claims] A fuel injection J1 control device for an electronically controlled fuel injection engine, characterized in that fuel injection J1 is stopped after a predetermined period of time has elapsed from the start of starter operation during a starter operation period.