JPS6350668A - Ignition timing control device for engine - Google Patents

Abstract

PURPOSE:To prevent over retardation to ensure appropriate ignition thereby to enhance the startability of a vehicle, by judging whether the clutch is engaged or not during the vehicle starting, in accordance with the vehicle speed and a neutral signal so that the control of ignition timing is delayed by a predetermined time. CONSTITUTION:A ignition timing map having engine rotational speeds detected by a crank angle sensor 5 and intake air amounts detected by a hot wire type air-flowmeter 1 as parameters is stored in a ROM 24 in a control device 20. When the control device 20 judges that the vehicle speed is substantially 0 km/hr. in accordance with a signal from a vehicle speed sensor 6 and a neutral switch 7 is turned off, it determines that the vehicle is in such a clutch engaging condition that the vehicle is to be started. Further, the control of ignition timing is delayed for a clutch engaging period which is determined as the time until the vehicle speed reaches a predetermined value. With this arrangement it is possible to prevent over retardation during the vehicle starting due to that the intake air amount is consumed for charging the capacity of the intake-air system.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an ignition timing control device in a lightning control fuel 111f injection system for an engine with hot wire airflow make.

[Conventional technology]

Currently, the hot wire air flow meter type electronically controlled fuel injection system calculates the basic fuel injection amount based on the intake air pressure and engine speed, and uses the engine speed and intake air amount as a grid as shown in Figure 4. As shown, the corresponding optimum ignition timing is stored in advance in the form of a map, the ignition timing corresponding to the operating condition is read from the map, and an ignition command is given to the ignition system. There are movable vane type, Karman vortex type, turbine type, and hot wire type for measuring the amount of intake air, but these methods have good response, simple structure, and are capable of measuring quality and flow. Due to these reasons, there is a tendency for the hot wire method to be adopted. In addition, in order to obtain stable ignition timing characteristics in the starting rotation range where there are rotational fluctuations, there is, for example, a system that delays the ignition timing for a certain period of time, as disclosed in Japanese Patent Application Laid-Open No. 56-t13051. Sometimes the ignition is delayed to alleviate torque fluctuations, but for example,
There is a publication No. 56-98569.

[Problems to be solved by the invention]

Incidentally, the hot wire type air flow meter responds extremely well to changes in the intake air flow rate, but on the other hand, for example, when the clutch is engaged at the time of starting, even though the throttle valve 71 is only half open, As shown in Figure 5, the response of the air flow meter is so good that it is mistaken for an instantaneous increase in the amount of intake air at clutch engagement.This is detected as is, and the ignition timing control 2p device There is a problem in that if the ignition timing is output with the valve fully open, the engine will overretard, resulting in a decrease in output torque and deterioration of starting performance. In addition, if the intake system has a volume such as a chamber, the intake air m is used to fill that volume, so the air required by the engine is less than the actual throttle opening. There is a tendency. The present invention was made in order to solve such problems, and in the ignition timing control in the hot wire airflow meter type electronically controlled fuel injection system, it prevents overretardation at the time of clap meet at the time of starting, and improves starting performance. 1 engine ignition timing control device designed to improve
The purpose is to serve H1.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a hot wire air flow meter type electronic till fuel injection system, in which the ignition timing control device is equipped with an ignition timing map that uses engine speed and intake air amount as a grid, and the vehicle speed is controlled by the ignition timing map. A means for determining whether the speed is within a predetermined heavy speed, and a means for determining whether a neutral switch for detecting the gear position is OFF. A delay means is provided which determines whether the clutch is engaged at the start 1F, - and delays the RF3 control at the time of ignition by a predetermined period of time when the clutch engagement is determined.

[For production]

Based on the above configuration, when the vehicle speed determining means determines substantially 0 klIl/Hr based on the signal from the vehicle speed sensor and the neutral switch determining means determines the OFF state of the neutral switch, the delay means determines whether the vehicle is in a clutch engagement state about to start. It is determined that the period from now until the vehicle speed reaches a predetermined vehicle speed is a clutch engagement period, and during that period, ignition timing control is delayed to prevent over-retardation of the start-up based on the 8-slip of the intake system.

【Example】

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3. Figure 1 is a block diagram showing the general configuration of a hot wire airflow meter type electronically controlled fuel injection system, and Figure 2 is a program diagram showing its control program.

[Figure 21 and Figure 3 are flowcharts showing the operation of the present Komei ignition timing control device. In the figure, 1 is a hot wire type air flow make,
Outputs a signal according to the intake air flow rate. 2 is a water temperature sensor that detects the engine coolant temperature, 3 is O
t sensor, 4 is a throttle opening sensor, 5 is a crank angle sensor, 6 is a vehicle speed sensor, and 7 is a neutral switch, which is turned on when the gear is in the neutral position. , 8 is an injector, 9 is an ignition device including a nozzle repeater and an ignition coil, 10 is a spark plug, 20 is a control device consisting of a microcomputer, 21 is an A/D converter, 22 is an input interface, 23 is a CPU, 24 25 is a RAM, and 26 is an output interface. In addition, in FIG. 2 showing the control program, 3
0 is an intake air amount calculation means 31 that converts the signal from the pot wire air flow meter 1 into intake air ff1Qa;
32 is a basic fuel injection □□□n output that calculates the basic fuel injection amount based on the intake air ff1Qa and the engine speed Ne. Means 33 is a correction means, which adjusts the calculated basic fuel injection amount to the water temperature increase prediction based on the signal 9Tw of the water temperature sensor 2, and the throttle opening sensor 4.
The fuel injection pulse signal is outputted to the injector 8 after performing corrections such as acceleration increase based on the signal θ and feedback correction based on the signal from the 02 sensor 3. 34 is 1v]m when ignited
The output means uses the intake air ffj Q a and the engine rotational speed Ne signal as address signals, and stores the data in the ROM2 in advance.
The ignition timing map stored in the ignition timing map 4 is searched, the corresponding ignition timing is read out, the obtained ignition timing signal is output to the ignition device 9, and the spark plug 10 is activated. Next, 36 to 38 are program means according to the present invention, 36 is a determination means for determining whether or not the neutral switch 7 is OFF, and 37 is a determination means when the vehicle speed signal from the vehicle speed sensor 6 is within a predetermined vehicle speed, for example 0 to A vehicle speed determining means 38 is a delay means for determining whether or not the vehicle speed is within the range of 2 km, /11, and when the determinations of the re-determining means 36 and 37 are both YES and the clutch engagement for starting is determined, For example, the clutch engagement period is until the vehicle speed reaches 2 km/h, and the ignition time tg1n output means 34 is limited to this period.
A signal that adds a delay time to the ignition timing extraction time is output. Next, the operation of the present invention will be explained with reference to the flowchart shown in FIG. In executing the ignition timing calculation routine, first, the intake air amount Q calculated by the intake air amount calculation means 30 is
a and the engine speed Ne determined by the engine speed output means 31 are read (step 5100), and then the vehicle speed determination means 37 and the neutral switch are turned off.
Read the determination result from the determination means 36 (step 31
01). If the vehicle speed is between ○ and 2 km/h (step 8102) and the neutral switch is in the ON state (step 8103), it is determined that the vehicle is in an idling state (step 3105), and the delay means 38
is in the OFF state, and the ignition timing calculation means 34 reads the corresponding ignition timing from the ignition timing map 35 on-time based on the intake air ff1Qa and the engine speed Ne (Step 8107), and the ignition timing signal is set to ignition '4A. Send to station 9. In order to start the vehicle from this idle link state, the clutch is turned OFF and the gear is shifted from the neutral position. Since the neutral switch is turned OFF (step 5103), step (S
In step 104), the delay means 38 is turned ON, and the period until the vehicle speed reaches Okm/h/Jl, etc. 2 +n/h is set as a clutch engagement period, and the signal is given to the ignition timing calculation means 34, and the delay means 38 is limited to this period. The map search is delayed so that a delay time is added to the ignition timing calculation time (step 8106). At this time, the vehicle starts, so the throttle opening changes from fully open to half open, and for the reason mentioned above, the hot wire air flow meter 1, which has good responsiveness,
outputs a signal that is approximately the same as when the throttle is fully open, but a delay time is added during this time as a clutch contact period, so it does not respond to transient large currents.
To prevent over-retardation by blocking the output of ignition timing based on throttle noise. Next, by starting! When the n speed becomes 2klIl/h or more, in step 5102), the delay means 38 is set to 0FFL. <Step 8105), the ignition timing calculation means 34 reads the normal ignition timing on time.Step $107
'), sends the ignition timing signal to the ignition device 9,
Ignition is performed (step 3108). [Effects of the Invention] As explained above, according to the present invention, the clutch engagement at the time of starting is determined based on the vehicle speed and the neutral signal, and the ignition timing control is delayed for a predetermined time.
It is possible to prevent a sudden change in the ignition timing at the time of starting, that is, overretard, and to ensure proper ignition at the time of starting, thereby improving starting performance. In addition, since the delay time is applied only when starting, the excellent responsiveness of the hot wire air flow meter can be reflected in the ignition timing signal under other operating conditions, thereby suppressing the occurrence of non-king. This has the effect that it also becomes possible.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention,
FIG. 1 is a block diagram showing the configuration of a hot wire, air flow meter type electronically controlled fuel injection system, FIG. 2 is a block diagram showing the configuration of its control program, and FIG. 3 is a flow chart showing the operation of the present invention. FIG. 4 shows an ignition timing map, and FIG. 5 shows a transient change in intake air amount during clutch engagement. DESCRIPTION OF SYMBOLS 1...Hot wire type air flow meter, 5...Crank angle sensor, 6...Vehicle speed sensor, 7...Neutral switch, 9...Ignition equipment, 20...Control device, 34...・Means for numbing during ignition, 35...Ignition timing map, 36...Neutral switch OFF￥IJ
determining means, 37...vehicle speed determining means, 38...delay means. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Jundo Nobu Kobashi Patent Attorney Susumu Murai [D Yo30

Claims (1)

[Claims] In a hot wire airflow meter type electronically controlled fuel injection system, the ignition timing control device is provided with an ignition timing map using a grid of engine speed and intake air amount, and means for determining whether the vehicle speed is within a predetermined vehicle speed. and a means for determining whether or not a neutral switch that detects the gear position is OFF, and determining clutch engagement at the time of starting based on the determinations of both of the above means, and controlling the ignition timing for a predetermined time when clutch engagement is determined. An ignition timing control device for an engine, comprising a delay means for delaying the ignition timing of the engine.