JPH02230962A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To maintain good drivability by providing a forced ignition means outputting the ignition signal synchronously with the second angle signal in place of an ignition control means according to the judged result of a judging means. CONSTITUTION:An angle detecting means 1 outputting the angle signal at the preset crank angle position, a time measuring means 2 measuring the time between the first and second angle signals outputted in sequence from the angle detecting means 1, and an ignition control means 3 estimating the required rotation time from the first angle signal to the target ignition timing based on the measured time and outputting the ignition signal when this estimated time elapses are provided. A judging means 4 judging whether or not the target ignition timing is on the spark advance side from the second angle signal and whether or not the ignition signal is already outputted when the second angle signal is outputted and a forced ignition means 5 outputting the ignition signal synchronously with the second angle signal in place of the ignition control means 3 based on the judged result are provided. As a result, even during the operation in which the engine rotation is quickly increased, the preset spark advance of the ignition timing is obtained, and good drivability is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> This invention relates to an ignition timing control device for an internal combustion engine. (Prior Art) As one type of ignition timing control for an internal combustion engine, a crank angle sensor is provided that outputs a reference angle signal at every predetermined crank angle, and each time the reference angle signal is output, the time between the reference angle signals is determined. There is a system that measures the rotation time from the reference angle signal to the target ignition timing based on this measured time, and outputs an ignition signal when this estimated time has elapsed.

This type of control requires only a single detection section as a crank angle sensor, which has the advantage of simplifying the structure and reducing costs (Japanese Patent Laid-Open No. 62-2142
(See Publication No. 70, etc.).

(Problem to be Solved by the Invention) However, in this type of control, if the engine speed suddenly increases after estimating the rotation time required to reach the target ignition timing, the ignition timing will be delayed. . Therefore, during acceleration, etc., the ignition timing is delayed, which adversely affects drivability.

This invention aims to solve these problems. (Means for Solving the Problems) As shown in FIG. 1, the present invention includes an angle detection means 1 that outputs an angle signal at a predetermined crank angle position, and angle detection means 1 that outputs an angle signal in order from the angle detection stage 1. 1. A time measuring means 2 that measures the time between the second angle signals, and based on this measured time, estimates the required rotation time from the first angle signal to the target ignition timing, and fires the ignition when this estimated time has elapsed. ignition control means 3 that outputs a signal, and determines whether the target ignition timing is on the advanced side of the second angle signal and whether the ignition signal has already been output when the second angle signal is output. and forced ignition means 5 for forcibly outputting an ignition signal in synchronization with the second angle signal in place of the ignition control means 3 based on the result of this determination. (Function) That is, when the target ignition timing is on the advance side of the second angle signal and the ignition signal has not been output by the time the second angle signal is output, the second angle signal Since the ignition signal is forcibly output in synchronization, if the engine speed suddenly increases after estimating the rotation time required to reach the target ignition timing, it is possible to prevent the ignition timing from being delayed beyond the timing of the second angle signal. ．． (Embodiment) FIG. 2 is a block diagram showing an embodiment of the present invention.
is a crank angle sensor that detects the engine crank angle,
12 is an air flow sensor that detects the intake air amount of the engine; 13 is a water temperature sensor that detects the engine cooling water temperature;
14 is a control unit, 15 is an ignition coil, 16
is a spark plug. In the case of a 4-cylinder engine, the crank angle sensor 11 is, for example, 80" before the piston top dead center (TDC) (806BT
The control unit 14 outputs a first angle signal at 5 degrees before (5 degrees BTDC) and a second angle signal at 5 degrees before (5 degrees BTDC). It consists of a beater. Next, the details of the control of the ignition timing by the control unit 14 will be explained based on the flowcharts of FIGS. 3 and 4 and the timing chart of FIG. 5.

As shown in FIG. 3, when the first angle signal is input from the crank angle sensor 11, the timer starts counting in S101, and the engine rotational speed N and target ignition timing ADV are set in S102. Target ignition timing ADV. Time required to TADV. is calculated, and FLG=1 is set in S103. Here, the engine rotational speed N is determined by measuring the elapsed time from the previous second angle signal when the first angle signal is input, and is obtained from this measurement time. In this case, N is the previous measurement time and the current N at the target ignition time ADVO may be determined by correcting it by comparing it with the measured time. Also, target ignition timing ADV. are the engine speed N, the amount of intake air from the air flow sensor 12, and the water temperature sensor 1.
For example, it is calculated every engine revolution according to the cooling water temperature etc. from 3.

Then, in S104, the timer determines the required time TADV. After counting, it is determined whether FLG=0 or not in S105, and if FLG=1, an ignition signal is output to the ignition coil 15 in S106 and S107, and FLG=O is set. In contrast, the timer indicates the required time TADV. If the second angle signal is input from the crank angle sensor 11 before counting is finished, FLG is inputted in S201 as shown in FIG.
=O or not, the target ignition timing ADV.
is on the advanced side of the second angle signal timing ADV2, and if FLG=1, ADV0>A
If D V zte exists, an ignition signal is output to the ignition coil 15 in S203 and S204, and FLG=O is set. With this configuration, the target ignition timing ADV. is on the advanced side than the second angle signal (S202), and when the second angle signal is output, the target ignition timing ADV. Time required to TADV. has passed (S104)
, an ignition signal is output at the point in time (S106). That is, when there is no delay with respect to the engine rotation speed N,
The ignition timing is determined by the target ignition timing ADV. as shown in Figure 5. It is controlled by. On the other hand, the target ignition timing ADV. is on the advanced side of the second angle signal (S202), but when the second angle signal is output, the target ignition timing ADV. If the required time TADVO has not elapsed (S104), the second
An ignition signal is output at the time when the angle signal is output (S20
1, 8203) In other words, if the engine speed N suddenly increases while counting the required time TADVo, in the conventional example, the ignition timing is delayed and reaches after the piston top dead center, as shown in Fig. 6, for example, but in this case In the embodiment, in this case, the ignition timing is not delayed beyond the second angle signal, and is at a predetermined timing before the piston top dead center. Therefore, good drivability can be maintained even during acceleration. Note that the target ignition timing ADV. is on the retarded side than the second angle signal (S202), the ignition signal is output when the required time TADVO has elapsed (S104, 106)
．． In this case, the engine speed is reduced to a low speed and the ignition timing is not delayed, so the ignition timing is changed for the required time TADV.
Target ignition timing ADV due to the passage of time. It is controlled by. (Effects of the Invention) As described above, the present invention provides an angle detection means that outputs an angle signal at a predetermined crank angle position, and a time interval between the first and second angle signals sequentially output from the angle detection means. and an ignition control means that estimates the required rotation time from the first angle signal to the target ignition timing based on the measured time and outputs an ignition signal when the estimated time elapses. , determining means for determining whether the target ignition timing is on the advanced side of the second angle signal and whether or not the ignition signal has already been output when the second angle signal is output; and the ignition control based on the determination result. Since a forced ignition means for forcibly outputting an ignition signal in synchronization with the second angle signal is provided in place of the means, it is possible to obtain a predetermined advance of the ignition timing even when the engine rotation is rapidly increasing. It is possible to maintain good drivability.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention, Figs. 3 and 4 are flow charts showing control contents, and Figs. 5 and 6 are timing charts thereof. be. DESCRIPTION OF SYMBOLS 11... Crank angle sensor, 12... Air flow sensor, 13... Water temperature sensor, 14... Control unit, 15... Ignition coil, 16... Spark plug Figure 1 Patent applicant Nissan Motor Co., Ltd. Co., Ltd.Figure 2Figure 3Figure 5Figure 6

Claims (1)

[Claims] An angle detection means for outputting an angle signal at a predetermined crank angle position, a time measurement means for measuring the time between the first and second angle signals sequentially output from the angle detection means, and a time measurement means for measuring the time between the first and second angle signals sequentially output from the angle detection means. and ignition control means for estimating the required rotation time from the first angle signal to the target ignition timing and outputting an ignition signal when the estimated time elapses, and the target ignition timing is further advanced than the second angle signal. determining means for determining whether the ignition signal is already output at the time of outputting the second angle signal; and determining means for determining whether the ignition signal is already output when the second angle signal is output; 1. An ignition timing control device for an internal combustion engine, comprising forced ignition means for automatically outputting an ignition signal.