JPH0710059Y2 - Engine ignition timing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine ignition timing control device.

(Prior Art) In recent engines, many electronically control ignition timing. In this configuration, at least when determining the basic ignition timing, the basic ignition timing corresponding to the operating state of the engine is stored in advance, and the basic ignition timing corresponding to the current operating state is read from this storage means. Be done. As the operating state of the engine as a parameter for determining the basic ignition timing, the engine speed and the engine load are generally used. The amount of intake air is often used as the engine load (see Japanese Patent Laid-Open No. 62-147049).

On the other hand, a sufficient feeling of deceleration is required during deceleration, and from this point of view, it is desirable to retard the ignition timing as compared with during normal traveling. Therefore, conventionally, the ignition timing for normal traveling, which is retarded by a predetermined amount, is used as the ignition timing for deceleration.

(Problems to be solved by the invention) However, in the case where the ignition timing at the time of deceleration is obtained by retarding the ignition timing at the time of deceleration as in the above-described conventional case, the ignition timing varies. This often causes problems such as deterioration of drivability during deceleration and insufficient feeling of deceleration. Such a problem is likely to occur particularly at the initial stage of deceleration, and also when the flap type is used as the intake air amount detecting means.

Upon pursuing the cause of such a problem, it was found that the detected value of the intake air amount varies as a parameter for determining the ignition timing. That is, it was found that when the normal traveling is changed to the deceleration, the intake air amount is sharply reduced, and at this time, hunting is likely to occur in the detected value of the intake air amount.

Therefore, the object of the present invention is to determine the basic ignition timing for normal traveling based on the engine speed and the intake air amount. An object of the present invention is to provide an engine ignition timing control device capable of obtaining a feeling of deceleration.

(Means and Actions for Solving Problems) In order to achieve the above object, the present invention has the following configuration. That is, as shown in a block diagram in FIG. 5, an intake air amount detecting means for detecting an intake air amount, a rotation speed detecting means for detecting an engine speed, a deceleration detecting means for detecting a deceleration, and the rotation speed. First ignition timing determination means for determining a basic ignition timing for normal traveling based on the engine speed detected by the number detection means and the intake air amount detected by the intake air amount detection means, and the deceleration detection When the deceleration is detected by the means, the second ignition timing for deciding the basic ignition timing for deceleration based on only the engine speed detected by the engine speed detection means, prior to the first ignition timing determination means. The determining means is provided.

As described above, in the present invention, during normal driving,
The basic ignition timing can be determined by using the engine speed and the intake air amount as parameters, and the basic ignition timing during normal traveling can be optimally set as in the conventional case.

On the other hand, at the time of deceleration, the basic ignition timing for deceleration is determined by using only the engine speed as a parameter without using the intake air amount that is likely to cause fluctuations in the detected value, so that good drivability of the engine is ensured and It is possible to obtain a sufficient sense of deceleration. During deceleration, since the throttle valve is uniformly set to be fully closed or close to fully closed, there is practically no problem even if the intake air amount is not used as a parameter.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an Otto type engine body of a 4-cycle reciprocating type. The engine body 1 is fitted into a cylinder block 2, a cylinder head 3 and a cylinder 2a of the cylinder block 2 as is known. A combustion chamber 5 is defined by the inserted piston 4. This combustion chamber 5
A spark plug 6 is arranged in the air intake port, and an intake port 7 and an exhaust port 8 are opened.
The intake valve 9 or the exhaust valve 10 opens and closes at a known timing in synchronization with the engine output shaft.

An air cleaner 22, an air flow meter 24 for detecting the amount of intake air, a throttle valve 25, a surge tank 26, and a fuel injection valve 27 are sequentially arranged in the intake passage 21 connected to the intake port 7 from the upstream side to the downstream side. ing. In the exhaust passage 28 connected to the exhaust port 8, an air-fuel ratio sensor 29 and a three-way catalyst 30 as an exhaust gas purifying device are sequentially arranged from the upstream side to the downstream side.

In FIG. 1, reference numeral 31 is a control unit constituted by a microcomputer. The control unit 31 receives signals from switches or sensors 32, 33, 34 in addition to the intake air amount signals from the sensor air flow meters 24. It is supposed to be entered. The switch 32 is an idle switch that is turned on when the opening degree of the throttle valve 25 becomes close to or less than the fully closed state, the sensor 33 detects the engine cooling water temperature, and the sensor 34 is attached to the distributor 36. The crank angle, that is, the engine speed is detected. Further, the control unit 31 outputs an ignition timing signal to the igniter 37. That is, a predetermined ignition timing signal is sent to the igniter 37 by the control unit 31.
Is output from the battery 35, the primary current from the battery 35 to the ignition coil 38 is cut off to generate a high voltage on the secondary side thereof, and the high voltage on the secondary side is supplied to the ignition plug 6 via the distributor 36. Will be done.

The control unit 31 basically consists of CPU ROM, RAM, CLO.
A CK and the like are provided, but since these are known configurations when a microcomputer is used, description thereof will be omitted.
Of course, the map for determining the basic ignition timing, which will be described later, is stored in the ROM.

The control unit 31 stores two types of basic ignition timings, that is, a basic ignition timing for normal traveling and a basic ignition timing for deceleration. As shown in FIG. 2, the basic ignition timing for normal traveling is set with the engine speed and the intake air amount as parameters. Further, the basic ignition timing for deceleration is set with only the engine speed as a parameter, as shown in FIG. In FIG. 3, the vertical axis represents the intake air amount, but the actual stored value is not related to the size of the intake air amount. Of course, during normal running, the basic ignition timing is determined based on the map shown in FIG. 2, and during deceleration the basic ignition timing is determined based on the map shown in FIG. 3 instead of the map shown in FIG. The water temperature correction of the ignition timing and the like are commonly performed during normal traveling and during deceleration.

The control contents described above are shown in the flowchart of FIG. 4, which will be described below. In the following description, P indicates a step.

First, at P1, the signals from the R sensors 24, 32, 33, 34 are read, and at P2, the water temperature correction value θ of the ignition timing is read.
W is determined.

After P2, in P3, it is determined whether or not the idle switch 32 is turned on. If YES in this determination, it is determined in P4 whether or not the current engine speed N is equal to or lower than a predetermined engine speed N ₁ which is set in advance. If YES in the determination of P4, the vehicle is decelerating. At this time, in P5, the current engine speed N is collated with the map shown in FIG. 3 to determine the basic ignition timing θD for deceleration. It Thereafter, in P6, the final ignition timing θ is determined by adding the correction value θW determined in P2 to the basic ignition timing θD determined in P5. Then, at P7, the final ignition timing θ is output to the igniter 37.

When NO is determined in either P3 or P4, it means that the vehicle is traveling normally. At this time, the routine proceeds to P8, where the current engine speed N and the intake air amount TP are collated with the map shown in FIG. 2 to determine the basic ignition timing θB. After this, the correction value θW at P2 is added to the basic ignition timing θB to obtain the final ignition timing θ, and then the routine proceeds to P7.

(Effects of the Invention) As is apparent from the above description, the present invention optimizes the basic ignition timing for normal traveling using the engine speed and the intake air amount as parameters, while varying the basic ignition timing during deceleration. Therefore, it is possible to secure good drivability of the engine at the time of deceleration and obtain a sufficient deceleration feeling.

[Brief description of drawings]

FIG. 1 is an overall system diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing a map in which the basic ignition timing for normal traveling is stored. FIG. 3 is a diagram showing a map storing the basic ignition timing for deceleration. FIG. 4 is a flowchart showing a control example of the present invention. FIG. 5 is a block diagram showing the configuration of the present invention. 1: Engine body 6: Spark plug 24: Air flow meter (intake air amount detection means) 31: Control unit 34: Sensor (engine speed)

Claims (1)

[Scope of utility model registration request] 1. An intake air amount detection means for detecting an intake air amount, a rotation speed detection means for detecting an engine rotation speed, a deceleration detection means for detecting deceleration, and an engine rotation detected by the rotation speed detection means. A first ignition timing determining means for determining a basic ignition timing for normal traveling based on the number and the intake air amount detected by the intake air amount detecting means; and when deceleration is detected by the deceleration detecting means, Second ignition timing determining means for determining the basic ignition timing for deceleration based on only the engine speed detected by the rotation speed detecting means, prior to the first ignition timing determining means. An ignition timing control device for an engine.