JPH01190968A - Starting control device for engine - Google Patents

Abstract

PURPOSE:To prevent knocking, when an engine is started, by providing a means which inhibits ignition for the predetermined time after a start of the engine begins, in case of the engine provided with a centrifugal ignition timing advancer. CONSTITUTION:First a power source is supplied to an ECU9 or the like. Next an engine cooling water temperature Tw is detected by a water temperature thermistor 16, when the temperature exceeds the predetermined water temperature generally in a condition that knocking is easily generated, starting of an engine is substantially inhibited by forcedly turning off the power source to an igniter 18 and stopping supply of an ignition signal to a spark plug 14 of an engine for the predetermined time. A starter switch is turned on, after the predetermined time the power source is supplied for the first time to the igniter 18, igniting the engine. When the ignition timing is controlled such as described, because no ignition is performed in an unstable region of rotation, essentially generating knocking, of a centrifugal ignition timing advancing device, no knocking is generated, and abnormal noise by the knocking in the time of starting can be prevented from being generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine starting control device.

(Prior Art) Generally, the best ignition timing for an engine is the moment when compression of the air-fuel mixture is completed and the piston reaches top dead center. but,
In reality, time lags due to factors such as electrical and mechanical delays and combustion delays cannot be avoided.

Therefore, the actual ignition timing is set to a crank angle slightly before the compression top dead center of the piston.

The ignition timing set in this way also varies depending on the engine speed and engine load.

For example, as the engine speed increases, the combustion speed of the engine naturally increases in proportion to it, but on the other hand, the tube fire delay (ignition waiting time) does not change even if the engine speed increases, so it only changes by the increase in engine speed. It becomes necessary to advance the ignition timing to advance the combustion timing, and as the engine load decreases, the amount of intake air decreases, and naturally the compression pressure and compression temperature within the engine combustion chamber also decrease. the result,
The ignition delay time becomes longer and the combustion speed becomes slower.

Therefore, it is necessary to advance the ignition timing.

For this reason, engine distributors generally include
The above-mentioned centrifugal ignition advance device advances the ignition timing in response to an increase in engine speed, and a vacuum ignition advance device advances the ignition timing in response to a decrease in intake negative pressure.

The centrifugal ignition advance device has a weight support pin on the governor plate (timing plate) that rotates together with the distributor shaft of the distributor, and uses this pin as a fulcrum to generate centrifugal force from the rotation at one end. is designed to open outward.

On the other hand, the distributor cam is fitted into the distributor shaft, and the cam driving pin of the governor weight is engaged with the engaging portion or window portion of the cam driving plate. Therefore, when one end of the governor weight opens due to centrifugal force, the distributor cam is moved and the distributor cam is slightly opened relative to the distributor shaft. In this way, the positional relationship between the engine cam shaft and the protrusion on the distributor cam becomes misaligned, which causes the piston position (
The speed of rotation becomes faster (the spread of the governor weight becomes larger) compared to the point opening time), achieving the purpose of advancing ignition (ignition timing advance).

Since the force that opposes the spread of the governor weight due to the centrifugal force is the governor spring, the retardation or retardation of the ignition advance angle ultimately depends on the force of this governor spring.
The weaker it is, the more advanced the advance angle becomes.
(See Publication No. 44277).

(Problems to be Solved by the Invention) However, in the centrifugal advance device using the governor weight as described above, there is a problem in that knocking occurs in the initial stage when the engine is started. This is because when the engine is started, the engine is in a cranking rotation state driven by the starter motor, but the initial stage of the cranking rotation (especially from the 1st rotation to the 5th rotation...
(see figure), because a large centrifugal force temporarily acts on the governor weight due to the driving force of the starter motor, the ignition timing becomes shorter than when stable rotation begins after that, as shown in figure 4. This is due to abnormal advice being given. That is, starter motors are generally designed to have a rating of about 30 seconds so as to have a large starting force especially at the time of starting, and suddenly apply a large torque to the engine to rotate it. Therefore, as a result, the centrifugal force becomes especially large at the beginning of the cranking, and the governor spring is thereby rapidly expanded, causing the above phenomenon.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and includes a centrifugal ignition advance device that controls the ignition advance according to the engine speed. The engine is provided with an ignition inhibiting means to inhibit ignition of the engine within a predetermined period of time after starting the engine.

(Function) According to the problem solving means of the present invention, a centrifugal ignition advance device is provided to control the ignition advance according to the engine speed, and furthermore, the ignition state of the engine is prohibited. Since the ignition inhibiting means is provided to prohibit ignition of the engine within a predetermined period of time after the engine starts, it is possible to prevent the engine from igniting in the rotationally unstable region of the centrifugal ignition advance device where nozzling would normally occur. The engine is not actually started until the engine is no longer ignited and the centrifugal ignition advance device enters a stable rotation range in which it can perform normal advance control.

(Example) First, FIGS. 2 and 3 show a starting control device for an automobile gasoline engine in which the present invention is applied, and FIG. FIG. 3, which is a schematic diagram of the system, is a flowchart showing the ignition timing control operation of the engine control unit in the control system at the time of starting the engine.

First, the outline of the control system according to the embodiment of the present invention will be explained with reference to FIG. 2, and then the control operation of the main parts will be explained.

In FIG. 2, reference numeral l is the engine body, and intake air is taken in from the outside via an air cleaner 30.
Thereafter, the air is supplied to the cylinder via an air flow meter 2 and a throttle chamber 3. Further, fuel is supplied from the fuel tank I2 to the engine side by the fuel pump 13, and is injected by the fuel injector 5.

The amount of air taken into the cylinder during running is controlled by a throttle valve 6 provided in the throttle chamber 3. The throttle valve 6 is operated in conjunction with the accelerator pedal.

Note that the throttle chamber 3 is provided with a bypass intake passage 7 that bypasses the throttle valve 6, and the bypass intake passage 7 includes an intake air amount adjusting means for controlling the engine speed during idling. A current controlled solenoid valve (IsC valve) 8 is provided.

Further, reference numeral 10 indicates an exhaust pipe provided with a three-way catalytic converter 11.

On the other hand, reference numeral 4 denotes a spark plug provided in the cylinder head of the engine body 1, and the spark plug I4
A predetermined ignition voltage is applied to the ignition valve through a distributor 17 and an igniter 18, each of which incorporates a centrifugal ignition advance device and a vacuum ignition advance device similar to the conventional ones for ignition advance control. The supply status of this ignition voltage (ON/OI?'F') and the time of supply (
The application timing (when ON), that is, the ON/OFF of the igniter 18 and the ignition timing timing when the igniter is ON, is determined by the ON/OFF signal supplied from the ECU 9 to the igniter 18 and the ignition timing control signal tgt when the ON signal is ON. be controlled. Also,
Reference numeral 19 is a knocking control sensor provided in the cylinder block portion of the engine main body I;
Voltage output V according to the intensity of engine knocking.

is output and input to the ECU 9. Further, reference numeral 20 denotes a boost pressure sensor 20 that detects the load amount of the engine, and detects an engine boost pressure B corresponding to the load amount of the engine and inputs it to the ECU 9.

The above ECU 9 is centered around a microcomputer (CI'U) which is, for example, an Iff section, and functionally includes a fuel injection amount control circuit, an ignition timing control circuit, a memory (ROM and rL).
AM), an interface (Ilo) circuit, etc. In addition to the above-mentioned detection signals, the interface circuit of the ECU 9 receives, for example, an IgON signal from the ignition key switch Igk shown in the figure, an engine starting signal (ECU trigger) caused by turning on the starter switch SWST, An engine rotation speed detection signal (crank angle signal) Ne from the engine rotation speed sensor (crank angle sensor) 15, a detection signal Tw of the engine cooling water temperature detected by the water temperature thermistor 16, and a detection signal Tw of the engine cooling water temperature detected by the throttle opening sensor 4, for example. Various detection signals necessary for normal engine control, such as a throttle opening detection signal TVO detected by the air flow meter 2 and an intake air amount detection signal Q detected by the air flow meter 2, are also input.

Although not shown, the drive shaft of a starter motor (starter motor) serving as an engine starting device is connected to the flywheel on the rotating shaft side of the engine main body l via a predetermined gear mechanism, and the drive shaft of a starter motor (starter motor) serving as an engine starting device is connected to the flywheel on the rotating shaft side of the engine main body l. When the switch 5Wst is turned on, the flywheel is rotated by the starter motor and driven to rotate.

Next, the operation of controlling the ignition state of the engine at the time of starting the engine by the engine control unit 9 will be explained in detail with reference to the flowchart of FIG. 3.

First, in step Sl, the ignition key switch Igk is turned on to supply power to the ECU 9 and the like of the engine. Next, proceeding to step S, the value of the engine cooling water temperature Tw detected by the water temperature thermistor 16 is determined as follows.
- Determine whether or not the water temperature is warm enough to exceed a predetermined temperature, for example, 50° C., in which knob king is likely to occur during boat fishing. If the result is YES, the process further proceeds to step S3, where it is determined whether or not the state of charge of the battery E is at least 90% charged to obtain sufficient operational reliability. When the engine is cold in the case of N0, in order to give priority to the engine starting performance, the process directly proceeds to step SIO, where the engine is ignited as usual and the engine is started immediately. In step S above, N
The same applies to the case o. If No in step S,
That is, when the battery voltage Va is low, the starting force of the starter motor is weak and abnormal advance is unlikely to occur.

On the other hand, if YES in step S3, first, in step S, the power to the engine side igniter 18 is turned off for a predetermined time tM after starting the engine (after turning on the starter switch SW8T), which will be described later. The timer TM for setting F is set to the predetermined set time LM, and then the process proceeds to step S.

In step S, the ignition key switch I
GK has one more starter switch 5Wst from IgoN.
It is determined that the engine has been turned to ON, that is, it is repeatedly determined whether or not an engine starting operation has been performed until the result is YES.

If the result is YES, the process proceeds to step S, where the timer TM is first turned on (triggered), and at the same time, at the same time, in step S7, the power to the igniter 18 is forcibly turned on (OI?). F and next step S, the above timer TM
When the set time [M has elapsed, the timer TtaMOFF
The supply of the ignition signal to the spark plug I4 of the engine is stopped until the time (La+milliseconds), and starting of the engine is substantially prohibited.

As shown in FIG. 4, for example, the set time tn is sufficient to overcome the unstable rotation region (from the first to fifth crank rotation) of the centrifugal advance device as described in the prior art section. It is set within a range that covers the engine speed and does not impair starting performance during startup. As a result, it is possible to reliably eliminate the knob king at the initial stage of starting the engine, which is caused by the drawbacks in the governor characteristics of the centrifugal advance device as described above, and the abnormal noise that occurs along with the knob king.

Then, when the set time Lm has passed and the timer TM is turned off, power is supplied for the first time to the igniter 18, which had been forcibly turned off until then, in step S8. ignite the engine.

(Effects of the Invention) As explained above, the engine start control device of the present invention is capable of inhibiting ignition in an engine equipped with a centrifugal ignition advance device that controls the ignition advance according to the engine speed. The invention is characterized in that means is provided to prohibit ignition of the engine within a predetermined period of time after the start of the engine.

That is, in the configuration of the present invention, a centrifugal ignition advance device is provided to control the ignition advance according to the rotational speed of the engine, and an ignition prohibition means for inhibiting the ignition state of the engine is further provided. Since ignition of the engine is prohibited within a predetermined period of time after the engine starts, the engine will not be ignited in the unstable rotation range of the centrifugal ignition advance device, where knob king would normally occur. The engine is actually started only when the centrifugal ignition advance device enters a stable rotation range in which it can perform normal advance control.

Therefore, according to the engine starting control device of the present invention, it is possible to reliably eliminate the occurrence of knocking during engine starting, as well as the generation of unpleasant engine noises caused by the knocking that occurs in the prior art.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to claims of the present invention, FIG. 2 is a control system diagram of an engine starting control device according to an embodiment of the present invention, and FIG. 3 is a flowchart showing the operation of the control device. FIG. 4 is a time chart showing control operation characteristics in the same embodiment. ! ... Engine body 2 ... Air flow meter 5, e, Φ, Fuel injector 6 ... Throttle valve 9 --- Engine control unit (ECU) 12 ... Fuel tank 14... Spark plug l5... Engine rotation 11ty7 (crank angle sensor) 17... Distributor 18... Igniter

Claims (1)

[Claims] 1. In an engine equipped with a centrifugal ignition advance device that controls the ignition advance according to the engine speed, an ignition prohibiting means is provided to prohibit ignition of the engine within a predetermined time after the start of the engine. An engine starting control device characterized in that: