JPH0460175A - Engine ignition timing control device - Google Patents

Abstract

PURPOSE:To improve maintainability relating to discovery or the like of failure while contriving reduction of a cost of a device total unit by providing such constitution as covering start time advance timing controlling and overheat detecting temperature sensors by a single temperature sensor. CONSTITUTION:A microcomputer circuit 52, serving as a main control part which restricts increase of an engine speed while driving a buzzer B1 in the case of detecting a heated condition of an engine by a temperature sensor SE1 mounted onto a cylinder head 100, is provided. Further, a start time ignition timing control function, which performs advance timing control at engine start time based on engine temperature information fed from this temperature sensor SE1 while always inputting an output signal from the temperature sensor SE1 before starting the engine, is provided. Stabilization of detecting sensitivity is contrived while simplifying circuit constitution by thus forming a start time advance timing controlling lamp sensor and an overheat detecting sensor in common.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine ignition timing control device, and in particular to an engine ignition timing control device configured to change the ignition timing at the time of starting according to the temperature level of the engine. Regarding a control device.

[Conventional technology]

Recent marine engines, especially outboard motors, have adopted a start-advance system that automatically advances the ignition timing beyond the maximum retard position in order to improve startability.

Furthermore, this system does not simply advance the ignition angle under constant conditions, but also incorporates a function of controlling the advance time or ignition timing itself depending on the engine temperature. On the other hand, if the engine overheats due to poor cooling water pumping, etc., a temperature sensor is generally equipped with an overheat warning function that detects the rising engine temperature and alerts the driver by sounding a buzzer, lighting a lamp, etc. It is being

A typical advance mechanism for outboard motors is achieved by mechanically sliding a magneto stator in conjunction with the throttle opening. However, recently, this method has been replaced by a method in which a throttle sensor is attached to the throttle shaft of the carburetor, and the opening signal from this sensor is input to the ignition circuit to obtain the ignition timing according to the throttle opening. .

In addition, in the case of outboard motors, extremely slow and smooth rotation, known as trolling rotation, is required, so the ignition timing when the throttle is fully closed is set to a much later date after top dead center in order to lower the explosion pressure. This is often the case. However, since the combustion speed is slow at startup, if the ignition timing remains delayed, starting performance is poor, and it is necessary to advance the ignition timing to nearly 10' before top dead center.

Therefore, the above-mentioned throttle sensor advance type often has a function that automatically advances the angle at the time of starting. are being changed in stages.

On the other hand, the above-mentioned lamp sensor for overheat warning is
It is provided separately and is also installed near the cylinder head.

[Problem B to be solved by the invention] However, in the above conventional example, the temperature sensor for starting advance angle control and the temperature sensor for overheat warning are naturally provided independently and separately. . This complicates the mounting layout, and the thermal conductivity changes depending on the location, making testing of operating temperature settings complicated. Furthermore, since two sensors are required, the cost is high. Furthermore, since there are two signal input systems, the circuit configuration is complicated and the cost is also high.

[Object of the Invention] The object of the present invention is to improve the disadvantages of the conventional example, and in particular to simplify the overall structure by consolidating the temperature sensor and its circuit configuration into one system, which reduces performance. To provide an engine ignition timing control device which allows the entire device to be obtained at a low cost.

[Means to solve the problem]

In the present invention, a temperature sensor installed in or near the cylinder head, an alarm means for issuing an alarm to the outside when the temperature sensor detects an overheating state of the engine, and an output signal from the temperature sensor are input. The engine also includes a main control section that drives the warning means and regulates an increase in engine speed as necessary. Then, the main control unit further
It is equipped with a starting ignition timing control function that constantly inputs the output signal from the temperature sensor before the engine starts, and controls the advance angle at the time of engine starting based on the engine temperature information sent from this temperature sensor. It has this configuration. This aims to achieve the above-mentioned purpose.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 6.

The embodiment shown in FIGS. 1 to 6 uses a temperature sensor SE1 installed on the cylinder head 100, and a warning means for issuing a warning to the outside when the temperature sensor SEI detects the heating state of the engine. Buzzer B1 and
It is provided with a microcomputer circuit 52 as a main control section which inputs an output signal from the temperature sensor SEI and drives a buzzer B1 as necessary to regulate an increase in engine speed. This microcomputer circuit 52 further includes a temperature sensor SEI.
It has a starting ignition timing control function that constantly inputs the output signal from before the engine starts, and performs advance angle control at the time of engine starting based on the engine temperature information sent from the temperature sensor SE1.

This will be explained in further detail. FIG. 1 shows the overall circuit configuration of an ignition device including the present invention. In this embodiment, a magneto serving as the power supply part of the ignition system, a unit configuring a circuit for receiving power and signals from the magneto and performing various controls, and various sensors connected to this unit, It consists of indicator lights, buzzers, etc.

As shown in FIG. 2, the magneto is constructed such that a rotor 11 with a magnet 1O mounted on the inside and a ring gear 9 mounted on the outside is attached to an engine crankshaft (not shown). Further, a trigger ball 8 is attached to the outside of the rotor 11, and a pulsar coil 2 is placed opposite the trigger ball 8.
~5 are arranged at 90° intervals. Furthermore, the rotor 11
A condenser charging coil 1 and a battery charging coil 7 are arranged on the inside of the ring gear 9, and a gear count coil 6 is arranged on the outside of the ring gear 9.

Next, as shown in FIG. 1, the unit uses the battery as a power source, and receives the output of the gear count coil 6, the throttle opening signal from the throttle sensor 12, the engine temperature signal from the engine temperature sensor SEI, and the oil level sensor. Input signals from SE2, oil level sensor SE3, etc. This unit section outputs a control signal to the pulser coils 2 to 5 through a noise filter 50, a microcomputer circuit 52 that outputs a control signal to the trigger output buffer, and an ignition timing control signal to the ignition circuit section based on the output of the microcomputer circuit 52. It is composed of a trigger output buffer 53, a switch circuit 54 that cuts off the pulser coil output, a waveform shaping circuit 51 that shapes the pulser coil waveform, and an interface circuit 60 that exchanges signals between the microcomputer and various sensors. . Reference numeral 61 indicates an A/D converter, and reference numeral 62 indicates an LED lighting circuit for displaying rotation speed regulation.

The ignition circuit section uses capacitors CI and C2 to store the power generated in the capacitor charging coil 1, and the power stored in the capacitors CI and C2 to the ignition coil by signals from the pulser coils 2 to 5 via the noise filter 50. Thyristor 5CRI to 5CR4 for supplying
It is composed of.

Next, the overall operation will be explained.

When the engine is started by a starter motor (not shown), a binion gear (not shown) meshes with a ring gear, thereby first rotating the rotor 11.

When the rotor 11 rotates, an electromotive force is generated in the capacitor charging coil 1. FIG. 4 shows the output waveform in this case.

Then, a predetermined amount of power is stored in the capacitor C1 by the positive (±) side output of this capacitor charging coil 1, and the negative (−) side output is stored in the capacitor C1.
) side output, a predetermined amount of power is stored in the capacitor C2. After the capacitor C1 is charged, when the end face of the trigger ball 8 and the pulser coil 2 face each other, a negative output of the pulser coil 2 is generated, and current flows to the microcomputer circuit 52. In this case, under the control of the microcomputer circuit 52, this signal is not output from the trigger output buffer onward for several seconds after starting. When the rotor 11 further rotates and the other end surface of the trigger ball 8 and the pulser coil 2 face each other, an output is generated on the positive side of the output waveform of the pulser coil 2. Due to this output, current flows from "pulsar coil 2 → noise filter → diode D3 → gate of thyristor 5CRI → primary L11 of ignition coil" until it is turned off (OF
Thyristor 5CRI, which was in the F) state, turns on. Then, the electric charge of the previously charged capacitor CI is rapidly discharged in the order of "capacitor C1→thyristor 5CRI→primary L11 of the ignition coil". As a result, a high voltage is generated on the secondary side of the ignition coil, causing sparks to fly to the spark plug and igniting the air-fuel mixture in the combustion chamber. This will start the engine.

After that, the same action caused the sparks to fly to other spark plugs one after another.
It ignites. The ignition timing at this time is the starting ignition timing, which is several positions advanced from the fully closed ignition timing to improve starting performance.

The engine temperature sensor SEI mounted on or near the cylinder head uses a thermistor, and has a characteristic that the resistance value decreases as the temperature increases, as shown in FIG. If the cylinder temperature is low and below to("C),
Set the microcomputer so that the thermistor's resistance value is 80 or more and the starting advance time is T, (seconds).On the other hand, if the cylinder temperature is high < t + ("c) or more, the thermistor's resistance value is becomes less than Ro, and the starting advance time becomes T2 [
seconds] in the microcomputer circuit. The relationship between T, , T2 (seconds) is set in advance as T, > T2.

When the starting ignition timing setting time T or T2 (seconds) has elapsed, the microcomputer circuit 52 controls the pulser coil output waveform to start with the negative side output, and the gear count coil 6 generates an output as shown in FIG. Then, the microcomputer circuit 52 counts this waveform. And throttle sensor 1
After counting the number of pulses of the output of the gear count coil 6 from the signal No. 2, it is determined whether to output a signal after the trigger output buffer.

In addition, after the starting advance angle time T1 or T (seconds) has elapsed, the switch circuit 54 is turned on (ON) L, and the pulser coil 2~
Since the positive side output of No. 5 is bypassed, it does not affect the ignition timing determination to the same extent.

The trigger output buffer outputs the signal to the gates of the cylinder thyristors 5CRI to SCR, 4, which are at the ignition timing at that time, turning on the thyristors and finally causing the spark to fly. Then, signals from the microcomputer circuit 52 are sequentially output from the trigger output huffer to the gates of the thyristors for each cylinder.

This will be explained based on the flowchart in FIG. 8 and the characteristic curves in FIGS. 3 and 6.

First, when starting the engine, the engine temperature is low.

If below [°C], lamp sensor (thermistor) SE
The resistance value of L is RO (03 or more).

At this time, to explain using the flowchart in FIG. 8, the engine starts and the engine speed at this time is the minimum possible rotation speed NI (rpm
) or more. In other words, it is determined whether or not the crank is rotating. N+Crpm:l
If it is below, it is determined that the engine has stopped and the process returns to normal. N+
(rpm) or more, it is determined that the crank is rotating, and the ignition timing becomes IT at the starting advance angle.However,
It is assumed that the throttle valve is fully closed at this time.

Next, it is determined whether the engine temperature is equal to or higher than t("c).

First, if the answer is NO, it is determined whether T1 seconds have elapsed or not, and the process returns to the original state and repeats the determination until it becomes YES. When the result is YES, the starting advance angle ends and the process shifts to the trolling ignition timing FT.

Also, if the engine temperature is to('Ca1 or higher (yes), it is determined whether T2 seconds have elapsed, but if it is no, it returns to the original state and repeats the determination.If yes, the trolling ignition timing IT is determined. Transition.

Next, various warning operations will be explained.

Optical measurement is used to check the oil level in the oil tank and whether the oil is flowing normally when separately refueling two-stroke engines commonly used in outboard motors, and to detect engine overheating. It is carried out. If any abnormality is determined through these checks, the microcomputer circuit 52 is equipped with a rotation speed control function that not only sounds the buzzer but also lights up the LED and prevents the engine speed from exceeding the set rotation speed. There is.

First, let us explain what happens when the oil level reaches the warning level. When the oil reaches the warning level, the oil level sensor SE2 turns on (ON). Current flows from battery to resistor 5 to LEDI to oil level sensor to ground. And the buzzer sounds and the LED
When the I light turns on, current from the interface circuit 60 flows from diode D14 to oil level sensor to ground J, and if the engine is being driven at a speed higher than the set rotation speed at that time, engine speed regulation is activated and the driver is alerted to the oil level. Let me know when you have reached the level.

Further, when the rotation regulation is activated, an LED lighting output is output from the LED lighting circuit 62 connected to the microcomputer, and the LED 4 is turned on. This allows the driver to confirm that rotation regulation is in operation.

Next, the overheat warning operation will be explained.

The engine temperature sensor SEI, which functions as a sensor for detecting engine overheat, shares the sensor (thermistor) used for switching the advance angle time at startup, which was explained earlier, so the relationship between temperature and resistance value is It will look like Figure 6. On the other hand, the engine temperature rise characteristic is as shown in FIG. FIG. 9 shows a flowchart from abnormality detection to warning operation.

First, start the engine as shown in Fig. 7, and after starting operation, 1
If the cooling water stops circulating to the cylinder at point 4 due to some abnormality, the engine temperature will begin to rise rapidly. Then, it reaches t+("c") (at this time, the resistance value of the thermistor of the sensor is R1 [Ω], the microcomputer circuit 52 determines that there is an abnormality in the engine cooling system, and the point A of the interface circuit in Figure 1 is at a high level. Since it becomes a low level from
Current flows in the order of "battery → buzzer → diode Dll → interface" and "battery → resistor 3 → LED 1 → interface", and the buzzer sounds and the LED I lights up, warning the driver of overheating. Also, it is determined whether the engine rotation speed at this time is above or below Nz [rpm], and if it is below, the overheat warning release temperature t'+ ["c: + (resistance value at this time R", [Ω
]) Determine whether it is less than or equal to or greater than. If this is the case, the buzzer continues to sound and the LED lights to turn on. On the other hand, if the temperature is below, it is determined that the temperature has returned to normal, and the point A of the interface circuit goes from low level to high level, so the buzzer sounds and the LEDI lights are turned off.

In addition, when the engine speed is N2 [rpm: 1 or more, the engine speed regulation (this cuts spark plug flying) is activated, and the engine speed is regulated to Nz (rpm) regardless of the throttle opening. Prevents engine temperature from rising. At this time, the LED 4 lights up to notify the driver that the rotation regulation is operating.

Therefore, the buzzer B1 will sound, and the LEDI and LED4 will turn on.

This rotation regulation is achieved by returning the throttle and reducing the engine rotation to N.
It is released when the speed becomes less than z (rpm). Of course, if the cooling abnormality is corrected and the engine temperature drops below 1'[''C], these warnings and rotation restrictions will be canceled.

Thus, in this embodiment, the entire device operates as described above. Therefore, the lamp sensor for starting special angle control and the overheat detection sensor can be used in common without affecting the overall performance, which simplifies the process and allows selection of the optimal location. The detection sensitivity can be stabilized, and furthermore, the wiring and control circuit can be simplified, so there are great advantages in terms of production costs.

〔Effect of the invention〕

As described above, according to the present invention, since each temperature sensor for starting special advance angle control and overheat detection is provided by a single temperature sensor, it is possible to maintain high ignition performance at the time of starting and to maintain high performance. Overheating can also be detected, the equipment is simplified, the cost of the entire device can be reduced, and maintenance for discovering failures is easy, and it is easy to handle, making it an unprecedented engine ignition system. A timing control device can be provided.

[Brief Description of the Drawings] Fig. 1 is a circuit configuration diagram showing one embodiment of the present invention, Fig. 2 is an explanatory diagram showing a magneto including a pulsar coil in Fig. 1, and Fig. 3 is an explanatory diagram showing a magneto including a pulsar coil in Fig. 1. An explanatory diagram showing the starting advance angle pattern, Fig. 4 is a diagram showing the output waveform of each coil in Fig. 1, Fig. 5 is an explanatory diagram showing an example of the mounting position of the temperature sensor, and Fig. 6 is an explanatory diagram showing the output waveform of each coil in Fig. 1. Figure 1 is a diagram showing the characteristics of the temperature sensor (thermistor), Figure 7 is an explanatory diagram showing an example of the temperature rise characteristics of the engine, Figure 8 is a flowchart showing advance angle control when starting the engine, Figure 9 is a flowchart showing a procedure for warning operation of engine overheating. B1... Buzzer as a warning means, SEI... Temperature sensor, 52... Main control unit. Applicant Suzuki Motor Co., Ltd. Agent Patent Attorney Isamu Takahashi Figure 2 (7 Kuunetoo^tboen), 3 (Ha/L1- KoinoL) /' Atenor/iLee Koinol) Figure 3 (lkhLalw 9-Q) [Japanese FF Ha 11] Figure (8 car IL mountain power n ◇) Figure (tan) itl' 212 Tori Iden Iku 9) Figure 6 (Two S star erection J, !') (I C (niiiiiiiii) (completed to A) turbidity diagram (Kanto-Surikaku Flow Hand Sei Ln Diagram (Enono y7 Yuru Kamito 71 Yu) r --- ------ National Customs 1 Figure 9

Claims (1)

[Claims] (1) A temperature sensor installed in or near the cylinder head, an alarm means for issuing an alarm to the outside when this temperature sensor detects an overheating state of the engine, and an output signal from the temperature sensor is input. and a main control section that drives the alarm means and regulates an increase in engine speed as necessary, and the main control section further constantly inputs an output signal from the temperature sensor before starting the engine. An engine ignition timing control device characterized in that it is equipped with a start-up ignition timing control function that performs advance angle control at engine start-up based on engine temperature information sent from the temperature sensor.