JPS6062663A - Ignition-timing controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the starting performance of an engine by allowing the pulser coil of an ignition-timing controller for internal-combustion engine to generate the positive and negative pulser voltages in pair between which a voltage difference exists and executing ignition by said pulser voltage and advance-controlling the ignition timing in step form. CONSTITUTION:In a condenser discharge type ignition apparatus, a charge coil 1 is connected to a condenser 3 through a rectifying diode 2. The part between the diode 2 and the condenser 3 is grounded through a thyristor 4 as ignition switch, and the thyristor 4 is opened by the pulser signal output from a pulser coil 8, and ignition is performed by a plug 7 connected to the secondary side of an ignition coil. Therefore, the positive and negative pulser voltages in pair are generated by the pulser coil 8, and the pulser voltage early generated is made smaller than the pulser voltage lately generated, and the lately generated pulser voltage is input into the thyristor 4 when an internal-combustion engine is at low revolution speed, and the early generated pulser voltage is input into the thyristor 4 when the engine is at high revolution speed.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an ignition timing control device for an internal combustion engine.

Conventionally, as an ignition system for internal combustion engines such as two-stroke engines, the ignition switch is opened by the pulsar Nobigata output from the pulsar coil, and the internal combustion engine is ignited by the ignition plug connected to the secondary side of the ignition coil. There is an ignition timing control device for internal combustion engines. Conventionally, this type of device uses an electronic advance method in which a pulser coil is provided outside the rotor, and the output voltage of the pulser coil operates a thyristor to control the ignition position. In addition, multi-pole magnetos are now being used in small motorcycles and other vehicles due to the increase in the output of generators. The pulsar coil is installed outside the rotor, and the signal from the pulsar coil operates the sirisk to control the ignition timing. However, all of these electronic advance angle systems had complicated structures.

This invention was made against the background of the above circumstances, and has a simple and inexpensive structure for advancing the ignition timing, and is suitable for use in internal combustion engines to improve the startability of engines such as motorcycles. The purpose is to provide an ignition timing control device.

In order to achieve the above object, the present invention generates a pair of positive and negative pulsar voltages in a pulsar coil, and makes the pulsar 'L [pressure of the first of these pulsar voltages smaller than the pulsar voltage that is generated later, and When the engine is at a low rotation speed, the pulsar voltage that is output later is input to the ignition switch, and when the engine is at a high rotation speed, the pulsar voltage that is output first is input to the ignition switch to control the advance angle. It is characterized by

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic circuit configuration of an ignition timing control device in a capacitor discharge type ignition device, in which a charging coil 1 is connected to a capacitor 3 via a rectifying diode 2. The diode 2 and the capacitor 3 are grounded via a thyristor 4 as an ignition switch. The capacitor 3 is further connected to the primary side 5 of the ignition coil, and the spark plug 7 is connected to the secondary side 6 of the ignition coil. The capacitor 3, the thyristor 4, and the primary side 5 of the ignition coil constitute a series circuit. Further, a pulsar voltage from a pulsar coil 8 is applied to the gate of the thyristor 4.

The charge coil 1 and the pulser coil 8 are incorporated into a multipolar magneto.

FIG. 2 shows this magneto, which is composed of a rotor A that rotates in synchronization with the engine crank 1liil+ and a stator B disposed inside the rotor A. Rotor A
A plurality of permanent magnets 10, for example, eight permanent magnets 10 having mutually different magnetisms, are arranged at equal intervals in the circumferential direction on the inner surface of a rotor body 9 made of a magnetic material and shaped like a force pump. In contrast to such a rotor A, a stator B has a charging coil 1 wound around each iron core ll facing a permanent magnet 10, and three charging coils 1 are arranged between the N pole of the permanent magnet 10 and Sa. There is.

Further, the pulsar coil 8 is located outside the rotor body 9 and is wound around the magnet 12.

A protrusion 13 is formed on the outer periphery of the rotor 9.
Pulsar voltages having opposite polarities at both ends of the protrusion 13 are obtained by the pulser coil 8. The protrusion width (angle) D of this protrusion 13 corresponds to the maximum advance width (angle) as shown in FIG. Output lines 14 and 15 are connected to both ends of this pulser coil 8, and the output line 14 is connected to a CR between a capacitor 19 and a resistor 20 through a diode 16, and a -power output line 15 through a diode 17 and a resistor 18. The CR parallel circuit is connected to a parallel circuit, and the output line of this CR parallel circuit is connected to the gate of the thyristor 4.

Next, the operation of this embodiment will be explained. First, when the rotational speed of the engine is low, such as N or lower in FIG. A positive pulser voltage is obtained by the direction end portion 13b.

This negative pulser voltage a is voltage-dropped at the resistor 18 as shown in FIG.

The next positive pulsar voltage is the diode I6.
and is applied to the gate of thyristor 4 via a CR parallel circuit. Unlike the negative pulser voltage a, this pulser voltage does not have a voltage drop across the resistance and is higher than the set level L, so it can be input to the gate of the thyristor 4 via the CR parallel circuit. In this way, when a positive pulser voltage is applied to the gate of thyristor 4, it becomes energized and capacitor 3
The charged voltage is discharged through the thyristor 4. This discharged current is the primary f of the ignition coil
When the current flows to 1σ5, a high voltage is generated on the secondary side 6 of the ignition coil and fireworks are generated at the ignition plug 7, so that the air-fuel mixture is ignited.

The ignition position at this time is ignition position α, as shown in Fig. 4.
The angle is not advanced.

When the rotational speed of the engine increases and reaches N in FIG. Since the voltage is higher than the set level L, this pulser voltage is applied to the gate of the thyristor 4 via the CR parallel circuit, and the above-mentioned ignition operation is performed. As a result, the ignition position advances in a stepwise manner from α to β as shown in FIG. The advance angle width is set by the protrusion width of the protrusion 13 of the rotor main body 9, and the rotational speed of the engine when advancing the angle can be arbitrarily set by the value of the resistor 18.

In addition, in the case of a 3-phase generator, stable 3-phase output can be output unless 3 charge coils are placed between the N pole and the S pole. Therefore, the number of permanent magnet poles is 8.
In the case of poles, 45 degrees will be Magne and Tobich, and in the case of 12 poles, it will be 30 degrees. Therefore, in order to create an AC waveform of 1 cycle, in the case of 8 poles it is 90 degrees, and in the case of 12 poles it is 6 degrees.
It needs to be 0 degrees.

The phase of the above-mentioned coil can be reversed by switching the winding start and winding end positions, that is, the winding directions. Therefore, by shifting the magnet pitch, the voltages generated by the charge coil and the power supply coil can be made to have opposite phases.

Further, the rotor main body 9 is not limited to the protrusion 13, but may have four parts.

As described above, this invention generates a pair of positive and negative pulsar voltages in the pulsar coil, and creates a voltage difference between the pair of pulsar voltages, so that at low rotational speeds, the pulsar voltage is generated later, and at high rotational speeds, the pulsar voltage is generated first. Since ignition is performed using the generated pulsar voltage, it is possible to control the ignition timing of the internal combustion engine by advancing it in a step-like manner, improving engine operability and allowing it to operate with a pair of pulsar voltages. The structure is simple and inexpensive.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic circuit diagram of the ignition 11-1-phase control device line in a capacitor discharge type ignition system, and FIG. 2 is a diagram of the configuration of a multi-pole magneto. FIG. 3 is an explanatory diagram of the operation of this embodiment, and FIG. 4 is an ignition position diagram showing the ignition position. ■...Charge coil 3...Capacitor 4...
・Thyristor 8...Pulser coil 9...Rotor body 13...Protrusion 16.17...Diode 1
8...Resistance Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In an ignition timing control device for an internal combustion engine, in which an ignition switch is opened by a pulsar signal output from a pulsar coil and ignites an ignition plug connected to a secondary side of the ignition coil, the pulsar coil A pair of pressure-negative pulsar voltages are generated, the pulsar voltage that is generated first among the pulsar voltages is made smaller than the pulsar voltage that is generated later, and when the internal combustion engine is at a low rotational speed, the pulsar voltage that is output later is An ignition timing control device for an internal combustion engine that performs advance control by inputting the pulsar voltage that is output first to the ignition switch when the rotation speed is high.