JPS606074A - No-contact ignition device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To delay the angle of ignition timing by a simple structure at the time of overrunning by providing a sensor coil to generate AC output signals at fixed intervals in the turn of negative and positive. CONSTITUTION:A sensor coil 9 generates one-cycle signals of different polarities in the turn of negative and positive. When a control condenser 11 is charged into an illustrated polarity by the first negative half-wave of this sensor signal, a negative bias is given to an A-point. When the number of revolutions comes to an overrunning value, the electric potential at the A-point is rapidly reduced. Consequently, the amount of delay angle is increased as the number of revolutions is increased. This construction permits to delay the angle of ignition timing by a simple structure at the time of overrunning.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a capacitor discharge type ignition device for an internal combustion engine.

For the purpose of preventing overrun, preventing seizure of a two-cycle engine, etc., the ignition timing characteristic of starting retarded from the set rotational speed N1 as shown in FIG. 1 may become a-key. ' In response to such demands, JP-A-11-52
- As shown in Publication No. 3941, Sensa Koino 1 and jl
It is known that a transistor is connected to the IE column and the transistor is operated at a set rotational speed to reduce the input impedance of the G1 circuit, but this method has the problem described in F.

■The circuit configuration becomes complicated, resulting in a large increase in cost.

(?) Sensor signal 1+]2 retardation cannot be obtained. (The middle waveform of "retard medium amount" is "a") Therefore, in order to solve the above-mentioned problem, the present invention uses a series circuit of a resistor and a capacitor in parallel with the sensor coil (before the diode). By first applying a negative 4' wave as a sensor signal and then applying a positive half wave after an arbitrary angular interval α° of -4, the signal in Fig. 1 can be retarded by more than the sensor reliability with a simple configuration. The purpose is to be able to adjust the ignition timing characteristics.

Embodiments of the present invention shown in the drawings will be described below.

In Figure 2, 4″?-ζ1.■ is the capacitor charging coil, 2 is the ignition capacitor, 3 is the ignition coil, 4 is the ignition coil.
is a spark plug, 5 is an ignition cylinder, 6, 7. ε3 is a diode, and 9 is a sensor coil, which generates one cycle of alternating current signals in the order of positive and negative intervals of α. (See Figure 3). 1 with this Senzu coil 9! As shown in Fig. 5, the structure of the 1st section is such that long protrusions 13 are formed on the outer periphery at an angle equal to the signal interval α, and the sensor 16 has a built-in magnet 1. do.

] 0 is a resistance (several ohms to several hundred ohms), 10 is a control capacitor (0.1 to several μF), and resistor 10 is a capacitor 11
Set the charging/discharging time constant.

FIG. 5 is a structural diagram of the sensor section, in which 12 is a + router, 13 is a lattice protrusion (which forms an inductor, and is constructed by stamping or welding a magnetic material to the outer periphery of the +7-tater 12), 1
4 is a magnet, and 15 is a sensor core (the capstone 14 and the long protrusion 13 constitute a magnetic path).

In the above configuration, when the rotor 12 rotates and the elongated protrusion 13 faces the sensor core 15, magnetic flux changes within the sensor core 15 cause a signal waveform of one cycle with different polarity and a signal interval approximately equal to the angle of the elongated protrusion 13 to be generated. Occurs in the following order. (Figure 3).

By charging the control capacitor 11 to the polarity shown (FIG. 2) with the first negative half wave of this sensor signal (waveform a in FIG. 3), point A is biased negatively.

The electric charge charged in this :1 capacitor 11 is discharged at a time constant ζ determined by the inductance and internal resistance of the sensor coil 9, the resistor 10, and the capacitor 11, and the potential at point A returns to OV.

At low speeds below the retard start setting rotation speed N, capacitor 1
The charge charged to 1 is the positive half wave of the 90th order of the sensor coil (
Figure 3 waveform) Discharge occurs before the rise, and the potential at point A is QV.
Since the ignition timing returns to C, the ignition timing is determined by the rising position of the b waveform.

When the rotation speed increases by -L and the retardation start rotation speed reaches N1 or higher, the Δ point is still negatively biased at the start of the b-branch rise, so the b waveform The start-up is delayed and the ignition timing is retarded.

Furthermore, as the rotation speed increases from N1 to N2 to N4, the potential at point A at the rising edge of the b waveform becomes lower and lower, as shown in Figure 4 (1), so as the rotation speed increases, the retard angle increases, and the set rotation The ignition timing performance shown in FIG. 1, which is linearly retarded, can be obtained from the number N1.

Here, T L in FIG. 4 indicates the trigger level of the thyristor 5.

The retardation start rotation speed N1 and the setting during retardation ('', the interval α between the negative and positive waveforms of the sensor signal (, 3, the interval between the b waveforms), the angle of the long protrusion 13, and the discharge time constant of the capacitor 11 (Change the capacitance of capacitor 1 and resistance 1.0.)
Do it by doing this.

In addition, with this method, even if the negative bias at the Δ point is large and the potential at the A point does not return to 0■ until the end of the no-load voltage waveform of the b waveform, such as N4 in Fig. 4, the sensor Inductance of coil 16 and capacitor 11 (
Since a stationary waveform is generated, there is no chance of ignition failure, and even during retardation, there is no restriction due to the sensor waveform +1 as in the conventional system, and a wide range can be obtained. In experiments, a retard angle of 40 degrees was obtained in the present invention, compared to a retard angle of 5 degrees in the conventional system.

In the above-described embodiment, a case has been described in which an inductor rotation type sensor is used, but as shown in FIG. 6, a magnet 17 is fixed to the outer periphery of the rotor 12.

Even if a rotating magnet type sensor is used, it can be used as long as the sensor signal waveform is generated in the order of negative and positive.

[Brief explanation of drawings]

FIG. 1 is an ignition timing characteristic diagram obtained by the device of the present invention, FIG. 2 is an electric circuit diagram showing an embodiment of the device of the present invention, and FIG. 3 is a diagram of the output signal waveform of the sensor coil in the above embodiment.
FIG. 4 is a voltage waveform diagram at point Δ in the embodiment shown in FIG.
FIG. 5 is a partial cross-sectional plan view showing the structure of the sensor portion on the recording side, and FIG. 6 is a partial cross-sectional plan view showing another embodiment of the sensor portion. 5...Silisk for ignition, 8...Guimate, 9.
・Senzacoil, 10...Resistor, 11...Control condenser. Representative Patent Attorney Takashi Okabe Figure 5 1 et al. 6 Figure 475-

Claims (1)

[Claims] It is equipped with a sensor coil that generates alternating current output signals in the order of negative and positive at regular intervals, and a series circuit of a resistor and a capacitor connected in parallel with the sensor coil.
・A non-contact ignition device for internal combustion, in which the dili is connected to the gate of the ignition thyristor via a diode.