JPS6132152Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition position for an internal combustion engine that electrically controls the ignition position according to the rotational speed of the engine.

Generally, in an internal combustion engine, it is necessary to control the ignition position according to the rotational speed of the engine. For example 4
In a cycle internal combustion engine, as shown in Fig. 1, ignition is performed at a substantially constant ignition position θ _a from the idling speed N ₁ (rpm) to the set speed _{N 1} (rpm), rpm) to _N2 (rpm)
In the medium to high speed rotation range up to, an advance characteristic is required in which the ignition position θ _i is advanced by an angle θ _w (advance width) from θ _a to θ _b . In the figure, TDC is the top dead center of the engine piston, and BTD・C is the bottom dead center. The applicant previously proposed the ignition position shown in FIG. 2 as an ignition position that provides such advance angle characteristics. In Fig. 2, a is the ignition position control capacitor that is charged from the DC power supply circuit _Vcc through the constant current circuit b and the discharge blocking diode c, and d is the current that constitutes the discharge circuit that discharges the capacitor a at a constant time constant. The limiting means e is a discharge section control switch, and the negative direction output of a signal coil f which emits a signal at a predetermined rotation angle position of the engine is inputted to a control terminal of the switch e via a diode g. Further, h is a voltage comparator, and the terminal voltage of capacitor a and the reference voltage V _r obtained from the reference voltage generation circuit i are input to this voltage comparator, and the terminal voltage of capacitor a becomes below the reference voltage V _r . A signal obtained from the voltage comparator h at this time is input to the ignition circuit k via the diode j as a signal (ignition signal) for determining the ignition position. As shown in Fig. 3B, the signal coil f generates one negative direction signal E every time the engine rotates once.
_s1 and one positive direction signal E _s2 , and the discharge section control switch e is made conductive during the period when the negative direction output E _s1 is generated in the signal coil f. Further, the positive direction output _Es2 of the signal coil f is supplied as an ignition signal to the ignition circuit k via a diode, and at the same time is supplied to the control terminal of a reset switch m connected in parallel to both ends of the capacitor a. Note that in a section where no output is generated in the signal coil f, no ignition signal is applied to the ignition circuit k. The ignition circuit k generates a high voltage on the secondary side of the ignition coil by suddenly changing the primary current of the ignition coil at the ignition position using an exciter coil _Ex distributed in a magnet generator driven by an internal combustion engine as a power source. The ignition energy to the ignition coil is normally given by the output of the exciter coil _Ex in a half cycle (hereinafter referred to as a positive half cycle) in the direction of the solid arrow shown in the figure. Here, the DC power supply circuit V _cc is
It consists of a circuit that stores the output of the exciter coil _Ex in a half cycle (hereinafter referred to as a negative half cycle) in the direction of the dashed arrow in a capacitor via a diode, and the charge stored in this capacitor is constant. The current is supplied to capacitor a through current circuit b and diode c.

In the above ignition system, the waveform of the terminal voltage V _a of the capacitor a with respect to the rotation angle θ is, for example, shown in FIG.
As shown in , the signal coil f rises at a constant slope from the rising position θ _c of the positive direction output E _s2 to the rising position θ _b of the next negative direction output E _s1 (constant current charging).
The waveform then descends at a constant slope (constant current discharge) from the angle θ _b to the next angle θ _a . In this ignition device, in the region below the set rotational speed _N1 , the ignition signal is given to the ignition circuit k at the rising position _θa of the positive direction output _Es2 of the signal coil f, so ignition is performed at this position _θa , Set rotation speed N ₁
In the range from N2 to _N2 , as shown in FIG. 3A, an ignition signal is given at a position θ _i where the terminal voltage _V a of the capacitor a becomes less than the reference voltage V _r . Since the charging voltage _V a of the capacitor a at the angle θ _b decreases as the rotational speed of the engine increases, the ignition position θ _i advances as the rotational speed of the engine increases. Further, in a region where the rotational speed is equal to or higher than the set rotational speed _N2 , an ignition signal is given at a position _θb where the negative direction output _Es1 of the signal coil f rises.

According to the above-mentioned ignition device, there is no need to control the charging current and discharging current of the capacitor a according to the rotation speed, and since the charging and discharging sections of the capacitor are controlled by one switching element,
The driving circuit for the switching element can also be simplified, and precise ignition position control can be performed without using a complicated circuit. Also, since the control circuit is simpler, less power is required to control the ignition position, and even if the control circuit is operated using part of the output of the magnet generator that supplies ignition energy, it will not affect the ignition energy. It has the advantage of being almost non-existent. However, in the above ignition device,
It has become clear that when a capacitor discharge type ignition circuit is used as the ignition circuit K, the ignition performance at high speeds deteriorates. That is, the capacitor discharge ignition circuit charges an ignition energy storage capacitor to one polarity with the output of the positive half cycle of the exciter coil _Ex , and discharges this capacitor through the primary coil of the ignition coil at the ignition position. However, if the capacitor of the DC power supply circuit _Vcc is charged during the negative half cycle of the exciter coil _Ex as shown in Fig. 2, the DC Due to the armature reaction caused by the current flowing into the capacitor of the power supply circuit _Vcc , the rise of the output of the exciter coil _Ex in the next positive half cycle is delayed, and charging of the ignition energy storage capacitor tends to be delayed. Therefore, especially when the engine is running at high speed, the ignition operation is performed without sufficient energy being stored in the ignition energy storage capacitor, resulting in a decrease in ignition performance.

The purpose of this invention is to prevent the ignition performance from deteriorating due to armature reaction by eliminating the need for current to flow through the large exciter coil during the half-cycle period when the ignition energy storage capacitor is not being charged. The purpose of this invention is to provide an ignition device for

The present invention provides control during one half cycle of the exciter coil that charges the ignition energy storage capacitor of the ignition circuit when a capacitor discharge type ignition circuit is used in the ignition system for an internal combustion engine as shown in Fig. 2. The power supply capacitor is charged to a constant voltage, and the ignition position control power supply capacitor a is charged with a constant current using the charge of the control capacitor. In order to avoid affecting the charging of the ignition energy storage capacitor, the control power supply capacitor is charged after the output of one half cycle of the exciter coil reaches a set value. With this configuration, since no current flows through the exciter coil during the other half cycle of the exciter coil, there is no delay in the rise of the output in the next half cycle due to armature reaction. Therefore, there is no delay in charging the ignition energy storage capacitor, and ignition performance at high speeds does not deteriorate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ignition device for an internal combustion engine of the present invention will be explained in detail below with reference to the illustrated embodiments.

FIG. 4 shows an embodiment of the present invention, in which 1 is an exciter coil installed in a magnetic alternator that rotates synchronously with an internal combustion engine (not shown), 2 is a primary coil 2a and a secondary This is an ignition coil having a coil 2b. As a normal generator, 4
In this embodiment, a four-pole magnetic alternator is used, and the exciter coil 1 has two cycles of alternating current per one revolution of the engine crankshaft, as shown in FIG. 5A. The voltage V ₁ is induced. A thyristor 3 serves as a discharge control semiconductor switch for controlling the discharge of the ignition energy storage capacitor 4, and one end of the exciter coil 1, one end of the primary coil 2a, and one end of the exciter coil 3 are commonly connected and grounded. ing. Capacitor 4 is connected between the non-grounded terminal of primary coil 2a and the anode of thyristor 3,
The connection point between the capacitor 4 and the anode of the thyristor 3 is a diode 5 and a resistor 6 with a sufficiently large resistance value.
The exciter coil 1 is connected to the non-ground terminal of the exciter coil 1 through a parallel circuit with the exciter coil 1. The diode 5 is connected in such a direction that a charging current flows through the capacitor 4 at the half-cycle (positive half-cycle) output of the exciter coil 1 in the direction of the solid arrow shown in the figure, and the capacitor 4 has a terminal voltage V ₄ as shown in FIG. 5B. As shown in the waveform, the positive half-cycle output of the exciter coil 1 charges the polarity shown in the figure through the diode 5 and the primary coil 2a. When an ignition signal is applied to the thyristor 3 at the ignition position of the engine, the thyristor 3 becomes conductive and the charge in the capacitor 4 is discharged through the thyristor 3 and the primary coil 2a, and the secondary coil 2b
High voltage induces This high voltage is applied to the secondary coil 2
The voltage is applied to the ignition plug 7 connected to the ignition plug 7, a spark flies to the ignition plug 7, and the engine is ignited. The exciter coil 1, ignition coil 2, thyristor 3, capacitor 4, diode 5, resistor 6, and spark plug 7 constitute a capacitor discharge type ignition circuit. Incidentally, in this ignition circuit, the positions of the capacitor 4 and the thyristor 3 may be interchanged so that the charging current of the capacitor 4 does not flow through the primary coil 2a, and the resistor 6 may be omitted.

In the above-described ignition circuit, the ignition position can be controlled by controlling the phase of the ignition signal (conduction signal) given to the thyristor 3 (semiconductor switch for discharge control).

In this embodiment, in order to control the ignition position according to the rotational speed of the engine, the ignition position control circuit 10
will be provided. To configure this control circuit, a resistor 11 is connected in parallel between the gate and cathode of the thyristor 3, and a signal coil 13 is connected in parallel to both ends of the resistor 11 via a diode 12. The signal coil 13 is provided either in the magnet generator in which the exciter coil 1 is arranged or in a separate signal generator and induces a signal of one cycle per revolution of the engine. The non-grounded terminal of the signal coil 13 is connected to the base of an NPN transistor 15 via a thyristor 50 whose cathode is on the signal coil side, and the emitter of the transistor 15 is grounded. The anode is grounded between the base and emitter of transistor 15 (transistor 1
A diode 16 is connected in parallel to the emitter of the transistor 15, and a connection point between the cathode of the diode 16 and the base of the transistor 15 is connected to one end of a resistor 17. Further, the collector of the transistor 15 is connected to one end of a resistor 19, and the other end of the resistor 19 is commonly connected to the other end of the resistor 17. One end of a resistor 20 is connected to a connection point between the resistor 19 and the collector of the transistor 15, and the other end of the resistor 20 is connected to the gate of the thyristor 3 via a diode 21. A resistor 51 is connected in parallel between the gate and cathode of the thyristor 50, and a Zener diode 52 whose anode is on the gate side of the thyristor is connected in parallel between the gate and anode. The thyristor 50 becomes conductive when the output (in the direction of

In order to configure the control power supply circuit of the control circuit 10,
One end of a control power supply capacitor 61 is connected to the ground terminal of the exciter coil 1, and the capacitor 61
A cathode of a diode 62 is connected to the other end. In addition, a first terminal is connected to the non-grounded terminal of the exciter coil 1 to control charging of the capacitor 61.
The anode of the thyristor 63 is connected, and the cathode of the thyristor 63 is connected to the anode of the diode 62. A series circuit of a resistor 64 and a variable resistor 65 is also connected in parallel to both ends of the exciter coil 1, and the connection point between the resistors 64 and 65 is a Zener diode 6 with the cathode on this connection point side.
6 to the gate of the thyristor 63. Anode of diode 62 and thyristor 6
The anode of a second thyristor 67 whose cathode is grounded is connected to the connection point with the cathode of No. 3, and a Zener diode 68 whose cathode is on the anode side of this thyristor 67 is connected in parallel between the anode gate of the second thyristor 67. It is connected. In addition, a resistor 6 is connected between the gate and cathode of the thyristor 67.
9 are connected in parallel, and the capacitor 61 to the resistor 69
A control power supply circuit 60 is constituted by each part.

In the control power supply circuit 60, when the positive half-cycle output of the exciter coil 1 rises at an angle θ ₁ , the ground voltage _V a of the anode a of the first thyristor 63 is the same as the terminal voltage V ₄ of the capacitor 4. It rises in a waveform. When charging of capacitor 4 is almost completed and voltage V _a reaches the set value at angle θ ₂ ,
The voltage obtained by dividing this voltage V _a by the resistors 64 and 65 reaches the Zener level of the Zener diode 66, and the Zener diode 66 becomes conductive. As a result, an ignition signal is supplied to the first thyristor 63, and the first thyristor 63 becomes conductive. Therefore, the control power supply capacitor 61 is charged from the exciter coil 1 through the first thyristor 63 and the diode 62 to the polarity shown, and the terminal voltage V _c of the capacitor 61 rises as shown in FIG. 5E. At an angle θ ₃ , the terminal voltage of the capacitor 61 reaches a constant voltage V _p , and the second thyristor 6
When the potential V _b of the anode 7 reaches a predetermined value V _p ', the Zener diode 68 is brought into communication and an ignition signal is supplied to the second thyristor 67. This causes the second thyristor 67 to become conductive and stop charging the capacitor 61. Therefore, the charging voltage of the capacitor 61 is always a constant value V _p . Since the electric charge of this capacitor 61 is used to fully charge an ignition position control capacitor 31 (to be described later), the terminal voltage of the capacitor 61 decreases at a constant slope. The first and second thyristors 63 and 67, the Zener diodes 66 and 68, the resistors 64, 65 and 69, and the diode 62, when the output of the positive half cycle of the exciter coil 1 reaches the set value. A constant voltage charging circuit is configured to charge the control power supply capacitor 61 to a constant voltage.

One end of the control power supply capacitor 61 on the non-grounded side is connected to the common connection point of the resistors 17 and 19, and also to one end of the constant current circuit 29. The constant current circuit 29 is, for example, a known circuit in which the gate of a field effect transistor is coupled to the source via a resistor or directly, and a capacitor for controlling the ignition position is connected between the other end of the constant current circuit and ground via a diode 28. 31 is connected. One end of the capacitor 31 on the non-grounded side is connected to the collector of an NPN transistor 33 via a constant current circuit 32, and the emitter of the transistor 33 is grounded. The base of the transistor 33 is grounded through a resistor 34 and connected to the collector of the transistor 15 through a resistor 35, and the collector of the transistor 33 is connected to the anode of the diode 28. In addition, a resistor 36 and a Zener diode 37 are connected between the non-grounded terminal of the capacitor 61 and the ground.
The series circuit with Zener diode 3 is connected.
The reference voltage V _r obtained across the voltage comparator 3
It is input to the positive side input terminal 38a of No.8.
The voltage V _d across the ignition position control capacitor 31 is input to the negative input terminal 38b of the voltage comparator 38.
is input, and the non-grounded output terminal 3 of the comparator 38
8c is connected to the gate of the thyristor 3 via a diode 21. Further, the power supply terminal 38d of the voltage comparator 38 is connected to a line connected to the non-grounded terminal of the capacitor 61. Although not shown, the voltage comparator 38 includes a switching element connected between the output terminal 38c and the ground at the final stage, so that the terminal voltage V _d of the capacitor 31 is set to the reference voltage V _r
When the voltage is higher, the output terminal 38c is set to the ground potential,
The output terminal 38c is configured to be ungrounded when the terminal voltage _Vd becomes equal to or lower than the reference voltage _Vr . Therefore, when the terminal voltage V _d of the capacitor 31 is higher than the reference voltage V _r , the voltage comparator 38 grounds the gate and cathode of the thyristor 3 to prevent the ignition signal from being applied to the thyristor 3. When V _d ≦V _r , the ignition signal is allowed to be supplied to the thyristor 3.

A thyristor 39 is connected in parallel to both ends of the capacitor 31 with its cathode connected to the ground, and the gate of the thyristor 39 is connected to the ground terminal via a resistor 40 and connected to the signal coil 13 via the resistor 41.
connected to the non-grounded terminal of the

In the above embodiment, the capacitor 31 corresponds to the capacitor a in FIG. 2, and the resistor 36 and Zener diode 37 constitute the reference voltage generating circuit i in FIG. Further, the constant current circuit 29 and the diode 28 constitute a charging circuit that charges the capacitor 31 with a constant current to one polarity using the output of the power supply, and the diode 28 is a discharge blocking diode c shown in FIG.
It corresponds to Furthermore, in this embodiment, the second
A constant current circuit 32 is used as the current limiting means d in the figure, and a discharge section control switch for the capacitor 31 is constituted by this constant current circuit 32 and a discharge section control switch consisting of a transistor 33 and a transistor 15, and the transistor 15 is cut off. When this happens, the transistor 33 becomes conductive and the capacitor 31 is discharged. At this time, the current for charging the capacitor 31 is bypassed from the capacitor 31 by the transistor 33. Also, transistor 15, resistor 19, 2
0, and voltage comparator 38 causes capacitor 31
A conductive signal that generates a conductive signal to be applied to the thyristor 3 (semiconductor switch of the ignition circuit) when _the terminal voltage _Vd of the capacitor 31 becomes lower than the reference voltage _Vr by comparing the terminal voltage _Vd of the capacitor 31 with the reference voltage Vr. A generation circuit is configured. That is, transistor 15
serves both as a switch for controlling on/off of the discharge section control switch and as a control switch for the conduction signal generation circuit. More specifically, when the transistor 15 is in the cut-off state, the signal supplied from the capacitor 61 through the resistors 19 and 20 is allowed to be supplied to the thyristor 3;
When 5 is conductive, the supply of this signal is blocked. Furthermore, when transistor 15 becomes conductive, transistor 33 is cut off to allow charging of capacitor 31. Also, thyristor 39 and resistor 4
0 and 41 constitute a reset circuit for discharging the capacitor 31. In this embodiment, the thyristor 50, the resistor 51, and the Zener diode 52 constitute an ignition position determining circuit for starting, and the negative direction output E _s1 generated first in the signal coil 13 becomes equal to or higher than the Zener level of the Zener diode 52. The transistor 15 is turned off only when the thyristor 50 becomes conductive.

In the above ignition device, when the output terminal 38c of the voltage comparator 38 is in an ungrounded state and a signal in the direction of the solid arrow shown in the figure (hereinafter referred to as a positive direction signal) is induced in the signal coil 13, An ignition signal is supplied to the thyristor 3 through the diode 12. Further, when the output terminal 38c of the voltage comparator 38 is in the non-grounded state, the transistor 15
When the thyristor 3 is in the cut-off state, an ignition signal is supplied from the capacitor 61 to the thyristor 3 through the resistors 19 and 20 and the diode 21. Note that the resistor 17 is for flowing the base current to the transistor 15, and the resistance value of this resistor is set to be sufficiently large, so that the circuit of the resistor 17, the Zener diode 52, the resistor 51, and the diode 12, or the resistor 17, the thyristor 50, and the diode 12 The ignition signal is not supplied to the thyristor 3 through the circuit.

In the above ignition system, if the magnet generator provided with the exciter coil 1 has a four-pole structure, the exciter coil 1 receives a voltage V ₁ of two cycles per engine revolution as shown in FIG. 5A. is induced in the exciter coil 1, and a voltage in the direction of the solid arrow shown in the figure (hereinafter referred to as positive direction voltage) is induced in the exciter coil 1. During the half cycle, the capacitor 4 is charged from the exciter coil 1 through the diode 5 and the primary coil 2a. FIG. 5B shows the waveform of the terminal voltage V ₄ of this capacitor 4 with respect to the rotation angle θ of the engine. Further, as shown in FIG. 5F, for example, the signal coil 13 first generates a negative direction signal (signal in the direction of the dashed arrow in the figure) E _s1 while a positive direction voltage is induced in the generator coil 1, Then, a forward direction signal E _s2 is generated. The angle θ _a at which the positive direction signal E _s2 rises is the set rotational speed of the advance angle characteristic shown in Figure 1.
It is adjusted to the ignition position below N ₁ , and the negative direction signal E _s1
The angle θ _b at which the angle rises is matched to the ignition position at the rotational speed N ₂ or higher where the advance ends. Therefore, the width of the negative direction signal E _s1 generated by the signal coil 13 is the advance angle width θ.
Corresponds to _w .

Now, when a positive half-cycle voltage is induced in the exciter coil 1 at the angle θ ₁ in FIG. 5, the capacitor 4 is charged to the polarity shown, and then at the angle
When the voltage of the exciter coil 1 reaches a predetermined value at _{step 2} , the first thyristor 63 becomes conductive and the control power supply capacitor 61 is charged. When the terminal voltage of the capacitor 61 reaches the set value V _p at the angle θ ₃ , the second thyristor 67 becomes conductive and charging of the capacitor 61 is stopped. The terminal voltage of this capacitor 61 is
Since the voltage is applied to the base of the transistor 15 via the resistor 17, the voltage from the capacitor 61 to the resistor 17 is
A base current flows through the transistor 15 through the transistor 15. Therefore, transistor 15 is turned on and transistor 33 is turned off. Since the transistor 33 is cut off, the electric charge of the control power supply capacitor 61 is discharged to the ignition position control capacitor 31 through the constant current circuit 29 and the diode 28, and the capacitor 31 is charged with a constant current with the polarity shown. Therefore, the terminal voltage V of the ignition position control capacitor 31
_d increases linearly as shown in FIG. 5G. Next, at the angle θ _b , one (negative direction) half-cycle signal E _s1 is generated in the signal coil 13, and when this signal exceeds the Zener level of the Zener diode 52 and the thyristor 50 becomes conductive, the transistor 15 is cut off. , makes the transistor 33 conductive. Therefore, the charging current to the ignition position control capacitor 31 is bypassed from the capacitor 31 by the transistor 33, and charging of the capacitor 31 is stopped. At this time, constant current discharge is simultaneously started, and the terminal voltage V _d of the capacitor 31 decreases linearly as shown in FIG. 5G. When the terminal voltage V _d of this capacitor 31 is higher than the reference voltage V _r , the output terminal 38 of the voltage comparator 38
Since c is at ground potential, no firing signal is supplied to the thyristor 3 even if the transistor 15 is in the cut-off state.

When the terminal voltage V _c of the capacitor 31 becomes equal to the reference voltage V _r at θ _i , the output terminal of the voltage comparator 38 becomes ungrounded. At this time, if the negative direction signal E _s1 is induced in the signal coil 13 and the transistor 15 is cut off, an ignition signal is sent to the thyristor 3 via the path of the capacitor 61 → resistor 19 → resistor 20 → diode 21 → the gate of the thyristor 3. is given, and the thyristor 3 becomes conductive. This causes capacitor 4
is discharged through the primary coil 2a, and an ignition operation is performed. 5H shows a change in the potential of the output terminal 38c of the voltage comparator 38, and FIG. 5F shows a change in the potential of the collector of the transistor 15.

Here, the charging current of the ignition position control capacitor 31 is i ₁ and the discharging current is i ₂ , and this capacitor 31
Let C be the capacitance of Also, the engine speed is N
(rpm), and the width of θ _b ~ θ _i is α゜, β゜≡
360−θ _w , the maximum value V _dc of the maximum terminal voltage of the capacitor 31 is given by V _dc = (i ₁ /C (1/6N) β゜ ... (1). On the other hand, the transistor 15 is cut off and discharge of the capacitor 31 starts, the terminal voltage V _d of the capacitor 31 is expressed as V _d = V _ep - (i ₂ /C) (1/6N) α゜...(2) Substituting equation (1) into equation (2), V _d = (i ₁ /C) (1/6N) β゜ − (i ₂ /C) (1/6N) α゜ ...(3) ( Calculating α゜ from equation 3), α゜=(i ₁ /f ₂ )β゜−(V _r C/i ₂ )6N...(4) Therefore, the voltage between angle θ _b and θ _a The angle θ _i at which the output terminal 38 c of the comparator 38 becomes ungrounded is θ _i = θ _b − α゜ = θ _b − (i ₁ / i ₂ ) β ゜ + (V _r C / i ₂ ) 6N... ...(5) As is clear from equation (5), the angle θ _i is a function of the rotation speed N, and θ _i advances as the rotation speed increases.
When the engine speed reaches N ₁ , θ _i = θ _b − (i ₁ / i ₂ ) β゜
+(V _r C/i ₂ )6N ₁ ...If the relationship (6) is satisfied, the angle θ _i in equation (5) for higher rotational speeds is the generation interval of the negative direction signal E _{s1 θa}
˜θ _b , the transistor 15 becomes cut off at the angle θ _i , and at this angle θ _i an ignition signal is applied to the thyristor 3 to perform the ignition operation. Since the angle θ _i in equation (5) increases linearly as the rotational speed N increases, the ignition position advances linearly as the rotational speed increases. The number of rotations
When the voltage exceeds _N2 , the charging time of the capacitor 31 becomes shorter and the capacitor 31 is no longer charged to the reference voltage _{Vr or} higher, so the output terminal 38c of the voltage comparator 38 is always in a non-grounded state, and the angle θ
At _b , a negative direction signal e _s is generated and the transistor 15 is cut off, at the same time a firing signal is given to the thyristor 3. Therefore, at a rotation speed of N ₂ or more, the ignition position becomes θ _b (constant). On the other hand, at rotational speeds below N ₁ , the transistor 15 is cut off θ _a
~θ _b The output terminal 38c of the voltage comparator 38
is never ungrounded. Here the angle θ _a
When the positive direction signal E _s2 is induced in the signal coil 13, an ignition signal is given to the thyristor 39 and the thyristor 39 becomes conductive, so that the capacitor 31 shown in FIG. 2 is discharged through the thyristor 39. As a result, the output terminal 38c of the voltage comparator 38 becomes ungrounded, and the signal coil 13 is connected to the diode 1.
An ignition signal is input to the thyristor 3 through the thyristor 2. Since these operations occur instantaneously at an angle θ _a , N ₁
The ignition position at the following rotation speeds is θ _a (-constant).

As mentioned above, according to the embodiment of FIG.
The advance angle characteristic shown in the figure can be obtained, but here, the advance angle slope, the advance angle start rotation speed N ₁ and the advance angle end rotation speed N ₂ are determined by charging current i ₁ , discharging current i ₂ ,
It can be freely selected by appropriately selecting the reference voltage _Vr and the capacitance of the capacitor 31. Moreover, in this case, the detection circuit for detecting N ₁ and N ₂ , etc.
The ignition time can be controlled with high precision without requiring any complicated circuits.

In the above embodiment, since the ignition position determination circuit for starting is provided, which is composed of the thyristor 50, the resistor 51, and the Zener diode 52, the Zener level of the Zener diode 52 is determined by the negative value of the signal coil 13 at the rotational speed at the time of starting. Set rotation speed at which advance angle operation starts when the direction signal level is higher than
By setting the value to a value lower than the negative direction signal level of the signal coil 13 at _N1 , it is possible to prevent the transistor 15 from being cut off when a negative direction signal is induced in the signal coil 13 during startup. Therefore, at startup, the thyristor 3 is activated by the half-cycle output E _s2 generated after the signal coil 13, regardless of the terminal voltage of the capacitor 31.
An ignition signal is given to the ignition signal, and the ignition operation is always performed at the normal ignition position _θ1 .

Note that various modifications can be considered to the ignition position determining circuit for startup. FIG. 6 shows an example of this, in which a capacitor 60 constituting a delay circuit is connected in parallel with the Zener diode 37 shown in FIG. With this configuration, since it takes time for the voltage at the positive input terminal 38a of the voltage comparator 38 to reach the specified value of the reference voltage V _r at the time of startup, the reference voltage at the time of startup can be lowered. Therefore, the position at which the output of the voltage comparator reaches a high level at startup can be delayed to an angle θ _a , and at startup, the ignition operation is always performed at an angle θ _a at which the positive output of the signal coil 13 rises. You can do it like this.

In addition to the above-described circuit, the ignition position determining circuit for starting may be a switch circuit that prevents the reference voltage V _r from being supplied to the voltage comparator 38 until the starting of the engine is completed. For example, in the embodiment of FIG. 4, the resistor 36 and the voltage comparator 3
The object of the present invention can also be achieved by providing a switch circuit between the input terminal 38a of the engine 8 and the input terminal 38a, which becomes conductive when the detected value of the engine rotational speed (rpm) exceeds a set value.

As described above, according to the present invention, the control power supply capacitor is charged to a constant voltage in one half cycle of the exciter coil that charges the ignition energy storage capacitor of the capacitor discharge type ignition circuit, and the control power supply capacitor is Since the ignition position control circuit is operated as follows, there is no need to apply a large current to the exciter coil during the other half cycle of the exciter coil. Therefore, charging of the ignition energy storage capacitor is not delayed due to armature reaction of the exciter coil. In addition, since the control power supply capacitor is charged only after the output of the exciter coil reaches a predetermined value, it does not affect the charging of the ignition energy storage capacitor, and this also prevents the charging of the capacitor from being delayed. As a result, deterioration in ignition performance at high speeds can be prevented.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of the advance angle characteristics required for the engine, Figure 2 is a connection diagram showing the configuration of the ignition position proposed earlier, and Figures 3A and B are the equipment shown in Figure 2. Fig. 4 is a connection diagram showing one embodiment of the present invention, Fig. 5 is a signal waveform diagram of each part of the embodiment shown in Figs. FIG. 3 is a connection diagram showing main parts of the embodiment. 1... Generator coil, 2... Ignition coil, 3...
Thyristor, 4... Diode, 5... Transistor, 6... Diode, 7... Resistor, 8... Spark plug, 10... Ignition position control circuit, 11, 1
4, 17, 19, 20, 34, 35, 36, 4
0,41...Resistance, 12,16,21,28...
Diode, 13... Signal coil, 15, 33...
...transistor, 29,32...constant current circuit, 3
1... Capacitor for ignition position control, 37... Zener diode, 38... Voltage comparator, 39...
Thyristor, 42, 45...Diode, 44...
... Capacitor, 50 ... Thyristor, 51 ... Resistor, 52 ... Zener diode, 60 ... Control power supply circuit, 61 ... Capacitor for control power supply, 63
...First thyristor, 64, 65, 69... Resistor, 66, 68... Zener diode, 67...
...second thyristor, 70...capacitor.

Claims (1)

[Scope of utility model registration request] The main capacitor for storing ignition energy provided on the primary side of the ignition coil, and the output of one half cycle of the exciter coil that induces an alternating current voltage in synchronization with the rotation of the internal combustion engine, set the main capacitor to one polarity. a charging circuit for charging, a discharge control semiconductor switch for discharging the electric charge of the main capacitor through the primary coil of the ignition coil when conductive;
An ignition device for an internal combustion engine, comprising a signal coil that outputs a cycle signal, and an ignition position control circuit that uses the output of the signal coil as a control signal to output a conduction signal for making the semiconductor switch conductive. The position control circuit connects the control power capacitor to a constant voltage using the output of the one half cycle of the exciter coil when the output of the one half cycle of the exciter coil reaches a set value. a constant voltage charging circuit that charges up to 100 volts, an ignition position control capacitor that is charged with a constant current to one polarity through a discharge blocking diode with the charge accumulated in the control power supply capacitor, and one polarity that is generated at the tip of the signal coil. a discharge circuit that discharges the ignition position control capacitor through the discharge range control switch that is conductive for a half cycle; and a reference voltage lower than the maximum charging voltage of the ignition position control capacitor. a reference voltage generation circuit that generates a voltage; and a conduction signal generation circuit that compares the terminal voltage of the ignition position control capacitor with the reference voltage and generates the conduction signal when the terminal voltage becomes equal to or less than the reference voltage. An ignition device for an internal combustion engine, comprising: