JP3435922B2 - Magnet generator for capacitor discharge type internal combustion engine ignition system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet generator used for charging a capacitor of a capacitor discharge type internal combustion engine ignition device.

[0002]

2. Description of the Related Art As is well known, an internal combustion engine ignition device of a capacitor discharge type is provided with an ignition coil, an exciter coil provided in a magnet generator driven by the internal combustion engine, and an primary side of the ignition coil. An ignition energy storage capacitor charged to one polarity through a diode by the output voltage of the exciter coil, and a discharge thyristor conducting at the ignition timing of the engine to discharge the electric charge of the capacitor to the primary coil of the ignition coil are provided. There is.

In this ignition system, an AC voltage is induced in the exciter coil in synchronization with the rotation of the internal combustion engine, and the ignition energy storage capacitor is charged to one polarity in one half cycle of the AC voltage. When the thyristor conducts at the ignition timing, the electric charge of the capacitor is discharged through the primary coil of the ignition coil, which causes a large magnetic flux change in the iron core of the ignition coil. Voltage is induced. Since this high voltage is applied to the spark plug attached to the cylinder of the engine, a spark is generated in the spark plug to ignite the engine.

In the capacitor discharge type ignition device,
The number of turns of the exciter coil is increased enough to make the engine start easier by lowering the engine speed at which the ignition operation is started as much as possible, and inducing a high voltage in the exciter coil when the engine is started. I am trying. Therefore, the output characteristic of the exciter coil is that the output voltage rises as the rotation speed increases from the low speed region to the medium speed region, and the peak value of the output voltage becomes maximum in the medium speed region, and the armature in the high speed region. Due to the reaction, the peak value of the output voltage decreases as the rotation speed increases.

Curve A in FIG. 3 shows the change in the voltage (charging voltage) Vc across the capacitor when the ignition energy storage capacitor is charged by the conventionally used exciter coil of the magnet generator. , In this example 2
The peak value of the induced voltage of the exciter coil becomes maximum around 000 [rpm], and the charging voltage of the capacitor shows the maximum value.

[0006]

In the magnet generator for driving the capacitor discharge type ignition device as described above, it is necessary to increase the number of turns of the exciter coil. The peak value of the induced voltage becomes high. Therefore, as the capacitor and thyristor of the ignition device, it is necessary to use a high withstand voltage that can withstand the peak value of the induced voltage of the exciter coil,
The cost of the igniter was unavoidable.

Further, since the medium speed region of the engine is the region most frequently used, when the peak value of the induced voltage of the exciter coil becomes high in this region, the rated withstand voltage of the elements such as the capacitor and the thyristor forming the ignition device is increased. Since a high voltage close to is applied for a long time and the element is operated for a long time with a small withstand voltage margin, the life of the ignition device may be shortened. In order to have a margin in the withstand voltage of the element, it is desirable to suppress the maximum value of the peak value of the induced voltage of the exciter coil as much as possible within the range that does not hinder the ignition operation.

An object of the present invention is to prevent the induced voltage of the exciter coil at low speed or high speed from being significantly affected,
It is an object of the present invention to provide a magnet generator for a capacitor discharge type internal combustion engine ignition device capable of suppressing the maximum value of the peak value of the induced voltage of the exciter coil to be lower than the conventional value.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a magnet rotor driven by an internal combustion engine, and a stator core having a magnetic pole portion facing the magnetic poles of the magnet rotor, and a condenser of a capacitor discharge type internal combustion engine ignition device. The present invention relates to a magnet generator for a capacitor discharge type internal combustion engine ignition device, which includes a stator formed by winding an exciter coil that generates a voltage for charging the internal combustion engine.

According to the present invention, a magnetic path cross-sectional area adjusting portion consisting of a groove or a hole is provided in at least a part of an exciter magnetic path constituting portion through which a magnetic flux interlinking with the exciter coil of the stator core flows. The cross-sectional area of the exciter magnetic path forming portion is reduced at the cross-sectional area adjusting portion.

As the magnet rotor, a magnet having a permanent magnet attached to the inner periphery of the peripheral wall portion of a rotor yoke formed in a cup shape can be used.

As the stator core, a ring-shaped star core in which a plurality of coil winding parts are radially projected from an annular yoke part and pole pieces are formed at the tips of the coil winding parts is used.
An exciter coil may be wound around one coil winding portion of the annular star iron core. In this case, the magnetic path cross-sectional area adjusting unit may be provided, for example, in the coil winding unit in which the exciter coil is wound, or in the pole piece portion at the tip of the coil winding unit in which the exciter coil is wound. You may do it.

Further, a magnetic path sectional area adjusting portion may be provided in the coil winding portion around which the exciter coil is wound and the yoke portion.

When a magnet rotor having a permanent magnet attached to the inner circumference of the peripheral wall of a rotor yoke formed in a cup shape is used, the stator core has magnetic pole portions facing the magnetic poles of the magnet rotor at both ends. It is also possible to use an I-shaped iron core that the user has. In this case, the magnetic path cross-sectional area adjusting portion may be provided in the portion of the iron core around which the exciter coil is wound.

As described above, the magnetic path cross-sectional area adjusting portion composed of a groove or a hole is provided in at least a part of the magnetic path constituting portion for the exciter in which the magnetic flux interlinking with the exciter coil of the stator core flows, and the magnetic path is formed. When the cross-sectional area of the exciter magnetic path forming portion is reduced in the area where the cross-sectional area adjusting portion is provided,
It became clear that the maximum value of the peak value of the induced voltage of the exciter coil that occurs in the medium speed range can be suppressed lower than before without significantly reducing the induced voltage of the exciter coil at low and high engine speeds. It was

Therefore, according to the present invention, the maximum value of the peak value of the voltage applied from the exciter coil to the circuit parts of the ignition device can be made lower than before, and elements such as capacitors and thyristors constituting the ignition device can be made. It is possible to use an inexpensive one having a lower breakdown voltage than the conventional one.

Further, when using those elements having a withstand voltage equivalent to that of the prior art, it is possible to allow the elements with a sufficient withstand voltage, so that the life of the ignition device can be extended.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which 1 is a 4-pole magnet rotor and 2 is a 4 rotor.
It is a pole stator. The magnet rotor 1 is arranged in a cup-shaped iron rotor yoke 101 and at an inner periphery of the peripheral wall portion 101a of the rotor yoke at 90 degree intervals, and is fixed to the peripheral wall portion 101a by adhesion or the like. It is composed of four arc-shaped permanent magnets 102a to 102d. Magnet 102
The a to 102d are magnetized in the radial direction by alternately changing the polarities so that the S poles and the N poles are alternately arranged in the circumferential direction of the rotor. A boss portion 101b is provided at the center of the bottom wall portion of the rotor yoke 101, and the boss portion is fitted to a crankshaft of an engine (not shown) to attach the rotor 1 to the engine.

The stator 2 has coil winding parts 20 each extending from four sides of an annular yoke part 201 having a substantially square outline.
2a to 202d are radially projected in directions different from each other by 90 degrees, and a stator core 204 is formed of an annular star-shaped iron core in which pole piece portions 203a to 203d are formed at the tip ends of the coil winding portions 202a to 202d, respectively. The stator core 20
4 coil winding portions 202a to 202d, and power generating coils 205a to 205d, respectively.
The stator core 204 is a laminated core formed by laminating a predetermined number of steel plates punched into a predetermined shape.

In the stator 2, the inner peripheral portion of the hole 201a inside the yoke portion 201 of the stator core is used as the spigot portion, and the spigot portion is provided on the stator mounting portion side provided on the crankcase of the engine or the like. By being fitted to the portion, the rotor 1 is positioned concentrically with the rotor 1 and is fixed to the engine by a screw (not shown) screwed into the stator mounting portion through a mounting hole 201b provided in the yoke portion 201. It
In this way, with the stator 2 attached to the engine,
The boss portion 101b of the rotor is arranged in the hole 201a inside the yoke portion 201 of the stator core, and the outer peripheral surfaces (magnetic pole portions) of the pole piece portions 203a to 203d of the stator core 204 are magnetic poles of the magnet rotor 1. Are opposed to each other via a predetermined gap.

In the example shown in FIG. 1, the coil winding section 202.
The power generating coil 205a wound around a is used as the exciter coil EX, and the other power generating coils 205b to 205b.
d is used to drive a lighting load such as a head lamp and a battery charging circuit. The power generating coil 205a forming the exciter coil EX is wound using a conductor having a wire diameter smaller than that of the coil conductors forming the other power generating coils 205b to 205d so as to have a sufficiently larger number of turns than the other power generating coils. There is.

In the illustrated example, the coil winding portion 202a, around which the exciter coil EX is wound, penetrates in the laminating direction of the steel sheets, and is formed of an elongated oval hole in the longitudinal direction of the coil winding portion 202a. The magnetic path cross-sectional area adjusting unit 3 is formed, and the cross-sectional area of the magnetic path through which the magnetic flux interlinking with the exciter coil EX flows is reduced in the portion where the magnetic path cross-sectional area adjusting unit 3 is provided.

A capacitor discharge type internal combustion engine ignition device constructed by using the exciter coil of the above-mentioned magnet generator is
An ignition coil, an ignition energy storage capacitor that is provided on the primary side of the ignition coil and is charged to one polarity by the output of the exciter coil, and discharges the electric charge of the capacitor to the primary coil of the ignition coil when conducting. And a thyristor trigger circuit that supplies a trigger signal to the thyristor at the ignition timing of the engine to bring the thyristor into conduction.

FIG. 2 shows a concrete example of the configuration of a capacitor discharge type internal combustion engine ignition device. In FIG. 2, IG is an ignition system in which one ends of a primary coil w1 and a secondary coil w2 are commonly connected and grounded. A coil, C1 is an ignition energy storage capacitor whose one end is connected to the non-grounded side terminal of the primary coil w1 of the ignition coil IG, and Th is a thyristor whose cathode is connected to the ground side between the other end of the capacitor C1 and ground. Is. One end of the exciter coil EX is grounded, and the other end of the exciter coil EX is connected to the connection point between the capacitor C1 and the thyristor Th through the diode D1. A diode D2 with its anode facing the ground side is connected to both ends of the exciter coil EX, and a diode D3 is connected in antiparallel to both ends of the thyristor Th.

A resistor R1 is connected between the gate and cathode of the thyristor Th, and one end of which is grounded to the pulsar coil Ls.
The other end of is connected to the gate of thyristor Th through diode D4. The pulsar coil Ls is a coil provided on the stator side of a signal generator (not shown) attached to the internal combustion engine. The pulsar coil responds to a change in magnetic flux generated by a reluctor provided on the rotor of the signal generator. Pulse-like signal voltage is induced at the ignition timing of the engine. In this example, the pulser coil Ls and the diode D4
A thyristor trigger circuit is constituted by the resistor R1 and the resistor R1.

The high voltage induced in the secondary coil w2 of the ignition coil IG is applied to the spark plug P attached to the cylinder of the engine.

In the ignition device of FIG. 2, the exciter coil EX is provided in the four-pole magnet generator as shown in FIG. 1, so that it induces an AC voltage of two cycles per revolution of the engine. When the exciter coil EX induces a positive half-cycle voltage in the direction of the solid line arrow in the figure, a current flows in the path of the exciter coil EX → diode D1 → capacitor C1 → primary coil of the ignition coil IG → exciter coil EX to cause the capacitor C1 to flow. The polarities shown in the figure are charged to the peak value of the induced voltage of the exciter coil. The induced voltage of the negative half cycle of the exciter coil EX in the direction of the dashed arrow shown is short-circuited through the diode D2.

When the pulsar coil Ls outputs a pulse signal Vs having a polarity in the direction of the arrow shown at the ignition timing of the engine, a trigger signal is given to the thyristor Th and the thyristor becomes conductive, so that the charge of the ignition energy storage capacitor C1 is charged. It discharges through the thyristor Th and the primary coil w1 of the ignition coil IG. As a result, a large magnetic flux change occurs in the iron core of the ignition coil, and a high voltage for ignition is induced in the secondary coil w2. Since this high voltage is applied to the spark plug P attached to the cylinder of the engine, a spark is generated in the spark plug and the engine is ignited. When the capacitor C1 is discharged through the thyristor Th, the capacitor C1 is charged in a polarity opposite to that shown in the drawing, and the charge of the capacitor is discharged through the primary coil of the ignition coil and the diode D3. By providing the diode D3 in this way, the discharge duration of the capacitor can be lengthened and the duration of the spark can be lengthened, but this diode D3 is not always necessary.

By using the exciter coil EX provided in the magnet generator shown in FIG. 1 in the ignition device shown in FIG. 2, the change of the charging voltage Vc of the ignition energy storage capacitor C1 with respect to the rotational speed N [rpm] is changed. As a result of the measurement, the result as shown by the curve B in FIG. 3 was obtained. On the other hand, when the exciter coil of the conventional magnet generator of the same rating in which the magnetic path cross-sectional area adjusting unit 3 is not provided in the coil winding unit 202a is used,
The characteristic of the charging voltage Vc of the ignition energy storage capacitor C1 with respect to the rotation speed N [rpm] is as shown by the curve A in FIG. From the curves a and b in FIG. 3, a magnetic path cross-sectional area adjusting unit 3 is provided in a part of a magnetic path in which magnetic flux interlinking with the exciter coil flows, as in the present invention, and the magnetic path cross-sectional area adjusting unit 2 is It was clarified that the peak value of the induced voltage of the exciter coil generated in the medium speed region can be suppressed by reducing the cross-sectional area of the magnetic path in the provided portion. Moreover, in this case, it was confirmed that the peak value of the voltage induced in the exciter coil at the time of starting the engine and at the high speed was almost the same as the conventional value, and that the ignition performance at the time of starting and the high speed was not hindered.

In the example of FIG. 1, the magnetic path cross-section area adjusting unit 3 is constituted by an oval hole provided by penetrating the coil winding section 202a for winding the exciter coil. No. 3 is not limited to the example shown in FIG. 1, as long as it is provided so as to reduce the cross-sectional area of a part of the exciter magnetic path constituting portion where the magnetic flux interlinking with the exciter coil flows. For example, as shown in FIG. 4, the exciter coil E
The pole piece 2 at the tip of the coil winding portion 202a around which X is wound
It is also possible that the elliptical or elliptical hole is formed by penetrating 03a in the stacking direction of the steel plates, and this hole is used as the magnetic path cross-sectional area adjusting portion 3.

Further, as shown in FIG. 5, the coil winding portion 202a and the coil winding portion 202a around which the exciter coil EX is wound and the pole piece portion 203a at the tip of the coil winding portion are crossed over. It is also possible to form a T-shaped hole penetrating the pole piece portion 203a in the laminating direction of the steel sheets and use this hole as the magnetic path cross-sectional area adjusting portion 3.

Further, as shown in FIG. 6, an inverted T-shaped hole penetrating in the laminating direction of the steel sheets is provided across the coil winding portion 202a and the yoke portion 201, and the inverted T-shaped hole is formed. May be used as the magnetic path cross-sectional area adjusting unit 3.

In the above example, the annular star iron core 204 is used as the stator core, but as shown in FIG. 7, the I-shaped stator core having the magnetic pole portions 4a and 4b facing the magnetic poles of the rotor. The present invention can also be applied to the case where the exciter coil EX is wound around the body of the iron core 4 by using the No. 4 coil. In this case, an oval hole (the shape of the hole is arbitrary) extending along the longitudinal direction is provided in the body of the iron core around which the exciter coil EX is wound, and the hole is used as the magnetic path cross-sectional area adjusting section 3. Good.

The stator shown in FIG. 7 is attached to a stator base plate provided in a case of the engine by bolts inserted into attachment holes 4c provided at both ends of the iron core 4, and magnetic poles at both ends of the iron core 4 are attached. The parts 4a, 4b are opposed to the magnetic poles of a magnet rotor similar to that shown in FIG.

In the above example, the magnetic path cross-sectional area adjusting portion 3 is constituted by the hole penetrating the iron core in the stacking direction, but by providing the punched hole only in a part of the steel plate constituting the iron core,
It is also possible to form a groove that does not penetrate the iron core and use the groove as the magnetic path cross-sectional area adjusting portion 3. In this case, as shown in FIG. 8, a groove forming the magnetic path cross-sectional area adjusting portion 3 may be provided inside the iron core so that the groove is not opened to the outside.

The dimensions of the holes and grooves forming the magnetic path cross-sectional area adjusting section 3 effectively suppress the peak value of the induced voltage of the exciter coil in the medium speed region, and induce the exciter coil at the time of starting and at the time of high speed. It is determined experimentally so that the voltage does not drop significantly.

In the example shown in FIG. 2, the thyristor trigger circuit is configured to give a trigger signal directly to the thyristor Th at the output of the pulsar coil Ls, but based on the engine rotation angle information obtained from the pulsar coil Ls. A thyristor trigger circuit may be used in which the ignition timing is calculated by a microcomputer or the like and a trigger signal is supplied to the thyristor Th at the calculated ignition timing.

In the above example, the magnet generator has four poles, but in the present invention, the number of poles of the magnet generator is arbitrary.

[0039]

As described above, according to the present invention, the magnetic path cross-sectional area adjustment consisting of a groove or a hole in at least a part of the exciter magnetic path constituting portion through which the magnetic flux interlinking with the exciter coil of the stator core flows. By reducing the cross-sectional area of the exciter magnetic path constituent part at the part where the magnetic path cross-sectional area adjusting part is provided, the induced voltage of the exciter coil at a low speed or a high speed of the engine can be significantly reduced. It is possible to suppress the maximum value of the peak value of the induced voltage of the exciter coil generated in the medium speed region to a lower value than in the conventional case, without lowering the maximum value.

Therefore, according to the present invention, the maximum value of the peak value of the voltage applied from the exciter coil to the element of the ignition device is made lower than that of the prior art, so that the ignition device can be used as an element such as a capacitor or a thyristor. Also, an inexpensive one having a low breakdown voltage can be used. In addition, when using those elements that have a withstand voltage equivalent to conventional ones,
Since there is a margin in the breakdown voltage of the element, there is an advantage that the life of the ignition device can be extended.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a capacitor discharge type internal combustion engine ignition device to which the magneto generator of the present invention is applied.

FIG. 3 is a diagram showing the measurement results of the characteristics of changes in the charging voltage of the capacitor of the ignition device with respect to the rotation speed when using the conventional magneto-generator and when using the magneto-generator according to the present invention. is there.

FIG. 4 is a front view of a main portion showing an example in which a magnetic path cross-sectional area adjusting portion is provided in a pole piece portion of a stator core in the embodiment of the present invention.

FIG. 5 is a front view of a main part showing an example in which the magnetic path cross-sectional area adjusting part is provided in the coil winding part and the pole piece part of the stator core in the embodiment of the present invention.

FIG. 6 is a front view of a main portion showing an example in which the magnetic path cross-sectional area adjusting portion is provided in the coil winding portion and the yoke portion of the stator core in the embodiment of the present invention.

FIG. 7 is a sectional view showing an embodiment of the present invention when an I-shaped iron core is used as a stator iron core.

FIG. 8 is a cross-sectional view of a main part showing an example in which a groove forming a magnetic path cross-sectional area adjusting part is provided in the iron core in the embodiment of the present invention.

[Explanation of symbols]

1 magnet rotor 101 rotor yoke 102a-102d Permanent magnet 2 stator 201 Yoke 202a to 202d coil winding section 203a-203d pole piece part 204 Stator core 205a-205d generator coil EX Exciter coil 3 Magnetic path cross-sectional area adjustment unit

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Claims (5)

(57) [Claims] 1. A voltage for charging a capacitor of a capacitor discharge type internal combustion engine ignition device is generated in a stator core having a magnet rotor driven by an internal combustion engine and a magnetic pole portion facing a magnetic pole of the magnet rotor. In a magneto-generator for a capacitor discharge type internal combustion engine ignition device, comprising: a stator formed by winding an exciter coil, wherein at least an exciter magnetic path constituent portion in which a magnetic flux interlinking with the exciter coil of the stator core flows. A magnetic path cross-sectional area adjusting part consisting of a groove or a hole is provided in part, and the cross-sectional area of the exciter magnetic path constituting part is reduced at the part where the magnetic path cross-sectional area adjusting part is provided. Capacitor discharge type magnet generator for internal combustion engine ignition device. 2. The magnet rotor comprises a rotor yoke formed in a cup shape and a permanent magnet attached to the inner circumference of a peripheral wall portion of the rotor yoke, wherein the stator core comprises a ring yoke portion and a plurality of coils. It consists of an annular star-shaped iron core having a pole piece portion formed at the tip of each coil winding portion by radially projecting the winding portion, and the exciter coil is wound around one coil winding portion of the iron core, The magnetic path cross-sectional area adjusting section is provided at least in a coil winding section around which the exciter coil is wound.
A magnetic generator for a capacitor discharge type internal combustion engine ignition device according to claim 1. 3. The magnet rotor comprises a rotor yoke formed in a cup shape and a permanent magnet attached to the inner periphery of a peripheral wall portion of the rotor yoke, wherein the stator core comprises an annular yoke portion and a plurality of coils. It consists of an annular star-shaped iron core having a pole piece portion formed at the tip of each coil winding portion by radially projecting the winding portion, and the exciter coil is wound around one coil winding portion of the iron core, The magnet generator for a capacitor discharge type internal combustion engine ignition device according to claim 1, wherein the magnetic path cross-sectional area adjusting unit is provided at least at a pole piece portion at a tip of a coil winding unit around which the exciter coil is wound. 4. The magnet rotor comprises a rotor yoke formed into a cup shape and a permanent magnet attached to the inner circumference of a peripheral wall portion of the rotor yoke, wherein the stator core comprises a ring yoke portion and a plurality of coils. It consists of an annular star-shaped iron core having a pole piece portion formed at the tip of each coil winding portion by radially projecting the winding portion, and the exciter coil is wound around one coil winding portion of the iron core, The magnet generator for a capacitor discharge type internal combustion engine ignition device according to claim 1, wherein the magnetic path cross-sectional area adjusting unit is provided in a coil winding unit around which the exciter coil is wound and the yoke unit. 5. The magnet rotor comprises a rotor yoke formed in a cup shape with a permanent magnet attached to the inner circumference of a peripheral wall portion thereof, and the stator core faces a magnetic pole of the magnet rotor. The capacitor discharge internal combustion engine according to claim 1, comprising an I-shaped iron core having magnetic pole portions at both ends, and the magnetic path cross-sectional area adjusting portion is provided in a portion of the iron core on which the exciter coil is wound. Magnet generator for ignition device.