JPS6031418Y2 - engine ignition system - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of the ignition system for small engines such as chainsaws, etc., and its purpose is to improve the ignition coil of a magnet generator that is driven in synchronization with the engine. To provide a new engine ignition device which allows either a contact type ignition device or a non-contact type ignition device to be installed very simply and easily according to the request of a user.

Figures 1 and 2 show the conventional ignition system for this type of engine. Figure 2 is the first
A sectional view taken along the line ■-■ in the figure is shown.

1 and 2, 1 is the crankshaft of the engine, 2 is the engine body, and on the side of the engine body 2, an iron core 4 wrapped with a power generating film 3 for ignition is fixed with a mounting screw 5. ing.

6 is a magnet rotor, and this magnet rotor 6 includes two magnets 7.8 magnetized in the circumferential direction as shown in the figure, three magnetic pole pieces 9, 10, 11, and a balancer 12. The boss member 13 is integrally formed of a non-magnetic material 14 such as an aluminum alloy.

The boss member 13 is provided with a keyway 13' for determining the mounting position, and a key 15 fixed to the crankshaft 1 of the engine is inserted into this keyway 13', and the taper of the crankshaft 1 is inserted into the keyway 13'. It is fitted and fixed to the portion 1'.

Note that 15' is a tightening nut.

Next, one end of the generating coil 3 is grounded, and the other end is connected to a circuit breaker contact 17, a capacitor 18 for extinguishing contact sparks, an ignition coil 19 consisting of a primary coil 20 and a secondary coil 21, and a spark plug 23. A contact type ignition device 16 consisting of the following is connected.

When the magnet rotor 6 of the magnet generator for engine ignition shown in FIG. 1 and FIG. Magnetic flux changes φ□, φ as shown in Figure 4
2 occurs, voltages v1, 2, and v3 having waveforms as shown in FIG. 4 are induced in the generator coil 3.

Then, due to the impedance of the generating coil 3, a current A is slightly delayed from the waveform position of the types IEv1, v2, and v3.
1, A2, and A3 flow into the generating coil 3.

However, this electric wtA1, n-n, is a contact type ignition device 1.
If the circuit breaker contact 17 of No. 6 is closed, the same contact 17
However, as shown in Figure 4A, the interrupter contact 17 opens approximately 30 degrees before the engine crank angle of 0 degrees (the piston position is at top dead center), so until now the flow has flowed through the contact 17. As shown in the fourth diagram, the current flowing through the ignition coil 19
The current rapidly flows through the primary coil 20 of.

As a result, a high voltage is induced in the secondary coil 21, and a high voltage spark is ignited in the ignition plug 23 to ignite the engine.

As is clear from the above explanation, the magnet generator for engine ignition connected to the contact type ignition device 16 shown in FIGS. The relative positions of the magnet rotor 6 and the generator coil 3 are set so that the peak value of the current A2) shown in is approximately 30 degrees before the engine crank angle of 0 degrees, which is the engine ignition timing. .

Therefore, if a capacitor discharge type non-contact ignition device 24 as shown in FIG. 3 is connected to the engine ignition magnet generator connected to the contact type ignition device 16 shown in FIGS. 1 and 2, the following will occur. There are disadvantages as shown below.

This will be explained below.

In FIG. 3, 24 indicates an example of a capacitor discharge type non-contact ignition device, and this device 24 has a diode 2.
5, 26, 27, a capacitor 28, a semiconductor switching element 29 such as an SCR, an ignition coil 30 consisting of a primary coil 31 and a secondary coil 32, and a spark plug 33.

When this non-contact ignition device 24 is connected to the generating coil 3 of the magnet generator shown in FIGS. 1 and 2, the voltage V2 in one direction of the generating coil 3 shown in FIG.
Since current flows through the circuit of capacitor 28 through capacitor 5, capacitor 28 is charged to the polarity shown.

Next, the voltage v3 in the other direction shown in FIG. , and the cathodes are electrically connected, and the charge charged in the capacitor 28 is rapidly discharged to the primary coil 31 of the ignition coil 30 via the anode and cathode of the semiconductor switching element 29.

Therefore, a high voltage is induced in the secondary coil 32 and a high voltage spark is ignited in the ignition plug 33 to ignite the engine.

The charging/discharging voltage waveform of the capacitor 28 is as shown in FIG. 4, and the capacitor discharging current waveform flowing through the primary coil 31 of the ignition coil 30 is as shown in FIG.

Therefore, as is clear from FIG. 4, when the non-contact ignition device 24 shown in FIG. 3 is connected to the generating coil 3 of the magnet generator shown in FIGS. 1 and 2, the ignition timing of the engine is The ignition system has a fatal disadvantage in that the position is approximately 30 degrees behind the 0 degree crank angle.

However, in recent years, a capacitor discharge type non-contact ignition system as shown in Figure 3 has been added to the magnet generator for engine ignition connected to a contact type ignition system as shown in Figures 1 and 2. There are many users who want to connect a non-contact ignition system, and in this case, conventionally, it was necessary to replace the generator with a magnet generator suitable for the non-contact ignition system shown in Figure 3 each time, which was extremely disadvantageous economically. there were.

The present invention has been developed with attention to the above points, and a simple improvement in which first and second keyways having a predetermined angular difference are provided in the crankshaft fitting part of the magnet rotor enables the magnet generator to be improved. Either a contact type ignition device or a non-contact type ignition device can be connected to the ignition generating coil very simply and easily according to the customer's request.

The embodiment of the present invention shown in FIGS. 5 and 6 will be described below. FIG. 5 shows a contact type ignition device 16 in the ignition power generation coil 3 of a magnet generator, and FIG. 6 shows the ignition power generation coil 3. 3 is connected to the non-contact ignition device 24, and when a contact type ignition device 16 is connected to the boss portion 13 of the magnet rotor 6 of this magnet generator, the tapered portion 1' of the crankshaft 1 A first keyway 13A that fits with the key 15 fixed to the key 113A, and a second keyway 13B that fits the key 15 when the non-contact ignition device 24 is connected are connected to the first keyway 113A. The configuration is exactly the same as the conventional ignition device shown in FIGS. 1 to 3, except that it is installed at a position approximately 60 degrees counterclockwise from the position, and since it is indicated by the same reference numeral, a detailed explanation thereof will be provided. is omitted.

Therefore, the ignition device of the present invention-embodiment is provided in the host member 13 of the magnet rotor 6 when the contact type ignition device 16 is connected to the ignition generating coil 3 of the magnet generator as shown in FIG. Insert the key 15 fixed to the tapered part 1' of the crankshaft 1 into the keyway 13A, and
However, when connecting the non-contact ignition device 24 to the generator coil 3 as shown in Fig. 2, the magnet rotor 6 must be removed and rotated approximately 60 degrees clockwise. ,
When the key 15 is inserted into the second keyway 13B provided in the boss member 13 and is fitted and fixed to the tapered portion 1' of the crankshaft 1, a non-contact ignition device connected to the generating coil 3 is connected. 24 can ignite the engine at the same ignition timing as the contact type ignition device shown in FIG.

As is clear from the above explanation, according to the present invention, there is a magnet rotor that is positioned, fitted and fixed by a single key fixed to the crankshaft of the engine, and a magnet rotor that faces the magnetic poles of the magnet rotor. Either a contact type ignition device, which is equipped with a magnet generator consisting of an ignition generator coil fixed to the main body of the engine, or a capacitor discharge type non-contact ignition device that does not require a signal generator. In an engine ignition system that allows connection of either
First and second keyways having a predetermined angle difference are provided in the crankshaft fitting portion of the magnet rotor, and when the contact type ignition device is connected to the ignition generating coil, the first keyway is provided. When the non-contact ignition device is connected to the ignition generator coil, keys fixed to the crankshaft are fitted and positioned in the second key grooves to fix the magnet rotor. Therefore, it is possible to connect either a contact type ignition system or a non-contact type ignition system according to the user's request without any modification to the engine, and it can also be used like a conventional engine ignition system. Since there is no need to prepare both a magnet generator for contact-type ignition devices and a magnet generator for non-contact ignition devices, mass production is possible, which can significantly reduce manufacturing costs. There are many significant practical effects.

[Brief explanation of drawings]

Figures 1 and 2 are for explaining the conventional ignition system for this type of engine, and Figure 1 is a sectional view taken along line I-I in Figure 2 of a magnet generator to which a contact type ignition system is connected. , second
The figure is a sectional view taken along the line ■-■ in Figure 1, Figure 3 is an electric circuit diagram showing an example of a capacitor discharge type non-contact ignition device that does not require a signal generator, and Figure 4 is a conventional ignition device described above. Fig. 5 and Fig. 6 are cross-sectional views of a magnet generator with an electric circuit showing an ignition device according to an embodiment of the present invention. The figure shows the case where a non-contact ignition device is connected to each of the ignition generator coils. In the figure, 1 is the engine crankshaft, 1' is the tapered part of the crankshaft, 2 is the engine body, 3 is the generator coil, 4 is the iron core, 6 is the magnet rotor, 13 is the boss member, and 13A is the first
13B is a second keyway, 15 is a key, 16 is a contact type ignition device, and 24 is a capacitor discharge type non-contact type ignition device that does not require a signal generator.

Claims (1)

[Scope of utility model registration request] It consists of a magnet rotor that is positioned and fitted by a single key that is fixed to the crankshaft of the engine, and a generator coil for ignition that is fixed to the main body of the engine so as to face the magnetic poles of the magnet rotor. An ignition system for an engine that is equipped with a magnet generator and that allows connection of either a contact type ignition device or a capacitor discharge type non-contact type ignition device that does not require a signal generator to the ignition generator coil, First and second keyways having a predetermined angle difference are provided in the crankshaft fitting portion of the magnet rotor, and when the contact type ignition device is connected to the ignition generating coil, the first keyway is provided. When the non-contact ignition device is connected to the ignition generator coil, keys fixed to the crankshaft are fitted and positioned in the second key grooves to fix the magnet rotor. An engine ignition device characterized by: