JPS6137823Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a general-purpose forced air-cooled engine equipped with a non-contact electronically controlled ignition device.

In general, the above-mentioned ignition device consists of an ignition unit made by molding electronic control elements such as transistors, SCRs, diodes, and electrical components such as capacitors and resistors into a plastic carrier, a power generation coil, a voltage boosting coil, etc. be done. However, although this allows the ignition unit, each coil, etc. to be disposed at arbitrary locations, there is a risk of wiring errors between the various members and disconnection of the connecting lead wires.

This idea uses the ignition system components between the power generation coil and the ignition coil output terminal.
Forming the ignition unit as a single ignition unit solves the above problem, and in this case, the ignition unit has a relatively large external shape, so the unit obstructs the flow of cooling air, increases air blow resistance, and causes engine damage. This also solves the problem of deterioration in cooling performance.

Examples of this invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional plan view of essential parts of a general-purpose forced air-cooled engine, and FIG. 2 is a sectional view taken along the line -- in FIG. In the figure, 1 is the crankcase, 2 is the crankshaft,
3 is a centrifugal cooling fan that also serves as a flywheel;
4 is a fan case that covers the outer surface of the cooling fan 3;
is a recoil starter.

A transistor type ignition unit G is attached to a fan case bracket 6 facing a cooling air passage P in the fan case 4. This ignition unit G is integrally formed with a control block 7 fixed with bolts behind the fan case bracket 6, and a power generation block (protrusion) 8 protruding into the cooling air passage P from the front side of the control block 7. Become. Control block 7
is the intermittent circuit 7A among the ignition circuits shown in FIG.
Circuit components such as transistors, diodes, and capacitors constituting the amplifier circuit 7B and the ignition coil 9 are molded into a plastic carrier. Further, as shown in FIG. 2, the power generation block 8 is constructed by molding both power generation coils, a pulsar coil 10 and an exciter coil 11, in a plastic carrier with a small distance in the vertical direction. Moreover, this power generation block 8 has a magnetic steel 12 exposed on the outer surface of the cooling fan 3.
It is formed in a curved shape along the

As shown in FIG. 1, on the inner surface of the cooling fan 3, a power generating coil 13 for a lighting power source and a magnetic steel 14 for exciting the power generating coil 13 are arranged.

In the figure, numeral 15 is a set hole for mounting the ignition unit G, 16 is a spark plug, and 17 is a high voltage cord for connecting the spark plug 16 to the output terminal of the ignition coil.

FIGS. 4A and 4B show another embodiment. In Figure A, the tip of the power generation block 8 of the ignition unit G is connected to the magnetic steel 12.
It differs from the above embodiment in that it is disposed facing the inner end surface of. Further, in this case, only the tips of the core portions 10a and 11a of the pulsar coil 10 and the exciter coil 11 are made to protrude into the power generation block 8.

In addition, in FIG. B, the pulsar coil 10 and the exciter coil 11 are arranged in a stacked state in the front and rear direction,
In response to this, dedicated magnetic steels 12 and 12a are provided individually.

In addition to the above embodiments, it is possible to change the ignition device to a capacitive discharge type, or to supply the primary current from a battery.

Incidentally, the high voltage cord 17 may be molded integrally with the ignition unit G, or may be formed separately.

As explained above, in this invention, the ignition system components from the generator coil to the ignition coil are molded inside the plastic carrier to form the ignition system as one ignition unit, so the ignition system structure is It is possible to eliminate wiring errors between members and disconnections of connecting leads, and it is possible to obtain an ignition device that works reliably and has stable performance. Moreover, since the assembly of the ignition device is completed simply by attaching the ignition unit, the assembly can be carried out easily and at low cost.

Further, in the above-mentioned ignition unit, at least the core portion of the power generating coil projects from the outer surface of the ignition unit, and the above-mentioned ignition unit is arranged in such a state that this projecting portion passes through the fan case bracket and faces the magnetic steel attached to the outer surface of the cooling fan. is fixed behind the fan case bracket to minimize the obstruction of the cooling air flow by the ignition unit.
It is possible to prevent the cooling performance of the engine from deteriorating.

[Brief explanation of drawings]

The drawings show an embodiment of this invention; Fig. 1 is a cross-sectional plan view of the main parts of the engine, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is an ignition circuit diagram, and Fig. 4 A and B are respectively shown. FIG. 2 is a sectional view of a main part corresponding to FIG. 1 showing another embodiment. 3...Cooling fan, 4...Fan case, G...
...Ignition unit, 7...G control block, 8...
...Protrusion (G power generation block), 9...Ignition coil, 10, 11...Generation coil (10
... Pulsar coil, 11 ... Exciter coil), 12 ... Magnetic steel, P ... Cooling air passage, 10
a, 11a... 10, 11 core parts.

Claims (1)

[Scope of utility model registration request] The ignition system components between the generator coils 10 and 11 and the output terminal of the ignition coil 9 are
The ignition unit G is formed by molding in a plastic carrier, and at least the core portions 10a,
11a to form a protruding part 8, and this protruding part 8 passes through the fan case bracket 6 extending from the crankcase, and the outer surface of the centrifugal cooling fan 3 driven by the engine power of the forced air cooling engine. A general-purpose forced air-cooled engine equipped with a non-contact electronically controlled ignition system, characterized in that the ignition unit G is fixed behind a fan case bracket 6 of the engine in a state facing a magnetic steel 12 attached to the engine.