JPS5813108Y2 - internal combustion engine ignition system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an internal combustion engine ignition device, particularly to an improvement in the drive path of an ignition signal generator.

BACKGROUND ART Conventionally, as a method of driving a rotating shaft of an ignition signal generating device, driving is performed from an intermediate shaft driven by an engine via a meshing portion.

Incidentally, the meshing part is provided with a play gap to enable the rotation shaft to be engaged and disengaged, and the angular velocity of the engine fluctuates in relation to the compression and explosion processes, and the rotation Since the shaft has rotational inertia, the ignition signal generation timing, that is, the ignition timing, will fluctuate due to the above-mentioned difference in the free space.
It was not possible to obtain the specified ignition timing accuracy.

This invention provides an excellent internal combustion engine ignition system that eliminates the above-mentioned drawbacks, and an embodiment shown in the drawings will be described below.

In FIG. 1, 1 is a camshaft of an internal combustion engine, 2 is an intermediate shaft having a gear 2a driven by this camshaft, 3 is an oil pump drive shaft driven from this intermediate shaft, and 4 is the above-mentioned intermediate shaft. 2 is an engine case supporting an engine case, 5 is an ignition signal generator having a housing 5a fixed to this case, 5b is a rotating shaft provided concentrically with the intermediate shaft and supported by the housing 5a, and 5C is well known from this rotating shaft. A cam 5e is rotatably attached to the housing 5a by a well-known vacuum mechanism 5f, and an interrupter 6 is opened and closed by the cam 5C to generate an ignition signal.
is a meshing portion consisting of a groove 2b formed at the tip of the intermediate shaft 2 and a protrusion 5g fitted into this groove with a clearance;
The intermediate shaft 2 and the rotating shaft 5b are connected in the rotational direction.

2C is a tapered surface formed on the outer periphery of the shaft end of the intermediate shaft 2 so that the tip end has a small diameter, and 7 is a tapered surface 7a that is attached to the rotating shaft 5b via a pin 8 and joined to the tapered surface 2C. 7b is an engine oil flow hole formed in the guide cylinder to prevent seizure of the tapered surfaces 2c and 7a, 9 is a needle or ball type bearing, and 10 is a hole between this bearing and the housing 5a. It is a compression coil spring that is provided and presses the tapered surface 7a against the tapered surface 2C via the bearing 8 and the guide cylinder 7.

Next, the operation of this embodiment will be explained.

When the engine starts and the camshaft 1 rotates, the gear 2a and the intermediate 2
, the rotating shaft 5b is driven via the meshing portion 6, the cam 5C is rotated via the centrifugal advance mechanism 5d, the interrupter 5e is opened and closed, and an ignition signal is generated.

While the engine is rotating, the rotational angular velocity of the camshaft 1 changes in relation to the compression and explosion processes of the combustion chamber (not shown), and the rotational angular velocity of the camshaft 1 changes.
The opening/closing timing of the interrupter 5e, that is, the ignition timing, tends to change due to the rotational inertia of the groove 2b and the play in the rotational direction between the groove 2b and the protrusion 5g. Since the surface 7a is pressed against the tapered surface 2C of the intermediate shaft 2, relative movement between the intermediate shaft 2 and the rotating shaft 5b is prevented by the frictional force between the tapered surfaces 7a and 2d, and the Fluctuations in ignition timing are prevented.

In the above embodiment, the rotation shaft 5b is biased toward the intermediate shaft 2 by utilizing the axial clearance of the rotation shaft 5b with respect to the housing 5a. The intermediate shaft 2 is
In some cases, it may be more desirable to bias the intermediate shaft 2 toward the rotating shaft 5b since the intermediate shaft 2 is not subject to restrictions on the amount of movement in the axial direction.

This embodiment is shown in FIG. In FIG. 2, 2d is a flange formed on the intermediate shaft 2, and 11.12 is a metal that supports the intermediate shaft 2 on the engine case 4. In this embodiment, the spring 10 is attached to the case 4. Against metal 11. The tapered surface 2C of the intermediate shaft 2 is pressed against the tapered surface 7a of the guide cylinder 7 via the bearing 9 and the flange 2d, and has the same effect as the embodiment in FIG. 1.

In addition, the same effect can be obtained by using a non-contact type signal generator such as a magnet generator type consisting of an inductor, signal coil, and magnet instead of the mechanical signal generator consisting of the cam 5C and the intermittent 5e. It can be played.

Further, in the above embodiment, the guide tube 7 is attached to the rotating shaft and the intermediate shaft 2 has a tapered surface.
On the contrary, it goes without saying that similar effects can be obtained by attaching the guide tube 7 to the intermediate shaft 2 and forming a tapered surface on the rotary shaft.

As described above, this invention provides a tapered surface that is pressed by a spring across the meshing part in a device that is driven by an engine through the meshing part, so that the ignition timing is controlled by the play in the meshing part. This prevents things from becoming unsteady.
Ignition timing accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of this invention, and FIG. 2 is a sectional view showing another embodiment of this invention. In the figure, 2 is an intermediate shaft, 5 is an ignition signal generator, 5e is an interrupter, 6 is a meshing portion, 7 is a guide tube, 2C and 7a are tapered surfaces, and 10 is a spring. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An intermediate shaft driven by an engine, a rotating shaft that is provided concentrically with the intermediate shaft and driven from the intermediate shaft through a meshing part, and a cam cylinder or inductor that rotates from this rotating shaft via a centrifugal advance mechanism. A signal generator that generates an ignition signal, an oil pump drive shaft that is driven from the shaft end of the intermediate shaft, and an outer periphery of the shaft end of the intermediate shaft or rotary shaft having a small diameter at a meshing portion between the intermediate shaft and the rotary shaft. an internal combustion engine comprising: a tapered surface formed as shown in FIG. Ignition device.