JPS5917271B2 - Internal combustion engine ignition signal generator - Google Patents

Description

[Detailed description of the invention] The present invention relates to an ignition signal generating device for an internal combustion engine.

In recent years, there has been a demand for improved ignition timing accuracy in order to dilute the air-fuel mixture and reduce fuel consumption, and in particular, it is necessary to keep the ignition timing difference between each cylinder within 0.5 degrees in a multi-cylinder engine. requested.

By the way, in conventional ignition distributors, the rotating shaft extends from its bearing part to the signal generator operating part such as a cam or inductor, so manufacturing errors in the rotating shaft and the signal generator operating part may cause The signal generator operating section swings in the radial direction, creating a large ignition timing difference between each cylinder.

For this reason, expensive precision machining is applied to the sliding surfaces between the rotating shaft and the signal generator operating part, but this still reduces the ignition timing difference between each cylinder by 1. 5
It is extremely difficult to even keep it within limits.

The present invention provides an internal combustion engine ignition signal generating device that can satisfy the above requirements even if the above precision machining is abolished.

Embodiment 1 shown in the figures will be explained below.

That is, in the figure, 1 is a rotating shaft driven by a multi-cylinder engine (not shown), 2 is a housing that supports this rotating shaft, and 3 is a rotating shaft that is driven by a multi-cylinder engine (not shown).
3a is a camshaft provided on the same axis as the rotary shaft 1 and separated from the rotary shaft 1 in the axial direction, and is driven from the rotary shaft 1 via a well-known centrifugal advance mechanism 4; 3a is a cylinder formed on this camshaft; A cam having cam ridges corresponding to the number of cams, 4a is a base fitted on the rotating shaft 1, 4b is a pin planted on this base, 4c is a vana weight loosely fitted on this pin, and the rotating shaft Due to the centrifugal force it receives as it rotates, it flies against the force of a spring (not shown).

4d is a pin on which this Bana weight is planted, and 4e is a guide elongated hole 4f that is engaged with this pin.
It is an arm fitted into the
The camshaft 3 is advanced with respect to the rotating shaft 1 as d jumps.

Reference numeral 5 denotes a rotary plate supported by the housing 2 via a ball bearing 6, which is rotated around the camshaft 3 in accordance with the intake negative pressure of the engine by a well-known vacuum advance mechanism (not shown). .

I is a ball bearing between the camshaft 3 and the rotary plate 5 (interposed therein), and 8 is an interrupter mounted on the rotary plate 5 and operated by the cam 3a.

Next, the operation of the embodiment configured as described above will be explained.

When the engine starts and the rotary shaft 1 rotates, the camshaft 3 rotates via the centrifugal advance mechanism 4, and the interrupter 8 is driven by the cam 3a to generate an ignition signal.

When the rotational speed of the engine increases, the camshaft 3 is advanced relative to the rotating shaft 1 by the action of the centrifugal advance mechanism 4, and the operating timing of the interrupter 8, that is, the ignition timing is advanced.

Further, when the intake negative pressure of the engine increases, the vacuum advance mechanism rotates the rotary plate 5 in the counter-rotation direction of the rotary shaft 1, thereby advancing the ignition timing.

During the above operation, since the camshaft 3 is supported by the housing 2 via the bearing 7, rotating plate 5, and bearing 6, the radial deflection of the camshaft 3 is almost eliminated.
Ignition timing accuracy is greatly improved, and the difference in ignition timing between cylinders becomes extremely small.

In addition, the ball bearing 7 reduces the sliding torque of the camshaft 3, reduces advance hysteresis, and improves ignition timing accuracy.

Note that the same effect can be obtained even if the camshaft 3 is used as another signal generator operating shaft, such as an inductor shaft, and the interrupter 8 is used as another ignition signal generator, such as a magnetic pickup.

It goes without saying that a cam type governor can be used as the centrifugal advance mechanism 4.

As described above, in the present invention, the signal generator operating shaft is axially separated from the rotating shaft and supported by the housing via a bearing, so that vibrations and deflections of the rotating shaft in conventional devices are avoided. This improves ignition timing accuracy and reduces the difference in ignition timing between cylinders.In addition, it is possible to improve ignition timing accuracy and reduce the difference in ignition timing between cylinders. It has the effect of abolishing the

[Brief explanation of the drawing]

The figure is a sectional view showing an embodiment of the present invention. In the figure, 1 is the rotating shaft, 2 is the housing, 3 is the camshaft, and 3a
is a cam, 4 is a centrifugal advance mechanism, 5 is a rotating plate, 6.1 is a ball bearing, and 8 is an interrupter.

Claims (1)

[Claims] 1. A rotating shaft driven by an engine, a housing that supports this rotating shaft, and a signal provided on the same axis as the rotating shaft and separated in the axial direction and driven from the rotating shaft via a centrifugal advance mechanism. An internal combustion engine ignition signal generating device comprising a generator operating shaft, a bearing for supporting the signal generator operating shaft in the housing, and an ignition signal generator operated by the signal generator operating shaft to generate an ignition signal.