JPS5818560A - Distributor for internal-combustion engine - Google Patents

Abstract

PURPOSE:To decrease discharge voltage and suppress generation of a radio noise caused from a discharge, by forming discharge electrodes with side electrodes and a rotor electrode, providing a dielectric to one side of the rotor electorode and forming notched parts in the vicinity of a spark discharge part of the rotor electrode. CONSTITUTION:A distributor is mounted to an engine together with a cam shaft 2, inserted into a housing 1, and a rotor 5, consisting of a rotor electrode 3 and an insulator 4, is mounted to the cam shaft 2. While a cap 10, fixedly provided with side electrodes 6 and center terminal 7, is mounted to the housing 1. Then a center carbon 9, connecting the rotor electrode 3 to the center terminal 7, is adapted to the rotor electrode 3 by a spring 8. A dielectric 12, consisting of silicon system plate material, is secured to said rotor electrode 3 of stainless or the like by the method of calking, while a plurality of notched parts 15 are formed to an end of the dielectric 12. In this way, surface area of the dielectric 12 in the vicinity of an electric discharge part is increased, and a space charge effect is increased to decrease discharge voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power distribution device for an internal combustion engine, and more particularly to a technique for suppressing the generation of noise radio waves caused by discharge between a rotor electrode and a cap side electrode facing the rotor electrode. .

Generally, in internal combustion engines for automobiles, noise radio waves caused by spark discharge in the ignition system are a problem because they may interfere with communications such as televisions and radios.

Furthermore, in recent years there has been an increase in the number of automobiles equipped with electronic devices (such as fallen tree trunks, electronically controlled fuel injection devices, electronically controlled automatic transmissions, etc.), and the above-mentioned noise radio waves can also interfere with these electronic devices. This may impede safe driving.

For this reason, various efforts have been made to suppress the above noise radio waves as much as possible, and among them, some measures have been taken to prevent noise from power distributors having discharge electrodes similar to spark plugs.

This will be briefly explained based on the drawings.

FIG. 1 is a sectional view of a generally known power distributor, and according to this figure, the power distributor is attached to an engine (not shown) together with a camshaft 2 inserted into a housing 1. As shown in FIG.

The camshaft 2 is connected to the engine crankshaft to rotate.
Then, a rotor 5 consisting of a rotor electrode 3 and an insulator 4 to which the rotor electrode 3 is fixed is mounted.

On the other hand, a central terminal 7f is fixedly installed in the center and a plurality of terminals (
A cap 10 having fixed side electrodes 6 (number corresponding to the number of cylinders) is attached to the housing 1.

Then, it is brought into contact with the top of the rotor electrode 3 that connects the center terminal 7 and the rotor electrode 3.

Therefore, the high voltage generated by intermittent primary current flowing through the ignition coil (shown in the drawing) is introduced into the center terminal 7 of the power distributor via the high voltage cable (not shown), and from there the spring 8 and the center card 9 are connected. The electric current is transmitted to the rotor electrode 3 via a high-voltage cable (not shown) through a complete air dielectric breakdown in the minute discharge gap G between the tip of the rotor electrode 3 and the side electrode 6, and then distributed to the side electrode 6 via a high-voltage cable (not shown). The fuel is then supplied to the spark plugs installed in each cylinder of the engine.

Incidentally, the above-mentioned spark discharge phenomenon between the rotor electrode 3 and the side electrodes 6 in such a power distributor is a main noise source in the ignition system.

Therefore, as shown in Figure 2, the noise radio waves generated by the discharge described above have a strong correlation with the discharge voltage.
Focusing on the fact that lowering the discharge voltage reduces the amount of noise generated, a dielectric 12tl made of a silicon-based material is attached to the rotor electrode 3, thereby lowering the discharge voltage. ing.

Furthermore, in this method, since there is a large variation in the effect of simply adding the dielectric 12, we conducted various experiments to investigate the causes of this, and investigated the gap between the dielectric 12 and the rotor electrode 3. It was determined that the gap formed by the discharge voltage has a large causal relationship with the drop in discharge voltage.

According to this, as shown in Figure 3, the best effect is obtained by setting the gap to 0.2■ or less, and the best effect is obtained by setting it to O, and the larger the gap, the better the effect. It was found that it became thinner.

This discharge experiment was conducted with the structure shown in FIG. 2, and the rotor electrode 3 was made of stainless steel 0.6111+1. A 0.5 m silicon plate is used as the dielectric 12, and a paper spacer 1 is used.
3 to adjust the gap, and install it into the main body of the power distributor shown in Fig. 1.) IJ computer rotation speed: 75 Or
Measured under pm conditions.

As a result, it was finally decided to lower the discharge voltage as much as possible by directly attaching the dielectric material 12 to the rotor electrode 3 by caulking or the like, as shown in FIG. In addition, 14 in FIG. 4 is a caulking part.

The present invention has been proposed in view of the above-mentioned prior art, and includes forming a plurality of cut portions near the spark discharge phenomenon located at the tip of the above-mentioned rotor electrode and the dielectric material attached thereto. In other words, the purpose is to more reliably lower the discharge voltage and prevent noise in the power distributor.

Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 5, the feature of the present invention is that a dielectric material 12 made of a silicon-based plate having the same external shape is fixed to the upper surface of the rotor electrode 3 made of stainless steel or the like by caulking or the like. The point is that a plurality of cut portions 15 are formed at the tip of the rotor electrode 3 (which becomes a spark discharge portion together with the tip of the rotor electrode 3).

This incision 15 is formed in a triangular shape when viewed from above in FIG. 5, but as shown in FIG. It may be formed in a K shape (FIG. 6 (case B)).

The rest of the configuration is the same as that in FIG. 1, so a detailed explanation will be omitted here with reference to FIG.

Therefore, according to the present invention, as described above, the rotor electrode 3
When a spark discharge occurs between the side electrode 6 and the side electrode 6, there is a discharge voltage reduction effect due to the addition of the dielectric 12, and a reduction effect due to the formation of the recessed portion 15 at the distal end of the dielectric 12. Coupled with the effect of promoting a reduction in discharge voltage, a significant reduction in discharge voltage can be obtained.

By forming the cutout portion 15, the surface area of the dielectric 12 near the discharge portion increases, and the discharge voltage can be lowered by enhancing the space charge effect.

Further, by providing the notched portion 15, an edge is formed on the discharge portion (discharge surface) and electric field concentration is promoted, so that the above-mentioned space charge effect can be enhanced. The space charge effect is a phenomenon in which when a dielectric material is provided near the discharge area, ions are charged onto the dielectric material, and when the dielectric breakdown occurs during the discharge, these ions cause a triggering action and reduce the discharge voltage. .

As a result, the discharge voltage is significantly reduced as shown in the table below, and the noise prevention effect of the power distributor can be achieved as described above.

As can be seen in the above table, it has been found through experiments that the above-mentioned effects are noticeable when a silicon glass plate in which glass cloth is impregnated with a silicon face and thermally cured is used as the dielectric 12.

Also, according to experiments, it is better to use a metal with low thermal conductivity such as stainless steel or nichrome as the rotor electrode 3, and to make the thickness as thin as possible, considering that it is practical. It was confirmed that a length of II to 1 m is optimal.

Next, FIG. 7 shows another embodiment of the present invention.

This is done by overlapping the rotor electrode 3 and the dielectric 12, and then integrally forming the notch 15 in the distal end discharge portion of both.
This is intended to further reduce the discharge voltage by ensuring that the two are in contact with each other. Furthermore, this embodiment shows an example in which the dielectric 12 is attached to the lower surface of the rotor electrode 3.

As explained above, according to the present invention, a plurality of notches are formed in the vicinity of the spark discharge portion located at the tip of the rotor electrode and the dielectric attached thereto. Therefore, the effect of reducing the discharge voltage can be reliably obtained, and the effect of providing an excellent power distributor with less noise generation can be obtained.

[Brief explanation of the drawing]

1, 2, and 4 are sectional views of the main parts of each conventional example, and FIG. 3 is an explanatory diagram showing the correlation between the gap and the discharge voltage.
FIG. 5 is a perspective view of the main part of this invention, FIG. FIG. 3... Rotor electrode, G... Gap, 6... Side electrode, 1... Housing, 10... Cap, 12
...Dielectric material, 15... Cut portion. Patent applicant: Nissan Motor Co., Ltd. Hitachi, Ltd.

Claims (1)

[Claims] 1. A discharge electrode is formed by a rotor electrode that rotates in conjunction with the rotation of the engine, and a plurality of side electrodes that face the rotor electrode through a small gap, and In a power distributor for an internal combustion engine configured to distribute and supply high voltage from the electrodes to the spark plugs provided in each cylinder of the engine, a dielectric material is provided on the rotor for energization, the electrodes, and at least one of the upper and lower surfaces thereof. What is claimed is: 1. A power distribution device for an internal combustion engine, characterized in that a plurality of cut portions are formed near the spark discharge portion located at the tips of the cut portions. 2. The power distributor for an internal combustion engine according to claim 1, wherein the cut portion is made of only a dielectric IcI. 3. The power distribution device for an internal combustion engine according to claim 1, wherein the cut portion is integrally formed in both the rotor electrode and the dielectric material fixed to the rotor electrode by caulking or the like. 4. The power distribution device for an internal combustion engine according to any one of claims 1 to 3, wherein the dielectric is a silicon glass plate impregnated with a silicon FET glass cloth and thermally cured. . 5. Claim 1 in which a metal material with low thermal conductivity such as stainless steel or nichrome is used as the rotor electrode.
The power distribution device for an internal combustion engine according to any one of Items to Items 4. 6. The power distributor for an internal combustion engine according to any one of claims 1 to 5, wherein the rotor electrode has a thickness of 0.1 to 1 cm.