JPH0115708B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power distribution device for internal combustion engines, and in particular to a power distribution device for internal combustion engines for suppressing the generation of noise radio waves caused by discharge between a rotor electrode and a cap side electrode facing the electrode. The present invention relates to a method for manufacturing a rotor electrode for a power distributor.

Noise radio waves caused by spark discharge in the ignition system of an internal combustion engine such as an automobile may interfere with communications such as television and radio. In addition, it may cause damage to electronic equipment installed in automobiles, such as electronically controlled fuel injection devices, electronic anti-skid devices, and electronically controlled automatic transmissions, which may impede safe driving of automobiles. Therefore, it is desired to suppress the above-mentioned noise radio waves as much as possible, and various methods are being researched and developed.

Conventionally, as shown in FIG. 9a of JP-A No. 55-91768, a rotor electrode is formed by bonding a conductive metal electrode plate formed into an electrode shape and a dielectric plate formed into the same shape with an adhesive. known to be manufactured.

However, in rotor electrodes manufactured by this conventional method, the adhesive did not reach the discharge end side edges of both electrodes, and a gap of 0.2 to 0.4 mm was sometimes created between the two electrodes.

When this void occurs, the original effect of pasting the dielectric material is reduced by half. In particular, since heat dissipates from the voids, there is a problem in that the aim of covering the electrodes with a dielectric material to improve the heat retention of the conductive metal electrode portions and increase thermionic emission is weakened.

In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a method for manufacturing rotor electrodes that can reliably bring a dielectric plate into close contact with the discharge side edge of an adjacent conductive metal electrode plate. do.

The purpose of this is to form a composite plate by bonding the two with adhesive, punch out this composite plate into an electrode shape, and closely fit the punched curved surface of the dielectric plate to the edge of the conductive metal electrode plate. This can be achieved by manufacturing the rotor electrodes by a press punching process.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view of the main parts of a generally known power distributor. In FIG. 1, the power distributor is attached to an internal combustion engine (not shown) together with a camshaft 2 protruding into a housing 1. The camshaft 2 is connected to and rotates with the crankshaft of the internal combustion engine, and the camshaft 2
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 top. In addition, a cap 10 has a central terminal 7 fixed in the center and a plurality of side electrodes 6 (number corresponding to the number of cylinders) fixed in the circumferential direction.
is attached to the housing 1. Further, the center carbon 9 is in contact with the rotor electrode 3 by a spring 8.

In the above configuration, a high voltage from an ignition coil (not shown) is introduced from the center terminal 7 via a high voltage cable (not shown), is transmitted to the rotor electrode 3 via the spring 8 and the center carbon 9, and is transmitted to the tip of the rotor electrode 3. After the air in the discharge gap G between the side electrode 6 and the side electrode 6 is dielectrically broken down and the electricity is distributed to the side electrode 6, it is sent to the spark plug via a high voltage cable (not shown).

In the above operation, the rotor electrode 3 and the side electrode 6
The spark discharge phenomenon during this period is the main source of noise in the ignition system. It is also generally well known that there is a strong correlation between the noise radio waves generated by discharge and the discharge voltage, and that lowering the discharge voltage reduces the amount of noise generated.

FIGS. 2 and 3 show that a gap is intentionally formed at the discharge end of the joint between the conductive metal electrode plate and the dielectric plate.
This is an experiment to see how the air gap affects the discharge voltage characteristics. The width of the gap was equal to the width of the electrode, and the depth was constant at about twice the thickness of the conductive metal plate. Base metal 3 of rotor electrode 3
A is stainless steel with a plate thickness of 0.6 mm, and dielectric 12 is plate thickness
The spacer 11 was a 0.5 mm silicon plate, and the gap h was adjusted using paper.The spacer 11 was assembled into the main body shown in FIG. 1 and measured at a rotational speed of 750 rpm.

As understood from FIG. 3, the gap h between the base metal 3A of the rotor electrode 3 and the dielectric 12 is
It has been found that an excellent effect can be obtained by setting the gap h to 0.2 mm or less, and that the best effect can be obtained by setting the gap h to 0 mm. For this reason, the present invention provides a manufacturing method for obtaining a rotor electrode having a structure in which the gap h between the base metal 3A and the dielectric 12 is extremely small.

FIG. 4 shows a rotor electrode 3 obtained by the present invention.
1 shows a cross section of a rotor 5 having a dielectric material 1.
A rotor electrode 3 having a base metal 3A fixed to the upper part of the rotor electrode 2 is fixed to an insulator 4 by a caulking part 14. The discharge surface of the base metal 3A and the dielectric 12 are in close contact with each other with almost no gap.

Next, the rotor electrode manufacturing method according to the present invention will be explained based on FIG. 5.

A conductive metal plate serving as the base metal 3A (hereinafter referred to as base metal 3A) and a dielectric plate serving as the dielectric 12 (hereinafter referred to as dielectric 12) are pasted together with an adhesive.
It is formed as a composite plate 18. Here, the conductive plate is made of stainless steel, and the dielectric plate is made of glass cloth impregnated with silicone resin.

Next, the composite plate 18 made of the pasted base metal 3A and dielectric 12 is punched into the shape of a rotor electrode using a press punching machine. What is important here is that the dielectric 12 is located on the punching direction side. That is, in FIG.
16 is a male mold, 17 is a female mold, the male mold 16 moves in the direction of the arrow 15, and a composite plate 18 to which the base metal 3A and the dielectric material 12 are pasted.
In this case, the dielectric 12 is located on the female mold 17 side, and the male mold 16
The base metal 3A is located on the side.

Therefore, when the male die 16 moves to the female die 17 side and the composite body 18 is punched out, since the dielectric body 12 is located at the front of the composite plate 18 in the advancing direction, the relationship between the dielectric body 12 and the base electrode 3A is Since the boundary surfaces are in close contact with each other, it is difficult to form a gap between the dielectric 12 and the base metal 3A.

FIG. 6 shows a half-sectional perspective view of the rotor electrode 3 punched by the method shown in FIG.
The dielectric material 1 curves back to the opposite side.
The punched curvature surface 20 that contacts the base metal 3A of No. 2 is also curved toward the base metal 3A side, and thereby the boundary between the base metal 3A and the dielectric 12 is brought into close contact with no gap.

As described above, according to the present invention, it is possible to reliably bring the dielectric material into close contact with the edge of the dielectric plate side of the conductive metal electrode plate. As a result, the discharge pressure of this type of bonded electrode can be reliably lowered, and a power distributor with less noise can be obtained. Further, according to the present invention, there is an advantage that there is no need for any special process for eliminating the gap between the two plates other than the process of forming the rotor electrodes.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main parts of a generally known power distribution device, Figure 2
The figure shows a main cross-section of the dielectric added rotor electrode used in the experiment, Fig. 3 is a characteristic diagram showing the relationship between the gap and discharge voltage, Fig. 4 is a cross-section of the main part of the rotor according to the present invention, and Fig. 5 FIG. 6 is a cross-sectional view showing the electrode forming method. FIG. 6 is a half-sectional perspective view of a rotor electrode made by the method shown in FIG. DESCRIPTION OF SYMBOLS 1... Housing, 2... Camshaft, 3... Rotor electrode, 4... Insulator, 5... Rotor, 6... Side electrode, 7... Center terminal, 8... Spring, 9...
...Center carbon, 10...Cap, G...
Discharge gap, 11... Spacer, 12... Dielectric, 13... Adhesive, 16... Male die, 17... Female die, 19... Punching burr surface.

Claims (1)

[Scope of Claims] 1. A rotor electrode that rotates in conjunction with the rotation of an internal combustion engine, and a plurality of side electrodes that face the rotor electrode through a small gap, and each of the internal combustion engine A method for manufacturing a rotor electrode of a power distributor for an internal combustion engine configured to supply power to a spark plug provided in a cylinder, the rotor electrode being made of a conductive metal electrode plate and a dielectric plate having the same shape as the rotor electrode. In the method of forming the rotor electrode from a composite plate bonded with an adhesive, A: A conductive metal plate and a dielectric plate are pasted together with an adhesive to form a composite plate. B: Punching the composite plate into the shape of the rotor electrode. A method for manufacturing a rotor electrode of a power distributor for an internal combustion engine, characterized in that the rotor electrode is manufactured by a press punching process in which the punched burr surface of the dielectric plate is brought into close contact with the edge of the dielectric plate side of the conductive metal plate.