JPS626110B2 - - Google Patents

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 power distribution device for an internal combustion engine for suppressing the generation of noise radio waves caused by discharge between a rotor electrode and a side electrode opposite thereto. It is.

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. Furthermore, 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, thereby impeding safe driving of automobiles. For this reason, it is desired to suppress the above-mentioned noise radio waves as much as possible, and various methods have been researched, as described in Japanese Patent Application Laid-Open No. 55-10052, Japanese Patent Application Laid-Open No. 55-40234, etc. being developed.

FIG. 1 is a sectional view of the main parts of a conventional power distributor.
In FIG. 1, a power distributor housing 1 and a camshaft 2 housed therein are attached to an internal combustion engine (not shown). The camshaft 2 is adapted to rotate in conjunction with the crankshaft of an internal combustion engine, and is equipped with a rotor 5 consisting of a rotor electrode 3 and an insulating member 4 to which the rotor electrode 3 is fixed. In addition, the cap 10 of the power distributor has a central terminal 7 fixedly installed in its center, and a plurality of terminals (number corresponding to the number of cylinders) in the circumferential direction.
It is attached to the housing 1 with a side electrode 6 fixed thereon. Further, the center carbon 9 is always urged by a spring 8 in a direction in which it comes into pressure contact with the rotor electrode 3.

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 dielectric breakdown occurs in the air in the discharge gap G between the side electrode 6 and the side electrode 6, the electric power is distributed to the side electrode 6, and then sent to the ignition 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.

However, at the current stage, no power distributor having a sufficient noise prevention effect has been proposed yet.

An object of the present invention is to solve the above-described drawbacks of the prior art and to propose a power distribution device for an internal combustion engine that exhibits a noise prevention effect.

In order to achieve this object, the present invention forms a rotor electrode from a thin plate material, covers the electrode with a material with low thermal conductivity, and makes the wall thickness of the tip of the rotor electrode 1.0 mm or less, and Dimensions of exposed tip part to 2.0
mm or less and is fixed to the rotor body made of an insulating member.

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

FIG. 2 shows an embodiment of the present invention. FIG. 3 shows the - cross section of FIG.

In these figures, the insulating member 4A attached to the camshaft 2 is made of synthetic resin, for example, and is integrally formed with the base 4A ₁ that is fitted onto the camshaft ₂ , and extends in opposite directions from each other. wing section 4 extending to
It consists of A ₂ . Both ends of the wing section _4A2 are formed in an arc shape centered on the center of rotation, and predetermined positions are set on the upper surface of the wing section _4A2 when the rotor electrode 3A and a holding member 11 made of silicone rubber, which will be described later, are assembled. A step part 15 for positioning is formed so that the positioning can be performed, and cylindrical caulking parts 13 are arranged at appropriate intervals.

The rotor electrode 3A is a thin metal plate having a thickness t of 1.0 mm or less, and is made of stainless steel, for example.
This has a substantially T-shape in which one end 3A ₁ is wing-shaped, and the end 3A ₁ forms an arc that matches the arc-shaped edge of the insulating member 4A. Further, the rotor electrode 3A has holes formed at the same pitch as the caulking portions 13 into which the caulking portions 13 are inserted.

One end 1 of the holding member is placed on the upper surface of the wing portion 4A ₂ of the insulating member 4A so as to cover the rotor electrode 3A.
1a is a substantially rectangular plate having an arc shape and the other end being a straight line part in contact with the positioning step, and a center carbon 9 (see FIG. 1) is installed at a position corresponding to the rotation center of the insulating member 4A. A notch 12 that does not come into contact with the insulating member 4A and a circular hole into which the caulked portion 13 of the insulating member 4A is fitted are bored at the same pitch as the caulked portion 13.

The radius of the arc of the end portion 11a shares the center with the wing portion _4A2 of the insulating member and the arcuate edge of the rotor electrode 3A, and is smaller in radius by 2 mm or less. In other words, the amount of protrusion of the rotor electrode 3A is set to 2 mm or less.

The rotor 5A has a caulked portion 13 on the upper surface of the wing portion _4A2 of the insulating member 4A as a guide.
The rotor electrode 3A and the presser member 11 are stacked one on top of the other, and the head of the caulking part 13 is fixed by a known method such as high-frequency heating caulking.

When the rotor 5A is mounted on the camshaft 2 and rotated, it goes without saying that the gap between the tip 3A1 of the rotor electrode _3A and the side electrode 7 (see Fig. 1) becomes a predetermined value. do not have.

Next, the effects of the present invention will be described. The plate thickness of the spark discharge part 3A ₁ , which is the tip of the rotor electrode 3A, is 1.0 mm.
As shown in FIG. 4, the noise current level during spark discharge can be reduced.

Furthermore, since the amount of protrusion of the rotor electrode 3A is set to 2 mm or less, as shown in FIG. 5, the noise current level during spark discharge can be reduced. This is thought to be because the holding member 11 covers the thin rotor electrode 3, which deteriorates heat dissipation from the rotor electrode 3, increases the temperature of the spark discharge section 16, and activates initial electron emission.

Furthermore, when holding member 11 is at 20℃, 0.3cal/cm
If the rotor electrode 3A is formed of a material having a low thermal conductivity of S° C. or lower, the heat dissipation of the rotor electrode 3A will be poor, so the same effect as described above can be achieved.

Furthermore, if the holding member 11 is made of a high-resistance material, a residual charge effect will occur between the conductor portion of the rotor electrode 3 and the holding member 11, and the discharge voltage during spark discharge can be significantly reduced. 1
It is extremely desirable to increase the amount of residual charge by forming the capacitor 1 from a high-resistance material.

In this embodiment, by fixing both sides of the contact portion 14 of the rotor electrode 3 with the center carbon 9 with the holding members 11, deformation due to centrifugal force or heat during operation is prevented. In this embodiment, the notch 12 is made into a round hole, but it does not need to be a round hole; the effect is the same even if the hole is opened on one side, and the number and position of the caulked portions 13 may be arbitrary.

Further, in this embodiment, the caulking portion 13 is connected to the insulating member 4.
Although it is formed integrally with the insulating member 4A, it may be embedded in the insulating member 4A in advance, but this embodiment is superior in terms of productivity and cost.

As explained above, the present invention can sufficiently suppress the generation of noise.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventionally known power distribution section, FIG. 2 is a plan view of the rotor of the present invention, and FIG.
Cross-sectional view, Figure 4 shows the relationship between plate thickness and noise current level,
FIG. 5 is a diagram showing the relationship between the amount of protrusion and the noise current level. 3A... Rotor electrode, 4A... Insulating member, 11... Pressing member, 13... Caulking part.

Claims (1)

[Scope of Claims] 1. A plate-shaped rotor electrode that rotates in conjunction with the rotation of an internal combustion engine, an insulating member that fixedly supports the rotor electrode, and a center carbon that is pressed against the surface of the base end of the rotor electrode. and a side electrode facing the tip of the rotor electrode with a small gap therebetween, in which the upper surface of the rotor electrode is covered with a material having a thermal conductivity of 0.3 cal/cmS°C or less at 20°C. The rotor electrode is sandwiched between the low heat conduction member and the insulating material, and the tip part of the rotor electrode has a thickness of
1.0 mm or less, and a dimension from the tip of the rotor electrode to the tip of the low heat conductive member covering the rotor electrode is 2 mm or less. 2. In the invention as set forth in claim 1, a protrusion that penetrates the rotor electrode and the low heat conduction member and extends to an upper part of the low heat conduction member is formed integrally with the insulating member, and A power distributor for an internal combustion engine, characterized in that a tip is crimped from above the low heat conductive member toward the insulating member.