JPS6315475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric spark ignition type ignition power distribution device for an internal combustion engine, and in particular, to an electric spark ignition type ignition power distribution device for use in an internal combustion engine, and in particular, to easily suppress the generation of noise radio waves caused by discharge between a rotor electrode and a side electrode that face each other at a predetermined period. Moreover, it can be suppressed stably.

The ignition system for an electric spark ignition internal combustion engine, such as an automobile internal combustion engine, includes an ignition coil, an ignition distributor,
It has an ignition plug, etc., and a large current with a steep rise time flows when a spark discharges in the ignition distributor or the ignition plug. There is a risk that radio noise caused by this spark discharge may interfere with communications such as television and radio, and in some countries, laws regulate radio noise generated from this type of vehicle. .

In addition, this type of noise radio waves not only affect communications, but also affect electronic devices installed in automobiles, such as electronically controlled fuel injection devices, electronic anti-skid devices, and electronically controlled automatic transmissions. There is also a risk that this may impede safe driving.

For this reason, there is a demand for reducing the noise radio waves generated from spark ignition devices, and various devices and devices have been researched and developed or put into practical use.

FIG. 1 shows an example of a conventional ignition power distribution device used in a spark ignition device, where 1 is a housing, and the housing 1 is connected to an internal combustion engine (not shown) together with a camshaft 2 housed inside the housing. ). The camshaft 2 rotates in conjunction with the crankshaft of the internal combustion engine and drives the rotor 3. Rotor 3
consists of an insulating member 4 connected to the camshaft 2, and a rotor electrode 5 made of brass or the like fixed to the upper surface of the insulating member 4.
have. Reference numeral 6 denotes a cap attached to the housing 1, which has a central terminal 7 at its center and side electrodes 8 at its periphery in a number corresponding to the number of cylinders of the internal combustion engine. A center carbon 10 is connected between the center terminal 7 and the rotor electrode 5 via a spring 9.
The center carbon 10 is always in pressure contact with the rotor electrode 5 by the spring 9.

In the ignition distributor configured in this way, high voltage generated in the ignition coil (not shown) is supplied to the central terminal 7 via a high voltage cable (not shown). This high voltage is guided to the rotor electrode 5 via the spring 9 and the center carbon 10, and each time the rotor electrode 5 and the side electrode 8 face each other, the high voltage introduced to the rotor electrode 5 is introduced to the rotor electrode 5. A high voltage is distributed to the side electrode 8 by causing dielectric breakdown of the air in the discharge gap G between the tip 11 and the side electrode 8.
High voltage is then supplied to the spark plug via a high voltage cable (not shown).

The spark discharge phenomenon between the rotor electrode 5 and the side electrode 8 will be described in further detail. That is, the high voltage supplied from the ignition coil does not reach its maximum value in steps, but increases with a time constant determined by circuit constants of the ignition coil, high voltage cable, etc.
Then, when the high voltage value rises to a value sufficient to cause a spark discharge in the discharge gap G, dielectric breakdown occurs in the air in the discharge gap G, causing a spark discharge.

In this case, when the high voltage reaches the above-mentioned value, rapid dielectric breakdown occurs, and the discharge current flows rapidly with a short pulse width and is an unstable current with a high peak value. A large amount of components are generated, which are radiated to the outside using high-voltage cables as antennas and become radio noise.

It is generally believed that the noise electric field radiated from the noise source due to this seed spark discharge is proportional to the noise current. Therefore, in order to suppress the noise radio waves, it is necessary to reduce the capacitive discharge current flowing through the discharge gap between the rotor electrode and the side electrode. Note that the capacitive discharge current here refers to the charge accumulated in the stray capacitance between the electrode, etc. near the discharge gap and the ground, which flows at high speed (about a few nanoseconds) and with a sudden rise at the time of dielectric breakdown. say.

Therefore, in order to suppress the generation of noise radio waves in the ignition distributor, the measures described in (A) to (C) below have been proposed.

(A) A resistor is provided in the rotor electrode This is a resistor embedded in the rotor electrode 5 between the center carbon 10 and the tip 11 of the rotor electrode 5.

(B) Larger discharge gap This is a larger discharge gap G between the rotor electrode 5 and the side electrode 8. For example, the conventional discharge gap G is about 0.75 mm, but it is 1.524 to 6.35 mm.
It is based on the degree.

(C) A third electrode arranged near the rotor electrode The third electrode is attached to the rotor electrode 5 through a dielectric, and when the rotor electrode 5 approaches the side electrode 8, the third electrode and the side A spark discharge is caused between the electrode 8 and the rotor electrode 5 due to the pioneer discharge.
The electric discharge is caused between the side electrode 8 and the side electrode 8.

However, the conventional proposals (A) to (C) each have the following drawbacks.

Regarding (A), due to the stray capacitance in parallel with the resistor, the noise suppression effect on high frequency bands of about 300 MHz or higher is small, and the ignition energy loss due to the resistor (several kilohms to tens of kilohms) is large.

Regarding (B), the noise prevention effect (the effect of reducing the noise electric field compared to the reference noise electric field strength) is excellent at 10 dB or more, but the ignition energy loss becomes extremely large.
Therefore, there is a risk that reliable ignition, which is essential for exhaust purification and improved fuel efficiency in recent years, may be impaired. Furthermore, if a higher voltage than conventional ones is used to ensure ignition, it becomes difficult to take measures against high voltage leaks.

Regarding (C), the structure is complicated and there are problems with long-term reliability.

Therefore, the applicant confirmed the following through various experiments. That is, in an ignition distributor for an internal combustion engine, if a dielectric plate is disposed on at least one of the upper and lower surfaces of at least the discharging tip of the rotor electrode to which high voltage is applied, the rotor electrode and the side electrodes It was confirmed that the generation of radio noise caused by discharge during operation was reduced.

However, if the rotor electrode and the dielectric plate are simply overlapped and attached to the insulating member 4 by caulking or other means, the rotor electrode and the dielectric plate will be separated from each other in areas away from the caulked portion, resulting in a large gap. Because of this, the noise prevention effect obtained was unstable.

An object of the present invention is to have a rotor electrode part having 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 with a small gap in between, and to generate electricity from an ignition coil. In an ignition distributor for an internal combustion engine configured to supply and distribute the high voltage generated between the rotor electrode and the side electrode to the spark plug connected to the side electrode, the Based on cloth,
A rotor electrode portion was formed by punching a rotor electrode material plate obtained by adhering a conductive material formed by impregnating, applying, or spraying silicon varnish onto a base and curing it to at least one surface of a stainless steel plate. An object of the present invention is to provide an ignition power distribution device for an internal combustion engine.

The present invention will be explained in detail below based on the drawings.

FIG. 2 shows an embodiment of the rotor used in the ignition distributor of the present invention, where 21 is a rotor electrode, and at least the tip of the rotor electrode 21 has a thickness of 0.1 to 1.0 mm. A stainless steel plate, a metal material with low thermal conductivity, is used. Note that the rotor electrode 21 may be made uniformly thin, but if the thickness is less than 0.1 mm, wear due to discharge will be significant, resulting in poor durability and impractical.
It was confirmed through experiments that if the thickness exceeds 1.0 mm, the desired noise prevention effect cannot be obtained. Reference numeral 22 denotes a dielectric plate, and the dielectric plate 22 has a base (for example, a lattice-shaped base) made of cloth, knitted glass fiber, resin fiber, etc., and this base is impregnated, coated, or sprayed with silicone resin such as silicone varnish. A silicone resin plate that has been cured after being oxidized can be used. Further, an alumina ceramic substrate or a Teflon plate can also be used. Such a dielectric material has excellent heat resistance, arc resistance, and corona resistance, and is suitable for covering the top or bottom surface of the tip of the rotor electrode 21 where spark discharge occurs.
Also, compared to other resins, it has a greater noise prevention effect due to a reduction in discharge voltage. Reference numeral 23 denotes an adhesive for bonding the rotor electrode 21 and the dielectric plate 22, and a thermosetting and heat-resistant adhesive such as epoxy resin can be used. The rotor electrode 21 and the dielectric plate 22 bonded together with the adhesive 23 form a single rotor electrode part 24, which is placed on the insulating member 4 forming the rotor 3, and this rotor electrode part 24 is It is fixed to the insulating member 4 by caulking using the caulking projections 25 .

In this way, the rotor electrode 21 and the dielectric plate 22
It has been confirmed through experiments that if the rotor electrode section 24 is formed by bonding the two together using an adhesive, the noise generated in the power distributor can be constantly and stably prevented. That is, by using the adhesive 23, a uniform minute gap equal to the thickness of the adhesive 23 is formed between the rotor electrode 21 and the dielectric plate 22 at the tip discharge portion of the rotor electrode 21, and furthermore, the rotor Since the electrode 21 and the dielectric plate 22 are uniformly joined and are not separated from each other, the rotor electrode 2
1 and the dielectric plate 22, and the rotor electrodes and the dielectric plate are simply caulked between the insulating member 4 and the dielectric plate 22, resulting in a more stable noise prevention effect. It was confirmed through experiments that this could be obtained.

3A, B, C and D show the manufacturing process of the rotor electrode section 30 of the ignition distributor of the present invention. As mentioned above, in order to form a uniform bonding surface of the adhesive 23 between the rotor electrode 21 and the dielectric plate 22 and obtain a stable noise prevention effect, first the rotor electrode is bonded as shown in FIG. 3A. A rotor electrode material plate 34 is obtained by bonding the raw metal plate 31 of 21 and the raw material plate 32 of the dielectric plate 22 with an adhesive 33 to obtain a plurality of rotor electrode parts 30 as shown in FIG. 3B. form. Next, from the dielectric material plate 32 side of the material plate 34 obtained in this way, for example, a punching press 35
The molded rotor electrode portion 30 is punched out using a method such as the following. In this way, since the punching process is performed from the side of the dielectric material plate 32, which is softer than the material metal plate 31, burrs and the like are less likely to be formed on the edges of the rotor electrode 21. Figure 3C shows the rotor electrode section 3 punched out in this way.
Indicates 0. Rotor electrode part 3 formed in this way
0, the rotor electrode 21 forming the discharge part
The end surfaces of the tip portions and dielectric plate 22 can be precisely aligned and molded. If the end faces of the rotor electrode 21 and the dielectric plate 22 are aligned without unevenness at the tip where discharge occurs, the dielectric plate 22 is effective in reducing the discharge voltage of the discharge part, which leads to a reduction in the capacitive discharge current. Therefore, the effect of reducing radio noise can be exhibited.
36 is a caulking hole for caulking the rotor electrode portion 30 to the insulating member 4, and in the case of punching, this hole 36 can also be punched out at the same time. Figure 3D
The rotor electrode part 30 molded into the rotor electrode 21
It shows the state where it is caulked to the insulating member 4 with the side facing upward,
37 indicates a caulking portion.

In the above explanation, an example of the rotor electrode section 30 in which the dielectric plate 22 is bonded to the lower surface side of the rotor electrode 21 with the adhesive 33 has been described.
It is also possible to form a rotor electrode portion by adhering these to both surfaces of the rotor electrode 21.

The manufacturing process of the rotor electrode part 40 in which the dielectric plate 22 is provided so as to clamp the rotor electrode 21 is explained in the fourth example.
Illustrated by figures A, B and C. In FIG. 4A, the raw metal plate 31 of the rotor electrode 21 and the raw material plate 32 of the lower dielectric plate 22 are laminated using an adhesive 33 in the same manner as shown in FIG. 3A. 41
is a raw material plate of the upper dielectric plate 42, and 43 is a punch line of the rotor electrode portion 40 drawn on the upper surface of the raw material plate 41. 44 is a center carbon 10 attached to the power distributor cap 6 so that the rotor electrode 21 of the rotor electrode section 40 is attached to the center carbon 10 as shown in FIG. 4C.
This is a punched hole that is punched out in advance in the material plate 41 using a press or the like so that there is no problem in making electrical contact with the material plate 41. After applying the adhesive 33 to the back surface of the upper dielectric material plate 41 in which the punched holes 44 have been punched out in advance, first apply the adhesive 33 to the lower surface of the lower dielectric material plate 3.
The rotor electrode material plate 45 shown in FIG. 4B is obtained by stacking and bonding the rotor electrode material plate 31 on top of the rotor electrode material plate 31 layered with the rotor electrode material plate 2. Therefore, the rotor electrode portion 40 can be obtained by punching out the raw material plate 45 using a punching press along the punch lines 43 of the raw material plate 41 in the same manner as in the above-described example. In addition, in FIG. 4A, 46 is a caulking hole. FIG. 4C shows a state where the rotor electrode section 40 is attached to the insulating member 4 of the rotor 3 by caulking, and 47 is the caulking member.

Note that, as the above-mentioned adhesive, an alkylene resin type, silicone rubber, acrylic resin type, phenolic resin type, etc. can also be used.

As explained above, according to the present invention, the dielectric plate is a silicone resin plate formed by impregnating, applying or spraying silicone varnish onto the substrate, and hardening the silicone varnish. The rotor electrode part was formed by punching out the rotor electrode material plate obtained by adhering at least one side of the stainless steel plate, so that a uniform bonded surface was maintained, resulting in stable radio waves without variations. Not only can a noise effect be obtained, but the discharge part can be obtained with the end surfaces of the rotor electrode and the dielectric plate on the same plane, so the noise prevention effect can be further enhanced. Since there is no protrusion, the performance of the rotor electrodes can be prevented from being impaired.

It has been confirmed through experiments that the above-mentioned effects are more pronounced when the rotor side is set at a negative potential and the side electrode side is set at a positive potential.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the configuration of a conventional ignition distributor, FIG. 2 is a cross-sectional view showing an example of the rotor configuration of the ignition distributor according to the present invention, and FIG. 3A is a molded rotor electrode part. FIG. 3B is a perspective view showing the process of laminating a rotor electrode material plate and a dielectric material plate with adhesive in the manufacturing process, and FIG. , FIG. 3C is a perspective view of the rotor electrode section, FIG. 3D is a perspective view showing the rotor electrode section attached to the rotor, and FIG. 4A is a perspective view of the rotor electrode section of the ignition distributor according to the present invention. FIG. 4B is a perspective view showing another configuration example in the lamination process, FIG. 4B is a perspective view showing the configuration of the laminated plate, and FIG. 4C is a part of the ignition distributor of the present invention using the rotor electrode part. FIG. DESCRIPTION OF SYMBOLS 1... Housing, 2... Camshaft, 3... Rotor, 4... Insulating member, 5... Rotor electrode, 6...
Cap, 7...center terminal, 8...side electrode, 9...
... Spring, 10 ... Center carbon, 11 ... Tip, G ... Gap, 21 ... Rotor electrode, 2
2... Dielectric plate, 23... Adhesive, 24, 30,
40... Rotor electrode part, 25... Caulking projection, 3
1, 32, 34, 41, 45...Material board, 33...
...Adhesive, 35...Punching press, 36,46
... Caulking hole, 37, 47 ... Caulking protrusion, 43
...Punching line, 44...Punching hole.

Claims (1)

[Claims] 1. It has a rotor electrode part having a rotor electrode that rotates in conjunction with the rotation of the internal combustion engine, and a plurality of side electrodes that face the rotor electrode through a small gap, and is capable of transmitting high voltage generated from an ignition coil. , an ignition distributor for an internal combustion engine configured to supply and distribute power to a spark plug connected to the side electrode via discharge between the rotor electrode and the side electrode, which is made of glass or resin-based fibrous material; Based on cloth,
From the side of the dielectric adhered to at least one side of a rotor electrode material plate obtained by adhering a dielectric formed by impregnating, applying or spraying silicon varnish to the base and curing it to at least one side of a stainless steel plate. An ignition power distribution device for an internal combustion engine, characterized in that the rotor electrode portion is formed by punching.