JPH0447148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition device for an internal combustion engine having a power distribution rotor incorporating a high-voltage diode.

[Conventional technology]

In conventional devices of this type, a common electrode to which positive and negative high voltages are applied at each ignition timing is connected to a first power distribution electrode and a second power distribution electrode through high voltage diodes of opposite polarity. In addition to having a power distribution rotor, two groups of side electrodes arranged in two large and small pitch circles to face the first and second power distribution electrodes are formed on the cap, and a high voltage of positive polarity is applied to the first power distribution electrode. Power is distributed to the side electrode group of the small pitch circle via the power distribution electrode, and a high voltage of negative polarity is distributed to the side electrode group of the large pitch circle via the second power distribution electrode (for example,
DENSO Technical Report No. 301, published June 1, 1981).

[Problems to be Solved by the Invention] However, in the conventional device described above, the tip of the second power distribution electrode on the outer circumferential side faces the side electrode group of the large pitch circle facing outward, and the second power distribution electrode Since the large pitch circle side electrode group is arranged on the outer circumferential side of the tip of the electrode, it is necessary to arrange the large pitch circle side electrode group between the second power distribution electrode and the inner circumferential surface of the cap. There is a problem in that it requires space and the diameter of the cap increases accordingly.

Therefore, the present invention aims to further reduce the diameter of the cap.

[Means for solving problems]

Therefore, the present invention provides a cap made of an insulator having a center electrode to which positive and negative high voltages are alternately supplied at each ignition timing, and two groups of side electrodes arranged in two large and small pitch circles; a common electrode rotatably electrically connected to the electrode; a first power distribution electrode whose tip faces outwardly facing the electrode group on the side of the small pitch circle; and a first power distribution electrode whose tip is on the side of the large pitch circle. a second power distribution electrode facing inward to the electrode group; and a first power distribution electrode connected between the common electrode and the first power distribution electrode.
and a second high voltage diode connected between the common electrode and the second power distribution electrode with opposite polarity to the first high voltage diode, and a power distribution rotor made of an insulator, Further, the cap is integrally formed with a cylindrical partition wall extending toward the space between the rotational trajectories drawn by the respective tips of the first and second power distribution electrodes on its inner peripheral surface side, and this partition wall To provide an ignition device for an internal combustion engine, in which a group of side electrodes of the small pitch circle is arranged along the inner circumferential surface of the partition wall, and a group of side electrodes of the large pitch circle are arranged along the outer circumferential surface of the partition wall. It is something.

[Effect]

As a result, the side electrode group with a large pitch circle is arranged inside the tip of the second power distribution electrode on the outer circumferential side, thereby reducing the distance between the outer circumferential end of the second power distribution electrode and the inner circumferential surface of the cap. Can be done.

In addition, the small pitch circle side electrode group and the large pitch circle side electrode group can be arranged close to each other by separating the inner peripheral surface side and the outer peripheral surface side by a cylindrical partition wall extending from the cap. , therefore,
The pitch circle diameter of these electrode groups can also be reduced.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings. In Figs. 1 to 4, reference numeral 1 denotes a distributor cap made of an insulator, and a center electrode 2 to which positive and negative high currents are applied at each ignition timing is embedded and fixed in the center of the cap. At the center, two groups of side electrodes 3 and 4 are embedded and fixed, with a total of 6 side electrodes arranged at equal angular intervals, 3 each with 2 large and small pitch circles (applied to a 6-cylinder internal combustion engine). Further, a cylindrical partition wall 1a is formed on the inner surface of the cap 1 along the pitch circle between the second group of side electrodes 3 and 4, and the distance from the center of the second group of side electrodes 3 and 4 is the partition wall. The tip electrode portion 4a of the electrode 4 on each side of the small pitch circle is formed along the inner peripheral surface of the partition wall 1a.
are arranged, and the tip electrode portions 3a of each side electrode 3 of a large pitch circle are arranged along the outer peripheral surface of the partition wall 1a, and the side electrodes 3 and 4 of each group are located at approximately the same axial direction inside the cap 1. The tip electrode portions 3a, 4a exposed at the outer circumferential side and the inner circumferential side are separated by a partition wall 1a. Further, a conductive brush 6 is housed in a cylindrical portion 2a formed inside the cap 1 of the center electrode 2 via a coil spring 5.
being pressed inward.

Reference numeral 7 denotes a distributor housing made of aluminum. A cap 1 is screwed and fixed to the open end of the housing 7 with bolts 8. A shaft 9 rotatably driven by an internal combustion engine is inside the housing 7. is maintained.

Reference numeral 10 denotes a power distribution rotor made of an insulator, which is fixed to the shaft 9 with screws 11 and rotates together with the shaft 9. The power distribution rotor 10 includes a first cylindrical wall 10a surrounding the outer periphery of the cylindrical portion 2a of the center electrode 2, and a second cylindrical wall 10a that has a larger diameter than the first cylindrical wall 10a and is located on the inner peripheral side of the partition wall 1a of the cap 1. a cylindrical wall 10b, a first electrode buried portion 10c extending in the axial direction from a part of the second cylindrical wall 10b toward the inner peripheral position of the tip electrode portion 4a of the side electrode 4 of the small pitch circle; It extends radially from a position shifted in the circumferential direction by approximately 120 degrees with respect to the first electrode buried portion 10c on the bottom side of the cylindrical wall 10b to the outer circumferential side of the partition wall 1a of the cap 1, and then the side electrode 3 of a large pitch circle An L-shaped second electrode buried portion 10 extends in the axial direction toward the outer peripheral position of the tip electrode portion 3a.
d is integrally formed with an insulator.

In addition, the first cylindrical wall 1 at the center of the power distribution rotor 10
A common electrode 12 is fixed to the surface surrounded by 0a, and the brush 6 is in sliding contact with the outer surface of this common electrode 12. And the common electrode 12
A part of the common electrode 12 is embedded in the insulator of the power distribution rotor 10 and extends to an annular storage space 13 surrounded by the first and second cylindrical parts 10a and 10b, and the tip connection part 12a of the common electrode 12 is inserted into the storage space 13. It stands out.

Furthermore, the first electrode buried portion 1 of the power distribution rotor 10
A first power distribution electrode 14 extending in the axial direction is buried in 0c, and the tip electrode portion 1 of this first power distribution electrode 14
4a is exposed from the top of the first electrode embedding portion 10c and faces outwardly from the tip electrode portions 4a of the electrodes 4 on each side of the small pitch circle through a small gap. The other end of the first power distribution electrode 14 is buried in the insulator of the power distribution rotor 10 and extends to the storage space 13, and the tip connection portion 14b of the first power distribution electrode 14 projects into the storage space 13.

A second power distribution electrode 15 extending in an L-shape along the second electrode buried portion 10d of the power distribution rotor 10 is buried, and a tip electrode portion of the second power distribution electrode 15 is embedded in the second electrode buried portion 10d of the power distribution rotor 10. 15a is exposed from the top of the second electrode buried portion 10d and faces inwardly through a small gap with the tip electrode portions 3a of the electrodes 3 on each side of the large pitch circle. Here, the first and second electrode buried portions 1 of the power distribution rotor 10
The axial heights of the top portions 0c and 10d are approximately the same, and the axial heights of the tip electrode portions 14a and 15a of the first and second power distribution electrodes 14 and 15 are also approximately the same. Further, the other end of the second power distribution electrode 15 is buried in the insulator of the power distribution rotor 10 and extends to the storage space 13, and the tip connection portion 15b of the second power distribution electrode 15 projects into the storage space 13.

Reference numeral 16 designates two first high-voltage diodes that are connected in series and housed in the storage space 13.The anode side is connected to the tip connection part 14b of the first power distribution electrode 14 by soldering, and the cathode side is connected to the common electrode 12. It is connected to the tip connecting portion 12a by soldering.

Reference numeral 17 designates two second high-voltage diodes that are connected in series and housed in the storage space 13.The anode side of the second high-voltage diode is connected to the tip connection portion 12a of the common electrode 12 by soldering, and the cathode side is connected to the second power distribution electrode 15. It is connected to the tip connecting portion 15b by soldering. Further, the storage space 13 is filled with an insulating filler 18, and the first and second high voltage diodes 16 and 17 are sealed with the filler 18.

Next, the operation of the above configuration will be explained.
The shaft 9 and the distribution rotor 10 rotate in synchronization with the rotation of the internal combustion engine, and as shown in FIG.
A negative high voltage is supplied to the center electrode 2 at the ignition timing facing one of the tip electrode portions 4a of each side electrode 4 of the small pitch circle of the tip electrode portion 14a of the power distribution electrode 14. As a result, a negative high voltage is supplied to one side electrode 4 of the small pitch circle facing the first power distribution electrode 14 via the common electrode 12, the first high voltage diode 16, and the first power distribution electrode 14. , to generate an ignition spark at a spark plug (not shown) of a specific cylinder.

As the power distribution rotor 10 rotates, as shown in FIG. 4, the tip electrode portion 15a of the second power distribution electrode 15 moves to the tip electrode portion 3a of each side electrode 3 of the large pitch circle.
At the next ignition timing opposite to one of the two, a positive high voltage is supplied to the center electrode 2, thereby causing the common electrode 12, the second high voltage diode 17
and one of the second pitch circles facing this second power distribution electrode 15 via the second power distribution electrode 15.
A negative high voltage is supplied to the two side electrodes 3 to generate an ignition spark in the spark plug (not shown) of the cylinder to be ignited next.

Here, the tip electrode portion 15 of the second power distribution electrode 15
a is facing inward and facing the side electrode 3 of the large pitch circle, and the tip electrode part 1 of the second power distribution electrode 15
Side electrode 3 with a larger pitch circle on the inner circumference side than 5a
is arranged, compared to the conventional arrangement in which a large pitch circle side electrode is arranged on the outer periphery of the second power distribution electrode 15, the outer periphery of the second electrode buried portion 10d of the power distribution rotor 10 and the cap 1 The distance A between the cap 1 and the inner circumferential surface of the cap 1 can be reduced, resulting in a reduction in the diameter of the cap 1.

Furthermore, as the performance of internal combustion engines increases, the required ignition voltage is also increasing, and the high-voltage power distribution section of the distributor is also required to have a high withstand voltage. To ensure withstand voltage, it is necessary to maintain a distance between the regular power distribution section and the ground section. When comparing positive polarity sparks and negative polarity sparks, it is known that positive polarity sparks require more insulation distance, for example.
In order to secure 30KV, approximately 31V is required for negative polarity spark.
mm, the insulation distance for positive polarity spark is approximately 35 mm. In the conventional configuration, since the positive spark power distribution side is configured on the inside, the diameter of the cap 1 has inevitably become large in order to ensure the above-mentioned insulation distance of the power distribution section. In this embodiment, the negative spark distribution side is configured on the inside, so the insulation distance B of the inside power distribution section shown in FIG. can be made smaller,
The cap diameter can be reduced accordingly. FIG. 4 shows the power distribution at the outer electrode in this embodiment, and the insulation distance C of the outer power distribution section at this time is sufficiently larger than the insulation distance B of the inner power distribution section shown in FIG.
Sufficient withstand voltage can be ensured whether a positive polarity spark or a negative polarity spark occurs.

By using the above two points (the inward direction of the tip electrode part 15a of the second power distribution electrode 15 and the inner configuration of the negative spark power distribution side), in a distributor that guarantees a withstand voltage of 30 KV, the cap diameter can be In this example, the conventional φ96mm one is
It became possible to reduce the size to φ82mm.

In the embodiments described above, the positive polarity spark distribution side is placed on the outside, but the effect of diameter reduction due to the reduction of dimension A can be obtained even when the negative polarity spark distribution side is placed on the outside.

〔Effect of the invention〕

As described above, in the present invention, the small pitch circle side electrode group and the large pitch circle side electrode group are separated into the inner peripheral surface side and the outer peripheral surface side by the cylindrical partition wall extending from the cap. Therefore, not only can the pitch circle diameter of these electrode groups be made small, but also the side electrode group with a large pitch circle can be placed inside the tip of the second distribution electrode on the outer circumferential side. This has the excellent effect of reducing the distance between the outer peripheral end of the second power distribution electrode and the inner peripheral surface of the cap, thereby making it possible to further reduce the diameter of the cap.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the device of the present invention, FIG. 2 is a plan view showing the power distribution rotor in the above embodiment, and FIGS. 3 and 4 are two diagrams for explaining the operation of the above embodiment. FIG. 3 is an electrical circuit diagram of the high-voltage power distribution section in an operating state. 1...cap, 1a...cylindrical partition, 2...
...Center electrode, 3...Large pitch circle side electrode, 4...Small pitch circle side electrode, 10...
...Power distribution rotor, 12...Common electrode, 14...First
Power distribution electrode, 15... Second power distribution electrode, 16...
First high voltage diode, 17... second high voltage diode.

Claims (1)

[Scope of Claims] 1. A cap made of an insulator having a center electrode to which positive and negative high voltages are alternately supplied at each ignition timing, and two groups of side electrodes arranged in two large and small pitch circles; a common electrode rotatably electrically connected to the center electrode; a first power distribution electrode having a tip facing outwardly to the side electrode group of the small pitch circle; and a first power distribution electrode having a tip facing outward to the side electrode group of the small pitch circle; a second power distribution electrode facing inwardly to the side electrode group; and a first power distribution electrode connected between the common electrode and the first power distribution electrode.
and a second high voltage diode connected between the common electrode and the second power distribution electrode with opposite polarity to the first high voltage diode, and a power distribution rotor made of an insulator, Further, the cap is integrally formed with a cylindrical partition wall extending toward the space between the rotational trajectories drawn by the respective tips of the first and second power distribution electrodes on its inner peripheral surface side, and this partition wall An ignition device for an internal combustion engine, wherein a group of side electrodes of the small pitch circle is arranged along an inner circumferential surface of the partition wall, and a group of side electrodes of the large pitch circle are arranged along an outer circumferential surface of the partition wall. 2 The cathode side of the first high voltage diode is connected to the common electrode and the anode side is connected to the first power distribution electrode, and this first power distribution electrode serves as a negative power distribution electrode, and the second high voltage diode 2. The ignition device for an internal combustion engine according to claim 1, wherein the anode side of the diode is connected to the common electrode, and the second power distribution electrode is used as the positive power distribution electrode. 3. The first and second power distribution electrodes extend in the axial direction while being encapsulated within the insulator of the power distribution rotor, and their tips are exposed from the insulator at approximately the same axial position and connect to the respective side electrodes. An ignition device for an internal combustion engine according to claim 1 or 2, which faces the group.