JPS603345Y2 - Ignition distributor cap for internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cap for an ignition distributor for an internal combustion engine, particularly a cap in which the center and side electrode conductors extend in a horizontal direction substantially perpendicular to the central axis. This invention relates to an improved structure for improving withstand voltage.

In a general ignition distributor for an internal combustion engine, the center electrode conductor located at the center of the top wall of the cap, and each side electrode conductor located at the periphery, are connected vertically, that is, along the center axis of the cap ( It is arranged in a direction parallel to the axis of rotation of the power distributor.

However, with this structure, the axial length of the ignition power distribution device must be increased, and as a result, the work of installing the ignition power distribution device into the internal combustion engine is often complicated.

In addition, since each electrode conductor is dispersed on the top wall of the cap, connecting high voltage cords to them becomes complicated, and in some cases, it may be difficult to connect high voltage cords to some electrodes due to the presence of other equipment. There is also.

In order to eliminate this problem, it is recommended to extend and embed the center and side electrodes in the top wall of the cap in the radial direction or in a direction parallel to this, that is, in a lateral direction perpendicular to the center axis. desirable.

According to this, it is possible to shorten the axial length of the cap itself, and by extension, shorten the entire ignition distributor, which often facilitates installation into an internal combustion engine.

In addition, it becomes possible to arrange the connection portions of each electrode with the high voltage cord at one or two places, and it is also possible to facilitate the connection of the high voltage cord.

However, when the electrode conductors are arranged in the horizontal direction in this manner, it is impossible to avoid a situation in which adjacent electrode conductors come close to each other, and therefore the insulation between adjacent electrode conductors becomes a problem.

In other words, since high voltage is applied to the electrode conductors, corona discharge occurs in the space between adjacent electrode conductors, and the insulating material that makes up the cap body deteriorates due to corona in this area, and eventually dielectric breakdown occurs and the normal There is a risk of high voltage flashover from one electrode conductor to an adjacent electrode conductor.

In view of the above points, the present invention aims to sufficiently improve the withstand voltage between adjacent electrode conductors with a simple structure in an ignition distributor cap in which the center and side electrode conductors are extended laterally. purpose.

According to the present invention, a plurality of ribs extending along the electric flux line in the space between adjacent electrode conductors are formed integrally with the cap body made of an insulating material, so that most of the electric flux passes through these ribs. done to.

This suppresses the occurrence of corona discharge, thereby effectively achieving the above-mentioned objective.

1 to 3 show an embodiment of the cap according to the present invention.

This cap 1 constitutes an ignition distributor for a four-cylinder internal combustion engine, and is fixed to the housing of the distributor by an appropriate method.

As is well known, a rotating shaft is supported by the housing, and a power distribution rotor that controls high voltage power distribution is attached to this rotating shaft.When the cap 1 is fixed to the housing as described above, the power distribution rotor is not attached to the inside of the housing. to be accommodated.

The above cap 1 is a cap body 2, and this cap body 2
It has a center electrode conductor 3 buried in the cap body 2, and four side electrode conductors 4A to 4D also buried in the cap body 2.

The camp main body 2 is made of an insulating material such as polypropylene or PBT, and is formed into a substantially cup-like shape having a cylindrical side wall 21 and a disc-shaped top wall 22 covering one end thereof.

A cylindrical center electrode tower 23 is provided at the peripheral edge of the top wall 22 of the cap body 2, protruding in the radial direction of the top wall 22, and four similar center electrode towers 24A to 24D are arranged parallel to the radial direction. It is provided so as to protrude in one direction.

Here, the four side electrode towers 24A to 24D are arranged together at a position facing the center electrode tower 23.

Further, on the inner surface of the top wall 22, protrusions 25, 26A to 26D are provided which extend to the respective towers at positions along the buried portions of the center and side electrodes.

Both the center and side electrode conductors are embedded in the top wall 22 of the cap body 2.

The center electrode 3 is located at the center of the top wall 22 at one end so as to be in contact with the above-mentioned power distribution rotor via a brush (not shown), and from here along the protrusion 25 in the radial direction of the top wall 22. The other end is located inside the center electrode tower 23 .

A high voltage cord (none of which is shown) from an ignition coil is attached to this tower 23, and the center electrode conductor 3 is connected to this high voltage cord.

The four side electrode conductors 4A to 4D are positioned at one end at equal intervals around the periphery of the top wall 22 to face the above-mentioned power distribution rotor, and from there, along the respective protrusions 26A to 26D, It is guided to each tower 24A-24D.

Each of the towers 24A to 24D is connected to a high voltage cord (none of which is shown) to a spark plug.

Of these four side electrode conductors, the two conductors 4A and 4B on the center electrode tower side once approach the inside in the radial direction, and then extend in a direction parallel to the center electrode conductor 3 (projection 25). Tower 24A.

You will be led to 24B.

In addition, the remaining two side electrode conductors 4C and 4D are connected to the top wall 2.
2 extending radially outwardly from each tower 24C, 24D.
be led to.

Therefore, each electrode conductor 3, 4A to 4D is located between adjacent protrusions 25, 26A to 26D embedded therein, that is, protrusion 25 and protrusions 26A and 26.
B, between the protrusions 26A and 26C, and between the protrusions 26B
and 26D, there are a plurality of each (four in the illustrated example).
A rib 5 is formed integrally with the cap body 2 made of an insulating material so as to bridge between the protrusions.

Each rib 5 is substantially orthogonal to the extending direction of the corresponding protrusion (electrode conductor), and is therefore provided in a direction along the electric flux line.

Note that when the cap 1 is fixed to the housing of the ignition distributor, the central axis of the cap body 2 coincides with the axis of the rotating shaft of the distributor.

Therefore, the radial direction of the top wall 22 of the cap body 2 and the direction parallel thereto are transverse directions substantially perpendicular to the rotation axis.

According to the cap 1 having the above configuration, each electrode conductor 3.4A~
4B is provided on the top wall 22 of the cap body 2 along its radial direction or in the lateral direction parallel to this, the axial length of the cap 1 can be shortened, and accordingly, the ignition distributor The overall length can also be reduced.

Therefore, the limited installation of the internal combustion engine facilitates the installation of the ignition distributor in the space available.

Additionally, since each tower 23, 24A-24D is oriented in the same lateral direction in conjunction with the horizontal extension of each electrode conductor, it is often easier to connect a high voltage hood to each tower.

In particular, by arranging the side electrode towers 24A to 24D together, the high voltage cord can be connected even more easily.

In such a horizontal arrangement of the electrode conductors, adjacent electrode conductors come close to each other, but the occurrence of corona discharge between adjacent electrode conductors is prevented by the ribs 5 made of an insulating material. Ru.

In other words, since the ribs 5 have a higher dielectric constant than air, most of the electric flux passes through the solid dielectric material forming the ribs 5, and even if the distance between the electrode conductors is small, harmful corona discharge will not occur. controlled.

As is clear from the above description, according to the present invention, it is possible to provide an ignition distributor cap that is small and has sufficient withstand voltage.

[Brief explanation of the drawing]

Fig. 1 is a bottom view showing one embodiment of the cap of the present invention;
FIG. 3 is a cross-sectional view taken along the line ■-■ and a cross-sectional view taken along the line ■-■ of FIG. 1, respectively. 2... Cap body, 21... Side wall,
22...Top wall, 25, 26A-26D...
...Protrusion, 3,4A-4D... Electrode conductor, 5.
...Riff.

Claims (1)

[Claims for Utility Model Registration] A cap body made of a substantially pot-shaped insulating material having a cylindrical side wall and a top wall, a radial direction of the top wall embedded in the cap body, or a direction substantially parallel thereto. and a protrusion formed on the top wall of the cap body along the buried portion of each electrode conductor, and between adjacent protrusions on the top wall of the cap body, a protrusion within the protrusion is provided. An ignition distributor cap for an internal combustion engine, characterized in that a plurality of ribs are provided in a direction substantially perpendicular to an extending direction of an electrode conductor.