JPS6038267Y2 - ignition coil - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an iron core structure of a resin-molded ignition coil.

Regarding the core structure of resin-molded ignition coils, battery ignition coils use an open magnetic path system that uses only a central core, while AC ignition coils use a closed magnetic path system that combines a closed magnetic circuit core with a central core.

In the case of battery ignition coils, the closed magnetic path method is not used because magnetic saturation in the iron core prevents sufficient magnetic energy from being stored, and residual magnetism in the iron core reduces magnetic flux changes when the primary current is cut off. This is to avoid putting it away.

However, such an open magnet system requires a large number of windings to obtain the necessary inductance, which is disadvantageous in terms of cost and temperature rise.

In order to solve the above-mentioned problems, the present invention has the iron core structure of the ignition coil for battery ignition system by using a U-shaped resin spacer between the central iron core and the closed magnetic circuit iron core, and a non-magnetic metal reinforcing washer. The purpose is to obtain an ignition coil for a battery ignition system that has high performance, excellent vibration resistance, and heat resistance by inserting the ignition coil between a resin spacer and a rivet.

The present invention will be described below with reference to embodiments shown in the drawings.

1 to 3, reference numeral 1 indicates the main body of the resin-molded ignition coil, which includes a primary winding (not shown) and 2
A secondary winding is provided.

2 is an I-shaped central core to which the coil body 1 is attached; 3
3a is an end plate at both ends of the U-shaped closed magnetic circuit iron core, and 3b is a mounting hole provided in the closed magnetic circuit iron core 3.

4 is a resin spacer with a U-shaped cross section with a thickness of about 0.57 ML, 5 is a rivet made of non-magnetic material such as brass or aluminum, and 6 is a high voltage cord connected to the secondary winding of the coil body 1. .

7 is a disk-shaped reinforcing washer made of non-magnetic metal such as brass or aluminum.

Here, the central iron core 2 and the closed magnetic circuit iron core 3 are made of laminated iron plates, and the end plates 3a at both ends thereof are also made of a magnetic material such as an iron plate.

The central iron core 2 and the end plates 3a at both ends of the closed magnetic circuit iron core 3 are coupled with non-magnetic rivets 5 via a U-shaped resin spacer 4, with a gap equal to the plate thickness of the spacer 4. It has a magnetic path structure.

Here, a washer 7 is inserted between the resin spacer 4 and the rivet 5.

In the above configuration, the magnetization characteristics of the ignition coil using the closed magnetic circuit core with gears are as shown in the curve shown in Figure 4.
The magnetic energy stored when current flows through the primary winding has an area of 0-B·φb-o.

This area is determined from 0-A・φa・0 in the case of the magnetization characteristic of curve a in FIG. 4 for an open magnetic path, and from curve C in FIG. 4 for a completely closed magnetic path.
It becomes larger than 0・C・φC・0 when the magnetization characteristic is .

Also, since it is equipped with a gear, residual magnetism when the primary current is cut off is extremely small due to the self-demagnetizing force of the gap.

By using the gapped closed magnetic path method as described above, it is possible to obtain an ignition coil with extremely good performance.

As described above, in the present invention, by inserting a resin spacer to create an air gap between the central core and the closed magnetic circuit iron core, it is possible to form an air gap at a predetermined interval without generating eddy currents. This greatly improves the performance of the ignition coil, and since inserting only a resin spacer has poor vibration resistance and heat resistance,
By inserting a reinforcing washer made of non-magnetic metal between the resin spacer and the rivet and fixing the closed magnetic circuit core and the center core with the rivet, the structure has excellent vibration resistance, heat resistance, and ignition resistance. An excellent effect is that an ignition coil with an air gap of good performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view showing one embodiment of the ignition coil of the present invention, FIG. 2 is a right side view of the ignition coil shown in FIG.
FIG. 4 is a cross-sectional view of the main part taken along the line AA' shown in the drawing, and FIG. 4 is a magnetization characteristic diagram of the iron core. 1... Main body of resin molded ignition coil, 2...
...Central core, 3...Closed magnetic circuit core, 4 U-shaped resin spacer, 5...Rivet, 7...
...Non-magnetic metal washer.

Claims (1)

[Scope of utility model registration request] In an ignition coil formed to provide an air gap in the magnetic path of the coil, the air gap is constructed by inserting a resin spacer, which is an electrical insulator, into a rivet fixing part between the closed magnetic circuit core and the center core, and the resin An ignition coil in which a reinforcing non-magnetic metal washer is inserted between the spacer and the rivet.