DE2245194A1 - IGNITION COIL - Google Patents

Description

PATENT LAWYERS DipL-Ing. WERNER COHAUSZ Dipl.-Ing. WILHELM FLORACK. Dipl-Ing. RUDOLF KNAUF

4 Düsseldorf, Schumannstrasse 97

Joseph Lucas (_ .; lectrica, l) Limited · ■ - ■ ■

Great King Street

Birmingham, England, September 13, 1972

ignition coil

The invention relates to an ignition coil for an internal combustion engine and its ignition system, and it is based on the object of an ignition coil to be provided in a form suitable for use in connection with fault diagnostic equipment.

An ignition coil according to the invention is characterized by a hollesee Housing which is closed at one end by an insulating cap on which the high voltage output connection of the coil is seated, a conductive core within the housing which is electrically connected to the high voltage terminal, an insulating support member, that engages at one end of the core, primary and secondary windings, surrounding the core with one end of the secondary winding electrically connected to the core, a conductive member spaced from the core with the interposition of the insulating support member, the conductive member forming a capacitor with the core, the insulation of which is the Material of the support member is, and a connection · on the cap of the Ignition coil, which is electrically connected to the conductive member, such that the terminal and the high voltage output terminal the terminals of the capacitor. "

In a preferred manner, the conductive member is a metal plate, which is connected between the support member and a closed end of the housing opposite the cap.

Conveniently, the housing is conductive and the conductive member is isolated from it, said member and housing form a second capacitor.

26 545

Wa / W. . ,

109 B 1 Ί / O Hi

The invention is based on an example of the invention below explained in more detail with reference to the drawing. In the drawing are:

Fig. 1 is a schematic representation in partial section, showing an ignition coil shows, and

Fig. 2 is a circuit diagram illustrating the manner and manner in which the coil can be used in a diagnostic system.

According to Fig. 1, the ignition coil has a hollow cylindrical metal housing 11, which is closed at one end by a one-piece base 12, while the other end is made of synthetic resin shaped cap 13 is closed. The open end of the housing 11 is crimped to encompass the cap 13. The cap 13 wears a high voltage output terminal 14 along with the two usual ones Low voltage connections (not shown). In addition, the further connection 15 sits on the cap, which has a power supply 16 is connected to a metal plate 17 which sits on the floor 12. The plate 17 is arranged at a distance from the floor 12, and by interposing an insulating washer 18 and a hollow one insulating support member 19 ', which is formed from glass, holds the plate 17 to the pane 18 firmly.

A conductive one extends between the support part 19 and the cap 13 Veicheisenkern 21, which at one end in the cap 13 and on the other end is received in the support member 19 and is connected to the high voltage terminal 13 at one end. The core 21 extends through a tubular paper template onto which the secondary and primary windings of the ignition coil are wound. In the usual manner, one end of the secondary winding is 22a, 22b electrically connected to the core 21, while the other end of the secondary winding and one end of the primary winding are electrically connected to one of the two terminals on the cap 13 are connected, the other end of the primary winding to the other of the terminals on the cap 13 is connected.

D-jf core 21 and diu plate 17 are through the bottom area of the glass

10 0 8 12/0941 " ⁵ "

support member 19 spaced from each other, held, and the core 21 and the plate 17 form a capacitor 2J (Fig. 2), its insulation the glass bottom of the gliead 19 is. The high voltage terminal 14 forms one connection of this capacitor, while connection 15 on the cap 13 forms the other terminal of the capacitor.

The support member 19 can be made of materials other than glass be, provided that they have the desired -Isolation- and Have dielectric properties. Phenolic resins have been used and are suitable for certain applications, even if their dielectric constants are stronger with temperature than glass changes.

The inner surface of the housing of the ignition coil is in the usual way with a paper sleeve is provided, which is an inner iron sleeve from the housing separates. The housing is filled with oil in the usual way.

The reason for providing the capacitor 2J in the ignition coil is best explained with reference to Pig. 2 understandable in the. the secondary winding 22a of the ignition coil is shown, the ends of which are connected in the manner described above to the high-voltage terminal 14 and to the terminal B of the ignition coil, the terminal E being connected to ground via a low-impedance path. The coil produces an alternating current output with a voltage on the order of JO.000 YoIt, and when the vehicle fitted with the coil is to be tested using automatic diagnostic equipment by which various parts of the vehicle are examined for faults, this voltage must be stepped, and this can be easily done by providing two capacitors 2J- and 24 in series parallel to winding 22a and a voltage from the connection between 'the capacitors £ ;.' and 2Λ is removed. Typical values for the capacitors 2 ^ and? / J are 5 pf and 5000 pf, respectively, which leads to a voltage between the connection between the capacitors and the terminal E of 20%. The described arrangement is

^Ö 4 -812/0941 - ¹

224519A

it is when connecting to the junction between the capacitors

23 and 24 around the terminal 15 »with the capacitor 23 inside of the coil through the core 21, the plate 17 and the support member 19 is formed. The capacitor 24 is a separate one Capacitor between terminal 15 and terminal £ is switched outside the CuIe, but it should be noted that, because the housing 11 of the igule is at ground potential, the plate 17 and the bottom 12 a capacitor in parallel with the capacitor

24 form, so that the capacitance of the capacitor 24 is selected accordingly, it must be remembered that on the total capacitance must be taken into account, which is required between the connections E and 15.

Claims

309 8 1 2/0941

Claims (3)

Claims 1.J ignition coil for an ignition system of an internal combustion engine, characterized by a hollow housing (11) which is closed at one end by an insulating cap (13) on which the high-voltage output connection (14) of the coil sits, a conductive core (21 ) within the housing (11), which is electrically connected to the high-voltage connection (14), an insulating piece member (19) which engages one end of the core (21), primary and secondary windings surrounding the core (21), wherein one end of the secondary winding is electrically connected to the core (21), a conductive member (17) spaced from the core (21) with the interposition of the insulating support member (19), wherein the conductive member (I7) is connected to the core (21) a capacitor (23), the insulation of which is the material of the support member (19), and a connection on the cap of the ignition coil, which is electrically connected to the conductive member (I7), such that the connection (15) and the high voltage connection (14) the connections d it form capacitor (23). 2. Ignition coil according to claim 1, characterized in that the conductive Member (17) is a metal plate that is opposed between the support member (19) and a closed end (12) of the housing (11) the cap (I3) is switched. 3. Ignition coil according to claim 1 or 2, characterized} that the Housing (11) is conductive and the conductive member (17) is insulated from it, said member (I7) and the housing (11) form a second capacitor (24). 309812/0941 Blank page