AU594158B2

AU594158B2 - Ignition coil for ignition systems of internal-combustion engines

Info

Publication number: AU594158B2
Application number: AU73478/87A
Authority: AU
Inventors: Jose Luis Alemendro; Jose Luis Zurdo
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1986-06-13
Filing date: 1987-05-28
Publication date: 1990-03-01
Anticipated expiration: 2007-05-28
Also published as: DE3619984A1; JPS62299009A; DE3619984C2; AU7347887A

Description

594458 Australia Form PATENTS ACT 1952 COMPLETE SPECIFICATION (ORiGINAL) FOR OFFICE USE Short Title: Int. CI: Applicaton Number- Lodged: 7 ~L72 4 7 I~h vlentC~l, is, the EtWflledJ1nts miade under- Si'cto 49 and is correct for priing. rc o Pnmplete Specification-Locdged: Accepted: 0 Lapsed; Published: Priority: V000 Related Art, 0000 V

~II

Name of Applicant: Address of Applicant: Actual Inventor: TO BE COMPLETED ROBERT BOSCH GMBH BY APPLICANT Postfach 50, 7000 Stuttgart It West Germany JOSE LUIS ALEMENDRO and JOSE LUIS ZURDO Address for Service: CAI 1 LINAN AND ASSO)CIATES, Patent Attorneys, of 48-50 Bridge Road, Richmond, State of Victoria, Australia.

Complete Specification for the invention entitled: "IGNITION COIL FOR IGNITION SYSTEMS OF INTERNAL-COMBUSTION ENGINES" t The following statement is a full description of this invention, including the best method of performing it known to me:- Note:, The description Is to be typed Its double spacing, pica type face, In an area not exceeding 250 mm In depth and 160 mm in width, on tough white paper of good quality and It Is to be inserted Inside this form.

r d i i I 0 o 0 The invention relates to an ignition coil for ignition systems of internal-combustion engines.

An ignition coil is known, for example, from German Patent Application P 34 33 065.8, in which the means for dis,;ipating the heat of the core to the atmosphere is an outer lamella made of aluminium, which is joined together with other core lamellae and which has a flange projecting beyond the latter for iastening to the vehicle body. The heat is consequently also transferred to the vehicle body.

However, the heat dissipation of the known ignition coil is insuffino 10 cient at increased coil power and results in disruptions in the internalcombustion engine.

According to the present invention there is provided an ignition coil for ignition systems of internal-combustion engines, said ignition coil including a multiple-leg closed core of magnetizable material, one leg of which is surrounded by a primary winding and a coaxial secondary winding, and S with an insulating compound which surrounds said one leg and the windings 0 0 and with means for conducting heat away from the core, the thermal conductivity of said means being greater than that of the core, wherein said means is a housing with a sleeve which encloses and contacts said one leg of the core, and in that the sleeve is connected to a jacket by way of a floor to form e4 an annular trough, and said annular trough is filled with said insulating compound, in particular casting resin.

The problem presented in the prior art is alleviated in the present invention by technically simple means which achieves sufficient heat disipation and consequently prevents disruptions in the internal-combustion engine, 4.

4.

44 4.

4.

a- B -2riw

L

p- 1^

V

Ii 0 *0 0 00 0 00 00 0 The idea on which the invention is based is to increase the surface of the heat-dissipating means considerably, whilst at the same time ensuring as small a volume, that is to say space required as poss ble.

A preferred embodiment of the invention is illustrated in the drawing and explained in detail in the following description. The drawings show, in an enlarged representation in each case, the ignition coil for ignition systems of internal-combustion engines, with the dosed iron core, in a predominantly diagonal section, along the sectional line I-I in Figure 2, and, in Figure 2, the housing with the iron core, but without the ignition coil and without a ;0 sealing compound, along the sectional line II-II in Figure 1.

An ignition coil for ignition systems of internal-combustion engines S in Figures 1 and 2 has a housing 10 which is made of aluminium and which has essentially the form of an annular trough. The housing 10 has a sleeve 11 of square cross-section, a jacket 12 concentric relative to this and a bottom 13 .5 connecting the sleeve 11 and the jacket 12. The sleeve 11, the bottom 13 and S the jacket 12 are separated by a radial gap 14, 15, 16, the gap 15, 16 bridging a web 17, 18 of U-shaped cross-section which is removed after the ignition coil has been assembled. On the one hand several heat sink fins 19 and on the other hand a projection 20 with a mounting flange 21 project integrally and in IG radial direction from the jacket 12.

A secondary winding 22 is wound on a coil form 23 and into it is inserted a primary winding 24; this is arranged on the sleeve 11, and the portions of the sleeve 11 and of the bottom 13 which are adjacent to the primary winding 24 have an insulating layer

I

00 t e.1 -3r *0- Two L-shaped core halves 27 are made of lamellar sheet iron (magnetizable material) are riveted together by means of their legs and form a closed 0-shaped core 26. The sleeve 11 receives one leg 28 of the core 26 positively, and the parallel leg 29 on the outside relative to the sleeve 11 is arranged in the projection 20 of the housing 10 and secured by means of a rivet 30. The secondary winding 22 and primary winding 20 and the portion of the leg 28 projecting beyond the latter are embedded in an insulating compound 31 which, functioning as a sealing compound, is a cast resin. The white area indicated on Fig. 1 surrounding secondary winding 22 can be addi, tional insulation blocks or be filled with insulating compound.

4 0 -Isi4- 0100 t 0040* 0000 t t

X

v. 4

.I

t i i

Claims

1. Ignition coil for ignition systems of internal-combustion engines, said ignition coil including a multiple-leg closed core of magnetizable material, one leg of which is surrounded by a primary winding and a coaxial secondary winding, and with an insulating compound which surrounds said one leg and the windings and with means for conducting heat away from the coie, the thermal conductivity of said means being greater than that of the core, where- in said means is a housing with a sleeve which encloses and contacts said one leg of the core, and in that the sleeve is connected to a jacket by way of a floor to form -4 an annular trough, and said annular trough is filled with said insulating compound, in particular casting resin.

2. The ignition coil according to Claim 1, wherein the primary wind- ing is disposed within the secondary winding, said housing consists of alumi- nium and a portion of the sleeve which is adjacent to the primary winding and to the floor has an insulating layer.

3. The ignition coil according to Claim 2, wherein the sleeve and the floor as well as the jacket are split by a continuous gap.

4. The ignition coil according to any one of the preceding Claims, wherein the core is ring-shaped and formed by two L-shaped core halves, and a radial projection with a fastening flange as an integral tunit stands out from the jacket of the housing, and in that an externally-located leg of the core, in particular a leg parallel to the sleeve, is located in the projection. The ignition coil according to any one of the preceding Claims, wherein a plurality of heat sink fins project out from the jacket. PSI j p.

I 14 004 U t -I P 4..

6. The ignition coil according to Claim 3 or 4, wherein the floor and the jacket have an outwardly protruding web with U-shaped cross section, said web being removed after pouring-in of the casting resin into the annular trough.

7. An ignition coil for ignition systems of internal-combustion engines substantially as hereinbefore described with reference to the accompanying drawing. DATED this 24th day of October, 1989. ROBERT BOSCH GMBH By its Patent Attorneys: CALLINAN LAWRIE I*Y V" t1l 4 -6-