EP0502768B1 - Mounting method of a plurality of ignition coils on an engine block - Google Patents

Abstract

Method of mounting a plurality of ignition coils (12) on an engine block. <??>According to the invention it comprises the following stages:   - casting in an electrically insulating material a casing (1) forming a plurality of receivers (4) for the said coils and including, in the form of inserts, means (2) of fixing the said casing to the said engine block;   - fitting the said coils in the said receivers;   - wiring the connections (23, 24) to the primary and secondary windings of the said coils;   - pouring an electrically insulating resin (25) into the casing, thereby embedding the said coils and their wiring; and   - fixing the casing onto the said engine block. <IMAGE>

Description

The present invention relates to a mounting method a plurality of ignition coils on an engine block.

It is already known, in order to reduce the length high-voltage cables between an ignition coil unique and the different spark plugs of a internal combustion, to have an individual coil in the immediate vicinity of each of the candles.

However, this arrangement has the disadvantage of multiply the number of components and therefore the complexity of assembly operations.

It is also known to use only one coil for two candles, this coil having each end of its secondary winding connected to one of the two spark plugs, ignition occurring only on the spark plug desired for reasons of electrical conductivity gases in the respective cylinders.

If this arrangement effectively reduces the number of coils, it does not simplify them mounting operations since it requires wiring more complex high voltage.

• un boítier (1) formant une pluralité de logements (4) et réalisé dans une matière électriquement isolante et
• une pluralité de bobines (12) disposées dans lesdits logements et comprenant chacune un enroulement primaire et un enroulement secondaire.

Also known, from document WO-A-8500930, an electrical power supply assembly for the spark plugs of an engine block which can be installed in a single operation on the engine block. This set includes:

• a housing (1) forming a plurality of housings (4) and made of an electrically insulating material and
• a plurality of coils (12) disposed in said housings and each comprising a primary winding and a secondary winding.

However, in this set, each coil is all first housed in an individual box, then different individual boxes are assembled in one overall housing and connected by connections mounted in the housing cover. The realization of such a set therefore requires multiple operations.

The present invention aims to overcome this drawback.

To this end, the present invention has first of all for A method according to claim 1.

• monter dans ledit boítier, préalablement à la mise en place de la résine, un connecteur d'alimentation des enroulements primaires desdites bobines et des broches de connection aux bougies dudit bloc moteur; et
• câbler les liaisons basse-tension entre ledit connecteur et les enroulements primaires des bobines, d'une part, et les liaisons haute-tension entre les enroulements secondaires des bobines et lesdites broches de connection, d'autre part.

More particularly, the method according to the invention can comprise the steps consisting in:

• mounting in said housing, prior to the installation of the resin, a power connector for the primary windings of said coils and pins for connection to the spark plugs of said engine block; and
• wire the low-voltage connections between said connector and the primary windings of the coils, on the one hand, and the high-voltage connections between the secondary windings of the coils and said connection pins, on the other hand.

Thanks to the process according to the invention, it is therefore possible to achieve more simply than in prior art a one-piece assembly comprising the coils and their wiring, which are here kept in the housing by the insulating resin, this housing being then mounted in a single operation on the engine block.

The method according to the invention therefore presents the advantages of multiple coil arrangements while retaining a very simple assembly.

• la fig. 1 est une vue de dessus du boítier selon l'invention;
• la fig. 2 est une vue en coupe selon la ligne II-II de la fig. 1;
• la fig. 3 est une vue en coupe selon la ligne III-III de la fig. 1;
• la fig. 4 est une vue de dessus de l'ensemble selon l'invention avant mise en place de la résine; et
• la fig. 5 est une vue en coupe selon la ligne V-V après mise en place de la résine.

A particular embodiment of the invention will now be described, by way of nonlimiting example, with reference to the appended schematic drawings in which:

• fig. 1 is a top view of the housing according to the invention;
• fig. 2 is a sectional view along line II-II of FIG. 1;
• fig. 3 is a sectional view along line III-III of FIG. 1;
• fig. 4 is a top view of the assembly according to the invention before placing the resin; and
• fig. 5 is a sectional view along the line VV after placement of the resin.

As shown in fig. 1, the housing 1, present, seen from above, an elongated rectangular shape. This case is, in this case, provided for housing two coils with two outputs and is therefore intended for a motor with four cylinders.

This case is molded in one piece in a material insulating plastic and includes, embedded in this material plastic, inserts 2 for fixing to the engine block as well as the magnetic circuits 3 of the coils.

Box 1 forms inside the two circuits magnetic 3 of the housings 4 for the coils.

The housings 4 are connected by a channel 5 delimited by ribs 6 to a housing 7 opening to the outside from the housing, to receive the connection connections supply of the primary windings of the coils.

The housings 4 being after assembly of the housing on the engine block located directly above two of the spark plugs of this engine, are connected by channels 8 delimited by ribs 9 to housings 10 which, after mounting the housing on the engine block, are immediately above the other two candles.

After molding of the case 1 which has just been described, pins 11 are arranged at the bottom of the housings 4 and 10 to ensure the electrical connection of the spark plugs motor at the ends of the secondary windings of the coils.

These coils 12 are then themselves put in place in the housings 4 of the housing 1.

These coils are composed, in a known manner, of a core 13 on which are placed the winding bobbin 14 primary and the secondary winding coil 15. The primary winding 16 is wound on the bobbin 14 and the secondary winding 17 is wound on the bobbin 15.

The coils 12 are placed in the housings 4 of so that the cores 13 face each other magnetic return circuits 3.

A connector 18 is then placed in the housing 7, this connector 18 comprising, formed in one piece, a electrical connector 19 and an air duct 20. After installation, the conduit 20 is connected to passages air 21 intended to bring air to the engine block by through openings 22.

The electrical connector 19 is connected by links low voltage 23 to the primary windings 16 of coils 12 while the ends of the windings secondary 17 of the coils are connected to pins 11.

One end of each secondary winding is directly connected to pin 11 of its housing 4, the other end being connected to a pin of a housings 10 by a high-voltage cable 24.

The low-voltage supply wires 23 are arranged in channel 5 and the high-voltage cables 24 are arranged in the channels 8.

Once the wiring is finished, a resin electrically insulating is poured into the housings 4, 7 and 10 as well as in channels 5 and 8 immobilizing thus the coils 12 and their wiring as well as the double connector 18.

A cover 26 is then mounted on the housing 1 by any suitable means.

The assembly thus produced is assembled in a single operation on an engine block using the lugs fixing 27 of the inserts 2. It then suffices to connect connector 18 to its two power supplies and in respective air.

Of course, the invention also applies to a engine with a different number of cylinders from four as well as single output coils secondary.

Claims (2)

1. Method of mounting on an engine block a plurality of ignition coils (12) each comprising a primary winding and a secondary winding, this method comprising the steps consisting in, in succession:

   moulding in an electrically insulating material a casing (1) which includes, in the form of inserts, means (2) for fixing the said casing to the said engine block and the magnetic circuits (3) of the said coils, and which forms, inside the said circuits, a plurality of housings for the said coils;

   placing the said coils into the said housings;

   wiring the connections (23,24) to the primary and secondary windings of the said coils;

   pouring into the casing an electrically insulating resin (25) which in a single operation shrouds the said coils and their wirings; and

   fixing the casing to the said engine block.
2. Method according to Claim 1, comprising the steps consisting in:

   mounting in the said casing, prior to the placing of the resin, a connector (19) for powering the primary windings (16) of the said coils and the pins (11) for connection to the spark plugs of the said engine block; and

   wiring the low-voltage links (23) between the said connector and the primary windings of the coils on the one hand, and the high-voltage links (24) between the secondary windings (17) of the coils and the said connection pins on the other hand.

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