FR2661216A1 - INTEGRATED INDIVIDUAL IGNITION COIL OF INTERNAL COMBUSTION ENGINE THERMAL MOTOR CANDLE AND CONTROL IGNITION. - Google Patents

Abstract

- Ignition of thermal engine. - The spool includes:. a housing (10) extended at its bottom (12) by a partly conductive barrel (13) provided with means (16) for adapting a cap (17),. a double tubular coil body (35) concentrically carrying a primary winding (38) and outside the latter a secondary winding (39),. a top cap (50) carrying a connector (60) and snapped onto the double coil body,. a laminated mass (70) adapted to the housing and comprising a central bar (71) passing through the double coil body,. and a coating (62) filling the housing and embedding the double coil body. - Application to motor vehicle engines.

Description

i

S.A R L ELECTRICFIL INDUSTRY

  INTEGRATED INDIVIDUAL IGNITION COIL OF MOTOR CANDLE

  THERMAL WITH INTERNAL COMBUSTION AND IGNITION CONTROL

  The present invention relates to the technical field of internal combustion thermal engines and more particularly to spark-ignition engines by

through candles.

  The invention is more particularly directed to ignition systems in which each spark plug is equipped with an electrical energy transformation coil able to supply it, from a low-voltage electrical energy source, with high voltage energy required for the production of an ignition spark inside the combustion chamber

that such a team candle.

  If initially the ignition systems of such engines included a single transformer coil whose high-voltage current was then distributed to each of the candles via a mechanical or electronic distributor, a technical evolution has shown for some time a proposal according to which each candle is equipped with an integrated single ignition coil The objective in such a case is to reduce the length of the conductors or cables ensuring the transmission of high voltage energy, in an attempt to eliminate electrical leakage important to the operation of the engine but also to the environment

radio-electric motors.

  At the same time, there is also a structural evolution of the engines, in order to improve their performance, reduce their consumption and reduce the pollution they cause. To this end, the engines are designed to work at more compression rates. high and at higher temperatures One of the structural consequences is the transformation of the cylinder head which usually involves deep wells

  at the bottom of which are implanted spark plugs.

  Such a structure poses problems of mechanical and electrical connection between the spark plug and the coil, especially when the latter, made in the form of an integrated block

  individual, must be adapted also on the breech.

  It should be considered further that the existence of variable types of engines leads to equally variable shapes and depths of the cylinder head, so that it is necessary to make the individual ignition coil packages into various shapes and sizes. many, complementary to the different

  structures likely to be encountered.

  Such an obligation does not make it possible to resort to mass production which makes it possible to lower significantly the

cost price.

  Such an obligation does not guarantee that an irreproachable mechanical and electrical connection

  in any case between the integrated ignition coil and the spark plug.

  The object of the invention is to fill the above gap by proposing a new integrated individual ignition coil specially designed to be mass-produced, at an attractive cost, while offering a possibility of adaptation the different construction characteristics of the motor cylinder heads, and in particular the well depths to ensure good cooperation and a good electrical and dielectric mechanical connection between the connection terminal of a

  spark plug and the built-in individual ignition coil.

  To achieve the above objectives, the integrated ignition coil of an internal combustion engine spark ignition spark plug is characterized in that it comprises: a housing or a tank open on top and extended by its bottom by a partially conductive barrel provided with means of adaptation of a mechanical, electrical and dielectric cooperation cap with the connection terminal of a spark plug, a double tubular coil body concentrically carrying a primary winding and externally to this last a secondary winding of which a terminal is connected to the barrel, said double coil body being fitted on snap tabs rising from the bottom of the housing, an upper cap carrying a connector connected to the two terminals of the primary winding and at the second terminal of the secondary winding, said cap being snapped onto the double coil body, a laminated mass adapted to the housing and comprising a central bar passing through the double coil body internally to the primary winding, and a plastic coating filling the housing and embedding the double coil body, the windings and the cap except

the connector.

  Various other features emerge from the

  description given below with reference to the accompanying drawings which

  show, by way of non-limiting examples, forms of

  accomplishment of the object of the invention.

  Fig 1 is an elevation partly in section of a coil

  integrated ignition system according to the invention.

  FIG. 2 is a cutaway elevation taken according to the

line II-II of FIG.

  Fig 3 is a perspective partly torn off

corresponding to figs 1 and 2.

  FIGS. 4 and 5 are partly cutaway perspectives illustrating two variant embodiments of one of the elements

  constituent parts of the integrated coil.

  FIGS. 1 and 2 show an integrated ignition coil of a spark plug 1 of a heat engine, located at the bottom of a well 2 of a cylinder head 3 of such a motor. The coil designated as a whole by the reference 4 is intended to be mounted on the yoke 3 to be interposed between the candle 1 and a power cable 5, for example from a selective distributor 6 of the electronic type, powered directly or indirectly from a source of storage such as

  battery 7 or a production source such as an alternator.

  The device 6 is designed to produce a temporary power failure of the coil 4 which is charged, from a low-voltage supply provided by the cable 5, to produce, as is conventional, a high-voltage current. the candle 1 which conventionally comprises a shank 8, as well as a connection terminal 9 constituted in the usual way by

example by an olive.

  The integrated individual ignition coil 4 comprises a housing or tank 10, preferably made of a suitable plastic material, for example polybutylene terephthalate obtained by injection molding. The housing 10 comprises an open top 11 and a bottom 12 from which extends downwardly a barrel 13 made of an insulating material, being able internally of a conductive core 14, such as a metal bar ending at the open end portion of the barrel 13 by a contact pad 15 The barrel 13 forms, externally and recessed from its open end, means 16 for adapting a tubular cap 17 for mechanical, electrical and dielectric cooperation with the spark plug 1 The cap 17 is made of a relatively flexible material, non-conductive, in particular silicone and represents a intermediate element responsible for electrical connection and mechanical adaptation, as well as dielectric leaktightness and protection Between the barrel 13 and the spark plug 1 For this purpose, the cap 17 forms a covering cap 18 able to be fitted with sealing on the barrel 8 The cap 17 internally comprises a conductor 19 elastically deformable establishing a certain electrical connection between the 15 and the terminal 9 The elastic conductor 19 is advantageously constituted by a helicoldal spring working on compression or a

conductive rubber cylinder.

  The means 16 may be constituted in several different ways Advantageously, these means involve a collar 20 formed projecting at the periphery of the barrel 13 to cooperate with a complementary groove 21 presented by a housing 22 formed in the cap 17 to allow interlocking In this case, the housing 22 is extended by a cylindrical bore 23 in which is disposed the conductor 19 which is normally constrained, after assembly of the cap 17 on the end portion of the barrel 13, between the stud 15 and a inner abutment shoulder 24 able to be traversed by the connection terminal 9 of the candle 1 after interlocking the endpiece

  18 on the drum 8 of the latter.

  In one possible embodiment, the barrel 13 forms an integral part of the bottom 12 of the casing 10. In a preferred embodiment, as illustrated by FIGS. 2 and 3 in particular, the barrel 13 is constituted by an independent piece made by injection in particular of a suitable plastic material such as polybutylene terephthalate The barrel 13 extends in such a case, from a collar 25, for example cylindrical, intended to be fitted into a base 26 formed by the bottom 12 The base 26 is preferably concentric with an opening 27 bordered by a flange 28 able to cooperate with a rabbet 29 formed in the connection zone between the barrel 13 and the collar 25. effective centering between the barrel 13 and the housing 10, as well as the establishment of a tight connection, in particular by interposition of a joint

  sealing ring 30 of the toric type for example.

  The casing 10 internally contains a bobbin. The bobbin body 35 consists of a primary coil body 36 made of any suitable insulative material and a secondary coil body 37 concentric to the first one surrounding it. The primary coil body carries a primary winding 38 , while the secondary body 37 carries a secondary winding 39 The section and length characteristics, as well as the insulation of the primary and secondary windings, should be considered as falling within the skill of the person skilled in the art. and 37 are made of plastic, so that they can be threaded concentrically and axially into an abutment position in which an axial immobilization snap occurs for example via a peripheral projection 40 formed by the coil body. secondary 37 and engaged behind at least one protrusion 41 presented by the primary coil body As can be seen from Fig. 1, and 3 the coil bodies are made in a substantially tubular form on which the primary and secondary windings

  are established in a conventional way.

  According to one embodiment of the invention, the double coil body is mounted inside the housing 10, so as to be snapped onto the bottom 12 of the latter. In a particularly advantageous constructive arrangement, the snap-in occurs between moldings 42. formed by the secondary coil body 37 and latching tabs 43 rising from the bottom 12. In the preferred embodiment of the invention, the tabs 43 rise from the collar 25, which also forms ribs. stop 44 on which come to bear some at least concentric fins 45 formed by the secondary coil body 37 In this way, an engagement snap in the direction of the arrow f 1 occurs automatically between the double coil body and the housing 10 Such a snap ensures a firm and resistant mechanical connection, as well as a centering which can be completed, in particular, by the existence of spans formed p ar the primary coil body 36, in order to

  cooperate with the corresponding inner faces of the housing 10.

  The coil according to the invention furthermore comprises a cap 50 intended to be engaged through the open top 11 to be fitted on the double bobbin body 35. Preferably, the cap 50 comprises a plate 51 provided with locking lugs. 52 and abutment ribs 53, so as to be snap fit on the secondary coil body, in a manner similar to that described above The tabs 52 and the ribs 53 cooperate in this direction with the

  moldings 42 and at least some of the fins 45.

  The cap 50 carries a connector 60 which rises from the plate 51 to project out of the open top 11 The connector 60 is, for example, of the type with three connection blades 61, two of which 61a and 61b are connected to the two terminals of the primary winding 38 and the third 61c of which is connected to one of the terminals of the secondary winding 39 whose other terminal

  is connected directly or indirectly to the conductive core 14.

  All of the constituent parts above are immobilized inside the casing 10, in particular by means of a coating 62 made of insulating plastic material, cast to fill and embed the double coil body, as well as

the tray 51.

  The coil is completed by the presence of a laminated mass 70 passing through the housing 10 to be inserted inside the primary coil body 36. In known manner, the laminated mass 70 comprises two closure loops surrounding the housing 10 and a bar central 71 passing through the primary coil body The mass is held on the housing by means of a staple belt 72 Preferably, the mass 70 is associated with a sole 73 forming tabs 74 of

  direct or indirect fixation on the cylinder head 3.

  FIG 4 shows an embodiment of the laminated mass 70 in the form of two sets 701 and 702 shaped to be placed face to face and together define the bar 71 central. An alternative embodiment is illustrated in FIG 5 in which the laminated mass comprises a carcass 703 overmolded in the tank 10 and associated with an independent bar 71, around which is threaded or overmoulded the primary body 36 of the coil. By the above means, it becomes possible to produce, by mass production and at an attractive cost price, an individual integrated ignition coil, all of whose constituent elements are associated by simple snapping prior to embedding in In fact, it is possible to form a snap-fit assembly comprising the primary winding, the secondary winding, the cap and the barrel on which, together, the electrical connections can be made positively and then mounted,

  then, this set in the boxer.

  It is also possible to mold the stacker and the laminated mass 703 by molding, and then to mount by

  snap, the previous set.

  The constitution of the case and the barrel 13 also makes it possible to envisage a specific manufacture as a function of the lengths to be conferred on the barrel to respect the different depths of wells likely to be encountered In this way, it is possible to make the production of the cap 17 in one length, which allows to lower the cost of manufacture by using large series of production from a raw material whose relatively large base price can be offset only by means of a

manufacture in very large series.

  The above advantage is more particularly acquired in the case of producing a barrel 13 as an independent piece of the housing 10 Indeed, it becomes possible to limit the variable adaptation factor as a function of the depth of the wells, from different ranges of manufacture of guns 13 of variable length that can always be mounted and adapted on or in the housing 10 in traditional production lines without affecting the rates of production.

manufacture of these.

  The adaptation of the length of the barrel 13 as a function of the depth of the well makes it possible to implement a cap 17 of constant length, calculated so that its natural bending is relatively limited, so as to obtain, during the adaptation of the individual integrated ignition coil on the cylinder head 3, a certainty of engagement of the tip 18 on the barrel 8 and cooperation between the conductor 19 and the olive 9 mechanical cooperation functions, electrical and dielectric devolving the cap 17 are thus assumed in all cases by providing a certainty of mechanical and electrical connection by simple

  introduction of the cap 17 inside the well 2.

  The invention is not limited to the examples described and represented, since various modifications can be made to it.

without leaving his frame.

Claims (7)

CLAIMS:   1 integrated ignition coil of an internal combustion engine spark ignition engine, characterized in that it comprises: a housing or tank (10) open on top (11) and extended by its bottom ( 12) by a partly conducting barrel (13) provided with means (16) for fitting a cap (17) for mechanical, electrical and dielectric cooperation with the connection terminal (9) of a candle (1), a double tubular coil body (35) concentrically carrying a primary winding (38) and externally thereto a secondary winding (39) having a terminal connected to the barrel, said double coil body being fitted on snap lugs ( 43) rising from the bottom of the housing, an upper cap (50) carrying a connector (60) connected to the two terminals of the primary winding and the second terminal of the secondary winding, said cap being snapped onto the double coil body, a laminated mass (70) fitted to the housing and comprising a central bar (71) passing through the double coil body internally to the primary coil, and a coating (62) of synthetic material filling the housing and embedding the double coil body, the windings and hat aside the connector.   2 integrated ignition coil according to claim 1, characterized in that the barrel (13) is an integral part of the bottom (12) of the housing.   3 integrated ignition coil according to claim 1, characterized in that the barrel (13) is constituted by an independent piece nested sealingly by a collar (25) which it forms, in a centering base (26) presented by the bottom (12)   around an opening (27) for the passage of the barrel.   4 integrated ignition coil according to claim 3, OS characterized in that the collar (25) has, opposite the barrel, abutment ribs (44) and latching lugs (43) able to cooperate respectively with fins (45) and   moldings (42) of the double coil body.   Integrated ignition coil according to one of   Claims 1 to 3, characterized in that the barrel (13) comprises   internally a conductive core (14) and at the end forms an external insertion flange (20) in a complementary groove (21) presented by the inner surface of the cap (17) which internally contains a conductor (19) deformable elastically in permanent contact with the conductive soul. 6 integrated ignition coil according to claim 1, characterized in that the double coil body (35) is constituted by two independent bodies (36) and (37) nested concentrically.   7 integrated ignition coil according to claim 1, characterized in that the cap (50) is constituted by a plate (51) whose one face is surmounted by the connector (60) and whose other face forms in protruding abutment ribs (53) and detent lugs (52) able to cooperate respectively with the fins and moldings of the double body of coil.   8 integrated ignition coil according to claim 1, characterized in that the laminated mass (70) is maintained on the   housing by a staple belt (72).   9 integrated ignition coil according to claim 1, characterized in that the laminated mass (70) is integrated by molding on the housing (10).   Integrated ignition coil according to claim 1, 8 or 9, characterized in that the laminated mass (70) is associated with a sole (73) having fastening tabs (74). on the cylinder head of an engine.