GB1604129A

GB1604129A - Magnetically controlled ignition distributor

Info

Publication number: GB1604129A
Application number: GB23452/78A
Authority: GB
Original assignee: Ducellier et Cie
Current assignee: Ducellier et Cie
Priority date: 1977-06-09
Filing date: 1978-05-26
Publication date: 1981-12-02
Also published as: ES470421A1; IT1096382B; DE2825398A1; DE2825398C2; IT7824317A0

Description

(54) MAGNETICALLY CONTROLLED IGNITION DISTRIBUTOR (71) We, DUCELLIER & CIE, a French Body Corporate located at Echat 950, 94024 Creteil Cedex, France, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to a magnetically controlled ignition distributor for a motor vehicle internal combustion engine adapted to influence an electronic circuit at the instant of ignition and having a housing, a rotor and a stator assembly, the rotor being driven in rotation by the distributor shaft which rotates in a bearing of the housing.

An object of the present invention is to provide a magnetically controlled ignition distributor of relatively economical construction and improved efficiency as compared with some conventional distributors of this type.

According to the present invention, a magnetically controlled ignition distributor for an internal combustion engine adapted to influence an electronic circuit at the instant of ignition, comprises a housing, a rotor driven in rotation by a distributor shaft rotatable in a bearing of the housing and in a second bearing provided by an axial part of a cap attached to the housing, the rotor having axially extending peripheral pole teeth and being adapted for connection to a centrifugal advance corrector so as to be angularly adjustable thereby, a stator assembly disposed in the vicinity of said second bearing, a part of the stator assembly being adapted for connection to a depression-actuated advance corrector so as to be movable thereby and including a support plate carrying a pole piece having peripheral teeth extending axially in the opposite diree- tion to the rotor teeth so as to surround the rotor and coil and past which the pole teeth of the rotor move in succession, and an axially magnetised permanent magnet of annular form on said pole piece and concentric with the distributor shaft, the stator assembly also including a coil fixedly retained within the cap and surrounded by the teeth of the pole piece, the coil having a winding of annular form disposed concentrically with the distributor shaft in the vicinity of the pole piece, the rotor being spaced from its connection with the centrifugal advance corrector in a direction towards the coil and being connected to the centrifugal advance corrector by means of a sleeve which surrounds the shaft and around which the movable stator part is adapted to turn under the action of the depression actuated advance corrector, the arrangement being such that part of the coil is in direct facing relationship with the distributor shaft so that the magnetic flux from the coil is conducted between the stator and the rotor through the distributor shaft.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 illustrates one form of the ignition distributor of the invention, and Figure 2 illustrates an alternative form of the ignition distributor of the invention.

Referring to the drawings, the ignition distributor shown therein includes, in known manner, a shaft 1 rotating in a bush 3 held in a bearing 2a of the housing 2 of the distributor, a centrifugal advance corrector 4 being provided (not shown in detail in the drawing , fast with a sleeve 5 which surrounds a portion of the distributor shaft 1. A rotor 6 is held, at the upper part of the sleeve 5, fast for rotation with the latter.

This rotor 6 is in the form of a rotary plate concentric with the shaft 1 and has at its periphery pole teeth which extend upwardly in the axial direction of the distributor and of which the number is a function of the number of cylinders of an engine to which the distributor is intended to be fitted. The pole teeth 6a move in rotation between a winding 7 and the teeth 8a of a stator 8 forming part of a stator assembly.

The stator assembly disposed adJacent the upper part of the rotor 6 is held within a cap 11 which fits onto the upper part of the housing 2 and is fixed to the latter by screws 16 or by other convenient means. The cap 11 serves as a cover for the housing 2 and includes at its upper part a bearing 11a having a bush 12 in which the shaft 1 rotates.

Around this bush 12 a sleeve 13 retains the stator assembly free for rotation with respect to the bush 12. The stator assembly can thus, if necessary, be angularly displaced by means of a system 15 actuated by the vacuum pressure, referred to for convenience as depression, prevailing in the engine.

The stator assembly includes a winding 7 of annular form co-axial with the shaft 1 and disposed within the rotor 6, a stator 8 in the form of a circular plate co-axial with the shaft 1 which includes at its periphery pole teeth 8a which extend in the axial direction of the distributor and which are outside the rotor 6, an annular permanent magnet 9 co-axial with the distributor shaft and in contact with the upper face of the stator 8, and finally a support plate 10 in contact with the upper face of the magnet 9 and connected to the depression-actuated advance corrector system 15.

In the embodiment of Figure 1 the support plate 10, the magnet 9 and the stator 8, fixed together, are retained by the sleeve 13 and include openings to permit the passage of rods 7a by means of which the winding 7 is held fixed directly on the bearing 11a by means of screws 14. These openings are sufficiently long to permit the angular displacement of the plate 10, the magnet 9 and stator 8 under the action of the corrector system 15.

In the embodiment of Figure 2, the winding 7 is held by a support 17 moulded in insulating material in the form of a dish of which the periphery includes cut-outs 17a of width sufficient to permit the free passage, and the possible displacement as a function of the depression, of the pole teeth 8a of the stator 8. This dish includes a rim 17b which centres itself in the cap 11, itself being centred on the housing 2 of the distributor.

This dish 17 is gripped between the cap 11 and the housing 2 when the cap is assembled on the latter by the screws 16. Positioning abutments for the dish are formed (not shown) in the cap 11. The bottom of the dish 17 includes openings 17c in order to permit the passage of rivets 7b solid with the winding 7. This arrangement has the advantage of not providing superfluous holes in the plate 10, magnet 9 and stator 8 of the stator assembly and of facilitating the assembly and dismantling if necessary of the ignition distributor.

By virtue of the arrangement of the invention the winding 7 directly faces the distributor shaft 1 without the interposition of the sleeve 13 or bush 12, and it can thus be brought as near as possible to the shaft 1 and thus can conserve the maximum amount of the active part of the flux.

Since there are less parts arranged in axial succession than in some conventional magnetic generators, it reduces to a minimum the number of parts for alignment and thus permits larger tolerances and consequently the use of less costly manufacturing processes. Moreover, the fact of placing the rotor in the vincinity of the centrifugal advance corrector permits a considerable reduction in the length of the sleeve 5 which carries the rotor 6 and a part of the centrifugal advance corrector.

The fact of disposing the stator assembly within the cap 11 facilitates the assembly of the stator externally of the housing and faciliatates its dismantling, should it become necessary, as well as access to the rotor and to the centrifugal advance device, because no special tools are necessary for dismantling the distributor.

Since the shaft 1 rotates in two bearings, the distributor of the,ns the invention has a better resistance to vibrations in than distributors in which the shaft rotates in only one bearing, this arrangement minimising inaccuracy of the magnetic generator. The distributor can thus be mounted horizontally as well as vertically. Moreover, the bearing 11a ensures sealing between the magnetic generator and the distributor head and there are thus less parasitic inductions acting on the magnetic generator.

Between the housing 2 and the head 11 there can be interposed, according to necessity, other modules, such as for example a depression sensor module, whilst conserving the advantages of a two bearing distributor.

Finally, assembly of the depressionactuated advance corrector 15 can be effected more easily than in known devices in which this device 15 is inconveniently positioned because of the conventional location of the stator adjacent to the centrifugal advance device.

It is clear that modification can be made to the described embodiments without departing from the scope of the invention and particularly the number and positions of pole teeth at the periphery of the rotor and stator will be a function of the number of cylinders of the symmetrical or asymmetrical engine with which the distributor is intended for use. Moreover, the support piece 17 of Figure 2 could be flat rather than m the form of a dish and could include both the cut-outs 17a and orifices 17c.

WHAT WE CLAIM IS: 1. An ignition distributor for an internal combustion engine adapted to influence an electronic circuit at the instant of ignition, and comprising a housing, a rotor driven in rotation by a distributor shaft rotatable in a bearing of the housing and in a second bearing provided by an axial part of a cap attached to the housing, the rotor having axially extending peripheral pole teeth and being adapted for connection to a centrifugal advance corrector so as to be angularly adjustable thereby, a stator assembly disposed in the vicinity of said second bearing, a part of the stator assembly being adapted for connection to a depression-actuated advance corrector so as to be movable thereby and including a support plate carrying a pole piece having peripheral teeth extending axially in the opposite direction to the rotor teeth so as to surround the rotor and coil and past which the pole teeth of the rotor move in succession, and an axially magnetised permanent magnet of annular form on said pole piece and concentric with the distributor shaft, the stator assembly also including a coil fixedly retained within the cap and surrounded by the teeth of the pole piece, the coil having a winding of annular form disposed concentrically with the distributor shaft in the vicinity of the pole piece, the rotor being spaced from its connection with the centrifugal advance corrector in a direction towards the coil and being connected to the centrifugal advance corrector by means of a sleeve which surrounds the shaft and around which the movable stator part is adapted to turn under the action of the depression actuated advance corrector, the arrangement being such that part of the coil is in direct facing relationship with the distributor shaft so that the magnetic flux from the coil is conducted between the stator and the rotor through the distributor shaft.

2. An ignition distributor according to Claim 1, wherein the winding is fixedly retained within the cap by means of fixing elements passing through the part of the stator which is movable under the action of the depression actuated advance corrector.

3. An ignition distributor according to Claim 1 wherein the winding is fixedly retained by a support of moulded insulating material having a peripheral rim which co-operates with the cap in order to centre and position the coil, the support having slots concentric with the shaft in which the polar teeth of the stator are adapted to move angularly under the action of the depression actuated advance corrector, said support being gripped firmly between the assembled cap and housing.

4. An ignition distributor substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the cut-outs 17a and orifices 17c. WHAT WE CLAIM IS:

1. An ignition distributor for an internal combustion engine adapted to influence an electronic circuit at the instant of ignition, and comprising a housing, a rotor driven in rotation by a distributor shaft rotatable in a bearing of the housing and in a second bearing provided by an axial part of a cap attached to the housing, the rotor having axially extending peripheral pole teeth and being adapted for connection to a centrifugal advance corrector so as to be angularly adjustable thereby, a stator assembly disposed in the vicinity of said second bearing, a part of the stator assembly being adapted for connection to a depression-actuated advance corrector so as to be movable thereby and including a support plate carrying a pole piece having peripheral teeth extending axially in the opposite direction to the rotor teeth so as to surround the rotor and coil and past which the pole teeth of the rotor move in succession, and an axially magnetised permanent magnet of annular form on said pole piece and concentric with the distributor shaft, the stator assembly also including a coil fixedly retained within the cap and surrounded by the teeth of the pole piece, the coil having a winding of annular form disposed concentrically with the distributor shaft in the vicinity of the pole piece, the rotor being spaced from its connection with the centrifugal advance corrector in a direction towards the coil and being connected to the centrifugal advance corrector by means of a sleeve which surrounds the shaft and around which the movable stator part is adapted to turn under the action of the depression actuated advance corrector, the arrangement being such that part of the coil is in direct facing relationship with the distributor shaft so that the magnetic flux from the coil is conducted between the stator and the rotor through the distributor shaft.