US 4,071,792 AGranted

Engine ignition timing signal generator having a reduced number of permanent magnets

AssigneeRobert Bosch GmbH

InventorsHarald Kalippke, Richard Gerber, Karl Ehrmann

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Abstract

Four pole pieces embedded in the cylindrical periphery of a non-magnetic rotor disk are connected with each of a number of magnets embedded in the disk in circumferentially distributed positions spaced from the rotor shaft and from the disk periphery. Of these pole pieces, one circumferentially interleaved pair is connected with one pole of the magnet by a magnetically conducting yoke strip embedded in one circular face of the disk and the other pair is similarly connected with the other pole of the magnet. The spacing between the first and second pole piece is equal to the spacing between the third and fourth and less than that between the second and third, the latter spacing being equal to the spacing between groups of pole pieces associated with different magnets, for the case of a uniformly timed firing sequence of a multicylinder engine.

Claims5

Dependent claims

A timing signal generator for an electrical ignition system of an internal combustion engine having a rotor in the form of a pole wheel in which permanently magnetized magnet elements are set, which rotor is mounted on a shaft for rotation within a stator having an electrically transmitting element (21) responsive to the rotation of the rotor past the transmitting element for producing a signal in a control circuit of said ignition system, in which there is the improvement that said rotor comprises:

a disk-like matrix body (15) of non-magnetic material centered on said shaft (13) for carrying permanent magnets (16) and pole pieces (17,18,19,20) embedded therein, said matrix body (15) filling the angular intervals between said permanent magnets, having a cylindrical surface defining its periphery and being mounted on said shaft in a way that enables rotation of said shaft to produce coaxial rotation of said disk in the same direction of rotation;
a plurality of permanent magnets (16) embedded in said matrix body (15) at locations intermediate between said shaft and said periphery, and
a group of pole pieces (17,18,19,20) for each of said magnets (16) embedded in the periphery of said matrix body (15) and each connected to a pole of the magnet by an elongated magnetically conducting body embedded in said matrix body.

Dependencies are inferred from the claim text.