Mitsuba Corporation

Mitsuba Electric Mfg. Co., Ltd.

Mitsuba Electric Manufacturing Co., Ltd.

Eiichi Kimura

Shinichi Nagashima

Koji Nara

Michio Okada

Yoshikazu Sato

Masaaki Ohya

Mitsuhiro Kogure

Hitoshi Ono

Kazuhiro Yamamoto

Shigeki Miyazaki

In an engine starter, to facilitate the assembling of a solenoid assembly, an annular outer peripheral wall is formed in the casing for receiving the energization solenoid assembly and to secure the solenoid assembly by crimping a free end of the annular outer peripheral wall onto an axial end of the solenoid assembly, and the energization solenoid assembly is fitted into the bore defined by the annular outer peripheral wall by engaging the outer periphery of the solenoid assembly with three fingers of an assembly tool. A plurality of crimping portions are defined by a plurality of recesses provided along the circumferential direction of the free end of the annular outer peripheral wall so that the fingers of an assembling tool when inserting the solenoid assembly are not interfered by the annular outer peripheral wall.

Assembling arrangement for engine starters

In an engine starter including a solenoid device for actuating a switch for the electric motor and to drive the pinion into mesh with the ring gear of an internal combustion engine, the solenoid device includes an armature outer member which moves in the direction to push out the pinion against the spring force of a first return spring in the energized state of the solenoid device, and an armature inner member which is resiliently urged by a second return spring, and is telescopically disposed with respect to the armature outer member with a coil spring interposed coaxially between them. An annular spring retainer is press fitted into the inner bore of the armature outer member to receive a corresponding coil end of the coil spring. The spring retainer is stamp formed from non-magnetic material so as to have cylindrical portion which is fitted into the bore of the armature inner member, a flange portion which is bent perpendicularly from the cylindrical portion in the manner of an inwardly directed flange in its installed state, and a guide piece portion which is bent perpendicularly with respect to the axial direction from the free end of the flange portion. The forming of the armature outer member is thereby simplified, and the guide piece portion supports the coil spring with a centering action. More importantly, the spring retainer which may be made of non-magnetic material can prevent any significant leakage of magnetic flux from the spring retainer.

Coaxial engine starter

Starting electric motor for automobile

In an electric motor comprising a plurality of permanent magnets (46) surrounding a motor armature (52) for supplying field flux to the armature, a cylindrical magnet cover (47) is fitted into an inner circumferential surface defined by the permanent magnets to protect the permanent magnets against chipping and other damages. The magnet cover is further provided with a radial flange (47b) having guide holes (47c) formed therein so that set bolts (48) passed axially inside the motor casings may be favorably guided as they are inserted from one axial end of the motor casing to the other. Preferably, to better guide the bolts, the guide holes may be each provided with a cylindrical guide boss (50, 51) which may be formed either by burring or cutting and lifting a part of the material of the flange.

Electric motor using permanent field magnets

In a coaxial engine starter comprising a pinion (6) connected to the output shaft (4) which is driven by an electric motor (3), via a helical spline (19), a switch unit (7) for selectively closing a power supply line to the electric motor, and a solenoid device (9) consisting of an annular armature and an annular energization coil surrounding the output shaft to axially drive the pinion and a moveable contact of the switch unit in the axial direction, the switch is adapted to be closed before the pinion is actuated by the solenoid device. Therefore, the output requirement for the solenoid device can be reduced as opposed to the conventional starter in which the pinion is actuated strictly by the solenoid device, and the size of the engine starter can be reduced.

Coaxial engine starter system

In an engine starter comprising a pinion slidably fitted on the output shaft for driving a ring gear of an engine that is to be started, and a one-way clutch having a first end secured to the pinion and a second end which is engaged by the output shaft via spline means, a compression coil spring is interposed between a stopper secured to the output shaft and an annular shoulder defined in a cylindrical extension of the second end of the one-way clutch. Therefore, even when the pinion is forced into a high speed rotation by the engine which has been started by the engine starter, the pinion simply rotates freely, and no friction is applied to the compression coil spring or the stopper. Also, by receiving the compression coil spring in an annular space defined between the cylindrical extension of the second end of the one-way clutch and the output shaft, the compression coil spring can be protected from the centrifugal force which acts upon the compression coil spring when the output shaft of the engine starter rotates at an extremely high speed.

Engine starter system having an improved pinion assembly

In a coaxial engine starter comprising a pinion connected to the output shaft which is driven by an electric motor, via a helical spline, a switch unit for selectively closing a power supply line to the electric motor, and a solenoid device consisting of an annular armature and an annular energization coil surrounding the output shaft to axially drive the pinion and a moveable contact of the switch unit in the axial direction, the energization coil is disposed between the electric motor and the pinion with a commutator of the electric motor facing the energization coil, and a pigtail for one of the brushes is directly connected to the moveable contact. Also, the contacts of the switch unit are placed between a pair of adjacent brushes of the commutator. In particular, by separating the part of the armature for driving the moveable contact from the part of the armature for driving the pinion, the stroke of the moveable contact can be minimized, and the stress acing upon the connecting part of the pigtail upon movement of the contact can be minimized.

An electromagnetic switch suitable for controlling large electric current in starter motors or the likes comprising a rod which is actuated in a longitudinal direction by an electromagnet, a fixed contact member, and a moveable contact member carried by the rod for selective engagement with the fixed contact member by energization and deenergization of the electromagnet. The moveable contact member is allowed to rotate around an axial line perpendicular to the axial line of the rod so that the moveable contact can achieve a favorable contact even when the fixed contact member involves dimensional errors, and that the moveable contact may be easily detached from the fixed contact member even when the two contact members are partly fused together. The rotational movement of the moveable contact member can be achieved by yieldably or elastically holding the moveable contact member between a pair of convex surfaces on the rod. Alternatively, a combination of a planar holding surface and a coned disc spring interposed between the planar holding surface and the moveable contact member may be used in place of one of the convex surfaces.

Electromagnetic switch

In a starter system for an internal combustion engine, an input member of an overrunning clutch is provided with an annular shoulder surface abutting an annular end surface of a cylindrical boss portion of a reduction gear unit casing when the overrunning clutch is at a rest position, and a cylindrical sleeve portion extends from the annular shoulder surface towards the reduction gear unit so as to be closely fitted on the cylindrical boss portion of the reduction gear unit casing. Thus, water and other foreign matters are not only shut off by these mutually abutting annular surfaces, but also prevented from reaching this region by the cylindrical sleeve portion closely fitted on the cylindrical boss portion of the reduction gear unit. Also, the centrifugal force prevents water and other foreign matters from reaching this area when the starter is actuated and the two annular surfaces are not in contact.

Starter system for an internal combustion engine

A starter system for an internal combustion engine having a casing provided with a mounting circumferential surface adapted to be substantially closely fitted into an associated mounting bore provided in the engine or a transmission housing associated therewith, and a mounting flange extending radially from the casing and provided with a mounting end surface perpendicular to a longitudinal line of the output shaft of the starter system and spaced from the mounting circumferential surface along the longitudinal line. Because of the presence of the distance between the mounting end surface of the mounting flange and the mounting circumferential surface of the starter casing closely fitted into the mounting bore, the reaction force acting on the pinion is prevented from being amplified and transmitted to the mounting surfaces by means of an undesirable lever action.

Growing community of inventors

Kiryu, Japan

Eiichi Kimura