Abstract: According to the invention, an electromagnetic switch includes a pair of fixed contacts, a movable magnetic core, a magnetic coil, and a fixed magnetic core. The movable magnetic core is configured to be moved by a magnetic attraction, thereby establishing an electrical connection between the fixed contacts. The fixed magnetic core is configured to create the magnetic attraction when the magnetic coil is energized. The fixed magnetic core has a base portion and a disc portion. The base portion is arranged to face the movable magnetic core. The disc portion is fixed to the base portion and formed of a stack of metal sheets including at least one base metal sheet and a balance metal sheet. The balance metal sheet has a thickness that is predetermined to balance a difference between a desired thickness of the disc portion and a total thickness of the at least one base metal sheet.

Abstract: In an electromagnet switch, a stationary iron core is composed mainly of a base part and a disk part. The base part is faced to a plunger and the disk part is forcedly inserted and fixed to a boss part formed in the base part. The disk part is composed of a metal plate of ferromagnetic substance (iron plate) and another substance plate (made of resin or rubber and the like, for example,) of a smaller spring constant or a larger damping coefficient than that of the metal plate. The metal plate and another substance plate are laminated. Another substance plate absorbs or reduces the impact force when the plunger is electromagnetically attracted toward and collides with the base part. The propagation of a large impact noise or crashing sound is thereby suppressed, and as a result the impact noise can be reduced.

Abstract: In a starter, an electromagnetic switch is mounted to a seating. A lead wire of an exciting coil is led to an outside of a switch case by a coil-leading portion and is connected to a male terminal, which is fixed to the coil-leading portion by welding. The coil-leading portion is integrally provided with an end plate portion of a bobbin around which the exciting coil is wound. The coil-leading portion passes through and projects from a bottom surface of the switch case to the outside. A metal member, in a form of a plate, is insert-molded in the seating. A 50 terminal is provided on an end of the metal member and a female terminal is provided on an opposite end of the metal member. When the electromagnetic switch is mounted to a predetermined position of the seating, the female terminal engages with the male terminal.

Abstract: An electromagnetic switch for use in actuating a starter for automotive vehicles is provided. The switch includes fixed contacts, a moving contact, and a plunger shaft. The moving contact is joined to a plunger shaft through an insulator. The plunger shaft is to be moved magnetically to bring the moving contact into abutment with the fixed contact to establish electric communication between the fixed contact. The switch also includes a rotation holder working to hold the moving contact and the insulator from rotating relative to each other. Use of the rotation holder results in a decrease in wear of the insulator. This eliminates the need for the insulator to have an additional thickness which would be worn down, thus permitting the insulator to be reduced in thickness to shorten the overall length of the switch.

Abstract: A starter solenoid switch according to the present invention includes a first and a second set of contacts that are disposed between a battery and a starter motor in parallel with each other. The first and the second sets of contacts are so configured that the second set of contacts is closed to supply a lighter electric current to the starter motor before the first set of contacts is closed to supply a heavier electric current to the same. The second set of contacts is composed of a second fixed contact and a second movable contact, one of which includes a low-resistance portion at one end thereof and a high-resistance portion that contains more carbon than the low-resistance portion. The low-resistance and the high-resistance portions are serially disposed along a conducting path of electric current from the battery to the starter motor, thereby ensuring reliability of the starter solenoid switch.

Abstract: A pinion gear of a starter is engaged with a ring gear of an internal combustion engine by restricting rotation of the pinion gear while driving a motor at a low speed. After the engagement is established, the motor is driven at a full speed by supplying a full current, thereby cranking up the engine. After the engine is cranked up, the engagement between the pinion gear and the ring gear is released. In order to prevent the motor from being driven at the full speed before the pinion gear fully engages with the ring gear, rigidity of a crank bar for restricting the pinion rotation is made sufficiently high to generate a spring-load that exceeds a force for driving a plunger that closes a switch for supplying the full current.

Abstract: A starter solenoid switch according to the present invention includes a first and a second set of contacts that are disposed between a battery and a starter motor in parallel with each other. The first and the second sets of contacts are so configured that the second set of contacts is closed to supply a lighter electric current to the starter motor before the first set of contacts is closed to supply a heavier electric current to the same. The second set of contacts is composed of a second fixed contact and a second movable contact, one of which includes a low-resistance portion at one end thereof and a high-resistance portion that contains more carbon than the low-resistance portion. The low-resistance and the high-resistance portions are serially disposed along a conducting path of electric current from the battery to the starter motor, thereby ensuring reliability of the starter solenoid switch.

Abstract: A carrier portion includes a side wall portion which restricts shifting of rollers in the axial direction. The side wall portion has a receiving hole formed at a radial central region. A clutch outer, integrally formed with the carrier portion, is rotatably supported via a bearing by a front axial end portion of an armature shaft. The bearing is fixed by press fitting on an inner cylindrical surface of the receiving hole. A tapered portion, provided at an edge of the front axial end portion of the armature shaft, is a guide surface for guiding the armature shaft into the bearing. The length of the front axial end portion is determined in such a manner that the side surface of a sun gear can contact with the side surfaces of the planetary gears in the axial direction after the tapered portion entirely enters inside the bearing.

Abstract: A starter for cranking an internal combustion engine includes an electric motor, an output shaft driven by the motor, a pinion gear spline-coupled to the output shaft, a restricting member, and a magnetic switch having a plunger. Movement of the plunger is transmitted to the restricting member via a crank bar connecting the plunger and the restricting member. After the pinion gear is engaged with a ring gear of the engine by restricting its rotation by the restricting member, the engine is cranked up by rotating the pinion gear at a full speed. The crank bar is separated into two parts, and after the two parts are assembled into the starter and correctly positioned therein, two parts are firmly connected to each other. In this manner, a process of assembling is simplified, and the crank bar couples the magnetic switch to the restricting member without forming operating gaps.

Abstract: An electromagnetic switch includes a contact holding member connected to a plunger in order to hold a first movable contact. The contact holding member is disposed outside a switch case covering a periphery of an excitation coil. A return spring pushes the plunger back in the opposite direction to a fixed iron core through the contact holding member when electric power supply to the excitation coil is stopped. The return spring is disposed outside the switch case. In this structure, a spring holding portion does not need to be disposed in the fixed iron core and the plunger. Therefore, an area where the fixed iron core attracts the plunger can be increased, so that an attraction force can be increased.

Abstract: An electromagnetic switch includes a contact holding member connected to a plunger in order to hold a first movable contact. The contact holding member is disposed outside a switch case covering a periphery of an excitation coil. A return spring pushes the plunger back in the opposite direction to a fixed iron core through the contact holding member when electric power supply to the excitation coil is stopped. The return spring is disposed outside the switch case. In this structure, a spring holding portion does not need to be disposed in the fixed iron core and the plunger. Therefore, an area where the fixed iron core attracts the plunger can be increased, so that an attraction force can be increased.

Abstract: In a starter, an electromagnetic switch is mounted to a seating. A lead wire of an exciting coil is led to an outside of a switch case by a coil-leading portion and is connected to a male terminal, which is fixed to the coil-leading portion by welding. The coil-leading portion is integrally provided with an end plate portion of a bobbin around which the exciting coil is wound. The coil-leading portion passes through and projects from a bottom surface of the switch case to the outside. A metal member, in a form of a plate, is insert-molded in the seating. A 50 terminal is provided on an end of the metal member and a female terminal is provided on an opposite end of the metal member. When the electromagnetic switch is mounted to a predetermined position of the seating, the female terminal engages with the male terminal.

Abstract: A magnet switch for a starter includes a exciting coil member, a switch case, a stator core, a plunger disposed in a hollow portion of the exciting coil to confront the stator core through an air gap, a link member connected to the plunger and disposed outside the switch case, a movable contact supported and insulated by the link member to move together with the plunger; and a stationary contact disposed opposite the movable contact. The link member has a pair of arms which axially extend along outer surfaces of the switch case. The switch case, the exciting coil and the plunger respectively have elliptic cross sections. The pair of arms is disposed to extend along the minor axis of the elliptic cross section to be movable in the axial direction of the switch case along the outer surface thereof.

Abstract: A pinion gear of a starter is engaged with a ring gear of an internal combustion engine by restricting rotation of the pinion gear while driving a motor at a low speed. After the engagement is established, the motor is driven at a full speed by supplying a full current, thereby cranking up the engine. After the engine is cranked up, the engagement between the pinion gear and the ring gear is released. In order to prevent the motor from being driven at the full speed before the pinion gear fully engages with the ring gear, rigidity of a crank bar for restricting the pinion rotation is made sufficiently high to generate a spring-load that exceeds a force for driving a plunger that closes a switch for supplying the full current.

Abstract: A pinion gear of a starter motor is driven into engagement with a ring gear of an internal combustion engine by a driving lever having a leaf spring upon energization of an electromagnetic actuator. The leaf spring of the driving lever is coupled to a connecting member of a plunger of the electromagnetic actuator. The connecting member includes a surface engaging with an engaging portion formed at one end of the leaf spring. A center portion of the engaging surface is projected toward the leaf spring, so that the engaging portion of the leaf spring always contacts the engaging surface at the center of the engaging surface, even if the leaf spring is slantedly coupled with the connecting member.

Abstract: In a magnetic switch for a starter motor, a magnetic core member providing a magnetic flux path is composed of separate components: a first core, a cylindrical yoke and a second core, all contained in a cup-shaped frame in close contact to one another. The first core is forcibly inserted into the cup-shaped frame, and the cylindrical yoke formed by rounding a flat plate into a C-shaped body having a small opening is also forcibly inserted in the cup-shaped frame by squeezing the small opening. The separate components are firmly pressed to each other by an axial force generated by caulking an open end of the cup-shaped frame. A switch cover is connected to the magnetic core member not to loosen the axial force connecting the components. Thus, magnetic resistance increase in the magnetic flux path formed by separate components is effectively suppressed.

Abstract: A pinion gear of a starter motor is driven into engagement with a ring gear of an internal combustion engine by a driving lever having a leaf spring upon energization of an electromagnetic actuator. The leaf spring of the driving lever is coupled to a connecting member of a plunger of the electromagnetic actuator. The connecting member includes a surface engaging with an engaging portion formed at one end of the leaf spring. A center portion of the engaging surface is projected toward the leaf spring, so that the engaging portion of the leaf spring always contacts the engaging surface at the center of the engaging surface, even if the leaf spring is slantedly coupled with the connecting member.

Abstract: In a magnetic switch for a starter motor, a magnetic core member providing a magnetic flux path is composed of separate components: a first core, a cylindrical yoke and a second core, all contained in a cup-shaped frame in close contact to one another. The first core is forcibly inserted into the cup-shaped frame, and the cylindrical yoke formed by rounding a flat plate into a C-shaped body having a small opening is also forcibly inserted in the cup-shaped frame by squeezing the small opening. The separate components are firmly pressed to each other by an axial force generated by caulking an open end of the cup-shaped frame. A switch cover is connected to the magnetic core member not to loosen the axial force connecting the components. Thus, magnetic resistance increase in the magnetic flux path formed by separate components is effectively suppressed.