Starter for cranking internal combustion engine having main and auxiliary switches

• US 20040017086A1
• Filed: 06/12/2003
• Published: 01/29/2004
• Est. Priority Date: 07/25/2002
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Shiga, Tsutomu, Niimi, Masami
• Granted Patent: US 6,759,756 B2
• Time in Patent Office: Days
• US Class Current: 290/38R
• CPC Class Codes: F02N 11/0851 characterised by means for controlling the engagement or disengagement between engine and starter, e.g. meshing of pinion and engine gear
• CPC Class Codes: F02N 15/067 the starter comprising an electro-magnetically actuated lever
• CPC Class Codes: F02N 2300/102 Control of the starter motor speed; Control of the engine speed during cranking
• CPC Class Codes: H01H 50/543 Auxiliary switch inserting resistor during closure of contactor
• CPC Class Codes: H01H 51/065 Relays having a pair of normally open contacts rigidly fixed to a magnetic core movable along the axis of a solenoid, e.g. relays for starting automobiles details H01H50/20

Abstract

A starter includes an electric motor, a pinion gear driven by the electric motor and a magnetic switch having a plunger driven by a magnetic coil. Electric power to be fed to both the electric motor and the magnetic coil is supplied from an on-board battery through a single common input terminal of the starter. The magnetic switch is composed of a main switch through which a full power is supplied to the electric motor and an auxiliary switch through which a limited power is supplied. Upon closing the auxiliary switch, the motor is driven at a low speed and the pinion gear is engaged with a ring gear of the engine. Then, the main switch is closed to thereby crank up the engine with a full power.

Claims

1. A starter for cranking an internal combustion engine having a ring gear, the starter comprising:

an input terminal connected to an on-board battery;

an electric motor powered by the on-board battery;

a pinion gear driven by the electric motor, the pinion gear being adapted to be engaged with the ring gear; and

a magnetic switch for engaging the pinion gear with the ring gear and for electrically connecting and disconnecting the input terminal to the electric motor, the magnetic switch including a magnetic coil for driving the magnetic switch, wherein;

the magnetic coil is directly connected to the input terminal.

2. The starter as in claim 1, wherein:

the input terminal of the starter is connected to the on-board battery through a relay separated from the starter.

3. The starter as in claim 2, wherein:

the magnetic switch includes a main switch and an auxiliary switch connected in parallel to the main switch, both of the main and auxiliary switches being disposed between the input terminal and the electric motor; and

the auxiliary switch includes an electric resistor for limiting an amount of current supplied to the electric motor.

4. The starter as in claim 3, wherein:

upon energizing the magnetic coil, the auxiliary switch is first closed and then the main switch is closed.

5. The starter as in claim 4, wherein:

the electric resistor of the auxiliary switch is formed in its stationary contact substantially made of carbon.

6. The starter as in claim 4, wherein:

the electric motor includes a rotating armature having a commutator slidably contacting brushes for supplying electric current to the armature; and

a contact between the commutator and the brushes is utilized as the main switch.

7. The starter as in claim 1 further comprising a speed-reduction mechanism disposed between the electric motor and the pinion gear for driving the pinion gear at a reduced speed, wherein:

the pinion gear is engaged with the ring gear by pushing the pinion gear toward the ring gear while stopping rotation of the pinion gear upon energization of the magnetic switch; and

the pinion gear is positioned at one axial side of the electric motor while the magnetic switch is positioned at the other axial side of the electric motor.