Starter for engine equipped with motor generator

• US 6,018,199 A
• Filed: 09/21/1998
• Issued: 01/25/2000
• Est. Priority Date: 03/20/1998
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hisamoto, Motoi, Shiroyama, Shigeru
• Primary Examiner(s): Ponomarenko, N.
• Application Number:
  US09/157,313
• Time in Patent Office: 491 Days
• Field of Search: 290/30 R, 290/31, 290/32, 290/34, 290/36 R, 290/37 A, 290/46, 123/179.1, 123/179.2, 123/179.3, 123/179.4
• US Class Current: 290/37.00A
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: F02N 11/006 using a plurality of electric motors
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 2011/0896 Inverters for electric machines, e.g. starter-generators
• CPC Class Codes: F02N 2200/023 Engine temperature
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor

Abstract

A starter for an engine equipped with a motor generator achieves lower cost and reduced sizes and capacities of circuit elements by reducing the assist load on the motor generator: it is provided with a motor generator (2) and a starting motor (10) connected to an engine (1); a startup state determining circuit (20) which determines the startup state from operating condition and selectively issues ON signals M1 and M2 to the motor generator and the starting motor; a key switch (6) which generates a start signal (Qe) at the time of starting the engine; and a temperature sensor 12 which generates a temperature signal (Te) corresponding to the temperature of the engine. The startup state determining circuit actuates only the motor generator as a motor in a startup state wherein the temperature signal indicates not less than a predetermined temperature corresponding to the warm-up state of the engine, while it actuates both the starting motor and the motor generator in a startup state wherein the temperature signal indicates a temperature below the predetermined temperature. And the startup state determining circuit actuates the starting motor first, then actuates the motor generator after a delay time corresponding to a rush current period of the starting motor has elapsed in the second startup state.

Claims

1. A starter for an engine equipped with a motor generator, comprising:

a motor generator directly connected to an engine;

a battery connected to said motor generator via an inverter;

a motor generator control circuit for controlling said motor generator via said inverter;

a starting motor composed of a DC motor connected to said engine at the time of startup;

an ON/OFF switch for selectively switching the feed of power from said battery to said starting motor;

various sensors for detecting the operating condition of said engine; and

a startup state determining circuit which determines the startup state of said engine according to the operating condition of said engine and selectively issues ON signals to said ON/OFF switch and said motor generator control circuit;

wherein said various sensors include a key switch for generating a startup signal at the time of starting up said engine and a temperature sensor for generating a temperature signal corresponding to the temperature of said engine;

said startup state determining circuit issues the ON signal only to said motor generator control circuit to actuate said motor generator as a motor in a first startup state wherein said temperature signal indicates not less than a predetermined temperature which corresponds to the warm-up state of said engine, while it issues the ON signal to both said ON/OFF switch and said motor generator control circuit to actuate both said starting motor and said motor generator in a second startup state wherein said temperature signal indicates a temperature below said predetermined temperature; and

said startup state determining circuit actuates said starting motor first, then actuates said motor generator after a delay time corresponding to a rush current period of said starting motor has elapsed in said second startup state.

2. A starter for an engine equipped with a motor generator according to claim 1, wherein:

said delay time is set within a range of 0.01 sec. to 0.5 sec.

3. A starter for an engine equipped with a motor generator, comprising:

a motor generator directly connected to an engine;

a battery connected to said motor generator via an inverter;

a motor generator control circuit for controlling said motor generator via said inverter;

a starting motor connected to said engine at the time of startup;

an ON/OFF switch for selectively switching the feed of power from said battery to said starting motor;

various sensors for detecting the operating condition of said engine which include a revolution sensor generating a revolution signal corresponding to the number of revolutions of said engine; and

a startup state determining circuit which determines the startup state of said engine according to the operating condition of said engine and selectively issues ON signals to said ON/OFF switch and said motor generator control circuit;

wherein said various sensors include a key switch for generating a startup signal at the time of starting up said engine and a temperature sensor for generating a temperature signal corresponding to the temperature of said engine;

said startup state determining circuit issues the ON signal only to said motor generator control circuit to actuate said motor generator as a motor in a first startup state wherein said temperature signal indicates not less than a predetermined temperature which corresponds to the warm-up state of said engine, while it issues the ON signal to both said ON/OFF switch and said motor generator control circuit to actuate both said starting motor and said motor generator in a second startup state wherein said temperature signal indicates a temperature below said predetermined temperature; and

the startup state determining circuit stops the ON signal to said ON/OFF switch if said revolution signal indicates not less than a first predetermined number of revolutions corresponding to the cranking speed of said engine after said starting motor and said motor generator are actuated in said second startup state.

4. A starter for an engine equipped with a motor generator according to claim 3, wherein:

said startup state determining circuit stops the ON signal to said motor generator control circuit if said revolution signal indicates not less than a second predetermined number of revolutions corresponding to the idling speed of said engine after the ON signal to said ON/OFF switch is stopped.

5. A starter for an engine equipped with a motor generator according to claim 3, wherein:

said various sensors include a revolution sensor generating a revolution signal corresponding to the number of revolutions of said engine; and

said startup state determining circuit stops the ON signals to said ON/OFF switch and said motor generator control circuit if said revolution signal indicates not less than a predetermined number of revolutions corresponding to the idling speed of said engine after said starting motor and said motor generator are actuated in said second startup state.