Vehicular electric power generation apparatus and method

• US 6,291,903 B1
• Filed: 06/25/1999
• Issued: 09/18/2001
• Est. Priority Date: 08/04/1998
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Horibe, Mitsutoshi
• Primary Examiner(s): ENAD, ELVIN GENARGUE
• Application Number:
  US09/344,486
• Time in Patent Office: 816 Days
• Field of Search: 290/40-A-, 290/40-S-, 180/16.J, 180/65.S, 180/65.D, 372/28
• US Class Current: 290/40.00A
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator

Abstract

In a vehicular electric power generation apparatus having an a.c. generator and an engine, a rotation speed of the a.c. generator at the idling rotation operation of the engine is set to be higher than a rotation speed, at which the driving torque of the a.c. generator becomes a maximum. Thus, the rotation speed of the a.c. generator does not change through the rotation speed at which the driving torque of the vehicle a.c. generator becomes a maximum, even when the rotation speed of the engine is raised high for running of a vehicle. Thus, changes in the load applied to the engine can be restricted.

Claims

1. A vehicular electric power generation apparatus comprising an a.c. generator, the a.c. generator producing a maximum torque at which an output power of the a.c. generator is highest at a maximum torque rotation speed and being configured to be driven normally in a range of rotation speeds, said range of speeds being higher than said maximum torque rotation speed;

and

an internal combustion engine configured to drive the a.c. generator;

wherein an idling rotation speed of the a.c. generator is set higher than the maximum torque rotation speed, the idling rotation speed occurring during an idling rotation operation of the internal combustion engine; and

wherein a lowest rotation speed within the range of rotation speeds is set more than 100 revolutions per minute higher than the maximum torque rotation speed during a cold operating state.

2. A vehicular electric power generation method comprising:

driving an a.c. generator using an engine and a rotation transmitting device, the a.c. generator being driven to produce a maximum torque at one rotation speed at which an output power of the a.c. generator is highest; and

maintaining a rotation operation speed of the engine after starting the engine so that the a.c. generator is driven at another rotation speed higher than the one rotation speed;

wherein the other rotation speed corresponds to an idling rotation speed of the engine, the idling rotation speed being a lowest speed among normal rotation speeds of the engine; and

wherein the other rotation speed is more than 100 revolutions per minute higher than the one rotation speed.

3. A vehicular electric power generation apparatus comprising:

an a.c. generator configured to produce a maximum torque at which an output power of the a.c. generator is highest at a maximum torque rotation speed, said a.c. generator being configured to be driven normally in a range of rotation speeds, said range of rotation speeds being faster than said maximum torque rotation speed, a driving torque of said a.c. generator during said maximum torque rotation speed being less than a driving torque of said a.c. generator rotated in said range of rotation speeds; and

an internal combustion engine configured to drive the a.c. generator;

wherein an idling rotation speed of the a.c. generator is set higher than the maximum torque rotation speed, the idling rotation speed occurring during an idling rotation operation of the internal combustion engine;

wherein a lowest rotation speed within the range of rotation speeds is set more than 100 revolutions per minute higher than the maximum torque rotation speed during a cold operating state; and

wherein said a.c. generator is rotated within said range of rotation speeds by said engine when said engine rotates at speeds greater than or equal to said idling rotation speed, said a.c. generator being rotated at said maximum torque rotation speed by said engine when said engine rotates at a speed less than said idling rotation speed.