Power unit for motor vehicles

• US 5,552,988 A
• Filed: 12/06/1994
• Issued: 09/03/1996
• Est. Priority Date: 09/03/1991
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Cho, Toshiyuki, Kawaguchi, Kenji, Fujii, Takaaki, Honda, Satoshi, Toriyama, Masayuki, Motodate, Shoji
• Primary Examiner(s): Chin, Gary
• Application Number:
  US08/354,730
• Time in Patent Office: 637 Days
• Field of Search: 364/426.01, 364/426.02, 364/424.07, 303/93, 303/95, 303/100, 303/103, 180/220, 180/221, 180/65.3, 180/65.4, 180/65.6, 180/65.8
• US Class Current: 701/70
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: B62K 2202/00 Motorised scooters
• CPC Class Codes: B62K 2204/00 Adaptations for driving cycles by electric motor
• CPC Class Codes: B62K 23/02 hand actuated arrangements of controls on handle-bars of engine-driven cycles B62K11/14
• CPC Class Codes: B62K 23/04 Twist grips
• CPC Class Codes: B62K 25/283 for cycles without a pedal crank, e.g. motorcycles
• CPC Class Codes: B62M 7/12 with the engine beside or within the driven wheel
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• CPC Class Codes: H02P 6/08 Arrangements for controlling the speed or torque of a single motor H02P6/10, H02P6/28 take precedence
• CPC Class Codes: H02P 6/16 Circuit arrangements for detecting position
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A regenerative braking system in a motor vehicle determines a state of deceleration on the basis of the number of revolutions of a motor and an accelerator signal and performs a regenerative braking according to the state of deceleration. The regenerative braking system includes a revolution sensor for detecting the number of revolutions of a rotor of a vehicle driving motor and an accelerator opening sensor in a RAM stores discrimination data for discriminating between a regenerative braking mode and a drive mode on the basis of the number of revolutions of the rotor and the accelerator opening and also stores on-off duty ratio data of FETs in the regenerative braking mode and that in the drive mode. A CPU retrieves on-off duty ratio data corresponding to the number of revolutions of the rotor and the accelerator opening in the regenerative braking mode when the regenerative braking mode is determined on the basis of the rotor revolutions and the accelerator opening, and controls the FETs at an on-off duty ratio corresponding to the retrieved on-off duty ratio data. The power unit for the motor vehicle is an electric motor mounted in unit cases using at least a portion of the unit cases as a motor case. In the power unit of such construction, a heat sink is attached to the motor case. Switching elements are provided for controlling an electric current to be supplied to the electric motor. The switching elements are mounted to the heat sink.

Claims

1. A regenerative braking system for a motor vehicle comprising:

a revolution sensor for detecting the number of revolutions of a drive motor driving said motor vehicle;

an accelerator opening sensor for detecting an accelerator opening;

a discriminator means for discriminating between a regenerative braking mode and a drive mode based on the number of revolutions of the drive motor and the accelerator opening and for producing a signal responsive thereto;

a plurality of switching elements for switching an electric current flowing in said drive motor;

a memory means for storing on-off duty ratio data of said switching elements in the regenerative braking mode in a corresponding relation to the number of revolutions of the drive motor and the accelerator opening; and

control means for retrieving said on-off duty ratio data corresponding to the number of revolutions of the drive motor and the accelerator opening from said memory means when the signal generated by the discriminator means indicates that the system is in the regenerative braking mode, and for controlling the switching elements at an on-off duty ratio corresponding to the retrieved on-off duty ratio data to effect regenerative braking.

2. The regenerative braking system for a motor vehicle according to claim 1, wherein approximately a drive motor driving force zero line is set as a boundary between the regenerative braking mode and the drive mode in said discriminator means.

3. The regenerative braking system for a motor vehicle according to claim 1, wherein regenerative braking is employable during high speed operation of the motor vehicle with a zero level of an accelerator signal provided by said accelerator opening sensor.