Driving force control system for four-wheel drive vehicles

• US 6,419,040 B2
• Filed: 12/13/2000
• Issued: 07/16/2002
• Est. Priority Date: 12/24/1999
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Uchiyama, Naoki, Nakasako, Toru, Taguchi, Satoshi, Kitano, Kazuhiko, Hirakawa, Mitsuaki, Yamamoto, Akihiro
• Primary Examiner(s): LERNER, AVRAHAM H
• Application Number:
  US09/734,542
• Publication Number:
  US 20010005704A1
• Time in Patent Office: 580 Days
• Field of Search: 180/242, 180/243, 180/197, 180/65.2, 180/65.4, 701/69, 477/107
• US Class Current: 180/243
• CPC Class Codes: B60K 17/354 having separate mechanical assemblies for transmitting drive to the front or to the rear wheels or set of wheels
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60K 28/165 acting on elements of the vehicle drive train other than the propulsion unit and brakes, e.g. transmission, clutch, differential acting on brakes B60T8/17
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• 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 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: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/0677 Engine power
• CPC Class Codes: B60W 2710/086 Power
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: F16H 2059/467 of torque converter
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/916 : with plurality of drive axles

Abstract

A four-wheel drive vehicle is provided in which the main driven wheels are driven by an engine via a torque converter and the auxiliary driven wheels are driven by an electric motor. The response of the vehicle to the operation of the accelerator is improved by suppressing in advance the slip of the main driven wheels due to an excess output of the engine. The main driven wheels are driven by an engine via a torque converter and auxiliary driven wheels are driven by an electric motor. The vehicle is started by the output of the electric motor in the region in which the speed ratio of the torque converter is small (that is to say, the region in which the efficiency is low) such as when the vehicle is starting, and when it enters the region in which the speed ratio of the torque converter exceeds 0.8 and the efficiency exceeds 85% the drive of the electric motor is stopped or suspended and the vehicle is made to travel by means of the output of the engine.

Claims

1. A driving force control system for a four-wheel drive vehicle comprising main driven wheels driven by an engine via a torque converter, speed ratio detecting means for detecting the speed ratio of said torque converter and auxiliary driven wheels driven by an electric motor independently from the engine, the control system comprising

a control means coupled to said speed ratio detecting means for controlling the distribution ratio of the output generated by the engine and the output generated by the electric motor according to the speed ratio of said torque converter.

2. A driving force control system for a four-wheel drive vehicle according to claim 1, wherein the speed ratio of said torque converter at which the drive of the electric motor is stopped is different from the speed ratio of said torque converter at which the drive of the electric motor is started.

3. A driving force control system for a four-wheel drive vehicle according to claim 1, wherein main driven wheel speed detecting means and auxiliary driven speed detecting means are coupled to said control means and wherein said control means determines the state of slip of said main driven wheels and said control means changes the maximum output of said electric motor according to the state of slip of said main driven wheels.

4. A driving force control system for a four-wheel drive vehicle according to claim 1, wherein said electric vehicle is driven in a region in which the speed ratio of the torque converter is low when the vehicle is starting and, in accordance with an increase in said speed ratio of the torque converter, the drive of the electric motor is stopped.

5. A driving force control system for a four-wheel drive vehicle according to claim 4, wherein the drive of the engine is stopped and said electric vehicle is driven in said region in which the speed ratio of the torque converter is low when the vehicle is starting and, in accordance with an increase in said speed ratio of the torque converter, the drive of the electric motor is stopped and the engine is driven.