Automatic clutch control for coasting with brake-condition responsive hysteresis width

• US 6,024,673 A
• Filed: 02/19/1999
• Issued: 02/15/2000
• Est. Priority Date: 02/23/1998
• Status: Expired due to Fees

• Current Assignee: Transtron Inc. (Fujitsu Limited), Isuzu Motors Limited
• Original Assignee: Transtron Inc. (Fujitsu Limited), Isuzu Motors Limited
• Inventors: Kobayashi, Kuzuhiko, Arai, Hiroyuki, Hayashi, Masahiko
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Parekh, Ankur
• Application Number:
  US09/253,520
• Time in Patent Office: 361 Days
• Field of Search: 477/170, 477/171, 477/166, 477/175, 477/180, 477/71, 477/74, 192/3.58, 192/13 R, 192/3.63
• US Class Current: 477/171
• CPC Class Codes: B60W 2510/186 Status of parking brakes
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/14 Clutch pedal position
• CPC Class Codes: F16D 2500/3026 Stroke
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/30806 Engaged transmission ratio
• CPC Class Codes: F16D 2500/31413 Clutch pedal position
• CPC Class Codes: F16D 2500/31426 Brake pedal position
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/31466 Gear lever
• CPC Class Codes: F16D 2500/31473 Parking brake lever
• CPC Class Codes: F16D 2500/5085 Coasting
• CPC Class Codes: F16D 2500/702 Look-up tables
• CPC Class Codes: F16D 2500/70426 Clutch slip
• CPC Class Codes: F16D 2500/70663 State analysis; Analysing potential states of the machine and developing control strategies at each state
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect

Abstract

In a vehicle with an automatically controlled clutch in which ON-OFF of the friction clutch is automatically controlled by a controller, clutch control during coasting (with the accelerator depression amount being 0%) is conducted according to a clutch ON-OFF map for coasting provided in the controller.

Two different clutch ON-OFF maps for coasting are provided; one having a smaller hysteresis width, and the other having a larger hysteresis width. Clutch control during coasting is conducted by applying the map with a smaller hysteresis width when the brake pedal is stepped on or applying the map with a larger hysteresis width when the brake pedal is not stepped on. Thus, clutch ON-OFF hunting can be avoided, and smooth stopping can be conducted.

Claims

1. Automatic clutch control system for a vehicle comprising;

a gear position sensor, a vehicle speed sensor, a brake switch, an accelerator pedal depression amount sensor, a vehicle-controlling controller, and a friction clutch automatically ON-OFF controlled through the controller, in which the controller has two kinds of clutch ON-OFF maps with different hysteresis widths to be applied for controlling the clutch while coasting, one map with a smaller hysteresis width being applied while on a brake pedal is stepped on during coasting and the other map with a larger hysteresis width being applied while said brake pedal is not stepped on during coasting.