Electromagnetic clutch control system for automobiles

• US 4,723,644 A
• Filed: 09/09/1985
• Issued: 02/09/1988
• Est. Priority Date: 09/13/1984
• Status: Expired due to Fees

• Current Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Sakakiyama, Ryuzo
• Primary Examiner(s): Bonck, Rodney H.
• Assistant Examiner(s): Lorence, Richard M.
• Application Number:
  US06/774,253
• Time in Patent Office: 883 Days
• Field of Search: 192/0.033, 192/0.052, 192/0.076, 192/0.092, 192/0.096, 192/21.5
• US Class Current: 477/175
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: F16D 2037/001 Electric arrangements for clutch control
• CPC Class Codes: F16D 2037/002 characterised by a single substantially axial gap in which the fluid or medium consisting of small particles is arranged
• CPC Class Codes: F16D 2500/10412 Transmission line of a vehicle
• CPC Class Codes: F16D 2500/3022 Current
• CPC Class Codes: F16D 2500/3108 Vehicle speed
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/31466 Gear lever
• CPC Class Codes: F16D 2500/7041 Position
• CPC Class Codes: F16D 2500/70418 Current
• CPC Class Codes: F16D 37/02 the particles being magnetisable
• CPC Class Codes: F16D 48/064 Control of electrically or electromagnetically actuated clutches F16D48/062, F16D48/068 take precedence
• CPC Class Codes: F16D 48/068 using signals from a manually actuated gearshift linkage

Abstract

A system for controlling an electromagnetic clutch of an engine for a motor vehicle having a transmission. The system has various sensors such as an engine speed sensor, a vehicle speed sensor for detecting low vehicle speed, an accelerator pedal position sensor for detecting the acceleration of the engine, and a selector lever position sensor. The system has a computing unit for determining the clutch current at the beginning of engagement of the electromagnetic clutch. The rate of change of clutch current with respect to engine speed increases as the acceleration of engine speed increases.

Claims

1. A system for controlling an electromagnetic clutch of an engine for a motor vehicle having a transmission, comprising:

engine speed sensing means for producing an engine speed signal dependent on the engine speed of the engine;

vehicle speed sensing means for producing a vehicle speed signal in a low vehicle speed range;

acceleration determining means responsive to the engine speed signal for producing an accleration signal representing magnitude of acceleration of the engine speed;

selector lever position detecting means for producing a selector lever signal when a selector lever of the transmission is positioned at a position other than a neutral position and a parking position;

circuit means for supplying clutch current to a magnetizing coil of the electromagnetic clutch for engaging the clutch;

control means responsive to the engine speed signal, vehicle speed signal, acceleration signal, and selector lever signal for controlling said circuit means to determine the clutch current at engagement of the electromagnetic clutch, the control means being such that the rate of change of clutch current with respect to engine speed increases as the magnitude of acceleration of the engine speed increases.

2. The system according to claim 1, wherein

the control means comprises a microcomputer.

3. The system according to claim 2 wherein

said control means is for reading out a magnitude of the clutch current from a table in accordance with the magnitude of the acceleration of the engine speed.

4. The system according to claim 3, wherein

said control means is for controlling the clutch current I(N) according to the value N_i, where N is the engine speed and N_i is a correcting value equal to N(1+C_n), where C_n =C_n-1 +Kα

, where C_n is a coefficient, K is a constant, n is number of engine acceleration measurement repeated at predetermined intervals, and α

is acceleration of the engine speed.