Method and apparatus for detecting friction heat of a clutch and regulating the clutch

A method of regulating the operation of a torque transmission system having heat generating friction surfaces and being installed in a motor vehicle with a regulating device which is operable by a control unit, comprising the steps of transmitting to the control unit signals denoting at least the magnitude of torque being transmitted by the system, the extent of slip of said friction surfaces relative to each other, and a selected speed of a variable-speed assembly receiving torque from the system;

• utilizing at least one of said signals to ascertain the input of energy by the control unit into the friction surfaces of the system;
• calculating the temperature of at least a portion of the system as a function of time;
• comparing the calculated temperature with a threshold value;
• and utilizing the control unit to regulate the operation of the system under at least one of the circumstances including (a) detection of a calculated temperature which exceeds the threshold value and (b) starting of the vehicle at a speed of the variable-speed assembly above a predetermined maximum starting speed, said utilizing step including generating at least one signal for indication of thermal stressing which exceeds a predetermined threshold value.

A method of regulating the operation of a torque transmission system having heat generating friction surfaces and being installed in a motor vehicle with a regulating device which is operable by a control unit, comprising the steps of transmitting to the control unit signals denoting at least the magnitude of torque being transmitted by the system, the extent of slip of friction surfaces relative to each other, and a selected speed of a variable-speed assembly receiving torque from the system;

• utilizing at least one of said signals to ascertain the input of energy by the control unit into the friction surfaces of the system;
• calculating the temperature of at least a portion of the system as a function of time;
• comparing the calculated temperature with a threshold value;
• and utilizing the control unit to regulate the operation of the system under at least one of the circumstances including (a) detection of a calculated temperature which exceeds the threshold value and (b) starting of the vehicle at a speed of the variable-speed assembly above a predetermined maximum starting speed, said utilizing step including generating at least one signal for indication of thermal stressing which exceeds a predetermined threshold value and for initiation of a corrective undertaking.

Apparatus for regulating the operation of a torque transmission system having heat generating friction surfaces slidable relative to each other and being installed in a power train of a motor vehicle between a prime mover and a variable-speed assembly having first, second and additional forward speeds and a reverse speed, comprising an adjustable device operable to select the torque which is transmittable by said system;

• and means for adjusting said device including a control unit having input means connected with at least one of a plurality of components for supplying signals denoting at least one of several variable parameters indicating the RPM of the prime mover, the speed of the assembly, the magnitude of transmitted torque and the extent of slip of the friction surfaces relative to each other, said control unit including means for ascertaining on the basis of at least one of said signals (a) a friction energy input at said friction surfaces as a function of time and (b) at least one temperature of said system, for comparing said at least one temperature with at least one threshold value, and for carrying out at least one of a plurality of undertakings including generating output signals denoting excessive thermal stressing of said system due to starting of the vehicle at said additional forward speeds of the assembly and initiating protective measures when the at least one temperature exceeds the at least one threshold value.

Apparatus for regulating the transmission of torque by a torque transmission system having heat generating friction surfaces which can slip relative to each other and being installed in a power train of a motor vehicle between an engine and a multispeed transmission, comprising a central control unit having input means connected with at least one of a plurality of components for supplying signals denoting at least one of several variable parameters indicating the speed of the transmission, the magnitude of transmitted torque and the extent of slip of said friction surfaces relative to each other, said control unit having means for determining on the basis of data and other system parameters at least one of (a) the friction energy input at least within a given range of operation of said system, (b) the temperature of at least a portion of said system and (c) critical conditions of the vehicle including ascertaining on the basis of at least one of said signals an energy input at least within a given range of operation of said system or a temperature at least within a given range of operation of said system or a condition indicative of wear upon said system, said control unit further having means for selecting the torque which is transmittable by said system as a function of time when at least one of (i) the ascertained temperature, (ii) the ascertained energy input and (iii) the duration of energy input exceeds a predetermined threshold value and for indicating at least one of stressing, wear upon an temperature which exceeds a predetermined threshold value of said system.