Method and device for regulating the temperature of an internal combustion engine

Abstract

A method and device for regulating engine temperature. The device includes a valve control system arranged on a pipe of a cooling circuit of an internal combustion engine connecting the engine to a radiator. The pipe includes a temperature sensor arranged at the engine output and upstream of the valve control system that is automatically opened under effect of a cooling liquid being heated to a set temperature in accordance with a predetermined setpoint profile, ranging between a minimum stored temperature setpoint and a maximum stored temperature setpoint, so that the temperature of the engine gradually reaches the minimum or maximum setpoint by maintaining the control valve system more or less wide open. A controller controls the initial opening of the control valve system enabling the opening of the control valve system to be controlled when the control valve system has already been initially opened.

1 - 10 . (canceled) 
   
   
       11 : A device for regulating engine temperature, comprising:
 a valve control system placed on a line of a cooling circuit of an internal combustion engine connecting the engine to a radiator, the line including a temperature sensor placed at an outlet of the engine and upstream of the valve control system, which is automatically opened under effect of a coolant being heated to a temperature setpoint;   means for varying the temperature setpoint in accordance with a predefined setpoint profile, ranging between a minimum stored temperature setpoint and a maximum stored temperature setpoint, so that the temperature of the engine gradually reaches the minimum or maximum setpoint to attenuate thermal shock by maintaining the control valve system more or less wide open; and   means for controlling the first opening of the control valve system and for checking that the first opening of the control valve system has already taken place.   
   
   
       12 : The device for regulating engine temperature as claimed in  claim 11 , wherein the means for effecting a more or less wide opening of the valve control system in accordance with the predefined setpoint profile includes a heating resistor used to prematurely increase or decrease the temperature of a wax plug of the valve control system, respectively causing the opening or the closing of a check valve, and are controlled by computation device placed in a computer. 
   
   
       13 : The device for regulating engine temperature as claimed in  claim 12 , wherein the computation device placed in a computer includes at least one first computation module that determines the lowest minimum and maximum temperature limits in accordance mutually with the minimum and maximum temperature setpoints stored in a storage in the computer, a second computation module that calculates plural intermediate temperatures of the setpoint profile between the minimum temperature limit and the maximum temperature limit, a comparison module that compares the temperature measured continuously at the engine outlet by the temperature sensor during the driving, with the intermediate temperatures calculated with the second computation module to determine the difference between the two temperatures, and a correction module that corrects the difference and serves to define the necessary opening of the thermostat to reach the desired temperature setpoint according to the measured difference. 
   
   
       14 : The device for regulating engine temperature as claimed in  claim 13 , wherein the computation device further includes a thermostat control module associated with the correction module. 
   
   
       15 : A method for regulating engine temperature implementing the device as claimed in  claim 11 , comprising:
 varying the temperature setpoint so that the engine temperature gradually reaches a maximum temperature when the first opening of the valve control system has already taken place.   
   
   
       16 : The method for regulating engine temperature as claimed in  claim 15 , further comprising:
 determining a minimum temperature setpoint and a maximum temperature setpoint and storing these two temperature setpoints in a storage of a computer;   determining by a first computation module a minimum temperature limit from the minimum temperature setpoint and a maximum temperature limit from the maximum temperature setpoint and storing these two temperature setpoints in the storage of the computer;   determining by a second computation module intermediate temperatures as a function of the minimum and maximum temperature limits;   measuring continuously, during the driving time, the temperature of the coolant contained in the circuit at the outlet of the engine and downstream of the valve control system with a sensor;   comparing the temperature at the engine of the various intermediate temperatures to determine a difference; and   correcting the difference in temperature by opening or closing the valve control system.   
   
   
       17 : The method for regulating engine temperature as claimed in  claim 16 , wherein the minimum temperature setpoint is between 80° C. and 85° C. and the maximum temperature setpoint is between 100° C. and 120° C. 
   
   
       18 : The method for regulating engine temperature as claimed in  claim 17 , wherein the minimum temperature setpoint is 90° C. and the maximum temperature setpoint is 110° C. 
   
   
       19 : The method for regulating engine temperature as claimed in  claim 18 , wherein the minimum temperature limit is 92° C. when the minimum temperature setpoint is 90° C., and the maximum temperature limit is 108° C. when the maximum temperature setpoint is 110° C. 
   
   
       20 : The method for regulating engine temperature as claimed in  claim 16 , wherein the opening and closing of the valve control system are carried out by turning on a heating mechanism located in the valve control system that prematurely reaches the temperature setpoint allowing the opening or closing of the valve control system.