Method for the temperature regulation of an engine

Abstract

The invention concerns a method for regulating the temperature of an engine, in particular an internal combustion engine 12, in the case of which the engine is interconnected with a radiator 16 via at least one forward-delivery line 35 and at least one return-delivery line 44 within a cooling circuit 14, which said radiator can be bypassed via a valve-controlled bypass line 48 between the at least one forward-delivery line 35 and the at least one return-delivery line 44. Additionally, the cooling circuit 14 comprises at least one pump capable of being controlled via open-loop and/or closed-loop control, in particular an electric pump 34 for pumping a coolant through the connecting lines 32 of the cooling circuit 14, as well as an electronic control unit 52 that controls the cooling capacity of the cooling circuit 14 via open-loop and/or closed-loop control. It is proposed, according to the invention, that at least one component temperature of the engine 12 be determined based on the coolant temperature and the volumetric flow of the coolant through the engine 12.

What is claimed is:  
     
         1 . A method for regulating the temperature of an engine, in particular an internal combustion engine ( 12 ), in the case of which the engine is interconnected with a radiator ( 16 ) via at least one forward-delivery line ( 35 ) and at least one return-delivery line ( 44 ) within a cooling circuit ( 14 ), which said radiator can be bypassed via a valve-controlled bypass line ( 48 ) between the at least one forward-delivery line ( 35 ) and the at least one return-delivery line ( 44 ), and comprising at least one pump capable of being controlled via open-loop and/or closed-loop control, in particular an electric pump ( 34 ) for pumping a coolant through the cooling circuit ( 14 ), whereby an electronic control unit ( 52 ) controls the cooling capacity of the cooling circuit ( 14 ) via open-loop and/or closed-loop control, 
 wherein at least one component temperature of the engine ( 12 ) is determined based on a coolant temperature and a volumetric flow of the coolant through the engine ( 12 ).    
     
     
         2 . The method according to  claim 1 , 
 wherein the volumetric flow of the coolant pumped through the engine ( 12 ) is determined based on the electrical current (I) required by the pump ( 34 ).    
     
     
         3 . The method according to  claim 1 , 
 wherein the volumetric flow of coolant pumped through the engine ( 12 ) is determined based on the electrical voltage (U) applied to the pump ( 34 ).    
     
     
         4 . The method according to one of the preceding claims, 
 wherein a numeric model of the cooling circuit ( 14 ) with its components—in particular the engine ( 12 ), the pump ( 34 ), and its load curve and the connecting lines ( 32 )—is stored in data form in the electronic control unit ( 52 ), which said model describes the dependence of at least one component temperature of the engine ( 12 ) on the volumetric flow of coolant.    
     
     
         5 . The method according to  claim 4 , 
 wherein, to change the volumetric flow of coolant, at least one correction signal ( 55 ) is generated by comparing at least one determined actual component temperature with the data on the associated setpoint component temperature stored in the electronic control unit ( 52 ).    
     
     
         6 . The method according to one of the preceding claims, 
 wherein the coolant temperature is detected via at least one temperature sensor ( 72 ).    
     
     
         7 . The method according to  claim 6 , 
 wherein the change in temperature of the coolant over time is compared with a time-dependent model for the coolant temperature stored in the electronic control unit ( 52 ), and at least one second correction signal ( 56 ) is generated in accordance with a present deviation of the actual coolant temperature from the setpoint coolant temperature.    
     
     
         8 . The method according to  claim 1 , 
 wherein the delivery quantity of the pump ( 34 ) is controlled via open-loop and/or closed-loop control in accordance with the at least one first ( 55 ) and/or the at least one second ( 56 ) correction signal in order to change the volumetric flow of coolant.    
     
     
         9 . The method according to one of the preceding claims, 
 wherein at least one valve located in the cooling circuit ( 14 ), in particular an electrically controllable valve ( 46 ) and/or a radiator blower ( 24 ) associated with the radiator ( 16 ), and/or air flaps ( 20 ), are controlled via open-loop and/or closed-loop control in accordance with at least a first ( 55 ) and/or the at least one second ( 56 ) correction signal to obtain a specifiable volumetric flow of coolant and/or a specifiable coolant temperature.    
     
     
         10 . The method according to one of the preceding claims, 
 wherein the electronic control unit ( 52 ) controls—via open-loop and/or closed-loop control—the cooling capacity of the cooling circuit ( 14 ) and, in particular, the volumetric flow of coolant with consideration for at least one further parameter, in particular the pollutant emission of the engine ( 12 )