Engine system having thermostat

Abstract

An engine system may include an engine configured to generate a torque, a coolant temperature sensor configured to detect a temperature of a coolant circulating the engine, an atmosphere temperature sensor configured to detect an atmosphere temperature, a thermostat disposed on a coolant line to regulate a coolant passage, an operating portion disposed in the thermostat and electrically regulating the coolant passage, and a control portion that variably controls the coolant temperature. The operating portion is operated according to the coolant temperature transmitted from the coolant temperature sensor, the atmosphere temperature transmitted from the atmosphere sensor, and/or an engine load.

What is claimed is: 
     
         1 . An engine system, comprising:
 an engine that is configured to generate a torque;   a coolant temperature sensor that is configured to detect a temperature of a coolant circulating the engine;   an atmosphere temperature sensor that is configured to detect an atmosphere temperature;   a thermostat that is disposed on a coolant line to regulate a coolant passage;   an operating portion that is disposed in the thermostat and electrically regulates the coolant passage; and   a control portion that variably controls the coolant temperature that the operating portion is operated according to the coolant temperature transmitted from the coolant temperature sensor and the atmosphere temperature transmitted from the atmosphere sensor.   
     
     
         2 . The engine system of  claim 1 , further comprising a cooling fan that is disposed near a radiator, wherein the control portion variably controls an operating timing of the cooling fan according to the coolant temperature transmitted from the coolant temperature sensor and the atmosphere temperature transmitted from the atmosphere sensor. 
     
     
         3 . The engine system of  claim 1 , wherein the control portion determines a load of the engine by using a driving information of the engine and characterizes the load of the engine into a low load, a middle load, and a high load. 
     
     
         4 . The engine system of  claim 3 , wherein the control portion variably controls the coolant temperature that the operating portion is operated depending on the load of the engine. 
     
     
         5 . The engine system of  claim 4 , wherein when the load of the engine is high, the coolant temperature that the operating portion is operated is lower than that when the load of the engine is low. 
     
     
         6 . The engine system of  claim 4 , wherein the coolant temperature that the operating portion is operated at the high load is lower than those at the middle load and at the low load. 
     
     
         7 . The engine system of  claim 4 , wherein the coolant temperature that the operating portion is operated at the low load is higher than those at the middle load and at the high load. 
     
     
         8 . The engine system of  claim 1 , wherein when the atmosphere temperature is high, the coolant temperature that the operating portion is operated is lower than that when the atmosphere temperature is low.