Cooling apparatus for internal combustion engine

A cooling apparatus for an internal combustion engine, comprising:

• an oil warmer, which performs heat exchange between coolant of the engine and lubricant of a transmission;
• an internal passage, which is provided in the engine and through which the coolant flows;
• a warmer passage, which causes coolant that has flowed out through an outlet of the internal passage to flow into an inlet of the internal passage, wherein the oil warmer is connected to a middle section of the warmer passage;
• a water pump, which is configured to cause the coolant in the internal passage and the warmer passage to flow;
• and
• a thermostat, which is configured to regulate an amount of coolant that flows into the oil warmer, wherein
• the thermostat includes
• a valve member, which is configured to close the warmer passage,
• a body, and
• a plurality of types of wax, which are accommodated in the body and separated from each other,
• the thermostat is configured to determine a degree of opening of the valve member in accordance with amounts of expansion of the respective types of wax caused by melting of the respective types of wax,
• the body contacts one of the lubricant and the coolant in the warmer passage,
• the types of wax include
• a first wax, which melts at a first temperature, and
• a second wax, which melts at a second temperature which is higher than the first temperature,
• the thermostat is located on an upstream side of the oil warmer in the warmer passage, and
• the cooling apparatus further comprises a branch passage, which is connected to a part of the warmer passage that is located on an upstream side of the thermostat and is separated from the thermostat.

A cooling apparatus for an internal combustion engine, comprising:

• an oil warmer, which performs heat exchange between coolant of the engine and lubricant of a transmission;
• an internal passage, which is provided in the engine and through which the coolant flows;
• a warmer passage, which causes coolant that has flowed out through an outlet of the internal passage to flow into an inlet of the internal passage, wherein the oil warmer is connected to a middle section of the warmer passage;
• a water pump, which is configured to cause the coolant in the internal passage and the warmer passage to flow;
• and
• a thermostat, which is configured to regulate an amount of coolant that flows into the oil warmer, wherein
• the thermostat includes
• a valve member, which is configured to close the warmer passage,
• a body, and
• a plurality of types of wax, which are accommodated in the body and separated from each other,
• the thermostat is configured to determine a degree of opening of the valve member in accordance with amounts of expansion of the respective types of wax caused by melting of the respective types of wax,
• the body contacts one of the lubricant and the coolant in the warmer passage,
• the types of wax include
• a first wax, which melts at a first temperature, and
• a second wax, which melts at a second temperature which is higher than the first temperature,
• warmer passage is configured such that, in a closed state of the thermostat, the coolant that has reached the thermostat is prevented from flowing out to a downstream side of the thermostat,
• the coolant in the warmer passage contacts the body of the thermostat,
• at least a section of a part of the warmer passage in which the thermostat is provided is arranged to contact the oil warmer, and
• when the engine is started from a state in which a temperature of the coolant is lower than or equal to 30° C., the first wax starts to melt during a period when the temperature of the coolant at an upstream side of the thermostat is lower than or equal to the temperature of the lubricant in the oil warmer.