Cooling circuit for an internal combustion engine

• US 20050205683A1
• Filed: 02/18/2003
• Published: 09/22/2005
• Est. Priority Date: 03/08/2002
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schmitt, Manfred, Windisch, Herbert, Kaefer, Oliver, Mann, Karsten
• Application Number:
  US10/507,038
• Publication Number:
  US 20050205683A1
• Time in Patent Office: Days
• US Class Current: 237/12
• CPC Class Codes: F01P 2003/024 Cooling cylinder heads
• CPC Class Codes: F01P 2005/105 Using two or more pumps
• CPC Class Codes: F01P 2007/146 using valves
• CPC Class Codes: F01P 2037/02 starting
• CPC Class Codes: F01P 2060/08 Cabin heater
• CPC Class Codes: F01P 7/162 by cutting in and out of pumps
• CPC Class Codes: F01P 7/165 characterised by systems with two or more loops

Abstract

A cooling circuit for an internal combustion engine includes a first coolant circuit and a second coolant circuit, the cooling circuit being able to be operated by a distributor so that the internal combustion engine reaches its operating temperature as quickly as possible, and a heat exchanger used to heat the vehicle interior is operational as quickly as possible. The return channel from the second coolant circuit is connectable to either the return channel or the flow channel of the first coolant circuit.

Claims

1-15. -15. (canceled)

16. A cooling circuit for an internal combustion engine, comprising:

a first external coolant circuit including a first flow channel, a first return channel, and a main coolant pump, wherein the first external coolant circuit supplies waste heat from the internal combustion engine to a radiator, and wherein the first flow channel is connected to the cylinder head of the internal combustion engine;

a second external coolant circuit including a second flow channel, a second return channel, and an auxiliary coolant pump, wherein the second external coolant circuit supplies waste heat from the internal combustion engine to a heat exchanger, and wherein the second flow channel is connected to a cylinder head of the internal combustion engine; and

a distributor having a first position and a second position, wherein in the first position the distributor connects the first return channel to the second return channel, and wherein in the second position the distributor connects the second return channel to the first flow channel and the auxiliary coolant pump delivers coolant from the second return channel to the first flow channel, thereby bypassing an engine block of the internal combustion engine.

17. The cooling circuit as recited in claim 16, further comprising a bypass line provided in the first coolant circuit to bypass the radiator.

18. The cooling circuit as recited in claim 17, wherein the bypass line is selectively opened and closed depending on temperature.

19. The cooling circuit as recited in claim 17, wherein the distributor in the second position connects the second return channel to the first bypass line.

20. The cooling circuit as recited in claim 18, wherein the auxiliary coolant pump is controlled as a function of temperature.

21. A method for controlling a cooling circuit for an internal combustion engine, comprising:

detecting a temperature of the internal combustion engine;

deactivating a main coolant pump and an auxiliary coolant pump, and setting a distributor to a first position, when the temperature of the internal combustion engine is less than a first threshold value;

deactivating the main coolant pump and activating the auxiliary coolant pump, and setting the distributor to the first position, when the temperature of the internal combustion engine is at least equal to the first threshold value and less than a second threshold value; and

activating the main coolant pump and deactivating the auxiliary coolant pump, and setting the distributor to a second position, when the temperature of the internal combustion engine is at least equal to the second threshold value.

22. The method as recited in claim 21, wherein the main coolant pump is activated, the auxiliary coolant pump is deactivated, and the distributor is set to the first position, when a power output of the internal combustion engine exceeds a threshold limit value.

23. The method as recited in claim 22, wherein the power output of the internal combustion engine is calculated according to the following formula:

Power output=M_eng×

n_eng,

wherein M_eng is the torque output by the internal combustion engine, and n_eng is the rotational speed of the internal combustion engine

24. The method as recited in claim 21, wherein the main coolant pump is activated, the auxiliary coolant pump is deactivated, and the distributor is set to the first position, when one of a torque output of the internal combustion engine and a rotational speed of the internal combustion engine exceeds a threshold limit value.

25. The method as recited in claim 21, wherein the main coolant pump is activated, at the latest, after a predetermined maximum deactivation time has been exceeded.

26. The method as recited in claim 25, wherein the predetermined maximum deactivation time is dependent on a coolant temperature at the time the engine is started.

27. The method as recited in claim 21, wherein the auxiliary coolant pump is also activated as a function of the temperature in the second flow channel.

28. The method as recited in one of claim 21, wherein the auxiliary coolant pump is also activated as a function of a component temperature of the internal combustion engine.

29. The method as recited in claim 28, wherein the component temperature of the internal combustion engine is a temperature inside a cylinder head of the internal combustion engine.