# US 7,406,929 B2 · Cooling circuit of an internal combustion engine comprising a low-temperature radiator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,406,929 B2 - Document ID: US7406929B2 - Status: Granted - Kind: B2 - Application number: 10/542,371 - Filed: 2004-01-14 - Published: 2006-11-16 - Granted: 2008-08-05 - Earliest claimed: 2003-01-16 - Assignees: Behr GmbH & Co. - Inventors: Klaus Hassdenteufel; Stefan Rogg - Web page: https://patentgrep.com/patent/US7406929B2 ## CPC - F28F 9/0234: {having a second heat exchanger disposed there within, e.g. oil cooler} - F01P 3/20: Cooling circuits not specific to a single part of engine or machine (F01P3/22 takes precedence) - F01P 7/165: {characterised by systems with two or more loops} - F01P 3/18: Arrangements or mounting of liquid-to-air heat-exchangers (such arrangements on cylinders or cylinder heads F01P3/04; relative to vehicles B60K11/04) - F01P 2003/185: {arranged in parallel} - F01P 2007/168: {By varying the cooling capacity of a liquid-to-air heat-exchanger} - F01P 2050/06: using liquid-to-liquid heat exchangers - F01P 2060/045: for transmissions - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - F01P: COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES (arrangements in connection with cooling of propulsion units in vehicles B60K11/00; heat-transfer, heat-exchange or heat-storage materials C09K5/00; {cooling of gas-turbine engines F02C7/12}; heat exchange in general, radiators F28) ## Abstract The invention relates to a cooling circuit of an internal combustion engine of motor vehicles, comprising a main cooling circuit that encompasses a section located upstream of the radiator, a main radiator, a radiator return path, a coolant pump, a main thermostat, and a bypass or short circuit which is disposed between the main thermostat and the coolant pump. Said cooling circuit further comprises a low-temperature circuit encompassing a low-temperature radiator, a low-temperature radiator return path, a valve unit, and an additional heat exchanger. ## Claims ### Claim 1 A cooling circuit of an internal combustion engine of a motor vehicle having a main cooling circuit, comprising: a main radiator (5a), a section (3) located upstream of the radiator, a radiator return flow section (8), a coolant pump (10), a main thermostat (2) and a bypass or short circuit (4) between the main thermostat (2) and the coolant pump (10), and a low-temperature circuit, comprising a low-temperature radiator (5b), a low-temperature radiator return flow section (11), a valve unit, and an additional heat exchanger, wherein the low-temperature radiator (5b) is connected in parallel with the main radiator (5a); wherein the main thermostat (2) is arranged in the section (3) located upstream of the radiator; and wherein the valve unit is embodied as a mixing thermostat (14) with a first inlet, a second inlet, and one outlet, wherein the first inlet and the outlet are connected into the return flow section (11) of the low-temperature radiator (5b), and the second inlet is connected to the main thermostat (2). ### Claim 2 (depends on 1) The cooling circuit as claimed in claim 1, wherein the additional heat exchanger is embodied as a gear oil radiator (13). ### Claim 3 (depends on 1) The cooling circuit as claimed in claim 1, wherein a warming up thermostat (16) is connected between the second inlet and the main thermostat (2). ### Claim 4 A cooling circuit of an internal combustion engine of a motor vehicle having a main cooling circuit, comprising: a main radiator (5a), a section (3) located upstream of the radiator, a radiator return flow section (8), a coolant pump (10), a main thermostat (2) and a bypass or short circuit (4) between the main thermostat (2) and the coolant pump (10), and a low-temperature circuit, comprising a low-temperature radiator (5b), a low-temperature radiator return flow section (11), a valve unit, and an additional heat exchanger, wherein the low-temperature radiator (5b) is connected in parallel with the main radiator (5a); wherein the main thermostat (2) is arranged in the section (3) located upstream of the radiator; and wherein the valve unit is embodied as a warming up thermostat (16) which is connected between the return flow section (11) of the low-temperature radiator (5b) and the bypass or short circuit (4). ### Claim 5 A cooling circuit of an internal combustion engine of a motor vehicle having a main cooling circuit, comprising: a main radiator (5a), a section (3) located upstream of the radiator, a radiator return flow section (8), a coolant pump (10), a main thermostat (2) and a bypass or short circuit (4) between the main thermostat (2) and the coolant pump (10), and a low-temperature circuit, comprising a low-temperature radiator (5b), a low-temperature radiator return flow section (11), a valve unit, and an additional heat exchanger, wherein the low-temperature radiator (5b) is connected in parallel with the main radiator (5a); wherein the main thermostat (2) is arranged in the radiator return flow section (8); and wherein the valve unit is embodied as a mixing thermostat (4) with a first inlet, a second inlet, and one outlet, wherein the first inlet and the outlet are connected into the return flow section (11) of the low-temperature radiator (5b), and the second input is connected to the section (3) located upstream of the radiator. ### Claim 6 (depends on 5) The cooling circuit as claimed in claim 5, wherein a warming up thermostat (16) is connected between the section (3) located upstream of the radiator and the second inlet. ### Claim 7 A cooling circuit of an internal combustion engine of a motor vehicle having a main cooling circuit, comprising: a main radiator (5a), a section (3) located upstream of the radiator, a radiator return flow section (8), a coolant pump (10), a main thermostat (2) and a bypass or short circuit (4) between the main thermostat (2) and the coolant pump (10), and a low-temperature circuit, comprising a low-temperature radiator (5b), a low-temperature radiator return flow section (11), a valve unit and an additional heat exchanger, wherein the low-temperature radiator (5b) is connected in parallel with the main radiator (5a); wherein the main thermostat (2) is arranged in the radiator return flow section (8); and wherein the valve unit is embodied as a warming up thermostat (16) which is connected into the return flow section (11) of the low-temperature radiator (5b). ### Claim 8 A coolant radiator of a cooling circuit of an internal combustion engine of a motor vehicle, comprising: a pipe/rib block, a coolant inlet box (51, 62) with a coolant inlet (53, 63), and a collecting box (52, 64) with a coolant connection to the pipe/rib block, wherein the pipe/rib block has a main region (50a, 61a) and a low-temperature region (50b, 61b), and coolant outlets for a coolant main flow and a coolant partial flow; wherein the main region (50a, 61b) and the low-temperature region (50b, 61b) are connected in parallel; and wherein a dividing element (54, 66) which divides the pipe/rib block into the main region (50a, 61a) and the low-temperature region (50b, 61b), and divides the collecting box (52, 64) into a main chamber (55, 67) and a secondary chamber (56, 68) is arranged in the collecting box (52, 64). ### Claim 9 (depends on 8) The coolant radiator as claimed in claim 8, wherein the dividing element is embodied as a sealed dividing wall (54, 66). ### Claim 10 (depends on 8) The coolant radiator as claimed in claim 8, wherein the dividing element is embodied as an unsealed dividing wall with a throttle point. ### Claim 11 (depends on 8) The coolant radiator as claimed in claim 8, wherein the dividing element is embodied as a dividing wall with a valve. ### Claim 12 (depends on 8) The coolant radiator as claimed in claim 8, wherein an additional heat exchanger is integrated into, or with, the collecting box (52, 64), and a partial stream of coolant can flow through it. ### Claim 13 (depends on 8) The coolant radiator as claimed in claim 8, wherein an open longitudinal dividing wall (57) is arranged in the main chamber (55) and forms a mixing chamber (58) in which the additional heat exchanger (59) is arranged. ### Claim 14 (depends on 13) The coolant radiator as claimed in claim 13, wherein a mixing thermostat (60), which has a coolant connection to the secondary chamber (56) and the mixing chamber (58) and can be connected to the cooling circuit, is integrated into the mixing chamber (58). ### Claim 15 (depends on 12) The coolant radiator as claimed in claim 12, wherein the additional heat exchanger (72) is attached to the collecting box (64) by a mounting plate (71). ### Claim 16 (depends on 15) The coolant radiator as claimed in claim 15, wherein a mixing chamber (69) is arranged in the region of the secondary chamber (68) and a mixing thermostat (70), wherein the mixing thermostat has a coolant connection to the secondary chamber (68) and to the mixing chamber (69) and can be connected to the cooling circuit is integrated into the mixing chamber (69), and wherein the additional heat exchanger (72) has a coolant connection to the mixing chamber (69) and the main chamber (67). ### Claim 17 (depends on 12) The coolant radiator as claimed in claim 12, wherein the additional heat exchanger is a gear oil radiator (59, 72). ### Claim 18 A coolant radiator of a cooling circuit of an internal combustion engine of a motor vehicle, comprising: a pipe/rib block, a coolant inlet box (51, 62) with a coolant inlet (53, 63), and a collecting box (52, 64) with a coolant connection to the pipe/rib block, wherein the pipe/rib block has a main region (50a, 61a) and a low-temperature region (50b, 61b) and coolant outlets for a coolant main flow and a coolant partial flow; wherein the main region (50a, 61b) and the low-temperature region (50b, 61a) are connected in parallel; and wherein a partial stream of coolant, which makes up approximately 4% to 15% of an entire stream of coolant, can flow through the low-temperature region (50b, 61b).