Method for adjusting a coolant flow by means of a heating cut-off valve

• US 7,421,984 B2
• Filed: 07/31/2004
• Issued: 09/09/2008
• Est. Priority Date: 08/14/2003
• Status: Expired due to Fees

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Inventors: Braun, Hans, Körber, Ralf, Weeber, Jochen, Timmann, Michael
• Primary Examiner(s): KAMEN, NOAH P
• Application Number:
  US10/568,189
• Publication Number:
  US 20070028862A1
• Time in Patent Office: 1,501 Days
• Field of Search: 123/41.01, 123/41.02, 123/41.08, 123/41.13, 123/41.29, 236/DIG.2, 237/9.A, 237/12.3 B
• US Class Current: 123/41.29
• CPC Class Codes: F01P 2007/146 using valves
• CPC Class Codes: F01P 2031/00 Fail safe
• CPC Class Codes: F01P 2031/32 Deblocking of damaged thermostat
• CPC Class Codes: F01P 2037/02 starting
• CPC Class Codes: F01P 2060/08 Cabin heater
• CPC Class Codes: F01P 7/16 by thermostatic control

Abstract

The invention relates to a method for actuating the valves in the three-way thermostat and in the heating cut-off valve of a cooling system. The valve setting in the cooling system is in this case selected such that during the warm-up phase of the engine, until the latter has reached its operating temperature, the coolant in the cooling ducts is brought to rest until the coolant temperature exceeds a predefined reference value.

Claims

1. A method for adjusting the coolant flow from the cooling ducts of an internal combustion engine into a heating heat exchanger with a cut-off valve, with the cooling ducts are additionally connected to an engine cooler via a three-way thermostat, including the steps of interrupting the coolant flow into the heating heat exchanger by the cut-off valve if the temperature of the coolant is below a predefined reference temperature (Ref21a, Ref1b, Ref2Min), and the coolant flow in the combustion ducts is thus stopped;

after a first reference temperature (Ref1b) as a preliminary threshold is exceeded, temporarily opening the cut-off valve, so that a wax pellet in the three-way thermostat is pre-heated; and

the cut-off valve is subsequently closed again until the coolant temperature has reached a second, higher reference value (Ref1a) as an operating threshold.

2. The method as claimed in claim 1, wherein if the temperature of the coolant in a lower temperature range between a lower reference temperature (Ref2Min) and an upper reference temperature (Ref2Max) and a load-dependent, calculated cooling water target temperature simultaneously falls below a third reference value (Ref3), the coolant flow in the cooling ducts of the internal combustion engine is started up by correspondingly opening the cut-off valve or a related valve in the three-way thermostat.

3. The method as claimed in claim 1, wherein the coolant flow is started up by correspondingly opening the cut-off valve or a related valve in the three-way thermostat if the calculated, load-dependent coolant target temperature exceeds a comparison value.

4. A method for adjusting the coolant flow from the cooling ducts of an internal combustion engine into a heating heat exchanger with a cut-off valve, with the cooling ducts are additionally connected to an engine cooler via a three-way thermostat, including the steps of interrupting the coolant flow into the heating heat exchanger by the cut-off valve if the temperature of the coolant is below a predefined reference temperature (Ref21a, Ref1b, Ref2Min), and the coolant flow in the combustion ducts is thus stopped;

and, if the temperature of the coolant in a lower temperature range between a lower reference temperature (Ref2Min) and an upper reference temperature (Ref2Max) and a load-dependent, calculated cooling water target temperature simultaneously falls below a third reference value (Ref3), the coolant flow in the cooling ducts of the internal combustion engine is started up by correspondingly opening the cut-off valve or a related valve in the three-way thermostat.

5. A method for adjusting the coolant flow from the cooling ducts of an internal combustion engine into a heating heat exchanger with a cut-off valve, including the steps of interrupting the coolant flow into the heating heat exchanger by the cut-off valve if the temperature of the coolant is below a predefined reference temperature, and the coolant flow in the combustion ducts is thus stopped;

and, the coolant flow is started up by correspondingly opening the cut-off valve if the calculated, load-dependent coolant target temperature exceeds a comparison value.