Automatic temperature and humidity regulation – Thermostatic – With indicator or alarm
Reexamination Certificate
2000-02-10
2001-05-22
Wayner, William (Department: 3753)
Automatic temperature and humidity regulation
Thermostatic
With indicator or alarm
C073S116070, C123S041150, C165S011100
Reexamination Certificate
active
06234399
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a method for determining malfunctioning of a thermostatic valve, which determines the division of an amount of coolant exiting an internal combustion engine of a motor vehicle into a portion which moves through a coolant radiator, and a portion returning to the internal combustion engine while bypassing the coolant radiator, and to devices for executing the method.
BACKGROUND OF THE INVENTION
Cooling systems of motor vehicle engines are customarily equipped with a thermostatic valve, which controls the distribution of the amounts of a coolant exiting the internal combustion engine and flowing through a coolant radiator back to the internal combustion engine or, bypassing the coolant radiator, directly through a bypass back into the engine. It is attempted by means of this thermostatic valve to maintain the operating temperature of the internal combustion engine at as constant (high) a temperature as possible after it has warmed up.
Thermostatic valves of this type have achieved a very high standard of quality because of long years of development, so that they fail only rarely. Still, there is the need for monitoring the ability of the thermostatic valve to function.
OBJECT AND SUMMARY OF THE INVENTION
The object of the invention is to determine whether a thermostatic valve is malfunctioning because the valve has not opened or closed as required by engine operating conditions. In accordance with the invention, this is done without intervention with the thermostatic valve and only on the basis of an evaluation of detected temperatures, in particular of those temperatures influenced by the thermostatic valve.
In connection with a first embodiment, the actual temperature of the internal combustion engine and the actual temperature at the outlet of the coolant radiator are measured and combined, and the combinations are compared with stored combinations of these temperatures for detecting a malfunction of the thermostatic valve and for generating a signal representing the malfunction.
The invention proceeds from the realization that the engine temperature and the coolant temperature at the radiator outlet have defined relationships with each other, if the thermostatic valve functions normally. If, however, temperature combinations are detected which could not occur under normal functioning, it is possible to directly deduce from this that a malfunction of the thermostatic valve exists.
In connection with a second embodiment, the actual temperature of the internal combustion engine and the actual temperature at the outlet of the coolant radiator are measured, and states and changes in state of the detected temperatures are combined and compared in order to detect a malfunction of the thermostatic valve from this and to generate a signal representing the malfunction. This attainment, too, proceeds from the realization that certain temperature states or changes in those states cannot occur, if the thermostatic valve operates normally, so that, if these states or changes in states nevertheless do appear, it is possible to deduce a malfunction of the thermostatic valve.
In further development of the invention it is provided that the ambient temperature is detected and is also taken into consideration in the combinations. It is possible to refine the evaluation by means of including the ambient temperature in the measurement and evaluation and possibly to detect not quite unambiguous combinations of temperatures clearly as a malfunction or a normal function.
In a device for executing the first method, a memory is provided for receiving a multitude of combinations of temperatures of the internal combustion engine and temperatures of the coolant at the outlet of the coolant radiator, and preferably also of the ambient temperature, means for detecting the actual temperature of the internal combustion engine and means for detecting the actual temperature of the coolant at the outlet of the coolant radiator, and preferably means for detecting the ambient temperature, means for forming the combinations of the measured temperatures, means for comparing the stored combinations with the combinations of the measured temperatures, and means for producing a signal representing a malfunction of the thermostatic valve.
In a device for executing the second method, means are provided for detecting the actual temperature of the internal combustion engine and means for detecting the actual temperature of the coolant at the outlet of the coolant radiator, and preferably means for detecting the ambient temperature, whose outputs are connected to a logic circuit which, as a function of the states and changes in the states of the detected temperatures generates a signal which represents a possible malfunction of thermostatic valve.
Further characteristics and advantages of the invention ensue from the following description of exemplary embodiments with reference to the accompanying drawings.
REFERENCES:
patent: 4069712 (1978-01-01), Armstrong et al.
patent: 4804139 (1989-02-01), Bier
patent: 5467745 (1995-11-01), Hollis
patent: 5526871 (1996-06-01), Musser et al.
patent: 44 26 494 A 1 (1994-07-01), None
patent: 197 55 859 A1 (1997-12-01), None
German Search Report dated 27 Dez. 1999 (4 pages).
Behr Thermotronik GmbH & Co.
Kennedy Covington Lobdell & Hickman L.L.P.
Wayner William
LandOfFree
Method and means for determining malfunctioning of a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and means for determining malfunctioning of a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and means for determining malfunctioning of a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2510385