Internal-combustion engines – Cooling – Automatic coolant flow control
Reexamination Certificate
1999-06-09
2001-01-30
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Cooling
Automatic coolant flow control
C123S041440
Reexamination Certificate
active
06178928
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a cooling control system for an internal combustion engine and more particularly to a total cooling control system employing an electric water pump, various temperature sensors, a radiator flow control valve, a radiator fan motor and a controller to control the cooling system to maintain an engine operating temperature within a narrow range around a target temperature.
2. Description of Related Art
Conventional internal combustion cooling systems generally employ a mechanical water pump which is operated based on engine speed, a thermostat, and a radiator to maintain the engine temperature within a safe operating temperature range. However, since the speed of the mechanical water pump is directly related to the engine rpm, at low engine rpm and high engine load, the speed of the mechanical water pump may limit the ability of the cooling system to dissipate the required heat from the engine. This condition can lead to the temperature of the engine exceeding the controllable range of the thermostat. In addition, at high engine rpm and low load conditions, the capacity of the water pump may exceed the necessary cooling requirements and energy may be wasted due to circulating excess fluid. This wasted energy represents a potential fuel savings.
With the conventional mechanical water pump and thermostat, generally the set point for the engine operating temperature is fixed. With a fixed operating temperature, the cooling system may not be tuned to optimize emission and power based on engine load.
Accordingly, a need exists to provide a total cooling control system to maintain the engine operating temperature within a narrow range around a target temperature with the engine target temperature and mass flow rate through the engine being a direct function of the he at released and an indirect function of engine load.
SUMMARY OF THE INVENTION
An object of the present invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is obtained by providing an engine cooling system including an engine; a radiator assembly including a radiator and a fan driven by an electric fan motor, a coolant circulation circuit interconnecting the engine and t he radiator for circulating coolant; a by-pass circuit connected to the coolant circulation circuit so that coolant may by-pass the radiator; an electrically powered variable speed coolant pump disposed in the coolant circulation circuit to pump coolant through the coolant circulation circuit; control valve structure constructed and arranged to control mass flow of coolant through the radiator; an engine temperature sensor to detect a temperature of engine coolant; a radiator temperature sensor to detect a temperature of air exiting the radiator or a temperature of coolant at an outlet of the radiator; and a controller operatively connected with the electric fan motor, the coolant pump, the control valve structure, the engine temperature sensor, and the radiator temperature sensor. The controller selectively controls (1) the control valve structure, (2) operation of the coolant pump based on signals received from the engine temperature sensor and (3) operation of the electric fan motor based on a signal received from the radiator temperature sensor, thereby controlling an operating temperature of the engine to approach a target operating temperature as a direct function of heat released, without monitoring actual speed or load of the engine.
In accordance with another aspect of the invention, a method of controlling an operating temperature of an engine is provided. The engine has a cooling system including a radiator assembly including a radiator and a fan driven by an electric fan motor; a coolant circulation circuit interconnecting the engine and the radiator for circulating coolant; a by-pass circuit connected to the coolant circulation circuit so that coolant may by-pass the radiator; an electrically powered variable speed coolant pump disposed in the coolant circulation circuit to pump coolant through the coolant circulation circuit; control valve structure constructed and arranged to control mass flow of coolant through the radiator; an engine temperature sensor to detect a temperature of engine coolant; a radiator temperature sensor to detect a temperature of air exiting the radiator or a temperature of coolant at an outlet of the radiator; and controller operatively connected the electric fan motor, the coolant pump, the control valve structure, the engine temperature sensor, and the radiator temperature sensor. The method includes determining the temperature of engine coolant and comparing the coolant temperature with a target engine coolant temperature. Based on a difference between the coolant temperature and the target engine coolant temperature, the control valve structure is operated and a speed of the coolant pump is controlled to control a mass flow rate of coolant though the radiator, thereby adjusting the operating temperature of the engine, without determining engine load and speed. An actual temperature of air exiting the radiator or of coolant at an outlet of the radiator is determined and compared to a target temperature. Based on a difference between the actual temperature and the target temperature, a speed of the electric fan motor is controlled to improve thermal performance of the radiator.
Other objects, features and characteristic of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.
REFERENCES:
patent: 1284177 (1918-11-01), Camden
patent: 1576833 (1926-03-01), Larsen
patent: 1911522 (1933-05-01), McIntyre
patent: 1941587 (1934-01-01), Stone et al.
patent: 1992795 (1935-02-01), Young
patent: 2162152 (1939-06-01), Wulle
patent: 2286398 (1942-06-01), Young
patent: 2420436 (1947-05-01), Mallory
patent: 2606539 (1952-08-01), Field, Jr.
patent: 2631543 (1953-03-01), Richmond
patent: 2697986 (1954-12-01), Meagher, Jr.
patent: 2953993 (1960-09-01), Strickland et al.
patent: 3096818 (1963-07-01), Evans et al.
patent: 3164096 (1965-01-01), Hallerback
patent: 3444845 (1969-05-01), Scheiterlein
patent: 3719436 (1973-03-01), McFarlin
patent: 3795274 (1974-03-01), Fieni
patent: 3999598 (1976-12-01), Fehr et al.
patent: 4061187 (1977-12-01), Rajasekaran et al.
patent: 4333797 (1982-06-01), Nishizawa
patent: 4369738 (1983-01-01), Hirayama
patent: 4381736 (1983-05-01), Hirayama
patent: 4423705 (1984-01-01), Morita et al.
patent: 4434749 (1984-03-01), Morita et al.
patent: 4459087 (1984-07-01), Barge
patent: 4461246 (1984-07-01), Clemente
patent: 4475485 (1984-10-01), Sakakibara et al.
patent: 4480551 (1984-11-01), LoFiego
patent: 4489680 (1984-12-01), Spokas et al.
patent: 4539942 (1985-09-01), Kobayashi et al.
patent: 4545333 (1985-10-01), Nagumo et al.
patent: 4546742 (1985-10-01), Sturges
patent: 4557223 (1985-12-01), Gueyen
patent: 4567858 (1986-02-01), Hayashi
patent: 4580531 (1986-04-01), N'Guyen
patent: 4615599 (1986-10-01), Kataoka et al.
patent: 4616599 (1986-10-01), Taguchi et al.
patent: 4620509 (1986-11-01), Crofts
patent: 4685513 (1987-08-01), Longhouse et al.
patent: 4688998 (1987-08-01), Olsen et al.
patent: 4691668 (1987-09-01), West
patent: 4702306 (1987-10-01), Herzog
patent: 4726324 (1988-02-01), Itakura
patent: 4726325 (1988-02-01), Itakura
patent: 4744335 (1988-05-01), Miller
patent: 4753284 (1988-06-01), Krause et al.
patent: 4759316 (1988-07-01), Itakura
patent: 4768484 (1988-09-01), Scarselletta
patent: 4876492 (1989-10-01), Lester et al.
patent: 4930455 (1990-06-01), Creed et al.
patent: 4961404 (1990-10-01), Itakura et al.
patent: 5000257 (1991-03-01), Shinmura
patent: 5002019 (1991-03-01), Klaucke et al.
patent: 5021185 (1991-06-01), Mustakallio
Harris Katrina B.
Siemens Canada Limited
Wolfe Willis R.
LandOfFree
Internal combustion engine total cooling control system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Internal combustion engine total cooling control system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Internal combustion engine total cooling control system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2438879