Patent Application
20070113801
The present invention relates generally to engines and more specifically to an aftercooler thermostat housing system for such engines.
In a conventional cooling system for an internal combustion engine, the coolant is circulated by a circulating pump through the engine block, through the cylinder heads, eventually through the intake manifold. In an automobile, or other land vehicle, the coolant flows through a radiator. Most marine engines do not have a radiator. In a marine engine having an open loop cooling system, sea water supplied by a sea water pump is used to directly cool the engine and is then discharged overboard.
Other engines have closed loop cooling systems. In a closed loop cooling system, an engine coolant circulates through the engine and then through a heat exchanger.
In closed loop cooling systems, the flow of engine coolant through the heat exchanger is controlled by a thermostat on the engine block of the engine When the engine and engine coolant are cold, the thermostat is closed so that coolant does not pass through the heat exchanger. With the thermostat closed, a small portion of engine coolant flows through a bypass and returns a limited amount of coolant to the circulating pump, so that there is a sufficient engine coolant flow through the engine block while the system is warming up. While a limited amount of engine coolant is adequate when the engine warms up slowly, problems can occasionally exist if the operator runs the engine wide open before the engine and coolant have warmed up. Under these conditions, coolant flow through the engine bypass before the thermostat opens might not provide sufficient cooling. This can be critical because wide open operation can quickly lead to hot spots in an engine. The present invention addresses such a need.
An aftercooler thermostat housing for an engine is disclosed. The housing system comprises a housing and a thermostat within the housing. The housing system further includes a bypass system for providing a connection to allow an engine coolant to flow to the aftercooler system if the engine coolant temperature is below a first predetermined temperature. The bypass system allows for the engine coolant to flow through a heat exchanger which is part of the aftercooler system if the temperature of the coolant is above the first predetermined temperature. A low temperature aftercooler (LTA) thermostat housing system achieves the necessary heat rejection for the engine via the heat exchanger and achieves low temperature aftercooling using the heat exchanger.
The present invention relates generally to engines and more specifically to an aftercooler thermostat housing system for such engines. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.
A low temperature aftercooler (LTA) thermostat housing system is disclosed for an engine in order to achieve the necessary heat rejection for the engine via the heat exchanger and to achieve low temperature aftercooling using the heat exchanger.
The external system 12 comprises an oil cooler 28, an aftercooler 30, a heat exchanger 32 and a low temperature aftercooler (LTA) thermostat housing system 34 in accordance with the present invention. The aftercooler 30 cools compressed air from the engine. It is after the turbo in the air flow stream. The oil cooler 28 cools gear oil. The LTA thermostat housing system 34 is mounted external to the base engine. The LTA thermostat housing system 34 regulates the volume of external water flow through the low temperature aftercooler 30 and the heat exchanger 32. The heat exchanger can be a variety of types dependent on the engines used. For example, the heat exchanger could be a radiator, a skin cooler, a keel cooler and the like and its use would be within the spirit and scope of the present invention. The LTA thermostat housing system 34 piping is also designed to regulate the volume of bypass water flow.
Referring to
When the engine coolant is at a predetermined temperature or below that temperature, the coolant flows into the thermostat housing system 34 at the intake 42, and out from the thermostat housing system 34 through the engine output 36. When the engine coolant is above a predetermined temperature, the coolant flows into the thermostat housing system 34 at the intake 42. The bypass system 44 then directs the coolant to flow out of the thermostat housing system 34 from the heat exchanger output 38. After the coolant has passed through the heat exchanger 32, then the coolant returns to the thermostat housing system 34 via the heat exchanger input 40. The coolant is then directed by the bypass mechanism 44 towards the engine 11, out of engine output 36.
Accordingly, the thermostat housing system 34 maintains the temperature of the engine 11 at the appropriate levels by regulating the coolant temperature from the aftercooler system 12 thereby controlling the engine 11. In so doing, the engine 11 is better protected from heat related sources.
Advantages
The low temperature aftercooler (LTA) thermostat housing has the following advantages:
Constant change in pressure at a fully closed and open thermostat
Relatively constant intake manifold temperature at all prop curve loads and engine speeds.
Small compact, universal mounting
Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.
