Abstract:
The present invention provides a dual six-stroke self-cooling internal combustion engine which utilizes a turbo and a cooling cylinder to compress cool air onto the engine head and reduce the engine temperature. The present invention greatly reduces the size and the manufacture cost of the cooling equipments such as radiator and intercooler by cooling the power cylinder from within. In addition, the present invention slightly increases the fuel efficiency and reduces the exhaust temperature.

Description:
BACKGROUND OF THE INVENTION 
   Cooling equipment is one essential component for internal combustion engine as the engine temperature directly affects the overall durability, performance, and manufacture cost. My research has led me in the direction of providing an unlimited compression ratio cooling cylinder combined with a charge-intake to reduce the engine temperature. This self-cooling internal combustion engine requires a basic unit of two four-cycle power cylinders and one cooling cylinder and a charge-intake device to utilize energy of power stroke and exhaust to cool down the temperature of the engine head from within after combustion process of each power stroke completes. Said two power cylinders are arranged with 180 degree of crankshaft rotation apart and said cooling cylinder is trailing the primary power cylinder by approximately 90 degree of crankshaft rotation; said cooling cylinder initiate a flow of compressed cool air into each power cylinder approximately 60 degree of crankshaft rotation after ignition of each power cylinder. The working medium within the power cylinder is approximately over 2000 degree for gasoline right after the ignition, when the compressed cool air flows into the power cylinder, the compressed cool air is blown up onto the inner surface of the engine head, creating a cool air barrier beneath the inner surface of the engine head and absorbing the heat of the combustion, therefore the engine head temperature and exhaust temperature is greatly reduced. 
   The prior art shows that various inventors have suggested a structure consisting of two four-cycle power cylinders and one air-fuel charging cylinder; one representative of such structure is U.S. Pat. No. 4,202,300, the major differences between these types of engines and the present invention are that the charging cylinder of the prior art requires variable volume and fuel input, and the objective is to force additional air-fuel mixture into the power cylinder before the ignition of power cylinders, these types of engines utilize the charging cylinder to increase the amount of air-fuel mixture in each combustion process thereby increasing the engine temperature and power output. Another significant difference is that the size of the cooling cylinder of the present invention is approximately the same as that of the power cylinders for cooling purpose while other prior art has a relatively small charging cylinder for air-fuel compressing purpose. 
   Another type of engine structure shown in the prior art has one primary cylinder connected to one secondary power cylinder, even though the secondary power cylinder only has air input, the objective of this type of engine is to prolong the combustion process and increase the fuel economy. The major difference is that the basic structure of the present invention is based on a concept of dual six-stroke operation, and the cooling cylinder only provides cooling effect to the engine, the cooling cylinder cannot provide any power output while the objective of the prior art is to generate power output from both primary and secondary power cylinders. 
   The most preferable type of charge-intake of the present invention is a turbo type. The exhaust ports of the primary power cylinder and the secondary power cylinder are connected to the input side of the turbo, while the compressor discharge side of the turbo is connected to the cooling cylinder; this is also another objective to the present invention to utilize energy of the exhaust to cool down the engine from within, this embodiment can possibly eliminate the needs for additional cooling equipments such as radiators and intercoolers, therefore its applications can extend to the vehicle engines running on severe condition territory such as desert. Since the need of radiator is eliminated, the engine reliability under severe weather condition is greatly improved. 
   It is also possible to employ a super-charge or other type of charge-intake on the present invention for other applications. For small engines such as the one powering a lawn mower, the cost of the intake-charge might over-weigh the value of the engine, the engine can still be constructed with normal air-intake. 
   SUMMARY OF THE INVENTION 
   It is the primary objective of the present invention to provide a self-cooling internal combustion engine capable of cooling its operation temperature with its own energy. 
   It is the secondary objective of the present invention to provide a self-cooling internal combustion engine capable of operation with less or none additional cooling equipment, thereby decreasing the weight the entire engine. 
   It is another objective of the present invention to provide a self-cooling internal combustion engine which requires a low manufacture cost. 
   It is yet another objective of the present invention to provide a self-cooling internal combustion engine which has a lower exhaust temperature. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is the standard working procedure of one working cycle of the dual six-stroke internal combustion engine. 
       FIG. 2  is a simple illustrative diagram of the first embodiment of the present invention. 
       FIG. 3  is a sectional diagram of the basic unit of the dual six-stroke self-cooling internal combustion engine. 
       FIG. 4  to  FIG. 11  are the sectional diagrams of the dual six-stroke self-cooling internal combustion engine at the beginning of each stroke. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   It should be understood that the drawings are simplified for clarification purpose and common parts of engines such as spark plugs are omitted. 
     FIG. 1  is the standard working procedure of one working cycle, and it should be understood that minor angle adjustments may be applied for engines designed for different applications and specifications. 
     FIG. 3  shows the basic unit of the dual six-stroke internal combustion engine. The primary power cylinder  301 , the secondary power cylinder  303 , and the cooling cylinder  302  are connected to the crankshaft  300 . The primary power cylinder  301  starts air-fuel intake stroke at 0 degree of crankshaft angle. The secondary power cylinder  303  starts air-fuel intake stroke at 360 degree of crankshaft angle. The cooling cylinder  302  starts the first air intake stroke at 90 degree of crankshaft angle, and the second air intake stroke starts at 450 degree of crankshaft angle. Each working cycle consists of twelve strokes, and each stroke repeats every 720 degree of crankshaft rotation. 
   Referring now to  FIG. 2 , the air-fuel mixture is supplied into the primary power cylinder  301  and the secondary power cylinder  303  through the primary intake port  304  and the secondary intake port  306  respectively. The primary exhaust port  311  and the secondary exhaust port  312  are connected to the turbine of the turbo, and the compressor of the turbo is connected to the cooling cylinder intake port  305 , thereby supplying high volume of compressed air into cooling cylinder  302 . 
   The primary coordinating port  307  and the secondary coordinating port  308  provide passage for the compressed cool air from the cooling cylinder  302  into the primary power cylinder  301  and the secondary power cylinder  303  respectively, whereby the coordinating ports in both the primary power cylinder  301  and the secondary power cylinder  303  are designed to forced the compressed cool air to blow onto the inner surface of the engine head in the respective power cylinders. The compress ratio of the cooling cylinder  302  is unlimited, thereby the compressed cool air in the cooling cylinder  302  is completely compressed into the primary power cylinder  301  and the secondary power cylinder  303  at the end of the first compression stroke and the second compression stroke respectively. 
   Referring now to  FIG. 1  and  FIG. 4  to  FIG. 11 , first stroke is the intake stroke of the primary power cylinder  301 , the primary power cylinder  301  is supplied with air-fuel mixture, operating from 0 degree to 180 degree of crankshaft angle. 
   Second stroke is the first intake stroke of the cooling cylinder  302 , the cooling cylinder  302  is supplied with air only from the compressor of the turbo, operating from 90 degree to 270 degree of crankshaft angle. 
   Third stroke is the compression stroke of the primary power cylinder  301 , the air-fuel mixture inside the primary power cylinder  301  is compressed and ignited at designed crankshaft angle, operating from 180 degree to 360 degree of crankshaft angle. 
   Fourth stroke is the first compression stroke of the cooling cylinder  302 , the cool air inside the cooling cylinder  302  is compressed from 270 degree to 450 degree of crankshaft angle, whereby the primary coordinating port  307  is open from approximately 420 degree to 450 degree of crankshaft angle, allowing passage of the compressed cool air into the primary power cylinder  301 ; the compressed cool air is blown onto the inner surface of the engine head, creating a cool air barrier to absorb the heat from the engine head and the expanding working medium. 
   Fifth stroke is the expansion stroke of the primary power cylinder  301 , operating from 360 degree to 540 degree of crankshaft angle; after the combustion process of the air-fuel mixture inside the primary power cylinder  301 , the compressed cool air absorbs the heat from the engine head and mixes with the working medium, thereby instantly lowering the temperature of the working medium inside the primary power cylinder  301 . 
   Sixth stroke is the intake stroke of the secondary power cylinder  303 , the secondary power cylinder  303  is supplied with air-fuel mixture, operating from 360 degree to 540 degree of crankshaft angle. 
   Seventh stroke is the second intake stroke of the cooling cylinder  302 , the cooling cylinder  302  is supplied with air only from the compressor of the turbo, operating from 450 degree to 630 degree of crankshaft angle. 
   Eighth stroke is the exhaust stroke of the primary power cylinder  301 , the working medium is compressed out through the primary exhaust port  311 , operating from 540 degree to 720 degree of crankshaft angle. 
   Ninth stroke is the compression stroke of the secondary power cylinder  303 , the air-fuel mixture inside the secondary power cylinder  303  is compressed and ignited at designed crankshaft angle, operating from 540 degree to 720 degree of crankshaft angle. 
   Tenth stroke is the second compression stroke of the cooling cylinder  302 , the cool air inside the cooling cylinder  302  is compressed from 630 degree to 810 degree of crankshaft angle, whereby the secondary coordinating port  308  is open from approximately 780 degree to 810 degree of crankshaft angle, allowing passage of the compressed cool air into the secondary power cylinder  303 ; the compressed cool air is blown onto the inner surface of the engine head, creating a cool air barrier to absorb the heat from the engine head and the expanding working medium. 
   Eleventh stroke is the expansion stroke of the secondary power cylinder  303 , operating from 720 degree to 900 degree of crankshaft angle; after the combustion process of the air-fuel mixture inside the secondary power cylinder  303 , the compressed cool air absorbs the heat from the engine head and mixes with the working medium, thereby instantly lowering the temperature of the working medium inside the secondary power cylinder  303 . 
   Twelfth stroke is the exhaust stroke of the secondary power cylinder  303 , the working medium is compressed out through the secondary exhaust port  312 , operating from 900 degree to 1080 degree of crankshaft angle. 
   It is also possible to employ a super-charge or other type of charge-intake on the present invention for other applications. For small engines such as the one powering a lawn mower, the cost of the intake-charge might over-weigh the value of the engine, the 8-stroke cycle rotary engine can still be constructed with normal air-intake. 
   The working cycle of said primary power cylinder  301  always leads the working cycle of said secondary power cylinder  303  by 360 degree of crankshaft rotation, the standard trailing angle between the working cycles of said cooling cylinder  302  and said primary power cylinder  301  is 90 degree of crankshaft rotation, however, the trailing angle can be adjusted from 75 degree to 95 degree of crankshaft rotation for embodiments of the present invention with different applications or different fuel types. 
   The standard valve opening time for the said coordinating ports is 30 degree of crankshaft rotation, however, depending on the fuel types and the engine load conditions, the valve opening time can be adjusted from 25 degree to 45 degree of crankshaft rotation. 
   The present invention can be applied in diesel type, propane type, and gasoline type of engines with proper fuel supplying means, and it should be understood that various modifications can be made without leaving the spirit and scoop of the present invention.