A TWO STROKE INTERNAL COMBUSTION ENGINE

Abstract: The engine according to the invention comprises a cylinder body (101) including at least one power piston/cylinder combina­ tion (104, 103) and at least one auxiliary piston/cylinder combina­ tion (108, 102) with the said combinations disposed in coaxial relationship, a separating wall disposed between adjacent pis­ ton/cylinder combinations, a connection rod (117) coaxially interconnecting the pistons (104, 108) for synchronous move­ ment thereof between top- and bottom-dead-centre positions of the pistons and sealingly passing through said separating wall or walls, a connecting rod (106) and crank-shaft for converting reciprocal motion of the said combination into a rotational output, an exhaust port (109) for discharging exhaust gases from the cylinder (103) when the power piston (104) is in the region of bottom-dead-centre, an inlet port (111) including a one-way a valve (112) in communication with at least that auxiliary cylinder (102) adjacent the power cylinder, means for controlling opera­ tion of the said one-way valve (112) in accordance with the engine firing cycle, a gas transport passage (113) interconnecting a power cylinder (103) and an adjacent auxiliary cylinder (102), and a valve (114) for controlling transportation of gas through the passage (113), a gas pump chamber (102′) disposed on at least that side of an auxiliary piston (108) remote from an adjacent power piston (104) for compressing gaseous media, and means (110, 110′) for igniting a fuel/gas mixture in each power cylinder or injecting fuel into each power cylinder.

Description: This invention relates to a reciprocating internal combustion engine including a separate gas chamber. DE-C-504 514 describes and claims a two-stroke internal combustion engine including an operating piston/cylinder combination (b/a), a compressor piston/cylinder combination (d/c) with pistons (b/d) connected by a common hollow connecting rod (e) having control slots (f/fi) for scavenging air. A rotary slide valve (g) serves, simultaneously, to control scavenging air and the paths for air-gas mixture between the compressor cylinder (c) and an operating cylinder (a). The engine also includes a residual gas chamber (h) which communicates with a further rotary slide valve (l) via passages (i/ii). A connecting duct (m) constituting a gas transport passage connects the compressor cylinder (c) above the piston (d) with the operating cylinder (a) above the piston (b). According to the present invention, a two-stroke internal combustion engine comprising an engine block (10) having an upper cylindrical gas chamber (102) and a lower cylindrical gas chamber (103), said lower chamber serving as a combustion chamber; a piston assembly comprising a lower piston (104) located in said lower gas chamber, an upper piston (108) located in said upper gas chamber and dividing said upper gas chamber into two portions including a top upper chamber portion and a bottom upper chamber portion, one of said two portions defining a compression chamber for a fuel/air mixture, and a shaft (117) connecting said upper and lower pistons for moving both upper and lower pistons in phase with one another; sealing means (118) permitting reciprocating movement of said connecting shaft within said upper and lower chambers and providing a seal between said upper and lower chambers; cooling means (116) jacketing said sealing means for cooling said sealing means; a fuel/air source providing a fuel/air mixture; upper chamber intake means (111) for allowing the fuel/air mixture from said fuel/air source to be introduced into said compression chamber; an inter-chamber passageway (113) for permitting flow of the fuel/air mixture from said compression chamber to said lower chamber, said interchamber passageway located near the top of said lower chamber; lower chamber intake valve means (114) for controlling flow of the fuel/air mixture from said interchamber passageway to said lower chamber; lower chamber exit means (109) for permitting the contents of said lower gas chamber to be discharged from said lower gas chamber, said lower chamber exit means located near the bottom of said lower chamber exit means located near the bottom of said lower chamber and controlled by travel of said lower piston; and ignition means (110) for igniting the gaseous contents of said lower chamber, said ignition means automatically periodically being energized and unenergized in co-ordination with the automatic operation of said lower chamber intake valves means; characterised in that, the compression chambers is defined by said bottom portion of said upper gas chamber (102); the inter chamber passageway (113) is located in a part of the engine block separating said upper gas chamber (102) and said lower gas chamber (103) for permitting flow of the fuel/air mixture from said bottom portion of said upper chamber directly to said lower chamber; the lower chamber intake valve means (114) is controlled by a crankshaft cam, the engine comprises one-way upper chamber intake means (112) for preventing gas from exiting from said bottom portion of said upper gas chamber through said upper chamber intake; wherein the fuel/air mixture from the fuel/air mixture source passes in sequence through said one-way upper intake means, said lower portion of said upper chamber, said inter-chamber passageway in said engine block, and said crankshaft-cam controlled lower chamber intake valve means prior to entry into said lower chamber. During operation of the engine of DE-C-504 514 a first compression phase is obtained during downward movement of the upper piston (d) and high pressure combustion gases are forced into the combustion chamber (a) from a fixed point via the slots (f1) formed in the wall of the hollow connecting rod (e). The relative axial positions of slots (f) and (f1) are fixed and cannot be adjusted unless the engine is stripped down and a new connecting rod used having a different formation of slots (f/f1). Such non-adjustability necessitates the inclusion of the chamber (h) for accepting any residual combustible mixture remaining in the compression chamber. Completion of the cycle of DE-C-504 514 is accomplished by secondary compression during upward movement of piston (b) and finally ignition which occurs at or just prior to top-dead-centre. In contrast, during operation of the engine according to the present invention, initial compression is achieved during downward movement of the piston 108 and the high pressure combustion mixture is forced into chamber 103 via the passage 113 under the control of valve 114. Secondary compression is effected during upward movement of piston 104 and ignition takes place at or just prior to top-dead-centre. An engine in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a sectional diagram of a back and forth motion type of internal combustion engine with a separate gas chamber; Fig. 1-1 is a sectional diagram taken at right angles to the sectional diagram of Figure 1; Fig. 2-1 is the diagram of the intake phase of the engine; Fig. 2-2 is the diagram of the pressure and ignition phase of the engine; Fig. 2-3 is the diagram of the expansion phase of the engine; Fig. 2-4 is the diagram of the exhaust phase of the engine; Fig. 3 is the diagram of an example of a gas pump using the upper piston; and Fig. 4 is the diagram of an example of a drive turbine pressurizing equipment using the upper piston drive pump. Referring to Figures 1 and 1-1, a cylinder block 101 has an upper cylinder 102 and a lower cylinder 103. The lower cylinder 103 has a lower piston 104 attached to a crank shaft 107 by a pin 105. An upper piston 108 divides the upper cylinder 102 into upper and lower gas chambers 102' and 102. A connecting rod 117, connects the two pistons 104 and 108 so that they are movable in synchronism, reaching top-dead centre and bottom-dead centre simultaneously. An exhaust opening 109 is located at the lower-most stop point of the lower cylinder 103. An ignition plug 110 is located in the vicinity of the top of the lower cylinder 103. When we use jet oil inlet 110', only fresh airs can come into the pressure input gas chamber. An intake opening 111 is located in the vicinity of the lower most point of the upper gas chamber 102 and it is equipped with a single way valve 112. Referring to Figure 1-1, one end of a gas transport passage 113 opens into the vicinity of the lower most region of the upper gas chamber 102. The other end of the passage 113 opens into the uppermost region of the lower gas chamber 103, thereby interconnecting the chambers 102 and 103. An intake valve 114 is used for controlling the opening and closing of the gas transport passage 113. The valve 114 is controlled by a synchronisation mechanism M, driven by the engine crankshaft C. When the lower piston 104 returns from the region of bottom dead centre to top dead centre, the valve 114 opened to allow the combustion gas to enter the lower gas chamber 103 used for the combustion chamber. The upper gas chamber 102' is formed above the upper piston 108 and an upper member 120 of the engine casing. The upper member 120 includes one or more gas openings 119 which may be equipped with additional inlet and outlet valves not shown to form a pump for water, oil or gas, or for the movement of a pressurizing turbine. An ignition coil may be used to ignite the combustible gases when the lower piston 104 has reached top dead centre. When the engine is running, combustible gases enter the upper gas chamber 102 through the intake opening 111 and the single way intake valve 112 during upward movement of the upper piston 108. When the upper piston 108 pumps downwardly and the combustible gases are compressed and agitated in the vicinity of bottom dead-centre, the intake valve 114 is opened, the combustible gases enter the lower gas chamber 103 through the combustion gas transport passage 113 and forces exhaust gases through the exhaust opening to atmosphere. When the lower piston 104 returns to top dead-centre, the ignition coil causes ignition plug 110 to operate and ignite the fresh combustible gases. At this stage, the upper piston 108 has completed its inlet stroke and is now ready for the compression phase of the cycle. A cooling opening 116 is used for introducing coolant to cool an oil seal 118 surrounding the crankshaft 117, the outer oil tank, the cooling fan or the liquid pump, the cooling liquid tank and the start motor etc. For its movement process, please refer to Fig. 2-1, 2-2, 2-3 & 2-4. An internal combustion engine in accordance with the present invention possesses the following advantages. 1. The intake opening is located diagonally with the exhaust opening. Therefore, the elimination of the waste gas is easier and its combustion gas has less than the traditional two travel engine intake and exhaust openings. Thus the combustion efficiency and the engine power are increased. 2. The curved shaft and the piston lubrication system can use the semi-closed dipping type, so that the combustion oil system is separated from the lubrication system. Therefore, there is no need to add the mixture of the lubrication oil and the motor oil to gasoline due to the transport of the combustion gas through the curved shaft tank as the traditional double-acting engine. Thus the smog pollution after the combustion can be avoided. 3. It needs less parts and has the simple structure. 4. A pump function is formed by the upper gas chamber 102' and the upper piston 108. Therefore, it can be used as the fluid pump, when we use the single way intake valve and the exhaust valve. In the example of Fig. 3, the engine uses a compression air pump and avoids the use of a transmission system and an independent gas pump cylinder which is needed in a traditional engine. Thus costs are reduced and efficiency increased. Referring to Fig. 3, 301 is an intake valve, 302 is an exhaust valve equipped at the upper side of the upper gas chamber or on the upper cover and 303 is an air filter connected to the front of the intake valve 301. A pressure reservoir 304 is connected with the exhaust valve 302, 305 is a pressure reducing valve connected with the pressure reservoir 304 and 306 is pressure manometer. The embodiment of Figure 3 forms an air compressor system for driving the air-driven apparatus. The compressor of Figure 3 may be driven by a turbine pressrizer as illustrated in Fig. 4. In Fig. 4, 401 is an air drive turbine having an air pump outlet 402 coupled with an intake opening 403. A gas pump inlet 404 is connected with a carburetor, not shown. The upper section of the upper gas chamber and each side of the upper piston 406 form a gas pump chamber 405. A pump inlet 407 is fitted with the single way valve 408, the pump outlet is connected with the drive inlet 409 of the turbine equipment and exhausts through outlet 410, so that the intake pressure increases during the running of the engine.

Claims: A two-stroke internal combustion engine comprising an engine block (10) having an upper cylindrical gas chamber (102) and a lower cylindrical gas chamber (103), said lower chamber serving as a combustion chamber; a piston assembly comprising a lower piston (104) located in said lower gas chamber, an upper piston (108) located in said upper gas chamber and dividing said upper gas chamber into two portions including a top upper chamber portion and a bottom upper chamber portion, one of said two portions defining a compression chamber for a fuel/air mixture, and a shaft (117) connecting said upper and lower pistons for moving both upper and lower pistons in phase with one another; sealing means (118) permitting reciprocating movement of said connecting shaft within said upper and lower chambers and providing a seal between said upper and lower chambers; cooling means (116) jacketing said sealing means for cooling said sealing means; a fuel/air source providing a fuel/air mixture; upper chamber intake means (111) for allowing the fuel/air mixture from said fuel/air source to be introduced into said compression chamber; an inter-chamber passageway (113) for permitting flow of the fuel/air mixture from said compression chamber to said lower chamber, said interchamber passageway located near the top of said lower chamber; lower chamber intake valve means (114) for controlling flow of the fuel/air mixture from said interchamber passageway to said lower chamber; lower chamber exit means (109) for permitting the contents of said lower gas chamber to be discharged from said lower gas chamber, said lower chamber exit means located near the bottom of said lower chamber exit means located near the bottom of said lower chamber and controlled by travel of said lower piston; and ignition means (110) for igniting the gaseous contents of said lower chamber, said ignition means automatically periodically being energized and unenergized in co-ordination with the automatic operation of said lower chamber intake valves means; characterised in that, the compression chambers is defined by said bottom portion of said upper gas chamber (102); the inter chamber passageway (113) is located in a part of the engine block separating said upper gas chamber (102) and said lower gas chamber (103) for permitting flow of the fuel/air mixture from said bottom portion of said upper chamber directly to said lower chamber; the lower chamber intake valve means (114) is controlled by a crankshaft cam; the engine comprises one-way upper chamber intake means (112) for preventing gas from exiting from said bottom portion of said upper gas chamber through said upper chamber intake; wherein the fuel/air mixture from the fuel/air mixture source passes in sequence through said one-way upper intake means, said lower portion of said upper chamber, said inter-chamber passageway in said engine block, and said crankshaft-cam controlled lower chamber intake valve means prior to entry into said lower chamber. A two-stroke engine according to claim 1 in which the portion (405) of the pre-compression cylinder on the side of the piston opposite to that functioning for pre-compression is provided with valves (301,302) so as to form an integral engine/pump unit. A two-stroke engine according to claim 1 in which the portion (405) of the pre-compression cylinder on the side of the piston opposite to that functioning for pre-compression drives a turbo supercharger (401).

Inventors: YANG, TAI-HER
Applicants: YANG, TAI-HER
Application year: 1986
Main classification: F02B33
IPC codes: F02B63, F02B33, F02B75