Title of Invention

"2-CYCLE INTERNAL COMBUSTION ENGINE"

Abstract

[Means of Solution] A 2-cycle internal combustion engine 2, having a mixture of compressed air from an air tank 94 and fuel from a fuel injection device 13 supplied to a combustion chamber 96 through a rotary valve 74, auxiliary devices 12, 14, 76 such as an oil pump, water pump etc. and a shaft of the rotary valve 74 being driven by rotation of a crankshaft 21, wherein the auxiliary devices 12, 14, 76 are attached to the shaft of the rotary valve 74. [Effect] By attaching auxiliary devices to the shaft of the rotary valve, there is no longer any need for a shaft and bearing dedicated to the auxiliary devices, the number of engine components can be reduced, and the engine can be made lightweight.

Full Text

[Detailed Description of the Invention] [ Background of the Invention] The present invention relates to a 2-cycle internal combustion engine. Related Art] The arrangement of auxiliary devices of an engine is known, for example, from (1) Japanese Utility Model Application Laid-open No. Sho. 62-79912, entitled "Engine Oil Pump Drive Apparatus" and (2) Japanese Patent Application Laid-open No. Hei. 2-245422 entitled "Engine Auxiliary Attachment Structure". The above mentioned art (1) discloses an oil pump attached to a transmission case through a resilient body, as is shown in Fig. 1 of that publication, the oil pump 13 being coupled to an outer end of the crankshaft 1. The above mentioned art (2) discloses means for making an engine small in size, and enabling a simple cover construction, as is disclosed in Fig. 2 of that publication, a crankshaft 5, a pump shaft 21 driven by the crankshaft 5, a water pump 17 comprised of this pump 21, and an oil pump 2 connected to the pump shaft 21. [Problems to be Solved by the Invention] In publication (1) above, because an oil pump 13 is arranged on an extension of the crankshaft 1, there is a drawback that the overall width of the engine becomes large. In publication (2) above, for example, compressed air from an air chamber is mixed with fuel from a fuel injection device, and the mixture is supplied to the combustion chamber through a rotary valve. In this case, there is a problem that shafts and bearings must be provided for the rotary bearing as well as for a water pump 17 and an oil pump 26. An object of the present invention is therefore to provide a 2-cycle internal T combustion engine in which the same shaft is used for auxiliary devices such as a water pump, an oil pump, etc., and a rotary valve, without making the overall width of the engine large. [Means of Solving the Problems] In order to achieve the above stated object, claim 1 of the present invention is directed to a 2-cycle internal combustion engine, having a mixture of compressed air from an air tank and fuel from a fuel injection device supplied to a combustion chamber through a rotary valve, auxiliary devices such as an oil pump, water pump etc. and a shaft of said rotary valve being driven by rotation of a crankshaft, and the auxiliary devices being attached to the shaft of the rotary valve. By attaching the auxiliary devices to the shaft of the rotary valve, shafts and bearings dedicated to the auxiliary devices are no longer necessary, the number of components of the engine can be reduced and the engine can be made light weight. Claim 2 is directed to a 2-cycle internal combustion engine, having a mixture of compressed air from an air tank and fuel from a fuel injection device supplied to a combustion chamber through a rotary valve, auxiliary devices such as an oil pump, water pump etc. and a shaft of said rotary valve being driven by rotation of a crankshaft via an idler shaft and a belt or chain, and the auxiliary devices being attached to the idler shaft. By attaching the auxiliary devices to the idler shaft, shafts and bearings dedicated to the auxiliary devices are no longer necessary, the number of components of the engine can be reduced and the engine can be made light weight. Accordingly the present invention relates to a 2-cycle internal combustign engine, having a mixture of compressed air from an air tank and fuel from a fuel injection device supplied to a combustion chamber through a rotary valve, auxiliary devices and a shaft of said rotary valve being driven by rotation of a crankshaft, said auxiliary devices are attached to the shaft of said rotary valve. [Brief Description of the Accompanying Drawings] Fig. 1 is a side elevation of a power unit of a motorcycle according to tht^O present invention. Fig. 2 is a cross sectional drawing along line 2-2 in Fig. 1. Fig. 3 is a cross sectional drawing along line 3-3 in Fig. 1. Fig. 4 is a side elevation of rotational transmission path from the crank shaft shown in Fig. 3 to the rotary valve. Fig. 5 is a vertical cross sectional drawing through the cylinder shaft according to the present invention. Fig. 6 is a cross sectional drawing along line 6-6 in Fig 1. Fig. 7 is a side elevation showing a separate embodiment of a 2-cycle internal combustion engine according to the present invention. [ Embodiments of the vention] Embodiments of the present invention will now be described based on the attached drawings. The drawings use reference numerals. Fig. 1 is a side elevation of a power unit of a motorcycle according to the present invention, and the power unit 1 comprises an engine 2, and an continuously variable transmission 3 connected to an output side of the engine 2. The drawing shows the state with the case cover of the transmission 3 removed. In this drawing, 11 is a spark plug, 12 is a water pump, 13 is a fuel injection valve. 14 is an oil pump, 15 is a throttle, 16 is a starter motor, 17 is a pinion capable of moving in the direction of a shaft, 18 is a ring gear that can engage with the pinion 17, 21 is a crank shaft attached to the ring gear 18. 22 and 23 are sections for attaching to a vehicle frame, 31 is a transmission case formed integrally with an engine crank case, 32 is a driven shaft transmitting rotation from the crankshaft 21 by a V belt (not shown), 33 is a clutch for enabling and disabling rotation from the crankshaft 21 to the driven shaft 32. - *^- Fig. 2 is a cross sectional drawing along line 2-2 in Fig. 1, and the engine 2 comprises left and right crank cases 25 and 26 supporting a crankshaft 21 via bearings 24, a drive pulley 27 provided on one end of the crankshaft 21, a kick starter 28 provided facing the other way to the direction of the axis of this drive pulley 27, an AC generator 41 provided on the other end of the crankshaft 21, a slit disc 42 attached to the outside of the AC generator 41, and a crank angle sensor 43 for detecting the crank angle etc. from the slit of the slit disc 42. The engine 2 also comprises a connecting rod 46 connected to the crankshaft 21 through a crank pin 45, a piston 48 connected to the connecting rod 46 through a piston pin 47, a cylinder block 51 having a cylinder 49 in which the piston 48 reciprocates, and a cylinder head 52 attached to the end of the cylinder block 51. In this drawing, 21a and 21b are counterweights, 21c is a gear for driving an oil pump, 53 is an oil pump shaft attached to a worm gear, 54 is movable pulley half comprising a ring gear 18 and a drive pulley 27, 55 is plate fixed to the crankshaft 21, 56 is a weight provided between the movable pulley half 54 and the plate 55 so as to move in a radial direction due to centrifugal force, 57 is a V belt, 58 is an oil seal, 61 and 62 are needle bearings, 63 and 64 are scavenging ports, 65 is a water jacket, and 66 is a water temperature sensor. Fig. 3 is a cross sectional drawing along line 3-3 in Fig. 1, and shows that a drive gear 68 is attached to the crankshaft 21 and is engaged with an idler gear 71 and a drive pulley 72 is attached to the shaft end of the idler gear 71. On the other hand, a rotary valve 74 is rotatively supported in the cylinder block 51 via the bearings 73, and a water pump 12 and a slave pulley 75 are attached to one end of the rotary valve 74. A fuel pump 76 is attached to the other end of the rotary valve 74, and a toothed belt 77 is stretched across the drive pulley 72 and the slave pulley 75. 78 is a needle bearing, 83 is an oil seal and 84 is seal member. With the above described construction, the rotary valve 74 is reversed compared to the direction of rotation of the crankshaft 21. In this way, by attaching a water pump 12 and fuel pump 76 to the shaft of the rotary valve as auxiliary devices, shafts and bearings dedicated to the water pump 12 and fuel pump 76 are not required, the number of components of the engine 2 can be reduced and the engine can be made light weight. Further, the engine 2 can be made small in size, and space within the engine 2 can be efficiently utilized. Fig. 4 is a side elevation of rotational force transmitting path from the crank shaft shown in Fig. 3 to the rotary valve, and shows an idler pulley 85 pushed into the toothed belt 77 stretched across the drive pulley 72 and the slave pulley 75. In this drawing, 86 is an attachment member of the idler pulley 85. Flapping of the toothed belt 77 at high speed is prevented by this idler pulley 85. Fig. 5 is a vertical cross sectional drawing through the cylinder shaft according to the present invention, and shows reed valves 88 and 81 provided in the crank cases 25 and 26 (25 is not shown) so as to face an entrance of the crank chamber 87, with an intake manifold 92 provided upstream of the reed valves 88 and 91, and a throttle 15 being provided upstream of the intake manifold 92. 93 is a scavenging port. Fig. 5 also shows a chamber 94 provided between the cylinder block 51 and the cylinder head 52 for amassing compressed air. A mixture of the compressed air from this chamber 94 and fuel from a fuel injection valve 13 is supplied from a fan shaped rich mixture injection port 95 to a combustion chamber 96, through the rotary valve 74, and an exhaust valve 98 is provided at an entrance to the exhaust port 97 for discharging combusted gas. Fig. 6 is a cross sectional drawing along line 6-6 in Fig 1, and shows that the rich mixture injection port 95 has a fan shape in a direction at right angles to the cylinder axis. In this way, because the rich mixture injection port 95 has a fan shape in a direction at right angles to the cylinder axis, and substantially in a direction of the cylinder shown in detail in Fig. 5, fuel that has been vigorously injected from the rotary valve 74 into the rich mixture injection port 95 spreads out almost conically, which means that it flows quite smoothly along the fan shaped surface of the rich mixture injection port 95 sticking to a wall surface. It is therefore possible to promote atomization of the fuel, and more complete combustion can be carried out. Accordingly,it i s possi ble to improve fuel economy and exhaust purification efficiency. In Fig. 6, 99, 99 are compressed air paths, and compressed air is circulated into the chamber 94 from the cylinder 49 via the rotary valve 74. The functions of the rotary valve 74 are (a) to open and close a compressed air path from inside the chamber 49 to the chamber 94, and (b) to open and close a rich mixture path from the chamber 94 and the fuel injection valve 13 to the rich mixture injection port 95. The above described function is carried out so that air compressed by a compression stroke flows from the cylinder 49 to the chamber 94 via the compressed air paths 99 (refer to Fig. 6). The timing for opening the rotary valve 74 at this time is the same point in time as the compression stroke is started with the piston 48 rising from bottom dead center, and the timing for closing the valve is after the fuel injection from the fuel injection valve 13 described in (b) above has been stopped. As the function (b), air that has been accumulated in the chamber 94 and fuel from the fuel injection valve 13 are injected together from the rich mixture injection port 95, and the timing for opening the rotary valve 74 at this time is the point at which the piston 48 rises from bottom dead center and after the upper end of the piston 48 has closed the scavenging port 93, and the timing for closing the valve is the point in time after a fixed amount of fuel has been injected. Fig. 7 is a side elevation showing a separate embodiment of a 2-cycle internal combustion engine according to the present invention, and constructional elements that are the same as in the embodiment described in Fig. 1 to Fig. 6have the same reference numerals attached, and repeat description will be omitted. An engine 101 has a crankshaft 21 rotatively attached to a crankcase 102 that also functions as a transmission case, a drive pulley 103 is attached to this crankshaft 21, a cylinder block 104 is attached to the crankcase 102, a rotary valve 74 is rotatively attached to the cylinder block 104, a slave pulley is attached to the rotary valve 74, a cylinder head 105 is attached to the cylinder block 104, an idler shaft 106 is rotatively attached to the cylinder head 105, auxiliary devices (not shown) such as a water pump, an oil pump, a fuel pump etc. and an idler pulley 107 are attached to the idler shaft 106, and a toothed belt 108, being toothed on both sides, is stretched across the drive pulley 103, slave pulley 75 and idler pulley 107. By using the above described toothed belt 108, the rotary valve 74 can be reversed compared to the crank shaft 21. In this way, by attaching the auxiliary devices to the idler shaft 106, bearings and shafts dedicated to the auxiliary devices are no longer require, the number of components of the engine 101 can be reduced, and the engine can be made small in size. [Effects of the Invention] Due to the above construction, the present invention can achieve the following effects. Because the auxiliary devices are attached to the rotary valve, the 2-cycle internal combustion engine of claim 1 can do away with the need for bearings and shafts dedicated to the auxiliary devices, reduce the number of components of an engine and make the engine small in size. Because the auxiliary devices are attached to the idler shaft, the 2-cycle internal combustion engine of claim 2 can do away with the need for bearings and shafts dedicated to the auxiliary devices, reduce the number of components of an engine and make the engine small in size. [Description of the Numerals] 2 2-cycle internal combustion engine (engine) 12, 14, 76 auxiliary devices (water pump, oil pump, fuel pump) 13 fuel injection device (fuel injection valve) 21 crankshaft 74 rotary valve 94 air chamber (chamber) 96 combustion chamber 106 idler shaft 108 belt (toothed belt) WE CLAIM: 1. A 2-cycle internal combustion engine [2], having a mixture of compressed air from an air tank and fuel from a fuel injection device[13] supplied to a combustion chamber[96] through a rotary valve[74], auxiliary devices [12, 14, 76]and a shaft of said rotary valve[74] being driven by rotation of a crankshaft[21], characterized in that said auxiliary devices are attached to the shaft of said rotary valve|74|. 2. A 2-cycle internal combustion engine, as claimed in claim 1, wherein the auxiliary devices are an oil pump, or water pump. 3. A 2-cycle internal combustion engine substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

850-del-1998-abstract.pdf

850-del-1998-claims.pdf

850-del-1998-correspondence-others.pdf

850-del-1998-correspondence-po.pdf

850-del-1998-description (complete).pdf

850-del-1998-drawings.pdf

850-del-1998-form-1.pdf

850-del-1998-form-13.pdf

850-del-1998-form-19.pdf

850-del-1998-form-2.pdf

850-del-1998-form-3.pdf

850-del-1998-form-4.pdf

850-del-1998-form-6.pdf

850-del-1998-gpa.pdf

850-del-1998-petition-137.pdf

850-del-1998-petition-138.pdf

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