Internal-combustion engines – Multiple cylinder – Cylinders radiating
Reexamination Certificate
1999-04-26
2001-05-01
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Multiple cylinder
Cylinders radiating
C123S197400, C123S197300
Reexamination Certificate
active
06223704
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an spark-ignition engine of the type flat and with opposite cylinders.
BACKGROUND OF THE INVENTION
One flat knows engines and with opposed cylinders, which are equipped with an reticulated connecting rod assembly placed in a casing in two parts whose mating plane is located in the axis of the crankshaft and perpendicular to the plan which passes by the axis of the cylinders.
With this known design of the engines flat and with opposed cylinders, the pressures of explosion are transmitted, through the crankshaft, directly with the screw fasteners of the two half-casings. So very quickly, the casing becomes deformed and flees.
Moreover, with the known engine mentioned above, the crankshaft is heavier because it must comprise masses of balancing much more important. The engine itself is heavy, bulky, and with much of parts moving.
SUMMARY OF THE INVENTION
The present invention has as an aim to cure the disadvantages mentioned above presented by the engines known flat and opposite cylinders mentioned above, and it proposes for this purpose to produce an spark-ignition engine, flat and with opposed cylinders, which constitutes a more compact unit, more rigid and with a maximum of standard and modular parts. It aims at constructing a lighter, more reliable unit and of a less cost price, comprising less parts moving, and showing of a reduced rate of consumption and of pollution.
The spark-ignition engine according to the invention is of the type including at least two cylinders laid out flat and opposed one to the other, a crankshaft ensuring the drive the shaft of exit of the engine of the energy provided by the explosions in the known as cylinders, and a connecting rod assembly connecting the crankshaft to the mobile pistons in the known as cylinders. It is characterized in that the known as connecting rod assembly is rigid and is assembled directly on a cast solid crankshaft, without sliding shoe.
Indeed, by replacing the conventional connecting rod assembly articulated by a rigid connecting rod assembly, the system balances itself and the inertias are withdrawn instead of being cancelled to no purpose, by ensuring a profit of power of approximately 30%. The masses of balancing of the crankshaft are used only for balancing of the crank pins, and, so they are much lighter than with an articulated connecting rod assembly for which it is necessary to take account of the mass of the rod and the piston.
With a rigid connecting rod assembly according to the present invention, the pistons which are perfectly guided do not touch the cylinders, only the ring seals ensure the contact and the sealing with a very weak surface of friction.
According to an additional characteristic of the invention, the spark-ignition engine includes two identical half-casings whose mating plane passes by the axis of the cylinders, the rigid connecting rod assemblies, the flanged guides of the rigid connecting rod assemblies, the pistons and the cylinder heads of the engine. With this provision, the assembly is facilitated and, once the assembled casing, it occurs only very few efforts on the bolts assembling the two half-casings. The casing thus obtained has same rigidity as a cast solid casing.
According to another characteristic of the invention, the half-casings are positioned one compared to the other by the components of the engine, this positioning being ensured in a plan by sealing rings and bearings of guidance of the crankshaft and, in a perpendicular plan, by the flanged guides of the rigid connecting rod assembly. One thus obtains a perfect positioning of the half-casings one compared to the other, without use of the centerpiece necessary with a conventional casing and which bring often only one defective precision.
According to still another characteristic of the invention, the bottom of each cylinder ends in a truncated cone whose top determines an annular light of exhaust with the end of the piston emerging inside the cylinder. This passage of exhaust entirely free, and with a precise adjustment of the exhaust fumes passage by the length of the small diameter of the piston, constitutes a particularly advantageous solution
This solution is made possible, according to a complementary characteristic of the invention, by the fact that the piston presents contrary to the connecting rod assembly a part of small diameter on which the sealing is held by the interior diameter of a ring placed between the cylinder and the cylinder head of the engine, the end of the piston emerging from the known as ring at each point died low, by then allowing the passage of exhaust fumes by the interior diameter of the known as ring.
The lubrication of the ring and the cooling of the cylinder are ensured by an oil circulation in an annular throat laid out between the ring and a shim external to the ring. The gauged exhaust of the oil of the annular throat regulates the oil pressure of the engine.
So that the exhaust fumes are evacuated easily, the cylinder presents a conical end which ensures their guidance and their concentration.
The conical part of the cylinder allows a dynamic overfeeding of the engine. Indeed, during closing to the exhaust of the cone of pressure determined by the cone at the head of the cylinder and the small diameter of the piston, the speed of exhaust of gases is close from the speed of the sound and, with speed, these gases are crushed in the cone and are very strongly densifient from the top of the cone where the pressure is strongest (about 100 bars) to reach a null pressure at the place of the largeest diameter of the cone, the remainder of the cylinder being with a negative pressure whose absolute value increases while approaching the lights of transfer.
Because of the important depression on the level of the lights of transfer, the induction valves open instantaneously under the effect of the difference in pressure between the atmospheric pressure outside the cylinder and the vacuum inside the cylinder, by starting a complementary filling of air. When the induction valves are closed during the closing of the lights of transfer, gas pressure which was standardized a little inside the cylinder reached 4 bars or more before compression does start. This value of 4 bars is however only indicative, and it varies according to the pressure losses, of the dimensions given to the exhaust ports, of transfer, and admission, and speed of revolutions of the engine.
The point angle of the conical part of the cylinder also has a great influence on the value of the dynamic pressure, the aforementioned increasing when this angle increases up to a value of approximately 60°. Thus, more dynamic pressure will be sought, and more one will decrease the point angle of the conical part of the cylinder, until a limit imposed by the pressure loss on the exhaust which becomes too important and/or by a too great height of the unfavourable cone on a good general design of the head of the cylinder.
The dynamic pressure thus generated is so important that the volumetric filling, carried out by the lower part of the pistons in ascending phase, has little importance and can even be lower than 1 without influencing in a sensitive way the dynamic pressure of overfeeding obtained at the moment of the closing of the lights of transfer, right before the phase of compression. It is thus possible to use stems of connecting rod assembly of diameter higher than the small diameter of the pistons, which finds mainly its application on the small engines and the micro engines.
According to another characteristic of the invention, the pistons can be out of steel, aluminium or another metal, and the part of small diameter of each piston is hollow, is filled by a coolant and is closed by a tight stopper. One obtains thus that the combustion chamber remains hot, with a uniform temperature on the height of the piston. According to another realization, the pistons can be out of aluminium with, on the surface, an insulating ceramic layer of great hardness, which is self-lubricating hot lik
Drucker William A.
Huynh Hai
Wolfe Willis R.
LandOfFree
Spark-ignition engine, flat and with opposite cylinders does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spark-ignition engine, flat and with opposite cylinders, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spark-ignition engine, flat and with opposite cylinders will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2521115