Patent Application
20140261347
Traditional internal combustion engine operation relies on an expensive valve train including valves, springs, camshafts, and associated bearings and oiling system components, all of which have a negative effect on the primary and maintenance costs and operating efficiency of an engine. Accordingly, there is a need for engine designs that reduce the losses associated with traditional valve train designs in order to increase engine efficiency.
Non-limiting and non-exhaustive embodiments of the devices, systems, and methods, including the preferred embodiment, are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
Disclosed herein are novel internal combustion engine designs. The traditional valve train is eliminated in favor of a rocking or tilting monovalve, or piston valve, for controlling intake and exhaust flow into and out of the combustion chamber. As a result, the valve train is simplified resulting in reduced primary and maintenance costs along with more efficient engine operation.
Specific details of several embodiments of the technology are described below with reference to
Cylinder 102 includes an intake port 110 that conveys air into the combustion chamber 101 and an exhaust port 112 that conveys exhaust away from the combustion chamber 101. An injector 106 provides fuel by direct injection to the combustion chamber, which is then ignited by compression or other methods such as spark, projected plasma, corona, laser, microwave, catalytic or hot spot ignition to provide initiation and/or acceleration of combustion 114. Injector 106 may be any suitable injector capable of direct injection of fuel. Furthermore, injector 106 may be an injector-igniter, which includes fuel injection functions as well as spark or plasma ignition functions. An example of a suitable injector-igniter is disclosed in co-pending U.S. patent application Ser. No. 13/841,548, filed Mar. 15, 2013, the disclosure of which is incorporated herein by reference in its entirety.
Once combustion 114 is initiated at a suitable combustion chamber condition, and the piston 104 begins to move away from top-dead-center (TDC) a power stroke occurs as shown in
In some embodiments, a forced induction device such as a turbocharger (not shown) is connected to the inlet port 110 in order to provide positive air induction to help control the direction of flow into and out of the combustion chamber 101. As shown in the figures, the exhaust port 112 and intake port 110 are offset from each other with the exhaust port 112 offset towards the piston 104. Accordingly, as piston 104 moves towards BDC the exhaust port 112 is covered while inlet port 110 remains open, thereby further directing the flow of air into the combustion chamber 101.
In another embodiment, the engine 100 can be operated in a 4-stroke mode. For example, the intake stroke occurs as the piston 104 moves toward BDC with the piston valve 120 tilted counter-clockwise to facilitate intake flow. Once the piston 104 reaches BDC, the compression stroke begins as the piston 104 travels back toward TDC with the piston valve 120 closed. Once the piston 104 reaches TDC, combustion is initiated on the power stroke and the piston 104 travels back toward BDC with the piston valve 120 closed. Subsequently, the piston 104 approaches BDC, piston valve 120 is opened and tilted clockwise to facilitate exhaust flow as the piston 104 travels toward BDC and reverses to travel toward TDC during the exhaust gas clearing stroke and valve 120 is tilted counterclockwise to facilitate the air sweep into the combustion chamber with improved volumetric efficiency.
The piston 204 is connected to a piston rod 208 that transfers the reciprocating motion of the piston 204 to a motion conversion mechanism 270 which converts reciprocating motion to rotary motion. Piston rod 208 is connected to a cam roller 242 via a roller arm 240. Roller 242 rides along a sinusoidal cam path 274 formed around the circumference of a cam drum 272. Output shaft 276 is connected to the cam drum 272. Thus, reciprocating motion of the piston 204 is converted into rotary motion of output shaft 276. Other suitable motion conversion mechanisms are described in U.S. Pat. No. 4,834,033, issued May 30, 1989 and co-pending U.S. patent application Ser. No. 13/396,572, filed Feb. 14, 2012, the disclosures of which are incorporated herein by reference in their entireties.
The piston 204 includes a piston valve 220, which is operative to seal against a valve seat 244 formed in the top side 205 of the piston 204 when the piston valve 220 is in the closed position. The piston valve 220 includes a valve head 221 attached to valve stem 234 by a pivot 222. Accordingly, valve head 221 may tilt or pivot between a clockwise exhaust position (
The piston valve 220 is biased to a closed position by a suitable magnet or and/or with compression spring 250 either or both of which may be called the compression spring and which may be in a suitable position such the location proximate to bias annulus or retainer 248 shown in
Piston valve head 221 is pivoted between the exhaust and intake positions via linkage, including a pivot rod 236 which is pivotably connected to the valve head 221 and an actuator arm 238. Actuator arm 238 is in turn pivotably connected to the valve stem 234. Torsion spring 252 is disposed on actuator arm 238 and provides a biasing force S2 which biases actuator arm 238 in a clockwise direction corresponding to the exhaust position of the valve head 221. Tilt actuator 260 is operative to act on actuator arm 238 which in turn pushes pivot rod 236 upward in order to rotate the piston valve head 221 counter-clockwise towards the intake position.
With the piston valve head 221 in the exhaust configuration, as shown in
The valve head 221 can be rotated counter-clockwise to the intake position by actuating tilt actuator 260 which in turn rotates actuator arm 238 counter-clockwise which in turn moves pivot rod 236 upwardly to pivot valve head 221 about pivot 222, as shown in
Some aspects of the technology described herein may take the form of or make use of computer-executable instructions, including routines executed by a programmable computer. Those skilled in the relevant art will appreciate that the technology can be practiced on computer systems other than those described herein. The technology can be embodied in a special-purpose computer or data processor, such as an engine control unit (ECU), engine control module (ECM), fuel system controller, or the like, that is specifically programmed, configured or constructed to perform one or more computer-executable instructions consistent with the technology described herein. Accordingly, the term “computer,” “processor,” or “controller” as generally used herein refers to any data processor and can include ECUs, ECMs, and modules, as well as Internet appliances and hand-held devices (including palm-top computers, wearable computers, cellular or mobile phones, multi-processor systems, processor-based or programmable consumer electronics, network computers, mini computers and the like). Information handled by these computers can be presented at any suitable display medium, including a CRT display, LCD, or dedicated display device or mechanism (e.g., a gauge).
The technology can also be practiced in distributed environments, where tasks or modules are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules or subroutines may be located in local and remote memory storage devices. Aspects of the technology described herein may be stored or distributed on computer-readable media, including magnetic or optically readable or removable computer disks, as well as distributed electronically over networks. Such networks may include, for example and without limitation, Controller Area Networks (CAN), Local Interconnect Networks (LIN), and the like. In particular embodiments, data structures and transmissions of data particular to aspects of the technology are also encompassed within the scope of the technology.
The disclosed technology is described above in the context of particular detailed embodiments. However, the following representative embodiments also fall within the scope of the disclosed technology. In an embodiment, an internal combustion engine comprises a combustion chamber having a surrounding sidewall. A piston is slideably disposed in the surrounding sidewall and includes a top side, a bottom side, and a flow passage extending therebetween. A motion conversion mechanism is operative to convert reciprocating motion of the piston into rotary motion. In some embodiments, the motion conversion mechanism comprises a cam drum and at least one roller connected to the piston rod. A piston rod extends between the piston and motion conversion mechanism. A piston valve is moveable between an open position and a dosed position to control fluid movement through the flow passage. The term fluid, as used herein, encompasses gases, liquids, and other states of matter including, for example and without limitation air, fuel, intake gases, and exhaust gases. The piston valve can include a valve head and a valve stem extending through the piston.
The engine can further comprise an intake port and an exhaust port formed through the surrounding sidewall. In some embodiments, the exhaust port is offset from the intake port toward the piston. In still further embodiments, the engine includes a forced induction device, such as a turbocharger or supercharger, in fluid communication with the intake port. In some embodiments, the valve head is positioned adjacent the top side of the piston and the valve stem extends through the piston rod. In some embodiments, the piston valve can be biased toward the closed position, such as with a retainer disposed on the valve stem and a compression spring disposed between a distal end of the piston rod and the retainer. The engine can further comprise a lift actuator, such as a cam or hydraulic cylinder, connected to the valve stem and operable to move the piston valve between the open and dosed positions.
In some embodiments, the valve head can be pivotably connected to the valve stem and include a linkage connected to the valve head and operative to pivot the valve head between an intake position and an exhaust position. Other embodiments can comprise a tilt actuator connected to the linkage and operable to move the valve head between the intake and exhaust positions. The linkage can comprise a pivot rod connected to the valve head and a lever arm pivotably connected to the valve stem and the pivot rod.
In another embodiment, a flow divider extends along a length of the piston rod and is positioned to direct a fluid flow from the intake port, through the flow passage, and out through the exhaust port. In some embodiments, the intake port and exhaust port are positioned on opposite sides of the flow divider. In other embodiments, the intake port and exhaust port are positioned below the top side of the piston.
Also disclosed herein are methods for operating a two-cycle internal combustion engine having a piston disposed in a surrounding sidewall defining a combustion chamber therebetween. In an embodiment, the method comprises injecting a quantity of fuel into the combustion chamber while the piston is near top dead center; igniting the fuel in the combustion chamber; opening a piston valve including a valve head to expose a flow passage through the piston; pivoting the valve head a first direction to direct an exhaust flow from the combustion chamber through the flow passage and out an exhaust port; pressurizing air through an intake port; covering the exhaust port with the piston; pivoting the valve head a second direction to direct an intake flow from the intake port through the flow passage and into the combustion chamber; and closing the piston valve near bottom dead center.
From the foregoing it will be appreciated that, although specific embodiments of the technology have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the technology. Further, certain aspects of the new technology described in the context of particular embodiments may be combined or eliminated in other embodiments. Moreover, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein. The following examples provide additional embodiments of the present technology.
The present application claims the benefit of U.S. Provisional Patent Application No. 61/801,342, filed Mar. 15, 2013, the disclosure of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61801342 | Mar 2013 | US |
