The present invention is in the field of internal combustion (IC) engines, and more particularly high efficiency IC engines, and to intake and exhaust valves therefore.
Conventional poppet valves for IC engines have complex and costly camshafts and rocker arm mechanisms to open and close the intake and/or exhaust valves in timing with the reciprocating movement and position of the piston in the cylinder, and are subject to high heat stresses, leakage, and mechanical failure. Also, significant pressure losses in the exhaust gasses are caused by valve stem and valve guide blockages in the exhaust pipe.
The ability to have rapid and precise control of the opening and closing times for internal combustion engine exhaust and intake valves at different operating conditions can result in a significant improvement in engine efficiency. See, for example, U.S. Pat. No. 5,083,533, issued to Richeson et al., incorporated by reference in its entirety. Several automobile companies have developed complex mechanical systems to change the valve timing.
A high spring force is used to close the conventional poppet valve rapidly, and the combustion gas pressure force against the poppet valve is very high. Therefore, if a conventional electrical solenoid is used to open and close this valve, it would quickly overheat, because high electrical currents would be required at high engine speeds. Additionally, the high amount of energy required to control a conventional electric solenoid to open and close the poppet valve reduces engine efficiency.
The present invention provides a solenoid-operated air inlet or combustion exhaust valve for an internal combustion (IC) engine. The solenoid-operated valve can be selected from a rotary exhaust valve assembly or a sliding plate valve.
The present invention also relates to a solenoid-operated rotary valve and its use as a gas valve assembly in an IC engine. The rotary valve includes a fixed housing having a cylindrical bore, the bore being in fluid communication with a gas inlet port and/or a gas outlet port, and a cylindrical valve body disposed rotatably within the bore of the fixed housing, the valve body having a passage transverse to the axis. The passage is sized in cross section to register with the gas inlet and outlet ports to minimize flow blockage and pressure loss. The valve body is rotated on its axis by an electronically-controlled solenoid between a position where the passage is aligned with the gas inlet port and the gas outlet port, deemed an “open” position, and a position where the passage is out of fluid communication with the gas inlet port and/or gas outlet port, deemed a “closed” position. In the closed position the cylindrical surface of the valve body is positioned across the gas inlet and/or gas outlet port, cutting off gas flow between the two ports.
The invention also relates to a rotary exhaust valve assembly for the combustion gas exhaust piping of an internal combustion engine, the rotary exhaust valve having a fixed housing with a cylindrical bore in fluid communication with a combustion gas inlet port and outlet port, and a cylindrical valve body that rotates within the bore of the fixed housing. The valve body has a gas passage transverse to the axis, and an electric linear solenoid that reciprocates linearly and operates a lever to rotate the valve body between an open position that allows exhaust gases to pass through the rotary valve, and a closed position that blocks combustion gas flow from the engine cylinder.
The valve body is rotated within the housing using a mechanical lever and linkage connected to an electrical solenoid. With sufficient lubrication and the use of low friction bearings for the shaft of the valve body, the force and cycle duty required for rotation by the electrical solenoid can avoid overheat. When the rotary valve is used in an exhaust pipe of an IC engine, the valve body outer wall is exposed to high combustion temperatures, which requires either that the interior of the valve body be cooled, or fabrication of the valve body from a heat resistant material, such as a ceramic matrix composite (CMC) material.
The invention also relates to a method of operating an internal combustion engine, comprising the steps of: a. providing a cylinder of an IC engine, b. providing a rotary exhaust valve including a cylindrical valve body having a transverse passage therethrough, the valve body rotatable between a first rotated position wherein the passage is in fluid communication with an inlet gas port and an outlet gas port, and a closed rotated position wherein the passage is not in fluid communication with the inlet gas port or the outlet gas port, c. providing an electric solenoid that operates between a powered position and an unpowered position, d. applying power for a portion of the engine cycle to the electric solenoid to operate the solenoid to its powered position, to effect rotation of the rotary exhaust valve to one of the first rotated position or the second rotated position, e. removing power for a portion of the engine cycle from the electric solenoid to operate the solenoid to its unpowered position, to effect rotation of the rotary exhaust valve to the other of the first rotated position or the second rotated position, and f. repeating steps d. and e.
The present invention provides a sliding plate valve apparatus for a gas intake or exhaust piping for a cylinder of an internal combustion engine, the sliding plate valve apparatus comprising: a plate having a cover portion, a fixed housing having a gas inlet port and a gas outlet port, and a plate cavity within which the plate can slide in a plane substantially perpendicular to the axes of the gas inlet and gas outlet ports, and an electric solenoid that reciprocates to move the plate within the housing between an open position wherein a portion of the plate does not cover the gas inlet port or the gas outlet port to provide fluid communication therebetween. The port is completely open with no restrictions to the flow. Also, in the closed position, the covering portion of the plate covers the gas inlet port, and/or the outlet port, completely.
The invention also relates to a method of operating an internal combustion engine, comprising the steps of: a. providing a cylinder of an IC engine, b. providing a sliding plate valve assembly described herein, c. providing an electric solenoid that operates between a powered position and an unpowered position, d. applying power for a portion of the engine cycle to the electric solenoid to operate the solenoid to its powered position, to effect movement of the sliding plate of the sliding plate valve assembly to one of an open position wherein a portion of the plate does not cover the gas inlet port or the gas outlet port, or a closed position wherein a portion of the plate covers the gas inlet port or the gas outlet port, e. removing power for a portion of the engine cycle from the electric solenoid to operate the solenoid to its unpowered position, to effect movement of the sliding plate to the other of the open position or the closed position, and f. repeating steps d. and e.
An electrical current is required by the solenoid for moving the plate between the opened position and the closed position, or rotating the rotary valve, typically under the control of a programmed computer. The operation of the sliding plate valve or rotary valve, to open and close, can be controlled to provide high engine efficiency at all engine speeds and operating conditions. Examples of systems for powering and controlling solenoid valves are described in U.S. Pat. Nos. 4,949,215 and 6,164,323, the disclosures of which are incorporated herein by reference. Examples of solenoids can include those described in U.S. Pat. No. 5,494,255, the disclosure of which is incorporated herein by reference.
For engine starting conditions with multiple cylinders, and high compression ratio engines, all of the exhaust valves can be held open until a cylinder fires and then the valves can be closed in firing order sequence until the engine is running. This would greatly reduce the power required to start the engine. An advantage of the rotary valve or the sliding plate valve apparatus is the elimination of the complex, costly, and heavy mechanism required for conventional poppet valves. The large, fully open flow path for the exhaust pipes will also reduce exhaust system pressure losses and increase the engine efficiency.
The engine cylinder 1 includes a cylinder wall 2 and a head 4 that define a cylinder space 6. The rotary valve 10 is mounted to an inlet gas pipe 3 of the cylinder head 4 having a gas inlet passage 20, and to an outlet gas pipe 5 having a gas outlet passage 22.
As shown in
A cylindrical valve body 16 is disposed rotatably within the bore 14 of the fixed housing 12. The valve body 16 has a linear passage 18 passing therethrough, transverse to rotational axis 200. The passage 18 is sized in cross section to register with the inlet port 13 and outlet port 15, to minimize flow blockage and pressure loss of gasses passing through the valve. The valve body 16 is rotated by an electronically-controlled solenoid 42 between an open position shown in
The valve body 16 includes a proximal shaft 50 and a distal shaft 52 extending from respective ends, and is supported for rotation within the bore 14 of the housing 12 along proximal shaft 50 and distal shaft 52 with low friction bearings 54 fitted into end plates 19.
As shown in
The electric solenoid 42 can include a push-type or pull-type linear solenoid, substantially as shown in
Optionally, a separate return spring or other mechanical means of biasing the rotary valve to either the open position or the closed position can be employed, to optimize the power requirements of the solenoid or reduce the transition time for movement of the rotary valve between the open and closed positions.
The present invention also provides a sliding plate valve assembly for a cylinder of an internal combustion (IC) engine. The sliding plate valve can be employed as an air inlet valve or as a combustion air exhaust valve or both.
In
The sliding plate valve assembly 110 has a fixed housing 112, a plate 116, and a solenoid apparatus 140. The fixed housing 112 is attached to the valve inlet gas pipe 103 and the valve outlet gas pipe 105 by any mechanical attachment means, including but not limited to bolts, screws, welding and the like. If the valve inlet gas pipe 103 and the valve outlet gas pipe 105 have respectively a valve inlet flange 121 and a valve outlet flange 123, the fixed housing 112 is mechanically attached to the valve inlet flange 121 and valve outlet flange 123. The fixed housing 112 has a first fixed housing bore 130 and a second fixed housing bore 131 that is aligned with the valve inlet gas passage 120 and the valve outlet gas passage 122 along axis 400. The first fixed housing bore 130 and the second fixed housing bore 131 are typically the same cross dimensional sized circular shape as the valve inlet gas passage 120 and the valve outlet gas passage 122, to minimize flow blockage and pressure loss of gasses passing through the sliding plate valve assembly 110.
The fixed housing 112 has a plate cavity 117 substantially perpendicular to axis 400 of substantially rectangular shape, although the plate cavity 117 can be of any shape complementary to the plate 116. The plate cavity 117 is configured to allow the plate 116 to fit and slide laterally with little friction. The plate 116 is defined by plate faces 119 and plate end edges 115,118 to minimize clearance spacing. The plate cavity 117 in the fixed housing 112 has a cross section slightly larger and of the same shape as the plate front edge 115. While the plate 116 thickness, width and length can be of any dimensions, it is preferred that the plate be thin, narrow and short to reduce weight, and can have void or depression areas on either or both sides of the plate, and thus its inertia, when being moved by the solenoid apparatus 140. The fixed housing 112 can be constructed of multiple parts that are mechanically attached and define the plate cavity 117.
In one embodiment, the plate 116 has a plate bore 114 with an axis that is parallel to axis 400. The plate bore 114 is typically of the same size and shape as the first fixed housing bore 130 and second fixed housing bore 131, as to minimize flow blockage and pressure loss of gasses passing through the sliding plate valve assembly 110 in its “open” position aligned with the other passages.
The plate 116 is attached to a solenoid apparatus 140. The solenoid apparatus 140 is defined by an electronically controlled solenoid 142 and an arm 144. The solenoid arm 144 is mechanically attached via linkage 146 to a rod 148, and the rod 148 is attached to plate 116 at the plate back edge 118. Alternatively, the arm 144 can be connected directly to the plate back edge 118.
To operate the sliding plate valve assembly 110, an electric solenoid 142 slides the plate 116 between a position shown in
The electric solenoid 142 can include a pushing solenoid that exerts an extending force outward along an axis of the pushing solenoid when energized, or a pulling solenoid that exerts a contracting force inward along an axis of the pulling solenoid when energized, or a rotary solenoid (not shown, but well known in the art). Examples of solenoids can include those described in U.S. Pat. No. 5,494,255, the disclosure of which is incorporated herein by reference.
The sliding plate valve assembly 110 can be powered by the electric solenoid 142 to move the plate 116 to the open position from the closed position and to the closed position from the open position. Optionally, a separate return spring or other mechanical means of biasing the sliding plate 116 to either the open position or the closed position can be employed, to optimize the power requirements of the electric solenoid 142 or reduce the transition time for movement of the sliding plate 116 between the open and closed positions.
In another embodiment, shown in
In another similar embodiment, the plate 216 and the cavity 217 of the housing 212 are contoured on both the upper face and the lower face.
The fixed housing 112 may optionally include ball bearing(s) or a grease layer or another means for reducing friction and facilitating movement of the plate 116 within the plate cavity 117. The fixed housing or the plate, or both, can be fabricated from a ceramic matrix composite material or any other suitable material known in the art.
It shall be recognized that the drawings illustrating the invention are not intended to be to scale, or provide any limitation to the claimed invention in the size, shape, mass or design features of the sliding plate valve and its assembly. The sliding plate valve need not be any thicker, wider or longer, or of any particular shape, other than as necessary and suitable to cover the openings without air leakage.
In a method of the invention, the electric solenoid operates an air inlet and/a combustion air exhaust valve of a cylinder in the IC engine. In a two-stroke engine, the exhaust valve is closed during the compression, combustion and power phases of one complete cycle, and is open during the exhaust/air inlet phase. The exhaust valve can be in the open position for from one-third to two-thirds of a typical complete cycle. At typical engine speeds, one cycle is about 24 millisec, and the exhaust valve remains open from between 8-16 millisec. The electric solenoid is configured to move from an “off” or unpowered position, to an “on” or powered position with the arm extended, within 0.1-5 millisec. In one embodiment, during each engine cycle, a computer directs electrical power to the linear solenoid to open the rotary valve (the position shown in
Similarly, in another method of the invention, the sliding plate valve assembly operates as an air inlet and/or a combustion air exhaust valve of a cylinder in the IC engine. In a two-stroke engine, the exhaust valve is closed during the compression, combustion and power phases of one complete cycle, and is open during the exhaust/air inlet phase. The exhaust valve can be in the open position for from one-third to two-thirds of a typical complete cycle. At typical engine speeds, one cycle is about 24 millisec, and the exhaust valve remains open from between 8-16 millisec. The electric solenoid can be configured to move from an “off” or unpowered position, to an “on” or powered position with the arm extended, within 0.1-5 millisec. In one embodiment, during each engine cycle, a computer directs electrical power to the linear solenoid to open the plate valve (the position shown in
This application claims the benefit of U.S. provisional patent application 61/691,842, filed Aug. 22, 2012, and of U.S. provisional patent application 61/691,843, filed Aug. 22, 2012, the disclosures of which are incorporated by reference in their entirety.
Number | Date | Country | |
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61691842 | Aug 2012 | US | |
61691843 | Aug 2012 | US |