WO2014062427A1

WO2014062427A1 - Internal combustion engine with oscillating flow valve

Info

Publication number: WO2014062427A1
Application number: PCT/US2013/063981
Authority: WO
Inventors: Richard Lewis DEBIASSE
Original assignee: Delaware Capital Formation, Inc.
Priority date: 2012-10-15
Filing date: 2013-10-09
Publication date: 2014-04-24

Abstract

An internal combustion engine includes a structure that provides a port and a bore intersecting the port. A valve is rotatably received in the bore and includes an opening that is selectively aligned with the port between the open and closed positions. An electrically operable actuator is operatively coupled to the valve. The actuator is configured to move the valve rotationally between the open and closed positions in response to an electrical signal.

Description

INTERNAL COMBUSTION ENGINE WITH

OSCILLATING FLOW VALVE

BACKGROUND

[0001] This disclosure relates to an internal combustion engine valve train, and more particularly, a type of rotary valve for use in the engine.

[0002] A typical internal combustion engine includes intake and exhaust poppet valves for each cylinder head that selectively regulate the flow of charge air and exhaust into and out of the associated cylinder. Typically, the opening and closing of the linearly moving poppet valves is controlled by a camshaft. The camshaft is mechanically coupled to the engine's crankshaft by a chain or belt to synchronize the opening and closing of the valves in relation to the position of the pistons within each cylinder during the engine cycle. The camshaft includes lobes having profiles that determine when the poppet valves open and close.

[0003] Another type of valve train configuration has been proposed that uses a rotary valve rather than a poppet valve to control the flow into and out of the cylinder. The rotary valve includes one or more valve members that are mechanically coupled to the crankshaft for rotation about the valve's axis in a manner similar to that of a conventional camshaft. Openings are provided in the rotary valve, which intersects the cylinder head port. As the rotary valve is rotationally driven by the crankshaft, the openings in the rotary valve selectively align and misalign with the port to communicate fluid to and from the cylinder. Accordingly, the rotary valves have been mechanically synchronized to the rotation of the crankshaft. This type of valve train configuration has also been used to provide variable timing.

SUMMARY

[0004] In one exemplary embodiment, an internal combustion engine includes a structure that provides a port and a bore intersecting the port. A valve is rotatably received in the bore and includes an opening that is selectively aligned with the port between the open and closed positions. An electrically operable actuator is operatively coupled to the valve. The actuator is configured to move the valve rotationally between the open and closed positions in response to an electrical signal.

[0005] In a further embodiment of the above, the structure is a cylinder head that provides a combustion chamber, and comprises a piston disposed in a cylinder. A Fuel and ignition systems is in communication with the combustion chamber.

[0006] In a further embodiment of any of the above, the cylinder head includes intake and exhaust ports. A valve is arranged in each of the intake and exhaust ports to respectively selectively provide charge air to and exhaust from the combustion chamber through the intake and exhaust ports, respectively.

[0007] In a further embodiment of any of the above, the internal combustion engine includes multiple cylinders, each including multiple valves. The valves of the cylinders are independently actuatable with respect to one another.

[0008] In a further embodiment of any of the above, the valve includes first and second valve members nested relative to one another and moveable in opposite rotational directions in response to the electrical signal.

[0009] In a further embodiment of any of the above, the valve includes a return mechanism cooperating with the first and second valve members to automatically return the valve to one of the open and closed positions with respect to the port.

[0010] In a further embodiment of any of the above, the valve members are rotatable less than 360° during an engine cycle.

[0011] In a further embodiment of any of the above, each of the first and second valve members rotate less than 90° to move between the open and closed positions.

[0012] In a further embodiment of any of the above, the opening includes a raised lip about a perimeter of the opening.

[0013] In a further embodiment of any of the above, the raised lip is provided by a sealing material.

[0014] In a further embodiment of any of the above, the first and second valve members are normally closed during an engine cycle. [0015] In a further embodiment of any of the above, the valve includes a third valve member that provides a bearing for the first and second valve members. The third valve member is fixed with respect to the structure.

[0016] In a further embodiment of any of the above, the first valve member is tubular and includes openings opposite one another.

[0017] In a further embodiment of any of the above, the internal combustion engine includes a controller that is in communication with the actuator and is configured to provide the electrical signal in response to a timing condition.

[0018] In a further embodiment of any of the above, the actuator is an electrohydraulic actuator and includes a hydraulic valve that is operable to move the valve rotationally between the opened and closed positions in response to the electrical signal.

[0019] In a further embodiment of any of the above, the actuator includes a magnetic coil that is operable to rotationally move the valve between the opened and closed position.

[0020] In another exemplary embodiment, a method of controlling fluid flow in an internal combustion engine includes the steps of oscillating a valve between open and closed positions to selectively fluidly obstruct and unobstruct fluid flow through a port.

[0021] In a further embodiment of any of the above, first and second valve members are nested with respect to one another. The first and second valve members oscillate in opposite rotational directions less than 360° of rotation.

[0022] In a further embodiment of any of the above, the method of controlling fluid flow in an internal combustion engine includes the steps of electrically commanding the valve members between the open and closed positions in response to a timing signal.

[0023] In a further embodiment of any of the above, the method of controlling fluid flow in an internal combustion engine includes the steps of referencing an engine rotational position signal to provide the timing signal to control flow through the port in a cylinder head. [0024] The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The disclosure can be further understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0026] Figure 1A is a highly schematic view of an example internal combustion engine utilizing a rotary valve system in the intake and exhaust ports.

[0027] Figure IB is a view of a combustion chamber and exposed intake and exhaust valves.

[0028] Figure 2A is another schematic view of the engine illustrated in Figure 1A having multiple cylinders and intake and exhaust valves independently actuatable relative to one another.

[0029] Figure 3 is a plan view of an example first valve member of one of the valves.

[0030] Figure 4A is a schematic cross-sectional view of example first and second valve members that are oppositely rotatable with respect to one another in response to an electrical signal.

[0031] Figure 4B is an elevational view of a cylinder head.

[0032] Figure 4C is a side view of the cylinder head shown in Figure 4B, but with actuators oriented in a different position.

[0033] Figure 5 is a cross-sectional view of another example rotary valve.

[0034] Figure 6A-6C are cross-sectional views of an example rotary valve that is nested similar to the embodiment shown in Figure 5.

[0035] Figure 7 is a cross-sectional view of yet another example rotary valve. [0036] Figure 8A is a partial cross-sectional view of an opening of an example rotary valve member in sealing engagement with respect to its bore.

[0037] Figure 8B is another partial cross-sectional view of an opening of another example rotary valve member in sealing engagement with respect to its bore.

DETAILED DESCRIPTION

[0038] An internal combustion engine 10 is schematically illustrated in Figure 1A. The engine 10 may be a two- or four-stroke engine. The engine 10 includes a piston 12 arranged for linear movement within a cylinder 14. The piston 12 is connected to a crankshaft 18 by a connecting rod 16. A cylinder head 20 is secured over the cylinder 14 to provide a combustion chamber 26.

[0039] The cylinder head 20 includes intake and exhaust ports 22, 24. A fuel system 28 provides fuel to the combustion chamber 26 with, for example, a direct injector 30, which provides fuel directly into the combustion chamber 26.

[0040] An ignition system 32 is in communication with the combustion chamber 26. In the example, the engine 10 is a spark-ignition engine with a spark plug 34. However, it should be understood that the engine 10 may be a diesel engine that utilizes a glow plug.

[0041] In the example, intake and exhaust valve assemblies 36, 38 are respectively provided within each intake and exhaust port 22, 24. It should be understood that the valve assemblies may be located in close proximity to the combustion chamber 26 such that the intake and exhaust valve assemblies 36, 38 form part of the combustion chamber 26 when closed, as shown in Figures 1A and 4. Alternatively, the intake and exhaust valve assemblies 36, 38 may be located remotely from the combustion chamber, if desired.

[0042] The intake and exhaust valve assemblies 36, 38 are operatively coupled to intake and exhaust actuators 40, 42, respectively. In the example, the intake and exhaust valve assemblies 36, 38 are not mechanically coupled to the crankshaft 18. The intake and exhaust valve assemblies 36, 38 are independently actuatable with respect to one another and independently from the rotation of the crankshaft 18. Instead, the intake and exhaust valve assemblies 36, 38 selectively open and close to obstruct and unobstruct respective openings 122, 124 (oblong or elliptical in shape) in response to an electrical signal, for example, as shown in Figure IB.

[0043] Returning to Figure 1A, a controller 44 is in communication with the intake and exhaust actuators 40, 42. The controller 44 communicates with the fuel system 28 and the ignition system 32. The controller 44 also may be in communication with a position sensor 43, which is a proximity probe, for example, that produces a rotational position signal from a flywheel and/or balancer to enable the controller to determine desired timing. Thus, the controller 44 can independently control the fuel system 28, the ignition system 32 and the air charge and exhaust flow independent from the rotation of the crankshaft 18, although the systems may be timed based upon the rotational position of the crankshaft 18. Said another way, the air, exhaust, fuel and ignition systems are mechanically decoupled from the crankshaft 18 enabling greater control over the engine's operation.

[0044] In one example, the controller 44 may include an Atkinson mode 46, which provides a more efficient mode of operation as compared to a typical Otto cycle combustion engine. The Atkinson mode 46 maintains the intake valve assembly 36 in an open position during at least an initial portion of a compression stroke of the combustion cycle to improve engine efficiency.

[0045] Referring to Figure 2, a multi-cylinder engine 10 is shown. Although a four-cylinder arrangement is illustrated, it should be understood that the disclosed valve train may be used with a single cylinder engine or an engine having any number of cylinders. First, second, third and fourth cylinder heads 20A-20D are illustrated. Each of the cylinder heads 20A-20D respectively include an intake valve assembly 36A-36D that selectively communicates air charge through its respective intake port 22A-22B. An exhaust valve assembly 38A-38D respectively communicates exhaust flow from each of the cylinder heads 20A-20D through its respective exhaust port 24A-24D.

[0046] Each of the intake valve assemblies 36A-36D are operatively coupled to an intake actuator 40A-40D, which are independently actuatable relative to one another. In a similar manner, the exhaust valve assemblies 38A-38D are operatively coupled to exhaust valve actuators 42A-42D, which are independently actuatable relative to one another. The intake and exhaust actuators 40A-40D, 42A-42D communicate with the controller 44. The controller 44 commands the actuators to open and closed positions independently from one another enabling control of the flow into and out of each cylinder.

[0047] Referring to Figures 3 and 4, an example valve assembly is illustrated. A given valve assembly may include first and second rotatable valve members 48, 50 that are nested relative to one another. The valve members may be provided by cylindrical structure that are rotatable about an axis A. The valve members may be constructed from metal, ceramic, plastic and/or composite materials.

[0048] In the example illustrated in Figure 4, both of the first and second valve members 48, 50 are tubular in shape. In the example of a tubular valve member, each valve member includes first and second sets of openings 52A, 52B and 54A, 54B. The openings 52A, 52B and 54A, 54B are illustrated as misaligned with one another in Figure 4. In this closed position, the flow through the passage 56 is obstructed.

[0049] The first valve member 48 is shown in Figure 3. The opening 52A is provided by an elongated slot having an opening width 70 and an opening length 72. The cylinder head 20 defines a port width 74. The ratio of the port width 74 to the opening length 72 is in the range of 2: 1 or greater, for example.

[0050] Returning to Figure 4A, the first and second valve members 48, 50 rotate in opposite directions relative to one another about the axis A, shown by the arrows. Specifically, the first and second valve members 48, 50 oscillate between the open and closed positions so that neither of the valve members need rotate a complete rotation. That is, the valve members rotate less than 360°, and in one example, less than 180°. In the example shown in Figure 4, each valve member rotates about 45°. As a result, the first and second valve members 48, 50 cooperate to move very quickly between open and closed positions, which better ensures that the valve members are fully open or fully closed when desired during the engine cycle.

[0051] The first and second valve members 48, 50 may move rotationally between the open and closed positions, and numerous positions in between. However, a simplified system may be desired in which the valve members move between only two discrete positions: fully opened and fully closed. In one example arrangement, an arm 60 extends from each of the first and second valve members 48, 50. A return spring 62 is provided between the arms 60 to return the first and second valve members 48, 50 to a normally closed position. An open position is schematically illustrated by the dashed lines. In the open position, the arms 60 would be in closer proximity to one another than in the closed position, which is illustrated in Figure 4.

[0052] An actuator 58 cooperates with the arms 60 to move the valve members 48, 50 between the open and closed positions. This type of arrangement enables a single actuator to open and close both valve members.

[0053] It should be understood that a system may be provided that is the reverse of that shown in Figure 4A. That is, the open position may be the normal position, and the actuator 58 may be configured to close the valve members.

[0054] The actuator 58 is an electrohydraulic actuator in one example. The actuator 58 includes a valve 64 in fluid communication with a pressurized hydraulic source 66. The controller 44 communicates with the valve 64 to selectively open and close the valve 64 in response to an electrical signal 68. In the example depicted in Figure 4, an electrical signal 68 would open the valve 64 to permit hydraulic fluid to act on the arm 60 and rotate the first and second valve members 48, 50 in opposite directions relative to one another such that the first and second sets of openings 52A, 52B, 54A, 54B are aligned with one another and the passage 56.

[0055] Another example actuator 158 is shown in Figures 4B and 4C. The actuator 158 includes a solenoid rotationally driving a pinion 144 via a shaft 142. In one example, the solenoid is "Yankee screwdriver"-type actuator that translates the linear motion of the solenoid to rotate the pinion 144. The pinion 144 is rotatable in opposite rotational directions. The pinion 144 simultaneously rotates first and second gear portions 146a, 146b in opposite directions. A desired gear ratio may be achieved by varying the diameters of the pinion and gears. In the example, the first gear portion 146a is coupled to the first valve member 48, and the second gear portion 146b is coupled to the second valve member 50. A cap 120 is secured over the valve assembly to retain the valve assembly relative to the cylinder head 20.

[0056] In another example shown in Figure 5, a third valve member 76 acts as a bearing to the first and second valve members 148, 150. The third valve member 76 is fixed with respect to the cylinder head 20. Openings 77A, 77B are aligned with the first and second sets of openings 152A, 152B, 154A, 154B, to fluidly communicate fluid through the passage.

[0057] Another view of an example rotary valve is shown in Figures 6A-6C, which is nested when assembled in a manner similar to the rotary valve of Figure 5. The first valve member 148 is arranged between the second valve member 150. The third valve member 76 is the outermost sleeve of the valve and affixed relative to the cylinder head 20. The third valve member 76 has a shorter length than the first valve member 148, and the first valve member 148 has a shorter length than the second valve member 150. The openings 152A, 154A, 77 A are aligned with one another when the valve is opened. The first and second valve members 148, 150 respectively include gear portions 246B, 246A that cooperate with one or more actuators to rotate the valve members.

[0058] Another example actuation system is illustrated in Figure 7. The valve member 78 is exemplary of the first and second valve members and may be provided by a structure supporting a first set of windings 80. The structure may be a composite or plastic, for example. In the example, the first set of windings 80 are embedded within the valve member 78, which may be a laminate structure. However, the windings 80 may be provided on the inner and/or outer surfaces of the valve member 78. A second set of windings 82 is provided with respect to the first set of windings 80 to rotate the valve member 78 about the axis A when energized. The first set of windings 80 may be provided on an end of the valve member 78 remote from the port where the second windings 82 may be more easily packaged about the valve member 78.

[0059] The controller 144 is in communication with an electrical source 84 that selectively energizes the first and second sets of windings 80, 82 to effectuate rotational movement of the composite valve member 78.

[0060] Referring to Figure 8A, the valve member 248 provides a lip 92 about a perimeter 94 of the opening 252A that is raised with respect to the outer cylindrical surface 88. The lip 92 more effectively seals against a sealing surface 90 of the cylinder head 20. In one example, the valve member 248 is ground to provide the lip 92.

[0061] Alternatively, the raised substrate may be provided by a sealing material 96 separately adhered about the perimeter 94 of the opening 352 A to seal against the surface 90, as shown in Figure 8B. In one example, the area 98 surrounding the perimeter 94 may be masked during application of the sealing material to the valve member 348.

[0062] It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention.

[0063] Although the different examples have specific components shown in the illustrations, embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.

[0064] Although example embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that and other reasons, the following claims should be studied to determine their true scope and content.

Claims

CLAIMS What is claimed is:

1. An internal combustion engine comprising:

a structure providing a port and a bore intersecting the port;

a valve rotatably received in the bore and including an opening selectively aligned with the port between open and closed positions; and

an electrically operable actuator operatively coupled to the valve, the actuator configured to move the valve rotationally between the open and closed positions in response to an electrical signal.

2. The internal combustion engine according to claim 1 , wherein the structure is a cylinder head that provides a combustion chamber, and comprising a piston disposed in a cylinder, and fuel and ignition systems in communication with the combustion chamber.

3. The internal combustion engine according to claim 2, wherein the cylinder head includes intake and exhaust ports, with a valve arranged in each of the intake and exhaust ports to respectively selectively provide charge air to and exhaust from the combustion chamber through the intake and exhaust ports, respectively.

4. The internal combustion engine according to claim 2, comprising multiple cylinders, each including multiple valves, the valves of the cylinders independently actuatable with respect to one another.

5. The internal combustion engine according to claim 1, wherein the valve includes first and second valve members nested relative to one another and moveable in opposite rotational directions in response to the electrical signal.

6. The internal combustion engine according to claim 5, wherein the valve includes a return mechanism cooperating with the first and second valve members to automatically return the valve to one of the open and closed positions with respect to the port.

7. The internal combustion engine according to claim 5, wherein the valve members are rotatable less than 360° during an engine cycle.

8. The internal combustion engine according to claim 7, wherein each of the first and second valve members rotate less than 90° to move between the open and closed positions.

9. The internal combustion engine according to claim 5, wherein the opening includes a raised lip about a perimeter of the opening.

10. The internal combustion engine according to claim 9, wherein the raised lip is provided by a sealing material.

11. The internal combustion engine according to claim 5, wherein the first and second valve members are normally closed during an engine cycle.

12. The internal combustion engine according to claim 11, wherein the valve includes a third valve member that provides a bearing for the first and second valve members, the third valve member fixed with respect to the structure.

13. The internal combustion engine according to claim 5, wherein the first valve member is tubular and includes openings opposite one another.

14. The internal combustion engine according to claim 1, comprising a controller in communication with the actuator and configured to provide the electrical signal in response to a timing condition.

15. The internal combustion engine according to claim 14, wherein the actuator is an electrohydraulic actuator including a hydraulic valve operable to move the valve rotationally between the opened and closed positions in response to the electrical signal.

16. The internal combustion engine according to claim 14, wherein the actuator includes a magnetic coil operable to rotationally move the valve between the opened and closed position.

17. A method of controlling fluid flow in an internal combustion engine comprising the steps of:

oscillating a valve between open and closed positions to selectively fluidly obstruct and unobstruct fluid flow through a port.

18. The method according to claim 17, wherein first and second valve members are nested with respect to one another, the first and second valve members oscillating in opposite rotational directions less than 360° of rotation.

19. The method according to claim 18, comprising the step of electrically commanding the valve members between the open and closed positions in response to a timing signal.

20. The method according to claim 19, comprising the step of referencing an engine rotational position signal to provide the timing signal to control flow through the port in a cylinder head.