variable displacement engine

Abstract

The combustion engine includes a main combustion cylinder configured to have a piston movable therein, a main valve configured to move within the main combustion cylinder, an upper non-combustion chamber operatively adjacent to the main combustion cylinder, an upper intake valve configured to move within the upper non-combustion chamber and communicate with an intake manifold, and an upper exhaust valve configured to move within the upper non-combustion chamber and communicate with an exhaust manifold.

Description

[Background technology]

[0001] The present invention relates generally to varying the displacement of a combustion engine, and more particularly to an apparatus and method for varying engine displacement by varying the timing of intake and / or exhaust gases.

[0002] Modern combustion engines must meet government standards for low emissions and high fuel economy, provide sufficient power for drivability, and ensure high reliability. Many modern gas combustion engines utilize the Otto cycle to achieve high power density.

[0003] To meet government emissions and fuel economy standards, car and truck manufacturers are using small-displacement engines. Small-displacement engines have low power output, which makes the vehicle slow and sluggish to accelerate, resulting in poor driving performance. To get around this low power output, vehicle manufacturers use turbochargers or twin-turbochargers and transmissions with gear ratios that produce high engine speeds.

[0004] However, engines that operate at high RPMs wear out faster than engines that operate at lower RPMs. Small-displacement engines have smaller bores and strokes. Small bores and strokes require smaller engine components, such as the crankshaft, camshafts, bearings, pistons, connecting rods, and engine block. Smaller crankshafts, pistons, and connecting rods have a lower power capacity and, in the long term, will have a shorter lifespan than engines with larger components.

[0005] Thus, there is a need for an improved system and method for varying engine displacement in response to engine load variations. Summary of the Invention

[0006] In one aspect of the disclosure, a combustion engine includes a main combustion cylinder configured to have a piston moveable therein, a main valve configured to move within the main combustion cylinder, an upper non-combustion chamber operatively adjacent to the main combustion cylinder, an upper intake valve configured to move within the upper non-combustion chamber and communicate with an intake manifold, and an upper exhaust valve configured to move within the upper non-combustion chamber and communicate with an exhaust manifold.

[0007] In another aspect of the present disclosure, a combustion engine includes a main combustion cylinder, a main valve within the main combustion cylinder, an upper non-combustion chamber in gaseous communication with the main combustion cylinder, an upper intake valve within the upper non-combustion chamber, and an upper exhaust valve within the upper non-combustion chamber, wherein the main valve, the upper intake valve, and the upper exhaust valve are configured to move independently of one another in a timed manner.

[0008] In a further aspect of the present disclosure, a combustion engine includes a main combustion cylinder, a main valve within the main combustion cylinder, an upper non-combustion chamber configured to operate in an intake mode, a compression mode, and an exhaust mode with the main combustion cylinder, an upper intake valve within the upper non-combustion chamber, and an upper exhaust valve within the upper non-combustion chamber.

[0009] In yet another aspect of the present disclosure, a computer-implemented method for varying displacement of a combustion engine includes controlling, by a controller, timing of an upper intake valve in an upper non-combustion chamber of an engine block of the combustion engine; controlling, by the controller, timing of an upper exhaust valve in the upper non-combustion chamber; and controlling, by the controller, timing of a main valve in a main combustion cylinder of the engine block, wherein the timing of the main valve, the timing of the upper intake valve, and the timing of the upper exhaust valve are controlled independently of one another.

[0010] In yet a further aspect of the present disclosure, a non-transitory computer-readable medium having executable instructions stored thereon for execution by a processor to perform a method for varying displacement of a combustion engine, the method including altering at least one of an upper intake valve timing in an upper non-combustion chamber of an engine block of the combustion engine and an upper exhaust valve timing in the upper non-combustion chamber, and fixing a main valve timing in a main combustion cylinder of the engine block, the main combustion cylinder being in gaseous communication with the upper non-combustion chamber, and wherein the alteration of at least one of the upper intake valve timing and the upper exhaust valve timing is performed independently of each other.

[0011] These and other features, aspects, and advantages of the present disclosure will become more clearly understood with reference to the following drawings, specification, and claims. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a front view of an exemplary embodiment of an engine according to the present disclosure. [Figure 2] FIG. 1 is a top view of an exemplary embodiment of an engine according to the present disclosure. [Figure 3] FIG. 1 is a side view of an exemplary embodiment of an engine according to the present disclosure. [Figure 4] 4 is a cross-sectional view of an exemplary embodiment of an engine according to the present disclosure taken along line 4-4 of FIG. 2. [Figure 5] 1 is a cross-sectional front view of an exemplary embodiment of an engine according to the present disclosure; FIG. [Figure 6] FIG. 1 is a front cross-sectional perspective view of an exemplary embodiment of an engine according to the present disclosure. [Figure 7] FIG. 2 is another cross-sectional front view of an exemplary embodiment of an engine according to the present disclosure. [Figure 8A] FIG. 1 is an enlarged partial cross-sectional view of an exemplary embodiment of an engine according to the present disclosure. [Figure 8B] FIG. 2 is another enlarged partial cross-sectional view of an exemplary embodiment of an engine according to the present disclosure. [Figure 9]1 is a table of a method of operation of an exemplary embodiment of an engine according to the present disclosure. [Figure 10] 1 is a flow chart of an exemplary full-displacement mode and an exemplary partial-displacement mode of operation of an engine according to the present disclosure. [Figure 11] 11A and 11B are valve profiles for an exemplary full flow mode operation of an engine according to the present disclosure, respectively, and are valve profiles for an exemplary full displacement mode operation of an engine according to the present disclosure. [Figure 12] Figure 12A is a series of partial cross-sectional views of an example engine operating in a full displacement mode in accordance with the present disclosure; Figure 12B is a series of partial cross-sectional views of an example engine operating in a full displacement mode in accordance with the present disclosure; Figure 12C is a series of partial cross-sectional views of an example engine operating in a full displacement mode in accordance with the present disclosure; Figure 12D is a series of partial cross-sectional views of an example engine operating in a full displacement mode in accordance with the present disclosure; and Figure 12E is a series of partial cross-sectional views of an example engine operating in a full displacement mode in accordance with the present disclosure. [Figure 13] 1 is a valve profile for an exemplary partial displacement mode of operation of an engine according to the present disclosure. [Figure 14] Figure 14A is a series of partial cross-sectional views of an exemplary partial displacement mode of operation of an engine in accordance with the present disclosure; Figure 14B is a series of partial cross-sectional views of an exemplary partial displacement mode of operation of an engine in accordance with the present disclosure; Figure 14C is a series of partial cross-sectional views of an exemplary partial displacement mode of operation of an engine in accordance with the present disclosure; Figure 14D is a series of partial cross-sectional views of an exemplary partial displacement mode of operation of an engine in accordance with the present disclosure; and Figure 14E is a series of partial cross-sectional views of an exemplary partial displacement mode of operation of an engine in accordance with the present disclosure. [Figure 15] 10 is a valve profile for another exemplary partial displacement mode of operation of an engine in accordance with the present disclosure. [Figure 16] 1 is a valve profile for an exemplary blowback mode of operation of an engine according to the present disclosure. [Figure 17]Figure 17A is a series of partial cross-sectional views of an exemplary blowback mode operation of an engine according to the present disclosure; Figure 17B is a series of partial cross-sectional views of an exemplary blowback mode operation of an engine according to the present disclosure; Figure 17C is a series of partial cross-sectional views of an exemplary blowback mode operation of an engine according to the present disclosure; Figure 17D is a series of partial cross-sectional views of an exemplary blowback mode operation of an engine according to the present disclosure; and Figure 17E is a series of partial cross-sectional views of an exemplary blowback mode operation of an engine according to the present disclosure. [Figure 18] 1 is a flow chart of an exemplary Otto cycle mode and an exemplary Atkinson cycle mode of operation of an engine according to the present disclosure. [Figure 19] FIG. 19A is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19B is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19C is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19D is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19E is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19F is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19G is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19H is a valve profile for an example Otto cycle mode and Atkinson cycle mode operation of an engine according to the present disclosure. FIG. 19I is a valve profile for exemplary Otto and Atkinson cycle modes of operation of an engine according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following detailed description sets forth the best modes presently contemplated for carrying out the present disclosure. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the present disclosure, since the scope of the present disclosure is best defined by the appended claims.

[0014] The various inventive features described below can be used independently of one another or in combination with other features. However, any one inventive feature may address none of the problems described above, or may address only one of the problems described above. Furthermore, one or more of the problems described above may not be completely solved by any of the features described below.

[0015] The technical problem to be solved is to maintain the engine displacement in a single engine with a fixed displacement even when the engine load conditions change.

[0016] Broadly, the present disclosure solves the above problems with the ability to tailor engine displacement on demand by manipulating exhaust and intake gases using variable valve timing. Engines can be manufactured with physically large engine displacements. Engines can be operated as high-power, high-power density engines or as lower-power, low-density engines. Lower-power, low-density operation requires less fuel consumption. The flexibility of the engine allows it to be built larger with larger parts, thereby improving lifespan and reliability.

[0017] The present disclosure further solves the above-mentioned problems by locating the upper exhaust valve and upper intake valve in an upper non-combustion chamber outside the main combustion cylinder. Therefore, there are no advance or retard constraints or limitations on the timing of these two valves. In conventional engines, the intake and exhaust valves are located in the combustion chamber where the piston moves up and down. Piston movement imposes constraints and limitations on the opening and closing of the valves when they share the same combustion chamber. In the present disclosure, because there is no restriction imposed by piston movement, the upper intake and exhaust valves can be designed with larger valve profiles, larger valve lift, and a wider timing range. Additionally, the main valves can have a high flow capacity suitable for performance racing engines.

[0018] As will be appreciated by those skilled in the art, aspects of the present disclosure may be embodied as a system, method, or computer program product. Accordingly, aspects of the present disclosure may take the form of either an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining both software and hardware aspects, which may be collectively referred to herein as a "circuit," "module," or "system." Furthermore, aspects of the present disclosure may take the form of a computer program product embodied as computer-readable program code stored on one or more computer-readable medium(s).

[0019] Any combination of one or more computer-readable storage media may be utilized. A computer-readable storage medium is an electronic, magnetic, optical, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific (non-exhaustive) examples of computer-readable storage media include a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. As used herein, a computer-readable storage medium refers to a tangible medium that can store a program by or in conjunction with an instruction execution system, apparatus, or device.

[0020] A computer-readable signal medium may include a propagated data signal in which computer-readable program code is embodied, for example, in baseband or as part of a carrier wave. Such a propagated signal may take various forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium is not a computer-readable storage medium, but is any computer-readable medium that can communicate, propagate, or carry a program for use by or in connection with an instruction execution system, apparatus, or device.

[0021] The program code embodied in the computer readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, fiber optic cable, RF, etc., or any suitable combination thereof.

[0022] Computer program code for carrying out operations of each aspect of the present disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" programming language or similar programming languages. The program code may run entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on both the user's computer and a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network, such as a local area network (LAN) or wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet Service Provider).

[0023] Aspects of the present disclosure are described below with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions are provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus that generates a machine, and the instructions, executed by the processor of the computer or other programmable data processing apparatus, generate means for implementing the function(s) / acts identified in the block or blocks of the flowchart illustrations and / or block diagrams.

[0024] These computer program instructions may also be stored on a computer-readable storage medium that can cause a computer, other programmable data processing apparatus, or other device to operate in a specific manner, to produce an article of manufacture including instructions that implement the functions / acts identified in the flowchart and / or block diagram block or blocks, with the instructions stored on the computer-readable storage medium.

[0025] The computer program instructions may also be loaded into a computer, other programmable data processing apparatus, or other device and cause the computer, other programmable apparatus, or other device to perform a series of operational steps, thereby providing a process in which the instructions executing on the computer or other programmable apparatus implement the functions / operations identified in the block or blocks of the flowcharts and / or block diagrams.

[0026] 1 and 3 are front and side views, respectively, of an exemplary combustion engine 10 according to one embodiment. The engine 10 may have an engine block 23. In one embodiment, the engine block 23 may include a cylinder block 11 and a cylinder head 12. In one embodiment, the engine 10 may include one or more upper intake valve phasers (i.e., upper intake cam phasers) 13 disposed in an upper region of the cylinder head 12. In one embodiment, the engine 10 may include one or more upper exhaust valve phasers (i.e., upper exhaust cam phasers) 14 disposed in an upper region of the cylinder head 12. In one embodiment, the engine 10 includes one upper intake valve phaser 13 and one upper exhaust valve phaser 14. According to one embodiment, the engine 10 may include one or more main valve sprockets 15 disposed in an upper region of the cylinder head 12 and positioned between the upper intake valve phaser 13 and the upper exhaust valve phaser 14. In one embodiment, the engine 10 includes two main valve sprockets 15 .

[0027] In one embodiment, engine 10 may include a crankshaft sprocket 16 located in a lower region of cylinder block 11. A timing chain 17 may engage crankshaft sprocket 16, a sprocket for upper intake valve phaser 13, a sprocket for upper exhaust valve phaser 14, and a main valve sprocket 15. In one embodiment, engine 10 may include an intake manifold 18 on one side of engine block 23 and an exhaust manifold 19 on the opposite side of engine block 23.

[0028] In one embodiment, the engine 10 may further include a computer or controller 42. The controller 42 may include a processor and a database. In one embodiment, the database may include a settings table that correlates engine load with engine operating modes. In one embodiment, the settings may include advance, retard, and neutral timing settings for the upper intake valve phaser 13 and / or the upper exhaust valve phaser 14 depending on the engine operating mode.

[0029] 2 is a top view of engine 10 according to one embodiment. According to one embodiment, engine 10 may include one or more upper intake camshafts 20 configured to move one or more upper intake valves 32, described below. According to one embodiment, one or more upper intake camshafts 20 may be configured to move one or more upper intake valves 32 within one or more upper non-combustion chambers 30, described below.

[0030] In one embodiment, the one or more upper intake camshafts 20 may be configured to engage one or more upper intake cams 20a. In one embodiment, the upper intake camshafts 20 may engage upper intake valve phasers 13. One or more intake camshaft bearing caps 40a may support the upper intake camshafts 20 on the engine block 23.

[0031] Similarly, engine 10, according to one embodiment, may include one or more upper exhaust camshafts 24 configured to move one or more upper exhaust valves 33, described below. One or more upper exhaust camshafts 24, according to one embodiment, may be configured to move one or more upper exhaust valves 33 within one or more upper non-combustion chambers 30, described below.

[0032] In one embodiment, the one or more upper exhaust camshafts 24 may be configured to engage one or more upper exhaust cams 24a. In one embodiment, the upper exhaust camshafts 24 may engage upper exhaust valve phasers 14. One or more exhaust camshaft bearing caps 40b may support the upper exhaust camshafts 24 on the engine block 23.

[0033] In one embodiment, engine 10 may include one or more main camshafts 21, 25 configured to move one or more main valves 31, described below. In one embodiment, one or more main camshafts 21, 25 may be configured to move one or more main valves 31 within one or more main combustion cylinders 29, described below.

[0034] In one embodiment, the one or more main camshafts 21, 25 may be engaged with one or more primary cams 21a, 25a. In one embodiment, the main camshafts 21, 25 may be engaged with the main valve sprocket 15. One or more main camshaft bearing caps 41 may support the main camshafts 25 on the engine block 23. The engine 10 may include a crankshaft 22 disposed in a lower region of the cylinder block 11 and operatively connected to one or more pistons 34 (FIG. 3), described below.

[0035] FIG. 4 is a cross-sectional view of engine 10 taken along line 4-4 of FIG. 2. In one embodiment, cylinder block 11 may include one or more main combustion cylinders 29 each having a piston 34 therein. In one embodiment, main combustion cylinders 29 may be configured to allow piston 34 to move therein. In one embodiment, one or more main combustion cylinders 29 may be configured to allow combustion of intake air therein and to allow exhaust gases to be expelled. In one embodiment, one or more connecting rods 35 may operatively connect pistons 34 to crankshaft 22.

[0036] In one embodiment, the cylinder head 12 may include one or more upper non-combustion chambers 30. In one embodiment, the one or more upper non-combustion chambers 30 may be operatively adjacent to each of the main combustion cylinders 29. In one embodiment, the one or more upper non-combustion chambers 30 may be in gaseous communication with each of the main combustion cylinders 29. In one embodiment, the one or more upper non-combustion chambers 30 may be configured to operate in intake, compression, and exhaust modes with the one or more main combustion cylinders 29. However, in one embodiment, combustion is not intended to occur in the one or more upper non-combustion chambers 30. According to one embodiment, the one or more upper non-combustion chambers 30 may be configured to receive intake air from outside the engine 10 and to discharge exhaust gases from the one or more main combustion cylinders 29. In one embodiment, the one or more upper non-combustion chambers 30 may be configured to receive exhaust gases from the one or more main combustion cylinders 29.

[0037] According to one embodiment, one or more upper non-combustion chambers 30 may be in gaseous communication with intake manifold 18. According to one embodiment, one or more upper non-combustion chambers 30 may be in gaseous communication with exhaust manifold 19. In one embodiment, each upper non-combustion chamber 30 is in gaseous communication with intake manifold 18 and exhaust manifold 19.

[0038] 4, according to one embodiment, one or more main valves 31 may be configured to move within one or more main combustion cylinders 29. In one embodiment, one or more main valves 31 may be configured to allow air to be drawn into one or more main combustion cylinders 29 and to allow exhaust gases to be exhausted out of one or more main combustion cylinders 29. In other words, the main valves 31 may operate as both intake and exhaust valves.

[0039] In one embodiment, one or more upper exhaust valves 33 may be configured to move within the upper non-combustion chamber 30. In one embodiment, the one or more upper exhaust valves 33 may be configured to allow exhaust gases to exit from one or more main combustion cylinders 29 into the exhaust manifold 19.

[0040] In one embodiment, one or more spark plugs 39 may be operatively associated with one or more main combustion cylinders 29. In one embodiment, each main combustion cylinder 29 has a respective spark plug 39 associated therewith.

[0041] Figure 5 is a cross-sectional plan view of the engine block 23 according to one embodiment. Figure 6 is a cross-sectional perspective view of the engine block 23 shown in Figure 5. Figure 7 is another cross-sectional plan view of the engine block 23.

[0042] 5, in one embodiment, the main camshafts 21, 25 may be operatively connected to one or more main valves 31 via one or more main valve rockers 37. In one embodiment, four main valves 31 may be provided configured to move within one main combustion cylinder 29 (FIG. 6). According to one embodiment, one or more main valves 31 may be configured to operate as a main intake valve and a main exhaust valve within one or more main combustion cylinders 29. At any given time, all of the main valves 31, in one embodiment, are operating as either a main intake valve or a main exhaust valve.

[0043] The one or more main channels 31 a, in one embodiment, may enable the one or more main valves 31 to move between an open position and a closed position of the main valves 31. The one or more main channels 31 a may extend between the one or more main combustion cylinders 29 and the one or more upper non-combustion chambers 30 and provide gas communication therebetween.

[0044] In one embodiment, the upper intake camshaft 20 may be operatively connected to one or more upper intake valves 32. In one embodiment, the one or more upper intake valves 32 may be configured to move within one or more upper non-combustion chambers 30. In one embodiment, two upper intake valves 32 may be provided, each configured to move within one upper non-combustion chamber 30 (FIG. 6). The one or more upper intake valves 32 may be configured to be operatively adjacent to and / or in gaseous communication with the intake manifold 18, according to one embodiment.

[0045] In one embodiment, one or more upper intake valves 32 may be configured to pass intake air from the intake manifold 18 to one or more upper non-combustion chambers 30. In one embodiment, one or more upper intake valves 32 may be configured to pass exhaust gases from one or more main combustion cylinders 29 to the intake manifold 18.

[0046] The one or more upper channels 32a, in one embodiment, may allow the one or more upper intake valves 32 to move between an open position and a closed position of the upper intake valves 32. The one or more upper channels 32a may extend between the one or more upper non-combustion chambers 30 and the intake manifold 18 and provide gaseous communication therebetween.

[0047] In one embodiment, the upper exhaust camshaft 24 may be operatively connected to one or more upper exhaust valves 33. In one embodiment, the one or more upper exhaust valves 33 may be configured to move within one or more upper non-combustion chambers 30. In one embodiment, two upper exhaust valves 33 may be provided, each configured to move within one upper non-combustion chamber 30 (FIG. 6). The one or more upper exhaust valves 33 may be configured to be operatively adjacent to and / or in gaseous communication with the exhaust manifold 19, according to one embodiment.

[0048] The one or more upper channels 33a, in one embodiment, may allow the one or more upper exhaust valves 33 to move between an open position and a closed position of the upper exhaust valves 33. The one or more upper channels 33a may extend between the one or more upper non-combustion chambers 30 and the exhaust manifold 19 to provide gas communication therebetween.

[0049] As described above, in one embodiment, the upper exhaust camshaft 24 is movable via the upper exhaust valve phaser 14, and the upper intake camshaft 20 is movable via the upper intake valve phaser 13. Thus, the upper exhaust camshaft 24 may be configured to move independently of the upper intake camshaft 20 in a timing-controlled manner. Similarly, the upper exhaust valve 33 may be configured to move independently of the upper intake valve 32 in a timing-controlled manner. Because the main camshafts 21, 25 are not connected to the upper exhaust valve phaser 14 or the upper intake valve phaser 13, the main valve 31 may be configured to move independently of the upper exhaust valve 33 and the upper intake valve 32 in a timing-controlled manner. In other words, the upper intake valve timing, upper exhaust valve timing, and main valve timing can operate independently of one another.

[0050] In one embodiment, the upper intake valve 32 and upper exhaust valve 33 may be located near the upper region of the upper non-combustion chamber 30 and outside of the main combustion cylinder 29. As a result, the size of the valves 32, 33 and their valve duration (i.e., opening and closing duration) can be designed independently of the piston position, stroke, and movement.

[0051] 6 and 7, in one embodiment, one or more spark plugs 39 may be operatively disposed within one or more main combustion cylinders 29. In one embodiment, one or more spark plugs 39 may extend through one or more upper non-combustion chambers 30 and into one or more main combustion cylinders 29.

[0052] In one embodiment, one or more fuel injectors 38 may be operatively adjacent to one or more spark plugs 39. In one embodiment, one or more fuel injectors 38 may extend into one or more main combustion cylinders 29. In one embodiment, one fuel injector 38 and one spark plug 39 extend into one main combustion cylinder 29.

[0053] 8A and 8B are enlarged views of the interface between the spark plug 39 and the main combustion cylinder 29 according to two embodiments.

[0054] In FIG. 8A , according to one embodiment, a recess 12a is provided in the lower region of the cylinder head 12. In one embodiment, the recess 12a may be configured to accommodate an electrode end of a spark plug 39. In one embodiment, the recess 12a may be spherical. In one embodiment, the head portion of the piston 34 is provided with a recess 34a. In one embodiment, the recess 34a faces the recess 12a, and the recesses are open so that they face each other. In one embodiment, the recess 34a may have the same shape as the recess 12a. In one embodiment, the recess 34a may be spherical.

[0055] In Figure 8B, the recess 12a of the cylinder head 12 is the same as in Figure 8A, but in this embodiment, the piston 34 does not have the recess 34a.

[0056] In the embodiments of Figures 8A and 8B, recesses 12a and / or 34a (including spherical combustion chambers) may shorten fuel burn time and allow for uniform combustion from the center outward. More complete combustion may also be achieved, thereby improving efficiency. Furthermore, stroke ignition may occur at the center of the piston head, allowing for direct power transmission to the piston head.

[0057] 9 is a chart illustrating exemplary operating modes of combustion engine 10. In one embodiment, engine 10 can operate between a full engine displacement mode and a partial engine displacement mode. According to one embodiment, in full engine displacement mode, engine 10 can operate at a maximum engine displacement. According to one embodiment, in partial engine displacement mode, engine 10 can operate at less than the maximum engine displacement.

[0058] Full engine and partial engine displacement modes can be achieved by configuring the main valve 31, upper intake valve 32, and upper exhaust valve 33 to operate in these two modes, according to one embodiment. Depending on whether the mode is full engine displacement or partial engine displacement, the timing of the upper intake valve 32 and upper exhaust valve 33 can be individually adjusted / controlled to be advanced, retarded, or neutral, according to one embodiment (FIG. 9). The timing of the main valve 31 can be adjusted / controlled to maintain a fixed timing, according to one embodiment.

[0059] 9, in one embodiment, engine 10 can operate between an Atkinson cycle mode and an Otto cycle mode. According to one embodiment, in the Atkinson cycle mode, engine 10 can operate with the piston compression stroke shorter than the piston expansion stroke. According to one embodiment, in the Otto cycle mode, engine 10 can operate with the piston compression stroke equal to the piston expansion stroke.

[0060] According to one embodiment, the Atkinson cycle mode and the Otto cycle mode can be achieved by configuring the main valve 31, the upper intake valve 32, and the upper exhaust valve 33 to operate in these two modes. Depending on whether the mode is the Atkinson cycle mode or the Otto cycle mode, the timing of the upper intake valve 32 and the upper exhaust valve 33 can be individually adjusted / controlled to be advanced, retarded, or neutral, according to one embodiment (FIG. 9). At the same time, the timing of the main valve 31 can be adjusted / controlled to maintain a fixed timing, according to one embodiment.

[0061] In other embodiments, engine 10 may operate in a full engine displacement mode in Otto cycle mode, a partial engine displacement mode in Otto cycle mode, a full engine displacement mode in Atkinson cycle mode, and a partial engine displacement mode in Atkinson cycle mode.

[0062] In one embodiment, engine 10 can operate in a blowback mode. In this mode, engine 10 can operate with exhaust gases from main combustion cylinder 29 discharged into upper non-combustion chamber 30 and subsequently into intake manifold 18. Upper intake valve 32, in one embodiment, can be configured to transfer exhaust gases into intake manifold 18. The timing of upper intake valve 32 and upper exhaust valve 33 can be individually adjusted / controlled to advance, retard, or neutral, according to one embodiment, to achieve blowback mode. The timing of main valve 31, in one embodiment, can be adjusted / controlled to maintain a fixed timing.

[0063] 1, 10, and 18, the present disclosure provides a computer-implemented method for varying the displacement of a combustion engine 10. A controller 42 may be used to implement one or more of the operating modes described above. Thus, it will be appreciated that the controller 42, according to one embodiment, may be configured to control the timing of the upper intake valve 32 in the upper non-combustion chamber 30, the timing of the main valve 31 in the main combustion cylinder 29, and the timing of the upper exhaust valve 33 in the upper non-combustion chamber 30. The controller 42 may be configured to perform these timing controls independently or separately from one another.

[0064] In one embodiment, the controller 42 may be configured to control the timing of the upper intake valve 32 and the upper exhaust valve 33, including advanced, retarded, or neutral timing. At the same time, in one embodiment, the controller 42 may be configured to control the timing of the main valve 31, including maintaining a fixed timing for the main valve 31. The timing of the upper intake valve 32 and the main valve 31 allows intake air to enter the upper non-combustion chamber 30 and pass into the main combustion cylinder 29. Similarly, the timing of the upper exhaust valve 33 and the main valve 31 allows exhaust gases to pass from the main combustion cylinder 29 into the upper non-combustion chamber 30 and out of the upper non-combustion chamber 30.

[0065] 1 , 10 , and 18 , the present disclosure provides a non-transitory computer-readable medium having stored thereon executable instructions that are executed by a processor to perform a method for varying the displacement of a combustion engine 10. In one embodiment, the method may include varying at least one of the timing of an upper intake valve 32 in an upper non-combustion chamber 30 and the timing of an upper exhaust valve 33 in the upper non-combustion chamber 30. In one embodiment, the method may include fixing the timing of a main valve 31 in a main combustion cylinder 29. In one embodiment, the method may include allowing the main combustion cylinder 29 to be in gaseous communication with the upper non-combustion chamber 30. In one embodiment, the method may include varying the timing of the upper intake valve 32 and the timing of the upper exhaust valve 33 independently of one another.

[0066] It is understood that in the method and computer readable medium, the combustion engine 10 can operate in a full engine displacement mode, a partial engine displacement mode, an Atkinson cycle mode, an Otto cycle mode, and a blowback mode. [Example]

[0067] 10 illustrates a method 50 for changing engine mode to either full engine displacement or partial engine displacement, according to one embodiment. Method 50 may begin by determining engine load at step 52, such as via an accelerator pedal position sensor, a mass air flow (MAF) sensor, an engine RPM (revolutions per minute) sensor, a wheel speed sensor, and a manifold absolute pressure (MAP) sensor on intake manifold 18. At step 53, controller 42 may determine, for example, whether full engine load is being requested.

[0068] If step 53 is "yes," then in step 54 it is determined to implement full engine displacement mode, for example, by controller 42. In step 55, the upper exhaust valve 33 may be adjusted to neutral timing, for example, by controller 42 controlling upper exhaust valve phaser 14. In step 56, the fuel injection rate may be adjusted to a normal rate, for example, by controller 42 controlling fuel injector 38.

[0069] If step 53 is "no," then in step 57, a determination is made to implement partial engine displacement mode, e.g., by controller 42. In step 58, the upper exhaust valve 33 may be adjusted to an advanced timing, e.g., by controller 42 controlling upper exhaust valve phaser 14. In step 60, the fuel injection rate may be adjusted to a lower rate, e.g., by controller 42 controlling fuel injector 38. Following step 57, in step 59, the upper exhaust valve 33 may be adjusted to a retarded timing, e.g., by controller 42 controlling upper exhaust valve phaser 14. In step 61, the fuel injection rate may be adjusted to a lower rate, e.g., by controller 42 controlling fuel injector 38.

[0070] 11A is a valve profile for combustion engine 10 operating at maximum intake and exhaust gas flow. "TDC" and "BDC" refer to the top dead center and bottom dead center positions of piston 34, respectively. Upper intake valve 32 and upper exhaust valve 33 are both set to neutral timing and can be in phase (i.e., overlapping) with the timing of main valve 31, allowing maximum gas flow.

[0071] 11B illustrates a valve profile for the combustion engine 10 operating in full-displacement mode. For example, the engine 10 may be a 2.0-liter, four-stroke engine. The upper intake valve 32 and the upper exhaust valve 33 may both be set to neutral timing and in-phase (i.e., overlapping) with the timing of the main valve 31. However, the upper intake valve 32 and the upper exhaust valve 33 have a longer valve opening period than the main valve 31. On the exhaust stroke, the upper exhaust valve 33 opens just before the main valve 31 opens and closes just after TDC on the intake stroke. On the intake stroke, the upper intake valve 32 opens just before TDC and closes just after BDC.

[0072] 12A-12E are diagrams illustrating intake air 44 and exhaust gases 43 during a series of strokes of engine 10 in full displacement mode. For example, engine 10 may be a 2.0 liter, four-stroke cycle engine.

[0073] 12A shows the exhaust stroke of the previous cycle. After BDC, the main valve 31 opens. The upper exhaust valve 33 opens. The upward movement of the piston 34 pushes exhaust gases 43 out of the main combustion cylinder 29 into the upper non-combustion chamber 30 and into the exhaust manifold 19.

[0074] 12B shows the latter part of the exhaust stroke of the previous cycle. The upper exhaust valve 33 remains open. Further upward movement of the piston 34 forces the remaining exhaust gases 43 into the upper non-combustion chamber 30. The upper intake valve 32 begins to open, and the incoming intake air 44 pushes the exhaust gases 43 out of the upper non-combustion chamber 30, through the upper exhaust valve 33, and into the exhaust manifold 19.

[0075] 12C shows the intake stroke of the next cycle. At the start of the intake stroke, the upper exhaust valve 33 closes and the main valve 31 opens. The downward movement of the piston 34 draws intake air 44 into the main combustion cylinder 29.

[0076] 12D shows the compression stroke of the next cycle. Intake air 44 is compressed in the main combustion cylinder 29 and is ready for combustion.

[0077] 12E shows the power stroke of the next cycle. The upper intake valve 32 and upper exhaust valve 33 close. The main valve 31 closes. Combustion pushes the piston 34 downward, causing the crankshaft 22 to rotate.

[0078] 13 illustrates a valve profile for a combustion engine 10 operating in partial displacement mode using advanced timing. The upper intake valve 32 is set to neutral timing and may be in phase (i.e., overlapping) with the timing of the main valve 31. The upper exhaust valve 33 is set to advanced timing. Advancing the timing of the upper exhaust valve 33 allows the upper exhaust valve 33 to open and close before the main valve 31 opens and closes. Advancing the timing of the upper exhaust valve 33 reduces overlap with the main valve 31 during the exhaust cycle. The amount of advance of the upper exhaust valve 33 determines the amount of exhaust gas 43 that can be collected and retained in the upper non-combustion chamber 30.

[0079] 14A-14E are diagrams illustrating intake air 44 and exhaust gases 43 during a series of strokes of engine 10 in partial displacement mode with upper exhaust valve 33 advanced.

[0080] 14A shows the exhaust stroke of the previous cycle. The upper exhaust valve 33 opens before BDC. The main valve 31 opens just after BDC. The upward movement of the piston 34 pushes exhaust gases 43 out of the main combustion cylinder 29 into the upper non-combustion chamber 30 and into the exhaust manifold 19.

[0081] 14B shows the latter part of the exhaust stroke of the previous cycle. The upper exhaust valve 33 and upper intake valve 32 close. While the main valve 31 is open, further upward movement of the piston 34 forces remaining exhaust gases 43 into the upper non-combustion chamber 30.

[0082] 14C shows the intake stroke of the next cycle. The upper intake valve 32 opens just before TDC and just before the start of the intake stroke. At the start of the intake stroke, the upper exhaust valve 33 closes and the main valve 31 opens. The downward movement of the piston 34 draws exhaust gases 43 from the upper non-combustion chamber 30, and subsequently, intake air 44 is drawn from the upper non-combustion chamber 30 into the main combustion cylinder 29. The exhaust gases 43 in the upper non-combustion chamber 30 can replace a portion of the incoming intake air 44.

[0083] Figure 14D shows the compression stroke of the next cycle. All valves are closed. Intake air 44 is compressed in the main combustion cylinder 29 along with exhaust gases 43, ready for combustion.

[0084] 14E shows the power stroke of the next cycle. The upper intake valve 32 and upper exhaust valve 33 close. The main valve 31 closes. Combustion pushes the piston 34 downward, causing the crankshaft 22 to rotate.

[0085] 15 illustrates a valve profile for a combustion engine 10 operating in partial displacement mode using retarded timing. The upper intake valve 32 is set to neutral timing and may be in phase (i.e., overlapping) with the timing of the main valve 31. The upper exhaust valve 33 is set to retarded timing. Retarding the timing of the upper exhaust valve 33 allows the upper exhaust valve 33 to open and close after the main valve 31 opens and closes. Retarding the timing of the upper exhaust valve reduces overlap with the main valve 31 during the exhaust cycle. The amount that the upper exhaust valve 33 is retarded determines the amount of exhaust gas 43 that can be collected and retained in the upper non-combustion chamber 30.

[0086] In partial displacement mode, as shown in FIGS. 13 and 15, the timing of the upper exhaust valve 33 determines the amount of exhaust gas 43 collected (i.e., trapped) in the upper non-combustion chamber 30. The more advanced or retarded the timing, the greater the amount of exhaust gas 43 collected in the upper non-combustion chamber 30. The more exhaust gas 43 collected, the greater the amount of intake air 44 displaced from the upper non-combustion chamber 30. By using exhaust gas 43 to displace intake air 44, for example, a 2.0-liter engine can operate as a 1.0-liter engine if the upper non-combustion chamber 30 is filled with 1.0 liter of intake air 44 and 1.0 liter of exhaust gas 43. Because exhaust gas 43 cannot be burned twice, the required fuel volume is based on the 1.0 liter of intake air 44. The compression ratio of a 2.0-liter engine burning 2.0 liters of intake air 44 is similar to the compression ratio of an engine burning 1.0 liters of intake air 44 and 1.0 liter of exhaust gas 43. However, the latter saves fuel consumption.

[0087] 16 shows the valve profile for the combustion engine 10 operating in blowback mode. The upper intake valve 32 is set to neutral timing and may be in phase (i.e., overlapping) with the timing of the main valve 31. The upper exhaust valve 33 is set to advanced timing. The upper exhaust valve 33 is allowed to open before BDC (bottom dead center). There is some overlap between the upper exhaust valve 33 and the main valve 31.

[0088] The upper intake valve 32 can have a longer valve opening duration than the main valve 31. A longer upper intake valve 32 opening duration can result in a greater overlap between the upper intake valve 32 and the main valve 31 opening durations later in the exhaust stroke. Alternatively, the upper intake valve 32 can be advanced to increase the overlap with the upper exhaust valve 33 timing. To allow exhaust gases 43 to flow from the main combustion cylinder 29 into the upper non-combustion chamber 30 and into the intake manifold 18, the upper intake valve 32 can be opened before the intake stroke to allow sufficient time for the exhaust gases 43 to flow back into the intake manifold 18.

[0089] 17A-17E are diagrams illustrating the intake air 44 and exhaust gases 43 during a series of strokes of the engine 10 in blowback mode. The blowback mode can be used in combustion engines 10 designed with a small upper non-combustion chamber 30.

[0090] 17A shows the exhaust stroke of the previous cycle. The upward movement of the piston 34 forces exhaust gases 43 into the upper non-combustion chamber 30 and out the exhaust manifold 19.

[0091] 17B shows the latter part of the exhaust stroke of the previous cycle. The early closing of the upper exhaust valve 33 and the early opening of the upper intake valve 32 cause exhaust gases 43 to flow into the upper non-combustion chamber 30 and then into the intake manifold 18. At that point, the intake manifold 18 acts as a reservoir of exhaust gases 43 and intake air 44 to be used in the next cycle.

[0092] 17C shows the intake stroke of the next cycle. The downward movement of the piston 34 draws exhaust gases 43 and intake air 44 from the intake manifold 18 through the upper non-combustion chamber 30 and into the main combustion cylinder 29.

[0093] Figure 17D shows the compression stroke of the next cycle. All valves are closed. Intake air 44 is compressed in the main combustion cylinder 29 along with exhaust gases 43, ready for combustion.

[0094] 17E shows the power stroke of the next cycle. All valves are closed. Combustion pushes the piston 34 downward, rotating the crankshaft 22.

[0095] 18 is a flowchart of a method 70 for changing engine mode to either Otto cycle mode or Atkinson cycle mode, according to one embodiment. Method 70 may begin in step 72 by determining engine performance from an accelerator pedal position sensor, engine RPM sensor, mass air flow (MAF) sensor, wheel speed sensors, etc. In step 73, controller 42 may determine, for example, whether maximum horsepower output is desired.

[0096] If step 73 is "yes," then in step 74 it is determined to implement Otto cycle mode, for example, by controller 42. In step 75, upper intake valve 32 may be adjusted to neutral timing, for example, by controller 42 controlling upper intake valve phaser 13. In step 76, the fuel injection rate may be adjusted to a normal rate, for example, by controller 42 controlling fuel injector 38.

[0097] If step 73 is "No," then in step 77, it is determined, for example, by the controller 42, that the Atkinson cycle mode is to be implemented. In step 78, the upper intake valve 32 may be adjusted to an advanced timing, for example, by the controller 42 controlling the upper intake valve phaser 13. In step 80, the fuel injection rate may be adjusted to a lower rate, for example, by the controller 42 controlling the fuel injector 38. Following step 77, instead of step 78, in step 79, the upper intake valve 32 may be adjusted to a retarded timing, for example, by the controller 42 controlling the upper intake valve phaser 13. In step 81, the fuel injection rate may be adjusted to a lower rate, for example, by the controller 42 controlling the fuel injector 38.

[0098] FIG. 19A is a valve profile for combustion engine 10 operating in Atkinson cycle mode with exhaust and intake advance.

[0099] Advancing the timing of the upper exhaust valve 33 during the power / exhaust stroke results in an earlier valve opening during the power stroke and an earlier closing during the exhaust stroke. The earlier opening of the upper exhaust valve 33 during the power stroke does not affect engine operation. However, the earlier closing of the upper exhaust valve 33 during the exhaust stroke limits and restricts the amount of exhaust gases 43 that can exit the engine block 11 through the main valve 31 and upper exhaust valve 33. The earlier closing of the upper exhaust valve 33 causes exhaust gases 43 to remain in the upper non-combustion chamber 30, causing some exhaust gases 43 to "blow back" into the intake manifold 18 when the upper intake valve 32 opens. The exhaust gases 43 can remain in the intake manifold 18 until the intake stroke occurs.

[0100] Gases require the entire intake stroke to fill the main combustion cylinder 29 through the main valve 31 and upper intake valve 33. By advancing the closing of the upper intake valve 32 during the intake stroke, the amount of gas entering the main combustion cylinder 29 for compression is reduced, making the compression stroke shorter than the expansion stroke, as in an Atkinson engine.

[0101] During the intake stroke, exhaust gases 43 present in the upper non-combustion chamber 30 are re-introduced into the main combustion cylinder 29 via the main valve 31. The presence of exhaust gases 43 in the main combustion cylinder 29 acts as a filler to displace intake air 44. The more exhaust gases 43 present in the upper non-combustion chamber 30 during the intake stroke, the more intake air 44 is displaced, and therefore less fuel is required to combust with the intake air 44. And vice versa. The presence of exhaust gases 43 in the upper non-combustion chamber 30 and the intake manifold 18 results in partial displacement.

[0102] FIG. 19B is a valve profile for combustion engine 10 operating in Otto cycle mode with exhaust advance and intake neutral.

[0103] Advancing the timing of the upper exhaust valve 33 during the power / exhaust stroke results in an earlier valve opening during the power stroke and an earlier closing during the exhaust stroke. The earlier opening of the upper exhaust valve 33 during the power stroke does not affect engine operation. However, the earlier closing of the upper exhaust valve 33 during the exhaust stroke limits and restricts the amount of exhaust gases 43 that can exit the engine block 11 through the main valve 31 and upper exhaust valve 33. The earlier closing of the upper exhaust valve 33 causes exhaust gases 43 to remain in the upper non-combustion chamber 30, causing some exhaust gases 43 to "blow back" into the intake manifold 18 when the upper intake valve 32 opens. The exhaust gases 43 can remain in the intake manifold 18 until the intake stroke occurs.

[0104] When the timing of the upper exhaust valve 33 is advanced significantly, the volume of exhaust gas 43 present in the upper non-combustion chamber 30 increases. When the timing of the upper exhaust valve 33 is advanced to a minimum, the volume of exhaust gas 43 in the upper non-combustion chamber 30 decreases.

[0105] During the intake stroke, exhaust gases 43 present in the upper non-combustion chamber 30 are re-introduced into the main combustion cylinder 29 through the main valve 31. The downward force of the piston 34 draws the exhaust gases 43 from the upper non-combustion chamber 30 and intake air 44 from the intake manifold 18 into the main combustion cylinder 29 through the main valve 31 and upper intake valve 32. The presence of the exhaust gases 43 in the main combustion cylinder 29 acts as a filler, displacing the intake air 44. The exhaust gases 43 do not burn. Therefore, the more exhaust gases 43 present in the upper non-combustion chamber 30 during the intake stroke, the more intake air 44 is displaced, and therefore less fuel is required to combust with the intake air 44. Vice versa. Because the exhaust gases 43 displaced a portion of the intake air 44 during the intake and compression strokes, the engine operates in partial displacement mode.

[0106] Because the timing of the upper intake valve 32 is neutral, there is no limit or shortening of the intake stroke duration and the engine operates in Otto cycle mode.

[0107] FIG. 19C is a valve profile for combustion engine 10 operating in Atkinson cycle mode with exhaust advance and intake retard.

[0108] By advancing the timing of the upper exhaust valve 33, exhaust gases 43 are present in the upper non-combustion chamber 30 at the beginning of the intake stroke. This causes the exhaust gases 43 to displace intake air 44 in the main combustion cylinder 29 during the intake and compression strokes. The presence of exhaust gases 43 in the main combustion cylinder 29 during the compression stroke changes the engine from full displacement to partial displacement.

[0109] Retarding the timing of the upper intake valve 32 delays its opening during the intake stroke. This delay shortens the time available for gas to flow through the upper intake valve 32 and main valve 31 into the main combustion cylinder 29 to fill it. This increases the velocity of gas from the upper non-combustion chamber 30 and intake manifold 18 to fill the main combustion cylinder 29. Further retarding the upper intake valve also reduces the amount of gas available from the upper non-combustion chamber 30 and intake manifold 18 to flow through the upper intake valve 32 and main valve 31 into the main combustion cylinder 29. During the intake stroke, gas requires the entire intake stroke to fill the main combustion cylinder. Therefore, increasing the retardation of the upper intake valve 32 shortens the time available for gas to flow through the upper intake valve 32 and main valve 31 into the main combustion cylinder 29 to fill it. This reduces the amount of gas compressed during the compression stroke, making the compression stroke shorter than the expansion stroke, as in an Atkinson engine.

[0110] FIG. 19D is a valve profile for combustion engine 10 operating in Atkinson cycle mode with exhaust neutral and intake advanced.

[0111] The neutral timing of the upper exhaust valve 33 allows exhaust gases 43 to completely flow from the main combustion cylinder 29 through the main valve 31 into the upper non-combustion chamber 30. The advanced timing of the upper intake valve 32 allows the upper intake valve 32 to open during the exhaust stroke. The overlap of the upper exhaust valve 33 and the upper intake valve 32 simultaneously opens the upper intake valve 32, creating an effect of drawing high-velocity exhaust gases 43 through the upper intake valve 32, the upper non-combustion chamber 30, and the upper exhaust valve 33 into the exhaust manifold 19. The intake air 44 displaces the exhaust gases 43 in the upper non-combustion chamber 30, and the exhaust gases 43 exits the engine 10 through the upper exhaust valve 33. Further advancing the upper intake valve 32 allows more intake air 44 to enter the exhaust manifold 19, which reduces the overall exhaust system temperature and increases the oxygen content in the exhaust system.

[0112] During the intake stroke, gases require the entire intake stroke to fill the main combustion cylinder 29 through the main valve 31 and upper intake valve 32. The advanced timing of the upper intake valve 32 causes it to close earlier during the intake stroke. This reduces the amount of gases entering the main combustion cylinder 29, resulting in a shorter compression stroke than the expansion stroke, similar to an Atkinson engine. Because no exhaust gases 43 are present in the upper non-combustion chamber 30 and intake manifold 18 during the intake stroke, the engine operates at full capacity.

[0113] FIG. 19E is a valve profile for combustion engine 10 operating in Atkinson cycle mode with exhaust neutral and intake retard.

[0114] The neutral timing of the upper exhaust valve 33 allows exhaust gases 43 to be completely expelled from the main combustion cylinder 29 via the main valve 31 and upper exhaust valve 33. If the upper intake valve 32 is timed too far and there is no overlap between the upper exhaust valve 33 and the upper intake valve 32, exhaust gases 43 will remain in the upper non-combustion chamber 30 and re-enter the main combustion cylinder 29 during the intake stroke, resulting in partial displacement operation of the engine.

[0115] Retarding the timing of the upper intake valve 32 delays the opening of the upper intake valve 32 during the intake stroke. This delay shortens the time period during which gas can flow into and fill the main combustion cylinder 29 through the upper intake valve 32 and main valve 31. When the upper intake valve 32 opens, the downward force of the piston 34 creates a vacuum within the main combustion cylinder 29, increasing the rate at which gas flows from the upper non-combustion chamber 30 and intake manifold 18 through the main valve 31 and upper intake valve 32 to fill the main combustion cylinder 29. Further retarding the timing of the upper intake valve 32 reduces the amount of gas that can flow from the upper non-combustion chamber 30 and intake manifold 18 through the upper intake valve 32 and main valve 31 into the main combustion cylinder 29. During the intake stroke, gas requires the entire intake stroke to fill the main combustion cylinder. Therefore, by increasing the retardation of the upper intake valve 32, the period during which gas flows through the upper intake valve 32 and the main valve 31 into the main combustion cylinder 29 and fills it is shortened. This reduces the amount of gas compressed during the compression stroke, making the compression stroke shorter than the expansion stroke, as in an Atkinson engine.

[0116] FIG. 19F is a valve profile for combustion engine 10 operating in Otto cycle mode with exhaust neutral and intake neutral.

[0117] The neutral timing of the upper intake valve 32 allows the upper intake valve 32 to open later in the exhaust stroke. The neutral timing of the upper exhaust valve 33 allows the upper exhaust valve 33 to close earlier in the intake stroke, creating an overlap in opening between the upper exhaust valve 33 and the upper intake valve 32. The overlap allows high velocity exhaust gas 43 to draw intake air 44 from the intake manifold 18 into the exhaust manifold 19, displacing the exhaust gas 43 in the upper non-combustion chamber 30.

[0118] Neutral timing of the upper exhaust valve 33 and upper intake valve 32 causes the engine to operate in an Otto cycle with equal compression and expansion ratios at full displacement.

[0119] FIG. 19G is a valve profile for combustion engine 10 operating in Atkinson cycle mode with exhaust retard and intake advance.

[0120] The exhaust stroke takes its entire duration to expel exhaust gases 43 from the main combustion cylinder 29 through the main valve 31, upper non-combustion chamber 30, and upper exhaust valve 33 and out of the engine block 11. Retarding the timing of the upper exhaust valve 33 delays the flow of exhaust gases 43 from the upper non-combustion chamber 30 through the upper exhaust valve 33 and into the exhaust manifold 19. Delaying the opening of the upper exhaust valve 33 pressurizes the exhaust gases 43 within the upper non-combustion chamber 30 until the upper exhaust valve 33 opens. Once the upper exhaust valve 33 opens, the exhaust gases 43 flow from the upper non-combustion chamber 30 through the upper exhaust valve 33 and into the exhaust manifold 19 at a higher-than-normal velocity. Because the upper exhaust valve 33 is only open for a short period of time during the exhaust stroke, exhaust gases 43 remain in the upper non-combustion chamber 30 and are reintroduced into the main combustion cylinder 29 through the main valve 31 during the intake stroke, resulting in a partial exhaust volume.

[0121] By advancing the upper intake valve 32, the upper intake valve 32 can open earlier during the exhaust stroke, shortening the open period during the intake stroke. This shortens the period during which intake air 44 fills the main combustion cylinder 29 through the upper intake valve 32 and main valve 31, creating an Atkinson-like effect.

[0122] FIG. 19H is a valve profile for combustion engine 10 operating in Otto cycle mode with exhaust retard and intake neutral.

[0123] The exhaust stroke takes its entire duration to expel exhaust gases 43 from the main combustion cylinder 29 through the main valve 31, upper non-combustion chamber 30, and upper exhaust valve 33 and out of the engine. Retarding the timing of the upper exhaust valve 33 delays the flow of exhaust gases 43 from the upper non-combustion chamber 30 into the exhaust manifold 19. Delaying the opening of the upper exhaust valve 33 pressurizes the exhaust gases 43 within the upper non-combustion chamber 30 until the upper exhaust valve 33 opens. Upon opening, the exhaust gases 43 flow from the upper non-combustion chamber 30 through the upper exhaust valve 33 and into the exhaust manifold 19 at a higher-than-normal velocity. Due to the short opening duration of the upper exhaust valve 33 during the exhaust stroke, exhaust gases 43 remain within the upper non-combustion chamber 30. The exhaust gases 43 are reintroduced into the main combustion cylinder 29 through the main valve 31 during the intake stroke, resulting in a partial exhaust volume. The overlap of opening between the upper exhaust valve 33 and the upper intake valve 32 occurs mainly during the intake stroke, so that exhaust gases 43 are present in the upper non-combustion chamber 30 during the intake stroke.

[0124] The neutral timing of the upper intake valve 32 ensures a gas inlet period throughout the intake stroke, so that the compression stroke and expansion stroke are equal, as in an Otto engine.

[0125] FIG. 19I is a valve profile for combustion engine 10 operating in Atkinson cycle mode with exhaust retard and intake retard.

[0126] The exhaust stroke takes its entire duration to expel exhaust gases 43 from the main combustion cylinder 29 through the main valve 31, upper non-combustion chamber 30, and upper exhaust valve 33 and out of the engine. Retarding the timing of the upper exhaust valve 33 delays the flow of exhaust gases 43 from the upper non-combustion chamber 30 into the exhaust manifold 19. Delaying the opening of the upper exhaust valve 33 pressurizes the exhaust gases 43 within the upper non-combustion chamber 30 until the upper exhaust valve 33 opens. Upon opening, the exhaust gases 43 flow from the upper non-combustion chamber 30 through the upper exhaust valve 33 and into the exhaust manifold 19 at a higher-than-normal velocity. Because the upper exhaust valve 33 is only open for a short period during the exhaust stroke, exhaust gases 43 remain within the upper non-combustion chamber 30 during the intake stroke. The exhaust gases 43 are then reintroduced into the main combustion cylinder 29 through the main valve 31 during the intake stroke, resulting in a partial exhaust volume. The overlap of opening between the upper exhaust valve 33 and the upper intake valve 32 occurs mainly during the intake stroke, so that exhaust gases 43 are present in the upper non-combustion chamber 30 during the intake stroke.

[0127] Retarding the upper intake valve 32 timing shortens the period during which intake air 44 is drawn from the intake manifold 18 into the main combustion cylinder 29 through the upper intake valve 32 and main valve 31. Reducing the overall gas flow into the main combustion cylinder 29 during the intake stroke shortens the ratio of the compression ratio to the expansion ratio, as in the Atkinson cycle.

[0128] Of course, it should be understood that the foregoing relates to exemplary embodiments of the present disclosure and that modifications may be made without departing from the scope of the present disclosure as set forth in the following claims.

Claims

1. a main combustion cylinder configured with a piston movable therein; a main valve configured to move within the main combustion cylinder; an upper non-combustion chamber operatively adjacent said main combustion cylinder; an upper intake valve configured to move within the upper non-combustion chamber and communicate with an intake manifold; an upper exhaust valve configured to move within the upper non-combustion chamber and communicate with an exhaust manifold; A combustion engine comprising:

2. 10. The combustion engine of claim 1, further comprising a main camshaft operatively connected to said main valve.

3. 3. The combustion engine of claim 1 or 2, further comprising an upper intake camshaft operatively connected to the upper intake valve.

4. 4. A combustion engine according to any one of claims 1 to 3, further comprising an upper exhaust camshaft operatively connected to the upper exhaust valve.

5. a plurality of main valves configured to move within the main combustion cylinder; a plurality of upper intake valves configured to move within the upper non-combustion chamber; a plurality of upper exhaust valves configured to move within the upper non-combustion chamber; A combustion engine according to any one of claims 1 to 4, further comprising:

6. A combustion engine according to any one of claims 1 to 5, wherein the upper non-combustion chamber is in gaseous communication with the main combustion cylinder.

7. a main combustion cylinder; a main valve in the main combustion cylinder; an upper non-combustion chamber in gaseous communication with the main combustion cylinder; an upper intake valve in the upper non-combustion chamber; an upper exhaust valve in the upper non-combustion chamber; A combustion engine comprising: A combustion engine, wherein the main valve, the upper intake valve, and the upper exhaust valve are configured to move independently of one another in a timed manner.

8. 8. The combustion engine of claim 7, wherein the main combustion cylinder is configured to allow combustion of intake air therein.

9. 9. A combustion engine according to claim 7 or 8, wherein the main valves are configured to operate as main intake and exhaust valves within the main combustion cylinder.

10. The upper non-combustion chamber is It receives intake air from outside the combustion engine, A combustion engine according to any one of claims 7 to 9, arranged to discharge exhaust gases from the main combustion cylinder.

11. the main valve, the upper intake valve, and the upper exhaust valve are configured to operate in a full engine displacement mode and a partial engine displacement mode; In the full engine displacement mode, the combustion engine operates at maximum combustion engine displacement; A combustion engine according to any one of claims 7 to 10, wherein in the partial engine displacement mode the combustion engine operates at less than maximum combustion engine displacement.

12. the main valve, the upper intake valve, and the upper exhaust valve are configured to operate in a blowback mode; A combustion engine according to any one of claims 7 to 11, wherein in the blowback mode, the upper intake valve is further configured to transfer exhaust gases to an intake manifold.

13. the main valve, the upper intake valve, and the upper exhaust valve are configured to operate in an Otto cycle mode and an Atkinson cycle mode; In the Otto cycle mode, the combustion engine operates in a manner such that the piston compression stroke is equal to the piston expansion stroke; A combustion engine according to any one of claims 7 to 12, wherein in the Atkinson cycle mode, the piston compression stroke is shorter than the piston expansion stroke.

14. a main combustion cylinder; a main valve in the main combustion cylinder; an upper non-combustion chamber configured to operate in an intake mode, a compression mode, and an exhaust mode with the main combustion cylinder; an upper intake valve in the upper non-combustion chamber; an upper exhaust valve in the upper non-combustion chamber; A combustion engine comprising:

15. The combustion engine of claim 14 further comprising an intake manifold in gaseous communication with the upper non-combustion chamber.

16. 16. A combustion engine according to claim 14 or 15, further comprising an exhaust manifold in gaseous communication with the upper non-combustion chamber.

17. A combustion engine according to any one of claims 14 to 16, further comprising a main camshaft arranged to move the main valve in the main combustion cylinder.

18. A combustion engine according to any one of claims 14 to 17, further comprising an upper intake camshaft configured to move the upper intake valve in the upper non-combustion chamber.

19. A combustion engine according to any one of claims 14 to 18, further comprising an upper exhaust camshaft configured to move the upper exhaust valve in the upper non-combustion chamber.

20. 20. A combustion engine according to any one of claims 14 to 19, wherein the main valve is configured to allow air to be admitted into the main combustion cylinder and to allow exhaust gases to be expelled out of the main combustion cylinder.

21. 1. A computer-implemented method for varying the displacement of a combustion engine, comprising: controlling, with a controller, the timing of an upper intake valve in an upper non-combustion chamber of an engine block of the combustion engine; controlling timing of an upper exhaust valve in the upper non-combustion chamber with the controller; controlling the timing of main valves in main combustion cylinders of the engine block with the controller; Including, The method wherein the main valve timing, the upper intake valve timing, and the upper exhaust valve timing are controlled independently of each other.

22. 22. The method of claim 21, wherein controlling the timing of the upper intake valve includes advancing or retarding the timing of the upper intake valve.

23. 23. The method of claim 21 or 22, wherein controlling the timing of the upper exhaust valve comprises advancing or retarding the timing of the upper exhaust valve.

24. A method according to any one of claims 21 to 23, wherein controlling the timing of the main valve comprises maintaining a fixed timing of the main valve.

25. timing the upper intake valve and the main valve to allow intake air to enter the upper non-combustion chamber and pass into the main combustion cylinder; timing said upper exhaust valve and said main valve to allow exhaust gases to pass from said main combustion cylinder into said upper non-combustion chamber and out of said upper non-combustion chamber; The method of any one of claims 21 to 24, further comprising:

26. 1. A non-transitory computer-readable medium having executable instructions stored thereon for execution by a processor for performing a method for varying an engine displacement, the method comprising: timing of an upper intake valve in an upper non-combustion chamber of an engine block of said combustion engine; and timing of the upper exhaust valve in the upper non-combustion chamber and modifying at least one of fixing the timing of main valves in the main combustion cylinders of said engine block; Including, the main combustion cylinder is in gaseous communication with the upper non-combustion chamber; The varying of at least one of the upper intake valve timing and the upper exhaust valve timing is performed independently of one another.

27. Varying the combustion engine displacement includes operating the combustion engine in a full engine displacement mode and a partial engine displacement mode; In the full engine displacement mode, the combustion engine operates at a maximum displacement of the combustion engine; 27. The method of claim 26, wherein in the partial engine displacement mode, the combustion engine operates at less than a maximum displacement of the combustion engine.

28. varying the displacement of the combustion engine includes operating the combustion engine in a blowback mode; 28. The method of claim 26 or 27, wherein in the blowback mode, the upper intake valve is further configured to transfer exhaust gases to an intake manifold.

29. Varying the displacement of the combustion engine includes operating the combustion engine in an Otto cycle mode and an Atkinson cycle mode; In the Otto cycle mode, the combustion engine operates in a manner such that the piston compression stroke is equal to the piston expansion stroke; A method according to any one of claims 26 to 28, wherein in the Atkinson cycle mode the combustion engine has a piston compression stroke that is shorter than the piston expansion stroke.

30. timing of a plurality of upper intake valves in the upper non-combustion chamber; and timing a plurality of upper exhaust valves in the upper non-combustion chamber; The method of any one of claims 26 to 29, further comprising modifying at least one of:

31. 1. A non-transitory computer-readable medium having executable instructions stored thereon for execution by a processor to perform a method for operating a combustion engine in full displacement mode, the method comprising: fixing an upper intake valve at neutral timing, the upper intake valve being at neutral timing in an upper non-combustion chamber of an engine block of the combustion engine; Fixing an upper exhaust valve at the neutral timing, the upper exhaust valve being located within the upper non-combustion chamber; fixing the timing of main valves in the main combustion cylinders of said engine block; Including, The neutral timing of the upper intake valve and the upper exhaust valve overlaps with the timing of the main valve, and the method comprises: Fixing a valve opening period of the upper intake valve to be longer than a valve opening period of the main valve; a valve opening period of the upper exhaust valve is fixed to be longer than the valve opening period of the main valve; Including, During the exhaust stroke of a previous cycle of the combustion engine and after a piston of the combustion engine reaches a bottom dead center (BDC) position, the main valve opens, the upper exhaust valve opens, and the piston forces exhaust gases into the upper non-combustion chamber and subsequently into an exhaust manifold of the combustion engine; during the latter part of the exhaust stroke of the previous cycle, the upper intake valve opens and intake air pushes the exhaust gases from the upper non-combustion chamber through the upper exhaust valve and then into the exhaust manifold of the combustion engine; During the intake stroke of the next cycle of the combustion engine, the upper exhaust valve closes, the main valve opens, and the piston draws the intake air into the main combustion cylinder; During the compression stroke of the next cycle, the intake air is compressed in the main combustion cylinder and is ready for combustion; During the power stroke of the next cycle, the upper intake valve closes, the upper exhaust valve closes, the main valve closes, and combustion pushes the piston, rotating the crankshaft of the combustion engine.

32. 1. A non-transitory computer-readable medium having executable instructions stored thereon for execution by a processor to perform a method for operating a combustion engine in partial displacement mode, the method comprising: fixing an upper intake valve at neutral timing, the upper intake valve being in an upper non-combustion chamber of an engine block of the combustion engine; fixing an upper exhaust valve at an advanced timing, the upper exhaust valve being located within the upper non-combustion chamber; fixing the timing of main valves in the main combustion cylinders of said engine block; Including, the neutral timing of the upper intake valve overlaps with the timing of the main valve; the advance timing of the upper exhaust valve causes the upper exhaust valve to open and close before the main valve opens and closes; the advanced timing of the upper exhaust valve reduces timing overlap with the main valve during the exhaust stroke; During an exhaust stroke of a previous cycle of the combustion engine, the upper exhaust valve opens before the piston reaches a bottom dead center (BDC) position, and the main valve opens after the piston reaches the BDC position, causing the piston to push exhaust gases from the main combustion cylinder into the upper non-combustion chamber and then into an exhaust manifold of the combustion engine; During the latter part of the exhaust stroke of the previous cycle, the upper exhaust valve and the upper intake valve are closed, the main valve is open, and the piston forces exhaust gases into the upper non-combustion chamber; During the intake stroke of the next cycle of the combustion engine, the upper intake valve opens before the piston reaches a top dead center (TDC) position and before the start of the intake stroke, the upper exhaust valve closes, and the main valve opens at the start of the intake stroke, causing the piston to draw exhaust gases and subsequently intake air from the upper non-combustion chamber into the main combustion cylinder; During the compression stroke of the next cycle, the upper intake valve, the upper exhaust valve, and the main valve close, and the intake air is compressed together with the exhaust gas in the main combustion cylinder, ready for combustion; During the power stroke of the next cycle, the upper intake valve, the upper exhaust valve, and the main valve close, and combustion pushes the piston, rotating the crankshaft of the combustion engine.

33. 1. A non-transitory computer-readable medium having executable instructions stored thereon for execution by a processor for performing a method for operating a combustion engine in a blowback mode, the method comprising: fixing an upper intake valve at neutral timing, the upper intake valve being in an upper non-combustion chamber of an engine block of the combustion engine; fixing an upper exhaust valve at an advanced timing, the upper exhaust valve being located within the upper non-combustion chamber; fixing the timing of a main valve in a main combustion cylinder of said combustion engine; Including, the upper exhaust valve opens before a bottom dead center (BDC) position of a piston of the combustion engine; the neutral timing of the upper intake valve overlaps with the timing of the main valve; the valve opening period of the upper intake valve is longer than the valve opening period of the main valve; During the exhaust stroke of the previous cycle of the combustion engine, the piston pushes exhaust gases into the upper non-combustion chamber and out to the exhaust manifold; during the latter part of the exhaust stroke of the previous cycle, the upper exhaust valve closes and the upper intake valve opens, allowing exhaust gases to flow from the main combustion cylinder into the upper non-combustion chamber and then into an intake manifold of the combustion engine, thereby causing the intake manifold to act as a reservoir for the exhaust gases and intake air for the next cycle; During the intake stroke of the next cycle, the piston draws the exhaust gas and the intake air from the intake manifold, through the upper non-combustion chamber, and into the main combustion cylinder; During the compression stroke of the next cycle, the upper exhaust valve, the upper intake valve, and the main valve close, and the intake air is compressed together with the exhaust gas in the main combustion cylinder, ready for combustion; During the power stroke of the next cycle, the upper exhaust valve, the upper intake valve, and the main valve close, and combustion pushes the piston, rotating the crankshaft of the combustion engine.

34. 1. A non-transitory computer-readable medium having executable instructions stored thereon for execution by a processor for performing a method for operating a combustion engine in an Atkinson cycle mode, the method comprising: fixing an upper intake valve at an advanced timing, the upper intake valve being in an upper non-combustion chamber of an engine block of the combustion engine; fixing an upper exhaust valve at a neutral timing, the upper exhaust valve being within the upper non-combustion chamber; locking a main valve at neutral timing, said main valve being in a main combustion cylinder of said engine block; Including, the neutral timing of the upper exhaust valve allows exhaust gases to flow completely from the main combustion cylinder into the upper non-combustion chamber through the main valve; the advance timing of the upper intake valve allows the upper intake valve to open during an exhaust cycle of the combustion engine; the overlap of the upper exhaust valve and the upper intake valve simultaneously opening allows exhaust gases to be drawn into an exhaust manifold of the combustion engine through the upper intake valve, the upper non-combustion chamber, and the upper exhaust valve, whereby the intake gases displace exhaust gases in the upper non-combustion chamber, whereby the exhaust gases are exhausted from the combustion engine through the upper exhaust valve; A medium in which the early closing of the upper intake valve during the intake stroke of the combustion engine reduces the amount of gas entering the main combustion cylinder, causing the compression stroke of the combustion engine to be shorter than the expansion stroke.

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