Multi-joint crankshaft with combined eccentric shaft and camshaft drive for internal combustion engines

Abstract

An engine assembly (12) comprising the following: an engine block (13) which defines within itself a combustion chamber (17) with a cylinder bore (15); a valve arrangement which is fluidically coupled to and actuated by the combustion chamber (17) in order to selectively introduce a fluid into or evacuate it from the combustion chamber (17); a piston (16) that can be moved back and forth in the cylinder bore (15); a crankshaft (11) which is rotatably mounted on the engine block (13) and is rotatable about a first axis; a multi-point linkage that connects the piston (16) to the crankshaft (11) for driving purposes and is rotatable about a second axis that is offset from the first axis; and a control shaft (104) rotatably mounted through the engine block (13) and rotatable on a third axis offset from the first and second axes, wherein the control shaft (104) is coupled to and actuated with the multi-point linkage to selectively rotate the multi-point linkage on the second axis, and the control shaft (104) is coupled to and actuated with the valve assembly to selectively open it, wherein a phasing device (124) is mounted inside the engine block (13) and connected to the control shaft (104), wherein the multi-point linkage has a linkage body (106) with a first, a second and a third pivot joint, wherein the first pivot joint (108A) is rotatably coupled to the piston (16), the second pivot joint (108B) is rotatably coupled to the crankshaft (11) and the third pivot joint (108C) is rotatably coupled to the control shaft (104), wherein the first pivot joint (108A) is rotatably coupled to the piston (16) via a connecting rod (21), the second pivot joint (108B) is rotatably coupled to a crankpin (110) of the crankshaft (11) via a rod bearing, and the third pivot joint (108C) is rotatably coupled to the control shaft (104) via a tie rod (112), wherein the control shaft (104) includes an eccentric cam (109) which projects radially outwards from a main shaft body, and wherein a first end of the connecting rod is rotatably coupled to the third pivot joint (108C) of the multi-point linkage to rotate about a fourth axis, and a second end of the connecting rod is rotatably coupled to the eccentric cam (107) to rotate about a fifth axis which is offset from the first, second and third axes, wherein the control shaft (104) has a roller cam (109) which projects radially outwards from a main shaft body, and wherein the valve assembly has a spring-loaded valve (18) which is fluidically coupled to the combustion chamber (17) and a pushrod (116) coupled to the roller cam (109). wherein the valve assembly further comprises a pivoting rocker arm assembly (120) and a hydraulic tappet (118), wherein the pivoting rocker arm assembly (120) has a first rocker arm (121) which rests against a stem of the spring-loaded valve (18), and a second rocker arm (123) which rests against a first end of the tappet (116), and wherein the hydraulic tappet is attached to a second end of the tappet (116) and is seated on the roller cam.

Description

[0001] The present disclosure relates generally to engine assemblies. In particular, aspects of this disclosure relate to internal combustion engines with multi-section crankshafts for variable compression ratio and independent compression and expansion.

[0002] Modern production vehicles, such as the contemporary automobile, are originally equipped with a powertrain that propels the vehicle and supplies its onboard electronics. In automobiles, for example, the powertrain typically consists of a drive motor that transmits the drive torque to the vehicle's drive system (e.g., differential, axles, wheels, etc.) via an automatic or manual transmission. Historically, motor vehicles were powered by reciprocating internal combustion engines because these are readily available, relatively inexpensive, lightweight, and highly efficient. Such engines include compression-ignition (CI) diesel engines, spark-ignition (SI) gasoline engines, two-, four-, and six-stroke designs, and rotary engines, to name just a few.

[0003] Hybrid electric vehicles (HEVs) and fully electric vehicles (FEVs), on the other hand, use alternative energy sources to power the vehicle, thus minimizing or eliminating dependence on a fossil fuel-based engine for traction.

[0004] A conventional overhead valve (OCV) internal combustion engine comprises an engine block with a series of internal cylinder bores, each containing a piston that can reciprocate. Coupled to an upper surface of the engine block is a cylinder head, which interacts with the piston and cylinder bore to form a variable-volume combustion chamber. These reciprocating pistons are used to convert the pressure generated by the ignition of a fuel-air mixture in the combustion chamber into rotational forces to drive the engine's crankshaft. The cylinder head defines intake ports through which air, supplied by an intake manifold, is selectively introduced into each combustion chamber. Also defined in the cylinder head are exhaust ports through which exhaust gases and combustion byproducts are selectively routed from the combustion chambers to an exhaust manifold.The exhaust manifold, in turn, collects and bundles the exhaust gases for metered recirculation into the intake manifold, for feeding to a turbine-driven turbocharger, or for extraction from the vehicle via an exhaust system.

[0005] A conventional cylinder head houses the engine's valve train, which includes intake valves, exhaust valves, rocker arms, pushrods, and in some cases, one or more camshafts. In overhead valve (OHV) engines, the cylinder head may also house the engine's spark plugs and fuel injectors. The valve train is part of the powertrain subsystem responsible for controlling the amount of fuel-enriched air entering the engine's combustion chambers and the combustion-related exhaust gases exiting them at any given time. Engine torque and power output are varied by modulating valve lift and timing, which is achieved by driving the intake and exhaust valves, either directly or indirectly, via cams on a rotating camshaft. Different engine speeds typically require different valve timing and lift for optimal performance.In general, at low engine speeds the valves need to be opened relatively little for a shorter period, while at high engine speeds the valves need to be opened relatively much for a longer period for optimal performance.

[0006] Four-stroke internal combustion engines, as the name suggests, operate in four distinct stages or "strokes" to drive the engine's crankshaft. In one of these (first) stages, known as the "intake stroke," a metered mixture of fuel and air is introduced into each cylinder as the corresponding piston moves in a straight line from top to bottom along the length of the cylinder bore. The engine's intake valves open, creating a vacuum caused by the downward-moving piston that draws air into the combustion chamber. At the end of this cycle, a metered amount of finely atomized fuel is injected into the combustion chamber via a fuel injector. In the subsequent (second) stage, the "compression stroke," the intake and exhaust valves close as the piston moves from bottom to top, compressing the fuel-air mixture.After the compression stroke, a third stage, or "power stroke," begins. A spark plug ignites the compressed fuel and air, and the resulting explosive expansion of the gases forces the piston back to bottom dead center (BDC). In the subsequent stage—commonly known as the "exhaust stroke"—the piston, with the exhaust valves open, returns to top dead center (TDC); the moving piston expels the spent fuel-air mixture from the combustion chamber. Two crankshaft revolutions are required to complete the four strokes of a single power stroke (Otto cycle).

[0007] JP 2010 236 456 A concerns both a variable compression ratio mechanism that changes an engine compression ratio and a variable valve train that changes the valve lift characteristics of the intake valve, which are connected to a control shaft.

[0008] DE 603 ​​03 834 T2 relates to a variable stroke engine comprising a connecting rod, one end of which is connected to a piston via a piston pin, an auxiliary rod which is connected to a crankshaft via a crankpin and to the other end of the connecting rod, and a control rod, one end of which is connected to the auxiliary rod at a location that is remote from the position where the connecting rod is connected.

[0009] DE 10 2004 003 910 B4 relates to a self-igniting two-stroke internal combustion engine with at least one cylinder and associated crank mechanism, which crank mechanism comprises a reciprocating piston, a crankshaft and a lever mechanism for transmitting the forces of the reciprocating piston to the crankshaft, which is characterized in that, with a stroke-bore ratio of at least 2, the crankshaft is arranged at least partially at the axial height of the cylinder bore. DESCRIPTION

[0010] The object of the invention is to reduce the number of engine parts and to simplify manufacturing. This object is achieved by the subject matter according to claim 1. Further advantageous embodiments can be found in the dependent claims.

[0011] This paper presents variable compression ratio (VCR) and independent compression and expansion (ICE) engines, methods for manufacturing and operating such engines, and motor vehicles with an internal combustion engine featuring a multi-section crankshaft with a combined eccentric shaft and camshaft drive system. For example, a VCR / ICE engine assembly comprises a multi-section crankshaft that combines both a VCR eccentric shaft and a valve train camshaft in a single crankshaft control shaft. The crankshaft control shaft engages in a drive manner with serially aligned multi-point linkage assemblies that couple the pistons and piston rods to the crankshaft to enable a variable-length, four-stroke Atkinson cycle.A VCR / ICE phase-shifting device selectively changes the rotational displacement or phase shift of the crankshaft relative to the engine's crankshaft, thereby altering the clearance volume in the combustion chamber above the piston. In addition to facilitating VCR and ICE, the crankshaft also provides intake / exhaust valve actuation by engaging the pushrods and hydraulic rocker arms of an overhead valve train. In this engine architecture, the crankshaft timing shaft is located horizontally within the engine block alongside the cylinder bore, rather than requiring a dedicated VCR eccentric shaft in the crankcase below the crankshaft and a separate camshaft in the cylinder head above the engine block.

[0012] Integrating the valve train and VCR / ICE drive system into a common camshaft reduces the number of engine parts and simplifies manufacturing, resulting in significant time and cost savings. Furthermore, variable-compression (VCC) internal combustion engines with independent compression and expansion capabilities enable a four-stroke Atkinson cycle, where the compression stroke length can be selectively varied from the expansion stroke length under both high-load, high-speed and low-load, low-speed operating conditions to achieve improved fuel economy. Additionally, the use of a pushrod valve assembly results in smoother engine operation, extended engine life, and eliminates the need for periodic valve clearance adjustments.Further advantages include lower system complexity and reduced internal friction losses, as well as a reduction in engine size and mass with a corresponding reduction in installation space and the permissible total weight of the vehicle.

[0013] Aspects of this revelation are directed toward reciprocating internal combustion engine assemblies with VCR and ICE capabilities. For example, an engine assembly comprises an engine block which—alone (e.g., in monoblock designs) or together with a cylinder head (e.g., block-and-head designs)—defines one or more combustion chambers, each with a cylinder bore. Within each cylinder bore, a piston is slidably mounted to move back and forth along a straight centerline of the bore. A valve assembly, which may include one or more exhaust and / or intake valves with corresponding rocker arms, pushrods, and hydraulic tappets, is fluidically connected to each combustion chamber. Each intake / exhaust valve is actuated to seat and selectively open to introduce or evacuate fluid into the combustion chamber.

[0014] To continue the discussion of the example above, an engine crankshaft is rotatably mounted on the engine block, for example by main bearings, and is rotatable about a first (crank) axis to transmit the torque produced by the engine. The engine assembly also includes one or more multi-point linkages, each of which rotates on the crankshaft and drives a corresponding piston into drive engagement with the crankshaft. The multi-point linkage is rotatable about a second (joint) axis that is radially offset and substantially parallel to the axis of rotation of the crankshaft. A camshaft (or multiple camshafts for "twin-cam" configurations) is rotatably mounted on the engine block, for example by simple bearings, and is rotatable about a third (cam) axis that is horizontally and vertically offset and substantially parallel to the first and second axes. This camshaft is driven, for example by a piston, by a piston, and a piston.The camshaft is coupled to the multi-point linkage(s) via a pull rod and can be operated in such a way that the linkage(s) on the crankshaft is selectively rotated. The camshaft is also coupled to the valve assembly, e.g., via roller cams, and can be actuated in such a way that the intake / exhaust valves are selectively opened.

[0015] Further aspects of this disclosure relate to motor vehicles with internal combustion engines featuring a multi-link crankshaft with combined eccentric shaft and camshaft drive. As used herein, the terms "vehicle" and "motor vehicle" may be used interchangeably and synonymously to include any relevant vehicle platform, such as passenger cars (ICE, HEV, fuel cell, fully and partially autonomous, etc.), commercial vehicles, industrial vehicles, tracked vehicles, off-road and all-terrain vehicles (ATVs), motorcycles, agricultural equipment, trains, watercraft, aircraft, etc. The concepts presented are applicable to both automotive and non-automotive applications, including stationary power generators and pumping systems. In one example, a motor vehicle comprises a vehicle body with a passenger compartment, multiple road wheels, and other original equipment.The vehicle's powertrain comprises an internal combustion engine assembly mounted to the vehicle body, e.g. in an engine compartment, which delivers torque to selected road wheels, e.g. via a multi-speed gearbox, to propel the vehicle.

[0016] To continue the discussion of the example above, the engine assembly comprises an engine block which at least partially defines a combustion chamber with a cylinder bore; a piston is movable back and forth within the cylinder bore. A valve assembly is fluidically coupled to the combustion chamber and actuated to open selectively, thereby introducing and / or evacuating fluid from the combustion chamber. The engine also comprises a crankshaft, which is rotatably mounted on the engine block and is rotatable about a first axis. A multi-point linkage, rotatable about a second axis offset from the first, connects the piston to the crankshaft for driving purposes. The engine further comprises a camshaft, which is rotatably mounted on the engine block and is rotatable about a third axis offset from both the first and second axes.This control shaft is coupled to the multi-point linkage and can be operated to selectively rotate the multi-point linkage around the second axis. The control shaft is also coupled to the valve assembly and can be operated to selectively open it.

[0017] Aspects of this disclosure relate to methods for assembling and operating disclosed engines, powertrains, and vehicles. An example of a method for manufacturing an internal combustion engine is presented. This representative method comprises, in any order and in any combination with any of the options and features disclosed above and below, receiving an engine block defining a combustion chamber with a cylinder bore; attaching a valve assembly to the engine block, wherein the valve assembly is fluidically coupled to the combustion chamber and actuated to selectively open in order to introduce and / or evacuate a fluid into the combustion chamber; attaching a piston to the engine block to move back and forth within the cylinder bore; and attaching a crankshaft to the engine block to rotate about a first axis.Attaching a multi-point linkage to the engine block, wherein the multi-point linkage engages the piston with the crankshaft in a driving manner and rotates about a second axis offset from the first axis; attaching a camshaft to the engine block, wherein the camshaft rotates about a third axis offset from the first and second axes; coupling the camshaft to the multi-point linkage, wherein the camshaft is actuated to selectively rotate the multi-point linkage about the second axis; and coupling the camshaft to the valve assembly, wherein the camshaft is actuated to selectively open the valve assembly.

[0018] The above summary does not represent every embodiment or aspect of this disclosure. Rather, the features and advantages mentioned above, as well as other features and associated advantages of this disclosure, will be readily apparent from the following detailed description of illustrative examples and embodiments for carrying out the present disclosure, when considered in conjunction with the accompanying figures and the attached claims. Furthermore, this disclosure expressly includes all combinations and subcombinations of the elements and features described above and below. FIGURE DESCRIPTION Fig. Figure 1 is a perspective front view of a representative motor vehicle with an inserted schematic representation of a representative internal combustion engine assembly with direct injection and reciprocating piston with variable compression ratio and independent compression and expansion possibilities according to the aspects of the present disclosure. Fig. Figure 2 is a partially schematic representation of selected parts of the VCR / ICE internal combustion engine assembly. Fig. 1, which shows a multi-part crankshaft system with a crankshaft control shaft for combined control of the eccentric system and the valve train system according to aspects of the disclosed concepts.

[0019] Representative embodiments of this disclosure are shown as non-limiting examples in the drawings and are further described below. However, it should be understood that the new aspects of this disclosure are not limited to the specific forms shown in the drawings listed above. Rather, the disclosure is intended to encompass all modifications, equivalents, combinations, sub-combinations, permutations, groupings, and alternatives that fall within the scope of this disclosure, such as those covered by the attached claims. DETAILED DESCRIPTION

[0020] This disclosure can be realized in many different forms. Representative examples of the disclosure are shown in the drawings and are described in detail here, these embodiments serving as examples of the disclosed principles and not as limitations of the general aspects of the disclosure. To this end, elements and limitations described, for example, in the sections "Summary," "Introduction," "Description," "Figure Description," and "Detailed Description," but not explicitly set forth in the claims, should not be included in the claims, either individually or collectively, either by implication, by inference, or otherwise. Furthermore, the drawings discussed here may not be to scale and are provided for instructional purposes only.Therefore, the specific and relative dimensions shown in the illustrations should not be understood as limiting.

[0021] For the purposes of this detailed description, unless expressly excluded: the singular includes the plural and vice versa; the words "and" and "or" apply in both the subjunctive and disjunctive moods; the words "every" and "all" both mean "everyone and all"; and the words "including," "containing," "comprising," "with," and permutations thereof each mean "including without limitation." Furthermore, words of approximation, such as "about," "almost," "essentially," "generally," "approximately," and the like, may each be used here to mean "at, near, or almost at" or "within 0-5% of" or "within acceptable manufacturing tolerances," or any logical combination thereof. Finally, directional adjectives and adverbials, such as... B. forward, aft, inboard, outboard, starboard, port, vertical, horizontal, upward, downward, front, back, left, right, etc., used in relation to a motor vehicle, such as a forward direction of travel of a motor vehicle when the vehicle is operationally aligned on a horizontal driving surface.

[0022] Referring to the drawings, in which the same reference numbers refer to the same features in the different views, it is stated in Fig. Figure 1 shows a perspective view of a representative motor vehicle, generally designated 10, which is presented here for discussion purposes as a motor-driven, sedan-like passenger vehicle. The depicted automobile 10—here also referred to simply as the “motor vehicle” or “vehicle”—is merely an exemplary application with which novel aspects of this disclosure can be put into practice. Likewise, the implementation of the present concepts in a spark-ignition direct injection (SIDI) gasoline engine should also be understood as an exemplary application of the novel concepts disclosed herein. As such, it will be understood that features of the present disclosure can be applied to other engine configurations, implemented through alternative powertrain architectures, and used for any logically relevant type of motor vehicle.Finally, only selected components of the motor vehicle and the internal combustion engine have been shown and are further described here. Nevertheless, the vehicles and engines described below may include numerous additional and alternative features as well as other available peripheral components for carrying out the various methods and functions of this disclosure.

[0023] Fig. Figure 1 shows an example of a twin-cam V-engine assembly 12 mounted in an engine compartment 14 of the vehicle body. The engine assembly 12 shown is a four-stroke, reciprocating engine configuration that powers the vehicle 10, for example, as a direct-injection (DI) gasoline engine, including the flexible fuel vehicle (FFV) and hybrid electric vehicle (HEV) variants thereof. The engine assembly 12 can optionally operate in any assortment of selectable combustion modes, including a homogeneous charge compression ignition (HCCI) combustion mode and an adjustable stroke (SI) combustion mode. Additionally, the engine assembly 12 can operate at a stoichiometric air-fuel ratio and / or at an air-fuel ratio that is primarily stoichiometric lean. Although not explicitly shown in Fig. As shown in Figure 1, it should be appreciated that the vehicle powertrain system can be adapted to any available configuration, including front-wheel drive (FWD) layouts, rear-wheel drive (RWD) layouts, all-wheel drive (AWD) layouts, four-wheel drive (4WD) layouts, six-by-four (6X4) layouts, etc.

[0024] The engine assembly 12 is equipped with a series of reciprocating pistons 16 – typically an even number of 4, 6, 8, etc., arranged in a V or I configuration – which are slidably movable within the cylinder bores 15 of an engine block 13. The upper surface of each piston 16 interacts with the inner circumference of the corresponding cylinder 15 and a corresponding chamber surface 19 of a cylinder head 25 to define a variable-volume combustion chamber 17. Each piston 16 is actuated by a corresponding piston rod 21 and linkage (e.g., multi-point linkage 102). Fig. 2) connected to a crankpin of a rotating crankshaft 11. The crankshaft 11, in turn, converts the linear reciprocating motion of the pistons 16 into a rotary motion, which is output, for example, as a number of revolutions per minute (rpm) to a power transmission (not shown) to drive one or more impellers 22. The crankshaft 11 is shown in a crankcase 23, which is mounted below the engine block 13. Although the engine block 13, the crankcase 23, and / or the cylinder head 25 are shown as three separate parts, they can also be designed as a single, unified “monoblock” construction.

[0025] An air intake system directs the intake air via an intake manifold 29 to the cylinders 15, which then directs and distributes the air through intake ports in the cylinder head 25 into the combustion chambers 17. The engine's air intake system includes airflow channels and various electronic devices for monitoring and controlling the incoming airflow. The air intake devices can include, as a first non-limiting example, a mass airflow sensor 32 for monitoring the mass airflow (MAF) 53 and the intake air temperature (IAT) 55. A throttle valve 34 controls the airflow to the engine assembly 12 in response to an electronic control signal (ETC) 57 from a programmable engine control unit (ECU) 5. A pressure sensor 36 in the intake manifold 29 monitors, for example, the manifold absolute pressure (MAP) 59 and the barometric pressure.

[0026] An optional external flow channel (not shown) returns exhaust gases from the engine exhaust to the intake manifold 29, using an exhaust gas recirculation valve (EGR valve 38) to meter the volume of recirculated exhaust gas returned to the cylinders 15. The programmable engine control unit 5 controls the mass flow of exhaust gas to the intake manifold 29 by controlling the opening / closing of the EGR valve 38 via the EGR command 61. Fig. 1 The arrows connecting the control unit 5 with the various components of the engine assembly 12 represent electronic signals or other communication exchanges through which data and / or control commands are transmitted from one component to another.

[0027] The airflow from the intake manifold 29 into the combustion chamber 17 is controlled by one or more intake valves 20. The discharge of exhaust gases from the combustion chamber 17 to an exhaust manifold 39 is controlled by one or more exhaust valves 18. These valves 18 and 20 are shown here as spring-loaded poppet valves; however, other known types of valves can also be used. The valve train system of the representative engine assembly 12 is designed to allow the opening and closing of the intake and exhaust valves 18 and 20 to be controlled and adjusted. Although only a single pair of valves is shown, each cylinder 15 can be equipped with multiple pairs of intake / exhaust valves.

[0028] According to one example, the activation of the exhaust and intake engine valves 18, 20 can each be modulated by the control of exhaust and intake devices with variable camshaft timing / variable lift control (VCP / VLC). These VCP / VLC devices are electronically modulated to control an intake camshaft and an exhaust camshaft (below with reference to Fig. 2 described). The rotation of the intake and exhaust camshafts is linked to and indexed with the rotation of the crankshaft, so that the openings and closings of the intake and exhaust valves 20, 18 are linked to the positions of the crankshaft 11 and the pistons 16. The intake VCP / VLC device can variably switch and control the valve lift of the intake valve(s) 20 in response to a control signal (iVLC) 63 and variably adjust and control the phase of the intake camshaft for each cylinder 15 in response to a control signal (iVCP) 65. In the same way, the exhaust VCP / VLC device can variably switch and control the valve lift of the exhaust valve(s) 18 in response to a control signal (eVLC) 67 and variably adjust and control the phase position of the exhaust camshaft for each cylinder 15 in response to a control signal (eVCP) 69.The VCP / VLC devices can be actuated using an electro-hydraulic, hydraulic, electromechanical or electrical control force in response to the respective control signals eVLC, eVCP, iVLC and iVCP.

[0029] With further reference to the representative configuration of Fig. 1 The engine assembly 12 uses a direct injection fuel injection subsystem with multiple electronic high-pressure fuel injectors 28 that inject fuel pulses directly into the combustion chambers 17. As shown, each cylinder 15 is equipped with one or more injectors 28 that are activated in response to an injector pulse width command (INJ_PW) 75 from the ECU 5. These injectors 28 are supplied with pressurized fuel via a fuel distribution system. One, more, or all of the fuel injectors 28, when activated, can be operated to deliver multiple fuel pulses—a sequence of first, second, third, etc. The engine assembly 12 uses a compression ignition method (for diesel engine architectures) or a spark ignition method (for gasoline engine architectures), in which the fuel combustion initiating energy, such as...Increased temperatures in the chamber, ignited by compressed air or a sudden electrical discharge provided via a spark plug 26 in response to a spark command (IGN) 71, ignite the cylinder charges in each of the combustion chambers 17. In some applications, the fuel injectors 28 can take the form of an electronically controlled common-rail fuel injector architecture, operating, for example, with a fuel rail pressure of 2000 bar and a normally switched-off solenoid-controlled operating mode.

[0030] The engine assembly 12 is equipped with various sensor devices for monitoring engine operation, including a crankshaft position sensor 42 with an output indicating the crankshaft's rotational position, e.g., a crankshaft angle and / or speed (RPM) signal 43. A temperature sensor 44 monitors, e.g., one or more engine-related temperatures (e.g., coolant temperature, fuel temperature, etc.) and outputs a corresponding signal 45. An in-cylinder combustion sensor 30 monitors combustion-related variables, such as in-cylinder combustion pressure, charge temperature, fuel mass, air-fuel ratio, etc., and outputs a corresponding signal 31. An exhaust gas sensor 40 monitors one or more exhaust gas-related variables, e.g., the actual air-fuel ratio (AFR), the proportion of gas burned, etc., and outputs a corresponding signal 73.

[0031] The combustion pressure and crankshaft speed can be monitored by the ECU 5, for example, to determine the combustion timing, i.e., the point in time of the combustion pressure relative to the crankshaft angle 11 for each cylinder 15 for each combustion cycle. It should be understood that the combustion timing can also be determined by other methods. The combustion pressure can be monitored by the ECU 5 to determine a mean effective pressure (IMEP) for each cylinder 15 for each combustion cycle. The engine assembly 12 and the ECU 5 cooperatively monitor and determine the IMEP states for each of the engine cylinders 15 during each cylinder ignition event. Alternatively, other sensor systems can be used to monitor the states of other combustion parameters within the scope of the disclosure, e.g., ion-sensor ignition systems, EGR rates, and non-intrusive cylinder pressure sensors.

[0032] In Fig. Figure 2 shows a representative multi-link crankshaft system 100 with a common camshaft for the combined control of the eccentric system and the valve train system to enable the VCR / ICE operation of the engine assembly 12. The multi-link crankshaft system 100 is shown in Fig. 2 is represented by a multi-point linkage assembly 102 and a crankshaft control shaft 104. Each multi-point linkage assembly 102 is in drive connection with the crankshaft 11 via one of the pistons 16. The multi-point coupling assembly 102 comprises a triangular linkage body 106, which can be machined, cast, or formed as a single, unified assembly. The linkage body 106, which is housed in the engine block 13 and / or the crankcase 23, is rotatably mounted on a corresponding crankpin 110 of the crankshaft 11.

[0033] In this arrangement, the crankshaft 11 is rotatable about a first (crank) axis A1, which extends longitudinally through the radial center of the crankshaft 11. The linkage body 106, on the other hand, is rotatable about a second (linkage) axis A2, which extends through the center of the crankpin 110 and is radially offset / spaced from the first axis A1, but essentially parallel to it. Within the engine block 13, laterally adjacent to the cylinder bore 15, is a crankshaft control shaft 104, which rotates about a third (control) axis A3, which extends longitudinally through the radial center of the main body 105 of the control shaft 104. The third axis A3 of the control shaft 104 is horizontally and vertically offset / spaced from the first and second axes A1 and A2 of the crankshaft 11 and the linkage body 106, respectively, but essentially parallel to them.

[0034] At the three corners of the triangular linkage body 106 are discrete coupling bushings, namely three swivel joints 108A, 108B and 108C for connection to the crankshaft 11, the piston 16 and the control shaft 104. As in Fig. As can be seen best in Figure 2, the first pivot joint 108A rotatably couples the linkage body 106 to the piston 16 via a connecting rod 21. The rotatable coupling of the connecting rod 21 to the linkage body 106 and the piston 16 can be achieved by any suitable means, including piston pins, plain bearings, roller bearings, bushings, etc. Similarly, the second pivot joint 108B rotatably couples the linkage body 106 to the crankpin 110 of the crankshaft 11, e.g., via a connecting rod bearing (a "control joint"). Finally, the third pivot joint 108C rotatably couples the linkage body 106 to the crankshaft control shaft 104 via a tie rod 112. The rotatable coupling of the tie rod 112 to the linkage body 106 and the control shaft 104 can be achieved by any suitable means, including piston pins, plain bearings, roller bearings, bushings, etc. B. can be achieved by any of the techniques described above in relation to the piston rod 21.

[0035] The crankshaft control shaft 104 from Fig. 2 is rotatably mounted on the engine block 13, similar to the crankshaft 11; however, the camshaft 104 is located within the cylinder housing section of the block 13, above the crankshaft 11 and the crankcase 23. According to the illustrated example, the first and second axes A1 and A2 are located below the cylinder bore 15 and the piston 16, respectively, while the third axis A3 is laterally offset from the cylinder bore 15 and is located closest to the cylinder head 25 of the three axes A1-A3. The crankshaft camshaft 104 generally consists of an elongated and cylindrical main shaft body 105 with a series of longitudinally spaced eccentric cams 107 (e.g., one cam per piston) projecting radially outward from the body 105. Furthermore, a series of longitudinally spaced roller cams 109 (e.g. one cam per valve or pair of valves) project radially outwards from the body 105.The circular cams 107 and the elongated cams 109 are formed integrally with the main shaft body 105 or rigidly connected to it in order to rotate together with it.

[0036] During engine operation, the crankshaft control shaft 104 selectively rotates the linkage body 106 of the multi-point linkage assembly 102 on the crankshaft 11 and simultaneously lifts the engine valve 18, 20 out of the combustion chamber in accordance with the rotating crankshaft 11 and reinstalls it. With further reference to Fig. 2 A first (lower) end of each tie rod 112 is rotatably coupled to the third pivot joint 108C of one of the linkage bodies 106, such that the tie rod 112 rotates about a fourth (lower) connecting axis A4. A second (upper) end of each tie rod 112, on the other hand, is rotatably coupled to a corresponding eccentric 107 to rotate about a fifth (upper) axis A5, which is radially outwardly spaced from the third axis A3. Both the fourth and the fifth axes A4, A5 are offset relative to the axes of rotation A1-A3 of the crankshaft 11, the linkage body 106, and the camshaft 104.

[0037] Similar to the drawbar 112, a first (lower) end of each piston rod 21 is rotatably coupled to the first pivot joint 108A of one of the linkage bodies 106, so that the piston rod 21 rotates about a sixth (lower rod) axis A6. A second (upper) end of each piston connecting rod 21, on the other hand, is rotatably coupled to a corresponding piston 16 to rotate about a seventh (upper rod) axis A7. Both the sixth and seventh axes A6, A7 are offset relative to the axes of rotation A1-A3 of the crankshaft 11, the linkage body 106, and the camshaft 104. As in Fig. As can be seen best in Figure 2, the piston 16 moves in a straight line up and down along a central axis A8 of the cylinder bore 16; this central axis A8 is laterally offset to the first and third axes A1, A3 and therefore does not intersect them.

[0038] In this arrangement, the rotation of the control shaft 104 in a first direction (e.g. clockwise) leads to Fig. 2) to a rotation of the eccentric 107, which causes a linear reciprocating (up and down) movement of the tie rod 112. The reciprocating movement of the tie rod 112 causes the linkage body 106 to rotate back and forth on the crankpin 110 of the crankshaft 11. The rotation of the linkage body 106 on the crankshaft 11 simultaneously changes the radial distance between the piston 16 and the crankpin 110. The change in the distance between the piston 16 and the crankpin 110 simultaneously varies the stroke length of the piston 16 during the rotation of the crankshaft 11.

[0039] Together with the selective control of the piston stroke length, the crankshaft control shaft 104 also controls the operation of one or more valve assemblies 114 to control the fluid supply and / or discharge to the combustion chamber. A non-restrictive example of a "pushrod-type" valve arrangement 114 is shown in Fig. 2 is represented by a spring-loaded poppet valve 18, 20, a pushrod 116, a cam tappet 118, and a rocker arm assembly 120. The rocker arm assembly 120 is pivotally mounted in the engine block 13 or in the cylinder head 25 and can assume any suitable form, e.g., rocker arm with guide plate, rocker arm with bolt, rocker arm with slide, etc. A first (left) rocker arm 121 of the pivotally mounted rocker arms 120 sits on the distal tip of the valve stem 18, 20. The cam tappet 118, which can be designed as a hydraulic lash adjuster, a mechanical tappet, or a roller tappet, is attached to a first (lower) end of the pushrod 116 and bears against one of the roller cams 109 of the cam shaft 104. A second (upper) end of the pushrod 116 rests against a second (right) rocker arm 123 and is optionally fixedly connected to it.

[0040] The rotation of the crankshaft control shaft 104 about the central control axis A3 causes the roller cam 109 to rotate, with a cam center A9 that is radially offset from the main body 105 and rotates around it. The rotation of the roller cam 109 converts the rotary motion of the control shaft 104 into a reciprocating (up and down) linear motion of the pushrod 116. Each time the pushrod 116 moves away from the control shaft 104 (in Fig. 2 upwards), pushes the pushrod 116 against the rocker arm 123. This causes the rocker arm assembly 120 to pivot until the rocker arm 121 presses on the valve 18, 20, causing the valve 18, 20 to lift and allowing air / exhaust gas to enter / expire in the combustion chamber.

[0041] The rotation of the crankshaft control shaft 104 can be enabled by an indexed coupling of the control shaft 104 with the crankshaft 11. In Fig.Figure 2 shows a representative timing shaft drive system as a belt drive system 122, which drives the crankshaft 11 to the timing shaft 104 such that a rotation of the crankshaft 11 causes a rotation of the timing shaft 104 that is in phase or out of phase. At least in some applications, the crankshaft timing shaft 104 can rotate at half the crankshaft speed to allow eccentric shaft and camshaft drive operations via a single timing shaft 104. It should be acknowledged that other mechanical drive systems can be used in addition to or as an alternative to belt drive systems, including gear drive systems, chain drive systems, roller drive systems, etc. A phasing device 124 is mounted inside the engine block 13 and connected to the timing shaft 104.The phasing device 124 selectively changes the rotational speed of the control shaft 104 relative to the crankshaft 11 in order to change the stroke length of the piston 16. The phasing device 124 can be configured in any logically suitable configuration, including a motor-driven geared phaser or a hydraulically controlled vane phaser.

Claims

[1] An engine assembly (12) comprising the following: an engine block (13) which defines within itself a combustion chamber (17) with a cylinder bore (15); a valve arrangement which is fluidically coupled to and actuated by the combustion chamber (17) in order to selectively introduce a fluid into or evacuate it from the combustion chamber (17); a piston (16) that can be moved back and forth in the cylinder bore (15); a crankshaft (11) which is rotatably mounted on the engine block (13) and is rotatable about a first axis; a multi-point linkage that connects the piston (16) to the crankshaft (11) for driving purposes and is rotatable about a second axis that is offset from the first axis; and a control shaft (104) rotatably mounted through the engine block (13) and rotatable on a third axis offset from the first and second axes, wherein the control shaft (104) is coupled to and actuated with the multi-point linkage to selectively rotate the multi-point linkage on the second axis, and the control shaft (104) is coupled to and actuated with the valve assembly to selectively open it, wherein a phasing device (124) is mounted inside the engine block (13) and connected to the control shaft (104), wherein the multi-point linkage has a linkage body (106) with a first, a second and a third pivot joint, wherein the first pivot joint (108A) is rotatably coupled to the piston (16), the second pivot joint (108B) is rotatably coupled to the crankshaft (11) and the third pivot joint (108C) is rotatably coupled to the control shaft (104), wherein the first pivot joint (108A) is rotatably coupled to the piston (16) via a connecting rod (21), the second pivot joint (108B) is rotatably coupled to a crankpin (110) of the crankshaft (11) via a rod bearing, and the third pivot joint (108C) is rotatably coupled to the control shaft (104) via a tie rod (112), wherein the control shaft (104) includes an eccentric cam (109) which projects radially outwards from a main shaft body, and wherein a first end of the connecting rod is rotatably coupled to the third pivot joint (108C) of the multi-point linkage to rotate about a fourth axis, and a second end of the connecting rod is rotatably coupled to the eccentric cam (107) to rotate about a fifth axis which is offset from the first, second and third axes, wherein the control shaft (104) has a roller cam (109) which projects radially outwards from a main shaft body, and wherein the valve assembly has a spring-loaded valve (18) which is fluidically coupled to the combustion chamber (17) and a pushrod (116) coupled to the roller cam (109). wherein the valve assembly further comprises a pivoting rocker arm assembly (120) and a hydraulic tappet (118), wherein the pivoting rocker arm assembly (120) has a first rocker arm (121) which rests against a stem of the spring-loaded valve (18), and a second rocker arm (123) which rests against a first end of the tappet (116), and wherein the hydraulic tappet is attached to a second end of the tappet (116) and is seated on the roller cam. [2] The engine assembly (12) according to claim 1, which further comprises a cylinder head attached to the engine block (13), wherein the cylinder head (25) together with the cylinder bore (15) defines the combustion chamber (17), wherein the first, second and third axes are parallel to each other and the third axis is arranged closest to the cylinder head (25). [3] The engine assembly (12) according to claim 1, wherein the piston (16) moves back and forth in a straight line along a central axis of the cylinder bore (15), the central axis being offset from the first and third axes and not intersecting them.

Images