CN118119765A

CN118119765A - Rocker arm system with cylinder deactivation and selective valve lift capability

Info

Publication number: CN118119765A
Application number: CN202280059452.XA
Authority: CN
Inventors: G·J·米彻姆; A·C·塞西尔; D·M·巴恩斯; S·R·巴尔达科于; N·P·哈索尔
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2021-09-01
Filing date: 2022-09-01
Publication date: 2024-05-31
Also published as: KR20240051244A; GB202403982D0; GB2625019A; WO2023034896A1; EP4396448A1

Abstract

An internal combustion engine system includes an engine having a plurality of pistons received in respective ones of a plurality of cylinders. A valvetrain is provided for opening and closing intake and exhaust valves of a cylinder during nominal engine operation. The valvetrain is also configured for cylinder deactivation and provides one or more selected lift profiles for opening and closing the intake valve and/or the exhaust valve.

Description

Rocker arm system with cylinder deactivation and selective valve lift capability

Cross Reference to Related Applications

The present application claims the benefit of the filing date of U.S. provisional application serial No.63/239539, filed on 1 at 9/2021, which is incorporated herein by reference.

Background

The present invention relates to internal combustion engine systems, and more particularly, but not exclusively, to a valvetrain for an internal combustion engine including a rocker arm system having cylinder deactivation and selective valve lift capabilities.

Cylinder deactivation at low engine loads may be achieved by keeping intake and exhaust valves of a portion of the engine cylinders closed during certain operating conditions to conserve fuel and operate with increased efficiency. Cylinder deactivation typically requires switching the cam profile operating on the deactivated cylinder from a nominal profile to a zero profile. Compression release braking may be achieved with a cam profile that opens the exhaust valve for braking lift during the corresponding crank angle providing compression release from the cylinder. Accordingly, there is a continuing need in the art for further contributions.

Disclosure of Invention

In an embodiment of the present application, a rocker arm system for an internal combustion engine is disclosed. The rocker arm system includes at least one input rocker arm lever rotatable about an engine component in response to movement received from at least one camshaft lobe of a camshaft. The rocker arm system further comprises at least one output rocker arm lever rotatable about an engine component. The at least one output rocker arm lever is configured to control opening and closing of at least one exhaust valve or at least one intake valve associated with a cylinder of the internal combustion engine. The rocker arm system further includes at least one valve lift switch operable to connect the at least one input rocker arm lever and the at least one output rocker arm lever to each other to transfer motion from the at least one camshaft lobe to the at least one exhaust valve or the at least one intake valve and disconnect the at least one input rocker arm lever and the at least one output rocker arm lever from each other. The rocker arm system further comprises at least one additional input rocker arm lever or output rocker arm lever connectable to the at least one output rocker arm lever with at least one valve lift switch.

In another embodiment, a rocker arm system for an internal combustion engine is disclosed. The rocker arm system includes a first input rocker arm lever rotatable about the engine component in response to movement received from a first camshaft lobe of the camshaft and a second input rocker arm lever rotatable about the engine component in response to movement received from a second camshaft lobe of the camshaft. The rocker arm system includes at least one output rocker arm lever rotatable about an engine component, and the at least one output rocker arm lever is configured to control opening and closing of at least one exhaust valve or at least one intake valve associated with a cylinder of the internal combustion engine. The rocker arm system includes a first valve lift switch and a second valve lift switch. The first valve lift switch is operable to connect the first input rocker arm lever to the at least one output rocker arm lever to transfer motion from the first camshaft lobe to the at least one exhaust valve or the at least one intake valve. The second valve lift switch is operable to connect the second input rocker arm lever to the at least one output rocker arm lever to transfer motion from the second camshaft lobe to the at least one exhaust valve or the at least one intake valve. The first and second valve lift switches are operable to disconnect the respective first and second input rocker arm levers from the at least one output rocker arm lever such that movement from the first and second camshaft lobes is not transferred to the at least one output rocker arm lever.

This summary is provided to introduce a selection of concepts that are further described below in the exemplary embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the claimed subject matter WO 2023/034896A1

Scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and drawings.

Drawings

FIG. 1 is a schematic diagram of one embodiment of an internal combustion engine system having a valvetrain that provides alternative valve lift and cylinder deactivation capability for at least one cylinder.

FIG. 2 is a diagrammatic and schematic illustration of one embodiment of a cylinder of the internal combustion engine system of FIG. 1 and a schematic illustration of a valve actuation mechanism.

FIG. 3 is a graphical representation of exemplary lift profiles for intake and exhaust valves of cylinders of the internal combustion engine system of FIG. 1 during a standard operating mode and an exemplary braking operating mode.

Fig. 4 is a perspective view showing a valve actuation system of a cylinder and intake and exhaust valves of the internal combustion engine system of fig. 1.

FIG. 5 is an elevation view of the valve actuation system of FIG. 4 and the intake and exhaust valves.

FIG. 6 is a perspective view of one embodiment of a rocker arm system of the valve actuation system of FIG. 4.

Fig. 7 is a plan view of the rocker arm system of fig. 6.

Fig. 8 is an elevation view of the rocker arm system of fig. 6.

Fig. 9-11 are cross-sectional views of the rocker arm system of fig. 6, showing a standard lift mode of operation, a cylinder deactivation mode of operation, and an auxiliary lift mode of operation, respectively.

Fig. 12 is an elevation view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 13 is a plan view of the rocker arm system of fig. 12.

Fig. 14-16 are cross-sectional views of the rocker arm system of fig. 12, showing a standard lift mode of operation, a cylinder deactivation mode of operation, and a brake mode of operation, respectively.

Fig. 17 to 18 are sectional views illustrating an assembling method for the rocker arm system of fig. 12.

Fig. 19 is a perspective view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 20-22 are cross-sectional views of the rocker arm system of fig. 19, showing a standard lift mode of operation, a cylinder deactivation mode of operation, and a brake mode of operation, respectively.

FIG. 23 is another cross-sectional view of the rocker arm system of FIG. 19, showing a detent pin.

FIG. 24 is a perspective view of the rocker arm system of FIG. 23, showing the detent pin.

Fig. 25 is a perspective view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 26 is a plan view of the rocker arm system of fig. 25.

Fig. 27 is an elevation view of the rocker arm system of fig. 25.

Fig. 28 is a cross-sectional view of the rocker arm system of fig. 25.

Fig. 29 is a perspective view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 30 is a cross-sectional view of the rocker arm system of fig. 29.

Fig. 31 is a plan view of another embodiment of an intake side rocker arm system and an exhaust side rocker arm system for two cylinders of the internal combustion engine of fig. 1.

Fig. 32 is a cross-sectional view of the exhaust side rocker arm system of fig. 31.

Fig. 33 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 35 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 36 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 37 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 38 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 39 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 40 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Fig. 41 is a plan view of another embodiment of a rocker arm system for a cylinder of the internal combustion engine of fig. 1.

Detailed Description

While this invention may take many different forms, for the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring to fig. 1-41, embodiments of the present application include a unique system that uses one or more of the following to operate one or more cylinders 14 of an internal combustion engine 12: cylinder deactivation for low load efficiency improvement, standard or nominal lift for intake and/or exhaust valves of cylinders 14, and selective lift for one or more of cylinders 14 to provide, for example, compression release braking or swirl in the corresponding cylinders 14. Other embodiments include systems associated with an internal combustion engine system 10 having a valvetrain configured such that one or more cylinders 14 may operate at nominal exhaust and intake valve lift, cylinder deactivation, and/or selective intake and/or exhaust valve lift that varies from its standard lift in terms of lift height and/or lift timing.

In embodiments, according to embodiments of the present disclosure, rocker arm systems 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 for an internal combustion engine 12 are disclosed herein. The rocker arm system 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 includes: at least one input rocker arm lever 104、106、108、304、306、308、504、506、508、706、806、808、904、906、994、996、1010、1110、1202、1310、1410、1412、1510、1512、1514、1610、1612、1710、1712, that is rotatable about the engine component 120 in response to motion received from at least one camshaft lobe 92a, 94a, 92b, 94b, 92c, 94c of the camshaft 92, 94; and at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802, capable of rotating about the engine component 120. The at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802 is configured to control the opening and closing of at least one exhaust valve 24 or at least one intake valve 22 associated with a cylinder 14 of the internal combustion engine 12. The rocker arm system 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 includes at least one valve lift switch 150, 200, 350, 400, 550, 600, 750, 850, 870, 920, 940 operable to couple at least one input rocker arm lever 104、106、108、304、306、308、504、506、508、706、806、808、904、906、994、996、1010、1110、1202、1310、1410、1412、1510、1512、1514、1610、1612、1710、1712 and at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004. 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802 are connected to each other to transfer motion from at least one camshaft lobe 92a, 94a, 92b, 94b, 92c, 94c to at least one exhaust valve 24 or at least one intake valve 22 and to transfer at least one input rocker arm lever 104、106、108、304、306、308、504、506、508、706、806、808、904、906、994、996、1010、1110、1202、1310、1410、1412、1510、1512、1514、1610、1612、1710、1712 and at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304. 1402, 1502, 1504, 1602, 1702, 1802 are disconnected from each other. The rocker arm system 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 includes at least one additional input or output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802 capable of utilizing at least one valve lift switch 150, 200, 350. 400, 550, 600, 750, 850, 870, 920, 940 are connected to at least one output rocker lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802.

According to another embodiment of the present invention, a rocker arm system 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 for an internal combustion engine 12 is disclosed. The rocker arm system 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 includes: the first input rocker arm lever 104, 304, 504, 706, 806, 904, 994, 1010, 1110, 1202, 1310, 1410, 1510, 1610, 1710 is rotatable about the engine component 120 in response to movement received from the first camshaft lobe 92a, 94a of the camshaft 92, 94; the second input rocker arm lever 106, 108, 306, 308, 506, 508, 808, 906, 996, 1412, 1512, 1514, 1612, 1712 being rotatable about the engine component 120 in response to movement received from the second camshaft lobe 92b, 94b of the camshaft 92, 94; and at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802, capable of rotating about the engine component 120. The at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802 is configured to control the opening and closing of at least one exhaust valve 24 or at least one intake valve 22 associated with a cylinder 14 of the internal combustion engine 12. The rocker arm system 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 further includes a first valve lift switch 150, 350, 550, 750, 850, 920 and a second valve lift switch 200, 400, 600, 870, 940. The first valve lift switch 150, 350, 550, 750, 850, 920 is operable to connect the first input rocker arm lever 104, 304, 504, 706, 806, 904, 994, 1010, 1110, 1202, 1310, 1410, 1510, 1610, 1710 to at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602. 1702, 1802 to transfer motion from the first camshaft lobes 92a, 94a to at least one exhaust valve 24 or at least one intake valve 22. The second valve lift switch 200, 400, 600, 870, 940 is operable to connect the second input rocker arm lever 106, 108, 306, 308, 506, 508, 808, 906, 996, 1412, 1512, 1514, 1612, 1712 to at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802, to transfer motion from the second camshaft lobes 92b, 94b to the at least one exhaust valve 24 or at least one intake valve 22. The first and second valve lift switches 150, 350, 550, 750, 850, 920, 200, 400, 600, 870, 940 are operable to couple the respective first and second input rocker arm members 104, 304, 504, 706, 806, 904, 994, 1010, 1110, 1202, 1310, 1410, 1510, 1610, 1710, 106, 108, 306, 308, 506, 508, 808, 906, 996, 1412, 1512, 1514, 1612. 1712 are disconnected from the at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002, 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802 such that movement from the first and second camshaft lobes 92a, 94a, 92b, 94b is not transferred to the at least one output rocker arm lever 102, 302, 502, 702, 704, 802, 804, 902, 992, 1002. 1004, 1102, 1302, 1304, 1402, 1502, 1504, 1602, 1702, 1802.

Referring to FIG. 1, an internal combustion engine system 10 is shown including, for example, an internal combustion engine 12. Any engine type is contemplated, including compression ignition, spark ignition, and combinations of these. The engine 12 may include a plurality of cylinders 14. Fig. 1 illustrates a plurality of cylinders 14 in an arrangement that includes six cylinders 14 in an in-line arrangement for illustrative purposes only. Any number and arrangement of cylinders suitable for use in the internal combustion engine 12 may be utilized. The number of cylinders 14 that may be used may range, for example, from two cylinders to eighteen or more cylinders. Further, the following description will sometimes refer to one of the cylinders 14. It should be appreciated that the corresponding features of the cylinders 14 described with reference to FIG. 2 and elsewhere herein may exist in all or a subset of other cylinders 14 of the engine 12, unless otherwise indicated.

As discussed herein, the internal combustion engine system 10 includes a valve actuation system having a rocker arm system, embodiments of which are discussed further below, configured to open and close intake and/or exhaust valves of an associated cylinder 14 of the engine 12. The rocker arm system includes at least one output rocker arm lever that is selectively connectable to one or more input rocker arm levers to achieve a functional mode of operation. Functional modes of operation that may be implemented by the rocker arm system of the present disclosure include, for example, nominal or standard intake and exhaust valve operation, miller cycle intake valve operation, four-stroke engine compression braking exhaust valve operation, cylinder deactivation for intake and/or exhaust valves, two-stroke engine compression braking for intake and exhaust valves, variable swirl intake valve operation, and/or dynamic skip fire.

An exemplary embodiment of the cylinder 14 is shown in fig. 2, it being understood that any suitable cylinder embodiment is contemplated herein. The cylinder 14 typically houses a piston 16, the piston 16 being operatively attached to a crankshaft 18, the crankshaft 18 being rotated by reciprocal movement of the piston 16 within a combustion chamber 28 of the cylinder 14. Within the cylinder head 20 of the cylinder 14, there is at least one intake valve 22, at least one exhaust valve 24, and in certain embodiments, a fuel injector 26, the fuel injector 26 providing fuel to a combustion chamber 28 formed by the cylinder 14 between the piston 16 and the cylinder head 20. In other embodiments, fuel may be provided to combustion chamber 28 by port injection or by injection into the intake system upstream of combustion chamber 28. Furthermore, in the following discussion, each cylinder 14 includes two intake valves 22 and two exhaust valves 24, but this is not required in all embodiments.

The term "four-stroke" means herein the subsequent four-strokes completed by the piston 16 during two separate revolutions of the crankshaft 18 of the engine—intake, compression, work and exhaust, which is a combustion cycle. The stroke begins at Top Dead Center (TDC) when the piston 16 is at the top of the cylinder head 20 of the cylinder 14, or at Bottom Dead Center (BDC) when the piston 16 has reached its lowest point in the cylinder 14.

With further reference to FIG. 3, example nominal or standard intake and exhaust valve opening and closing profiles during a combustion cycle for an intake valve (IV 1) and an exhaust valve (EV 1) are shown. During the intake stroke of IV1, piston 16 descends away from cylinder head 20 of cylinder 14 to the bottom of the cylinder (not shown), thereby reducing the pressure in combustion chamber 28 of cylinder 14. When the intake valve 22 is open, combustion charge is produced in the combustion chamber 28 by the intake of air through the intake valve 22.

Fuel from the fuel injectors 26 may be supplied by, for example, a high pressure common rail system 30 (fig. 1) connected to a fuel tank 32. Fuel from the fuel tank 32 is drawn by a fuel pump (not shown) and fed to the common rail fuel system 30. Fuel fed from the fuel pump is accumulated in the common rail fuel system 30, and the accumulated fuel is supplied to the fuel injectors 26 of each cylinder 14 through the fuel line 34. The accumulated fuel in the common rail system may be pressurized to raise and control the fuel pressure of the fuel delivered to combustion chambers 28 of each cylinder 14. However, as noted above, any type of fuel delivery system is contemplated.

During the compression stroke in the standard operating mode, the intake valve 22 and the exhaust valve 24 are closed, as shown by IV1 and EV1 in FIG. 3. The piston 16 returns toward TDC and fuel is injected into the compressed air near TDC in the main injection event, and the compressed fuel-air mixture ignites in the combustion chamber 28 after a short delay. In the case where the engine 12 is a diesel engine, this results in the combustion charge being ignited. Ignition of the air and fuel results in a rapid increase in pressure in combustion chamber 28 that is applied to piston 16 during the power stroke of piston 16 toward BDC. Combustion phasing in combustion chamber 28 is calibrated such that an increase in pressure in combustion chamber 28 pushes piston 16, thereby providing a net positive of force/work/power of piston 16.

During the exhaust stroke, the piston 16 returns toward TDC while the exhaust valve 24 is open, as shown by EV1 in FIG. 3. This action expels the combustion products of combustion of the fuel in combustion chamber 28 and drives the spent fuel-air mixture (exhaust) through exhaust valve 24. The next combustion cycle occurs using these same intake and exhaust valve opening and closing profiles unless a cylinder deactivation condition or an alternative valve lift condition is desired, as discussed further below.

Referring back to FIG. 1, intake air flows through an intake passage 36 and an intake manifold 38 before reaching the intake valve 22. The intake passage 36 may be connected to a compressor 40a of a turbocharger 40 and an intake throttle valve 42. Intake air may be cleaned by an air cleaner (not shown), compressed by a compressor 40a, and then drawn into the combustion chamber 28 through an intake throttle 42. The intake throttle 42 may be controlled to affect the flow of air into the cylinders 14.

The intake passage 36 may also be provided with an optional cooler 44 disposed downstream of the compressor 40 a. In one example, the cooler 44 may be a Charge Air Cooler (CAC). In this example, compressor 40a may increase the temperature and pressure of the intake air, while CAC 44 may increase charge density and provide more air to the cylinders. In another example, the cooler 44 may be a Low Temperature Aftercooler (LTA). The CAC 44 uses air as the cooling medium, while the LTA uses coolant as the cooling medium.

Exhaust gas flows from combustion chamber 28 into exhaust passage 46 from an exhaust manifold 48, with exhaust manifold 48 connecting cylinders 14 to exhaust passage 46. The exhaust passage 46 is connected to the turbine 40b of the turbocharger 40 and the wastegate 50, and then into the aftertreatment system 52. Exhaust gas discharged from the combustion chamber 28 drives the turbine 40b to rotate. Wastegate 50 is a device that enables a portion of the exhaust gas to bypass turbine 40b through passage 54. The wastegate 50 may include a control valve 56, which control valve 56 may be an open/close (two position) type valve, or a full authority valve that allows control of the amount of bypass flow, or anything in between. Exhaust passage 46 may further or alternatively include an exhaust throttle valve 58 for regulating the flow of exhaust through exhaust passage 46. The exhaust gas (which may be a combination of bypass flow and turbine flow) then enters aftertreatment system 52. Other embodiments contemplate variable inlet turbines, systems without turbines, and/or systems without compressors.

Optionally, a portion of the exhaust gas may be recirculated into the intake system via an EGR passage (not shown). The EGR passage may connect the exhaust passage upstream of the turbine 40b to the intake passage 36 downstream of the intake throttle valve 42. Alternatively or additionally, a low pressure EGR system (not shown) may be provided downstream of the turbine 40b and upstream of the compressor 40 a. An EGR valve may be provided for regulating EGR flow through the EGR passage. The EGR passage may also be provided with an EGR cooler and a bypass around the EGR cooler.

Aftertreatment system 52 may include one or more devices operable to treat and/or remove materials from the exhaust that may be harmful components including carbon monoxide, nitric oxide, nitrogen dioxide, hydrocarbons, and/or soot in the exhaust. In some examples, aftertreatment system 52 may include at least one of a catalytic device and a particulate filter. The catalytic device may be a Diesel Oxidation Catalyst (DOC) device, an ammonia oxidation (AMOX) catalyst device, a Selective Catalytic Reduction (SCR) device, a three-way catalyst (TWC), a Lean NOx Trap (LNT), or the like. The reduction catalyst may comprise any suitable reduction catalyst, such as a urea-selective reduction catalyst. The particulate filter may be a Diesel Particulate Filter (DPF), a split particulate filter (PFF), or the like. The PFF is used to capture particulates in a portion of the stream; in contrast, the entire exhaust volume passes through the particulate filter.

The controller 80 is configured to receive data as input from various sensors and to send command signals as output to various actuators. Some of the various sensors and actuators that may be employed are described in detail below. The controller 80 may include, for example, a processor, memory, clock, and input/output (I/O) interfaces.

The system 10 includes various sensors such as an intake manifold pressure/temperature sensor 70, an exhaust manifold pressure/temperature sensor 72, one or more aftertreatment sensors 74 (such as differential pressure sensors, temperature sensors, pressure sensors, constituent sensors), an engine sensor 76 (which may detect an air/fuel ratio of an air/fuel mixture supplied to the combustion chamber, crank angle, rotational speed of the crankshaft, etc.), and a fuel sensor 78 for detecting fuel pressure and/or other characteristics of the fuel, the common rail 38, and/or the fuel injectors 26. Any other sensor known in the art for an engine system is contemplated.

The system 10 may also include various actuators for opening and closing the intake valve 22, for opening and closing the exhaust valve 24, for injecting fuel from the fuel injector 26, for opening and closing the wastegate valve 56, for the intake throttle 42, and/or for the exhaust throttle 58. The actuators are not illustrated in fig. 1, but those skilled in the art will know how to implement the mechanisms required by each of the components to perform the intended function. Further, in one embodiment, the actuators for opening and closing the intake and exhaust valves 22, 24 are provided as part of a Valve Actuation (VA) system 90, such as schematically illustrated in fig. 2.

Referring to fig. 4-11, further details regarding one embodiment of a VA system 90 suitable for providing cylinder deactivation of one or more of the cylinders 14 and/or alternative lift profiles for intake and/or exhaust valves of one or more of the cylinders 14 in addition to the standard lift profiles discussed above under cylinder deactivation conditions are shown. Fig. 4-5 illustrate a first VA system 90a for the intake side and a second VA system 90b for the exhaust side, which may be referred to herein collectively and individually as VA systems 90. VA system 90 may be provided for operation of one or both of intake valves 22, operation of one or both of exhaust valves 24, operation of one of intake valves 22 and one of exhaust valves 24, or operation of all of intake valves 22 and exhaust valves 24. Additionally, the VA system 90a may be provided for one or more lift profiles of the intake valve 22 that are different from one or more lift profiles for the exhaust valve 24.

Specifically, the VA system 90a includes a rocker arm system 100a that is configured to engage lobes of the intake side camshaft 92 along one or more of the cylinders 14. Alternatively or additionally, the VA system 90b may include the same, similar, or different rocker arm system 100b, with the rocker arm system 100b configured to engage the lobes of the exhaust side camshaft 94 along one or more of the cylinders 14. The rocker arm systems 100a, 100b may be referred to herein, individually or collectively, as the rocker arm system 100.

In the illustrated embodiment, the camshaft 92 includes three camshaft lobes 92a, 92b, 92c that provide at least two different valve lift profiles for the intake valve 22, and the camshaft 94 includes three camshaft lobes 94a, 94b, 94c that provide at least two different valve lift profiles for the exhaust valve 94. Other embodiments contemplate only two lobes or more than three lobes on one or both of the camshafts 92, 94. In the illustrated embodiment, the three camshaft lobes of the respective camshafts may provide, for example, a nominal or standard lift profile for the associated valves 22, 24 and one or more auxiliary lift profiles for the associated valves 22, 24 that differ from the standard lift profile in terms of height and/or timing of valve lift from their respective valve seats.

With further reference to fig. 6-8, the rocker arm system 100 includes an output rocker arm lever 102, a first input rocker arm lever 104, a second input rocker arm lever 106, and a third input rocker arm lever 108, each rotatably mounted in side-by-side relationship to an engine component 120, such as a rocker shaft. The first input rocker arm lever 104 includes a first roller 110 in direct or indirect contact with the corresponding camshaft lobe 92a, 94 a. The second input rocker arm lever 106 includes a second roller 112 in direct or indirect contact with the corresponding camshaft lobe 92b, 94 b. The third input rocker arm lever 108 includes a third roller 114 in direct or indirect contact with the corresponding camshaft lobe 92c, 94 c.

As discussed further below, one or more of the input rocker arm levers 104, 106, 108 are controlled to be selectively connectable with the output rocker arm lever 102 to transfer motion from the respective camshaft lobes 92a, 94a, 92b, 94b, 92c, 94c to the connected valve in the intake valve 22 or exhaust valve 24. Additionally, the input rocker arm levers 104, 106, 108 may be controlled to selectively disconnect from the output rocker arm lever 102 such that valve lift is not provided during cylinder deactivation. The controllable connection and disconnection of the output rocker arm 102 and the input rocker arm 104, 106, and/or 108 may occur through engagement of the output rocker arm 102 to the input rocker arm 104, 106, and/or 108, through engagement of the input rocker arm 104, 106, and/or 108 to the output rocker arm 102, and combinations thereof.

The biasing mechanism 122 includes springs 124, 126, 128, with each of the springs 124, 126, 128 contacting the output rocker arm lever 102 and a respective one of the input rocker arm levers 104, 106, 108 to bias the corresponding roller 110, 112, 114 into direct or indirect contact with the respective camshaft lobe 92a, 94a, 92b, 94b, 96a, 96 c. Also illustrated are hydraulic lash adjusters 130, 132 connected to the respective arms 102a, 102b of the output rocker arm member 102 and also connected to corresponding ones of the intake valve 22 or the exhaust valve 24. The lash adjusters 130, 132 may also be mechanical lash adjusters. In the illustrated embodiment, the biasing mechanism 122 is located on the opposite side of the rocker arm system 100 from the hydraulic lash adjusters 130, 132, although such positioning is not required.

In another embodiment, an adjustment screw or like foot may be provided instead of or in addition to the lash adjusters 130, 132. Rocker arm base 134 may also be provided for mounting to cylinder head 20, but embodiments without rocker arm base 134 are also contemplated. Additionally, embodiments are contemplated without rocker shafts, where the rocker levers can be mounted about any suitable engine component 120 (such as an end pivot integrated into the cylinder head to which the rocker levers are mounted).

The rocker arm system 100 includes a first valve lift switch 150 that is controlled to selectively connect and disconnect the first input rocker arm lever 104 and the output rocker arm lever 102 from each other to transfer motion from the associated camshaft lobes 92a, 94a to the connected valves in the intake valve 22 and/or the exhaust valve 24 or to prevent motion from the associated camshaft lobes 92a, 94a from being transferred to the connected valves in the intake valve 22 and/or the exhaust valve 24. The rocker arm system 100 further includes a second valve lift switch 200 that is controlled to selectively connect and disconnect one or both of the second and third input rocker arm levers 106, 108 and the output rocker arm lever 102 from each other to transfer motion from the associated camshaft lobes 92b, 94b, 92c, 94c to the connected valves in the intake and/or exhaust valves 22, 24 or to prevent motion from the associated camshaft lobes 92b, 94b, 92c, 94c to the connected valves in the intake and/or exhaust valves 22, 24.

With further reference to fig. 9-11, the first valve lift switch 150 is received in a bore 152 extending in the output rocker arm lever 102 and from the output rocker arm lever 102 to the first input rocker arm lever 104. The first switch 150 includes a first valve lift pin assembly 154, the first valve lift pin assembly 154 including a spring biased first valve lift pin 156, the first valve lift pin 156 including a plurality of shear pin members 170, 172, 174 in abutting, end-to-end engagement. The first valve lift pin 156 is normally biased to an engaged position via springs 158a, 158b such that the first input rocker arm lever 104 is connected to the output rocker arm lever 102, as shown in fig. 9. In the engaged position, the valve lift pin 156 spans the joint 160, 162 between the rocker levers 102, 104, forming a shear interface 160a, 162a at the joint 160, 162. The engaged position of the first valve lift switch 150 is used during operating conditions where standard or nominal lift of the intake valve 22 or exhaust valve 24 is desired from the camshaft lobes 92a, 94 a.

To disconnect or decouple the rocker levers 102, 104 from each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12 into the bore 152 through the opening 166 via the hydraulic system of the engine 12 and into the space 164 at one end of the bore 152. As shown in fig. 10 and 11, the hydraulic pressure displaces the valve lift pin 156 into contact with the base 168, compressing the springs 158a, 158b. In this case, the interface between the shear pin members 170, 172 is aligned with the joint 160 and the interface between the shear pin members 172, 174 is aligned with the joint 162. This disengaged position removes the shear interfaces 160a, 162a because the first valve lift pin 156 does not have any portion spanning the joints 160, 162. As a result, rotation of the first input rocker arm lever 104 is not transferred to the output rocker arm lever 102, and the motion imparted by the camshaft lobes 92a, 94a is not transferred to the intake valve 22 or the exhaust valve 24, but rather is absorbed by the biasing spring 124. The disengaged position of the first valve lift switch 150 is used during operating conditions in which cylinder deactivation is desired and/or during alternative lift profiles from the second and third input rocker arms 106, 108 are desired from the camshaft lobes 92b, 94b, 92c, 94 c.

The second valve lift switch 200 is received in a bore 202, the bore 202 extending in the output rocker arm lever 102 and from the output rocker arm lever 102 to the second input rocker arm lever 106 and to the third input rocker arm lever 108. The second valve lift switch 200 includes a second valve lift pin assembly 204, the second valve lift pin assembly 204 including a second valve lift pin 206, the second valve lift pin 206 including a plurality of shear pin features 220, 222 in abutting, end-to-end engagement. The second valve lift pin 206 is normally biased to the disengaged position via a spring 208, as shown in fig. 9 and 10.

In the engaged position shown in fig. 11, the second input rocker arm lever 106 and the third input rocker arm lever 108 are connected to the output rocker arm lever 102. In the engaged position, the valve lift pin 206 spans the joints 210, 212 between the rocker levers 102, 106, 108, forming shear interfaces 210a, 212a at the joints 210, 212. The engaged position of the second valve lift switch 200 is used during operating conditions where an alternate lift of the intake valve 22 or the exhaust valve 24 is desired from the camshaft lobes 92b, 94b, 92c, 94c via the input rocker arm levers 106, 108. To connect or couple the rocker arm levers 102, 106, 108 to each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12, through the opening 216, into the bore 202 via the hydraulic system of the engine 12, and into the control pressure space 214 at one end of the bore 202. The hydraulic fluid pressure displaces the valve lift pin 206 into contact with the base 218, compressing the spring 208, as shown in FIG. 11.

In the disengaged condition of fig. 9 and 10, the interface between the shear pin features 220, 222 is aligned with the joint 210 and the ends of the shear pin features 222 are located within the output rocker arm bar 102 such that the shear pin features 222 do not span the joint 212. This disengaged position removes the shear interfaces 210a, 212a because no portion of the second valve lift pin 206 spans the joints 210, 212. As a result, rotation of the second and third input rocker arm levers 106, 108 is not transferred to the output rocker arm lever 102, and the motion imparted by the camshaft lobes 92b, 94b, 92c, 94c is not transferred to the intake valve 22 or the exhaust valve 24, but rather is absorbed by the biasing springs 126, 128. The disengaged position of the second valve lift switch 200 is used during operating conditions where cylinder deactivation is desired, or during operating conditions where nominal or standard lift profiles from the first input rocker arm 104 are desired from the camshaft lobes 92a, 94 a.

Fig. 12-18 illustrate another embodiment of a rocker arm system 300. The rocker arm system 300 may be similar to the rocker arm system 100 discussed above, and the following discussion is directed to additional features of the rocker arm system 300. One or more aspects or features of the rocker arm system 100 discussed above may be provided for the rocker arm system 300, and vice versa.

Referring to fig. 12-13, the rocker arm system 300 includes an output rocker arm lever 302, a first input rocker arm lever 304, a second input rocker arm lever 306, and a third input rocker arm lever 308, each of which is rotatably mountable to an engine component 120, such as a rocker arm shaft. The first input rocker arm lever 304 includes a first roller 310 for direct or indirect contact with the corresponding camshaft lobe 92a, 94 a. The second input rocker arm lever 306 includes a second roller 312 for direct or indirect contact with the corresponding camshaft lobe 92b, 94 b. The third input rocker arm lever 308 includes a third roller 314 in direct or indirect contact with the corresponding camshaft lobe 92c, 94 c.

One or more of the input rocker arm levers 304, 306, 308 may be selectively connectable with the output rocker arm lever 302 to transfer motion from the respective camshaft lobes 92a, 94a, 92b, 94b, 92c, 94c to the connected valve of the intake valve 22 or exhaust valve 24. Additionally, the input rocker arm levers 304, 306, 308 may be disconnected from the output rocker arm lever 302 such that no valve lift is provided during cylinder deactivation. The connection and disconnection of the output rocker arm 302 and the input rocker arms 304, 306, and/or 308 may occur through engagement of the output rocker arm 302 to the input rocker arm 304, 306, and/or 308, through engagement of the input rocker arm 304, 306, and/or 308 to the output rocker arm 302, and combinations thereof.

The biasing mechanism 322 includes springs 324, 326, 328, each of which springs 324, 326, 328 is in contact with a respective one of the output rocker arm lever 302 and the input rocker arm lever 304, 306, 308 to bias the corresponding roller 310, 312, 314 into direct or indirect contact with the respective camshaft lobe. The biasing mechanism 322 differs from the biasing mechanism 122 in that the spring 324 for the first input rocker lever 304 is disposed on the same side of the rocker assembly as the lash adjusters 330, 332. Lash adjusters 330, 332 (which may be mechanical or hydraulic) are connected to the respective arms 302a, 302b of the output rocker arm member 302 and to corresponding ones of the intake valve 22 or the exhaust valve 24.

The rocker arm system 300 includes a first valve lift switch 350 for selectively connecting and disconnecting the first input rocker arm lever 304 with the output rocker arm lever 302 to transfer motion from the associated camshaft lobes 92a, 94a to or to prevent motion from the associated camshaft lobes 92a, 94a from being transferred to the connected valves in the intake and/or exhaust valves 22, 24. The rocker arm system 300 further includes a second valve lift switch 400 for selectively connecting and disconnecting one or both of the second and third input rocker arm levers 306, 308 with the output rocker arm lever 302 to transfer motion from the associated camshaft lobes 92b, 94b, 92c, 94c to the connected valves in the intake and/or exhaust valves 22, 24 or to prevent motion from the associated camshaft lobes 92b, 94b, 92c, 94c to the connected valves in the intake and/or exhaust valves 22, 24.

With further reference to fig. 14-16, the first valve lift switch 350 is received in a bore 352 extending in the output rocker lever 302 and from the output rocker lever 302 to the first input rocker lever 304. The first valve lift switch 350 includes a first valve lift pin assembly 354, the first valve lift pin assembly 354 including a first valve lift pin 356, the first valve lift pin 356 including a plurality of shear pin features 370, 372 that are normally biased away from each other via a spring 358 to an engaged position such that the first input rocker arm lever 304 is connected to the output rocker arm lever 302, as shown in fig. 14. In the engaged position, the valve lift pin 356 spans the joints 360, 362 between the rocker arms 302, 304, forming shear interfaces 360a, 362a at the joints 360, 362. The engaged position of the first switch 350 is used during operating conditions where standard or nominal lift of the intake valve 22 or the exhaust valve 24 is desired from the camshaft lobes 92a, 94 a.

To disconnect or decouple the rocker levers 302, 304 from each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12 into the bore 352 through the openings 366a, 366b via the hydraulic system of the engine 12 and into the spaces 364a, 364b at opposite ends of the bore 352. The hydraulic fluid pressure displaces the shear pin members 370, 372 toward each other by the compression spring 358, as shown in fig. 15 and 16. In this case, the shear pin members 370, 372 move completely into the first input rocker arm lever 304. This disengaged position removes the shear interfaces 360a, 362a because the first valve lift pin 356 does not have any portion spanning the joints 360, 362. As a result, rotation of the first input rocker arm lever 304 is not transferred to the output rocker arm lever 302, and the motion imparted by the camshaft lobes 92a, 94a is not transferred to the intake valve 22 or the exhaust valve 24. The disengaged position of the first valve lift switch 350 is used during operating conditions where cylinder deactivation is desired, or during alternative lift profiles from the second and third input rocker arms 306, 308 are desired from the camshaft lobes 92b, 94b, 92c, 94 c.

The second valve lift switch 400 is received in a bore 402 in the output rocker arm lever 302, the second input rocker arm lever 306, and the third input rocker arm lever 308. The second valve lift switch 400 includes a second valve lift pin assembly 404, the second valve lift pin assembly 404 including a second valve lift pin 406, the second valve lift pin 406 including a plurality of shear pin features 420, 422 in the bore 402. The shear pin features 420 and 422 are normally biased toward each other via springs 408, 409 and against the central base 418 in the bore 402 to a disengaged position, as shown in fig. 14 and 15.

In the engaged position shown in fig. 16, the second input rocker arm lever 306 and the third input rocker arm lever 308 are connected to the output rocker arm lever 302. In the engaged position, the shear pin features 420, 422 of the shear pin 406 span the joints 410, 412 between the rocker levers 302, 306, 308, forming shear interfaces 410a, 412a at the joints 410, 412. The engaged position of the second valve lift switch 400 is used during operating conditions where an alternate lift of the intake valve 22 or the exhaust valve 24 is desired from the camshaft lobes 92b, 94b, 92c, 94c via the input rocker arm levers 306, 308. To connect or couple the rocker arms 302, 306, 308 to each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12 through the opening 416 into the bore 402 via the hydraulic system of the engine 12 and into the control pressure space 414 of the bore 402 between the shear pin features 420, 422. Hydraulic fluid pressure displaces the shear pin members 420, 422 away from the base 418, compressing the springs 408, 409 such that the shear pin members span the joints 410, 412, as shown in fig. 16.

In the disengaged condition, the shear pin features 420, 422 are located within the output rocker arm lever 302 such that the shear pin features 420, 422 do not span the joints 410, 412. This disengaged position removes the shear interfaces 410a, 412a because the second valve lift pin 406 does not have any portion spanning the joints 410, 412. As a result, rotation of the second and third input rocker arm levers 306, 308 is not transferred to the output rocker arm lever 302, and the motion imparted by the camshaft lobes 92b, 94b, 92c, 94c is not transferred to the intake valve 22 or the exhaust valve 24. The disengaged position of the second valve lift switch 400 is used during operating conditions where cylinder deactivation is desired, or during operating conditions where a nominal or standard lift profile from the first input rocker arm lever 304 is desired from the camshaft lobes 92a, 94 a.

Fig. 17-18 illustrate an example assembly process for assembling the output rocker arm lever 302 with the first input rocker arm lever 304. In fig. 17, shear pin features 370, 372 may be held in place via temporary assembly pins 450, 452, which temporary assembly pins 450, 452 are inserted into assembly holes 454, 456, respectively, in the output rocker arm lever 302. The assembly pins 450, 452 retain the shear pin members 370, 372 in a retracted position in the output rocker arm lever 302, with the spring 358 compressed between the shear pin members 370 and 372. Once the input rocker arm lever 304 is aligned with the output rocker arm lever 302, the assembly pins 450, 452 may be removed, allowing the shear pin features 370, 372 to spring back into place and ride over the joints 410, 412 to complete the assembly. Each shear pin part 370, 372 may be provided with a slot 458, 460, respectively, to receive a screwdriver or other tool to assist in aligning the respective shear pin part 370, 372 to receive the corresponding assembly pin 450, 452.

Fig. 19-24 illustrate another embodiment of a rocker arm system 500. The rocker arm system 500 may be similar to the rocker arm systems 100, 300 discussed above, and the following discussion is directed to additional features of the rocker arm system 500. One or more aspects or features of the rocker arm system 100, 300 discussed above may be provided for the rocker arm system 500, and vice versa.

Referring to fig. 19, a rocker arm system 500 includes an output rocker arm lever 502, a first input rocker arm lever 504, a second input rocker arm lever 506, and a third input rocker arm 508, each of which is rotatably mountable to an engine component 120 such as a rocker shaft. The first input rocker arm lever 504 includes a first roller 510 for direct or indirect contact with the corresponding camshaft lobe 92a, 94 a. The second input rocker arm lever 506 includes a second roller 512 for direct or indirect contact with the corresponding camshaft lobe 92b, 94 b. The third input rocker arm lever 508 includes a third roller 514 for direct or indirect contact with the corresponding camshaft lobe 92c, 94 c.

One or more of the input rocker arm levers 504, 506, 508 are controlled to selectively connect with the output rocker arm lever 502 to transfer motion from the respective camshaft lobes 92a, 94a, 92b, 94b, 92c, 94c to the connected valve of the intake valve 22 or exhaust valve 24. Additionally, the input rocker arm levers 504, 506, 508 may be controlled to selectively disconnect from the output rocker arm lever 502 such that valve lift is not provided during cylinder deactivation. Controlled connection and disconnection of the output rocker arm 502 and the input rocker arm 504, 506, and/or 508 may occur through engagement of the output rocker arm 502 to the input rocker arm 504, 506, and/or 508, through engagement of the input rocker arm 504, 506, and/or 508 to the output rocker arm 502, and combinations thereof.

The biasing mechanism includes: brake bias springs 524, 526, each in contact with a respective one of the input rocker arm levers 506, 508 and the output rocker arm lever 502; and a standard biasing spring 522 in contact with the input rocker arm lever 504 and the output rocker arm lever 502 to bias the corresponding rollers 510, 512, 514 into direct or indirect contact with the respective camshaft lobes. Lash adjusters 530, 532 (which may be mechanical or hydraulic) are connected to the output rocker arm lever 502 and to corresponding ones of the intake valve 22 or the exhaust valve 24.

The rocker arm system 500 includes a first valve lift switch 550 for selectively connecting and disconnecting the first input rocker arm lever 504 with the output rocker arm lever 502 to transfer motion from the associated camshaft lobes 92a, 94a to the connected valves in the intake and/or exhaust valves 22, 24 or to prevent motion from the associated camshaft lobes 92a, 94a from being transferred to the connected valves in the intake and/or exhaust valves 22, 24. The rocker arm system 500 further includes a second valve lift switch 600 for selectively connecting and disconnecting the input rocker arm levers 506, 508 with the output rocker arm lever 502 to transfer motion from the associated camshaft lobes 92b, 94b, 92c, 94c to the connected valves in the intake and/or exhaust valves 22, 24 or to prevent motion from the associated camshaft lobes 92b, 94b, 92c, 94c to the connected valves in the intake and/or exhaust valves 22, 24.

With further reference to fig. 20-22, the first valve lift switch 550 is received in a bore 552, the bore 552 extending between the output rocker arm member 502 and the first input rocker arm member 504. The first valve lift switch 550 includes a first valve lift pin assembly 554, the first valve lift pin assembly 554 including a first valve lift pin 556, the first valve lift pin 556 including a plurality of shear pin features 570, 572, 574 that are biased into contact with one another, typically via springs 558, into an engaged position against the end base 518 such that the first input rocker arm member 504 is connected to the output rocker arm member 502, as shown in fig. 20. In the engaged position, the valve lift pin 556 spans the joints 560, 562 between the rocker levers 502, 504, forming shear interfaces 560a, 562a at the joints 560, 562. The engaged position of the first switch 550 is used during operating conditions where standard or nominal lift of the intake valve 22 or the exhaust valve 24 is desired from the camshaft lobes 92a, 94 a.

To disconnect or decouple the rocker levers 502, 504 from each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12 into the bore 552 via the hydraulic system of the engine 12, into the control volume 566 at the end of the bore 552 opposite the spring 558. The hydraulic fluid pressure in the control volume 566 displaces the shear pin members 570, 572, 574 away from the open base 518 toward the opposite ends of the bore 552, compressing the spring 558, as shown in fig. 21 and 22. In this case, the end-to-end engagement of shear pin members 570, 572, 574 is moved into alignment with joints 560, 562. This aligned position removes the shear interfaces 560a, 562a because the first valve lift pin 556 does not have any portion spanning the joints 560, 562. As a result, rotation of the first input rocker arm lever 504 is not transferred to the output rocker arm lever 502, and the motion imparted by the camshaft lobes 92a, 94a is not transferred to the intake valve 22 or the exhaust valve 24. The disengaged position of the first valve lift switch 550 is used during operating conditions where cylinder deactivation is desired, or during alternative lift profiles from the second and third input rocker arms 506, 508 are desired from the camshaft lobes 92b, 94b, 92c, 94 c.

The second valve lift switch 600 is received in a bore 602 in the output rocker arm lever 502, the second input rocker arm lever 506, and the third input rocker arm lever 508. The second valve lift switch 600 includes a second valve lift pin assembly 604, the second valve lift pin assembly 604 including a second valve lift pin 606, the second valve lift pin 606 including a plurality of shear pin features 620, 622, 624 in the bore 602. The shear pin members 620, 622, 624 are normally biased into end-to-end contact with each other via the spring 608 and into a disengaged position against the end base 618 in the bore 602, as shown in fig. 20 and 21.

In the engaged position shown in fig. 22, the second input rocker arm lever 506 and the third input rocker arm lever 508 are connected to the output rocker arm lever 502. In the engaged position, the shear pin features 620, 622, 624 of the shear pin 606 span the joints 610, 612 between the rocker levers 502, 506, 508, forming shear interfaces 610a, 612a at the joints 610, 612. The engaged position of the second valve lift switch 600 is used during operating conditions where an alternate lift of the intake valve 22 or the exhaust valve 24 is desired from the camshaft lobes 92b, 94b, 92c, 94c via the input rocker arm levers 506, 508. To connect or couple the rocker levers 502, 506, 508 to each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12, through the opening 616, into the bore 602, and into the control pressure space 614 of the bore 602 at the end base 618, via the hydraulic system of the engine 12. Hydraulic fluid pressure displaces the shear pin members 620, 622, 624 away from the end base 618, compressing the spring 608 such that the shear pin members span the joints 610, 612, as shown in fig. 22.

In the disengaged state, the shear pin features 620, 622, 624 are located within the output rocker arm lever 502 and the input rocker arm levers 506, 508 such that the shear pin features 620, 622, 624 do not span the joints 610, 612. This disengaged position removes the shear interfaces 610a, 612a because the second valve lift pin 606 does not have any portion spanning the joints 610, 612. As a result, rotation of the second and third input rocker arm levers 506, 508 is not transferred to the output rocker arm lever 502, and the motion imparted by the camshaft lobes 92b, 94b, 92c, 94c is not transferred to the intake valve 22 or the exhaust valve 24. The disengaged position of the second valve lift switch 600 is used during operating conditions where cylinder deactivation is desired, or during operating conditions where a nominal or standard lift profile from the first input rocker arm lever 504 is desired from the camshaft lobes 92a, 94 a.

Referring to fig. 23-24, the rocker arm system 500 is shown with a plurality of detent pins 580 engaged to each of the input rocker arm bars 504, 506, 508. The output rocker arm lever 502 includes a stop member protrusion 582, the stop member protrusion 582 contacting the stop member 580 when the parts of the apertures 552, 602 are aligned with one another. The stop pin 580 is configured to prevent over-rotation of the output rocker arm lever 502 in the clockwise direction of fig. 23. The stop pin 580 also prevents over-rotation of the input rocker arm levers 504, 506, 508 in a counter-clockwise direction. This ensures that the portions of the bore 552 and/or the bore 602 that receive the various parts of the valve lift pins 556, 606 are aligned with one another along the base circle of the corresponding cam lobe even when the lash adjustment of the intake and/or exhaust valves 22, 24 varies. The aligned portions of the apertures 552, 602 allow for smooth actuation of the valve lift pins 556, 606 to selectively engage the input rocker arms 504, 506, 508 with the output rocker arm 502.

Referring to fig. 25-28, another embodiment of a rocker arm system 700 is shown. The rocker arm system 700 may be similar to the rocker arm systems 100, 300, 500 discussed above, and the following discussion is directed to additional features of the rocker arm system 700. One or more aspects or features of the rocker arm system 100, 300, 500 discussed above may be provided for the rocker arm system 700, and vice versa.

Referring to fig. 25-27, the rocker arm system 700 includes a first output rocker arm lever 702, a second output rocker arm lever 704, and a first input rocker arm lever 706, each of which is rotatably mountable to an engine component 120, such as a rocker shaft. A retaining ring 121 may be provided to secure the rocker shaft 702, 704, 706 to the rocker shaft 120. The second output rocker arm bar 704 includes a first roller 710 for direct or indirect contact with the corresponding camshaft lobe 92a, 94 a. The first input rocker arm lever 706 includes a second roller 712 for direct or indirect contact with the corresponding camshaft lobe 92b, 94 b. If desired, one or more additional input rocker arm members may be provided for direct or indirect contact with other camshaft lobes, if additional valve lift functionality is desired.

The second output rocker arm lever 704 may be controlled to selectively connect with the first output rocker arm lever 702 to transfer motion from the respective camshaft lobes 92a, 94a to the connected valve in the intake valve 22 or exhaust valve 24. Additionally, the second output rocker arm lever 704 and/or the input rocker arm lever 706 may be controlled to be connected to each other and disconnected from the first output rocker arm lever 702 such that alternative valve lift may be provided from the input rocker arm lever 706 to the second output rocker arm lever 704. The connection and disconnection of the output rocker bars 702, 704 and the input rocker bar 706 may occur through engagement of the first output rocker bar 702 to the rocker bars 704, 706, through engagement of the second output rocker bar 704 to the first output rocker bar 702 and to the input rocker bar 706, through engagement of the input rocker bar 706 to the second output rocker bar 704, and combinations thereof.

The biasing mechanism includes biasing springs 724, 726, with each of the biasing springs 724, 726 being in contact with a respective one of the output rocker arm lever 702 and the output rocker arm lever 704 and the input rocker arm lever 706 to bias the respective roller 710, 712 into direct or indirect contact with the respective camshaft lobe. Lash adjusters 730, 732 (which may be mechanical or hydraulic) are connected to the output rocker arms 702, 704 and to corresponding ones of the intake valves 22 or exhaust valves 24.

The rocker arm system 700 includes a valve lift switch 750, which valve lift switch 750 is controllable for selectively connecting and disconnecting the first output rocker arm lever 702 to the second output rocker arm input rocker arm 704 and simultaneously connecting the second output rocker arm lever 704 to the input rocker arm lever 706, transferring motion from the associated camshaft lobe to the connected valve in the intake valve 22 and/or exhaust valve 24 or preventing motion from the associated camshaft lobe to the connected valve in the intake valve 22 and/or exhaust valve 24. The rocker arm system 700 may also include additional valve lift switches, such as those disclosed herein, that are controlled to selectively connect and disconnect additional input rocker levers for increased functions, such as cylinder deactivation, two-stroke braking, and the like.

With further reference to fig. 28, the valve lift switch 750 is received in a bore 752, the bore 752 extending in and from the first output rocker arm 702, the second output rocker arm 704, and the input rocker arm 706. The valve lift switch 750 includes a first valve lift pin assembly 754, the first valve lift pin assembly 754 including a first valve lift pin 756 including a plurality of shear pin features 770, 772 that are normally biased by springs 758, 759 to connect the first and second output rocker arm members 702, 704 and disconnect the input rocker arm member 706, as shown in fig. 28. In the engaged position, the valve lift pin 756 spans the joint 760 between the rocker levers 702, 704, forming a shear interface 760a at the joint 760. The engaged position of the switch 750 is used during operating conditions where standard or nominal lift of the intake valve 22 or exhaust valve 24 is desired from the camshaft lobes 92a, 94 a.

To disconnect or decouple the output rocker levers 702, 704 from each other, hydraulic fluid pressure is supplied from the rocker shaft 120 of the engine 12 into the bore 752 via the hydraulic system of the engine 12, into the control volume 766 at the end of the bore 752 opposite the springs 758, 759. Hydraulic fluid pressure in the control volume 766 displaces the shear pin members 770, 772 toward opposite ends of the bore 752, compressing the springs 758, 759. In this case, the shear pin feature 770 moves away from the first input rocker lever 702 into alignment with the joint 760. This aligned position removes the shear interface 760a because no portion of the first valve lift pin 756 spans the joint 760. As a result, rotation of the second output rocker arm lever 704 is not transferred to the first output rocker arm lever 702, and the motion imparted by the camshaft lobes 92a, 94a is not transferred to the intake valve 22 or the exhaust valve 24.

Actuation of the valve lift switch 750 also simultaneously connects the input rocker arm member 706 with the second output rocker arm member 704. Displacement of shear pin feature 770 displaces shear pin feature 772 such that shear pin feature 770 spans joint 762 and shear pin feature 772 spans joint 764, creating a shear interface between rocker arms 704, 706 at joints 762, 764. This actuated position of the valve lift switch 750 is used during the following operating conditions: under this operating condition, for valves connected to the second output rocker arm 704, braking or other alternative valve lift is desired from the alternative camshaft lobes 92b, 94b, 92c, 94c via the input rocker arm lever 706. Other embodiments contemplate the use of other input rocker arms and/or valve lift switches to connect other input rocker arms and/or provide cylinder deactivation.

Referring to fig. 29-30, another embodiment of a rocker arm system 800 is shown. The rocker arm system 800 may be similar to the rocker arm systems 100, 300, 500, 700 discussed above, and the following discussion is directed to additional features of the rocker arm system 800. One or more aspects or features of the rocker arm system 100, 300, 500, 700 discussed above may be provided for the rocker arm system 800, and vice versa.

The rocker arm system 800 includes a first output rocker arm lever 802, a second output rocker arm lever 804, a first input rocker arm lever 806, and a second input rocker arm lever 808, each of which is rotatably mountable to an engine component 120, such as a rocker shaft. The first input rocker arm lever 806 includes a first roller 810 for direct or indirect contact with the corresponding camshaft lobe 92a, 94 a. The second input rocker arm lever 808 includes a second roller 812 for direct or indirect contact with the corresponding camshaft lobe 92b, 94 b. If desired, one or more additional input rocker arm members may be provided for direct or indirect contact with other camshaft lobes, if additional valve functionality is desired.

The first input rocker arm lever 806 is selectively connectable with the first and second output rocker arm levers 802, 804 to transfer motion from the respective camshaft lobes 92a, 94a to the connected valves in the intake or exhaust valves 22, 24. Additionally, a second input rocker arm lever 808 may be connected to the second output rocker arm lever 804 such that an alternative valve lift may be provided from the second input rocker arm lever 808 to the second output rocker arm lever 804. The connection and disconnection of the output rocker levers 802, 804 and the input rocker levers 806, 808 may occur through engagement of the output rocker levers to the input rocker levers, engagement of the input rocker levers to the output rocker levers, and combinations thereof.

The biasing mechanism includes biasing springs 824, 826, 828, with the biasing springs 824, 826, 828 each contacting a respective one of the output rocker arm levers 802, 804 and the input rocker arm levers 806, 808 to bias the corresponding roller 810, 812 into direct or indirect contact with the respective camshaft lobe. Lash adjusters 830, 832 (which may be mechanical or hydraulic) are connected to the output rocker arm levers 802, 804 and to corresponding ones of the intake or exhaust valves 22, 24.

The rocker arm system 800 includes a first valve lift switch 850, which first valve lift switch 850 may be controlled to selectively connect and disconnect a first output rocker arm lever 802 and a second output rocker arm input rocker arm 804 with a first input rocker arm lever 806. Similar to the valve lift switches discussed above, the first valve lift switch 850 includes a valve lift pin assembly 854, which valve lift pin assembly 854 includes a valve lift pin 856 having a plurality of shear pin features 858, 860, 862. In the engaged position, the shear pin features 860, 862 span the joints 864, 866 at the shear interfaces 864a, 866a to connect the first input rocker arm lever 806 to the output rocker arm levers 802, 804. The valve lift pins 856 may be hydraulically actuated to compress the springs 852, 853 and align the end-to-end abutments of the shear pin features 858, 860, 862 with the joints 864, 866 to decouple the first input rocker arm lever 806 from the output rocker arm levers 802, 804, such as for cylinder deactivation.

The rocker arm system 800 includes a second valve lift switch 870 to selectively connect the second input rocker arm lever 808 to the second output rocker arm lever 804 to provide an alternative valve lift profile from different cam lobes. The second valve lift switch 870 includes a valve lift pin assembly 874, the valve lift pin assembly 874 including a first pin member 876 and a second pin member 878, the first pin member 876 and the second pin member 878 being biased into the second input rocker 808, typically with springs 880, 882. Hydraulic fluid pressure is used to actuate the first and second pin members 876, 878 away from each other to span the joints 884, 886 between the second input rocker arm member 808 and the second output rocker arm member 804. The second input rocker arm lever 808 may be connected to the second output rocker arm lever 804 during, for example, exhaust braking.

Referring to fig. 31-32, a plurality of exhaust rocker arm systems 900a, 900b (collectively and individually referred to as exhaust rocker arm system 900) and intake rocker arm systems 990a, 990b (collectively and individually referred to as intake rocker arm system 990) are shown along two cylinders 14 of the engine. The intake rocker arm system 990 includes a pair of output rocker arm bars 992, with each of the pair of output rocker arm bars 992 being connected to an intake valve with a crosshead 998. The intake rocker arm system 990 also includes two input rocker arm levers 994, 996 that are selectively connected and disconnected from the respective output rocker arm levers 992 to provide a desired intake valve lift profile.

Each exhaust rocker arm system 900 includes an output rocker arm lever 902 connected to a single exhaust valve 24 for each cylinder 14. The exhaust rocker arm system 900 also includes a first input rocker arm lever 904 and a second input rocker arm lever 906 that are selectively connected and disconnected from the output rocker arm lever 902 to provide a desired valve lift.

For example, as shown in fig. 32, a first valve lift switch 920 is provided for selectively connecting and disconnecting the output rocker arm lever 902 and the first input rocker arm lever 904. Similar to the valve lift switches discussed above, the first valve lift switch 920 includes a valve lift pin assembly 924, which valve lift pin assembly 924 includes a valve lift pin 926 having a plurality of shear pin features 928, 930. In the normal engaged position, the valve lift pin 926 is biased by a spring 932 such that the shear pin feature 928 spans the joint 934 to connect the first input rocker arm lever 904 to the output rocker arm lever 902. The valve lift pins 926 may be hydraulically actuated to compress springs 932 and align end-to-end abutments of the shear pin features 928, 930 with the joint 934 to decouple the first input rocker arm lever 904 from the output rocker arm lever 902, such as for cylinder deactivation.

The exhaust rocker arm system 900 includes a second valve lift switch 940 to selectively connect the second input rocker arm lever 906 to the output rocker arm lever 902 to provide an alternative valve lift profile from different cam lobes. The second valve lift switch 940 includes a valve lift pin assembly 944 that includes a first pin member 946 and a second pin member 948, the first pin member 946 and the second pin member 948 being normally biased with a spring 952 to align the end-to-end abutments of the pin members 946, 948 with the joint 954. Hydraulic fluid pressure is used to actuate the first and second pin members 946, 948 to compress the spring 952 and cause the first pin member 946 to ride across the joint 954 between the second input rocker arm lever 906 and the output rocker arm lever 902. The second input rocker arm lever 906 may be connected to the output rocker arm lever 902 during, for example, exhaust braking.

Referring to fig. 33, another embodiment of a rocker arm system 1000 is shown. The rocker arm system 1000 includes a first output rocker arm lever 1002 and a second output rocker arm lever 1004, each of which is rotatable about an engine component 120, such as a rocker shaft. Any suitable engine component about which the rocker lever may rotate is contemplated. Each of the first output rocker arm bar 1002 and the second output rocker arm bar 1004 includes a mechanical lash adjuster 1006, 1008. In another embodiment, the lash adjusters 1006, 1008 are hydraulic lash adjusters rather than mechanical lash adjusters. The rocker arm system 1000 also includes an input rocker arm lever 1010 rotatable about the engine component 120. The input rocker arm lever 1010 is functionally associated with the first output rocker arm lever 1002 and the second output rocker arm lever 1004 and operates in two modes to impart lift profiles to the first output rocker arm lever 1002 and the second output rocker arm lever 1004. As used herein, a lift profile may also include a partial lift profile.

In the first mode, the input rocker lever 1010 operates in an activated or deactivated state. In the activated state, the input rocker arm lever 1010 engages the first output rocker arm lever 1002 and the second output rocker arm lever 1004, resulting in rotational movement of the first output rocker arm lever 1002 and the second output rocker arm lever 1004 with the cam lobes acting on the roller 1020. Alternatively, the first output rocker arm bar 1002 and the second output rocker arm bar 1004 engage the input rocker arm bar 1010. In the deactivated state, the input rocker arm lever 1010 is disengaged from the first and second output rocker arm levers 1002, 1004 and motion of the cam lobe 1020 is absorbed by lost motion devices 1012, 1014. The lost motion devices 1012, 1014 may include, for example, compressible bodies, coil springs, helical springs, wave springs, or hydraulic cylinders that can apply a reactive force. In the deactivated state of the first mode, valve motion for the connected intake and exhaust valves 22, 24 may be closed.

In the second mode, the input rocker lever 1010 operates in an activated or deactivated state. In the activated state, the input rocker arm lever 1010 engages either the first output rocker arm lever 1002 or the second output rocker arm lever 1004, resulting in rotational movement of the associated engaged rocker arm levers 1002, 1003. Alternatively, one of the first output rocker arm bar 1002 or the second output rocker arm bar 1004 engages the input rocker arm bar 1010. The unassociated output rocker arm levers 1002, 1004 disengage and the motion of the cam lobes is absorbed by the corresponding lost motion devices 1012, 1014. In the deactivated state, the input rocker arm lever 1010 is disengaged from the first and second output rocker arm levers 1002, 1004 and motion of the cam lobes is absorbed by lost motion devices 1012, 1014. In the deactivated state of the second mode, valve motion for the connected intake and/or exhaust valves 22, 24 may be closed.

Referring to fig. 34, another embodiment of a rocker arm system 1100 is shown. The rocker arm system 1100 includes a single output rocker arm lever 1102 that is rotatable about the engine component 120. The output rocker arm lever 1102 is configured to impart motion on either the two intake valves 22 or the two exhaust valves 24, and is configured with mechanical lash adjusters 1106, 1108. In another embodiment, the lash adjusters 1106, 1108 are hydraulic lash adjusters rather than mechanical lash adjusters. The rocker arm system 1100 also includes an input rocker arm shaft 1110 that is rotatable about the engine component 120. The input rocker arm shaft 1110 imparts a lift profile to the output rocker arm shaft 1102 via rollers 1120 that receive motion from the cam lobes.

The input rocker shaft 1110 may be operated in an activated or deactivated state. In the activated state, the input rocker arm shaft 1110 engages the output shaft 1102, resulting in rotational movement of the output rocker arm shaft 1102. Alternatively, the output rocker arm lever 1102 engages the input rocker arm lever 1110. In the deactivated state, the input rocker arm shaft 1110 is disengaged from the output rocker arm shaft 1102 and motion of the cam lobes is absorbed by the lost motion device 1112.

Referring to fig. 35, another embodiment of a rocker arm system 1200 is shown. The rocker arm system 1200 is similar to the rocker arm system 1000 and like components are designated with like reference numerals. However, the rocker system 1200 includes a second input rocker arm lever 1202 that is rotatable about the engine component 120 in response to movement imparted on the cam roller 1206 by the second cam lobe.

The second input rocker arm lever 1202 operates in two modes. In the first mode, the first input rocker arm lever 1010 is selectively engageable with both output rocker arm levers 1002, 1004. In the activated state of the second input rocker arm lever 1202 in the first mode, the second input rocker arm lever 1202 and the associated output rocker arm lever 1002 are engaged with each other, while the first input rocker arm lever 1010 is deactivated, resulting in rotational movement of the associated output rocker arm lever 1002 only with the second input rocker arm lever 1202. In the deactivated state of the second input rocker arm lever 1202, the second input rocker arm lever 1202 is disengaged from the associated output rocker arm lever 1002 and motion of the cam lobe is absorbed by the lost motion device 1204. Thus, in the first mode, the second input rocker arm lever 1202 may be in an opposite activated/deactivated state from the first input lever 1010 with respect to engagement with both output rocker arm levers 1002, 1004. Additionally, in the first mode of the second input rocker arm lever 1202, the second input rocker arm lever 1202 may be deactivated from a corresponding one of the output rocker arm levers 1002, 1004 simultaneously with the first input rocker arm lever 1010, or in an opposite activated/deactivated state of the first input rocker arm lever 1010.

In the second mode of the second input rocker arm lever 1202, the first input rocker arm lever 1010 is controlled to be selectively engageable with only one of the output rocker arm levers 1002, 1004. In the activated state of the second input rocker arm lever 1202 in the second mode, the second input rocker arm lever 1202 engages with the associated output rocker arm lever 1002, resulting in rotational movement of the associated output rocker arm lever 1002. In the deactivated state of the second input rocker arm lever 1202, the second input lever 1202 is disengaged from the associated output rocker arm lever 1002 and the cam lobe movement is absorbed by the lost motion device 1204. In the second mode of the second input rocker arm lever 1202, the second input rocker arm lever 1202 may be in a simultaneous activated state with the first input lever 1010 to engage a different one of the input rocker arm levers 1002, 1004. Additionally, in the second mode of the second input rocker arm lever 1202, the second input rocker arm lever 1202 and the first input rocker arm lever 1010 may be deactivated simultaneously or in opposition to each other.

In the activated state of the second input rocker arm lever 1202 in the first and second modes, the second input rocker arm lever 1202 may impart at least one of a normal lift event, a braking lift event, a Late Intake Valve Closing (LIVC), an Early Intake Valve Closing (EIVC), a Late Intake Valve Opening (LIVO), an Early Intake Valve Opening (EIVO), an Early Exhaust Valve Closing (EEVC), an Late Exhaust Valve Closing (LEVC), an Late Exhaust Valve Opening (LEVO), an internal exhaust gas recirculation (i-EGR) lift event, a reduced lift, an increased lift, an early extended dwell, or a late extended dwell on the second valve 22, 24 independent of the first valve 22, 24.

Referring to fig. 36, another embodiment of a rocker arm system 1300 is shown. The rocker arm system 1300 includes a combined input/output rocker arm lever 1302 that is rotatable about the engine component 120. The combined input/output rocker arm lever 1302 includes a lash adjuster 1306. The rocker arm lever assembly 1300 also includes a second output rocker arm lever 1304 that is rotatable about the engine component 120, and the second output rocker arm lever 1304 includes a lash adjuster 1308.

The combined input/output rocker arm lever 1302 functionally associated with the second output rocker arm lever 1304 imparts a fixed lift profile to the first valve and selectively imparts the same lift profile to the second output rocker arm lever 1304. The second output rocker arm lever 1304 operates in an activated or deactivated state in association with the combined input/output rocker arm lever 1302. In the activated state, the combined input/output rocker arm lever 1302 and the second output rocker arm lever 1304 are engaged, resulting in rotational movement of the second output rocker arm lever 1304. In the deactivated state, the combined input/output rocker arm lever 1302 and the second output rocker arm lever 1304 are disengaged and the cam lobe movement is absorbed by the lost motion device 1312.

The second input rocker arm member 1310, which is functionally associated with the second output rocker arm member 1304, may impart a lift profile to the second output rocker arm member 1304. The second input rocker arm lever 1310 operates in an activated/deactivated state opposite the combined input/output rocker arm lever 1302, and may also be deactivated simultaneously with the combined input/output rocker arm lever 1302.

In the activated state of the second input rocker arm lever 1310, the second input rocker arm lever 1310 engages the second output rocker arm lever 1304, resulting in rotational movement of the second output rocker arm lever 1304. In the deactivated state, the second input rocker arm lever 1310 is disengaged from the second output rocker arm lever 1304 and motion of the cam lobe is absorbed by lost motion device 1314. In the activated state, the second input rocker arm lever 1310 may impart at least one of a normal lift event, a braking lift event, a LIVC, EIVC, LIVO, EIVO, EEVO, EEVC, LEVC, LEVO, i-EGR lift event, a reduced lift, an increased lift, an advanced extended dwell, or a retarded extended dwell on a second valve independent of the first valve.

Referring to fig. 37, a rocker arm system 1400 is shown, the rocker arm system 1400 being similar to the rocker arm system 1100 and similarly comprising a single output rocker arm lever 1402 rotatable about the engine component 120. The output rocker arm lever 1402 is configured to impart motion on two intake valves 22 or two exhaust valves 24 and is configured with lash adjusters 1406, 1408. The rocker system 1400 also includes a first input rocker lever 1410 and a second input rocker lever 1412, each of which is rotatable about the engine component 120. The lost motion devices 1414, 1416 are associated with respective ones of the first input rocker arm lever 1410 and the second input rocker arm lever 1412.

Each of the first input rocker arm lever 1410 and the second input rocker arm lever 1412 is functionally associated with the output rocker arm lever 1402 and imparts a lift profile to the output rocker arm lever 1402. The second input rocker lever 1412 operates in an activated state opposite the first input rocker lever 1410 and operates in a deactivated state concurrent with or opposite the first input rocker lever 1410. In the activated state, the second input rocker arm lever 1412 engages with the output rocker arm lever 1402, resulting in rotational movement of the output rocker arm lever 1402.

In the deactivated state, the second input rocker arm lever 1412 is disengaged from the output rocker arm lever 1402 and motion of the cam lobe is absorbed by lost motion device 1416. In the activated state, the second input rocker lever 1412 may simultaneously impart at least one of a braking lift event, LIVC, EIVC, LIVO, EIVO, EEVO, EEVC, LEVC, LEVO, i-EGR lift event, reduced lift, increased lift, advanced extended dwell, or retarded extended dwell on two or more intake or exhaust valves 22, 24.

Fig. 38 to 41 illustrate other arrangements of the rocker arm system. For example, in fig. 38, the rocker arm system 1500 is similar to the rocker arm system 1400, but includes a first output rocker arm lever 1502 and a second output rocker arm lever 1504 that are selectively engageable to three input rocker arm levers 1510, 1512, 1514. In fig. 39, the rocker arm system 1600 includes a single combined input/output rocker arm lever 1602, which single combined input/output rocker arm lever 1602 is selectively engageable to both input rocker arm levers 1610, 1612.

Fig. 40 illustrates a rocker arm system 1700, the rocker arm system 1700 comprising a combined input/output rocker arm lever 1702, a second output rocker arm 1704 and two input rocker arm levers 1710, 1712. Fig. 41 illustrates a rocker arm system 1800, the rocker arm system 1800 including a single output rocker arm lever 1802 selectively engageable to three input rocker arm levers 1810, 1812, 1814.

The rocker arm systems 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 disclosed herein may be used in any type of valvetrain, including type II, type III, type IV, and/or type V valvetrains. The rocker arm systems 100, 300, 500, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 allow for multiple modes of operation to be provided at the intake and/or exhaust valves for one or more cylinders 14 of the engine 12 using a single hydraulic actuator. The operating modes may include, for example, standard lift profiles, no lift for cylinder deactivation, and alternative lift profiles. Alternative lift profiles may provide, for example, engine braking, such as four-stroke compression braking or two-stroke compression braking. Exemplary two-stroke compression brake valve lift profiles for the intake and exhaust valves are shown in FIG. 3 with IV2 and EV 2. In addition to lift profiles for compression braking, other alternative lift profiles for one or more of the intake valves 22 and/or exhaust valves 24 are also contemplated, including LIVC, EIVC, LIVO, EIVO, EEVO, EEVC, LEVC, LEVO, i-EGR lift events, reduced lift, increased lift, advanced extended dwell, or retarded extended dwell.

Any engine valve actuation system may be upgraded by using the rocker arm system of the present disclosure. For example, the valve actuation system may be upgraded from standard lift functionality for intake and exhaust valves to include cylinder deactivation or four-stroke compression braking. The valve actuation system may also be upgraded from standard lift functionality for intake and exhaust valves to include cylinder deactivation and four-stroke compression braking. The valve actuation system may also be upgraded from standard lift functionality for intake and exhaust valves to include cylinder deactivation and two-stroke compression braking.

During operation of the internal combustion engine system 10, the controller 80 may receive information from the various sensors listed above through the I/O interface, process the received information using a processor based on algorithms stored in a memory of the controller 80, and then send command signals to the various actuators through the I/O interface. For example, the controller 80 may receive information regarding cylinder deactivation conditions, engine braking requests, vehicle or engine speed requests, combustion conditions, aftertreatment temperature conditions, and/or engine load conditions. The controller 80 is configured to process conditions and/or requests, and then send one or more command signals to one or more actuators to provide cylinder deactivation and/or alternative valve lift profiles using the associated camshaft lobes and input rocker arms bars based on a control strategy.

The controller 80 may be configured to implement the disclosed cylinder deactivation and alternative valve lift strategies using a VA system 90 that incorporates the rocker arm system disclosed herein. In one embodiment, the disclosed method and/or controller configuration includes the controller 80 providing a cylinder deactivation command or an alternative valve lift command in response to a cylinder deactivation condition or an engine operating condition based on one or more signals from one or more of the plurality of sensors described above for the internal combustion engine system 10. Cylinder deactivation and alternative valve lift commands control VA mechanism 90 to switch camshaft lobes for input to provide desired intake and exhaust valve closing or opening and closing lift profiles and/or timings.

The control process implemented by the controller 80 may be performed by a processor of the controller 80 executing program instructions (algorithms) stored in a memory of the controller 80. The description herein may be implemented with an internal combustion engine system 10. In certain embodiments, the internal combustion engine system 10 further includes a controller 80, the controller 80 being structured or configured to perform certain operations to control the internal combustion engine system 10 in achieving one or more target conditions. In certain embodiments, the controller forms part of a processing subsystem that includes one or more computing devices with memory, processing, and communication hardware. The controller may be a single device or a distributed device, and the functions of the controller 80 may be performed by hardware and/or by instructions encoded on a computer readable medium.

In certain embodiments, the controller 80 includes one or more modules structured to functionally execute the operations of the controller. The description herein including modules emphasizes the structural independence of the aspects of the controller and illustrates one grouping of responsibilities and operations of the controller. Other groupings that perform similar overall operations are understood to be within the scope of the present application. The modules may be implemented in hardware and/or software on a non-transitory computer readable storage medium and the modules may be distributed over various hardware or other computer components.

Certain operations described herein include operations to interpret or determine one or more parameters. As used herein, interpreting or determining includes receiving a value by any method known in the art, including at least receiving a value from a data link or network communication, receiving an electronic signal (e.g., a voltage, frequency, current, or PWM signal) indicative of the value, receiving a software parameter indicative of the value, reading the value from a memory location on a non-transitory computer-readable storage medium, receiving the value as a runtime parameter by any means known in the art, and/or by receiving a value that can be used to calculate the interpreted or determined parameter, and/or by referencing a default value that is interpreted or determined as a parameter value.

Various aspects of the disclosure are contemplated, as described in the claims. In one aspect, a rocker arm system for an internal combustion engine is provided. The rocker arm system includes: at least one input rocker arm lever rotatable about an engine component in response to motion received from at least one camshaft lobe of a camshaft; and at least one output rocker arm lever rotatable about an engine component. The at least one output rocker arm lever is configured to control opening and closing of at least one exhaust valve or at least one intake valve associated with a cylinder of the internal combustion engine. The rocker arm system further includes at least one valve lift switch operable to connect the at least one input rocker arm lever and the at least one output rocker arm lever to each other to transfer motion from the at least one camshaft lobe to the at least one exhaust valve or the at least one intake valve and disconnect the at least one input rocker arm lever and the at least one output rocker arm lever from each other. The rocker arm system further comprises at least one additional input rocker arm lever or output rocker arm lever connectable to the at least one output rocker arm lever with at least one valve lift switch.

In an embodiment, the rocker arm system includes a lash adjuster connecting at least one of the exhaust valve or the at least one intake valve to the output rocker arm lever.

In an embodiment, the at least one input rocker arm lever includes a first input rocker arm lever and a second input rocker arm lever each rotatable about the engine component in response to movement received from a respective one of the first and second camshaft lobes of the camshaft.

In a refinement of the above embodiment, the at least one valve lift switch is operable to connect each of the first and second input rocker levers to the at least one output rocker lever. In another refinement, the at least one valve lift switch includes a first valve lift switch for selectively connecting the first input rocker arm lever to the at least one output rocker arm lever and a second valve lift switch for selectively connecting the second input rocker arm lever to the at least one output rocker arm lever.

In yet another refinement, the first valve lift switch includes a first pin assembly received in a first bore extending between the at least one output rocker arm lever and the first input rocker arm lever. The first pin assembly includes a first valve lift pin movable in the first bore from a first position in which the first valve lift pin connects the at least one output rocker arm member to the first input rocker arm member such that the at least one output rocker arm member and the first input rocker arm member rotate together about the engine component to a second position in which the first valve lift pin is received in one of the at least one output rocker arm member and the first input rocker arm member such that the first input rocker arm member is disconnected from the at least one output rocker arm member and rotation of the first input rocker arm member is not transferred to the at least one output rocker arm member. In addition, the second valve lift switch includes a second pin assembly received in a second bore extending between the at least one output rocker arm lever and the second input rocker arm lever. The second pin assembly includes a second valve lift pin movable in the second bore from a first position in which the second valve lift pin connects the at least one output rocker arm lever to the second input rocker arm lever such that the at least one output rocker arm lever and the second input rocker arm lever rotate together about the engine component to a second position in which the second valve lift pin is received in one of the at least one output rocker arm lever and the second input rocker arm lever such that the second input rocker arm lever is disconnected from the at least one output rocker arm lever and rotation of the second input rocker arm lever about the engine component is not transferred to the at least one output rocker arm lever.

In a further refinement, in the cylinder deactivation mode of operation, the first valve lift pin and the second valve lift pin are each placed in a second position in the first bore and the second bore, respectively, such that rotation of the first input rocker arm lever and rotation of the second input rocker arm lever about the engine component is not transferred to the at least one output rocker arm lever.

In a further refinement, in the standard lift mode of operation, the first valve lift pin is placed in a first position in the first bore and the second valve lift pin is placed in a second position in the second bore such that rotation of the first input rocker arm lever about the engine component is transferred to the at least one output rocker arm lever and rotation of the second input rocker arm lever about the engine component is not transferred to the at least one output rocker arm lever.

In a further refinement, in the auxiliary lift mode of operation, at least the second valve lift pin is placed in the first position in the second bore such that rotation of the second input rocker arm lever about the engine component is transferred to the at least one output rocker arm lever.

In a further refinement, the first valve lift pin includes a first shear pin part and a second shear pin part in the first bore, the first shear pin part and the second shear pin part being biased away from each other to a first position and movable from the first position to a second position via hydraulic fluid pressure. The valve lift pin further includes third and fourth shear pin features in the second bore, the third and fourth shear pin features biased toward each other to a second position and movable from the second position to the first position via hydraulic fluid pressure.

In a further refinement, the first valve lift pin includes first and second shear pin parts in abutting engagement with each other in the first bore, the first and second shear pin parts being biased to the first position and movable from the first position to the second position via hydraulic fluid pressure. The second valve lift pin in the second bore is biased to a second position and movable from the second position to the first position via hydraulic fluid pressure.

In an embodiment, the at least one input rocker lever comprises: a standard lift input rocker arm lever rotatable about an engine component in response to motion received from a first camshaft lobe of a camshaft; a first auxiliary lift input rocker arm lever rotatable about an engine component in response to movement received from a second camshaft lobe of the camshaft; and a second auxiliary lift input rocker arm lever rotatable about an engine component in response to movement received from a third camshaft lobe of the camshaft.

In a refinement of this embodiment, the at least one output rocker lever includes a rocker body having a first arm spaced apart from a second arm. The first and second arms are configured for placement about an engine component and form a space therebetween for receiving a standard lift input rocker lever. The first auxiliary lift input rocker arm member is positioned on the engine component on a side of the first arm opposite the standard lift input rocker arm member and the second auxiliary lift input rocker arm member is positioned on the engine component on a side of the second arm opposite the standard lift input rocker arm member.

In a refinement of this embodiment, each of the standard lift input rocker arm lever, the first auxiliary lift input rocker arm lever, and the second auxiliary lift input rocker arm lever includes a roller in direct or indirect contact with a respective one of the first, second, and third camshaft lobes of the camshaft.

In a further refinement, each of the standard lift input rocker arm lever, the first auxiliary lift input rocker arm lever, and the second auxiliary lift input rocker arm lever is engaged with a respective one of the first, second, and third biasing springs that contact the output rocker arm lever and bias the roller into direct or indirect contact with a respective one of the first, second, and third camshaft lobes of the camshaft.

According to another aspect, a rocker arm system for an internal combustion engine is provided. The rocker arm system includes: a first input rocker arm lever rotatable about an engine component in response to motion received from a first camshaft lobe of a camshaft; a second input rocker arm lever rotatable about an engine component in response to movement received from a second camshaft lobe of the camshaft; and at least one output rocker arm lever rotatable about an engine component. The at least one output rocker arm lever is configured to control opening and closing of at least one exhaust valve or at least one intake valve associated with a cylinder of the internal combustion engine. The rocker arm system also includes a first valve lift switch and a second valve lift switch. The first valve lift switch is operable to connect the first input rocker arm lever to the at least one output rocker arm lever to transfer motion from the first camshaft lobe to the at least one exhaust valve or the at least one intake valve. The second valve lift switch is operable to connect the second input rocker arm lever to the at least one output rocker arm lever to transfer motion from the second camshaft lobe to the at least one exhaust valve or the at least one intake valve. The first and second valve lift switches are operable to disconnect the respective first and second input rocker arm levers from the at least one output rocker arm lever such that movement from the first and second camshaft lobes is not transferred to the at least one output rocker arm lever.

In an embodiment, the first valve lift switch is received in a first bore extending between the at least one output rocker arm bar and the first input rocker arm bar, and the second valve lift switch is received in a second bore extending between the at least one output rocker arm bar and the second input rocker arm bar.

In an embodiment, the first and second valve lift switches are each hydraulically controlled to connect and disconnect corresponding ones of the first and second input rocker arm levers to and from the at least one output rocker arm lever.

In an embodiment, the rocker arm system includes a third input rocker arm lever rotatable about the engine component in response to movement received from a third camshaft lobe of the camshaft. The third input rocker arm lever can be connected to the at least one output rocker arm lever with a second switch to transfer motion from the third camshaft lobe to the at least one exhaust valve or the at least one intake valve. The third rocker arm lever is disconnectable from the at least one output rocker arm lever such that movement from the third camshaft lobe is not transferred to the at least one output rocker arm lever.

In an embodiment, the rocker arm system comprises a second output rocker arm lever rotatable about an engine component. The second output rocker arm lever is configured to control opening and closing of at least one other exhaust valve or at least one other intake valve associated with a cylinder of the internal combustion engine. The first switch is operable to connect and disconnect the second output rocker arm lever with the at least one output rocker arm lever.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described. Those skilled in the art will appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

In reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least one portion" are used, it is not intended that the claims be limited to only one item unless explicitly stated to the contrary in the claims. When the language "at least a portion" and/or "a portion" is used, the item may include a portion and/or the entire item unless specifically stated to the contrary.

Claims

1. A rocker arm system for an internal combustion engine, the rocker arm system comprising:

At least one input rocker arm lever rotatable about an engine component in response to movement received from at least one camshaft lobe of a camshaft;

at least one output rocker arm lever rotatable about the engine component, wherein the at least one output rocker arm lever is configured to control opening and closing of at least one exhaust valve or at least one intake valve associated with a cylinder of the internal combustion engine;

at least one valve lift switch operable to:

Connecting the at least one input rocker arm lever and the at least one output rocker arm lever to each other to transfer motion from the at least one camshaft lobe to the at least one exhaust valve or the at least one intake valve; and

Disconnecting the at least one input rocker lever and the at least one output rocker lever from each other; and

At least one additional input rocker arm lever or output rocker arm lever connectable to the at least one output rocker arm lever with the at least one valve lift switch.

2. The rocker arm system of claim 1 further comprising a lash adjuster connecting at least one of the exhaust valve or the at least one intake valve to the output rocker arm lever.

3. The rocker arm system of claim 1 wherein the at least one input rocker arm lever comprises first and second input rocker arm levers each rotatable about the engine component in response to movement received from a respective one of the first and second camshaft lobes of the camshaft.

4. The rocker system of claim 3 wherein the at least one valve lift switch is operable to connect each of the first and second input rocker bars to the at least one output rocker bar.

5. The rocker arm system of claim 3 wherein the at least one valve lift switch includes a first valve lift switch for selectively connecting the first input rocker arm lever to the at least one output rocker arm lever and a second valve lift switch for selectively connecting the second input rocker arm lever to the at least one output rocker arm lever.

6. The rocker arm system of claim 5 wherein:

The first valve lift switch includes a first pin assembly received in a first bore extending between the at least one output rocker arm member and the first input rocker arm member, the first pin assembly including a first valve lift pin movable in the first bore from a first position in which the first valve lift pin connects the at least one output rocker arm member to the first input rocker arm member such that the at least one output rocker arm member and the first input rocker arm member rotate together about the engine component to a second position in which the first valve lift pin is received in one of the at least one output rocker arm member and the first input rocker arm member such that the first input rocker arm member is disconnected from the at least one output rocker arm member and rotation of the first input rocker arm member is not transferred to the at least one output rocker arm member; and

The second valve lift switch includes a second pin assembly received in a second bore extending between the at least one output rocker arm lever and the second input rocker arm lever, the second pin assembly including a second valve lift pin movable in the second bore from a first position in which the second valve lift pin connects the at least one output rocker arm lever to the second input rocker arm lever such that the at least one output rocker arm lever and the second input rocker arm lever rotate together about the engine component to a second position in which the second valve lift pin is received in one of the at least one output rocker arm lever and the second input rocker arm lever such that the second input rocker arm lever is disconnected from the at least one output rocker arm lever and rotation of the second input rocker arm lever about the engine component is not transferred to the at least one output rocker arm lever.

7. The rocker arm system of claim 6 wherein, in a cylinder deactivation mode of operation, the first and second valve lift pins are each placed in the second positions in the first and second bores, respectively, such that rotation of the first and second input rocker arm levers about the engine component is not transferred to the at least one output rocker arm lever.

8. The rocker arm system of claim 6 wherein in a standard lift mode of operation, the first valve lift pin is placed in the first position in the first bore and the second valve lift pin is placed in the second position in the second bore such that rotation of the first input rocker arm lever about the engine component is transferred to the at least one output rocker arm lever and rotation of the second input rocker arm lever about the engine component is not transferred to the at least one output rocker arm lever.

9. The rocker arm system of claim 6 wherein, in an auxiliary lift mode of operation, at least the second valve lift pin is placed in the first position in the second bore such that rotation of the second input rocker arm lever about the engine component is transferred to the at least one output rocker arm lever.

10. The rocker arm system of claim 6 wherein:

The first valve lift pin includes first and second shear pin features in the first bore, the first and second shear pin features biased away from each other to the first position and movable from the first position to the second position via hydraulic fluid pressure; and

The valve lift pin includes third and fourth shear pin features in the second bore, the third and fourth shear pin features biased toward each other to the second position and movable from the second position to the first position via hydraulic fluid pressure.

11. The rocker arm system of claim 6 wherein:

The first valve lift pin includes first and second shear pin parts in abutting engagement with each other in the first bore, the first and second shear pin parts biased to the first position and movable from the first position to the second position via hydraulic fluid pressure; and

The second valve lift pin in the second bore is biased to the second position and movable from the second position to the first position via hydraulic fluid pressure.

12. The rocker system of claim 1 wherein the at least one input rocker lever comprises:

A standard lift input rocker arm lever rotatable about the engine component in response to movement received from a first camshaft lobe of the camshaft;

A first auxiliary lift input rocker arm lever rotatable about the engine component in response to movement received from a second camshaft lobe of the camshaft; and

A second auxiliary lift input rocker arm lever rotatable about the engine component in response to movement received from a third camshaft lobe of the camshaft.

13. The rocker system of claim 12 wherein the at least one output rocker arm lever includes a rocker arm body having a first arm spaced apart from a second arm, the first and second arms being configured for placement about the engine component and forming a space therebetween for receiving the standard lift input rocker arm lever, the first auxiliary lift input rocker arm lever being positioned on the engine component on a side of the first arm opposite the standard lift input rocker arm lever and the second auxiliary lift input rocker arm lever being positioned on the engine component on a side of the second arm opposite the standard lift input rocker arm lever.

14. The rocker arm system of claim 13 wherein each of the standard lift input rocker arm lever, the first auxiliary lift input rocker arm lever and the second auxiliary lift input rocker arm lever includes a roller in direct or indirect contact with a respective one of the first, second and third camshaft lobes of the camshaft.

15. The rocker system of claim 14 wherein each of the standard lift input rocker arm lever, the first auxiliary lift input rocker arm lever and the second auxiliary lift input rocker arm lever is engaged with a respective one of a first biasing spring, a second biasing spring and a third biasing spring that contact the output rocker arm lever and bias the roller into direct or indirect contact with a respective one of the first, second and third camshaft lobes of the camshaft.

16. A rocker arm system for an internal combustion engine, the rocker arm system comprising:

A first input rocker arm lever rotatable about an engine component in response to movement received from a first camshaft lobe of a camshaft;

A second input rocker arm lever rotatable about an engine component in response to movement received from a second camshaft lobe of the camshaft;

at least one output rocker arm lever rotatable about the engine component, the at least one output rocker arm lever configured to control opening and closing of at least one exhaust valve or at least one intake valve associated with a cylinder of the internal combustion engine;

A first valve lift switch and a second valve lift switch, wherein:

the first valve lift switch is operable to connect the first input rocker arm lever to the at least one output rocker arm lever to transfer motion from the first camshaft lobe to the at least one exhaust valve or the at least one intake valve;

The second valve lift switch is operable to connect the second input rocker arm lever to the at least one output rocker arm lever to transfer motion from the second camshaft lobe to the at least one exhaust valve or the at least one intake valve; and

The first and second valve lift switches are operable to disconnect the respective first and second input rocker arm levers from the at least one output rocker arm lever such that movement from the first and second camshaft lobes is not transferred to the at least one output rocker arm lever.

17. The rocker arm system of claim 16 wherein:

The first valve lift switch is received in a first bore extending between the at least one output rocker lever and the first input rocker lever; and

The second valve lift switch is received in a second bore extending between the at least one output rocker arm lever and the second input rocker arm lever.

18. The rocker arm system of claim 16 wherein the first and second valve lift switches are each hydraulically controlled to connect and disconnect corresponding ones of the first and second input rocker arm members from the at least one output rocker arm member.

19. The rocker arm system of claim 16, further comprising a third input rocker arm lever rotatable about the engine component in response to movement received from a third camshaft lobe of the camshaft, wherein:

the third input rocker arm lever is connectable to the at least one output rocker arm lever with the second switch to transfer motion from the third camshaft lobe to the at least one exhaust valve or the at least one intake valve; and

The third rocker arm lever is disconnectable from the at least one output rocker arm lever such that movement from the third camshaft lobe is not transferred to the at least one output rocker arm lever.

20. The rocker arm system of claim 16, further comprising:

A second output rocker arm lever rotatable about the engine component, the second output rocker arm lever configured to control opening and closing of at least one other exhaust valve or at least one other intake valve associated with a cylinder of the internal combustion engine; and

Wherein the first switch is operable to connect and disconnect the second output rocker lever with the at least one output rocker lever.