System for facilitating cylinder deactivation and 1.5-stroke engine braking operation in internal combustion engines

Abstract

The valve actuation system includes a cylinder deactivation controller operably connected to and in fluid communication with the intake and exhaust deactivation device for at least one cylinder. The valve actuation system further includes an engine brake controller operably connected to and in fluid communication with the engine brake actuator for the at least one cylinder. The brake-dependent deactivation controller is disposed between the cylinder deactivation controller and the intake deactivation device and is in fluid communication with the cylinder deactivation controller and the intake deactivation device and is in fluid communication with the engine brake controller via a control input. The brake-dependent deactivation controller is configured, based on the control input, to allow hydraulic fluid flow in a hydraulic fluid control passage for the intake deactivation device when in a non-1.5-stroke engine braking mode in a first state and to vent the hydraulic fluid control passage for the intake deactivation device when in a 1.5-stroke engine braking mode in a second state.

Description

[Technical Field]

[0001] The present disclosure relates generally to internal combustion engines, and more particularly to a valve actuation system for facilitating cylinder deactivation and 1.5 stroke engine braking operation in such engines. [Background technology]

[0002] FIG. 1 is a partial schematic diagram of an internal combustion engine 100, including a cross-sectional view of an engine cylinder 102 and associated valve actuation system, according to the prior art. While a single cylinder 102 is shown in FIG. 1 for ease of illustration only, it is understood that an internal combustion engine often includes multiple such cylinders that drive a crankshaft (not shown). The engine cylinder 102 has a piston 104 disposed therein that repeatedly reciprocates up and down during both positive power operation of the cylinder 102 (i.e., combustion of fuel to drive the piston 104 and drivetrain) and engine braking operation (i.e., using the piston 104 to achieve air compression and power absorption via the drivetrain). The top of each cylinder 102 may have at least one intake valve 106 and at least one exhaust valve 108. The intake valve 106 and exhaust valve 108 are opened and closed to provide communication with an intake gas passage 110 and an exhaust gas passage 112, respectively. Valve actuation forces for opening the intake valves 106 and exhaust valves 108 are transmitted by respective valve trains 114, 116. Such valve actuation forces (indicated by dashed arrows) may then be provided by respective primary and / or auxiliary motion sources 118, 120, 122, 124, such as rotating cams. As used herein, the term "primary" refers to so-called main-event engine valve motion, i.e., valve motion used during positive force generation, while the term "auxiliary" refers to other engine valve motions other than positive force generation (e.g., compression-release (CR) braking, bleeder braking, cylinder decompression, brake gas recirculation (BGR), etc.) or in addition to positive force generation (e.g., internal exhaust gas recirculation (IEGR), variable valve actuations (VVA), Miller / Atkinson cycle, swirl control, etc.).

[0003] Generally, CR engine braking occurs when an engine's cylinders operate without fuel, essentially acting as air compressors, thereby providing vehicle deceleration power through the vehicle's drivetrain. So-called two-stroke or high-power-density CR braking provides two CR events for each engine cycle (a given cylinder's cycle includes the intake, compression, expansion, and exhaust strokes of the corresponding piston 104), which provides increased retarding power compared to conventional CR systems that provide only a single CR event for each engine cycle. Two-stroke CR engine braking requires that the primary intake and exhaust valve actuation motion be "lost" (i.e., not transmitted to the engine valves 106, 108) in favor of auxiliary valve actuation motion to implement high-power-density engine braking. To implement two-stroke CR engine braking, the valve actuation system typically incorporates a cylinder deactivation (CDA) system that operates to decouple the intake valves 106 and exhaust valves 108 from their respective valve actuation motion sources 118, 120, 122, 124, thereby achieving the aforementioned interruption of the primary intake and exhaust valve events.

[0004] In the context of FIG. 1 , lost motion components 126, 128, referred to herein as “deactivators,” are provided to the respective intake and exhaust valve trains 114, 116 to effect cylinder deactivation. Each deactivator 130, 132 is controlled by a corresponding deactivator controller 130, 132, which in turn is controlled by an engine controller 134. The engine controller 134 may include any electronic, mechanical, hydraulic, electro-hydraulic, or other type of control device for communicating with and controlling the operation of the deactivator controllers 130, 132. For example, the engine controller 134 may be implemented by a microprocessor and corresponding memory storing executable instructions used to implement the necessary control functions, as known in the art. It will be understood that other functionally equivalent implementations of the engine controller 134, such as a suitable programmed application-specific integrated circuit (ASIC), may equally be used. Similarly, it is known in the art to implement such deactivation devices using hydraulically controlled lost motion components that can be switched between an activated / locked / uncollapsed state in which engine valve actuation is transmitted to the engine valve, and a deactivated / unlocked / collapsed state in which valve actuation motion is not transmitted to the engine valve, thereby effectively deactivating the corresponding cylinder.

[0005] An example of such a hydraulically controlled lost motion component is shown and described in U.S. Pat. No. 9,790,824 ("the '824 patent"), owned by the same assignee as the present application, which describes a locking mechanism that is normally in a locked / uncollapsed, or motion-transmitting, state and switches to an unlocked / collapsed, or motion-absorbing, state upon application of hydraulic fluid. Furthermore, each locking mechanism described in the '824 patent may be applied to an individual engine valve (e.g., in a rocker arm that actuates a single engine valve) or to multiple engine valves (e.g., in a valve bridge used to actuate two or more engine valves). When a hydraulically controlled deactivation device is used, the deactivation device controllers 130, 132 are typically implemented using high-speed solenoids that control the flow of hydraulic fluid (e.g., motor oil) to the hydraulically controlled deactivation device.

[0006] Given the common feature requiring separation of the main intake and exhaust valve events, a valve actuation system can readily be envisioned that provides both two-stroke HPD CR engine braking and CDA operation.

[0007] However, compatibility of CDA operation with other forms of CR engine braking is not easily achieved. For example, in so-called 1.5-stroke CR engine braking systems, the main exhaust event is deactivated. However, the main intake valve event is not deactivated, and no additional intake lift event is provided to support the second CR event. That is, the normal main intake valve event is provided for the first CR event, and the gas used in the second compression-release event is generated solely by exhaust manifold gas recirculation, without drawing air from the intake manifold. Therefore, valve actuation systems that simultaneously provide CDA operation for both the exhaust and intake valves are often incompatible with 1.5-stroke CR engine braking if only the main exhaust event, but not the main intake event, is required.

[0008] To promote compatibility of CDA with 1.5-stroke CR engine braking, commonly owned U.S. Pat. No. 11,162,438 (the "'438 patent") teaches the provision of a "blocking system" for selectively preventing disabling of the primary intake valve event during 1.5-stroke CR engine braking. In certain embodiments, such a blocking system is implemented by a spool valve provided with the "CDA mechanism" or a deactivation device disposed in the intake valve train of each cylinder of the engine. During CDA operation of the engine, each of the spool valves is operated to allow hydraulic fluid flow to and activation of the deactivation device associated with the intake valve, thereby enabling deactivation of the intake valve. However, when 1.5-stroke CR engine braking operation is required, in addition to the operation of the CDA system required to disable the primary exhaust valve event, the spool valve is controlled to inhibit operation of the deactivation device associated with the intake valve, i.e., to block hydraulic fluid flow to and activation of the deactivation device associated with the intake valve.

[0009] While the '438 patent provides a viable solution for providing 1.5-stroke CR engine braking, further improvements are desirable. For example, the addition of a spool valve assembly to each cylinder's intake valve train increases the cost, complexity, and weight of a given engine. Furthermore, even if the flow path to the intake-related deactivation device is blocked by the spool valve taught by the '438 patent, hydraulic fluid trapped between the spool valve and the intake deactivation device may remain sufficiently pressurized during 1.5-stroke CR engine braking to still enable operation of the intake deactivation device and disable the primary intake valve event during 1.5-stroke CR engine braking. This may degrade the performance of the 1.5-stroke CR engine braking operation. Summary of the Invention

[0010] The present disclosure relates to a valve actuation system for facilitating cylinder deactivation and 1.5-stroke engine braking in an internal combustion engine having at least one cylinder, each cylinder including at least one intake valve and corresponding hydraulically controlled intake deactivation device, at least one exhaust valve and corresponding hydraulically controlled exhaust deactivation device, and a hydraulically controlled engine brake actuator. Such a valve actuation system includes a cylinder deactivation controller operably connected to and in fluid communication with the intake deactivation device and exhaust deactivation device for the at least one cylinder. Such a valve actuation system further includes an engine brake controller operably connected to and in fluid communication with the engine brake actuator for the at least one cylinder. A brake-dependent deactivation controller is disposed between the cylinder deactivation controller and the intake deactivation device, and is in fluid communication with the cylinder deactivation controller and the intake deactivation device, and is in fluid communication with the engine brake controller via a control input of the brake-dependent deactivation controller. In one embodiment, the brake-dependent deactivation device controller is configured in a first state to allow hydraulic fluid flow in the hydraulic fluid control passage for the intake deactivation device when in the non-1.5-stroke engine braking mode according to hydraulic fluid selectively applied to the control input by the engine brake controller. Further in this embodiment, the brake-dependent deactivation device controller is also configured in a second state to vent the hydraulic fluid control passage for the intake deactivation device when in the 1.5-stroke engine braking mode according to hydraulic fluid selectively applied to the control input by the engine brake controller.

[0011] In one embodiment, the cylinder deactivator controller and engine brake controller may include normally off solenoids.

[0012] In one embodiment, the brake-dependent deactivation controller includes a spool valve configured to operate in a first position providing fluid communication between the cylinder deactivation controller and the intake deactivation device and further configured to operate in a second position providing fluid communication between the intake deactivation device and a vent passageway, the vent passageway may include a central bore formed in the spool valve. In another embodiment, the spool valve may include a spool slidably disposed within the spool valve bore, the spool valve bore being in fluid communication with the cylinder deactivation device controller through a first hydraulic passageway and in fluid communication with the intake deactivation device through a second hydraulic passageway offset from the first hydraulic passageway. In this embodiment, the spool valve bore may be further in fluid communication with the vent passageway such that, when the spool is operated in the first position, the spool valve bore provides fluid communication between the first hydraulic passageway and the second hydraulic passageway while simultaneously blocking the vent passageway, and when the spool is operated in the second position, the spool valve bore provides fluid communication between the second hydraulic passageway and the vent passageway while simultaneously blocking the first hydraulic passageway.

[0013] In one embodiment, the intake and exhaust deactivators may include normally locked / motion transmitting lost motion components. Further to this embodiment, the engine brake actuator may include normally unlocked / motion absorbing lost motion components.

[0014] In yet another embodiment, the engine controller is operatively coupled to the cylinder deactivation controller and the engine brake controller and is operative to activate the cylinder deactivation controller subsequent to activation of the engine brake controller when initiating the 1.5-stroke engine braking mode. Further to this embodiment, the engine controller may be further operative to activate the cylinder deactivation controller subsequent to activation of the engine brake controller when initiating the 1.5-stroke engine braking mode.

[0015] These and other features of the present disclosure will become apparent upon reference to the following detailed description.

[0016] The foregoing and other features and advantages are discussed in detail in the following non-limiting description of specific embodiments, taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic partial cross-sectional view of an internal combustion engine showing a typical arrangement of a deactivator and deactivator controller according to the prior art; [Figure 2] 1 illustrates a schematic diagram of a valve actuation system including a brake dependent deactivator controller according to the present disclosure. [Figure 3] 1 illustrates a schematic diagram of a valve actuation system including a brake dependent deactivator controller according to the present disclosure. [Figure 4] 1 illustrates a schematic diagram of a valve actuation system including a brake dependent deactivator controller according to the present disclosure. [Figure 5] 1 illustrates a schematic diagram of a valve actuation system including a brake dependent deactivator controller according to the present disclosure. [Figure 6] 1 illustrates an example of a brake dependent deactivation device controller in the form of a two-channel vent spool valve and its operation according to the present disclosure. [Figure 7] 1 illustrates an example of a brake dependent deactivation device controller in the form of a two-channel vent spool valve and its operation according to the present disclosure. [Figure 8] 10A and 10B illustrate schematically alternative embodiments of a spool valve according to the present disclosure; [Figure 9] 10A and 10B illustrate schematically alternative embodiments of a spool valve according to the present disclosure; DETAILED DESCRIPTION OF THE INVENTION

[0018] As used herein, phrases substantially similar to "at least one of A, B, or C" are intended to be construed disjunctively, i.e., requiring A or B or C, or any combination thereof, unless otherwise stated or implied by context. Further, phrases substantially similar to "at least one of A, B, and C" are intended to be conjunctively, i.e., requiring at least one of A, at least one of B, and at least one of C, unless otherwise stated or implied by context. Further, the term "substantially" or similar words requiring subjective comparison are intended to mean "within manufacturing tolerances," unless otherwise stated or implied by context.

[0019] As used herein, the phrase "operably connected" refers to at least a functional relationship between two elements and can encompass configurations in which two elements are directly connected to each other, i.e., without intervening elements, or indirectly connected to each other, i.e., connected with intervening elements.

[0020] A feature of the present disclosure is the use of a brake dependent deactivator controller for selectively venting hydraulic passages used to control operation of the intake deactivator. The brake dependent deactivator controller is configured to operate under control of the engine brake controller and to allow hydraulic fluid flow to the intake deactivator in a first state or to allow venting of hydraulic passages leading to the intake deactivator in a second state.

[0021] 2-4 schematically illustrate a valve actuation system 200 featuring a brake-dependent deactivation device controller in the form of a vent spool valve 250. In particular, the valve actuation system 200 includes intake deactivation devices 212, 222, exhaust deactivation devices 214, 224, and engine brake actuators 216, 226 corresponding to a plurality of engine cylinders 210, 220, respectively. While not shown in FIGS. 2-4, each of the illustrated cylinders 210, 220 includes one or more intake valves and one or more exhaust valves. As known in the art, the intake deactivation devices 212, 222 may be configured and deployed to operate on one or more intake valves, and the exhaust deactivation devices 214, 224 may be configured and deployed to operate on one or more exhaust valves. Furthermore, each of the engine brake actuators 216, 226 may be configured and deployed to operate on at least one exhaust valve.

[0022] In general, the intake deactivators 212, 224, the exhaust deactivators 216, 226, and the engine brake actuators 216, 226 may be lost motion components of the type described in the '824 patent, i.e., hydraulically controlled to be in a locked or motion-transmitting state in which the lost motion component is maintained in a rigid state so that valve-actuating motion applied to the lost motion component is transmitted by the lost motion component, or in an unlocked or motion-absorbing state in which the lost motion component is maintained in a compliant state so that valve-actuating motion applied to the lost motion component is absorbed (i.e., not transmitted) by the lost motion component. Furthermore, as is known in the art, such lost motion components (including those taught in the '824 patent) may be configured in a normally locked / motion-transmitting state or a normally unlocked / motion-absorbing state. That is, in the absence of an applied control input (e.g., hydraulic fluid) for activation, the former types of lost motion components are maintained in their locked / motion-transmitting state, while the latter types of lost motion components are maintained in their unlocked / motion-absorbing state. With this distinction in mind, in one exemplary embodiment, the intake and exhaust deactivation devices 212, 224, 214, 224 may be implemented using normally locked / motion transmitting lost motion components, while the engine braking actuators 216, 226 may be implemented using normally unlocked / motion absorbing lost motion components. Thus, the default state of the engine is one in which CDA and engine braking operation are disabled, while normal positive generating operation is enabled.

[0023] The operation of intake and exhaust deactivation devices 212, 224, 214, 224 is controlled by a CDA controller 230, while the operation of engine brake actuators 216, 226 is controlled by an engine brake controller 232. For example, if intake and exhaust deactivation devices 212, 224, 214, 224 and engine brake actuators 216, 226 are hydraulically controlled lost motion components (such as those taught in the '824 patent), CDA controller 230 and engine brake controller 232 may each comprise a high-speed solenoid operating under the control of an engine controller ( FIG. 1 ). In such an embodiment, controllers 230, 232 are operably connected to a source 240 of pressurized hydraulic fluid, such as an engine oil pump and engine oil distribution network. An output port 231 of CDA controller 230 is operably connected to an exhaust deactivation device hydraulic manifold or passage 242 and an intake deactivation device hydraulic manifold or passage 244. As shown, a selectable vent spool valve 250 is disposed between the CDA controller 230 and the intake deactivator hydraulic manifold 244. Additionally, an output port 233 of the engine brake controller 232 is operatively connected to an engine brake hydraulic manifold or passage 246. In one embodiment, each of the controllers 230, 232 operates in a normally off state such that hydraulic fluid from the hydraulic fluid source 240 cannot enter the exhaust deactivator hydraulic manifold 242, the intake deactivator hydraulic manifold 244, or the engine brake hydraulic manifold 246.

[0024] Spool valve 250 is biased to a default or first position (to the left as shown in FIG. 2 ) by spool valve spring 252. Spool valve 250 is also operatively connected to and in fluid communication with engine brake hydraulic manifold 246 (and engine brake controller 232) via control input 251 opposite spool valve spring 252. In this manner, as described in further detail below, the presence of pressurized hydraulic fluid within engine brake hydraulic manifold 246 can overcome the bias applied by spool valve spring 252, thereby causing spool valve 250 to translate (to the right as shown in FIG. 1 ; see FIG. 4 ) to its activated or second position. Spool valve 250 includes at least one annular port 254 defined on an outer surface of spool valve 250 and at least one vent port 256 defining a hydraulic passageway between the outer surface of spool valve 250 and a vent channel 258 defined internally as a central bore within the spool valve. In one embodiment, the vent channel 258 is open to a space defined within the valve overhead, for example. As shown in Figure 2, in the default position of the spool valve 250, the annular port 254 is aligned with the exhaust deactivator hydraulic manifold 242 and the intake deactivator hydraulic manifold 244, thereby providing fluid communication between the two. Meanwhile, in the actuated position of the spool valve 250, the vent port 256 is aligned only with the intake deactivator hydraulic manifold 244, while the exhaust deactivator hydraulic manifold 244 is sealed where it contacts the spool valve 250 (Figure 4).

[0025] Thus configured, valve actuation system 200 can be controlled to provide various desired operating modes according to the operating states of CDA controller 230 and engine brake controller 232 as commanded by the engine controller. As shown in FIG. 2 , both CDA controller 230 and engine brake controller 232 are controlled to remain in an off (preferably default) state so that hydraulic fluid from hydraulic fluid source 240 cannot enter the respective intake deactivator hydraulic manifold 244, exhaust deactivator hydraulic manifold 244, or engine brake hydraulic manifold 246. As a result, both intake and exhaust deactivators 212, 224 remain in their default locked / motion transmitting state so that main valve actuation motion is transmitted to the respective intake and exhaust valves. Similarly, engine brake actuators 216, 226 are also enabled to remain in their default unlocked / motion absorbing state so that high power density engine brake valve actuation motion is not transmitted to the exhaust valves. In this manner, valve actuation system 200 is configured to provide positive power generation operation of the engine.

[0026] When CDA operation of the engine is desired, as shown in FIG. 3 , CDA controller 230 can be activated (energized), while engine brake controller 232 remains deactivated (de-energized). As shown, this allows hydraulic fluid to flow from hydraulic supply 240 and out output port 231 of CDA controller 230. Next, the hydraulic fluid enters exhaust hydraulic fluid manifold 242, crosses annular port 254 of spool valve 250 (which remains in its default position), and enters intake hydraulic fluid manifold 244. The presence of pressurized hydraulic fluid in exhaust hydraulic fluid manifold 242 and intake hydraulic fluid manifold 244 controls the respective intake deactivation devices 212, 222 and exhaust deactivation devices 214, 224 to switch to their unlocked / motion absorbing states, such that such valve actuation motion (e.g., primary valve actuation) that would otherwise be imparted by such lost motion components is instead absorbed and lost. In this manner, valve actuation system 200 is configured to provide CDA operation of the engine.

[0027] When 1.5-stroke CR engine braking operation of the engine is desired, both engine brake controller 232 and CDA controller 230 are activated (energized). Generally, it is desirable to activate engine brake controller 232 and CDA controller 230 in a manner that avoids deactivating the intake valves simultaneously with activation of engine brake actuators 216, 226. For illustrative purposes, activation of engine brake controller 232 and CDA controller 230 is shown sequentially in Figures 4 and 5, i.e., engine brake controller 232 is activated, followed by CDA controller 230. However, this is not a requirement, and in some embodiments, engine brake controller 232 and CDA controller 230 are activated substantially simultaneously (within manufacturing tolerances), or in any event, such that CDA controller 230 is not activated earlier than engine brake controller 232.

[0028] Thus, as shown in FIG. 4, engine brake controller 232 may initially be activated (energized) while CDA controller 232 remains deactivated (de-energized). As shown, this allows hydraulic fluid to flow from hydraulic supply 240 and exit output port 233 of engine brake controller 232. The hydraulic fluid then enters engine brake hydraulic fluid manifold 246. The presence of pressurized hydraulic fluid in engine brake hydraulic fluid manifold 246 controls engine brake actuators 216, 226 to switch to their locked / motion transmitting state such that such valve actuation motion that would otherwise be lost by such lost motion components (e.g., 1.5-stroke CR engine brake valve actuation) is instead transmitted to their respective exhaust valves. Simultaneously, the presence of pressurized hydraulic fluid in engine brake hydraulic fluid manifold 246 is applied to control input 251 of spool valve 250, thereby initiating the transition of the spool valve from its default position to its activated position. As shown in FIG. 4, spool valve 250 has not yet transitioned to its activated position.

[0029] 5, following (or, again, at least thereafter) activation of engine brake controller 232, CDA controller 230 is also activated (energized) and outputs hydraulic fluid from its output port 231 to exhaust hydraulic fluid manifold 242 as shown. Simultaneously, pressurized hydraulic fluid is supplied to control input 251 of spool valve 250 via engine brake hydraulic fluid manifold 246, thereby overcoming the biasing force of spool valve spring 252, thereby allowing spool valve 250 to assume its second or activated position, as further shown in FIG. As a result, the vent port 256 of the spool valve 250 is aligned with the intake hydraulic fluid manifold 244, which is then allowed to vent any hydraulic fluid therein out through the vent channel 258, thereby allowing the intake deactivation devices 212, 222 to remain in (or switch back to) the unlocked / motion absorbing state regardless of activation of the CDA controller 230. Because the vent port 256 only allows venting of the intake hydraulic fluid manifold 244, while the exhaust hydraulic fluid manifold 242 is sealed from the intake hydraulic fluid manifold 244 and the vent channel 258 by the spool valve 250, the necessary provision of the main intake valve event and simultaneous suppression of the main exhaust valve event required for 1.5-stroke CR engine braking is provided.

[0030] 2-5 show a CDA controller 230 / engine brake controller 232 paired to control the operation of two engine cylinders 210, 220. However, it is understood that such a controller pair may be used to control only one cylinder (as indicated by the ellipses for manifolds 242, 244, 246) or more than two cylinders. For example, in a six-cylinder engine, a single CDA controller / engine brake controller pair may be used to control the operation of all six cylinders of the engine as described above. Alternatively, multiple CDA controller / engine brake controller pairs may be provided, each associated with a subgroup of cylinders. For example, again referring to a six-cylinder engine, a first CDA controller / engine brake controller pair may be configured to control cylinders 1-3, while a second CDA controller / engine brake controller pair may be configured to control cylinders 4-6, or three CDA controller / engine brake controller pairs may be provided to control cylinders 1 and 2 as a first group, cylinders 3 and 4 as a second group, and cylinders 5 and 6 as a third group. Still other configurations will be apparent to those skilled in the art depending on the number of cylinders and engine braking requirements of the engine.

[0031] It will further be appreciated that a single CDA controller / engine brake controller pair can control multiple subgroups of cylinders via a single spool valve with multiple annular and vent ports. An example of such an embodiment is shown with reference to FIGS. 6 and 7. In particular, FIGS. 6 and 7 show a spool valve 602 having a spool valve spring 604 operably connected to the right end (as shown in FIGS. 6 and 7) of the spool valve 602. In this embodiment, a pair of annular ports 606, 608 and a pair of vent ports 610, 612 are also shown, in addition to a vent channel 614 established within the spool valve 602. Additionally, the leftmost end of the spool valve 602 is configured to be in fluid communication with an engine brake hydraulic fluid manifold 620. A first intake hydraulic fluid manifold 622 and a second intake hydraulic fluid manifold 624 are also shown. The first intake hydraulic fluid manifold 622 may be operably connected to an intake deactivation device corresponding to a first group of one or more cylinders (in a manner similar to that shown in Figures 2-5), while the second intake hydraulic fluid manifold 624 may be operably connected to an intake deactivation device corresponding to a second group of one or more cylinders. Although not shown in Figures 6 and 7, corresponding first and second exhaust hydraulic fluid manifolds (operably connected to exhaust deactivation devices for the first and second groups of cylinders and aligned with respective ones of the first and second intake hydraulic fluid manifolds 622, 624) may be provided.

[0032] 6 , the spool valve 602 is maintained in its default position when there is no hydraulic fluid in the engine brake hydraulic fluid manifold 624, thereby aligning the annular ports 606, 608 with a respective one of the first intake hydraulic fluid manifold 622 and the second intake hydraulic fluid manifold 624. As described above, when hydraulic fluid is provided by a first CDA controller for the first intake / exhaust hydraulic fluid manifold and a second CDA controller for the second intake / exhaust hydraulic fluid manifold, the default position of the spool valve 602 allows hydraulic fluid to enter both the first intake hydraulic fluid manifold 622 and the second intake hydraulic fluid manifold 624.

[0033] 7, supplying hydraulic fluid into engine brake hydraulic fluid manifold 620 causes spool valve 602 to translate to its actuated position. As a result, first vent port 610 is aligned with first intake hydraulic fluid manifold 622 and second vent port 612 is aligned with second intake hydraulic fluid manifold 624, thereby allowing hydraulic fluid in intake hydraulic fluid manifolds 622, 624 to vent through their respective vent ports 610, 612 and vent channel 614.

[0034] 6 and 7 also show a keyed channel 628 and corresponding key 626 defined longitudinally along the inner surface of the bore in which the spool valve 602 is slidably disposed. The key 626, supported by the spool valve 602, aligns with and travels through the keyed channel 628 as the spool valve 602 translates within its bore, thereby preventing rotation of the spool valve 602 within the bore. Preventing the spool valve 602 from rotating within its bore ensures proper alignment of the vent ports 610, 612 with the corresponding first and second intake hydraulic fluid manifolds 622, 624. In an alternative embodiment, the vent ports 610, 612 may comprise multiple circumferentially spaced, radially extending passages (similar to those depicted in FIGS. 6 and 7) aligned with one another along the longitudinal axis of the spool valve 602 and in fluid communication with the vent channel 614. If the circumferential spacing of such ventilation ports 610, 612 is sufficiently close to ensure fluid communication between at least one of the ventilation ports 610, 612 and the corresponding first and second intake hydraulic fluid manifolds 622, 624 regardless of rotation of the spool valve 602, the key 626 and key channel 628 may not be required.

[0035] It should also be noted that the vent ports 256, 610, 612 shown in this disclosure are all shown to have a smaller diameter or cross-sectional area than the diameter or cross-sectional area of ​​the intake hydraulic fluid manifolds 244, 622, 624 with which they are periodically aligned. This is done to ensure controlled venting of hydraulic fluid from such manifolds.

[0036] 8 and 9 illustrate an alternative embodiment of a spool valve 800 according to the present disclosure. In contrast to the spool valves 250, 602 shown in FIGS. 2-7, the spool valve 800 includes an annular port 810 but does not include a vent port 256, 610, 612 or associated vent channel 258, 614. As previously described, the spool valve 800 comprises a spool 801 slidably disposed within a spool valve bore 803. The spool valve bore 803 is operably connected to and in fluid communication with a CDA deactivator controller via a first hydraulic passageway 802, a second hydraulic passageway (i.e., intake hydraulic fluid manifold) 804, and an engine brake controller via a control input 806, as shown. However, in this case, the first hydraulic passageway 802 and the second hydraulic passageway 804 are offset from one another by a distance O, as shown. Additionally, spool valve bore 803 is in fluid communication with a vent passage 807 which may be open to atmospheric pressure, for example.

[0037] The annular port 810 is configured such that when hydraulic fluid is not applied to the control input 806 of the spool valve 800, i.e., when the spool valve 800 is in its first or default position under the bias applied by the spool valve spring 808, as shown in FIG. 8 , the annular port 810 is wide enough to allow fluid communication between the first hydraulic passageway 802 and the second hydraulic passageway 804 despite the offset therebetween. On the other hand, when hydraulic fluid is applied to the spool valve 800 via the control input 806, i.e., when the spool valve 800 is in the second or actuated position as shown in FIG. 9 , the first passageway 802 is sealed by the land portion 812 of the spool 801. However, the annular port 810 remains aligned with the second fluid passageway 804 and also with the vent passageway 807. The fluid communication between the second hydraulic passage 804 and the vent passage 803 provided by the annular port 810 allows the hydraulic fluid in the second passage (i.e., intake hydraulic fluid manifold) 804 to be vented.

[0038] While various embodiments according to the present disclosure have been described in conjunction with specific implementations thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the present invention described herein are intended to be illustrative only, and not limiting, provided that variations thereof come within the scope of the appended claims and their equivalents.

Claims

1. 1. A system for controlling valve movement to facilitate cylinder deactivation and 1.5 stroke engine braking operation in an internal combustion engine having at least one cylinder, each cylinder including at least one intake valve and corresponding hydraulically controlled intake deactivation device, at least one exhaust valve and corresponding hydraulically controlled exhaust deactivation device, and a hydraulically controlled engine brake actuator, the system comprising: a cylinder deactivation controller operatively connected to and in fluid communication with the intake deactivation device and the exhaust deactivation device for the at least one cylinder; an engine brake controller operably connected to and in fluid communication with the engine brake actuator for the at least one cylinder; a brake dependent deactivation device controller disposed between the cylinder deactivation controller and the intake deactivation device, the brake dependent deactivation device controller being in fluid communication with the cylinder deactivation controller and the intake deactivation device, and in fluid communication with the engine brake controller via a control input of the brake dependent deactivation device controller; the brake dependent deactivation device controller is configured to, in a first state, allow hydraulic fluid flow in a hydraulic fluid control passage for the intake deactivation device when in a non-1.5-stroke engine braking mode, and is further configured, in a second state, to vent the hydraulic fluid control passage for the intake deactivation device when in a 1.5-stroke engine braking mode, in accordance with hydraulic fluid selectively applied to the control input by the engine brake controller.

2. 10. The system of claim 1, wherein the cylinder deactivator controller and the engine brake controller comprise normally-off solenoids.

3. 2. The system of claim 1, wherein the brake-dependent deactivation device controller comprises a spool valve configured to operate in a first position in which fluid communication is provided between the cylinder deactivation controller and the intake deactivation device, and further configured to operate in a second position in which the intake deactivation device is in fluid communication with a vent passage.

4. The system of claim 3 , wherein the vent passage comprises a central bore formed in the spool valve.

5. the spool valve comprises a spool slidably disposed within a spool valve bore, the spool valve bore in fluid communication with the cylinder deactivator controller via a first hydraulic passage and in fluid communication with the intake deactivator via a second hydraulic passage offset and aligned with the first hydraulic passage, the spool valve bore further in fluid communication with the vent passage; 4. The system of claim 3, wherein the spool, when operated in a first position, provides fluid communication between the first hydraulic passage and the second hydraulic passage and simultaneously blocks the vent passage, and, when operated in a second position, provides fluid communication between the second hydraulic passage and the vent passage and simultaneously blocks the first hydraulic passage.

6. 10. The system of claim 1, wherein the intake and exhaust deactivators comprise normally locked / motion transmitting lost motion components.

7. 7. The system of claim 6, wherein the engine brake actuator comprises a normally unlocked / motion absorbing lost motion component.

8. 2. The system of claim 1, further comprising an engine controller operatively coupled to the cylinder deactivation controller and the engine brake controller, the engine controller operative to activate the cylinder deactivation controller subsequent to activation of the engine brake controller when initiating the 1.5 stroke engine braking mode.

9. 9. The system of claim 8, wherein the engine controller is further operative to activate the cylinder deactivation controller after activation of the engine brake controller when initiating the 1.5 stroke engine braking mode.

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