WO2024152264A1

WO2024152264A1 - Valve train assembly for decompression of engine

Info

Publication number: WO2024152264A1
Application number: PCT/CN2023/072962
Authority: WO
Inventors: Tianpeng Chen; Kai WAN; Chengxiu Huang
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2023-01-18
Filing date: 2023-01-18
Publication date: 2024-07-25
Anticipated expiration: 2025-07-18

Abstract

A valvetrain assembly includes a rocker arm assembly and a coupled slide rail assembly. The slide rail assembly includes a slide rail having a plurality of engagement members and a plurality of actuation pin assemblies, where each of the actuation pin assemblies corresponds to each of the engagement members. Each of the actuation pin assemblies is coupled to a respective rocker arm within the rocker arm assembly, and includes a pin, a first biasing member disposed on a first end of the pin, and a second biasing member disposed on a second end of the pin. The second end engages with an end of each of a corresponding engagement member, and movement of the slide rail in a first direction causes the first end to engage with the respective rocker arm. The second biasing member moves the slide rail in a second direction to disengage the first end.

Description

VALVE TRAIN ASSEMBLY FOR DECOMPRESSION OF ENGINE

TECHNICAL FIELD

The present disclosure relates generally to the field of internal combustion engines including valvetrain assemblies.

BACKGROUND

Generally, valvetrains control operation of intake and exhaust valves in an internal combustion engine, where the intake and exhaust valves respectively control a flow of air (or a flow of air and fuel) into a combustion chamber and a flow of spent exhaust gasses from the combustion chamber. A valvetrain includes a camshaft and rod, which cooperate to actuate a rocker arm that actuates valves of the valvetrain.

Valvetrains may be used in a variety of vehicles, including standard internal combustion engine systems and hybrid engine systems. However, valvetrain movement may cause vibration and vehicle shaking due to frequent starts and stops of an engine, such as in a hybrid vehicle.

SUMMARY

One aspect of the present disclosure relates to a valvetrain assembly for a cylinder in an internal combustion engine. The valvetrain assembly includes a rocker arm assembly and a slide rail assembly coupled to the rocker arm assembly. The slide rail assembly includes a slide rail having a plurality of outwardly extending engagement members and a plurality of actuation pin assemblies disposed along the slide rail. Each of the plurality of actuation pin assemblies corresponds to each of the plurality of engagement members and each of the plurality of actuation pin assemblies is coupled to a respective rocker arm within the rocker arm assembly. Each of the plurality of actuation pin assemblies includes a pin having a first end and a second end, where the second end of the pin is configured to engage with an end of a corresponding engagement member of the plurality of engagement members. Each of the plurality of actuation pin assemblies further includes a first biasing member disposed on the first end of the pin, and a second biasing member disposed on the second end of the pin. Movement of the slide rail in a first direction causes the first end of the pin to engage with the respective rocker arm to decompress the cylinder and compress the first biasing member and the second biasing member drives movement of the slide rail in a second direction to disengage the first end of the pin from the respective rocker arm.

In various embodiments, each of the plurality of actuation pin assemblies includes a housing, where the pin is disposed within the housing. In some embodiments, the housing is coupled to the rocker arm assembly via a support member. In other embodiments, the housing includes a first bore and a second bore adjacent the first bore, where the pin is disposed within the first bore and the second bore. In yet other embodiments, the first bore has a greater diameter than the second bore, where the housing includes a ridge formed at a point where the first bore connects to the second bore. In various embodiments, the first end of the pin is disposed within a bore of the first biasing member and the second end of the pin is disposed within a bore of the second biasing member, the pin includes a flange disposed between the first end and the second end, where the first biasing member is configured to abut the ridge and the flange, and the second biasing member is configured to abut the flange and the end of the engagement member. In some embodiments, the first biasing member has a first stiffness and the second biasing member has a second stiffness, where the second stiffness is greater than the first stiffness. In other embodiments, movement of the slide rail is driven by at least one actuator. In yet other embodiments, the at least one actuator is a solenoid.

Another aspect of the present disclosure relates to a valvetrain assembly for a cylinder in an internal combustion engine. The valvetrain assembly includes a plurality of rocker arms, at least one actuator, a slide rail coupled to the at least one actuator, and a plurality of actuation pin assemblies disposed along the slide rail, where each of the plurality of actuation pin assemblies is coupled to each of the plurality of rocker arms. Each of the plurality of actuation pin assemblies includes a pin having a first end and a second end, where the second end of the pin is configured to engage with an engagement member of the slide rail. Each of the plurality of actuation pin assemblies also includes a first biasing member disposed on the first end of the pin, and a second biasing member disposed on the second end of the pin, where the at least one actuator is configured to displace the slide rail in a first direction such that the first end of the pin engages with the respective rocker arm to decompress the cylinder and compress the first biasing member, and where the first end of the pin is configured to disengage from the respective rocker arm responsive to the slide rail displacing in a second direction opposite the first direction.

In various embodiments, the slide rail is coupled to the at least one actuator via a shaft, where the shaft is rotatably coupled to the slide rail. In some embodiments, the at least one actuator is configured to drive the shaft in the second direction, which causes the slide rail to displace in the first direction. In other embodiments, the at least one actuator is a solenoid. In yet other embodiments, the at least one actuator is configured to operate at a frequency of approximately 10 Hz. In some embodiments, the at least one actuator is configured to operate at a frequency of approximately 20 Hz. In various embodiments, the second biasing member is configured to drive displacement of the slide rail in the second direction. In some embodiments, the at least one actuator includes a second actuator, where the second actuator is configured to drive displacement of the slide rail in the second direction.

Yet another aspect of the present disclosure relates to an internal combustion engine. The internal combustion engine includes a plurality of rocker arms configured to control operation of intake and exhaust valves within a cylinder of the internal combustion engine, an actuator, a slide rail coupled to the actuator, where the actuator is configured to displace the slide rail, and a plurality of actuation pin assemblies disposed along the slide rail, where each of the plurality of actuation pin assemblies is coupled to each of the plurality of rocker arms. Each of the plurality of actuation pin assemblies includes a pin having a first end and a second end, where the second end of the pin is configured to engage with an end of an engagement member of the slide rail. Each of the plurality of actuation pin assemblies further includes a first biasing member disposed on the first end of the pin and a second biasing member disposed on the second end of the pin, where the actuator is configured to displace the slide rail in a first direction such that the first end of the pin engages with the respective rocker arm to decompress the cylinder and compress the first biasing member, and where the first end of the pin is configured to disengage from the respective rocker arm responsive to the slide rail displacing in a second direction opposite the first direction.

In various embodiments, the actuator is configured to displace the slide rail when the internal combustion engine is in an idling state or a shutdown state. In some embodiments, the second end of the pin is received within a recess disposed in the end of the engagement member.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:

FIG. 1 is a perspective view an internal combustion engine having a valvetrain system, according to an example embodiment.

FIG. 2 is a top view of the valvetrain system in an activated configuration, according to an example embodiment.

FIG. 3 is a cross-sectional view of the valvetrain system of FIG. 2 near a rocker lever connection to a slide rail.

FIG. 4 is a top view of the valvetrain system of FIG. 2 in a deactivated configuration, according to an example embodiment.

FIG. 5 is a cross-sectional view of the valvetrain system of FIG. 4 near the rocker lever connection to a slide rail.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate certain example embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

Various embodiments of the present disclosure relates to a valvetrain system that is configured to reduce noise, vibration, and harshness (NVH) within an internal combustion engine. In particular, the present disclosure relates to a valvetrain system that can be configured to reduce vibration during starting and stopping of a commercial hybrid engine.

Referring to FIG. 1, an internal combustion engine 10 is shown, according to an example embodiment. In various embodiments, the internal combustion engine 10 is for a hybrid vehicle. In some embodiments, the internal combustion engine 10 is for a commercial or passenger vehicle. The internal combustion engine 10 includes a crankshaft 15, a camshaft 20, a valvetrain assembly 100, a rocker arm assembly 105, a slide rail assembly 110, and an actuator 125. The crankshaft 15 drives the camshaft 20, which rotates to open and close engine valves of a valvetrain assembly 100 corresponding to a cylinder in the engine 10, which is disposed within a cylinder head 25.

The valvetrain assembly 100 includes a plurality of rocker arms 135, such as a rocker arm assembly 105. The valvetrain assembly 100 further includes a slide rail 120 and a plurality of actuation pin assemblies 130 separately or in a slide rail assembly 110. When the valvetrain assembly 100 includes a plurality of rocker arms 135, the slide rail 120, and the actuation pin assemblies 130, the valvetrain assembly 100 includes at least one actuator 125. When the valvetrain assembly 100 is used in the internal combustion engine 10, the internal combustion engine 10 includes the plurality of rocker arms 135, the slide rail 120, and the actuation pin assemblies 130. Alternatively, the internal combustion engine 10 includes the rocker arm assembly 105 and the slide rail assembly

Referring to FIG. 2, a valvetrain assembly 100 within the internal combustion engine 10 is shown, according to an example embodiment. The valvetrain assembly 100 includes the rocker arm assembly 105 and the slide rail assembly 110, which is coupled to the rocker arm assembly 105. The rocker arm assembly 105 includes a plurality of rocker arms 135. The plurality of rocker arms 135 are configured to control operation of intake and exhaust valves in response to actuation by the coupled camshaft 20 within the internal combustion engine 10. The intake and exhaust valves and the camshaft 20 are disposed within the cylinder head 25 above a combustion chamber within the internal combustion engine 10.

As shown in FIG. 2, the slide rail assembly 110 includes a slide rail 120 and the actuator 125, which is configured to displace the slide rail 120. In various embodiments, the slide rail 120 is coupled to the actuator 125 via a push rod or shaft 115 included within the engine 10. The push rod or shaft 115 can be rotatably coupled to the slide rail 120 at a first end. The push rod or shaft 115 can be further coupled to the actuator 125 (e.g., solenoid actuator) at a second end. The actuator 125 is configured to cyclically actuate the shaft 115 to displace the slide rail 120 in either a first direction 127 or second direction 128. The slide rail 120 is coupled to the rocker arm assembly 105 via a plurality of engagement members 140, which are also included within the valvetrain assembly 100.

Each of the plurality of engagement members 140 are configured to engage with a corresponding plurality of actuation pin assemblies 130 disposed along the slide rail 120 within the engine 10. As shown, each of the engagement members 140 extends outwardly away from the slide rail 120 in a direction substantially perpendicular to a primary longitudinal axis of the slide rail 120. Each of the actuation pin assemblies 130 engages with a respective member 147 of each rocker arm 135. Accordingly, movement of the slide rail 120, as driven by the actuator 125, is transmitted to each of the rocker arms 135 via the actuation pin assemblies 130 and the engagement members 140.

Each actuation pin assembly 130 includes a shaft or pin 170 having a first end 185 and a second end 186, a first biasing member 190 disposed on the first end 185 of the pin 170, and a second biasing member 195 disposed on the second end 186 of the pin 170. The second end 186 of the pin 170 is configured to engage with an end of a corresponding engagement member 140.

As shown in FIGS. 2 and 3, each of the actuation pin assemblies 130 includes a housing 145, which are connected to the rocker arm assembly 105 via one or more support members 150 (e.g., cover, bracket) and fasteners 160 (e.g., screws, bolts, clips, etc. ) . As shown in FIG. 3, which illustrates a cross-sectional view of an actuation pin assembly 130 taken along a longitudinal axis of the engagement member 140, the housing 145 includes a first internal recess or bore 165 and a second internal recess or bore 167. In various embodiments, the second internal bore 167 is disposed adjacent the bore 165. As shown in FIG. 3, a width or diameter of the first bore 165 is greater than a diameter of the second bore 167 such that a ridge 169 is formed within the housing 145 where the first bore 165 connects to the second bore 167.

Each of the plurality of actuation pin assemblies includes a shaft or pin 170 (e.g., lashing pin) included within the housing 145. The pin 170 is configured to articulate within the first bore 165 and the second bore 167. In various embodiments, movement of the pin 170 is limited by the length and width of the first bore 165 and second bore 167. A first end 185 of the pin 170 slides relative to a pin 180, which is coupled to the member 147 of the rocker arm 135. Accordingly, the pin 170 selectively abuts or compresses the member 147 responsive to movement of the slide rail 120 (as driven by the actuator 125) . The second end 186 of the pin 170 engages with an end of the engagement member 140 such that movement of the engagement member 140 (which corresponds to movement of the slide rail 120) is transmitted to the member 147 of the rocker arm 135 via the pin 170. In various embodiments, the pin 170 abuts an end of the engagement member 140. In other embodiments, the pin 170 is received within a boss, recess or aperture disposed in an end of the engagement member 140. In some embodiments, the pin 170 is coupled to the engagement member 140 (e.g., via one or more fasteners, via a threaded connection, etc. ) .

As shown, the pin 170 includes a radial protrusion or flange 175, which is disposed between the first end 185 of the pin 170 and a second end 186 of the pin 170. A first biasing member, for example in the form of a first spring 190 (e.g., a return spring) is disposed within the first bore 165 such that the first end 185 of the pin 170 fits through a central bore of the spring 190. Similarly, the second end 186 of the pin 170 fits through a central bore of a second biasing member, for example in the form of a second spring 195 (e.g., a driver spring) . Accordingly, as shown in FIG. 5, the first spring 190 abuts the ridge 169 and the flange 175, and the second spring 195 abuts the flange 175 and the engagement member 140 such that each of the first spring 190 and the second spring 195 enacts a force on the flange 175 to bias the pin 170 away from the member 147. In various embodiments, a stiffness of the first spring 190 is less than a stiffness of the second spring 195. In other embodiments, the stiffness of the first spring 190 is greater than a stiffness of the second spring 195. In yet other embodiments, each of the first spring 190 and the second spring 195 has a same or substantially same stiffness.

During operation, the slide rail assembly 110 is configured to alternate between an activation state, which includes a loading phase and an engagement phase, and a deactivation state. In the loading phase of the activation state, the actuator 125 drives the shaft in the second direction 128, which causes the slide rail 120 to be displaced in the first direction 127 (e.g., toward a front of the engine 10) such that activation energy is stored in the first spring 190 (e.g., driver spring) and the pin 170 is disposed to contact the member 147 of the rocker arm 135. In the engagement phase of the activation state, once the member 147 of the rocker arm 135 engages with the pin 170 (i.e., when the rocker arm 135 moves downward from a top position) , the pin 170 decompresses the cylinder (i.e., in the cylinder head 25) . In the absence of decompression of the cylinder (i.e., in the cylinder head 25) , trapped air within the cylinder may not escape, which can lead to increased vibration.

FIGS. 2 and 3 show the slide rail assembly 110 in the activation state. As illustrated, when in the activation state, the first spring 190 is compressed between the ridge 170 and the flange 175 and the second spring 195 is compressed between the flange 175 and the engagement member 140. In various embodiments, an amount of compression of the spring 190 is greater than an amount of compression of the second spring 195. As shown, when in the activation state, the engagement member 140 abuts or is disposed adjacent an end of the housing 145 (i.e., at an end of the first bore 165) .

FIGS. 4 and 5 show the slide rail assembly 110 in the deactivation state. In the deactivation state, the actuator 125 is configured to reset such that the slide rail 120 is displaced in the direction 128 and returned to a starting position in which the pin 170 does not engage with the member 147 of the rocker arm 135. The slide rail 120 is driven to return to the starting position by the spring 195, which exerts a force on the engagement member 140 and the flange 175 (together with force exerted by the spring 190 on the ridge 169 and the flange 175) to separate the pin 170 from the member 147. As shown in FIGS. 4 and 5, when in the deactivation state, the engagement members 140 of the slide rail 120 are separated from the housing 145 as spaced by the pin 170 and the second spring 195. In addition, when in the deactivation state, the pin 170 slides relative to the pin 180 such that the first end 185 of the pin 170 is not in contact with the member 147 of the rocker arm 135.

In various embodiments, the actuator 125 is operated at varying frequencies based on an operational state of the engine 10. In some embodiments, the actuator 125 operates at a frequency of approximately 10 Hz when the engine 10 is at an idling speed. In other embodiments, the actuator 125 operates at a frequency of approximately 20 Hz when the engine 10 is at a running (e.g., driving) speed. In yet other embodiments, the operation frequency of the actuator 125 is variable based on a driving force needed to displace the shaft 115 (and the slide rail 120) .

In various embodiments, the actuator 125 only operates during idling and shutdown of the engine 10 such that the slide rail assembly 110 consequently only operates during idling and shutdown of the engine 10. In some embodiments, the slide rail assembly 110 includes more than one actuator 125. For example, in some embodiments, the slide rail assembly 110 includes two actuators 125. In some embodiments, a first actuator is configured to activate the slide rail assembly 110 (such that the slide rail 120 moves in a first direction where the pin 170 engages with the member 147) and a second actuator is configured to deactivate the slide rail assembly 110 (such that the slide rail 120 moves in a second direction where the pin 170 disengages with the member 147) .

When the slide rail assembly 110 cyclically engages and disengages with the rocker arm assembly 105 in the respective activation and deactivation states, the net effect is to shake the engine 10 regularly, which may release trapped air and reduces vibration. In various embodiments, the slide rail assembly 110 is retrofitted to the rocker arm assembly 105 since the slide rail assembly 110 is coupled to rocker arm assembly 105 separately from the camshaft 20. Such an arrangement allows the slide rail 120 and related components to move independently from the rocker arms 135. Accordingly, implementation of the slide rail assembly 110 does not require consideration of valve timing as reciprocating motion of each of the rocker arms 135 within the rocker arm assembly 105 is driven by the camshaft 20 (and valve springs) and the slide rail assembly 110 is driven by the actuator 125. Furthermore, the location of the actuation pin assemblies 130 allows for the pin 170 to be positioned in a manner that allows each of the valves in the engine 10 to remain open during starting and stopping of the engine 10.

Notwithstanding the embodiments described above in reference to FIGS. 1–5, various modifications and inclusions to those embodiments are contemplated and considered within the scope of the present disclosure.

As utilized herein with respect to numerical ranges, the terms “approximately, ” “about, ” “substantially, ” and similar terms generally mean +/-10%of the disclosed values, unless specified otherwise. As utilized herein with respect to structural features (e.g., to describe shape, size, orientation, direction, relative position, etc. ) , the terms “approximately, ” “about, ” “substantially, ” and similar terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

It should be noted that the term “example” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples) .

The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable) . Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled) , the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member) , resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

References herein to the positions of elements (e.g., “top, ” “bottom, ” “above, ” “below” ) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other example embodiments, and that such variations are intended to be encompassed by the present disclosure.

The hardware and data processing components used to implement the various processes, operations, illustrative logics, logical blocks, modules and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose single-or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) , or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, particular processes and methods may be performed by circuitry that is specific to a given function. The memory (e.g., memory, memory unit, storage device) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present disclosure. The memory may be or include volatile memory or non-volatile memory, and may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. According to an example embodiment, the memory is communicably connected to the processor via a processing circuit and includes computer code for executing (e.g., by the processing circuit or the processor) the one or more processes described herein.

The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above.

It is important to note that any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.

Claims

A valvetrain assembly for a cylinder in an internal combustion engine, the valvetrain assembly comprising:

a rocker arm assembly; and

a slide rail assembly coupled to the rocker arm assembly, the slide rail assembly comprising:

a slide rail comprising a plurality of outwardly extending engagement members; and

a plurality of actuation pin assemblies disposed along the slide rail, each of the plurality of actuation pin assemblies corresponding to each of the plurality of engagement members and each of the plurality of actuation pin assemblies being coupled to a respective rocker arm within the rocker arm assembly;

wherein each of the plurality of actuation pin assemblies comprises:

a pin having a first end and a second end, the second end of the pin being configured to engage with an end of a corresponding engagement member of the plurality of engagement members;

a first biasing member disposed on the first end of the pin; and

a second biasing member disposed on the second end of the pin;

wherein movement of the slide rail in a first direction causes the first end of the pin to engage with the respective rocker arm to decompress the cylinder and compress the first biasing member; and

wherein the second biasing member drives movement of the slide rail in a second direction to disengage the first end of the pin from the respective rocker arm.
The valvetrain assembly of claim 1, wherein each of the plurality of actuation pin assemblies comprises a housing, and wherein the pin is disposed within the housing.
The valvetrain assembly of claim 2, wherein the housing is coupled to the rocker arm assembly via a support member.
The valvetrain assembly of claim 2 or claim 3, wherein the housing comprises a first bore and a second bore adjacent the first bore, and wherein the pin is disposed within the first bore and the second bore.
The valvetrain assembly of claim 4, wherein the first bore has a greater diameter than the second bore, and wherein the housing includes a ridge formed at a point where the first bore connects to the second bore.
The valvetrain assembly of claim 5, wherein:

the first end of the pin is disposed within a bore of the first biasing member and the second end of the pin is disposed within a bore of the second biasing member; and

the pin comprises a flange disposed between the first end and the second end, the first biasing member configured to abut the ridge and the flange and the second biasing member configured to abut the flange and the end of the engagement member.
The valvetrain assembly of any of claims 1-3, 5-6, wherein the first biasing member has a first stiffness and the second biasing member has a second stiffness, the second stiffness being greater than the first stiffness.
The valvetrain assembly of any of claims 1-3, 5-6, wherein movement of the slide rail is driven by at least one actuator.
The valvetrain assembly of claim 8, wherein the at least one actuator is a solenoid.
A valvetrain assembly for a cylinder in an internal combustion engine, the valvetrain assembly comprising:

a plurality of rocker arms;

at least one actuator;

a slide rail coupled to the at least one actuator; and

a plurality of actuation pin assemblies disposed along the slide rail, each of the plurality of actuation pin assemblies being coupled to each of the plurality of rocker arms, wherein each of the plurality of actuation pin assemblies comprises:

a pin having a first end and a second end, the second end of the pin being configured to engage with an engagement member of the slide rail;

a first biasing member disposed on the first end of the pin; and

a second biasing member disposed on the second end of the pin;

wherein the at least one actuator is configured to displace the slide rail in a first direction such that the first end of the pin engages with the respective rocker arm to decompress the cylinder and compress the first biasing member; and

wherein the first end of the pin is configured to disengage from the respective rocker arm responsive to the slide rail displacing in a second direction opposite the first direction.
The valvetrain assembly of claim 10, wherein the slide rail is coupled to the at least one actuator via a shaft, wherein the shaft is rotatably coupled to the slide rail.
The valvetrain assembly of claim 11, wherein the at least one actuator is configured to drive the shaft in the second direction, which causes the slide rail to displace in the first direction.
The valvetrain assembly of any of claims 10-12, wherein the at least one actuator is a solenoid.
The valvetrain assembly of any of claims 10-12, wherein the at least one actuator is configured to operate at a frequency of approximately 10 Hz.
The valvetrain assembly of any of claims 10-12, wherein the at least one actuator is configured to operate at a frequency of approximately 20 Hz.
The valvetrain assembly of any of claims 10-12, wherein the second biasing member is configured to drive displacement of the slide rail in the second direction.
The valvetrain assembly of any of claims 10-12, wherein the at least one actuator comprises a second actuator, the second actuator configured to drive displacement of the slide rail in the second direction.
An internal combustion engine comprising:

a plurality of rocker arms configured to control operation of intake and exhaust valves within a cylinder of the internal combustion engine;

an actuator;

a slide rail coupled to the actuator, wherein the actuator is configured to displace the slide rail; and

a plurality of actuation pin assemblies disposed along the slide rail, each of the plurality of actuation pin assemblies being coupled to each of the plurality of rocker arms, wherein each of the plurality of actuation pin assemblies comprises:

a pin having a first end and a second end, the second end of the pin being configured to engage with an end of an engagement member of the slide rail;

a first biasing member disposed on the first end of the pin; and

a second biasing member disposed on the second end of the pin;

wherein the actuator is configured to displace the slide rail in a first direction such that the first end of the pin engages with the respective rocker arm to decompress the cylinder and compress the first biasing member; and

wherein the first end of the pin is configured to disengage from the respective rocker arm responsive to the slide rail displacing in a second direction opposite the first direction.
The internal combustion engine of claim 18, wherein the actuator is configured to displace the slide rail when the internal combustion engine is in an idling state or a shutdown state.
The internal combustion engine of claim 18 or claim 19, wherein the second end of the pin is received within a recess disposed in the end of the engagement member.