This disclosure generally relates to a valvetrain system, and more particularly to a swing bridge.
Various valve system designs have been produced in the past for use in connection with internal combustion engines for the purpose of controlling valve actuation such as for main exhaust event. Generally, in a typical valvetrain, a rocker arm system is coupled on one side to a camshaft and on the other side to a number of engine valves via a valve bridge in a way for delivering actuation motion from the camshaft to downstream valves in synchronization. In some scenarios, it may be desirable to provide auxiliary functionality, such as compression engine braking, in addition to the main lift event such that a chosen valve may be separately controlled. To achieve this, a switchable system is often employed, which can be selectively translated between a retracted and extended position, the retracted position disabling actuation of the associated valve by a corresponding dedicated rocker arm and the extended position enabling actuation of the valve. Correspondingly, the valve bridge may also be equipped with a motion-transmitting mechanism that serves to independently actuate the selected valve without affecting the others. However, current designs typically utilize a sliding component that moves up and down within the valve bridge, which introduces force balancing issues and occupies relatively large packaging space.
Consequently, there is a need to provide a solution that not only demands less space but also offers improved system dynamics.
This disclosure presents a swing bridge for use with a rocker arm assembly that is able to swing on demand to actuate at least one selected valve separately from a totality of valves in order to achieve auxiliary valve function. By employing a swing mechanism that may transfer motion from a rocker arm to an associated valve and at the same time move relative to the swing bridge, the system disclosed herein may achieve better force and/or motion transmission, reduce undesired wear in various valvetrain components, and improve dynamic behavior of the overall assembly. Moreover, the embodiments according to this disclosure may offer packaging advantages and are less demanding in terms of spatial requirement.
In one embodiment, a swing bridge for a rocker arm assembly is provided. The swing bridge is configured to be selectively actuated by a first rocker arm or a second rocker arm and span a first valve and a second valve. Specifically, the swing bridge comprises a bridge body including a through opening and a bore intersecting the through opening, and a swing mechanism configured to connect between the first rocker arm and the first valve. The swing mechanism comprises a swing pin configured to swing in the through opening and a rotary cylinder configured to support the swing pin and rotate in the bore. Moreover, the swing bridge is further configured to swing angularly upon actuation by the first rocker arm so as to actuate the first valve without actuating the second valve, and actuate both the first valve and the second valve upon actuation by the second rocker arm.
In particular embodiments, the through opening is arranged along a vertical direction.
In particular embodiments, the bore is arranged perpendicular to the through opening.
In particular embodiments, the rotary cylinder is secured axially by the swing pin.
In particular embodiments, a major axis of the rotary cylinder is perpendicular to a major axis of the swing pin.
In particular embodiments, a clearance is defined between the swing pin and the through opening so as to allow swinging of the swing pin inside the through opening.
In particular embodiments, the swing pin is generally cylindrical in structure.
In particular embodiments, the swing mechanism further comprises a first valve seat for contacting at least a portion of the first valve, and the bridge body comprises a second valve seat for contacting at least a portion of the second valve.
In particular embodiments, the swing mechanism further comprises a first contact area for contacting the first rocker arm, and the bridge body comprises a second contact area for contacting the second rocker arm.
In particular embodiments, the first contact area is located on a top surface of the swing pin.
In one embodiment, a swing bridge for a rocker arm assembly is provided. The swing bridge is configured to be selectively actuated by a first rocker arm or a second rocker arm and span a first valve and a second valve. Specifically, the swing bridge comprises a bridge body including a through opening and a bore intersecting the through opening, and a swing mechanism configured to connect between the first rocker arm and the first valve. The swing mechanism comprises a swing pin configured to swing in the through opening and including an insert at a lower end of the swing pin, and a rotary cylinder configured to rotate in the bore and including a slot at an upper surface of the rotary cylinder so as to mate with the insert. Moreover, the swing bridge is further configured to swing angularly upon actuation by the first rocker arm so as to actuate the first valve without actuating the second valve, and actuate both the first valve and the second valve upon actuation by the second rocker arm.
In particular embodiments, the rotary cylinder further comprises a valve seat at a lower surface of the rotary cylinder for contacting at least a portion of the first valve.
In particular embodiments, the swing pin axially engages with the rotary cylinder via the insert and the slot.
In particular embodiments, a major axis of the rotary cylinder is perpendicular to a major axis of the swing pin.
In particular embodiments, a clearance is defined between the swing pin and the through opening so as to allow swinging of the swing pin inside the through opening.
In one embodiment, a swing bridge for a rocker arm assembly is provided. The swing bridge is configured to be selectively actuated by a first rocker arm or a second rocker arm and span a first valve and a second valve. Specifically, the swing bridge comprises a bridge body including a through opening and a bore intersecting the through opening, and a swing mechanism configured to connect between the first rocker arm and the first valve. The swing mechanism comprises a swing pin configured to swing in the through opening and including a through hole extending perpendicular to a major axis of the swing pin, and a rotary cylinder configured to be fitted into the bore and the through hole in a rotatable manner. Moreover, the swing bridge is further configured to swing angularly upon actuation by the first rocker arm so as to actuate the first valve without actuating the second valve, and actuate both the first valve and the second valve upon actuation by the second rocker arm.
In particular embodiments, the through hole is positioned to be aligned with the bore.
In particular embodiments, the rotary cylinder extends through the bore and the through hole so as to axially support the swing pin relative to the bridge body.
In particular embodiments, the swing pin further comprises a valve seat at a lower end of the swing pin for contacting at least a portion of the first valve.
In particular embodiments, a clearance is defined between the swing pin and the through opening so as to allow swinging of the swing pin inside the through opening.
Embodiments in accordance with this disclosure will now be described by reference to the accompanying drawings, in which:
Reference will now be made in detail to the examples which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Directional references such as “up”, “down”, “right”, and “left” are for ease of reference to the figures and not intended to limit the scope of this disclosure.
While particular embodiments of this disclosure may be set forth in the context of rocker arms for operating exhaust valves in an engine braking system, for example, such as for use in 1.5 or 2 stroke compression braking, it will nevertheless be appreciated by one of skill in the art that the disclosure is not limited to such an application. Various embodiments in accordance with this disclosure may be equally or similarly applicable to other types of systems in the valvetrain assembly. For example, embodiments of this disclosure may be used in connection with an intake rocker arm system, an extended valve closing system, an early valve opening system, or other suitable valvetrain systems as familiar to a skilled person in the art.
With continued reference to
In particular embodiments, it may be desirable to configure the secondary rocker arm 106 to be selectively switchable such that one can choose whether the secondary lift cam 120 can actuate the associated engine valve 108 or not. That is, the secondary rocker arm 106 may transfer between a main mode (i.e., the valve end 124 is spaced from contact relative to the swing bridge 102, thus the associated engine valve 108 remains unactuated regardless of rotation of the secondary rocker arm 106) and an auxiliary mode (i.e., the valve end 124 engages the swing bridge 102 via the swing mechanism 126 as the secondary rocker arm 106 reciprocates, allowing motion to be delivered to the engine valve 108.) To this end, a hydraulic capsule 128 may be provided at the valve end 124 of the secondary rocker arm 106. The hydraulic capsule 128 may be controlled hydraulically by pressurized fluid supplied via a fluid circuit running through the secondary rocker arm 106 and configured to move between a retracted position and an extended position. In particular embodiments, for example, the hydraulic capsule 128 may be received by a vertical bore arranged in the valve end 124 of the secondary rocker arm 106. During operation, the hydraulic capsule 128 may be actuated on demand to either protrude outwards from the bottom of the valve end 124 to contact the swing mechanism 126 or retract back into the valve end 124 to avoid touching the swing mechanism 126.
As shown in
As further illustrated in
With continued reference to
The design of the hydraulic capsule 128 disclosed herein contrasts those of prior art since the plunger 314 can remain compressed as default by means of the spring 326 when deactivation is needed, thus avoiding any contact between the hydraulic capsule 128 and the swing bridge 102. This can save the system from undesired wearing, reduce the risk of damage to the movable components, and help maintaining proper system dynamics.
Although depicted and described in this particular manner, a person of skill in the art will appreciate that the rocker arm assembly disclosed herein is provided for illustration purposes only, and not intended to limit the scope of this disclosure. Other suitable configurations are also envisioned by this disclosure. For example, certain embodiments in accordance with this disclosure may comprise only some, if not all, of the above-described structures without departing from the scope of this disclosure. Alternatively, other additional features as familiar in the art may be optionally provided and will not be described in exhaustive detail herein.
With continued reference to
As further illustrated, in this example embodiment, the swing pin 502 may generally be cylindrical in structure. Nevertheless, other suitable configurations (such as elongated or the like) are also contemplated for performing the desired functions of this disclosure. In particular embodiments, the swing pin 502 may include at upper end thereof a contact surface for contacting the hydraulic capsule 128 so as to receive actuation motion therefrom. Furthermore, the swing pin 502 may also include an insert 514 (e.g., in the form of a protrusion) extending from a lower end thereof in order to engage with the rotary cylinder 504. Accordingly, upper surface of the rotary cylinder 504 may be provided with a recess or slot 516 that is shaped to mate with the insert 514 and/or the lower end of the swing pin 502 in such a way that the insert 514 and/or the lower end may be snugly fitted into the slot 516 so as to axially secure the rotary cylinder 504. Additionally or alternatively, other suitable connecting or mating structures or methods such as snap fit, interference fit, or the like may be employed for properly securing the swing pin 502 and the rotary cylinder 504 together. Configured in this way, the rotary cylinder 504 may be able to maintain secure engagement with the swing pin 502 at the same time providing support to the swing pin 502.
In the embodiment as shown, lower surface of the rotary cylinder 504 may be configured with a valve seat 604, which may maintain contact with the terminal of the engine valve 108 throughout system operation. As an example and not by way of limitation, the valve seat 604 may include a substantially flat area that rests on top of the valve tip in order to ensure proper contact with the engine valve 108, thereby transmitting actuation movement to the engine valve 108 as needed. Alternatively or additionally, while not shown, optional retention features such as clips or the like may be provided at the valve seat 604 to provide for additional degree of securement. Of course, other suitable surface structures such as curved surface area as familiar to those skilled in the art are also envisioned by this disclosure for performing the intended function of engaging the engine valve.
Operation of the swing bridge 102 in accordance with this disclosure will be explained with reference to
Referring to
In addition, when in drive mode, the secondary rocker arm 106 may be on base circle or deactivated. Alternatively or additionally, the hydraulic capsule 128 may be retracted in order to refrain from contacting the swing bridge 102 even if the secondary rocker arm 106 rotates such that the swing bridge 102, specifically the swing mechanism 126, receives zero actuation motion from the secondary rocker arm 106.
Referring to
In this embodiment as shown, the swing pin 1102 may be elongated and include a through hole 1114 that extends perpendicular to the major axis 1106 and is configured to receive the rotary cylinder 1104 in a rotatable manner. In this configuration, during assembly, the swing pin 1102 may first be inserted into the through opening 1110 to a position where the through hole 1114 is aligned with the bore 1112. Thereafter, the rotary cylinder 1104 may be fitted into the bore 1112 and through the through hole 1114 in order to support the swing pin 1102 relative to the main body 1004.
In addition, as further illustrated, the swing pin 1102 may also include at upper end thereof a contact surface 1116 for contacting the hydraulic capsule 128 so as to receive actuation motion. As an example and not by way of limitation, the contact surface 1116 may be formed as a platform that extends upwards from the upper end of the swing pin 1102. Alternatively, other possible surface structures may be provided for transmitting motion as needed. In the embodiment as shown, the swing pin 1102 additionally includes a valve seat 1202 disposed at a lower end thereof. For example, the valve seat 1202 may be a circular recess or other suitable structures for engaging the terminal end of the engine valve 108 in a motion-conveying manner. Similarly, the second valve side 1008 may include a valve seat 1204 configured as an elongated pocket or cutout so as to rest on top of the terminal end of the engine valve 110 and maintain contact throughout operation. While depicted in this way, it will be appreciated that the valve seat 1202 and/or 1204 may be structured differently for coupling to the engine valves.
Various embodiments of this disclosure may advantageously offer better packaging and is less demanding with regard to spatial requirement as they achieve a more compact structure. Moreover, the embodiments disclosed herein facilitate better control of motion and/or force transmission and overall system dynamics. It will also be understood that one or more other advantages may be readily apparent to one skilled in the art in view of the figures, descriptions, and claims of this disclosure.
Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.
The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although this disclosure describes and illustrates respective embodiments herein as including particular components, elements, feature, functions, operations, or steps, any of these embodiments may include any combination or permutation of any of the components, elements, features, functions, operations, or steps described or illustrated anywhere herein that a person having ordinary skill in the art would comprehend. Furthermore, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Additionally, although this disclosure describes or illustrates particular embodiments as providing particular advantages, particular embodiments may provide none, some, or all of these advantages.
This disclosure is based on and claims the benefit of U.S. Provisional Application No. 63/394,999, entitled “Swing bridge,” filed on 4 Aug. 2022, and U.S. Provisional Application No. 63/387,025, entitled “Swing bridge with hydraulic capsule in dedicated rocker arm for engine brake,” filed on 12 Dec. 2022, each of which is incorporated by reference herein in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
8851048 | Meistrick | Oct 2014 | B2 |
20180003088 | Nielsen | Jan 2018 | A1 |
20200182098 | Mccarthy | Jun 2020 | A1 |
20210324769 | Gron | Oct 2021 | A1 |
20230016116 | Lahr | Jan 2023 | A1 |
20240044265 | Císar | Feb 2024 | A1 |
Number | Date | Country |
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117514405 | Feb 2024 | CN |
102021000982 | Aug 2022 | DE |
WO 2023025565 | Mar 2023 | WO |
WO 2023247069 | Dec 2023 | WO |
WO-2024094323 | May 2024 | WO |
Number | Date | Country | |
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20240044266 A1 | Feb 2024 | US |
Number | Date | Country | |
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63387025 | Dec 2022 | US | |
63394999 | Aug 2022 | US |