Valve bridge

Abstract

A valve bridge for a rocker arm assembly is provided that includes a first end, a second end, and a top surface connecting a bridge body portion of the first end and the second end. The top surface is configured to engage a first rocker arm. A recess is arranged at the top of the first end. The recess has an at least partially pinnacle shape and is configured to engage with the second rocker arm. A first valve seat is disposed at the bottom of the first end, and the first valve seat includes a curved bottom surface for engaging a first valve. A second valve seat for engaging a second valve is arranged at the bottom of the second end.

Description

[0001] Cross - reference to Related Applications

[0002] This disclosure claims the benefit of U.S. Provisional Application No. 63 / 382,470, filed on November 4, 2022, entitled "Valve Bridge for Engine Braking", the entire content of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to a valve train system, and more particularly, to a valve bridge for use with a rocker arm assembly configured with an engine braking function. Background Art

[0004] Internal combustion engines typically use mechanical, electrical, or electro - hydraulic valve actuation systems to actuate engine valves. These systems may include a combination of a camshaft, rocker arms, and various motion - transmitting mechanisms driven by the rotation of the engine's crankshaft. The timing of valve actuation may be determined by the size and position of the lobes on the camshaft, the configuration of the rocker arms, etc. Summary of the Invention

[0005] This disclosure provides a valve bridge for a rocker arm system that can individually actuate selected valves, i.e., actuate the selected valves without affecting other valves. By employing uniquely shaped features to engage with the rocker arms and engine valves, the valve bridge according to the present disclosure provides better motion and force transmission, maintains more reliable contact and engagement, and optimizes the overall kinematic behavior of the system. For example, the contact areas of the valve bridge with the rocker arms and engine valves are respectively designed to be more ergonomic and streamlined, thereby reducing contact stress and friction. In addition, the structure of the valve bridge is simplified, making the operation and production processes simpler and more cost - effective.

[0006] In one embodiment, a valve bridge for a rocker arm assembly is provided. The valve bridge includes a first end, a second end opposite the first end, and a top surface of a bridge body portion connecting the first end and the second end. The top surface of the bridge body portion is configured to engage with a first rocker arm. A first recess is disposed at the top of the first end. The first recess has a shape that is at least partially pointed at the top and is configured to engage with a second rocker arm. A first valve seat is disposed at the bottom of the first end, and the first valve seat includes a curved bottom surface for engaging a first valve. A second valve seat for engaging a second valve is disposed at the bottom of the second end. Specifically, the valve bridge is configured to translate vertically when actuated by the first rocker arm, thereby actuating both the first valve and the second valve, or to tilt at an angle when actuated by the second rocker arm, thereby actuating the first valve without actuating the second valve.

[0007] In a specific embodiment, the engagement between the first recess and the second rocker arm forms a circular contact line. In a specific embodiment, the first valve seat is a passage. In a specific embodiment, the curved bottom surface of the first valve seat is S-shaped. In a specific embodiment, the curved bottom surface of the first valve seat allows the first valve to move laterally relative to the valve bridge. In a specific embodiment, the second valve seat includes a second recess. In a specific embodiment, the inner diameter of the second valve seat is greater than the outer diameter of the end of the second valve. In a specific embodiment, the second end includes a horizontal through-hole and a kinematic columnar body rotatably inserted into the horizontal through-hole. In a specific embodiment, the kinematic columnar body engages the second valve, and when the valve bridge tilts, the kinematic columnar body maintains surface contact with the second valve. In a specific embodiment, the top surface includes a guiding structure for guiding the movement of the valve bridge relative to the first rocker arm.

[0008] In one embodiment, a valve bridge for a rocker arm assembly is provided. The valve bridge includes a first end, a second end opposite the first end, and a top surface of a bridge body portion connecting the first end and the second end. The top surface of the bridge body portion is configured to engage a first rocker arm. A protrusion is disposed at the top of the first end, and the tip of the protrusion has a spire shape for engaging a second rocker arm. A first valve seat is disposed at the bottom of the first end, and the first valve seat includes a curved bottom surface for engaging a first valve. A second valve seat is disposed at the bottom of the second end for engaging a second valve. Specifically, the valve bridge is configured to translate vertically when actuated by the first rocker arm, thereby actuating both the first valve and the second valve, or to tilt at an angle when actuated by the second rocker arm, thereby actuating the first valve without actuating the second valve.

[0009] In a specific embodiment, the engagement between the protrusion and the second rocker arm forms a circular contact line. In a specific embodiment, the protrusion is removably received by a recess disposed at the top of the first end. In a specific embodiment, the curved bottom surface of the first valve seat is S-shaped. In a specific embodiment, the curved bottom surface of the first valve seat allows the first valve to move laterally relative to the valve bridge.

[0010] In one embodiment, a rocker arm assembly is provided that includes a first rocker arm and a second rocker arm, a first valve and a second valve, and a valve bridge configured to be selectively actuated by the first rocker arm or the second rocker arm. The valve bridge includes a first end, a second end opposite the first end, and a top surface of a bridge body portion connecting the first end and the second end. The top surface of the bridge body portion is configured to engage the first rocker arm. A recess is disposed at the top of the first end. The recess has at least a partially spire-shaped configuration and is configured to engage a spherical end of the second rocker arm. A first valve seat is disposed at the bottom of the first end and includes a curved bottom surface for engaging the first valve. A second valve seat is disposed at the bottom of the second end for engaging the second valve. Specifically, the valve bridge is configured to translate vertically when actuated by the first rocker arm to thereby actuate both the first valve and the second valve, or to tilt at an angle when actuated by the second rocker arm to thereby actuate the first valve without actuating the second valve.

[0011] In a specific embodiment, the first rocker arm is an exhaust rocker arm and the second rocker arm is an engine braking rocker arm. In a specific embodiment, the engagement between the recess and the spherical end of the second rocker arm forms a circular contact line. In a specific embodiment, the second end includes a horizontal through-hole and a kinematic column rotatably inserted into the horizontal through-hole. In a specific embodiment, the top surface includes a guiding structure for guiding the movement of the valve bridge relative to the first rocker arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Embodiments in accordance with the present disclosure will now be described with reference to the drawings, in which:

[0013] Figures 1A to 1B different examples of a valve mechanism assembly in accordance with the present disclosure are shown;

[0014] Figure 2 a first embodiment of a valve bridge for a rocker arm assembly in accordance with the present disclosure is shown;

[0015] Figures 3A to 3B a perspective view of the valve bridge shown from the top Figure 2 is shown;

[0016] Figures 4A to 4B a perspective view of the valve bridge shown from the bottom Figure 2 is shown;

[0017] Figures 5A to 5B a valve bridge in operation when the rocker arm assembly is in a drive mode is shown;

[0018] Figures 6A to 6B a valve bridge in operation when the rocker arm assembly is in an engine braking mode is shown;

[0019] Figures 7 to 8Shows a second embodiment of a valve bridge for a rocker arm assembly according to the present disclosure;

[0020] Figures 9 to 10 Shows a third embodiment of a valve bridge for a rocker arm assembly according to the present disclosure; and

[0021] Figures 11 to 12 Shows a fourth embodiment of a valve bridge for a rocker arm assembly according to the present disclosure. Detailed Description

[0022] Reference will now be made in detail to the examples illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. Directional references such as "upward", "downward", "rightward", and "leftward" are for ease of reference to the drawings and are not intended to limit the scope of the present disclosure.

[0023] The valve bridge can be operatively coupled to the rocker arm and the engine valve to convert the rotation of the rocker arm into the movement of the valve, thereby driving the valve to open under control. It is necessary to optimize the design of the valve bridge to better control valve actuation with a reliable and simplified structure. In the past, various valve system designs have been produced for use in combination with internal combustion engines and for controlling valve actuation (such as main exhaust events). Generally, in a typical valve mechanism, the rocker arm system is coupled to the camshaft on one side and to multiple engine valves via a valve bridge on the other side to synchronously transfer the actuation movement from the camshaft to the downstream valves. In some cases, in addition to the main lift event, it may also be necessary to provide auxiliary functions such as compression engine braking so that selected valves can be controlled individually. To achieve this, a switchable system is typically employed, which can be selectively translated between a retracted position that prevents the corresponding rocker arm from actuating the associated valve and an extended position that allows the valve to be actuated. Accordingly, the valve bridge can also be equipped with a motion transfer mechanism for independently actuating selected valves without affecting other valves. However, current designs typically utilize complex moving parts (such as sliding parts that move up and down within the valve bridge), which can cause force balance problems, occupy a large packaging space, and increase production costs and material costs. Therefore, a solution is needed that is not only cost-effective, easy to manufacture and use, but also provides the required system dynamics characteristics.

[0024] The embodiments disclosed herein provide a valve bridge that solves the above problems. The valve bridge can be rotated as needed so that the selected valve is actuated without affecting the other valve. By using features of unique shapes to engage with the rocker arms and engine valves, the valve bridge according to the present disclosure provides better transmission of motion and force, maintains more reliable contact and engagement, and optimizes the overall kinematic behavior of the system. In addition, the structure of the valve bridge is simplified, thereby reducing the manufacturing cost and improving the convenience of operation.

[0025] First refer to Figures 1A to 1B , which partially shows a valve mechanism assembly constructed according to an example of the present disclosure, and the valve mechanism assembly is generally denoted by reference numeral 10 in the drawings. In a specific embodiment, the valve mechanism assembly 10 may be configured with auxiliary functions such as engine braking, and is shown configured for a three-cylinder bank portion of a six-cylinder engine. Although described as such, it should be understood that the present disclosure is not limited thereto. In this regard, the present disclosure can be used for any valve mechanism assembly with auxiliary functions.

[0026] In a specific embodiment, the valve mechanism assembly 10 may be supported by a valve mechanism bracket 12, and each cylinder may include two rocker arms. Specifically, in a specific embodiment, each cylinder may include an intake rocker arm assembly 14, an exhaust rocker arm assembly 16, and an engine braking rocker arm assembly 18. By way of example and not limitation, as Figure 1A shown in, the exhaust rocker arm assembly 16 and the engine braking rocker arm assembly 18 may be combined into a single rocker arm body and are collectively referred to as a combined exhaust and engine braking rocker arm assembly 20, which cooperate with each other to control the opening or closing of the exhaust valve. In this case, two switchable systems (e.g., capsules, etc.) may be employed to control the exhaust operation and the engine braking operation respectively. As another example and not limitation, as Figure 1B shown in, the exhaust rocker arm assembly 16 and the engine braking rocker arm assembly 18 may be separate components and may act on the valve bridge independently of each other. In a specific embodiment, the intake rocker arm assembly 14 may be configured to control the movement of the intake valve in a drive mode. The exhaust rocker arm assembly 16 may be configured to control the movement of the exhaust valve in a drive mode. The engine braking rocker arm assembly 18 may be configured to act on one of the two exhaust valves (such as an engine braking lift of 4 mm) in an engine braking mode, as will be described herein. In a specific embodiment, each of the intake rocker arm assembly 14, the exhaust rocker arm assembly 16, and the engine braking rocker arm assembly 18 may be a mechanical, electrical, electro-hydraulic, or other suitable valve actuation system.

[0027] Continue to refer to Figure 1A, in a specific embodiment, the rocker shaft 22 is received by the valve mechanism bracket 12 and supports the rotation of the combined exhaust and engine braking rocker assembly 20. As described in more detail herein, the rocker shaft 22 can deliver a control fluid (e.g., oil) to the rocker assemblies 16, 18 during operation. A camshaft (not shown) can include a lift profile or cam lobe configured to rotate the rocker assemblies 16, 18 to actuate the first exhaust valve 26 and the second exhaust valve 28.

[0028] In a specific embodiment, the combined rocker assembly 20 can generally include a rocker body 40, a shaft 42, and a roller 44. The rocker body 40 can include an exhaust rocker portion 46 and an engine braking arm portion 48. The rocker body 40 can be rotatably mounted to the rocker shaft 22 and includes a pair of flanges 50 for receiving the shaft 42 such that the roller 44 on the shaft 42 is at least partially located between the flanges 50. The roller 44 can be configured to be engaged by an exhaust lift lobe or an engine braking lobe of the camshaft. This engagement of the roller 44 causes the combined rocker assembly 20 to rotate according to the cam profile of the camshaft, thereby actuating one or more associated valves as needed. Alternatively, in other embodiments, the combined rocker assembly 20 can include other suitable motion transfer features, such as a push rod operatively coupled between the rocker body 40 and the camshaft for transmitting valve actuation motion.

[0029] In a specific embodiment, the exhaust rocker assembly 16 can include an exhaust rocker portion 46 that can, for example, be defined with a hole configured to at least partially receive a hydraulic lash adjuster (HLA) assembly or an exhaust capsule (not visible in Figure 1A ), the hydraulic lash adjuster assembly or exhaust capsule having an elephant foot (E-foot) or a plunger for contacting the valve bridge. By way of example and not limitation, when the roller 44 is engaged by the exhaust lift profile, the exhaust rocker portion 46 and thus the exhaust capsule can rotate downwardly such that the valve bridge moves downwardly, which in turn pushes downwardly the first exhaust valve and the second exhaust valve 26 and 28 associated with a cylinder (not shown) of the engine. Although described as an example in this specific manner, the present disclosure contemplates rocker assemblies with or without an HLA or an exhaust capsule. In this regard, for example, in embodiments where the exhaust rocker portion is not equipped with a capsule, the valve end of the rocker or other suitable means can be employed to act directly or indirectly on the valve bridge.

[0030] Although specific embodiments of the present disclosure may be described in the context of a rocker arm for operating an exhaust valve in an engine braking system, e.g., for 1.5 or 2 stroke compression braking, those skilled in the art will understand that the present disclosure is not limited to such applications. The various embodiments according to the present disclosure may be applicable to other types of systems in a valve train assembly. For example, embodiments of the present disclosure may be used in combination with an intake rocker arm system, a late closing valve system, an early opening valve system, or other suitable valve train systems known to those skilled in the art.

[0031] Figure 2 A perspective view of an exhaust rocker arm assembly 16 and an engine braking rocker arm assembly 18 is shown, with a valve bridge 100 and first and second exhaust valves 26, 28 installed in place. As shown, the exhaust rocker arm assembly 16 and the engine braking rocker arm assembly 18 may each include a capsule assembly 102. For example, the capsule assembly 102 may be integrated into or coupled to each of the exhaust rocker arm assembly 16 and the engine braking rocker arm assembly 18 and may be configured to transfer force or motion to a downstream component, such as the valve bridge 100. In a particular embodiment, each capsule assembly 102 may include a capsule operable to contact the valve bridge 100 (as may be apparent from Figure 5A and Figure 6Aas seen in). For example, when the exhaust rocker arm assembly 16 and / or the engine-driven rocker arm assembly 18 are actuated, the corresponding capsule can be controlled to extend and push against the valve bridge 100 to move the valve bridge 100. As shown, the valve bridge 100 can be disposed between both the exhaust rocker arm assembly 16 and the engine-driven rocker arm assembly 18 and the first exhaust valve and the second exhaust valves 26, 28. In a specific embodiment, the valve bridge 100 can be configured to receive the first exhaust valve and the second exhaust valves 26, 28. For example, the tops 104A, 104B of the first exhaust valve and the second exhaust valves 26, 28 can be coupled to the valve bridge 100 (e.g., to the lower side of the valve bridge 100). In this way, the actuating force applied to the valve bridge 100 can be transmitted to the first exhaust valve 26 and / or the second exhaust valve 28, causing the first exhaust valve 26 and / or the second exhaust valve 28 to translate downward in the vertical direction. By way of example and not limitation, during a first operation (e.g., in an exhaust mode), both the first exhaust valve and the second exhaust valves 26, 28 can be acted upon by the applied force and translate downward. As another example and not limitation, during a second operation (e.g., in an engine braking mode), only the first exhaust valve 26 can be acted upon by the applied force and translate downward, while the second exhaust valve 28 remains stationary due to the tilting movement of the valve bridge 100. The specific embodiments described herein provide an improved valve bridge 100 that can apply a force to only the first exhaust valve 26 to translate it, where the second exhaust valve 28 remains unactuated regardless of how the valve bridge 100 moves. Additionally, the valve bridge 100 can be configured with a simple structure, which makes manufacturing easier while providing the required movement transmission.

[0032] Figures 3A to 3B FIG. 4 shows a top perspective view of the valve bridge 100, with some portions of the valve bridge 100 cut away for better viewing, in Figure 3B a specific embodiment, the valve bridge 100 can be configured to span across and be located on top of two exhaust valves (such as Figure 2 the first exhaust valve and the second exhaust valves 26, 28 in) to transmit a force to the exhaust valves. As shown, in a specific embodiment, the body 300 of the valve bridge 100 can include a first end 302, a second end 306 spaced apart from the first end 302, and a top surface 308 that connects the first end 302 and the second end 306. By way of example and not limitation, the first end 302 can be operatively coupled to the end of the first exhaust valve 26, and the second end 306 can be generally opposite the first end 302 and operatively coupled to the end of the second exhaust valve 28. In a specific embodiment, the top surface 308 of the valve bridge 100 can be configured to be coupled or engaged with the exhaust rocker arm assembly 16. For example, the capsule assembly 102 of the exhaust rocker arm assembly 16 (refer toFigure 2 ) The E-foot or capsule of ) can abut against the top surface 308. In operation, the capsule can be actuated (e.g., based on the exhaust cam profile) to push down the top surface 308 along the center of the valve bridge 100, thereby actuating the valve bridge 100. In this mode, the valve bridge 100 translates downward while maintaining its horizontal orientation, thus pushing the two valves downward to the same lift. In the illustrated exemplary embodiment, the top surface 308 can generally include a flat horizontal plane. Although described in a particular manner, the top surface 308 is not limited to this configuration. In this regard, the top surface 308 can have any suitable size and shape adapted to be operatively coupled to the exhaust rocker arm assembly 16.

[0033] As shown, the body 300 can include a recess 310, which can be disposed at the top surface 316 of the first end 302. In a specific embodiment, the recess 310 can be configured to be coupled or engaged with the engine-driven rocker arm assembly 18. For example, in some embodiments, the capsule assembly 102 of the engine-driven rocker arm assembly 18 (reference Figure 2 ) can include an E-foot or plunger shaped as a ball and configured to be at least partially received by the recess 310. In operation, the E-foot can be actuated (e.g., based on the engine braking cam profile) to push down the recess 310, thereby tilting the valve bridge 100. In the illustrated exemplary embodiment, the recess 310 can have a shape that is at least partially spire-shaped. For example, the spire can be curved to reflect or accommodate the spherical shape of the E-foot. After being constructed in this way, the contact between the valve bridge 100 and the E-foot can generally occur along a circular contact line 330. This advantageously reduces any point contact or edge-to-edge contact, thereby reducing contact stress and friction and improving the dynamics of the entire system. In addition, since the recess 310 is made to generally conform to the E-foot profile, the E-foot can be used as a guide to ensure the accurate positioning and movement of the valve bridge 100. For example, during engine braking, when the E-foot presses down the valve bridge 100 via the recess 310, the valve bridge 100 can be actuated to move relative to the valve in all three x, y, and z directions, i.e., the downward component of the E-foot movement causes the valve bridge 100 to tilt (e.g., as Figure 6Bmovements in the x and y directions caused by the same (as shown in

[0034] Figures 4A to 4B Figure 4), and a smaller movement in the z direction caused by the angular rotation of the E-foot (e.g., when the E-foot rotates downward, the valve bridge 100 can move slightly outward away from the axis of rotation). In this case, the recess 310 can include two parts, namely, a bottom part (e.g., the part below the circular contact line 330), a tip surface designed to contact the spherical surface of the E-foot; and an upper part (e.g., the part above the circular contact line 330) shaped as a frustum of a cone for guiding the E-foot at least in the x and y directions. For example, the configuration of the recess 310 can guide the valve bridge 100 to move in all three directions to ensure accurate alignment, e.g., this occurs when the valve bridge 100 rotates downward and when it moves upward back to its original horizontal position. It should be understood that although the present disclosure describes a valve bridge with a specific first end in a specific manner, the present disclosure also contemplates valve bridges with any suitable first end in any suitable manner. In this regard, for example, in some embodiments, the first end of the valve bridge can include other suitable structures adapted to kinematically coordinate with the rocker arm. For example, in some embodiments, the first end can be configured with a convex structure to match the concave E-foot, examples of which will be further described below.

[0034] Figures 4A to 4B Figure 4 shows a bottom perspective view of the valve bridge 100, and for better observation, some parts of the valve bridge 100 are cut away in Figure 4B Figure 4. In a specific embodiment, the main body 300 can further include a first valve seat 312 and a second valve seat 314. In a specific embodiment, the first valve seat 312 can be disposed at the bottom surface 318 of the first end 302 and is generally positioned along the x direction opposite to the recess 310. The first valve seat 312 can be a passage for receiving the first exhaust valve 26. For example, the top end 104A of the first exhaust valve 26 (refer to Figure 2) may be located in the first valve seat 312 and abut against a contact surface 320 at the bottom of the first valve seat 312. In a specific embodiment, the contact surface 320 may be shaped to have an S-shaped curvature. By way of example and not limitation, the contact surface 320 may include a substantially flat portion 328 that transitions between a first curved portion 322 and a second curved portion 324. As shown, the first curved portion 322 may be in a direction opposite to the second curved portion 324. For example, the unit normal vector of the first curved portion 322 may generally point upward, while the unit normal vector of the second curved portion 324 may generally point downward. As another example, the curvature of the first curved portion 322 may be the same as or different from the curvature of the second curved portion 324. In this way, by curving the contact surface 320, a constant line contact or surface contact with the associated valve can be maintained when the valve bridge 100 is tilted or translated. In an alternative embodiment, the contact surface 320 may have a first curved surface with a first radius and a second curved surface with a second radius. Additionally, a flat surface may be disposed between the first curved surface and the second curved surface. For example, the center of curvature of the first curved surface may be located above the first curved surface, while the center of curvature of the second curved surface may be located below the second curved surface. As another example, the first radius may be the same as or different from the second radius. In a specific embodiment, point contact or edge-to-edge contact may be eliminated or at least reduced to improve the kinematic performance of the system. This also facilitates the machining of the valve bridge and has better ergonomics structurally.

[0035] In a specific embodiment, the second valve seat 314 may be disposed at the bottom surface 326 of the second end 306 and is generally positioned opposite the first valve seat 312 along the y-direction. The second valve seat 314 may be a recess for receiving the second exhaust valve 28. For example, the top end 104B of the second exhaust valve 28 (reference Figure 2) can be assembled in the second valve seat 314 and abut against a contact surface at the bottom of the second valve seat 314. The contact surface can be flat or curved. As shown, the shape of the second valve seat 314 in the x-y plane can be generally circular. In a specific embodiment, the circular shape of the second valve seat 314 can be adapted to accommodate the shape of the tip 104B of the second exhaust valve 28. As a non-limiting example, the inner diameter of the second valve seat 314 can be slightly larger than the outer diameter of the tip 104B of the second exhaust valve 28, such that a radial clearance is formed between the second valve seat 314 and the second exhaust valve 28. This configuration can allow the valve bridge 100 to move (e.g., tilt) relative to the second exhaust valve 28 while ensuring accurate movement and / or force transmission when needed. Although described in this particular manner, it should be understood that the second valve seat 314 is not limited to this configuration. The second valve seat 314 can have any suitable size and shape known to those skilled in the art that is adapted to receive the tip 104B of the second exhaust valve 28.

[0036] Reference will now be made to Figures 5A to 6B describe the operation of the valve bridge 100 according to the present disclosure, wherein Figures 5A to 5B a side view of both the exhaust rocker arm assembly 16 and the engine braking rocker arm assembly 18 in a first position (e.g., in the drive mode) is shown, and Figures 6A to 6B a side view of both the exhaust rocker arm assembly 16 and the engine braking rocker arm assembly 18 in a second position (e.g., in the engine braking mode) is shown.

[0037] Referring to Figures 5A to 5B , for example, in the drive mode, the exhaust rocker arm assembly 16 can swing (e.g., in response to the main lift profile of the cam) and act on the valve bridge 100 by pressing against the top surface 308 of the valve bridge 100, thereby pushing the valve bridge 100 vertically downward. When this occurs, both the first exhaust valve and the second exhaust valve 26, 28 can be simultaneously driven to open. In other words, in the drive mode, when the valve bridge 100 is driven downward and the first exhaust valve and the second exhaust valve 26, 28 are opened to the same valve position, the horizontal axis or longitudinal axis of the valve bridge 100 can remain substantially perpendicular to the vertical axes of the first exhaust valve and the second exhaust valve 26, 28.

[0038] In addition, when in the driving mode, the engine actuating rocker arm assembly 18 can be located on the base circle or in a deactivated state. Alternatively or additionally, the first capsule 500 associated with the engine actuating rocker arm assembly 18 can be deactivated to prevent any actuating force or motion from being transmitted downward to the valve bridge 100. Even if the engine actuating rocker arm assembly 18 rotates, the valve bridge 100 (specifically, the recess 310) will not receive any actuating motion from the engine actuating rocker arm assembly 18. Although the first capsule 500 is depicted as being located within the recess 310 during the driving mode, other configurations of the first capsule 500 are also conceivable. For example, the first capsule 500 can be retracted upward (e.g., by a switchable system controlling the first capsule 500) to avoid contacting the valve bridge 100.

[0039] For example, referring to Figures 6A to 6B , in the engine braking mode, the exhaust rocker arm assembly 16 can be located on the base circle or in a deactivated state. Alternatively or additionally, the second capsule 502 associated with the exhaust rocker arm assembly 16 can be deactivated to prevent any actuating force or motion from being transmitted downward to the valve bridge 100. Even if the exhaust rocker arm assembly 16 rotates, the valve bridge 100 (specifically, the top surface 308) will not receive any actuating motion from the exhaust rocker arm assembly 16. For example, as depicted, the second capsule 502 can be spaced apart from and not in contact with the top surface 308. Alternatively, the second capsule 502 can be made telescopic, for example, by means of a lost motion mechanism or other suitable features well known to those skilled in the art.

[0040] In addition, when in the engine braking mode, the engine actuating rocker arm assembly 18 can rotate according to the lift profile of the engine braking cam. Further, the first capsule 500 is controlled to extend such that the E foot can push against the first end 302 to transmit motion to the first exhaust valve 26 without transmitting it to the second exhaust valve 28. That is, regardless of how the engine actuating rocker arm assembly 18 moves, the second exhaust valve 28 always remains in an unactuated state. During an engine braking event, the valve bridge 100 can tilt or pivot at an angle, where the first end 302 moves downward (e.g., generally around the tip 104B of the second exhaust valve 28). In other words, the first end 302 can travel downward and push the first exhaust valve 26 open, while the second end 306 generally remains in the same position without actuating the second exhaust valve 28.

[0041] In a specific embodiment, when the valve bridge 100 is tilted, slight drift may occur, which may cause the tip 104A of the first exhaust valve 26 to move within the first valve seat 312. For example, the tip 104A may initially be disposed against the flat portion 328 of the first valve seat 312. The drift may cause the tip 104A to move, thereby moving to the left of the flat portion 328 toward the first curved portion 322. In these embodiments, although the first exhaust valve 26 has a positional drift relative to the first valve seat 312, due to the shape of the first valve seat 312, the required force transmission can still be maintained, that is, the force applied to the first exhaust valve 26 can still be substantially the same as the force applied by the first capsule 500.

[0042] In a specific embodiment, the second valve seat 314 can also be configured to accommodate drift. By way of example and not limitation, as discussed above, the inner diameter of the second valve seat 314 can be greater than the outer diameter of the tip 104B of the second exhaust valve 28, such that the second exhaust valve 28 can move inside the second valve seat 314 (e.g., move to the left as shown). In addition, the depth of the second valve seat 314 can be designed to be deep enough so that when the valve bridge 100 is tilted, at least a portion of the tip 104B of the second exhaust valve 28 is always received within the second valve seat 314. This prevents the second exhaust valve 28 from detaching from the valve bridge 100.

[0043] In a specific embodiment, the engine braking lift can be about 4 mm. When the first capsule 500 is actuated to apply a downward force, the valve bridge 100 can tilt downward to overcome the biasing force applied by a valve spring (not shown) coupled to the first exhaust valve 26, thereby lifting the first exhaust valve 26 from a valve seat (not shown) by about 4 mm. At the same time, due to the tilt of the valve bridge 100, the force transmitted to the second exhaust valve 28 can be kept minimal or at least small enough compared to the biasing spring force such that the second exhaust valve 28 does not undergo vertical translation. By way of example and not limitation, the first exhaust valve 26 can withstand a force of 10 kN, and the second exhaust valve 28 can withstand a force of 0.5 kN. It should be understood that the embodiments provided herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure. For example, in some embodiments, the engine braking lift can be about 2 mm. In other embodiments, the engine braking lift can be less than 4 mm, greater than 4 mm, or other suitable values. In still other embodiments, the force borne by the first exhaust valve or the second exhaust valve can be less than or greater than the above values.

[0044] Figures 7 to 8 A second embodiment of a valve bridge according to the present disclosure is shown, wherein, Figure 7 a perspective view of the valve bridge 700 is shown, and Figure 8Is a side cross-sectional view of the valve bridge 700 during operation. In a particular embodiment, the valve bridge 700 may operate in a manner similar to the valve bridge 100, i.e., the valve bridge 700 may tilt when actuated by the engine rocker arm assembly 18 to press open the first exhaust valve 26 and the second exhaust valve 28, respectively. Additionally, the valve bridge 700 may be configured with a structure similar to the valve bridge 100, including a body 706 having a first end 708, a second end 710, a top surface 712, a recess 714, a first valve seat 716, and a second valve seat 718. In the illustrated embodiment, the valve bridge 700 may further include a kinematic cylinder 702 that may be rotatably disposed along the z-direction through a hole 720 at the second end 710. Additionally, the second valve seat 718 may lead to the hole 720, enabling access to the kinematic cylinder 702 inserted through the hole 720. By way of example and not limitation, the shape of the kinematic cylinder 702 may be generally cylindrical and have a flat surface 704 at the bottom. The flat surface 704 may be exposed through the second valve seat 718 such that the tip 104B of the second exhaust valve 28 may pass through the second valve seat 718 and contact the flat surface 704. In a particular embodiment, the kinematic cylinder 702 may be used to improve the kinematic performance of the overall system and increase the contact between the second exhaust valve 28 and the valve bridge 700. For example, when the valve bridge 700 rotates during engine braking mode, the kinematic cylinder 702 may rotate relative to the body 706 such that the flat surface 704 may maintain a larger contact area with the tip 104B of the second exhaust valve 28 and help prevent point contact that may occur due to the tilt of the valve bridge 700. This may be particularly useful for systems having floating components associated with the exhaust rocker arm assembly 16 that may affect the primary exhaust contact area between the second capsule 502 and the top surface 712 of the valve bridge 700, e.g., in the case of two-stroke engine braking.

[0045] Figures 9 to 10 Shows a third embodiment of a valve bridge according to the present disclosure, wherein, Figure 9 Shows a cross-sectional view of the valve bridge 900 for the rocker arm assembly 902 during engine braking, and Figure 10is a cross-sectional perspective view of valve bridge 900. In a specific embodiment, the operation of valve bridge 900 can be similar to that of valve bridge 700. That is, valve bridge 900 can tilt when actuated by the engine rocker arm assembly 904, thereby pressing to open the first exhaust valve 26 and the second exhaust valve 28 respectively. In addition, valve bridge 900 can be configured with a structure similar to that of valve bridge 700, including a body 906 having a first end 908, a second end 910, a top surface 912, a first valve seat 914, a second valve seat 916, and a kinematic column 918. In the illustrated embodiment, valve bridge 900 can further include a knob 920, which can be attached to the top of the first end 908. As shown, the knob 920 can include a protrusion at the top end of the knob 920, and the protrusion can be spherical, spire-shaped, or other smooth shapes. For example, the bottom of the knob 920 can be received by a recess 922 on the top surface of the first end 908 and extend upward to a specific height above the top surface of the first end 908. To engage with the knob 920, the capsule assembly 924 of the engine rocker arm assembly 904 can be configured with a recess or a recessed surface 926, which is shaped to fit the protrusion at the top end of the knob 920. Further illustration, for example, compared with the embodiment described above with reference to FIGS. 1 to Figure 8 The configuration of valve bridge 900 and the configuration of the engine rocker arm assembly 904 are opposite in the positions of the recess and the corresponding mating structure (e.g., E-foot or knob 920). In a specific embodiment, in addition to the above benefits of optimizing the kinematic performance of the system, the height of the knob 920 can advantageously be adjusted according to the packaging requirements. This can be particularly useful when different spaces need to be provided for the capsule assembly 924. By way of example and not limitation, the knob 920 can be removably received by the recess 922. Therefore, when a different height is needed, the knob 920 can be easily removed and replaced without having to replace the entire valve bridge 900.

[0046] Figures 11 to 12 A fourth embodiment of a valve bridge according to the present disclosure is shown, wherein, Figure 11 A cross-sectional view of valve bridge 1100 for a rocker arm assembly 1102 during engine braking is shown, and Figure 12It is a perspective view of the valve bridge 1100. In a specific embodiment, the valve bridge 1100 can operate in a manner similar to the valve bridge 100, that is, the valve bridge 1100 can tilt when actuated by the engine rocker arm assembly 1104, thereby pressing and opening the first exhaust valve 26 and the second exhaust valve 28 respectively. In addition, the valve bridge 1100 can be configured with a structure similar to that of the valve bridge 100, including a body 1106 having a first end 1108, a second end 1110, a top surface 1112, a recess 1114, a first valve seat 1116, and a second valve seat 1118. In the illustrated embodiment, the top surface 1112 can also be provided with surface structures for guiding the positioning or movement of the valve bridge 1100 when actuated by the exhaust rocker arm assembly 1120. By way of example and not limitation, a guiding structure 1122 can be provided on the top surface 1112, and the guiding structure can be formed as a groove, a channel, a protrusion, or other suitable features for engaging with the exhaust rocker arm assembly 1120. In the illustrated embodiment, the guiding structure 1122 includes a pair of walls 1124A and 1124B, which extend through the entire width of the valve bridge 1100, and a channel 1126 is defined between the pair of walls to receive the E-foot 1128 of the exhaust rocker arm assembly 1120. During operation, the valve bridge may experience undesirable drift, resulting in misalignment of the valve bridge relative to the exhaust rocker arm assembly. In such a case, the guiding structure 1122 can prevent the valve bridge 1100 from moving in the lateral direction and maintain the accurate orientation and positioning of the valve bridge relative to the exhaust rocker arm assembly 1120.

[0047] Various embodiments of the present disclosure can advantageously provide an optimized solution for the connection between the rocker arm and the valve to achieve improved motion and force transmission. By adopting the novel design according to the present disclosure, the valve bridge can achieve better kinematic performance while simplifying the structure and reducing the packaging space. One or more other advantages can be easily seen by those skilled in the art in combination with the drawings, the description, and the claims of the present disclosure.

[0048] In this document, unless otherwise clearly stated or the context otherwise indicates, "or" is inclusive rather than exclusive. Thus, in this document, unless otherwise clearly stated or the context otherwise indicates, "A or B" means "A, B, or both". In addition, unless otherwise clearly stated or the context otherwise indicates, "and" includes both connected and separated. Thus, in this document, unless otherwise clearly stated or the context otherwise indicates, "A and B" means "connected A and B or separated A and B".

[0049] The scope of the present disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments described or shown herein that would be understood by a person of ordinary skill in the art. The scope of the present disclosure is not limited to the exemplary embodiments described or shown herein. Additionally, although the various embodiments of the present disclosure are described and shown as including specific components, elements, features, functions, operations, or steps, any one of these embodiments can include any combination or arrangement of any components, elements, features, functions, operations, or steps described or shown anywhere herein that would be understood by a person of ordinary skill in the art. Further, a device, system, or component of a device or system that is recited in the appended claims as being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses such a device, system, or component, i.e., regardless of whether the device, system, or component is enabled, turned on, or unlocked to perform the particular function, so long as the device, system, or component is so adapted, arranged to, capable of, configured to, enabled to, operable to, or operative to perform the particular function. Additionally, although the present disclosure describes or shows particular embodiments that provide specific advantages, a particular embodiment may not provide those advantages, may provide some of the advantages, or may provide all of the advantages.

Claims

1. A valve bridge for a rocker arm assembly, the valve bridge comprising: a first end, a second end opposite the first end, and a top surface of a bridge body portion connecting the first end and the second end, wherein the top surface of the bridge body portion is configured to engage a first rocker arm; a first recess disposed at the top of the first end, wherein the first recess has at least a partially pointed top shape and is configured to engage a second rocker arm; a first valve seat disposed at the bottom of the first end and having a curved bottom surface for engaging a first valve; and a second valve seat disposed at the bottom of the second end for engaging a second valve; wherein the valve bridge is configured to: vertically translate when actuated by the first rocker arm, thereby actuating both the first valve and the second valve, or tilt at an angle when actuated by the second rocker arm, thereby actuating the first valve without actuating the second valve.

2. The valve bridge according to claim 1, wherein, the engagement between the first recess and the second rocker arm forms a circular contact line.

3. The valve bridge according to claim 1, wherein, the first valve seat is a channel.

4. The valve bridge according to claim 1, wherein, the curved bottom surface of the first valve seat is S-shaped.

5. The valve bridge according to claim 1, wherein, the curved bottom surface of the first valve seat allows the first valve to move laterally relative to the valve bridge.

6. The valve bridge according to claim 1, wherein, the second valve seat includes a second recess.

7. The valve bridge according to claim 1, wherein, the inner diameter of the second valve seat is greater than the outer diameter of the end of the second valve.

8. The valve bridge according to claim 1, wherein, the second end includes a horizontal through hole and a kinematic column rotatably inserted into the horizontal through hole.

9. The valve bridge according to claim 8, wherein, the kinematic column engages the second valve, and when the valve bridge tilts, the kinematic column maintains surface contact with the second valve.

10. The valve bridge according to claim 1, wherein, the top surface includes a guiding structure for guiding the movement of the valve bridge relative to the first rocker arm.

11. A valve bridge for a rocker arm assembly, the valve bridge comprising: a first end, a second end opposite the first end, and a top surface of a bridge body portion connecting the first end and the second end, wherein the top surface of the bridge body portion is configured to engage a first rocker arm; a protrusion disposed at the top of the first end, and the top of the protrusion has a pointed top shape for engaging a second rocker arm; a first valve seat disposed at the bottom of the first end and having a curved bottom surface for engaging a first valve; and a second valve seat disposed at the bottom of the second end for engaging a second valve; wherein the valve bridge is configured to: vertically translate when actuated by the first rocker arm, thereby actuating both the first valve and the second valve, or When actuated by the second rocker arm, it tilts at a certain angle, thereby actuating the first valve without actuating the second valve.

12. The valve bridge according to claim 11, wherein, The engagement between the protrusion and the second rocker arm forms a circular contact line.

13. The valve bridge according to claim 11, wherein, The protrusion is removably received by a recess disposed at the top of the first end.

14. The valve bridge according to claim 11, wherein, The curved bottom surface of the first valve seat is S-shaped.

15. The valve bridge according to claim 11, wherein, The curved bottom surface of the first valve seat allows the first valve to move laterally relative to the valve bridge.

16. A rocker arm assembly, comprising: A first rocker arm and a second rocker arm; A first valve and a second valve; and A valve bridge configured to be selectively actuated by the first rocker arm or the second rocker arm, the valve bridge comprising: A first end, a second end opposite the first end, and a top surface of a bridge body portion connecting the first end and the second end, wherein the top surface of the bridge body portion is configured to engage with the first rocker arm, A recess disposed at the top of the first end, wherein the recess has a shape that is at least partially pointed and is configured to engage with a spherical end of the second rocker arm, A first valve seat disposed at the bottom of the first end and having a curved bottom surface for engaging the first valve, and A second valve seat disposed at the bottom of the second end for engaging the second valve; wherein the valve bridge is configured to: Translate vertically when actuated by the first rocker arm, thereby actuating both the first valve and the second valve, or Tilt at a certain angle when actuated by the second rocker arm, thereby actuating the first valve without actuating the second valve.

17. The rocker arm assembly according to claim 16, wherein, The first rocker arm is an exhaust rocker arm and the second rocker arm is an engine timing rocker arm.

18. The rocker arm assembly according to claim 16, wherein, The engagement between the recess and the spherical end of the second rocker arm forms a circular contact line.

19. The rocker arm assembly according to claim 16, wherein, The second end includes a horizontal through-hole and a kinematic column rotatably inserted into the horizontal through-hole.

20. The rocker arm assembly according to claim 16, wherein, The top surface includes a guiding structure for guiding the movement of the valve bridge relative to the first rocker arm.

Images