Rocker system with stop device on cam side

Abstract

A rocker arm assembly for actuating a valve. The rocker arm assembly includes a rocker arm having a valve side and a cam side. The rocker arm is pivotable about a rocker axis via actuation on the cam side. At least one roller assembly is attached to the rocker arm. A latch assembly is provided for selectively locking the at least one roller assembly to the rocker arm, where the at least one roller assembly is free to pivot relative to the rocker arm when the latch assembly is in an idle state and the at least one roller assembly is pivotally coupled to the rocker arm when the latch assembly is in an active state.

Description

[0001] priority

[0002] This application claims the benefit of priority to Indian Provisional Patent Application Serial No. 202211037369 filed on June 29, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application generally relates to an integrated device for a rocker arm assembly. More specifically, the present application relates to a mechanism for preventing a hydraulic lash adjuster (HLA) of a rocker arm assembly from completely leaking. Background Art

[0004] Many internal combustion engines utilize hydraulic lash adjusters (HLAs) for use with rocker arm assemblies. During use, the HLAs often experience complete fluid leakage or exhaustion. It would be desirable to have a mechanism that would prevent complete fluid leakage from the HLA during operation of the rocker arm assembly. Summary of the invention

[0005] A rocker arm assembly for actuating a valve is provided. The rocker arm assembly includes a rocker arm having a valve side and a cam side. The rocker arm can pivot about a rocker shaft via actuation of the cam side. A hydraulic lift assembly is located on the valve side of the rocker arm. The hydraulic lift assembly includes a plunger that can move between an actuated position and an unactuated position. A check ball is provided for selectively locking the plunger in the actuated position. At least one roller assembly is attached to the rocker arm. A latch assembly is provided for selectively locking the at least one roller assembly to the rocker arm, wherein when the latch assembly is in an idle state, the at least one roller assembly is free to pivot relative to the rocker arm, and when the latch assembly is in an activated state, the at least one roller assembly can be pivotally connected to the rocker arm.

[0006] In the above embodiment, at least one roller assembly includes a roller that can engage with the cam. The roller is configured to pivot about the rocker shaft. A spring is provided for biasing the roller to a stop position. A stopper is provided for stopping the roller at the stop position.

[0007] In the above described embodiments, the stopper is a single pin.

[0008] In the above embodiment, the stopper is connected to the rocker arm by at least one of threading, welding or press fitting.

[0009] In the above embodiment, the stopper engages with a seat formed in the rocker arm.

[0010] In the above embodiment, the rocker arm has a Y-shape having a first arm and a second arm.

[0011] In the above embodiment, one end of the spring is fixed to the rocker arm, and the other end of the spring is engaged with the bracket holding the second roller.

[0012] In the above-described embodiment, the bracket is pivotable about the rocker axis.

[0013] A rocker arm assembly for actuating a valve is also provided. The rocker arm assembly includes a rocker arm having a valve side and a cam side. The rocker arm is pivotable about a rocker axis via actuation of a first roller on the cam side. At least one roller assembly is attached to the rocker arm. A latch assembly is provided for selectively locking the at least one roller assembly to the rocker arm, wherein when the latch assembly is in an idle state, the at least one roller assembly is free to pivot relative to the rocker arm, and when the latch assembly is in an activated state, the at least one roller assembly is pivotably coupled to the rocker arm.

[0014] In the above embodiment, at least one roller assembly includes a roller that can engage with the cam. The roller is configured to pivot about the rocker shaft. A spring is provided for biasing the roller to a stop position. A stopper is provided for stopping the roller at the stop position.

[0015] In the above described embodiments, the stopper is a single pin.

[0016] In the above embodiments, the stopper is connected to the rocker arm by at least one of threading, welding or press fitting.

[0017] In the above embodiment, the stopper engages with a seat formed in the rocker arm.

[0018] In the above embodiment, one end of the spring is fixed to the rocker arm, and the other end of the spring is engaged with the bracket holding the second roller.

[0019] In the above-described embodiment, the bracket is pivotable about the rocker axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a perspective view of the rocker arm assembly;

[0021] Figure 2 It is taken along line 2-2 Figure 1 A cross-sectional view of a rocker arm assembly in FIG. 1 showing a hydraulic lift assembly (HLA) in a deactivated state;

[0022] Figure 3 yes Figure 2 An enlarged cross-sectional view of HLA in;

[0023] Figure 4 It is taken along line 4-4 Figure 1A cross-sectional view of a latch assembly of a rocker arm assembly in FIG. 1 , showing the latch assembly in an idle state;

[0024] Figure 5 is a graph of valve lift versus cam angle for a latch assembly in an idle state;

[0025] Figure 6 It is taken along line 4-4 Figure 1 a cross-sectional view of a latch assembly of a rocker arm assembly in FIG. 1 , showing the latch assembly in an activated state; and

[0026] Figure 7 is a graph of valve lift versus cam angle with the latch assembly in the enabled state. DETAILED DESCRIPTION

[0027] A description of the present disclosure is given below; however, various aspects may be embodied in a variety of different forms and should not be construed as limited to the embodiments set forth herein. In addition, the following examples may be provided individually or in combination with one or any combination of the examples discussed herein. Directional references such as "left" and "right" are for ease of reference to the accompanying drawings.

[0028] refer to Figure 1 , the rocker arm assembly 50 includes a rocker arm 60. In the illustrated embodiment, the rocker arm 60 is a Y-shaped rocker arm having a first arm 60a and a second arm 60b. It is contemplated that the rocker arm 60 may be a single rocker arm (not shown). A hydraulic lash adjuster (HLA) 100 is located on the valve side 62 of the rocker arm 60. The HLA 100 is positioned to selectively engage the distal end (at the distal end) of the valve 80 when the lash of the valve 80 needs to be adjusted. Figure 2 and Figure 3 In the illustrated embodiment, the rocker arm 60 includes a rocker hole 66 to allow the rocker arm 60 to be moved via a cam 70 (in Figure 2 The cam 70 is partially shown in the figure and pivots around an axis (not shown) by actuation at the roller end 64 of the rocker arm 60. A first roller 65 for engaging with the cam 70 is arranged at the roller end 64.

[0029] refer to Figure 2 and Figure 3, the rocker arm 60 includes a bore 68 sized to receive the HLA 100. Generally, the HLA 100 includes an upper piston 102 and a lower piston 104, which together define a first fluid chamber 110 therebetween. The lower piston 104 and the plunger 112 of the HLA 100 define a second fluid chamber 120 therebetween. When it is desired to extend the plunger 112 from the bore 68, fluid is supplied to the first fluid chamber 110. The check ball 122 in the HLA 100 opens due to the force generated by the fluid flowing into the first fluid chamber 110, thereby allowing the fluid to flow into and fill the second fluid chamber 120. When the first fluid chamber 110 and the second fluid chamber 120 are filled, the plunger 112 extends a predetermined distance from the bore 68 of the rocker arm 60 to reach an extended position.

[0030] When the plunger 112 is subjected to a sudden force, such as a force generated by a spring (not shown) on the valve 80, the force suddenly applied to the distal end of the plunger 112 causes the plunger 112 to move slightly toward the lower piston 104. This movement causes a sudden increase in pressure in the second fluid chamber 120, which causes the check ball 122 to seat against the lower piston 104 in a sealing manner and close the opening 105 extending through the lower piston 104. With the opening 105 closed, the pressurized fluid is "locked" into the second fluid chamber 120, and the entire HLA 100 acts as a solid component so that the force from the rocker arm assembly 50 can be transmitted through the HLA 100 to the valve 80 to move the valve 80 to the desired position.

[0031] After the resistance from the valve 80 is eliminated, for example, when the rocker arm assembly 50 is pivoted to a position where no force is applied to the valve 80, the resistance generated by the spring (not shown) on the valve 80 is eliminated and the pressure in the second fluid chamber 120 is released. When the plunger 112 returns to the retracted position, the fluid in the second fluid chamber 120 leaks into the surrounding environment.

[0032] The rocker arm assembly 50 includes a latch assembly 150 for selectively locking or connecting the roller assembly 200 to the rocker arm 60. Figure 4 , the latch assembly 150 generally includes a plug 152 that is movable within the hole 67 of the rocker arm 60 and the hole 202 of the roller assembly 200. Figure 4 In the embodiment shown in FIG. 1 , the plug 152 moves in the sleeve 67a in the rocker arm 60 and the sleeve 202a in the roller assembly 200, respectively. When in the inactive position (eg, Figure 4), the roller assembly 200 is unlocked from the rocker arm 60, so that the pivoting of the rocker arm 60 about the rocker shaft (not shown) and the movement of the roller assembly 200 about the rocker shaft (not shown) are independent or separated from each other. In other words, the movement of the roller assembly 200 in the direction of arrow C is not associated with the movement of the rocker arm 60 in the direction of arrow B. Since the movement of the rocker arm 60 is not transmitted to the roller assembly 200, that is, the movement of the rocker arm 60 is "idle", this non-association is also called "idle motion".

[0033] refer to Figure 5 , when the latch assembly 150 is deactivated, that is, the roller assembly 200 is disassociated from the rocker arm 60. In this position, the valve lift of the valve 80 follows Figure 5 The solid line in .

[0034] refer to Figure 6 , when the latch assembly 150 is enabled, the plug 152 is partially located within the hole 67 of the rocker arm 60 and the hole 202 of the roller assembly 200. In this position, the roller assembly 200 is coupled to the rocker arm 60 so that they move as a unit about the rocker shaft (not shown). In other words, the movement of the roller assembly 200 in the direction of arrow D is coupled to the movement of the rocker arm 60 in the direction of arrow E. Figure 7 When the roller assembly 200 is locked to the rocker arm 60 , the displacement of the valve 80 is controlled by the rocker arm 60 until the transition point A. After the transition point A, the displacement of the valve 80 is controlled by the roller assembly 200 .

[0035] Return to reference Figure 1 and Figure 2 , the roller assembly 200 generally includes a second roller 204 disposed in a bracket 206 that pivots about a rocker shaft (not shown). A stop or pin 208 extends through the bracket 206 and is configured to engage a seat 69 formed in the rocker arm 60. A retaining pin 212 ( Figure 2 ) to retain the stopper 208 in the bracket 206.

[0036] A spring 214 is disposed in the bracket 206 for biasing the bracket 206 so that the stopper 208 engages the seat 69. In the illustrated embodiment, one end of the spring 214 engages a plate 216 attached to the rocker arm 60, and the other end of the spring 214 engages the bracket 206. Bolts 218 may be provided to secure the plate 216 to the mounting arm 71 of the rocker arm 60.

[0037] During operation, when the latch assembly 150 is in the activated position ( Figure 6), since the latch assembly 150 allows the roller assembly 200 and the rocker arm 60 to function as a unit, the force applied by the spring on the valve 80 is resisted by the cam 70 through the latch assembly 150. The stopper 208 and the seat 69 on the rocker arm 60 are positioned so that in this position, the plug 152 is aligned with the hole 67 of the rocker arm 60 and the hole 202 of the roller assembly 200, respectively. When the latch assembly 150 is moved to the deactivated position ( Figure 4 ), the spring 214 keeps applying pressure to the HLA 100. By keeping this force applied, the high pressure generated in the second fluid chamber 120 of the HLA 100 remains constant, so that the lock applied by the HLA 100 can be used for continuous cycles.

[0038] The stop pin 208 is positioned so that the roller assembly 200 stops at the same position when it moves as when the latch assembly 150 is activated. When the latch assembly 150 is activated, the rocker arm 60 and the roller assembly 200 (acting as a whole) apply pressure to the HLA 100. When the latch assembly 150 is deactivated, the spring 214 maintains pressure on the HLA 100. By maintaining pressure on the HLA 100, the high pressure generated in the second fluid chamber 120 of the HLA 100 remains constant, so that the lock applied by the HLA 100 can be used for continuous cycles.

[0039] The stopper 208 thus provides a means for preventing a complete leak of the HLA 100. By preventing a complete leak, the stopper 208 may allow the HLA 100 to be used in a continuous cycle.

[0040] It is contemplated that the stop 208 may be a separate component added to the rocker arm 60, such as by threading, press fitting, welding, etc., or the stop 208 may be a component formed integrally with the rocker arm, such as being attached to the body of the rocker arm during molding of the rocker arm or being machined into the body of the rocker arm. In the illustrated embodiment, the stop 208 is an elongated pin. It is contemplated that the stop 208 may have other shapes, such as a protrusion or projection extending from the bracket 206, as long as they are positioned and sized to engage with the seat 69 of the rocker arm 60.

[0041] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention as claimed.

Claims

1. A rocker arm assembly for actuating a valve, the rocker arm assembly comprising: a rocker arm having a valve side and a cam side, the rocker arm being pivotable about a rocker axis via actuation of the cam side; A hydraulic lifting assembly is located on the valve side of the rocker arm, and the hydraulic lifting assembly includes: a plunger movable between an actuated position and an unactuated position; and a check ball for selectively locking the plunger in the actuated position; at least one roller assembly attached to the rocker arm; and A latch assembly for selectively locking the at least one roller assembly to the rocker arm, wherein the at least one roller assembly is free to pivot relative to the rocker arm when the latch assembly is in an idle state, and the at least one roller assembly is pivotally coupled to the rocker arm when the latch assembly is in an engaged state.

2. The rocker arm assembly according to claim 1, wherein: The at least one roller assembly comprises: a roller engageable with the cam, the roller being configured to pivot about the rocker shaft; a spring for biasing the roller into a stopped position; and A stopper is used to stop the roller at the stop position.

3. The rocker arm assembly according to claim 2, wherein: The stop is a single pin.

4. The rocker arm assembly according to claim 2, wherein: The stop is connected to the rocker arm by at least one of threading, welding, or press fitting.

5. The rocker arm assembly according to claim 2, wherein: The stop engages a seat formed in the rocker arm.

6. The rocker arm assembly according to claim 1, wherein: The rocker arm has a Y-shape having a first arm and a second arm.

7. The rocker arm assembly according to claim 2, wherein: One end of the spring is fixed to the rocker arm, and the other end of the spring engages with a bracket that holds the roller.

8. The rocker arm assembly according to claim 7, wherein: The bracket is pivotable about the rocker axis.

9. A rocker arm assembly for actuating a valve, the rocker arm assembly comprising: a rocker arm having a valve side and a cam side, the rocker arm being pivotable about a rocker axis via actuation of a first roller on the cam side; at least one roller assembly attached to the rocker arm; as well as A latch assembly for selectively locking the at least one roller assembly to the rocker arm, wherein the at least one roller assembly is free to pivot relative to the rocker arm when the latch assembly is in an idle state, and the at least one roller assembly is pivotally coupled to the rocker arm when the latch assembly is in an engaged state.

10. The rocker arm assembly according to claim 9, wherein: The at least one roller assembly comprises: a roller engageable with the cam, the roller being configured to pivot about the rocker shaft; a spring for biasing the roller into a stopped position; and A stopper is used to stop the roller at the stop position.

11. The rocker arm assembly according to claim 10, wherein: The stop is a single pin.

12. The rocker arm assembly according to claim 10, wherein: The stop is connected to the rocker arm by at least one of threading, welding, or press fitting.

13. The rocker arm assembly according to claim 10, wherein: The stop engages a seat formed in the rocker arm.

14. The rocker arm assembly according to claim 10, wherein: One end of the spring is fixed to the rocker arm, and the other end of the spring engages with a bracket that holds the roller.

15. The rocker arm assembly according to claim 14, wherein: The bracket is pivotable about the rocker axis.

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