Integrated rocker brake with reset plunger for actuating a single engine valve

Abstract

A rocker arm comprises a biasing contact surface configured to receive a force to bias the rocker toward a first engine valve. An actuator piston is slidably disposed in a vertical bore of the rocker arm, where the actuator piston and vertical bore are configured to align with the first engine valve. A hydraulic chamber is in fluid communication with the vertical bore, and a checking element is in fluid communication with the hydraulic chamber and configured to permit one-way passage of hydraulic fluid into the hydraulic chamber. A reset plunger is in sealing engagement with a reset plunger bore that is in fluid communication with the hydraulic chamber. The reset plunger has an end extending out of the rocker arm and configured to contact a reaction surface, thereby interrupting the sealing engagement of the reset plunger and permitting hydraulic fluid to vent out of the hydraulic chamber.

What is claimed is: 
     
         1 . A rocker arm for actuating at least a first engine valve in an internal combustion engine and having a motion imparting end, the rocker arm comprising:
 a biasing contact surface configured to receive a force to bias the motion imparting end toward the at least the first engine valve;   an actuator piston slidably disposed in a vertical bore formed in the motion imparting end of the rocker arm, the actuator piston and vertical bore configured to align with the at least the first engine valve;   a hydraulic chamber in fluid communication with the vertical bore;   a checking element in fluid communication with the hydraulic chamber and configured to permit one-way passage of selectively applied hydraulic fluid into the hydraulic chamber; and   a reset plunger in sealing engagement with a reset plunger bore that is in fluid communication with the hydraulic chamber, the reset plunger having an end extending out of the rocker arm and configured to contact a reaction surface external to the rocker arm in response to positioning of the rocker arm, thereby interrupting the sealing engagement of the reset plunger with the reset plunger bore and permitting hydraulic fluid to vent out of the hydraulic chamber.   
     
     
         2 . The rocker arm of  claim 1 , wherein the biasing contact surface is disposed on an upward facing surface of the rocker arm. 
     
     
         3 . The rocker arm of  claim 2 , the rocker arm comprising a lateral projection wherein the biasing contact surface is formed on the lateral projection. 
     
     
         4 . The rocker arm of  claim 1 , wherein the actuator piston includes a resilient element to bias the actuator piston into the vertical bore. 
     
     
         5 . The rocker arm of  claim 4 , further comprising:
 an actuator piston spring is disposed within the actuator piston and vertical bore and configured to bias the actuator piston into the vertical bore.   
     
     
         6 . The rocker arm of  claim 1 , the hydraulic chamber comprising a first bore parallel to an axis of rotation of the rocker arm, wherein the checking element is arranged in the first bore. 
     
     
         7 . The valve actuation system of  claim 1 , wherein the reset plunger is biased into sealing engagement with the reset plunger bore. 
     
     
         8 . The rocker arm of  claim 7 , further comprising a reset plunger spring configured to bias the reset plunger into sealing engagement with the reset plunger bore. 
     
     
         9 . The rocker arm of  claim 1 , wherein the reset plunger bore is perpendicular to an axis of rotation of the rocker arm. 
     
     
         10 . The rocker arm of  claim 9 , further comprising a reset plunger sleeve disposed within a second bore formed in the rocker arm, the reset plunger sleeve defining the reset plunger bore. 
     
     
         11 . A valve actuation system for actuating the first engine valve and comprising the rocker arm of  claim 1 , wherein the rocker arm is rotatably mounted on a rocker shaft, the system further comprising a resilient element attached to the rocker shaft and configured to apply the force to the biasing contact surface. 
     
     
         12 . A valve actuation system for actuating the first engine valve and comprising the rocker arm of  claim 1 , the system further comprising a fixed structure relative to movement of the rocker arm, wherein the reaction surface is formed on the fixed structure. 
     
     
         13 . The valve actuation system of  claim 12 , wherein the fixed structure is a camshaft bearing support. 
     
     
         14 . A valve actuation system for actuating at least two engine valves, wherein the at least two engine valves include the first engine valve, the valve actuation system comprising the rocker arm of  claim 1 . 
     
     
         15 . The valve actuation system of  claim 14 , further comprising another rocker arm for actuating a second engine valve of the at least two engine valves. 
     
     
         16 . The valve actuation system of  claim 15 , further comprising a first valve actuation motion source configured to provide a main event valve actuation motion and one or more first auxiliary valve actuation motions to the first engine valve. 
     
     
         17 . The valve actuation system of  claim 16 , further comprising a second valve actuation motion source configured to provide the main event valve actuation motion and one or more second auxiliary valve actuation motions to the second engine valve, wherein the first auxiliary valve actuation motions are not identical to the second auxiliary valve actuation motions. 
     
     
         18 . A valve actuation system for actuating at least two engine valves, wherein the at least two engine valves include the first engine valve, wherein the system includes a first rocker arm for actuating the first engine valve and a second rocker arm for actuating a second engine valve of the at least two engine valves, and wherein the first and second rocker arms are rocker arms in accordance with  claim 1 .