Combined engine braking and positive power engine lost motion valve actuation system

A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge eachreceive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge toactuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin. 种用于致动个或多个发动机阀以用于正功率操作和发动机制动操作的系统被公开。在优选的实施例中，排放阀桥部和吸入阀桥部各受到来自两组摇杆臂的阀致动。每个阀桥部包括用于致动单个发动机阀的滑动销和布置在阀桥部的中心中用以通过桥部来致动两个发动机阀的外柱塞。每个阀桥部的外柱塞可选择性地锁定于它的阀桥部，以提供正功率阀致动。在发动机制动过程中，应用于外柱塞的液压可使相