초록 ▼

Exhaust valve mechanism with a rocker arm (1) having a hydraulic circuit with a hydraulically operated valve play absorbing piston element (7). The hydraulic circuit contains a piston pump (20, 21) housed in the rocker arm and which is driven by an ordinary cam lobe (4) on the engine cam shaft (5).

Exhaust valve mechanism with a rocker arm (1) having a hydraulic circuit with a hydraulically operated valve play absorbing piston element (7). The hydraulic circuit contains a piston pump (20, 21) housed in the rocker arm and which is driven by an ordinary cam lobe (4) on the engine cam shaft (5). The piston (21) of the piston pump has a cam follower (23) spaced at a predetermined cam angle distance (a) from the ordinary cam follower (3) of the rocker arm. The pump is in communication via a channel (24) and intermediate regulator valve (30) with the cylinder (6) of the valve play absorbing piston element. With the regulator valve, the piston element (7) can be shifted to open the exhaust valve during a latter portion compression stroke to achieve so-called compression braking.

대표청구항 ▼

In an exhaust valve mechanism in an internal combustion engine, comprising at least one exhaust valve in each cylinder, a rocker arm, mounted on a rocker arm shaft, for each cylinder for operating the exhaust valve, a cam shaft with a cam lobe for each rocker arm, said cam lobe being in contact with

In an exhaust valve mechanism in an internal combustion engine, comprising at least one exhaust valve in each cylinder, a rocker arm, mounted on a rocker arm shaft, for each cylinder for operating the exhaust valve, a cam shaft with a cam lobe for each rocker arm, said cam lobe being in contact with a first follower at one end of the rocker arm, a valve play absorbing device arranged between an opposite end of the rocker arm and the exhaust valve, said valve play absorbing device comprising a piston element, which is housed in a first cylinder chamber disposed in said opposite rocker arm end, and a hydraulic circuit for supplying and draining hydraulic oil to and from said first cylinder chamber, the improvement wherein the hydraulic circuit comprises a hydraulic pump housed in the rocker arm and driven by the cam lobe, said hydraulic pump having a second cam follower arranged at a predetermined cam angle distance (a) from the first cam follower and communicating via a channel with the first cylinder chamber.