Exhaust valve brake for IC engine - uses hydraulic plunger in tappet to cyclically increase valve drive-line effective length

摘要

The IC engine internal braking system is based on opening the exhaust valves briefly as the associated pistons near compression/ignition TDC. Each exhaust valve operating linkage (9,11,12) embodies a telescopic element, controllably extendable to increase the linkages effective length and open the valve. This can be a plunger (10) housed in the tappet (9), hydraulically operated by oil cyclically acted upon a cam-driven piston. The cam drive, operating at half engine speed, is pref. an extension of the camshaft, viz. a single cam with the appropriate number of pistons radially around it.