Engine brake system

摘要

An engine brake system comprising, in combination, a power absorbing oil pump driven in operative linkage with the crank shaft of the engine and a mechanism for controlling discharge pressure of said oil pump is disclosed. The pressure control mechanism comprises a main valve designed to be opened with a lift inversely proportional to the braking torque of the engine, a mechanism for adjusting the pressure on the back side of the main valve and a valve for switching the pressure on the back side of the main valve, all of which are provided in a valve box having an oil hole communicated with the discharge port of the oil pump. According to this system, in accordance as the engine speed increases, the lift of the main valve is reduced to elevate the power absorbed by the oil pump. Thus, this system is particularly useful for engine brake for vehicles.