PURPOSE: To promote the improvement of a braking effect in an engine being accurately and easily controlled in its brake torque by providing a main valve opened in inverse proportion to the brake torque, back pressure adjusting mechanism of the main valve and a back pressure opening and closing valve in a valve casing communicating with a delivery port of a power absorbing pump driven by a crankshaft of the engine.
CONSTITUTION: An oil conducting hole 6, which communicates with a delivery port of a power absorbing gear pump 2 driven by a crankshaft of an engine through a drive piece 1, is provided in a valve casing 5. While providing a main valve 15, having a small hole communication hole 14, between the oil conducting hole 6 and an oil reservoir 7 and between the hole 6 and a valve unit guide hole 8, a control hole 17 is opened and closed by a selector valve 4. Further providing a conical valve unit 21 and a spring 22, which adjust a back pressure of the main valve 15, in a valve unit guide hole 8 and a brake pressure valve unit 31 and a coil spring 32 in a brake pressure conducting hole 28 opened to the oil conducting hole 6, the gear pump 2 is controlled in its maximum pressure. Accordingly, accurately and easily controlling brake torque, a braking effect can be improved.
HASEGAWA AKIRA
NOJIMA HIROSHI
MURATA MITSUHIRO
ISUZU MOTORS LTD
| JPS49111066A | 1974-10-23 |