Abstract: A work brake apparatus for a wheel type excavator having a travelling device, a suspension device, and a service brake device. The work brake apparatus comprises: a first means, which is connected to the forward/backward lever of the travelling device, for unlocking the suspension device as the suspension locking solenoid valve switches over in response to a predetermined signal when the forward/backward lever switches over to its forward or backward position, and a second means, which is connected to the forward/backward lever of the travelling device, for keeping the service brake applied as the service brake valve switches over in response to a predetermined pilot pressure when the forward/backward lever switches over to its neutral position.

Abstract: A device for matching the operation of a travelling unit in a construction vehicle is disclosed. The device reduces the required levering force of a travelling control pedal, easily controls the rotating force of an engine, and safely changes the engine output torque in accordance with both the levering stroke of the travelling control pedal and a travelling resistance. The device has a pressure reduction valve which is synchronized with a levering motion of a travelling control pedal in order to feed pilot fluid from a pilot pump to a direction select valve. A branch line is branched from a fluid line extending between the pressure reduction valve and the direction select valve. A hydraulic cylinder is connected to the branch line and selectively receives the pilot fluid through the branch line when the travelling control pedal is levered.