An air brake relay valve includes an air guide unit having a movable set, a drive unit having a motor and a worm shaft, and a cam unit having a transmission member and a driven member. During a brake action, the motor rotates the worm shaft to rotate the transmission member so as to push the driven member downward to thereby move the movable set to a communicating position where a first valve opening and a second valve opening fluidly communicate with each other. When the brake action is released, the motor rotates reversely so that the driven member is moved upward and that the movable set moves, without being applied with additional force, to a non-communicating position where the first and second valve openings do not fluidly communicate.

An air brake relay valve includes an air guide unit having a movable set, a drive unit having a motor and a worm shaft, and a cam unit having a transmission member and a driven member. During a brake action, the motor rotates the worm shaft to rotate the transmission member so as to push the driven member downward to thereby move the movable set to a communicating position where a first valve opening and a second valve opening fluidly communicate with each other. When the brake action is released, the motor rotates reversely so that the driven member is moved upward and that the movable set moves, without being applied with additional force, to a non-communicating position where the first and second valve openings do not fluidly communicate.

A brake apparatus is provided which has applicability to a wide range of vehicles. The brake apparatus includes a master cylinder provided in such a manner that a piston is axially operable in a master cylinder housing, and a stroke simulator including a reaction force piston axially operable by brake fluid introduced into a stroke simulator housing. The master cylinder housing is fixed to the stroke simulator housing. The stroke simulator housing is positioned between the master cylinder housing and a fixation piece structured to fix the stroke simulator housing to the vehicle. The fixation piece is spaced from the master cylinder housing.

A brake apparatus is provided which has applicability to a wide range of vehicles. The brake apparatus includes a master cylinder provided in such a manner that a piston is axially operable in a master cylinder housing, and a stroke simulator including a reaction force piston axially operable by brake fluid introduced into a stroke simulator housing. The master cylinder housing is fixed to the stroke simulator housing. The stroke simulator housing is positioned between the master cylinder housing and a fixation piece structured to fix the stroke simulator housing to the vehicle. The fixation piece is spaced from the master cylinder housing.

An electrohydraulic transmission control system having a parking lock valve by which a parking lock cylinder of a parking lock device can be charged with an actuation pressure adjustable in an operating-state-dependent manner by at least one pilot pressure adjustable in the region of an electrohydraulic pressure adjuster and/or one pressure source. Above a defined actuation pressure level, the parking lock valve is held in a defined operating state in which the actuation pressure can be applied to the parking lock cylinder. The actuation and pilot pressures can be applied to a valve device such that when the actuation and pilot pressure levels approximately correspond to one another, the region of the control system which conducts the actuation pressure is operatively connected, upstream of the parking lock valve, to a pressure region in the region of the valve device with a pressure lower than the defined actuation pressure level.

An electrohydraulic transmission control system having a parking lock valve by which a parking lock cylinder of a parking lock device can be charged with an actuation pressure adjustable in an operating-state-dependent manner by at least one pilot pressure adjustable in the region of an electrohydraulic pressure adjuster and/or one pressure source. Above a defined actuation pressure level, the parking lock valve is held in a defined operating state in which the actuation pressure can be applied to the parking lock cylinder. The actuation and pilot pressures can be applied to a valve device such that when the actuation and pilot pressure levels approximately correspond to one another, the region of the control system which conducts the actuation pressure is operatively connected, upstream of the parking lock valve, to a pressure region in the region of the valve device with a pressure lower than the defined actuation pressure level.

A work vehicle according to the present invention includes an engine installed in a traveling machine body supported by traveling units, and a transmission case incorporating a hydraulic continuously variable transmission. The transmission case incorporates a forward/backward traveling switching mechanism. The work vehicle includes forward traveling valves for forward traveling hydraulic clutches, a backward traveling valve for a backward traveling hydraulic clutch, and a master valve configured to control hydraulic oil supplying to the forward traveling valves and the backward traveling valve. A part of a hydraulic circuit is formed on a front lid member of the transmission case. The forward traveling valves, the backward traveling valve, and the master valve are attached on a front surface side of the front lid member.

A work vehicle according to the present invention includes an engine installed in a traveling machine body supported by traveling units, and a transmission case incorporating a hydraulic continuously variable transmission. The transmission case incorporates a forward/backward traveling switching mechanism. The work vehicle includes forward traveling valves for forward traveling hydraulic clutches, a backward traveling valve for a backward traveling hydraulic clutch, and a master valve configured to control hydraulic oil supplying to the forward traveling valves and the backward traveling valve. A part of a hydraulic circuit is formed on a front lid member of the transmission case. The forward traveling valves, the backward traveling valve, and the master valve are attached on a front surface side of the front lid member.

A towable crash-attenuating vehicle is shown having a frame; at least two axles coupled to the frame, each of the axles having wheels attached thereto; a ballast coupled to the frame; deflection shields coupled to the right and left sides of the frame, wherein the deflection shields cover the frame and a majority of the wheels on each side of the vehicle; a tow connection coupled to the front of the frame; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein the vehicle is provided with an mechanism for locking and unlocking the brake system.

A towable crash-attenuating vehicle is shown having a frame; at least two axles coupled to the frame, each of the axles having wheels attached thereto; a ballast coupled to the frame; deflection shields coupled to the right and left sides of the frame, wherein the deflection shields cover the frame and a majority of the wheels on each side of the vehicle; a tow connection coupled to the front of the frame; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein the vehicle is provided with an mechanism for locking and unlocking the brake system.