A brake system includes a pneumatic circuit provided with a first and a second passage that supply compressed air from an air tank that stores compressed air to a brake booster; and a control unit that controls a proportional control valve arranged on the second passage. The control unit includes a first signal generator configured to generate a first signal that is a pulse signal having a first frequency and indicates a drive amount of the proportional control valve. The control unit also includes a second signal generator configured to generate a second signal that is a pulse signal having a second frequency, which is less than or equal to one-tenth of the first frequency. The control unit further includes a third signal generator configured to generate a command signal for the proportional control valve by multiplying the first signal by the second signal.

An air treatment unit for a brake system of a utility vehicle includes a foot brake module connection for pneumatically coupling the air treatment system to a foot brake module of the brake system, at least one valve unit for supplying the foot brake module connection with a control pressure, and a control device for controlling the valve unit.

A method for adjusting brake pressures on pneumatically operated wheel brakes of a motor vehicle includes adjusting, in a normal braking mode, the brake pressures depending on a driver brake request; and adjusting, by a control unit in a pressure control mode, the brake pressures at the respective wheel brakes during reception of an external brake request, which is independent of the driver brake request and defined for the control unit as an external target deceleration value, as a function of a resulting target deceleration value of the vehicle deceleration. The control unit determines the resulting target deceleration value by linking the external target deceleration value according to the external brake request and a value corresponding to the driver brake request. A braking power index is determined which quantitatively represents the braking effect of the wheel brakes, and is provided to be taken into account in pressure control mode.

When a brake system on a commercial vehicle, lateral acceleration and/or yaw of the vehicle are monitored and compared to a first predetermined threshold. If the first predetermined threshold is exceeded, a precharge command is sent to the brake system to precharge one or more air chambers by temporarily deactivating a modulator valve and activating an antilock traction relay valve in order to charge the air chambers up to a level permitted by the modulator valve. Upon detecting a panic braking event, a command signal is sent to the brake system to release the precharged air to facilitate braking.

A brake modulator (1) for a compressed air braking system (80) of a vehicle is disclosed. The brake modulator (1) has a main housing (8) and two relay valves (2, 3). Each relay valve is configured with a delivery valve seat (31, 131) and a vent valve seat (30, 130) and a vent position, wherein compressed air inlets (2d, 3d) are connected via a transverse bore (27) to a common compressed air inlet port (25, 26), and a delivery duct (12a, 112a) extends in the axial direction (A) in each relay valve (2, 3). The relay valves (2, 3) have guide body inserts (12, 112) which are inserted into a longitudinal bore (29) of the main housing (8), which longitudinal bore (29) extends in the axial direction (A), and the relay valves (2, 3) in each case have the delivery duct (12a, 112a).

A system and method for allowing failover between an autonomously controlled braking system and a human controlled braking system in a truck having pneumatic brake lines is provided. A cab-mounted brake actuator is arranged to be handled by the human operator and is arranged to selectively deliver pressurized air to truck brakes and a trailer brake air supply. A controller performs autonomous braking operations in response to control inputs and senses when a human operator is handling the actuator. A plurality of valves, interconnected between a pressurized air source on the truck, the actuator, the truck brakes and the trailer brake air supply, are responsive to the controller, and are arranged to override selective delivery of pressurized air to the truck brakes of the truck and the trailer brake air supply in response to the autonomous braking operations in favor of selective delivery of pressurized air via the actuator.

A service brake device for vehicles is provided which permits rapid venting of a service brake pressure chamber. The service brake device includes at least one pneumatic service brake device with at least one piston and/or a diaphragm. The piston and/or diaphragm delimits the service brake pressure chamber on one side which can be supplied with compressed air from a brake line for applying the service brake and can be purged of compressed air for releasing the service brake, delimits a spring chamber on the other side which receives a spring that prestresses the piston and/or the diaphragm in the release position of the service brake. The pressure chamber includes a pressure connection communicating with the brake line. A quick air release valve between the brake line and the pressure chamber is arranged to connect the brake line to the pressure chamber when the pressure in the brake chamber is greater than in the pressure chamber, and to connect the pressure chamber to the spring chamber when the pressure in the pressure chamber is greater than the brake line pressure.

A valve unit (1, 1) for modulating the pressure in a pneumatic brake system, has a brake pressure inlet (3), a brake pressure outlet (4) and a venting outlet (5), a pneumatically controllable main valve (6, 7) and a pilot valve (8, 9), embodied as a solenoid valve and assigned to the main valve (6, 7), which are arranged in a valve housing (2, 2) subdivided by a plane of division (10), into a main housing (11, 11) and a housing cover (12). For fixing the housing cover (12) on the main housing (11, 11) a bracket element (62.1) is fixed to the main housing (11, 11) and bears with a largely planar pressure plate (63) generating an elastic prestressing force on a planar outside wall (64) of the housing cover (12) oriented parallel to the plane of division (10) of the valve housing (2, 2).

When a brake system on a commercial vehicle, lateral acceleration and/or yaw of the vehicle are monitored and compared to a first predetermined threshold. If the first predetermined threshold is exceeded, a precharge command is sent to the brake system to precharge one or more air chambers by temporarily deactivating a modulator valve and activating an antilock traction relay valve in order to charge the air chambers up to a level permitted by the modulator valve. Upon detecting a panic braking event, a command signal is sent to the brake system to release the precharged air to facilitate braking.

A valve unit (1) for modulating pressure in a compressed air braking system includes a brake pressure input (3), a brake pressure output (4), and a purge output (5), an inlet valve (6) and an outlet valve (7), both configured as a diaphragm valve, and respective precontrol valves (8, 9), which are each configured as a 3/2-way solenoid valve. For effective sound damping of the compressed air emerging into the environment when the outlet valve (7) is open, the valve unit (1) at the purge output (5) has a silencer (75) with a largely cylindrical silencer housing (76) with an inlet opening (77), a calming chamber (78), a large outlet opening (79) and a silencer insert (80.1) arranged upstream of the outlet opening (79) inside the silencer housing (76). The silencer is air-permeable and sound-deadening and attached to the base housing (11) with base walls (83, 84).