摘要:
An installation for the production of pressure has three operating states corresponding to a delivery operation, an idle operation, and a partial delivery operation. The installation contains at least two compression chambers in at least one compressor, each chamber being assigned at least one switchable inlet valve. In the delivery operation, the switchable inlet valves act as check-valves that allow pressure medium to flow into their respective compression chambers. Each compression chamber also contains at least one outlet check valve through which compressed pressure medium flows out to a pressure consuming system in the delivery operation. Each switchable inlet valve also has an idling position that allows pressure medium to flow into the applicable compression chamber and back out again without being substantially compressed. In the idle operation of the installation, each switchable inlet valve switches to its idling position. In the partial delivery operation, one of the switchable inlet valves independently switches to its idling position, while the other inlet valve remains in its rest position, thus resulting in only partial delivery of the pressure medium to the pressure consuming system.
摘要:
A level control system for motor vehicles having pneumatic springs which function in accordance with the vehicle load. A specified distance is normally maintained between the vehicle body the vehicle axle. This distance is maintained by charging or discharging the pneumatic springs. The level control system includes an air dryer and a pneumatic relay type of controllable discharge valve having a relatively large cross-sectional port by which the air dryer is connected to the atmosphere. The discharge valve operates against a spring return force. The magnitude of the spring return force corresponds to a preselected minimum pneumatic spring pressure. The system counteracts an icing action of the discharge valve and prevents an unintentional and complete discharging of the pneumatic springs.
摘要:
The inventive device controls the trailing axle of a vehicle having at least two rear axles, wherein at least one rear axle is a driving axle. Pressure fluid chambers, mounted on both the driving and trailing axles, support the vehicle structure. Their pressure is varied to raise or lower the vehicle structure depending on the vehicle load and road conditions. The inventive device further comprises a first valve arrangement and a second valve arrangement. The first valve arrangement selectively connects the pressure fluid chambers of the driving axle to a compressed-air supply, to a pressure fluid sink, or isolates them. The first valve arrangement has a first and a second valve. The first valve is a 3/2-position valve actuated by a first solenoid. The second valve of the first valve arrangement is a 2/2-position valve actuated by a second solenoid. The second valve arrangement is a 3-position valve actuated by a third solenoid. The 3-position valve is controlled by cooperation of the third solenoid and a control pressure. This selectively connects the pressure fluid chambers of the trailing axle to the pressure fluid chamber of the driving axle, or to the pressure fluid sink. Alternatively, the 3-position valve isolates the trailing axle pressure fluid chambers. The control pressure is taken from the pressure fluid output of the first valve.
摘要:
A compressor with a cylinder head (33, 29) comprises a lower cylinder head section (33) and an upper cylinder head section (29) connected to each other. A seal (12) is provided between the faces of the lower cylinder head section (33) and the upper cylinder head section (29) facing each other. A suction space (31, 25) and a pressure space (10, 17) as well as a suction valve (32, 4) and a pressure valve (5, 7) are installed in the cylinder head (33, 29). A compression space (3) of the compressor is connected by the suction valve (32, 4) to the suction space (31, 25), and by the pressure valve (5, 7) to the pressure space (10, 17). The suction space (31, 25) is also connected by a suction connection (71) to the atmosphere, and the pressure space (10, 17) is connected to a consumer by a pressure connection (18) to a source of pressure. In order to achieve efficient transfer of heat in the cylinder head (33, 29), a wall-like part (76), made of a material with good heat transferring properties, is provided at least in the pressure space (10, 17) to subdivide the pressure space (10, 17) of the cylinder head (33, 29) into a first pressure chamber (10) and a second pressure chamber (17). The first pressure chamber (10) and the second pressure chamber (17) are connected to each other by a passage opening (77) located in the wall-like part (76). Desirably, the suction space (31,15) is subdivided into first and second suction chambers (31,15) by a U-shaped part (79,80) having a second passage opening (78).
摘要:
A level control arrangement for motor vehicles having air springs which are functionally responsive to the vehicle load. A predetermined distance of the vehicle frame from the vehicle axis can be maintained by charging or discharging the air springs. The control arrangement includes a safety valve which can be controlled by the pressure in the air springs. When the vehicle is overloaded, or if a malfunction occurs in the control apparatus of the level control arrangement, the safety valve limits the pressure in the air springs to a preselected maximum safe pressure.
摘要:
An apparatus for the generation of compressed air is disclosed, where the supply of air from the compressor (1) to the user (6) is interrupted in case of preset user-side pressure. This apparatus prevents a freezing in case of low ambient temperatures in the pressure lines in which condensed water has formed. A temperature sensitive switching device (14, 29) responds to the actual ambient temperature. The switching device (14) does not stop the compressor (1) in case of a preset user-side pressure and in case of a falling below of a preset ambient temperature. The compressor (1) carries then the warmed-up air through a region of the device before discharging it into the surrounding atmosphere. The device is particularly suited for compressed-air generation plants in motor vehicles which are adapted to be used in cases of low ambient temperatures.