摘要:
An electronic interface custom integrated circuit which provides interfacing between micro-controller devices and field effect transistors in truck or car anti-lock braking systems for controlling solenoid valves to modulate the pressure in the brake chambers or brake cylinders. The interface circuit includes built-in diagnostic and safety features including fault protection interlock, safety interlocks, status indication outputs and a special purpose analog output for enhancing the performance of anti-lock braking system electronic control units.
摘要:
An electronically controlled compressed air system (10) includes an air dryer (16) which dries compressed air before the compressed air is communicated to a reservoir (26). The air dryer (16) includes a desiccant (18) which is purged by using air stored in the reservoir (26). A pressure transducer (13) is installed on the reservoir (26) and transits an electrical signal, indicative of the pressure in the reservoir (26) to an electric controller (11). Electric controller (11) transmits signals at various selected pressure levels to solenoid value (28) to control loading and unloading of the compressor (12), to solenoid valve (36) to control purging of the air dryer (16), and to the warning light (40) to alert an operator of a low air pressure condition. The valve (36) is operated to permit purging only when the compressor (12) is unloaded and only until a reservoir pressure is reached which is a predetermined pressure drop below the reference pressure level at which the compressor (12) is unloaded, whereupon purging is terminated.
摘要:
A remote fault indicating unit (12) for an electronic system, such as a vehicle adaptive braking system, includes a series of visual indicators, such as light emitting diodes (50-59), on one surface of the housing and a computer serial port connector (13) for use when troubleshooting is done with a PC (18) equipped with the appropriate software. Each of the indicators (50-59) is activated in response to a predetermined malfunction sensed in the system, such as a defective speed sensor, defective modulator, or a defect in the electronic circuitry. The indicators (50-59) are reset with a switch (15) when the system is repaired. When the reset switch (15) is activated, all of the indicators (50-59) flash on and are then turned off. The reset switch (15) can also be activated for a longer period of time changing the ECU (14) configuration. A non-volatile RAM stores, in the ABS ECU (14), suspected problems sensed by the antilock system when the system is powered down, so that all malfunctions are again indicated immediately when the ABS is powered up.
摘要:
A method and apparatus for graphically monitoring and controlling a vehicle anti-lock brake system is provided. Multiple types of graphical data concerning different aspects of the anti-lock brake system are simultaneously displayed to a technician. Output lights provided as a part of the vehicle anti-lock brake system are graphically emulated on a display terminal. Various vehicle anti-lock brake system components, such as a retarder relay, modulators, indicator lights, and the like, are controllable through a graphical user interface, and both the presence and location of anti-lock brake system faults is graphically indicated to a technician. The method and apparatus also include graphically displaying real-time or previously recorded wheel speed data for all or selected individual wheels connected to a vehicle anti-lock brake system, alone or in combination with other graphical data, and for saving real-time wheel speed data for subsequent review. Communications data sent to and from the anti-lock brake system electronic control unit is also graphically displayed to a technician.
摘要:
An air dryer and reservoir assembly for providing compressed air from an air compressor (20) on a heavy motor vehicle which includes an air dryer (14) connected to receive compressed air from the air compressor (20) and a secondary reservoir (12), including an integral purge volume (34), for storing compressed air which passes through the air dryer (14), with the air dryer (14) and the secondary reservoir (12) being securely attached to a housing (16) to form an air dryer reservoir module (10). A primary reservoir (18) for storing compressed air from the air dryer (14) is located remote from the air dryer reservoir module (10). A pressure equalizing mechanism (57) is disposed between the primary reservoir (18) and the secondary reservoir (12) for keeping pressure in the two reservoirs (12,18) equal. Components located within the housing (16) control air flow between the air dryer (14) and the primary and secondary reservoirs (18,12) and also monitor the pneumatic brake system circuits fed by the primary and secondary reservoirs (18,12).
摘要:
An pneumatic system (10) for a tractor trailer truck (6) which increases compressed air flow to the trailer reservoir (52) whenever the tractor (7) is parked. This decreases the time it takes to charge the trailer reservoir (52) to a sufficient pressure to release the trailer brakes allowing the truck (6) to move. In normal over the road operation the trailer reservoir (52) is charged through a tractor protection control valve (14) which is mounted on the tractor dash. However when the tractor (7) is parked and a tractor park valve (12) which is mounted on the tractor dash is pulled out compressed air from the tractor secondary reservoir (42) is delivered with an increased flow rate to the trailer supply line (50). When the tractor park control valve (12) is pushed in releasing the tractor parking brake the trailer charging reverts back to charging through the dash mounted tractor protection control valve (14). Pulling the tractor protection control valve (14) out vents the trailer supply line (50) in both the fast and normal charge mode.
摘要:
A pilot operated relay valve (10) for an air pressure braking system includes a relay piston (16) which is responsive to the pressure at a control port (20) to open the valve (10) so that it's inlet port (38) is in free communication with it's outlet port (24). The relay piston (16) includes a balance orifice (26) which permits the outlet port (24) to communicate with the control port (20) to equalized or balance the pressure differential therebetween. A shut off valve arrangement (80,82) or a check value (90 or 92) is provided to shutoff or control flow through the balance orifice during rapid release modulation of the pressure signal for braking applied to the control port (20).
摘要:
An air supply system for a motor vehicle air brake system incorporating a desiccant type air dryer. The purge capacity of the air dryer is enhanced providing greater water and contaminant removable characteristics for the air dryer. The system incorporates a pressure reducing element and a control system for the system compressor causing air passing through the air dryer to be at a higher pressure than that necessary for charging the system reservoir. The higher pressure air supplied to the air dryer provides greater volumetric capacity for the purge volume of the air dryer. In this way an air dryer purge volume of a given size provides a greater purge capacity.
摘要:
An ABS modulator solenoid valve (10), having one electric solenoid (12), in which the valve control piston (14) has a passage (16) therethrough for balancing the pneumatic pressure on both ends (34, 36) of the control piston (14). One end (34) of the piston (14) is disposed in a closed piston chamber (32) while the other end (36) is positioned to contact and position a valve spool (40). The passage (16) extends between the ends (34, 36) of the piston (14). Piston (14) is biased by a spring (50) to a position within the piston chamber (32). When the solenoid (12) is de-energized the piston (14) remains in this position and variable air pressure, from an operator controlled brake valve (126), can be supplied through the valve (10) to a brake chamber (128) for operating the vehicle service brakes. During an ABS application the solenoid (12) is energized to overcome the inlet spring (50) bias and the piston (14) moves into engagement with the valve spool (40). The spool (40) is biased by an exhaust spring (52) to a position wherein the exhaust port (24) is isolated from the supply port (20) and the delivery port (22). When the solenoid (12) is fully energized the piston (14) engages the spool (40) and moves it to the exhaust position. When the solenoid is energized with a selected hold current the piston (14) engage but not move the spool (40) and the valve (10) is then in a hold position. Since the pressure on the ends (34, 36) of the piston (14) is balanced the force required to move the piston (14) to the hold position is relatively constant and not greatly effected by the pneumatic pressure at the supply port (20) or the delivery port (22).
摘要:
An improved relay valve (10) having a supply port (16), a delivery port (18), an exhaust port (20), a control port (17), a relay piston (14) controlling communication between the supply port (16), the delivery port (18), and the exhaust port (20) in response to a pneumatic signal applied to the control port (17) and including a passage (40) extending through the piston (14) to the exhaust port (20) for draining to atmosphere moisture and other contaminants which build up on the top of the piston (14). A diaphragm element (30) having a cylindrical protrusion portion (36) is disposed in the piston (14) above the passage (40) to act as a check valve and seal the passage (40) when a pneumatic signal is applied to control port (17). The diaphragm element includes a top resilient portion (32) which serves as a spring to open the drain passage when no signal is applied to control port (17). Two flat areas (34) are provided on the top resilient portion (32) which prevents the diaphragm element (30) from prematurely sealing the drain hole (40). The cylindrical protrusion (36) keeps the diaphragm element (30) properly aligned in the tapered bore (44) leading to drain hole (40). A retaining ring (42) keeps diaphragm element (30) within the bore (44).