HOSE ASSEM. 7V3638 - Caterpillar

Material Height Sensors
Illustration 15 g02142190
Rear of Machine, Right Side of Auger (26) Protective housing (27) RodThe right paddle sensor is enclosed inside protective housing (26) and is connected by rod (27) to a material height paddle (not shown). These components are located on the right side of the machine. The left paddle sensor is located in the same area on the left side of the machine.During paving, the material height paddle rests on the asphalt at the outboard side of the auger. The greater the amount of asphalt at the end of the auger, the farther the paddle is pushed toward the outside of the machine.The right paddle sensor provides pulse width modulated signals to terminal "J2-25" of the machine ECM. The left paddle sensor provides pulse width modulated signals to terminal "J2-24" of the machine ECM. The machine ECM compares the input signals from the paddle sensors to the input signals from the material height dials. Then, the machine ECM determines if the actual amount of asphalt in front of the screed matches the desired amount (setpoint). If the actual amount of asphalt is greater than the desired amount on either side of the machine, the machine ECM stops the corresponding conveyor and auger motors. If the actual amount of asphalt is less than the desired amount, the machine ECM operates the conveyor and auger motors at varying speeds. In this case, the speed of the motors is proportional to the distance that the paddle is from the setpoint.
Illustration 16 g02142191
Right Side of Screed (28) Material height sonic sensorMaterial height sonic sensors (28) (right shown) are mounted on the left and right sides of the screed. These components can be used in place of the material height paddles.The material height sonic sensors operate by emitting sound waves and then monitoring the time required for the waves to reflect off the asphalt pile and return to the sensor. The elapsed time is proportional to the amount of asphalt present.The machine can also be equipped with optional conveyor sonic sensors (not shown). The machine electronic control system automatically detects the conveyor sonic sensors. For machines equipped with the conveyor sonic sensors, machine ECM (17) controls the conveyors independently in order to maintain the desired material height at the rear of the conveyor. For machines without the conveyor sonic sensors, the machine ECM controls the conveyor and auger simultaneously in order to maintain the desired material height at the rear of the screed.Hopper Door Switch
Illustration 17 g02142193
Front of Machine (29) Hopper door switchHopper door switch (29) is located behind the hopper doors (shown open), at the front of the machine.Hopper door switch (29) is a normally open proximity switch. The position of this switch is monitored by the machine ECM. When the hopper doors are closed, the switch is closed and the machine ECM detects a ground at terminal "J1-33".