BOMAG Milling Pull wire sensor(05940023)04-21-30070) string sensor For PM200 Milling Bomag

1. Function and Purpose

Its core function is to accurately track an external taut wire reference line (Stringline) and convert mechanical displacement into electrical signals transmitted to the main controller, thereby automatically adjusting the depth of the milling drum to ensure the milled road surface fully meets the designed elevation, slope, and smoothness requirements.

Mechanical Sensing: The sensor is equipped with a precision mechanical arm or roller. During operation, this component rests directly on the wire rope (Stringline) serving as the absolute reference.

Signal Conversion: When the machine's height relative to the wire changes (e.g., due to unevenness of the existing road surface causing the body to lift or lower), the mechanical arm moves accordingly. The sensor's internals (typically a precision potentiometer or encoder) convert this tiny mechanical displacement into a proportionally varying electrical signal.

Depth Control: The main controller receives this electrical signal and compares it to its internally set target value. Upon detecting any deviation, the controller immediately issues commands to adjust the milling drum's hydraulic cylinders for real-time depth compensation, ensuring consistent milling depth.

2. Operation Method and Characteristics

This is a contact-type, mechanoelectronic sensor:

Contact Type: Must be in physical contact with the wire reference line to operate.

High Precision: Since the wire reference line provides a fixed and precise absolute height reference, this method is the most accurate and reliable of all leveling methods. It is commonly used in projects requiring extremely high smoothness, such as highways and airport runways.

Direct Measurement: Directly measures the machine's position relative to the reference line, rather than measuring the distance to the road surface, thus unaffected by the condition of the milled surface.