Caterpillar has announced the availability of the PM620 and PM622 cold planers high-production, highly maneuverable half-lane milling machines that perform controlled full-depth removal of asphalt and concrete pavements in a single pass. Operating weight for the PM620 is approximately 33,330kg (73,260 lb), and for the PM622 approximately 33,900 kg (74,580 lb).
The PM620 and PM622 are powered by a Cat C18 ACERT, a turbocharged, six-cylinder diesel engine that provides 470kW (630hp) of gross power. The C18 engine meets U.S. EPA Tier 4 Final and EU Stage IV emission standards and is iso-mounted to reduce vibration and increase operator comfort.
The Automatic Engine Speed Control feature allows the engine to optimize output to match the load, reducing excessive fuel consumption and wear on the engine. The turbocharged air-to-air aftercooling system provides high horsepower with increased response-time while keeping exhaust temperatures low, which generates significant improvements in airflow. This increases efficiency and reduces emissions. An on-demand variable speed fan draws ambient air from the top of the engine hood and through the cooling package, keeping the engine compartment cool. Heated air exits from the rear of the machine, directed away from the operator’s station for greater operator comfort.
The PM620 and PM622 utilize a four-post design. The leg posts feature an auto-leveling function that provides smooth height adjustment without stepping.
The machines are fully hydrostatically driven by two variable displacement propel pumps supplying oil to variable displacement motors on each track. Drive motors are piston-type and automatically control displacement to provide maximum torque for work or greater speed for moving around the job site. A propel lever/steering joystick provides infinite control of the travel speed within the range.
The machines have a robust propel system with a diagonal cross flow design that provides exceptional traction. The pumps drive opposing track motors, front to back and side to side, to ensure the machine has power across the center of gravity of the machine. In extreme conditions, automatic traction control minimizes slippage by providing more power to tracks that grip.
There are several automated functions to simplify operation. The operator’s platform has a ‘hold’ button to stop the machine and pause various functions while making truck interchanges or job stops. It returns to previous working speed and functions when deactivated. There is a speed limit to allow the operating speed to set to ensure consistent operations.
The machines are equipped with position sensing cylinders in the posts and hydraulic systems, providing basic machine function improvements such as service height indications and rear leg auto-stop. It also enables the optional Cat Grade Control system to include additional capabilities.
The drive tracks are based on durable, proven Caterpillar designs and components. Track tension automatically adjusts to ensure optimum operation. Four-mode steering is standard. An electronic control module processes inputs from the sensors on the front and rear tracks along with input from the steering selector controls. It provides precise simultaneous track movement in the cab and coordinated steering modes and automatically realigns the rear tracks to center when the front-tracks-only steering mode is selected. In the coordinated mode, the inside turning radius is a tight 2m (6ft 5in) providing exceptional maneuverability in confined spaces.
A true-tracking alignment function provides greater steering precision, smoother cornering and reduced track wear. This function makes small adjustments to the alignment of individual tracks to ensure that the tracks are travelling in the optimal direction to make the desired maneuver without dragging a track or shorting a radius. This extends track pad and undercarriage component life.
August 5, 2016
