HMC Built for Speed to Aid High-Volume Production

Absolute Machine Tools Inc. sells and services the Tongtai SH-4000P HMC, a high-speed machining center designed for high-volume production. The machine has an XY traveling column design in which the pallet moves in the Z direction. The automatic pallet changer (APC) is located in front of the machine to provide easy access and to reduce idle time. The APC is a rotary-type pallet changer that exchanges pallets in 5.9 seconds. For pallet rotation in the machining envelope, a full-contouring B axis precisely indexes the pallet every .001 degree, and a hydraulic clamping mechanism is used to clamp the pallet in place for repeatability. The B axis is high-speed, with a 90-degree index time of 0.5 second. 

The  LHL/LubeUSA grease lubrication system is standard for ways and ballscrews so there is no coolant contamination or waste oil. The 40-mm (1.57"-diameter) ballscrews have a double-nut, pre-loaded and pre-tensioned design, enabling a traverse rate of 2362 inches per minute. High-speed acceleration reduces non-cut time. The Absolute Pulse Coder servo system does not require a zero return. A standard rear discharge chip-removal system includes a center trough design with high-volume chip wash for efficient chip removal. A combination dual level caterpillar-type conveyor is standard.

The SH-4000P has a high-power integral spindle with 15,000 rpm and spindle acceleration from 0–7000 in 0.48 second and 0–15000 in 1.9 seconds. Deceleration from 12000 rpm to stop is 0.8 second. The spindle produces 50 HP peak, 35 HP in high and 25 HP in low while producing 184 ft./lbs of peak torque at only 980 rpm. To enhance milling capabilities, a Big Plus dual contact spindle is standard. Air and oil mist are used for spindle-bearing lubrication to increase spindle life.

The Sankyo RollerDrive gearbox arm mechanism gives the standard 60-station automatic tool changer (ATC) a tool-change time of 1.4 seconds. Average chip-to-chip time is 2.6 seconds. A FANUC OiM-F conversational control is standard and available with a full range of high-speed machining options for mold detail and electrode machining.