Special Design For Cutting Threads On A Metal Lathe - CH61200L CNC turning center with C axis – Premach

Brief instruction

This machine is mated with C axis, feed X and Z axis, three axis can be linkage and move together with multi-function and high cutting efficiency.
Mated with SIEMENS 828D CNC system.
Two gears of spindle speed, and stepless speed within gears, hydraulic gear shift, consistent line speed cutting. Main spindle motor is SIEMENS 37KW A.C. servo motor, decrease speed and increase torque by gears, spindle speed is 5-200rpm.
C axis is indexed by high precision AC servo motor, and hydraulic automatic locking, and using circular grating for actual position detection; X axis adopts SIEMENS AC servo motor driven and high precision ball screw pair to realize lateral movement, Z axis adopts SIEMENS AC servo motor drive high precision worm reducer to move longitudinally, both X, Z axis are equipped with the grating for actual position detection, closed loop control, with good positioning accuracy and repeat positioning accuracy

use of the machine

This is a high efficiency cutting machine, suitable for cutting cast iron, steel and non-ferrous metal processing with high-speed steel and hard alloy tool. It can be turning external circle, end face, cutting groove, cutting off, cutting internal hole, milling keyway, milling spiral groove, drilling and tapping.
Sketch map of the workpiece:

Milling keyway 

parameter and capacity

Main structure

1)bed
The bed is a floor type bed with a width of 1100mm and a high strength resin sand casting. The material is HT300. The bed has the advantages of strong rigidity, large bearing capacity and good stability
The guide way is one mountain and one flat structure, the hardness of guide way is above HRC52, thick hardening depth is helpful to be ground.
The inner cavity of the bed body is provided with W shaped reinforcing rib, which greatly strengthens the rigidity of the machine bed and reduces the deformation due to bearing weight.
After the aging of the bed casting, it can remove the residual stress in the casting, and reduce the release of the residual stress in the processing and use of the machine.
There are sloping and arched holes on the rear of bed that are used for chip removal. The chip, coolant, lubricating oil and so on are removed directly into the chip tray. So the chip cleaning is convenient, and the cooling liquid can be recycled

2)Headstock
The spindle adopts three-point support, with the front end as the fixed end, the middle and rear ends as the traveling end, the front and rear ends as the main support, and the middle as the auxiliary support. The axial positioning is set at the front end of the spindle, so that the spindle extends backward after being heated, eliminating the impact of the thermal extension of the spindle on the accuracy of the machine tool.
The main drive of the lathe is realized by Siemens AC spindle motor through belt pulley, gear and four-stage hydraulic automatic shift. The constant torque range of the spindle is large and constant linear speed cutting can be realized. The spindle bearing is a special bearing, with high precision and strong rigidity.
The headstock is lubricated by strong oil, and the headstock gears and bearings are lubricated by a special oil pump. The front end of the spindle adopts the double sealing structure of labyrinth and slot, which can effectively prevent oil leakage and foreign objects from entering the headstock.

3)：tool post
Adopt German SAUTER 8 position horizontal turret 0.5.473.532.8, this turret has function of cutting external circle, end face and threading as well as milling, drilling and tapping. This turret is driven by SIEMENS servo motor installed on it, and mated with the following accessories.

4)Z and X axis：
Diameter of ball screw of X axis isφ40×5, Z axis is driven by rack and gear, teeth module is m=5, and z axis adopt full closed loop control by grating ruler feedback
5)Tail stock
Tailstock consist of upper part and bottom part, quill and quill center line adjusting organization are installed in upper part. The travel of tailstock is driven by motor. The quill of tailstock can rotate.
6)lubrication system
The lubrication of bearings in headstock, gears and bearing in headstock and other cases is supplied by the special pump, lubricating of bearings of ball screw and each lubricating point of the machine adopts intermittent and concentrative lubrication, and lubrication time is adjustable, so that it effectively prevents to waste lubricating oil, and can effectively improve the machine’s dynamic response and the service life of the guide way and ball screw.
hydraulic system
Hydraulic system is used for automatic change of spindle speed and forced coolant of gears in headstock as well as automatic lock of C axis.
7)C axis
The C axis is driven by a servo motor, can automatically switch to the transmission mode of spindle and C axis, the rear of spindle is fitted with high precision circular grating of C axis and brake damping mechanism. With whole closed-loop measurement system.

Accuracy of machine