Cold pilger mills "DUO"

 

 

Classic CPM design "DUO" with two working rolls and movable forced working stand is used for rolling of hard deformed materials with breaking point in initial state up to 1000 MPa. Furthermore, high-speed lightened version may be used for rolling tubes of ductile materials on the base of copper or aluminum and other materials with breaking point in initial state up to 500 MPa. 

 

CPM 6-20 commissioning tests at the customers site

 

CPM 10-45 commissioning tests at the customers site

 

Technical characteristics are shown below:

Standard mill sizes

Mill size	P A R A M E T E R S
	Maximum shell diameter, mm	Finished tube diameter, mm	Finished tube WT ,mm	Stand stroke, mm	Number of stand strokes per min, not more	Capacity, m/h	Main drive power, kW, not more
CPM 6-20	34	6-20	0,5-3	580	240	100-350*	110
CPM 10-45	63	10-45	1,5-6	640	200	100-300*	132
CPM 20-70	93	20-70	4-12	820	160	100-250*	160

* depending on rolling pass schedule and quality requirements

Arrangements. The mills are delivered in single strand and double strand performance. The mills are made with end face loading with two shell chucks and two mandrel rod chucks.

Such arrangement provides operation of the mill without stoppage for loading of the next shell into the mill. Rolling without stoppage provides uniformity of the tube quality and increasing of production capacity.

Working stand. Working stand of the mills is made accordingly to traditional rolling scheme with movable forced housing, with ring type dies, with one-way rack drive of rolls rotation. Racks are fixed in stationary frame pivotally. Constancy of gap in engagement with lead gears is provided with help of support rollers.

Feed section equipment. Set of feed section equipment includes the following:

- two shell chucks with guides;

- tooth-rack drives for chuck travel;

- two mandrel rod chucks;

- pusher between rod chucks;

- receiving trough and pusher guides connecting rod chucks between each other;

- mechanism of rod chucks (mandrel) travel;

- device for supply of lubricant through the rod.

Shell chuck. Shell chuck spindle is equipped with jaw- type clamp with drive from hydraulic cylinder. When moving the chuck in direction of working stand, jaw clamp holds the shell, when moving in opposite direction jaw clamp is opened. The spindle is rotated from individual electric motor controlled in step mode synchronized with movement of the working stand with help of code sensors.

The chuck travel is realized with help of rack gear, the rack of which is fixed on chuck frame. Drive of rack pinion is carried out from individual electric motor controlled in step mode, synchronized with working stand travel with help of code sensors. Value of travel is in the range of from 1 to 10 mm per one feeding cycle. When returning of the shell chuck into initial position, the travel speed is 0.3 – 0.4 m/s.

Mandrel rod chuck. Rod chuck spindle is made as three jaws clamp with drive from hydraulic cylinder. Jaws are equipped with comb-shaped lugs holding the rod with mandrel in axial direction in closed state and passing the shell through the chuck in opened state.

Spindle is rotated from individual electric motor controlled in step mode synchronized with working stand travel with help of code sensors.

Front and back clamps of the rod are connected between each other by guides of pusher between rod chucks and trough for shell centering.

Mandrel travel mechanism is made in the form of screw pare, nut of which is fixed on the rod outlet chuck body but screw is put into rotation by electrical motor through worm reducer.

Device for supply of lubricant through the mandrel rod into inner shell aria in front of mandrel is installed on rod outlet chuck face.

Under coordination with Customer, the mills can be delivered with maximum shell length of from 5 up to 15 m and with tables for receiving of finished tubes with length necessary for production requirements. Finished tube receiving table set can include fly cutting device for cutting of corresponding tube lengths and coiling machine.

Drive of stand/cassette movement. Drive of stand/cassette movement is made of planetary-crank type with rectilinear motion of crank with rotating counterweight balancing of dynamic forces and moments system that allows to decrease energy consumption significantly during mill operation.