Cold pilger tube mills for ductile materials

 

 

This type of the mills is intended for rolling tubes from ductile materials on the base of copper or aluminum and others materials with breaking point in initial state up to 500 MPa. Mill of "DUO" type is recommended for production of these tubes.

 

Furthermore, reinforced "DUO" design is used for rolling of hard deformed materials with breaking point in initial state up to 1000 MPa.

 

CPM 6-20 commissioning tests at the customers site.

 


Technical characteristics are shown below:

Technical characteristics of CPM for rolling tubes of ductile materials

Offered 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
Single-strand mills
CPM 60 60 16-50 1-5 800 180 200-800* 110
CPM 80 80 25-60 1-10 960 160 150-600* 160
CPM 110 110 40-90 2-12 1160 120 100-600* 250
Double-strand mills
CPM 2-60 60 16-50 1-5 800 140 300-1200* 160
CPM 2-80 80 25-60 1-10 960 120 250-900* 200
CPM 2-110 110 40-90 2-12 1160 100 150-800* 250


* depending on rolling pass schedule and quality requirements


Design features of CPM main units for rolling the tubes of ductile materials

 

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 coil reeller.

Working stand travel drive. Working stand travel drive 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.