Hydraulic Extrusion Presses: Presses used for the production of tubes, solid rods, hollow sections, wire, and cable sheathing in nonferrous metals

263 Pages·1961·13.61 MB·English

by  Ernst Müller (auth.)

Hydraulic Extrusion Presses
Hydraulic
Extrusion Presses
Presses used for the production of tubes,
solid rods, hollow sections, wire,
and cable sheathing in nonferrous metals
By
Ernst Miiller
Duisburg
With 189 Illustrations
Springer-Ver lag
Berlin/ Gottingen/ Heidelberg
1961
ISBN 978-3-642-53025-8 ISBN 978-3-642-53023-4 (eBook)
DOI 10.1007/978-3-642-53023-4
All rights reserred_ This book, or parts thereof, may not be reproduced ill any form withuut
written permission of the publisher
© by Springer-Verlag OHG_, Berlill!G6ttingeujHeidelberg 1961
Softcover reprint ofthe hardcover 1st edition 1961
Preface
The wide variety of hydraulic presses used for the manufacture
of tubes, cable sheathing, rods, profiles, and wire in nonferrous metals
has gone through an extraordinarily interesting development which
commenced about 50 years ago after the advent of high-tensile hot
working steels and has since adapted itself to the steadily growing de
mands of the metalworking industry. This development has especially
been promoted in Germany where many of the old presses are still in
use for the extrusion of rods and tubes in heavy metals, and lead, already
decades ago, to the construction of hydraulic presses which rank among
the largest equipment built for noncutting shaping of metals.
This book, therefore, draws in the main upon the German deve
lopment, giving an account of the advances made in extrusion technique
and press design and presenting to the reader the sum of the experience
gathered.
A great number of very instructive works dealing with the techno
logical aspects in the extrusion of metals and the results obtained in
metallurgical investigations has been published. These, it is true, contain
important reference material regarding the design of presses and press
tooling, but very few of them give a detailed description of the deve
lopment and calculation of the machines or the requirements to be met
by presses and tooling, so that the present book is to fill a gap in the
existing literature.
This volume not only brings a comparative description of presses,
press drives, press controls, auxiliary equipment, and tooling, but also
indicates details of design and calculation which are the result of prac
tical experience. In order to limit the scope of this book, such auxiliary
equipment as runout and cooling beds, extrusion pullers, material
handling equipment, stretchers, bar breakers, cable take-up stands, wire
coilers, etc., has been excluded. Special presses as used for cold extrusion,
extrusion of special alloys, etc., and steel extrusion presses will receive
separate treatment in a later, enlarged edition.
In his work the author has been generously assisted by many com
panies at home and abroad whose names are mentioned in the text and
to all of whom he extends his thanks. He is especially indebted to his
associates Dipl.-Ing. A. HERTL and Dd. E. LOHMANN who translated the
book. It is hoped that this volume will be accorded a good reception by
the metalworking industry and that it will supply valuable information
to all readers.
Duis burg, ~Iay 1961 E. Muller
Contents
Page
CHAPTER I: PRESSES FOR THE MANUFACTURE OF LEAD PIPES
AND WIRE ................................................... .
a) Lead Pipe Presses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
b) Lead Trap Presses. . . . . . . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
c) Lead 'Vire Presses ............................................ 9
d) Solder Wire Presses........................................... 11
CHAPTER II: PRESSES FOR THE MANUFACTt:RE OF LEAD AND
ALUMINUM CABLE SHEATHING.............................. 15
a) Lead Cable Presses for Charging of Liquid Metal. . . . . . . . . . . . . . . . .. 19
b) Lead- and Aluminum Cable Presses for Billet Extrusion. . . . . . . . .. .. 45
c) Continuous Lead- and Aluminum Cable Sheathing Presses Charged
with Molten Metal or Solid Billets ............................. 54
CHAPTER III: PRESSES FOR THE EXTRUSION OF PRO.FILES,
WIRE AND TUBES OF HEAVY- AND LIGHT METALS .......... 59
a) Horizontal Presses for Direct Extrusion. . . . . . . . . . . . . . . . . . . . . . . . .. 63
b) Horizontal Presses for Direct and Indirect Extrusion . . . . . . . . . . . . .. 90
c) Horizontal Combined Rod and Tube Extrusion Presses. . . . . . . . . . .. 95
d) Vertical Combined Rod and Tube Extrusion Presses ... " .......... 115
CHAPTER IV: RATING AND DESIGN RULES FOR ROD AND TUBE
EXTRUSION PRESSES ........................................ 127
a) Determination of Piston Forces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 127
b) Hydraulic Pressures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 138
c) Nomenclature of Tools and Tool Steels .......................... 139
d) Upsetting of Billet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 146
e) Piercing and Extrusion of Billet ................................ 146
f) Dies and Die-Holders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 149
g) Piercing Mandrels and Mandrel-Holders ........................ " 158
h) Containers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 164
i) Container Heating Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 176
j) Extrusion Rams .............................................. 181
k) Die-Carriers, Lateral Die Slides and Rotating Die-Holders .......... 182
I) Counterplatens ............................................... 186
m) Cylinder-Platens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 190
n) Columns ..................................................... 196
0) Movable Crossheads ........................ _. .... _. .. " ....... 199
CHAPTER V: DRIVE SYSTEMS .................................... 200
a) 'Yater-Hydraulic Pressure Pumps ............................... 204
b) Oil-Hydraulic Pressure Pumps ................................. 207
c) Pressure 'Vater Accumulators ....................... _. ......... 216
CHAPTER VI: HYDRAULIC CONTROLS ............................. 221
a) Hand-Lever Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 222
b) Motor-Driven Controls for Remote-Controlled and Automatic Opera-
tion ......................................................... 226
CHAPTER VII: PACKINGS, PIPINGS, VESSELS, AND FITTINGS .... 231
a) Packings for Stationary Components (Flanges etc.) ............... 232
b) Packings for Sliding Components (Pistons etc.) ................... 235
c) Pipings and Accessories ....................................... 238
CHAPTER VIII: PRACTICAL EXAMPLES ............................ 239
a) Stresses of a Hydraulic Cylinder (Fig. 185). . . . . . . . . . . . . . . . . . . . . . .. 239
b) Calculation of the Four Columns of a 2,500-Ton Tube and Rod Ex-
trusion Press (Fig. 186) ........................................ 243
c) Calculation of a Cable Sheathing Press .......................... 244
d) Calculation of a Tube and Rod Extrusion Press .................. 245
e) Dimensions and Shrinkage Allowances of a 3-Part Container (Fig. 188) 248
INDEX ............................................................. 254
Chapter I
PRESSES FOR THE MANUFACTURE OF
I,EAD PIPE S AND WIRE
The making of seamless lead pipes has been known for a long time
and may be traced back to the early days of constructing hydraulic
presses. Up to the present time changes in the technique of extrusion
have only been slight. The bore of the container and the mandrel rod,
being disposed in the center line of the container, form a hollow cylin
drical space which is filled with molten lead. The end of the container
bore is closed by a die, leaving open an annulus around the mandrel.
From the opposite end the lead is extruded - after solidification -
by a hollow ram, carrying at its nose a ring-shaped dummy block and
traveling over the mandrel; it issues from the annulus in the form of
a pipe.
The casting temperature of the lead is about 350°C. Transition from
the liquid to the plastic state takes place between 320 and 280 °C, where
as the extrusion of the lead is performed at a temperature between about
200 and 180°C.
The lead is supplied by the metallurgical works in the form of pigs
of about 99.8 per cent purity; from the melting kettle it is fed directly
to the container. Scr.ap lead is often added to the lead bath in order to
reduce the price of the pipes. Pure lead gives aboud 2% lead dross, where
as about 8% residue have to be taken into account in scrap lead. The
dross is collected and refined by chemical works. Larger quantities of
scrap lead are refined in a simple manner by heating it to a temperature
of about 450 to 500°C and skimming off the dross from the surface of
the metal.
For a long time there was an ever increasing demand for lead pipe
presses. However, this development came to a stop about fifteen to
twenty years ago, when pipes made of steel, non-ferrous and light metals,
as well as pipes of plastic or synthetic materials made their appearance
on the market.
Apart from the lead pipe press, there was also designed a series of
smaller presses, the most important types of which being employed for
the manufacture of curved lead pipes for use as bends or syphons, of lead
wire of round or profiled cross-section, and of tin solder wire.
1 ~IiiJler. Hydraulic
2 LEAD PIPES AND WIRE
a) Lead Pipe Presses
The first patent on a lead pipe press was granted to the Englishman
JOSEPH BRAMAH as early as 1797. The design of this press is shown in
Fig. 11). Liquid lead flows from a melting kettle a, which is heated from
beneath, through the valve c into the cylinder when the piston b moves
up. Piston b moving down causes the lead to be forced trough an annulus
formed by the tube-shaped
projection d and the
mandrel e. The mandrel
is secured to the kettle
casing which is provided
with several slots to allow
a for the passage of the lead
to the tube-projection. At
the extreme end of the an
nulus the lead solidifies and
issues in the form of a pipe.
Fuel gases are circulated
around part of the tube
projection d.
Decades had still to pass
since the publication of this
invention, until the first
hydraulic presses were con
Fig. I. BR.\)L\H'S lead pipe press structed and it was not
until 1867 that the lead
pipe press, as shown in Fig. 2, by the :Frenchman EAMON became known.
The principles of this early invention are still embodied in presses at
the present time.
In order to render possi.ble casting of the molten lead into the con
tainer, a lifting cylinder a with piston b for the lifting of the crosshead c
is arranged on top of the press. The nuts d are provided with bayonet
type threads. When changing tools, the crosshead f may be lifted with
the help of the clamps e. Casting of the liquid lead is followed by an
interval of five to ten minutes to allow for the solidification of the metal.
The extrusion temperature is about 210°C.
Fig. 3 shows the design of a modern lead pipe press. It has a bottom
cylinder platen a which is positively connected to the top counterplatenc
by means of four columns b. The plunger d runs in a bronze bush in the
cylinder and travels over a mandrel-bar holder e which is rigidly secured
in the base of the cylinder. Sealing of the plunger in the cylinder and on
1) PEARSON, C. E.: The Extrusion of Metals. London: Chapman & Hall 1953.
LEAD PIPE PRESSES 3
the mandrel-bar holder is ensured by leather- or vulcanized fiber packing
collari'! which may be removed after detaching a stuffing box flange and
a screwed union. The mandrel-bar f is screwed to the top end of the
mandrel-bar holder.
The plunger-head is guid
ed in its travel on the col
a
umns by a cross head g and
b
carries the hollow extrusion
ram h. The latter is secured
to the crosshead by means
of a flange and may be cen
tered by means of four la
teral screws. A dummy block
of forged high-tensile bronze
rests on the ram. Two draw
back cylinders i with sta
tionary drawback plungers j
being attached to the coun
terplaten, are arranged in
the plunger crosshead to d
obtain fast lowering speeds c
of the ram. The container k
e
is inserted in the counter
platen and secured by a
f
flange. Heat-insulated ducts,
to which is connected a gas
burner, are provided in the
counterplaten for the heating
ofthecontainer. Heating may
also be effected electrically.
The tooling consists of the
mandrel-tip, die, die-ring and
die-holder, the latter being
locked in the platen by two
opposed wedges 7. The wed
ges are adjusted via a spin
dle 'In with left- and right Fig. ~. I.end pipe press by H.nlo~
hand thread by turning a
hand wheel n. The emerging lead pipe runs over a pulley 0 to a coiling
drum. Pipes which cannot be coiled on account of their large diameter are
extruded vertically towards the head and cut off directly above t.hecounter
platen. The vertically extruded pipe is lifted by a crane (winch) as
the following hot pipe end cannot support the extruded pipe over the die.
I'
LE.-\D PIPES AND WIRE
-
- ":::-'~":::::::_-~m~~~~g~
~~~~~~~
The commercial weight of a pipe bundle is about 75 kg with a maxi
mum pipe diameter of about 60 mm. The bundle is lifted out of the coiler,
wrapped with straw ropes and prepared for shipment. For the purpose
of roughly determining the weight of a pipe bundle, the press is provided
with a dial gauge indicating the extruded weight in dependence of the
ram stroke.