La description
Mandrel Connecting Machine is one of important
dedicated equipment in seamless pipe mill. Its purpose is
to carry out assembling or
disassembling of a complete mandrel composed of working length,
extension length and tail piece by screwing or unscrewing
operations.
1.
Features
As compared with other
competitor’s equipment of same kind, the outstanding particulars of our machine are
outlined as follows:
1) Main
tongs (rotating clamping chuck) is driven by a five pointed star
type great torque hydraulic motor and reducing gears, being
simple in structure and reliable in operation, as distinct from
other machine, say Italian Lazzari one, that rotating
clamping chuck is driven by means of pneumatic clutch-brake group
and reducing gears.
2) The
component to be screwed is automatically clamped in the main
tongs (rotating clamping chuck) when the main tongs (rotating
clamping chuck) rotates, and automatically slack off when
reverse rotating, as distinct from Italian one with hand-operated
rotating chuck.
3) The
component to be crewed is clamped or slack off in the back tongs
(stationary chuck) by means of pneumatic cylinder, as distinct
from Italian one, where the component to be crewed is clamped
without rotation by a stationary chuck-hydraulically
operated
4) The
mandrel and its extension length are supported by means of idle
roller conveyor, that can be positioned according to diameter
(height is adjustable).
5) Insertion
or removal of the mandrel and its extension length in or from
this machine are performed by means of handling equipment, which
is composed of motorized vertical biconical rolls.
2.
Constitution
A
Mandrel connecting machine is basically composed of three parts:
main machine including main tong & back tong, roller
way and output roller way. Auxiliary equipment includes hydraulic
power unit, electric cabinet and operation console,
etc.
3.
Function
3.1
The roller way is used for supporting and positioning of mandrel
and relative extension length. The roller way is composed of a
series of driven rollers and a pull-rod system. The height of
rollers is adjustable for the purpose of positioning. The up and
down movement of rollers is carried out by a left side motor-gear
reducer set driven lead screw.
Driven rollers are all supported on journal
bearings, being able to turn even by a bit force.
3.2
Safety stoppers are fixed outside the entrance of roller way to
prevent mandrel and extension length from deviation owing to
maloperation of operator during lift or putting
down.
3.3
At the entrance of roller way a pair of leading pressure rollers
are vertically fitted whose rotation is driven by two independent
motor-reducer sets. A mandrel or extension length is moved
forwards to correct screwing or unscrewing position
by means of rotation of the leading pressure rollers. The
horizontal central line of leading pressure roller, horizontal
central line of mandrel and the central line of main tongs are
all kept in a line. The cylinder linked to pull-rod mechanism
will make the leading pressure rollers in harmony with mandrel,
and exerts necessary force for movement of mandrel.
3.4
At the exit of roller way another pair of leading pressure
rollers is installed, which is also equipped with supports and
gearing whose constitution is the same as one at
entrance.
3.5
In driven rollers of output roller way, motor-driven supporting
rollers I and II are fitted, which act as sustaining while a
mandrel rotates for connecting or disconnecting. The up and down
movement of supporting rollers I and II is carried out
by means of a right side motor-gear reducer set driven lead
screw, thus resulting in positioning.
3.6
Safety stoppers are also fixed outside the exit of every roller
way whose function is same as one outside entrance.
3.7 A
hydraulic power unit is provided to power the hydraulic motor of
the main tongs.
3.8
An electric cabinet and an operation console are provided to
conduct semi-auto electric control and operator’s reasonable
intervention
4.
Configuration & Performance of Main Machine
The
main machine consists of main tongs, back tongs, pneumatic
cylinder-pull-rod mechanism, double supporting roller mechanism
and single supporting roller mechanism.
4.1 Main Tongs
4.1.1
Working Principle
The
main tong is driven with a hydraulic motor, being able to rotate
forwards or backwards. The power output from hydraulic motor
transfers to a *-buterfly shape clamping mechanism by the way of
gear & lazy pinion-big gear-inner geared ring.
4.1.2
Clamping Principle
*-buterfly shape self-aligning principle is
adopted in design of the clamping mechanism. A planet gear frame
is fixed on the inner geared ring of a big gear. A certain
friction is exerted on the planet gear frame by a brake placed on
the case. While the big gear rotates the three planet gears in
the planet gear frame will follow rotating through inner geared
ring drive, thus driving revolution of *- butterfly shape cams
and tightly clamping a mandrel. If torque is greater than
friction exerted by the brake, the planet gear frame, 3 planet
gears,*- butterfly shape cams and the big gear will all
together rotate, thus performing screwing or unscrewing
operation.
A
piece of tong teeth is fixed on every cam. 3 pieces of tong teeth
for 3 cams are evenly arranged on circumference and tightly seize
mandrel. As torque of tongs varies the clamping force will be
directly proportional variation to torque. The greater the
torque, the deeper the tong teeth seize. Vice versa. The design
of the clamping mechanism ensures minimum damage to work
piece(component)incurred from tong teeth under the condition of
required torque.
4.1.3
Turns of Measuring
The
friction drum is fitted with a geared ring, which is graduated
into one tooth for every 6°and installed with a electro-spectral
pulse transmitter. While the friction drum rotates as planet gear
frame numbers of screwing turn will be calculated on
the principle of one tooth to one pulse. numbers of screwing
turnï¼n×1/*0（n-
numbers of pulse. Measuring of pulse and calculation of turns are
automatically fulfilled and displayed by a computer for operator
reference.
4.2Back Tongs
4.2.1Drive and Clamping Principle
The
clamping principle of back tongs, basically, is similar to the
main tongs. What differs with the main tongs is that the case of
back tongs is stationary, and the inner geared ring inside the
case and 3 planet gears are geared. The revolution of planet gear
frame is driven by a back tongs’ cylinder. As a result, 2 planet
gears rotate, approaching towards work piece or leave away to
fulfill clamping or slackening operation. The initial clamping of
back tongs is carried out by a pneumatic cylinder, as against the
initial clamping of main tongs performed by
brake.
4.2.2
Torque Measurement
The
floating back tongs are fitted with a torque transmitter. On the
principle of “force multiplied by force arm equals torque” torque
value is automatically calculated and dynamically displayed by a
computer.
4.2.3Travel of Back Tongs
The
travel of the back tongs is driven by a pneumatic cylinder for a
certain distance (stroke) . Adjust the back tongs to initial
position prior to screwing. When you set about unscrewing
the piston rod of cylinder retracts maximizing the space between
main tongs and back tongs. In screwing or unscrewing operation
the back tongs move back and forth as mandrel. At this time both
of air intake and exhaust are open to air, so the back tongs are
under floating condition.
4.3Cylinder Pull-rod Mechanism
The
cylinder pull-rod mechanism is provided with supporting rollers,
furthermore its both sides are linked to supporting rollers of
mandrel. Before the beginning or after completion of screwing or
unscrewing operation the cylinder piston retracts, central lines
of the front and the rear supporting rollers of mandrel being in
same line. In screwing or unscrewing operation the cylinder
piston reaches out when the central line of rear supporting
roller( piston rod end) of mandrel is lower than the central line
of supporting roller of entrance roller way, the rear supporting
roller of back tongs getting off mandrel. In screwing or
unscrewing operation the clamping end of main tongs rotates
together with mandrel, nevertheless the supporting roller is
unable to rotate together with mandrel. Therefore the supporting
roller of back tongs has to get off mandrel.
4.4Double Supporting Roller
Mechanism
A
double supporting roller mechanism is placed between the main
& back tongs so as to increase supporting points. Its
structure is basically similar to the single supporting roller
mechanism except for one more supporting roller. On the principle
of parallel motion (parallelogram) the height of central line for
the both supporting rollers is always kept same, they moreover
are at equal height to central line of single supporting roller.
They are all on the same level.
4.5Single Supporting Roller
Mechanism
A
single supporting roller mechanism is respectively placed outside
the main tongs and back tongs.
4.6Control System & Operation
Console
4.6.1
An electric cabinet and a local operation console are provided
for ease of control and operation.
4.6.2
The electric cabinet includes one PLC for control mandrel
connecting system.
4.6.3
The driving motor for leading pressure rollers is of frequency
converter being able to automatically vary revolutionary
speed.
4.6.4
The Machine will automatically stop screwing operation according
to torque setting. Operators also can carry out interference if
necessary.
4.6.5
Measuring systems for torque and turn of revolution are set in
the control system. Data measured are automatically displayed and
stored by a compute, on which operators may make
control.
5.
Technical Parameter
The machine is customized on the basis
of requirements of Buyers. Three most important parameters of the
machines that have been produced are listed as
below.
|
Model
|
Diameter of
mandrel
|
Max. torque
|
Installed power
|
|
MM**0/**0
|
Ф***-Ф**0 mm
|
**0 KN.m
|
*7 KW
|
|
MM**0/*0
|
Ф***-Ф*0
|
*0 KN.m
|
|
|
MM**0/**0
|
| Pays: |
China |
| N ° de modèle: |
Model MM
|
| Prix FOB: |
(Negotiable)
Obtenir le dernier prix
|
| Localité: |
- |
| Prix de commande minimale: |
- |
| Commande minimale: |
- |
| Packaging Detail: |
Container |
| Heure de livraison: |
- |
| Capacité de Fournir: |
- |
| Payment Type: |
L/C |
| Groupe de produits : |
- |
