FIELD OF THE INVENTION
The present invention relates to a die holder system for concurrently rotating die
and lubricating stirrer in wire drawing machines for drawing metal wires. More
pafticularly, the invention relates to an improved die holder system with a single
motor to concurrently operate a rotating die and a lubricant stirrer device to
enhance die life in machines drawing metal wires.
BACKGROUND OF THE INVENTION
Different methods are currently used in machines for drawing wires from wire
rods. The known methods have several technical problems to achieve the desired
parameters of the wires for example, physical properties, surface flnish. Some of
the problems that are commonly encountered are the improper cooling of the die
resulting in frequent die change, insufficient lubricant pick up on the wires,
lubricant cake formation hampering the smooth flow of the lubricants.
Numerous types of die box designs are available for example, fixed die holder
arrangement and rotating die holder arrangement, which are cooled by either
direct cooling or indirect cooting. Die is normatty made of Tungsten Carbide to
have desirable wear resistance propefi. The die sizes are maintained so that a
wire passing through the die achieves the desired size. During the drawing
operation, an extensive amount of heat is generated. The cooling process
ensures that the life of the die is maintained at an optimum level during wire
drawing operations. Insufficient die cooling results in frequent die replacements
which ultimately results in a drop in the production capability.
Rotating die box arrangements are expected to provide a consistent die wear, an
even product concentricity and flnish, lower drawing temperatures, better
lubrication on wires and increased drawing speeds. Reduced drawing
temperatures can reduce the die wear rates including the probability of forming
wire drawing lubricant soap cake. The commonly available rotating die box
arrangements are in general made out of a single casting containing a die
casing, and a soap lubricant box.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a rotating die box system
with improved die cooling facility.
Another object of the invention is to propose a rotating die box system which
allows stirring of the soap lubricant so that a uniform Grryover of the lubricant
with the wire is ensured.
A fufther object of the invention is to propose a rotating die box system which
enables utilizing the die box in any pass of a wire drawing machine.
SUMMARY OF THE INVENTION
According to the invention, there is provided a rotating die box with excellent
direct water cooling facility for die casing. To ensure that the soap lubricant is
canied with the wire properly, a modified lubricant stirrer has been developed.
The rotating die box with the soap box assembly can be fitted to any pass of any
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wire drawing machine by means of a replaceable guide roller/pulley fixing
arangement, and a height adjustment mechanism provided in the system.
BRrEF DESCRTPTTON OF THE ACCOMPANYTNG pRAWTNGS
Figure 1 - represents a sectional view of a rotating die box system with a die
holder device and a soap lubricant device, according to the
invention
Figure 2 - represents a side view of the rotating die box system with the soap
lubricant device and the die holder device according to the
invention
Figure 3 - represents a sectional side view of the rotating die box system with
the die holder device and the soap lubricant device according to the
invention
Figure 4 - represents elevation, plan and side views of a soap lubricant stirrer
of the soap lubricant device, according to the invention
Figure 5 - represents various positions for inserting and fixing a die inside a
die casing of the die holder device.
DETAILED DESCRIPTION OF THE INVENTION
Hereafter, the embodiments of the invention are illustrated generally in the
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accompanying figures.
Figure 1 shows sectional view of the rotating die box system with a soap
lubricant device and a die-box device. The inventive system basically consists of
two pafts, a soap lubricant device (8) and a die holder device (1). The lubricant
device holds a soap lubricant 15, which essentially consists of stearates of
Sodium or Calcium as per the wire drawing requirement. The die holder device 1
is attached to the lubricant device 8 by means of bolts 20. Guide rollers/pulley
(29) can be attached to the lubricant box (B) to properly guide the wire coming
from the previous pass. The soap lubricant (15) is continuously churned using a
soap lubricant stirrer 5. The details of the soap lubricant stirrer (5) can be ctearly
understood from Figure 4. The lubricant stirrer consists of a long plate 21, a
short plate 22 welded together by a hollow cross tube 23, the hollow cross tube
(23) providing a guidance for the metal wire, wherein the smaller plates 18
welded on the long plate (21) provides the necessary churning during rotation of
the lubricant stirrer (5), and wherein the lubricant stirrer is fixed on a rotating
shaft 3 by bolts 19 with corresponding seals 33 are provided between the soap
box and the rotating shaft to prevent contact of the lubricant with the outer
surface of the rotating shaft.
The die holder device 1 consists of a die casing arrangement and a rotating
arrangement. The rotating arrangement consists of the rotating shaft 3, a motor
with gear box 25, a gear motor mounting plate 2, and sprockets (35,36)
connected by means of chain 34. A covering 6 has been provided to cover the
chain. The rotating arrangement can be clearly understood from Figure 2 and
Figure 3. The sprocket 36 is connected to the rotating shaft (3) by means of
bolts 46. A ball bearing 30 is kept between the rotating shaft 3 and the die
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casing 1. The ball bearing (30) is maintained in the position by means of an
external circlip 24. The die casing 45 is kept in appropriate position by means of
a protrusion provided on the rotating shaft 3, as shown in Figure 3. Die nut 4
made of a lighter metal like brass and it consists of external threads. It is fixed
inside the rotating shaft containing internal threads. Cooling water at desired
flow rate is continuously fed to the die casing through a port 28 and drained
through a drain pipe 13 and drain exit27. The water is in direct contact with the
die casing which ensures excellent heat removal. Suitable water seals 44 and oil
seals 31 are provided to prevent leakage of water.
The motor mounting plate 2 is fixed to the die casing 1 by means of flat bolts 17.
Taper roller bearing 7 is provided between the rotating shaft, the mounting plate
and the die casing. Oil seals 32 are provided to prevent water from entering the
taper roller bearing. O rings 16 are provided to prevent dust from damaging the
bearings. Three different position adjustments are provided in the die holder box
assembly. Once the die holder assembly is fitted in a pafticular wire drawing
machine, there is a necessity to align the die casing along the wire drawing
direction. The finer movement in the UP and DOWN directions is achieved using
a hexagonal bolt 43. The adjustment in the horizontal plane (LEFT and RIGHT
movement) is achieved through a plate 12 using hexagonal bolt 14 and nut 47.
Plain bearing 37 is provided to ensure the smooth movement of the bolt 14 in
any direction. Another common issue that is encountered is in fitting of the die
holder device of one wire drawing machine in another wire drawing machine. For
that, the die box mounting plate 9 is fixed to the soap box 1 through a set of
allen bolts and washer 41. The mounting plate is connected to a shaft 11 using a
grub screw 40 as shown in Figure 2. The height of the die box system could be
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adjusted by adding or removing necessary spacers and tightening the bolt 38.
The die casing 45 is inserted into the die holder 1 from the top. Suitable profile
as shown in Figure 3 has been provided on the rotating shaft 3 to hold the die
casing. This method of inserting the die casing not only reduces the time for
inserting new dies, but also ensures excellent heat removal due to the direct
contact of cooling water with the die casing. Figure 5 shows the various positions
while inserting the die casing.
WE CLAIM
1. An improved die holder system with a single motor to concurrently
operate a rotating die holder device and a Iubricant stirrer device to
enhance die life in machines drawing metal wires, the system comprising
a die holder device releasably attached to a soap lubricant device, the
soap lubricant device having at least one chamber containing soap
lubricant, and a lubricant stirrer, the die holder device having a die casing
to accommodate a die and a motorized rotating means, wherein the
lubricant stirrer consists of a long plate 21, a shott plate 22 welded
together by a hollow cross tube 23, the hollow cross tube (23) providing a
guidance for the metal wire, wherein the smaller plates 18 welded on the
long plate (21) provides the necessary churning during rotation of the
lubricant stirrer (5), and wherein the lubricant stirrer is fixed on a rotating
shaft 3 by bolts 19 with corresponding seals 33 are provided between the
soap box and the rotating shaft to prevent contact of the lubricant with
the outer suface of the rotating shaft.
2. The system as claimed in claim 1, wherein the die holder device comprises
a die casing arrangement and an electro-mechanical rotating
arrangement.
3. The system as claimed in claim t or 2 wherein the die casing is insefted
into the die holder from the upper direction, and wherein a rotating shaft
of said rotating arrangement holding the die casing.