Field of the Invention
[0001] The present invention relates to a yarn winder for continuously winding a filament
yarn such as synthetic fiber, which comprises a tension detector for monitoring yarn
tension during winding.
Background of the Invention
[0002] For winding control methods in the yarn winder for winding the filament yarn of synthetic
fiber that is melt-spun continuously from a spinning machine, to a bobbin while traversing
the filament yarn by a traverse device, two kinds of methods are mainly known, a yarn
speed control with yarn speed as control target, and a yarn tension control with yarn
tension as target.
[0003] The yarn speed control method had problems that when the traverse speed is changed
during winding, the yarn tension also changed, and it was difficult to control this
change in the yarn tension.
[0004] On the other hand, the yarn tension control method can form satisfying yarn packages,
without any bulge or saddle. Therefore, the yarn tension control method is considered
as an extremely effective technology in carrying out winding process that changes
the traverse speed during winding.
[0005] In the case the yarn tension control method is adopted, it is necessary to provide
the tension detector for detecting the tension of the yarn by contacting against such
yarn. However, having the tension detector to contact against the yarn that is running
at a high speed generally causes the yarn quality to deteriorate. Therefore, to reduce
bad influence on the yarn as much as possible, there is a method proposed conventionally
for the detection of the yarn tension. Such method is to provide the tension detector
directly below a traverse fulcrum, where the tension detector includes a contact member
that contacts minutely against both ends of the amplitude of the yarn that is traversed
like a swing of a pendulum (for example, Japanese Patent Publication No. 51-44668,
and Japanese Patent Publication No. 60-47985).
[0006] In the yarn winder adapting the yarn tension control method, the traverse fulcrum
guide and the tension detector can be attached to a fixed frame, and the traverse
device and a contact roller can be provided within an elevating unit. When forming
a yarn package by winding the yarn, which passes through the traverse fulcrum guide
and the tension detector and which is traversed by the traverse device, while contacting
the yarn against the contact roller, the elevating unit comprising the contact roller
can be elevated accompanying the increase in the winding diameter of the yarn package.
As a result, the contact pressure against the yarn package is maintained suitable.
However, accompanying the approach of the traverse device to a fixed traverse fulcrum
guide by the elevating unit that is elevating, the traverse angle of the yarn that
is traversed like a swing of a pendulum increases, and the yarn presses hard against
the contact member of the tension detector at both ends of the amplitude. As a result,
there is a problem in that an accurate tension value cannot be obtained.
Summary of the Invention
[0007] The object of the present invention is to provide a means for obtaining accurate
tension value, especially in a yarn winder that adopts the above-mentioned tension
detecting method. According to a first aspect of the present invention, a yarn winder
comprises a bobbin holder that is set with at least a bobbin for winding at least
a yarn, a contact roller that rotates while contacting against at least a yarn package,
a traverse device that is provided to an upstream side of the contact roller and traverses
the yarn that is being fed, a traverse fulcrum guide that is to be a traverse fulcrum
of the yarn that is traversed in the upstream side of the traverse device, and a tension
detector that is located between the traverse device and the traverse fulcrum guide
and that detects a tension of the yarn by contacting against a contact element, the
yarn that is located at both ends of the traverse amplitude. In addition, during winding
process, each of the distance between the traverse fulcrum guide and the tension detector,
the distance between the tension detector and the traverse device, and the distance
between the traverse fulcrum guide and the traverse device, is set constant regardless
of a winding diameter of the yarn package. According to the present invention, since
each of the afore-mentioned distances are set constant respectively, by maintaining
the condition to be constant when the yarn that runs while traversing like a swing
of a pendulum is contacted against the tension detector at both ends of the amplitude
to measure the yarn tension, an accurate tension value can be obtained.
[0008] According to a second aspect of the present invention, the present invention is preferable
to be applied to the yarn winder in which a traverse fulcrum guide and a tension detector
are attached to an elevating unit that includes the traverse device and that elevates
accompanying an increase in a winding diameter of a yarn package.
[0009] According to a third aspect of the present invention, the present invention can be
applied to the yarn winder wherein the bobbin holder descends accompanying the increase
in the winding diameter of a yarn package, and a contact pressure of the yarn package
against the contact roller is maintained suitable.
Brief Description of the Drawings
[0010]
Figure 1 is a side view showing schematic configuration of a yarn winder according
to an embodiment of the present invention.
Figure 2 is a front view showing principal components of the yarn winder of Figure
1.
Figure 3 is a perspective view showing a traverse fulcrum guide and a tension detector
of the yarn winder of Figure 1.
Figure 4 is a side view showing the yarn winder of Figure 1, under a condition in
which threading work is started.
Figures 5A and 5B are side views showing principal components corresponding to one
bobbin of the yarn winder of Figure 1 during a regular yarn winding process. Figure
5A shows a state in which the diameter of a yarn package is small. Figure 5B shows
a state in which the diameter of the yarn package is large.
Figure 6 is a front view showing principal components of the yarn winder, according
to another embodiment of the present invention.
Detailed Description of the Preferred Embodiments
[0011] An embodiment of the present invention will be described where the present invention
is applied to a yarn winder that forms a yarn package by winding while traversing
by a traverse device, a filament yarn of synthetic fiber that is melt-spun continuously
from a spinning machine.
[0012] Figure 1 is a side view showing a schematic configuration of a yarn winder M according
to an embodiment of the present invention. A plurality of bobbins B are set on one
bobbin holder H so that a plurality of yarn packages P can be formed at the same time.
In the drawing, four bobbins B are set on the bobbin holder H, however, the number
of bobbins set on the bobbin holder H can be six, eight, twelve, etc.. A machine body
K of the yarn winder M is provided with the bobbin holder H for holding a plurality
of bobbins B, and an elevating unit U including a traverse device T and a contact
roller C. The elevating unit U can elevate and descend in relation to the machine
body K. The yarn winder M is set such that accompanying the increase in the winding
diameter of the package P that is formed by the yarn being wound on the bobbin B,
the contact roller C elevates to maintain the contact pressure suitable.
[0013] The contact roller C is cylinder shaped, arranged in parallel to the bobbin holder
H, and is supported rotatable to a casing of the elevating unit U. The bobbin holder
H is cylinder shaped, supported in a cantilever to the machine body K, and is made
rotatable and driven by a motor (not shown in the drawings). Generally, in the yarn
winder M, two bobbin holders H are provided in 180 degrees interval on a turret plate
that is attached rotatable to the machine body K, and one of the bobbin holders H
is provided at a winding position, and the other bobbin holder H is provided at a
standby position. In the yarn winder M shown in Figure 1, the turret plate and the
bobbin holder H at the standby position are abbreviated.
[0014] As shown in Figure 2, the elevating unit U includes the traverse device T and the
contact roller C. A rotary blade traverse device, a cam traverse device, or the like
are adopted for the traverse device T. The traverse device T is provided with a traverse
guide 12 for guiding a yarn S in a traverse direction.
[0015] Above the elevating unit U, from the upstream side of the yarn path toward the downstream
side, a traverse fulcrum guide 1, and a tension detector 3 are provided in this order.
The traverse fulcrum guide 1 and the tension detector 3 are attached to a support
member 9 that is joined to a casing of the elevating unit U. As a result, the distance
between the traverse fulcrum guide 1 and the tension detector 3 during a winding process
(when the yarn S is wound around the bobbin B) is set to be constant regardless of
the winding diameter of the yarn package P. In other words, the traverse fulcrum guide
1, the tension detector 3 and the traverse device T are joined to the elevating unit
U so that to form one body, and as shown in Figure 5A that shows a case in which the
diameter of the yarn package P is small, and as shown in Figure 5B that shows a case
in which the diameter of the yarn package P is large, each of distances during winding
process, a distance L1 from the traverse fulcrum guide 1 to the tension detector 3,
a distance L2 from the tension detector 3 to the traverse device T, and a distance
L3 from the traverse fulcrum guide 1 to the traverse device T, are set to be constant
regardless of the winding diameter of the yarn package P.
[0016] The traverse fulcrum guide 1 that is provided to the upstream side of the yarn running
direction in relation to the traverse device T determines a standard position when
traversing the yarn S from side to side by the traverse device T. The standard position
at the winding process is set on approximately a bisector N of the traverse width
of the traverse device T. In addition, the traverse fulcrum guide 1 is guided by a
guide member 14 that is attached to the support member 9. The traverse fulcrum guide
1 is made transferable along the axis direction of the bobbin holder H toward a tip
end (free end) of the bobbin holder H, from the standard position shown in Figure
1 to an initial stage threading work position shown in Figure 4. The traverse fulcrum
guide 1 is, as shown in an enlarged view in Figure 3, formed with a ring-shaped guide
section 1a where the yarn S passes through, and a base 1c that supports the guide
section 1a. In addition, at an appropriate part of the guide section 1a, a notch 1b
is formed so that the yarn S can be inserted to the ring section 1a easily.
[0017] As shown in Figure 1, the tension detector 3 is provided between the traverse fulcrum
guide 1 and the traverse device T, and detects the tension of the yarn S that passes
through the traverse fulcrum guide 1 and that is traversed by the traverse device
T. For connecting cable for transmitting tension detecting signal to controllers provided
appropriately, the tension detector 3 is fixed on the support member 9, and is provided
on approximately the bisector N of the traverse width of each corresponding traverse
device T and directly below the standard position of the traverse fulcrum guide 1
in the winding process. As shown in Figure 3, the tension detector 3 includes a contact
element 4 that holds the yarn S at the tension detecting position, a shaft 5 that
is interlocked to the contact element 4, a pressure-sensitive sensor 6 that is attached
to both the left and the right sides of the shaft 5 in proximity to a base 7, and
the base 7 that supports the shaft 5. A storing section 4a for the yarn S is formed
on the contact element 4, by notching appropriate length from the center tip of the
contact element 4 in the axis direction of the shaft 5. In addition, insert guide
sections 4b that have slanting edges are provided to the left and right edges of the
contact element 4 so as to sandwich the storing section 4a. The storing section 4a
is a section for holding the yarn S at the tension detecting position. The insert
guide sections 4b guides the yarn S into the storing section 4a, which is the tension
detecting position, by a traverse movement of the yarn S at time of the initial stage
threading.
[0018] The tension detector 3 measures the tension of the yarn S during the winding process
in the following way.
[0019] As shown in Figure 3, when the yarn S, which passes through the traverse fulcrum
guide 1, is inserted through the storing section 4a of the contact element 4 and the
winding is carried out, the yarn S is traversed from side to side by the traverse
device T, as shown with chained double-dashed line in Figure 3. As a result, since
the yarn S is pressurized against the left and right inner edges of the storing section
4a, the shaft 5 transforms so as to vibrate to the traverse direction via the contact
element 4. The pressure-sensitive sensor 6 that is attached to the shaft 5 detects
the size of a force applied to the shaft 5 when the yarn S contacts against the contact
element 4, and calculates the tension of the yarn S in accordance with the detected
size. The tension detecting method adopted in the present embodiment can minimize
the influence to be applied on the yarn S, because the time when the tension detector
3 and the yarn S are contacting against one another is extremely short, and the bent
of the yarn S during the contact with the tension detector 3 is extremely small.
[0020] Further, for a subtle detection of the tension, the contact element 4 and the shaft
5 of the tension detector 3 are preferable to be light weighted as much as possible.
In this regard, the left and right edges of tip of the contact element 4 are preferably
to be tapered off by the insert guide sections 4b that have slanting edges. In other
words, the insert guide sections 4b are also contributing to reducing the weight of
the contact element 4 by narrowing the width of the contact element 4 toward the tip
end.
[0021] For winding each of the yarns S to each of a plurality of bobbins B that are set
on one bobbin holder H at the same time, the yarn winder M of the present embodiment
is provided with the traverse fulcrum guide 1, the tension detector 3 and the traverse
device T for each bobbin B.
[0022] Accompanying the increase in the winding diameter of the yarn package P, the elevating
unit U elevates to maintain the contact pressure of the contact roller C against the
yarn package P to be suitable. Since the traverse device T, the traverse fulcrum guide
1 and the tension detector 3 elevate as one body with the elevating unit U that is
elevating, as shown in Figures 5A and 5B, each of the distance L1 from the traverse
fulcrum guide 1 to the tension detector 3, the distance L2 from the tension detector
3 to the traverse device T, and the distance L3 from the traverse fulcrum guide 1
to the traverse device T is also maintained at a constant value respectively. Accordingly,
when measuring the tension of the yarn S by pressurizing the contact element 4 of
the tension detector 3 against the yarn S at both ends of the amplitude of the yarn
S that is traversed like a swing of pendulum while running, an agle θ1 and an agle
θ2 are maintained at constant value. As a result, a precise tension value can be obtained.
Further, the angle θ1 is an algle between the traverse fulcrum guide 1 and the tension
detector 3 that the yarn S is slanting in relation to the bisector N or the traverse
width of the traverse device T. The angle θ2 is an angle between the tension detector
3 and the traverse device T that the yarn S is slanting in relation to the bisector
N.
[0023] Further, the present invention wherein each of the distance between the traverse
device T and the traverse fulcrum guide 1, between the traverse fulcrum guide 1 and
the tension detector 3, and between the traverse device T and the tension detector
3 are maintained constant during the winding process, can be applied to the yarn winder
M, which the elevating unit U is elevated along with the contact roller C accompanying
the increase in the winding diameter of the yarn package. In addition, as shown in
Figure 6, the present invention can be applied to a yarn winder, which maintains the
contact pressure of the yarn package P against the contact roller C to be suitable
by descending the bobbin holder H in the direction of an arrow D, accompanying the
increase in the winding diameter of the yarn package P.
[0024] According to the first aspect of the present invention, the condition of when detecting
the yarn tension by contacting the yarn that is traversed like a swing of a pendulum
against the tension detector at both ends of the amplitude of the yarn during the
winding process, is maintained constant, and an accurate tension value can be obtained
regardless of the winding diameter of the package. As a result, high quality yarn
packages, which the tension is controlled at a target value, can be obtained.
[0025] In the case the contact pressure of the contact roller against the yarn package is
maintained suitable by elevating the elevating unit, accompanying the increase in
the winding diameter of the yarn package, it is especially preferable to apply the
second aspect of the present invention. As a result, the relationship of each of the
distances, the distance between the traverse device and the traverse fulcrum guide,
the distance between the traverse fulcrum guide and the tension detector, and the
distance between the traverse device and the tension detector, can be maintained constant
easily during the winding process.
[0026] According to the third aspect of the present invention, even in the case the contact
pressure of the yarn package against the contact roller is maintained suitable by
descending the bobbin holder accompanying the progress in the winding of the yarn,
accurate tension value of the yarn can be obtained regardless of the winding diameter
of the yarn package. As a result, high quality yarn packages, which the yarn tension
is controlled at a targeted value, can be obtained.