JPH07138839A - Apparatus for controlling weft tension of loom - Google Patents

Abstract

PURPOSE:To actively control the tension applied to a weft at the traversing position of a weft transporting member according to the kind and fineness of the weft for weaving and avoid the weft breakage and the loosening of the weft at the end of the loom. CONSTITUTION:Plural fixed guides 5a are placed with prescribed spacings at a proper position on a yarn guide of a weft transported from a weft-storing apparatus to a weft-transporting member. A moving guide 5b moving perpendicular to the moving direction of the yarn is placed between the adjacent fixed guides. The moving guide is connected to a transmission apparatus utilizing a cam 18 driven synchronous to the rotation of the main shaft of a loom. The contact resistance of the yarn between the moving guide and the fixed guide is controlled by braking the movement of the moving guide is braked according to the moving position of the weft-transporting member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rapier weaving machine for controlling the tension of a weft yarn which is drawn from a weft yarn supply source and passes through a weft yarn storage device to a weft yarn carrier.

[0002]

2. Description of the Related Art Generally, in a rapier loom, as shown in FIG. 6, a weft drawn from a weft supply source A passes through a storage device B and passes between control means C made of a pair of elastic bodies. It is gripped by the carrier E and carried in the warp shed. At this time, the weft braking means C composed of a pair of elastic bodies (leaf springs) absorbs the fluctuation of the unwinding tension of the weft when being pulled out from the weft storage device B, and is conveyed from the weft braking means to the weft transporter. A certain braking force is applied to the weft thread. For this reason, while the weft transport body E travels in the warp shed, a constant tension is constantly applied to the weft conveyed to the transport body by the braking means made of this elastic body. The weft tension increases in proportion to the running speed of the weft transport body.

However, in recent years, in the rapier loom, it is desired to increase the loom rotational speed to 500 rpm or more, and the weft tension becomes excessive as the traveling speed of the weft transporter increases,
Depending on the type and fineness of the weft to be woven, the problem of frequent weft breakage has emerged. In addition, when the weft yarn is woven using a stretchable yarn, the weft yarn between the weft transport body and the braking means made of an elastic body is conveyed in an extended state, and thus the weft yarn is warped. When the weft is released at the machine base after being conveyed into the opening, the weft that has been stretched contracts and the weft relaxes. Therefore, in order to solve these problems, the device for responding by changing the gripping pressure of the weft thread by the elastic body to change the braking force applied to the weft thread (for example, Japanese Patent Laid-Open No. 2-242947,
JP-A-63-105148, etc.) was proposed, but it was not always sufficient depending on the weaving conditions such as the type of weft and the fineness.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, even when the number of rotations of the loom is increased to 500 rpm or more, the running position of the weft carrier (when weft gripping is performed) is appropriately performed according to the kind and fineness of the weft to be woven. We provide a device that actively controls the weft tension during weft delivery, weft release, and weft transport in the middle of these processes, thereby avoiding weft breakage and weft slack at the machine edge. is there.

[0005]

[Means for Solving the Problems] With respect to a plurality of fixed guides, which are drawn out from a weft supply source and are conveyed to a weft conveying body via a storage device, at appropriate positions on a yarn path at predetermined intervals. A moving guide that moves in a direction perpendicular to the traveling direction of the yarn is provided between the adjacent fixed guides. Further, this moving guide is connected to a control means for driving in synchronization with the rotation of the main shaft of the loom. Then, the movement of the moving guide is controlled in accordance with the traveling position of the weft conveying body to control the contact resistance of the yarn traveling between the moving guide and the fixed guide.

[0006]

The yarn drawn from the weft supply source passes through the weft accumulating device, passes through the weft braking device including the fixed guide and the moving guide, and is conveyed in the warp opening by the weft conveying body to be weft-inserted. . At this time, depending on the traveling position of the weft transporter, the moving guide is appropriately moved in a direction perpendicular to the traveling direction of the yarn with respect to the fixed guide, to impart a contact resistance to the weft. That is, when the weft carrier holds the weft, when the weft is delivered at the center of the machine base, when the weft is released at the machine end, and during the time when the weft in the middle of these points is being carried. By appropriately selecting the braking force applied to the weft at each timing in accordance with the type and fineness of the weft, weft breakage and loosening of the weft at the machine base can be avoided.

[0007]

1 is a weft supply source, 2 is a yarn guide eye, 3 is a weft storage device, and 4 is a yarn guide. Eyes 5 are weft braking devices arranged on the yarn path between the weft storage device 3 and the weft transport body, and the devices are a plurality of fixed guides 5a (fixed to a machine frame (not shown)). In the figure, five branches are shown from one main part) and moving guides 5b (four pieces are shown in the figure) arranged between the fixed guides 5a. In particular, the moving guide 5 is arranged so as to be movable in a direction perpendicular to the traveling direction of the yarn Y. Reference numeral 6 denotes a means for braking the movement of the moving guide 5b. The main part of this braking means is a swing shaft 7 for supporting the moving guide 5b, and a main shaft of a loom serving as a drive source for swinging the swing shaft 7. The cam drive mechanism 14 is driven in synchronization with (not shown). That is, the support shaft 7 to which the moving guide 5b is attached
Is rotatably supported by a machine frame (not shown) and is fixed to a swing lever 8. The swing lever 8 is fixed by a pin 9 to a link lever 10 that moves in the horizontal direction. A spring 11 is attached to one end of the link lever 10 and a wire 13 is attached to the other end of the link lever 10 by a holder pin 12. One end of the wire 13 is attached to the link lever 10 by the holder pin 12, and the other end is fixed to the cam lever 15 by the holder pin 12. The cam lever 15 is swingably supported by a machine frame (not shown) by a shaft 16. 17 is the cam lever 15
A cam trochanter attached to one end of the plate cam, a plate cam 18 that engages with the cam rotator 17, and an auxiliary plate cam 19 attached to the side surface of the plate cam 18.

The shapes of the outer peripheral surfaces of the plate cam 18 and the auxiliary cam 19 are closely related to the moving distance of the moving guide 5b, and when the weft conveyer grips the weft and when the weft is delivered at the center of the machine base. At the time of further release of the weft yarn at the machine end, the movement guide 5b is moved in the direction perpendicular to the traveling direction of the yarn. On the other hand, at a position other than these points, the weft yarn is shaped so as to exert almost no braking force. None, further, particularly when the weft is released, the auxiliary plate cam 19 engages with the rotator 17 instead of the plate cam 18 to determine the moving distance of the moving guide 5b, and the braking force applied to the weft is finely adjusted in a stepless manner. It has a shape that can be changed. An example of these cams is shown in FIG. The auxiliary cam 19 is provided with an elongated hole portion 19a and is fixed to the side surface of the plate cam 18 by a bolt 19b.

A camshaft 20 is driven in synchronization with a main shaft (not shown) of the machine base. The plate cam 18 and the auxiliary cam 19 are attached to the camshaft. In addition, 21
Is a sensor for detecting the presence or absence of wefts, 22 is a finger of the multicolor weft selection device (only one is shown in the figure), and 23 is a weft carrier.

An example of the apparatus for carrying out the present invention is constructed as described above. Next, the operating state thereof will be described. In FIG. 1, the weft Y unwound from the weft supply source 1 is a guide eye. It is guided to the weft yarn storage device 3 via 2 and further to the weft yarn braking device 5 from the weft yarn storage device 3 via the yarn guide eye 4. In the weft braking device 5, the weft is bent between the fixed guide 5a and the moving guide 5b to provide a contact resistance. Next, the weft that has passed through the weft braking device 5 is passed through the weft sensor 21, the weft selection finger 22 and gripped by the weft carrier 23 to be inserted into the warp opening.

Now, the operating state of the moving guide 5b will be described. When the camshaft 20 driven by an appropriate transmission means is driven from a loom main shaft (not shown), the plate cam 18 and the auxiliary cam 19 are driven. Depending on the shape
The cam lever 15 swings left and right with the shaft 16 as a fulcrum via the cam roller 17. Now, when the cam lever 15 rotates clockwise about the shaft 16 as a fulcrum, the wire lever 13 is pulled rightward via the holder pin 12 at the tip of the cam lever 15, and the link lever 10 also moves rightward. Therefore, the swing lever 8 fixed to the link lever 10 by the pin 9 causes the support shaft 7 to rotate counterclockwise. When the support shaft 7 rotates counterclockwise, the moving guide 5b moves from the position shown by the dotted line to the position shown by the solid line with respect to the fixed guide 5a. As a result, the weft Y bends between these guides and the contact resistance increases, so that the weft tension increases. This moving guide 5
The moving distance of b is determined by the shapes of the outer peripheral surfaces of the plate cam 18 and the auxiliary cam 19. Also, in particular, the auxiliary cam 1
When the mounting position of the plate 9 with respect to the plate cam 18 is changed (moved to the left and right as shown by the arrow in the drawing), the braking force can be changed as shown by the curve indicated by the chain double-dashed line in C of FIG.

The tension applied to the weft by the fixed guide 5a and the moving guide 5b will now be described. In FIG. 3, the horizontal axis represents the rotation angle of the main shaft of the loom, and the vertical axis represents the rotation angle. Represents the traveling speed of the weft carrier and the magnitude of the braking force applied to the weft by the weft braking device. Curve A shows the change in running speed of the weft carrier,
On the other hand, the curve B shows changes in the braking force applied to the weft. Here, point a is the point where the weft carrier holds the weft, point b is the point where the weft insertion carrier transfers the weft to the receiving carrier at the center of the machine base, and point c is the machine end. Shows the point where the weft is released. As shown in the figure, the braking force applied to the weft varies depending on the traveling position of the weft transporter. That is, a constant braking force is applied to the above-mentioned points A, B, and C of the weft carrier, but is almost zero at other traveling points. Further, particularly at the point C, the braking force on the weft can be changed by adjusting the mounting position of the auxiliary cam 19.

In FIG. 4, the horizontal axis represents the rotation angle of the main shaft of the loom, while the vertical axis represents the weft thread tension. In the case of the present invention where the weft thread is the sixth cotton thread, the weft thread tension of the conventional example is shown. It is a comparison of changes. In the case of the present invention, the maximum value of the weft tension is considerably lower than that of the conventional example. In addition, the magnitude of the weft tension at the point C can be changed separately from the points at the points A and B. The magnitude of the weft tension is empirically optimally selected depending on the weaving conditions. On the other hand, in the case of the conventional example, this cannot be done.

[0014]

As described above, according to the present invention, the weft transporter holds the weft that is pulled out from the weft supply source and unwound through the weft storage device, and travels in the warp opening to enter the weft. Since the tension applied to the weft during one weft insertion cycle can be appropriately selected according to the type and fineness of the yarn, the number of rotations of the loom is 500, in comparison with the conventional case.
At a high speed of rpm or more, for example, even for a weft yarn having a weak yarn strength, the maximum tension applied to the weft yarn can be reduced, so that the yarn breakage can be avoided and, for example, a weft yarn having a large shrinkability can be obtained. In the meantime, when the weft carrier completes weft insertion and releases the weft, it is possible to appropriately select the degree to which the stretched weft contracts, so that the woven fabric surface becomes uniform in quality. Produce an effect.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of the vicinity of a weft insertion portion of a rapier loom including the device of the present invention.

FIG. 2 is an explanatory diagram showing an operating state of a weft braking device.

FIG. 3 is a graph showing changes in the running state of the carrier and the braking force applied to the weft during the weft insertion period of the loom 1.

FIG. 4 is a graph showing changes in tension applied to wefts of the present invention and a conventional case.

FIG. 5 is an enlarged explanatory view of a part of a main part of the device of the present invention.

FIG. 6 is an explanatory diagram corresponding to FIG. 1 in the case of the conventional example.

[Explanation of symbols]

 1 Weft supply source 3 Storage device 5 Braking device 5a Fixed guide 5b Moving guide 14 Cam drive mechanism (control device) 18 Plate cam 19 Auxiliary cam 23 Weft carrier Y yarn

Claims (1)

[Claims] 1. A plurality of fixed guides arranged at predetermined intervals at appropriate positions on the yarn path of the weft that is pulled out from the weft supply source and conveyed to a weft transporter via a storage device.
A moving guide that moves in a direction perpendicular to the traveling direction of the yarn is provided between adjacent fixed guides, and the moving guide is connected to a control unit that drives the weaving machine in synchronization with the rotation of the main shaft of the weaving machine. A weft tension control device for a loom, characterized in that it controls the movement of the moving guide in accordance with the position to control the contact resistance of the yarn running between the moving guide and the fixed guide.