JPH0129894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel draft device. More specifically, the present invention relates to a draft device suitable for high-speed spinning machines such as bundle spinning machines.

In recent years, spinning processes have become faster, and spinning speeds of 100 m/min or more to around 200 m/min have been practically achieved in binding spinning machines that use air false twisting nozzles to produce binding yarns. It's reached. At such high speeds, various obstacles occur in the draft device compared to the low speed spinning of only 20 m/min of conventional ring spinning machines. The biggest problem is a drastic increase in damage to aprons, and according to the inventors' experience, most aprons become unusable due to cutting or wear after about one month of continuous operation. . That is, in bundle spinning, apron maintenance is an essential task for continuing operations and maintaining the quality of spun yarn. However, as is well known, replacing the apron, especially attaching and removing the apron on the bottom side, is usually done in one step because the bottom roller is commonly provided from the gear end to the out end of the machine through all spindles of the spinning unit on one side of the machine. It is impossible to perform this work on each spinning unit individually, so it is necessary to stop the machine and perform this work on all the spindles of one spinning unit all at once, before the apron becomes too worn out. It was extremely wasteful both in terms of material and parts.

The present invention has been made in view of the drawbacks of the prior art, and involves removing the apron attached to the bottom roller, replacing it with a small-diameter roller, and removing the fibers being drafted between the roller and the apron on the top side. The purpose is to grip the bundle and control floating fibers. In other words, parts that are easily worn out, such as a rubber apron, are used only on the top side, where they can be easily replaced, and small diameter metal rollers are used on the bottom side, thereby extending their life semi-permanently. This is what I expected.

The present invention will be explained in more detail below based on the drawings.

In one embodiment of the present invention shown in FIG. 1, the fiber bundle F fed from the right side is fed to the back crawlers 1, 2;
middle rollers 3, 4; and front rollers 5, 6
While passing between each pair of fibers, the ribbon-like fiber bundle F' is gradually stretched thinner and sent out from the front rollers 5 and 6 as a ribbon-like fiber bundle F' having a predetermined thickness, and introduced into the air false twisting nozzle 11 as it is. It is spun into binding yarn Y. Usually, the first draft zone between the back rollers 1, 2 and middle rollers 3, 4 is about 5 to 7 times, and the second draft zone between the middle rollers 3, 4 and front rollers 5, 6 is about 20 times Since drafting is performed at a high magnification of ~35 times, control of floating fibers within the fiber bundle is important to achieve uniform drafting.

In this embodiment, the middle roller 3 on the top side
As in the past, an apron 7 made of a flexible material such as a rubber sheet is wrapped around the apron 7 so that it can be rotated under appropriate tension by a tensor 8. A small-diameter control roller 9 is pressed from the bottom side, and a rotatable guide plate 10 is installed behind it with an appropriate gap along the lower surface of the apron 7, thereby holding the fiber bundle F in between. I am doing what I do. The control roller 9 is connected to a drive source (not shown) by a suitable transmission means so as to be driven at the same surface speed as the middle roller 3 or at a slightly higher speed.

Since the upper surface of the control roller 9 is in biting contact with the lower surface of the apron 7, both of them apply soft pressure to the fiber bundle ribbon F' with a fairly wide curved surface along an arcuate surface, and the fiber bundle is pushed into the middle. After leaving the nip point between the rollers 3 and 4, the travel path is regulated by the guide plate 10, and the sheet is conveyed at a uniform speed with a slight tension to the soft contact surface between the control roller 9 and the apron 10. Then, it is reliably conveyed without floating to the nip point between the front rollers 5 and 6, which are set at a sufficiently short interval.

Here, the distance between the nip point of the middle rollers 3 and 4 and the axis of the control roller 9 is slightly shorter than the average fiber length L of the staples constituting the fiber bundle to be processed, and the distance between the nip point and the front roller 5, It is desirable that the distance to the nip point No. 6 be set slightly longer than the average fiber length L. Also, the smaller the diameter of the control roller 9, the closer it can be placed to the nip point of the front rollers 5 and 6, which allows for better control of floating fibers. 10～ using finishing steel as material
Approximately 12 mm is suitable. Furthermore, the mounting positions are front bottom roller 6 and middle bottom roller 4.
It is desirable that the upper surface of the controller 9 be set to be at the same position or slightly above a line connecting the upper surfaces. With this configuration, it is possible to reliably perform draft control on the fiber bundle F traveling at high speed, and the false twisting nozzle 11 acts on the fiber bundle F' that has exited the front rollers 5 and 6, resulting in uniform bundling. Spin yarn.

According to the present invention, even if the bottom apron is a consumable part and its replacement work is complicated, it is possible to achieve a draft control effect that is sufficiently comparable to the bottom apron. etc. can be drastically reduced.

[Brief explanation of drawings]

The drawing shows a schematic side view of an embodiment of the invention. 1, 2... Back crawler, 3, 4... Middle roller, 5, 6... Front roller, 7... Apron, 8... Tensa, 9... Control roller,
10... Guide plate, F, F'... Fiber bundle, Y
...Binding thread.

Claims (1)

[Scope of Claims] 1. In a drafting device in which pairs of top and bottom front rollers, middle rollers, and back rollers are sequentially arranged, an apron is wrapped around the middle roller on the top side, and a portion near the tip of the apron is wrapped around the middle roller on the top side. A fiber bundle drafting device consisting of a small-diameter control roller pressed against the bottom side of the fiber bundle. 2. The draft device according to claim 1, wherein the control roller can be driven at substantially the same speed as the surface speed of the middle roller or at a slightly higher speed. 3. Claim 1 or 2, wherein the control roller is made of chrome-plated steel.
Draft device as described in section.