JPH054449B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the formation of pipe yarns in spinning machines such as ring spinning machines and ring twisting machines. More specifically, the present invention relates to a method for efficiently changing the rotational speed of a spindle during the formation of a tube yarn, thereby increasing productivity and suppressing the occurrence of yarn breakage.

Prior Art Yarn spun from a ring spinning machine is wound onto a bobbin inserted into a spindle while being guided by a traveler that slides on the ring, and the ring moves up and down as the ring rail to which it is attached moves up and down. It is formed as a tube thread as it moves along the bobbin. The ring rail repeats a relatively short raising and lowering stroke for each chase, gradually moving the stroke upward to form a uniformly stacked and uniform pipe yarn of yarn layers.

In the early stage of yarn formation, that is, when the ring rail is at the bottom and the yarn is wound around the base of the bobbin, sufficient yarn layers are not stacked, so the effective winding diameter of the bobbin is small, and The traveler resistance increases and the thread tension increases. Conversely, at the final stage of yarn formation, that is, when the ring rail is above and the yarn is wound on the top of the bobbin, the distance between the front roller and the ring rail, that is, the stretch, becomes shorter, absorbing tension fluctuations. The margin is reduced and the tension increases as a result. In order to prevent the occurrence of yarn breakage due to the increase in spinning force, many spinning machines change the rotational speed of the spindle during the process of tube yarn formation, and the spinning machine changes the speed of the spindle during the process of tube yarn formation. At the end of the process, the spindle is operated at low speed to reduce the tension, while at the intermediate stage, the spindle is operated at high speed to compensate for the drop in production. An example of this is shown in FIG.

The speed of this spindle is controlled by the mechanism shown in Figure 3 in response to an instruction signal from an auto counter that measures the spinning length of yarn installed in the spinning machine. This is done by displacing the upper part to change the speed. That is, there is a pair of stepped pulleys 2 and 3 between the machine motor M ₁ and the machine drive shaft 1, and the drive belt 4 is connected to these pulleys.
is being strung up. A belt moving lever 5 is supported by a rotating shaft 6 so as to be able to engage with the belt 4, and by rotation of the lever 5, the belt 4 can be moved to the low speed side or the high speed side. LS _L in the diagram
is a limit switch that stops the lever drive motor _M2 after confirming that the belt 4 has moved to the low speed side, and LS _H is a limit switch that stops the motor _M2 after confirming that the belt 4 has moved to the high speed side.

When the base of the pipe yarn is formed and the time for high-speed switching is reached, switch AC1 of the auto counter is activated to conduct the control circuit 1 shown in _FIG. is rotated in a predetermined direction, and the lever 5 is moved to shift the belt 4 to the high speed side. As soon as the movement of the belt 4 is completed, the lever 5 switches the limit switch LS _H.
Since the circuit 1 is pressed, the circuit 1 is opened again and the motor _M2 is stopped. At this time, the limit switch LS _L is disengaged from the lever 5 and is in a closed state as shown by the dotted line. Next, when the end of the tube formation is reached and it is time to switch to low speed again, the auto counter switch AC2 is activated, cutting off circuit 1 and closing circuit 3, so that the current flows through this and motor M. _{Step 2} is reversed and moves the lever 5 to shift the belt 4 to the low speed side. As soon as the movement of the belt 4 is completed, the lever 5 switches the limit switch LS _L.
Press to open circuit 3, so motor _M2 will stop.

Problems to be Solved by the Invention As mentioned above, the conventional spindle speed change is performed by a signal based on the spun yarn length set in an auto counter, but in this case, there are the following drawbacks. It was hot.

The ring rail repeats the lifting and lowering stroke for each chase, but there are fluctuations in the spinning force even within this one stroke. That is, as shown in FIGS. 4A and 4B, the effective winding diameter of the thread Y becomes smaller at the upper end of the chase, and therefore, the force applied to the thread to rotate the traveler 31 along the ring 32 is reduced. The tension increases, while the effective winding diameter of the yarn increases at the lower end of the chaser, conversely requiring less tension on the yarn. Therefore, there is a high correlation between the spinning force and the lifting and lowering of the ring rail for each chase, as shown in FIG. 5, and the stroke can be divided into a high tension region and a low tension region with the center of the stroke as the border.

When switching from low speed to high speed by the aforementioned spindle speed change, the spinning force naturally increases in steps. When this period just coincides with the high tension region of the chase stroke, both increases are added together, resulting in a rapid increase in tension in the thread, causing frequent thread breakage.

On the other hand, if the change from high speed to low speed coincides with the low tension range of the chase stroke, the tension in the yarn will be abnormally relaxed, and there is a risk that ballooning will collapse and yarn breakage will occur. Once this switching period has passed, the traveling posture of the traveler becomes stable and a new familiarity with the ring occurs, so that a stable state is entered again, but problems are particularly likely to occur at the switching timing.

The present invention has been made in order to solve the problems associated with changing the spindle rotation speed in the prior art.

Means for Solving the Problems The object of the present invention described above is to move the ring rail up and down in a short stroke, and gradually move the stroke upward to form a pipe thread on a bobbin inserted into a spindle. A method for forming a pipe in a spinning machine in which the base and head of the pipe are formed under low-speed rotation of a spindle, while the intermediate part is formed under high-speed rotation of the spindle, and the method includes switching from low speed to high speed rotation of the spindle. This is achieved by a method for forming a pipe yarn in a spinning machine, which is characterized in that the ring rail is moved in a low tension region during the up-and-down stroke, and switching from high speed to low speed is performed in a high tension region.

Effect: In the method of the present invention, the spindle rotation speed is increased in the low tension region during the lifting stroke of the ring rail, so there is no sudden increase in yarn tension, and the spindle rotation speed is decreased in the high tension region. Because it is done,
There is no rapid attenuation of the thread tension, and there are no sudden fluctuations in the thread tension, respectively.

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

FIG. 1 shows an example of a ring rail lifting mechanism of a ring spinning machine to which the method of the present invention is applied.

The rotation transmitted from the drive shaft 11 to the camshaft 14 via the worm 12 and worm wheel 13 rotates the heart cam 15, thereby causing the lifting lever 16 to swing around its rotation axis 17. A ring rail (not shown) is raised and lowered by a lifting chain 18 that is engaged with the tip of the lever 16. The chain 18 is gradually hoisted up with each stroke by the hoisting pulley 19, thereby gradually increasing the lifting stroke of the ring rail.

A sprocket 20 is attached to the other end of the camshaft 14, and two dogs 22a, 22b are attached coaxially by a chain 21 that engages with the sprocket 20.
Rotate. The dogs 22a and 22b are mounted with a phase difference corresponding to the vicinity of the maximum stroke portion and the vicinity of the minimum stroke portion of the heart cam 15, and operate limit switches LS1 and LS2, respectively.

This ring rail lifting mechanism is the third
The method of the invention is carried out by the circuit shown in FIG. 6 in cooperation with the transmission mechanism shown in the figure.

In FIG. 6, after the base of the tube is formed,
When the time to switch to high speed is reached, contact AC1 of the auto counter is first turned on. Next, when the dog 22a turns on the limit switch LS1 corresponding to the minimum stroke period of the heart cam 15 in FIG. 1, that is, near the lowest end of the ascending and descending stroke of the ring rail, the circuit 1 of the relay CR1 becomes conductive and self-maintains. At the same time, lever drive motor _M2 circuit 3
conducts, moves the lever 5, and switches the belt 4 to the high speed side. In this case, the contact of CR1 of circuit 4 is open, so that only the current from circuit 3 flows to motor _M2 . A normally closed limit switch LS _H is provided at the end of the movement path of the lever 5.
When turned off by , the circuit of motor M ₂ is interrupted and motor M ₂ stops. That is, by the above operation, it is possible to switch from low speed to high speed in the low tension region near the lowest end of the chase.

Next, switching from high speed to low speed at the final stage of tube formation is started by turning on contact AC2 of the auto counter. Then, the dog 22
When b turns on limit switch LS2, circuit 2 of relay CR2 becomes conductive and self-maintains. This opens the normally closed contact CR2 of the circuit 3, and instead turns on the normally open contact CR2 of the circuit 5, causing the motor _M2 to rotate in the opposite direction. As a result, the lever 5 returns to its original position, switches the belt 4 to the low speed side, and also switches the limit switch LS _L.
Operate to open circuit 5 and stop motor _M2 .
That is, by the above operation, it becomes possible to switch from high speed to low speed in accordance with the high tension area near the top end of the chase.

In the case of switching in the embodiment described, the motor
_M2 starts at the lowest or highest end of the stroke in the chain, and the levers, belts, etc. operate sequentially with a slight time delay, so the shift is completed as shown by A or B in Figure 5. This coincides with the point when the ring rail has slightly passed the trough or peak of the stroke, that is, the time when the ring rail has entered the ascending stroke or the descending stroke. This is a favorable trend, because when switching from low speed to high speed, it is better to loosen the thread to relieve the tension, and conversely, when switching from high speed to low speed, it is better to let the thread pull to reduce the tension. This is because it is better to prevent the decline.

Although the above embodiment describes a two-stage transmission using a belt shift method, the same technical concept can be applied to multi-stage transmission, or to any transmission method such as a variable pitch sheave method, an inverter method, or a volume conversion method. .

Effects of the Invention As detailed above, in the present invention, the spindle speed change timing is set rationally by taking into account the fluctuations in the spinning force during the lifting and lowering strokes of each chase of the ring rail, so that tension fluctuations due to speed changes are minimized. This makes it possible to suppress the occurrence of thread breakage.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a ring rail lifting mechanism used to carry out the method of the present invention, Fig. 2 is an example of a spindle speed change program, Fig. 3 is a perspective view of the speed change mechanism, and Figs. 4A and 4B are respectively FIG. 5 is a graph showing the relationship between the lifting stroke of the ring rail and the spinning force, and FIGS. 6 and 7 are diagrams showing the winding posture of the yarn at the upper and lower ends, respectively. 1 is an example of a circuit diagram used for implementation. M ₁ … Machine base motor, M ₂ … Lever drive motor,
4...belt, 5...belt moving lever 15..., heart cam, 16...lifting lever, 18...lifting chain.

Claims (1)

[Scope of Claims] 1. When raising and lowering the ring rail in a short stroke and gradually moving the stroke upward to form a pipe thread on a bobbin fitted into a spindle, the base and head of the pipe thread are is a method of forming a pipe yarn in a spinning machine, in which the intermediate part is formed under low speed rotation of the spindle, while the intermediate part is formed under high speed rotation of the spindle,
A method for forming a pipe yarn in a spinning machine, characterized in that the spindle rotation is switched from low speed to high speed in a low tension region during the vertical stroke of the ring rail, and from high speed to low speed is performed in a high tension region. 2. The method according to claim 1, wherein the spindle rotation is switched immediately after the ring rail starts rising or falling from the lower end or upper end of the chase.