JPH0235724Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a yarn suction device that uses a thread hook or the like when winding synthetic fibers or the like.

<Prior art and its problems> Conventionally used yarn suction devices have a suction port that is a simple flat surface, or has multiple suction ports perpendicular to the yarn running direction to reduce the contact area with the yarn. There are some devices that have grooves, but the suctioned yarn comes in contact with the suction port, and as a result, the tension loss at the suction port is large due to friction between the yarn and the surface of the suction port, and the actual suction tension is reduced. There was a problem that the yarn was easily broken during threading. With recent technological developments, the winding speed of synthetic fibers has continued to increase, with winding speeds exceeding 3,000 m/min now common, and speeds exceeding 5,000 m/min at the development stage.

As speeds increase, the problem of the decrease in suction tension as described above and the problem of uncertainty in cutting and suctioning yarns running at high speeds have emerged as issues that need to be solved immediately.

Against this background, the yarn suction device itself has undergone many improvements in terms of the shape of the differential user and the nozzle type that generates the driving force for yarn suction. The ejection speed reaches the speed of sound, and there is a limit to increasing the size of the nozzle part when taking into account workability such as threading, so it is necessary to effectively use the suction driving force of the yarn generated in the nozzle part to the traveling yarn. A method is awaited. On the other hand, when yarn is cut and suctioned, it is important to improve yarn suction power and at the same time, to ensure stable running of the yarn at the suction port, so-called yarn gripping ability.

<Purpose and structure> The present invention was developed to solve such problems.It has good thread gripping characteristics, improves the reliability of thread cutting suction, and also improves the suction when suctioning threads such as threading. The purpose of this is to reduce the tension loss at the yarn contact portion at the tip of the device.

That is, the present invention provides a device that suctions yarn from a suction tube by ejecting compressible fluid, in which the yarn suction port of the suction tube has a plurality of grooves or grooves orthogonal to the yarn running direction. It has a protruding strip and a groove orthogonal to the groove or protruding strip, the depth of which is larger than the unevenness of the groove or protruding strip, and the surface roughness of the thread contacting part is 0.3 microns or more in terms of center line average roughness. It is characterized by:

<Example> The present invention will be explained below based on the drawings. Fig. 1 is a side view including a partial cross section showing an embodiment of the present invention, Fig. 2 is an enlarged front view of the suction port in Fig. 1, and Figs. 3 and 4 are A-A in Fig. 2, respectively. It is an arrow direction view of a line and a BB line cross section. In the figure, reference numeral 1 denotes the main body of the suction device. Working pressure air, which is compressed fluid, is introduced into the main body 1 through a supply pipe 2, and the compressed air is ejected from an unillustrated ejection nozzle provided in the main body 1 to generate a diffuser. By passing the suction tube 4
It is designed to generate a suction flow. The yarn passes through the suction tube 4 while contacting the peripheral wall of the suction port 3 located at the tip of the suction tube 4 and reaches the discharge tube 5, where it is sent out together with the expanded high-speed air. The suction port 3 consists of a mouth 6 fixed to the tip of the suction tube 4, and a plurality of circumferential grooves 7 are formed on the yarn contacting surface of the inner and outer peripheral surface of the tip so as to be orthogonal to the yarn running direction. The thread is engraved so that when the thread passes through the suction port 3, it mainly comes into contact with the crest 8 thereof.

In the present invention, it is necessary to form a plurality of grooves 7 or peaks 8. For example, when there is only one peak, there is a strong tendency for the yarn to contact only this part intensively. Conversely, the tension loss increases, making it difficult to perform good suction and threading. The number of grooves should be determined depending on the angle at which the direction of the thread running on the mouse 6 is changed, and is preferably one every 15 to 45 degrees.
It is also preferable that the grooves 7 be provided at approximately the same intervals as the tip of the mouth 6 to the suction tube 4 where the angle changes little.

The ratio of the grooves 7 and the peaks 8 of the suction port 3 depends on the yarn composition,
Since the value varies somewhat depending on the thickness, suction speed, etc., the optimum value may be determined as appropriate for each yarn.

On the other hand, when cutting a running yarn and suctioning it, it is necessary to reliably guide the yarn to the suction port and improve thread gripping ability, and the cut yarn end must be quickly removed from the suction port.
It needs to be guided through a suction tube to the nozzle and diffuser section inside the main body. For this reason, in the present invention, a slit 9, which is deeper than the groove 7, is provided in a straight line at the tip of the suction port 3 so as to be perpendicular to the annular groove 7 or the crest 8. In this case, the required tension when cutting the thread is usually smaller than the tension when threading, and it is not necessarily necessary to provide a groove in the bottom 10 of the slit 9 to reduce the contact length. It goes without saying that grooves may be provided as necessary.

Furthermore, in this invention, it is necessary that the surface roughness (center line average roughness Ra, according to JISB0601) of the thread contact area be 0.3 microns or more;
If it is smaller than 0.3 microns, the coefficient of dynamic friction increases rapidly, making it impossible to effectively utilize the reduction in tension loss by reducing the contact length.
When the surface roughness of the yarn contact area is 0.3 microns or more, the absolute value of the coefficient of dynamic friction does not change significantly, and the suction tension of the yarn is stabilized, and the surface roughness can be extremely controlled during the production of Mouse 6. It is easy to use and is particularly preferred industrially. On the other hand, the upper limit of the surface roughness is hardly regulated from the viewpoint of the coefficient of dynamic friction, but the upper limit of the surface roughness is The height (according to JIS B0601) is preferably 50 microns or less.

Function In such a device, the yarn Y drawn into the main body 1 is formed with a plurality of peaks 8 of protrusions formed by grooves 7 in the circumferential direction at the yarn contact portion of the suction port 3. Therefore, this contact length is small and the friction is also small, reducing the tension loss. However, the coefficient of dynamic friction between the yarn and the yarn contact area varies greatly depending on the center line average roughness of the yarn contact area, and if the surface roughness is selected incorrectly, the tension loss will decrease due to the decrease in the contact length mentioned above. cannot be used effectively.

However, as mentioned above, the device of the present invention has a small dynamic friction coefficient and a surface roughness that does not change, so even high-speed yarn can be taken up stably and easily, and there are fewer mistakes in threading operations. stomach.

In this way, the grooves 7 reduce the contact length of the yarn and the coefficient of dynamic friction is small and the surface quality is almost constant.
By applying this, a high suction tension level can be ensured during high-speed yarn suction and threading, and damage to the yarn and breakage will not occur. Naturally, this effect increases as the contact angle with the yarn increases.

Further, when cutting and suctioning the running thread, the thread Y is operated so as to pass through the slit 9. Here, the yarn Y is an annular groove 7 provided in the suction port 3.
Since the thread is guided through the slit 9 which is cut deeper, the thread gripping property is improved, and the thread stably runs approximately at the center of the suction port 3. In this case, the yarn cut at the point where it exits the suction port 3, including its yarn ends, is taken off by the air flow flowing from the suction port 3 toward the nozzle. At this time, the yarn Ya comes into contact with the bottom 10 of the slit 9, and tension loss occurs when running on the bottom 10, and the yarn Yb before entering the suction port 3
If the tension of the yarn Yc decreases, or if the tension of the yarn Yb is to be maintained at a constant level, it becomes necessary to increase the tension of the yarn Yc.
The thread speed becomes low, leading to thread trimming failure.

However, in the present invention, the bottom part 10 has a surface roughness of 0.3 microns or more as described above, which reduces tension loss due to friction, improves yarn gripping ability, and improves the reliability of yarn cutting and suction. Great improvements are planned, and the workability is also greatly improved without damaging the yarn before cutting.

The mouth 6 is usually chamfered and subjected to known surface treatments such as hard chrome plating or ceramic coating to prevent abrasion, but the mouse itself may be made of a wear-resistant material.

<Effects of the invention> As explained above, according to the present invention, it is possible to generate high suction force, which greatly reduces failures due to insufficient suction tension or yarn breakage when threading high-speed yarn. In addition, the thread cutting operation becomes more reliable, and productivity and workability are significantly improved.

[Brief explanation of drawings]

Fig. 1 is a side view showing a partial cross section showing an embodiment of the present invention, Fig. 2 is an enlarged front view of the suction port shown in Fig. 1, and Figs. 3 and 4 are respectively shown in Fig. 2. A-A
It is a cross-sectional view and a BB cross-sectional view. 1...Body, 3...Suction port, 4...Suction tube, 6
...mouse, 7...groove, 8...mountain, 9...slit.

Claims (1)

[Scope of utility model registration request] In a device that suctions yarn from a suction tube by ejecting compressible fluid, the yarn suction port of the suction tube has a plurality of grooves or protrusions perpendicular to the yarn running direction, and the grooves or a groove that is perpendicular to the protruding line and whose depth is larger than the groove or the unevenness of the protruding line, and the surface roughness of the yarn contacting part is the center line average roughness.
A yarn suction device characterized by having a yarn diameter of 0.3 microns or more.