JPS6034663A - Method for detecting pile yarn breakage in tufted machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to a tufting technique in which several hundreds of pile yarns are simultaneously tufted onto a base fabric, and when one pile yarn is broken during tufting and cannot be tufted. However, this is immediately detected and the drive motor of the tufted machine is stopped.

If you find a stitch row in the pile that does not tuft after tufting, repair it by tufting it with No-Tuff #8 (equivalent to a hook-druck machine) using a hand-held touch-knot machine that drives the mending machine one dollar at a time. . However, mending machines are meant to be hand held and tufted along rows of stitches that are not tufted.
Since repairs are made while moving, the stitch spacing varies,
The repair marks are visible as a difference in stitch density, and therefore we strive to detect pile yarn breaks early and shorten the repair distance as much as possible.

By the way, the base fabric from which the pile yarn is tufted has a coarse weave and is thin, and when light is shined on the tuft material from the back side, the light passes through the areas that are not tufted (stee and nochi rows) and appears bright. Thread cut flaws can be detected by

Focusing on this point, the pile yarn cut detection device is configured to use a photoelectric element to catch the transmitted light leaking at the yarn cut location, and to stop the drive motor of the tufted machine based on a change in the current passing through the photoelectric element. To do this, it is necessary to prepare a large number of photoelectric elements according to the number of stitch rows, that is, the number of pile threads, and arrange them for each stitch row, but the gap between the stitch rows is 2.54 cm. Hit 8~
The stitching is highly dense with 20 stitches (that is, 1/8 to 1/20 inch tuft gauge), and the fact that one photoelectric element is arranged in each of hundreds of stitch rows is a problem in terms of space. It is also considered impossible in terms of cost.

Therefore, as shown in FIG. 1, the conventional thread breakage detection device has a supporting frame 17 carry one photoelectric element 16 for every several stitch rows, and this supporting frame is moved in the width direction of the tufting machine.
In other words, it was configured to make reciprocating movements in the lateral direction, and to detect whether or not threads were trimmed in several rows of stitches using the photoelectric elements.

However, according to the conventional bail thread break detection device, the device operates when the stitch row is moving in the length direction during tufting, and the photoelectric element 16 supported on the support frame 17 is moved left and right by a distance l11tS. The stitch row moves by a distance MC in accordance with the tufting speed, and as a result, in each stitch row, the photoelectric element 16 reciprocates left and right and the thread is trimmed before returning to its original position (stitch row). Even if it occurs, it is not discovered, and therefore, a thread cut flaw with a length corresponding to at least the distance C is created.

In order to minimize this undetected thread cut flaw,
It is possible to increase the number of photoelectric elements and place them away from the tufted fabric, but the sensitivity of the photoelectric elements decreases in inverse proportion to the square of the distance from the tufted fabric. As you move away from the thread, the shadows of the looper bar, tufted machine frame, etc. will also enter the photoelectric element, making the shadow of the thread cutting area unclear.Alternatively, the individual detection (electrical) circuits may need to be adjusted depending on the variation in the quality of the photoelectric element. This may cause inconveniences such as having to do so.

The present invention solves this problem by convergently mapping the tuft front lines formed along the plurality of needles of the tufted machine onto the light receiving surface through a light receiving lens, and A photoelectric element is installed on a light-receiving surface along the front line, and thread breaks in the pile yarn are detected by changes in the amount of light received entering the photoelectric element through the light-receiving lens. Let us explain this in more detail with reference to FIG.

First, in Fig. 2, 1 is a needle bar, on the lower side of which a number of needles 2 are implanted, and a bushing rod 3.
The pile yarn 4 threaded through the tip of the needle 2 is tufted onto the base fabric 5 by the vertical reciprocating motion of the needle. A louver bar 6 is equipped with a number of loopers 7 corresponding to the number of needles 2, and receives pile loops from the needles 2 to form piles 8 on the base fabric 5.

91, 92, 93, . . . are multiple backstitch rows created on the base fabric 5, and the pile 8 is formed on the back side thereof. 1O is a light bulb that illuminates the fabric part 11 from the lower pile surface side.

At the upper front side of the fabric front in the tufting direction, there is a photographing device with a light-receiving lens 12 facing the fabric front, and its light-receiving surface 13
Orimae 11 bank stitch 91, 92, 93...
A horizontal row of bank stitches are projected in a straight line along the needle row, and on the light receiving surface 13, a tuft consisting of a horizontal row of bank stitches 91', 92', 93', etc. A linear photoelectric element 15 is installed along the woven line 14. Therefore, the photoelectric element 15 has a light receiving surface 1
The light of the shadow of the portion other than the tufted front portion 14 mapped to 3 does not enter. Photographing devices having photoelectric elements arranged in a straight line on the light-receiving surface are commercially available under the names of -dimensional CCD cameras and image sensors, and these can be used.

However, when pile thread breakage occurs, light leakage from the backstitch rows where the pile is not tufted and there are gaps appears on the photoelectric element 15 in the form of dots (91', 92', 93', etc.).
) and is mapped, and the resistance value of the photoelectric element 15 partially changes at the incident portion, thereby sending a split tube signal to the drive unit of the tufting machine to stop tufting.

A pile yarn cut detection device converges and maps the horizontal row of tufted fabric front sections formed along the plurality of needles of the tufting machine onto the light receiving surface through a light receiving lens, and the mapped horizontal row of tufted fabric front sections. As long as the photoelectric element is installed on the light receiving surface in a straight line along the length direction and is configured to sense the change in the amount of received light entering the photoelectric element through the light receiving lens, the tufted machine that maps the image onto the photoelectric element The location may be a horizontal row consisting of the tips of a plurality of needles through which the pile yarn is threaded. However, in this case, since the needle moves up and down for each stitch, the change in the photoelectric element is detected instantaneously at a fixed position selected from among the needle's highest position, lowest position, etc. This is done by installing a pulse generation circuit in the signal receiving section, and in order to clarify the shadow of the pile yarn passing through the needle tip, the pile yarn is irradiated with light.
It is preferable that the reflected light is convergently mapped onto the light receiving surface.

When trying to map more stitch rows onto the light-receiving surface, as shown in FIG. ) 21, 22, 23... Optical fiber (photoconductive fiber) 31, 32, 33
... Point the tip of (3, 3', 3''...),
The other end of Obtic fiber 41, 42, 43...
(4, 4°, 4''...) are arranged in a straight line and are then mapped onto an optical element formed in a straight line. The invention can be practiced.

Therefore, as is clear, the feature of the present invention is that, whereas in the past, the light leakage shadow of one stitch row was reflected on a single photoelectric element, in the present invention, the shadow of multiple stitch rows is reflected on one stitch row using a light-receiving lens. A point converged on the photoelectric element, a point captured by the entire photoelectric element with multiple stitch rows in a straight line without including other parts, and a point captured by the entire photoelectric element with multiple stitch rows in a straight line, excluding other parts. It is located at a point that is formed in a straight line so that it can be captured.

Since the thread breakage detection device according to the present invention is configured as described above, even if a thread breakage occurs in any one of the plurality of stitch rows to be mapped, it can be immediately detected, and the thread breakage caused by thread breakage can be detected immediately. Multiple tC circuits are installed along the length of the photoelectric element to detect local electrical changes in the linear photoelectric element for each part of the photoelectric element, which allows thread breakage to occur in which stitch row. It becomes possible to detect even the surface. Therefore, even if thread breakage occurs, the flaw is limited to a very short area, and thread breakage measures such as unreplenishment and splicing of threads in the stitch row where thread breakage occurs can be quickly carried out. It becomes possible to efficiently produce tufted fabric without thread cut flaws.

[Brief Description of the Drawings] Fig. 1 is a partially transparent perspective view of a conventional bail thread breakage detection device;
2 and 3 are perspective views of a bail thread breakage detection device according to an embodiment of the present invention.

Claims (1)

[Claims] A horizontal row of tufted fabric front sections configured along multiple needles of the tufted machine is convergently mapped onto the light receiving surface through a light receiving lens, and the mapped horizontal row of tufted fabric front sections are convergently mapped along the length direction of the horizontal row of tufted fabric front sections. A photoelectric element is installed on the light-receiving surface, and a change in the amount of light received by the photoelectric element that enters from the tufted fabric front part in a horizontal row through the light-receiving lens is detected as an electrical change in the photoelectric element, thereby detecting thread breakage in the pile yarn. Features: Pile thread breakage detection method in tufted machines.