JPS5894884A - Detection of stitch detachment of fabric - 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 method for detecting unstitched fabrics that can accurately and quickly detect the occurrence of unstitched errors in the sewing process of various types of fabrics using a sewing machine.

Although there have been significant advances in technology to automate the sewing process, such as the line closer that sews the panty part of Ml-j pantyhose, it has not been possible to completely prevent so-called unsewn errors in the sewing process, and sewing manufacturers has become a fatal flaw. For this reason, it has conventionally taken a great deal of manpower and time to test for its presence65, and there is a strong desire for a means to easily detect this.

The present invention has been provided for the purpose of solving these problems, and its feature is that the part of the fabric to be sewn, which is located immediately in front of the sewing machine needle of the sewing machine, is facing away from the sewing machine. The amount of transmitted light is measured by placing the light emitting element between the light emitting element and the light receiving element, and the average value is determined. The point is to detect. That is, when two pieces of fabric are sewn one on top of the other, either the upper or lower fabric may become uneven due to wrinkles, scratches, or curling, and if this is sewn as is, the sewing will be defective.

Therefore, the present invention detects the presence or absence of such irregularities as the amount of transmitted light, and prevents the sewing from coming off, or separately excludes the sewn product as a defective product, thereby making it possible to omit the inspection process. be.

° The present invention will now be described in detail with reference to the illustrated embodiments.
FIG. 1 schematically shows a line closer for automatically sewing the panty portion of μ pantyhose. In Figure 1, (
1) is a circumferential orbit, and (2) C is a clamper that moves along this circumferential orbit (1). (3) a sewing machine, (4) a sewing machine needle, and a light emitting element (5
) and a light-receiving element (6) that are vertically opposed to each other. (7) This is an air suction pipe that suctions and removes splattered non-defective products.

When sewing pantyhose, as shown in Figure 11!2, make cuts Q2Q3 by a predetermined distance from the upper edge rubber part αOtU+@ on two stockings (81t91), then cut both stockings (81Fe1 rubber part α0Q
After aligning both ends of l1, pull it so that the cut part becomes a straight line as shown in Figure CB), and sew both stockings (8091) along the sewing line α of the straight part to make the panty part (end). Then, the pantyhose shown in C) of the same figure are completed.

U5 when sewing pantyhose (2) like this
Set two stockings (81Fe2) on the clamper (2), stretch the cut part in a straight line, and sew the sewing line α4 of the panty part (2) using the sewing machine needle (4) of the sewing machine (3). However, when sewing, a light emitting element (5) and a light receiving element (6) provided in front of the sewing machine needle (4) detect whether the upper and lower fabrics are accurately aligned. In this case, if the upper and lower fabrics are aligned accurately, the amount of transmitted light will be as shown in Figure 8, and if the fabric is 1
If there are some irregularities, such as if there is only one sheet, the waveform will look like the 1m4 diagram. In this figure m8 and figure 144, although there are irregularities in the waveform, this is due to the fabric thickness, and the rubber part αGa
Since 1L is thick, the amount of transmitted light is reduced. Therefore, when making a difference in fabric thickness, even if a fixed detection threshold (A) is set as shown in Fig. 4, it is impossible to detect the unstitched part (b). It is possible. In addition(
c) U plain fabric, (d) t! The rubber part, (e) the U-panty part, and (f) show the crotch area, respectively.

Therefore, in the present invention, an inspection device as shown in FIG. In other words, if there is an actual measured value on the input terminal tube as shown in Figure 6, then it is averaged using an average value circuit consisting of a resistor and a capacitor (as shown in Figure 6) to obtain the average value. demand.

Then, input the actual measured value and the average value to the differential amplifier circuit, Inc., and find the deviation value between the two as shown in Figure 6 (Q).Meanwhile, use the threshold setting device @ to set the appropriate threshold value, [ll !6 figure (2)
] is set, and the deviation value is checked against this threshold value of the detection circuit, and this is used to detect whether or not there is a mistake in sewing the seam. If there is a mistake such as (g) or 8-layer fabric mistake (h), the detection circuit (
From c), the outputs shown in Fig. 6 (iv) are generated, and these can be detected accurately. In order to detect only the panty area, a gate signal ((■) in FIG. 6) is added to the detection circuit to limit the detection operation range. When a defective part is detected, the sewing machine (31f) will be stopped and repaired in conjunction with the signal from the sewing machine drive device.
Or, after sewing, the air suction pipe (7) was found to be defective.
) to separate the products from non-defective products.

Note that the present invention is not limited to pantyhose α0 and line closers, but can be applied to various sewn products and various sewing machines.For example, as shown in FIG. Light emitting elements (5
), attach the light receiving element (6) to the attachment (c) through the hole.
may be provided respectively. @U head.

In addition, "just before the sewing machine needle (4)" means just before the presser foot of the sewing machine (3) if there is a presser foot, or just before the sewing machine needle (4) when there is no presser foot, and in a broad sense, it means the place just before the presser foot of the sewing machine (3) when there is a presser foot. This refers to the state in which they are aligned and set in the sewing machine (3). In addition to attaching the light emitting element (5) and the light receiving element (6) to the attachment device shown in Figure 7, a separate bracket or the like is provided within the range that meets the above-mentioned conditions for the sewing machine (3). Also good.

As explained in detail in the above embodiments, in the present invention, a light emitting element and a light receiving element are used to measure the amount of transmitted light of the part of the fabric to be sewn, so that it is possible to prevent unstitched parts during the automated sewing process. Can be detected quickly.Since the difference between the actual tfC value and the average value is calculated and the unstitched part is detected based on this, even if it is used to detect differences in fabric thickness, it prevents piece movement due to changes in fabric thickness. It has a special effect on sewn products with different fabric thicknesses, and also improves the appearance of defects in stacked fabrics.
It has the advantage that it can be used in various situations, such as when one of two pieces of fabric turns over and becomes a single piece, or when the fabric is stacked eight times.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a line closer showing an embodiment of the present invention, Figure 2 is a diagram showing a method of sewing pantyhose, Figures 8 and 4 are waveform diagrams, and Figure 5 is a diagram showing the sewing method of pantyhose. FIG. 6 is a block diagram of a detection device showing one embodiment. FIG. 6 is a waveform diagram showing signals of each part thereof. FIG. 7 is a perspective view of main parts showing another embodiment. (3)...Sewing machine, (4)...Sewing machine needle, (5)...
...Light emitting element, (6)...Light receiving element, (to)...Pantyhose, concave...-Average value circuit, circle...
Differential amplifier circuit, ■...threshold setter, ■...detection circuit.

Claims (1)

[Claims] 1. Position the part of the fabric to be sewn immediately in front of the sewing machine needle between the light emitting element and the light receiving element that are placed opposite each other, and record the amount of transmitted light. A method for detecting unstitched parts of fabric, characterized by determining an average value and detecting unstitched parts by taking the difference between the actual III value and the average value.