JPH10170231A - Detecting device for skip stitch of seam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately detect the skip stitch of a seam. SOLUTION: The machine sewing seam part 3 of the end of a bag 1 is sewed with a machine sewing thread. The image of a seam part 4 is caught by a camera 6 as the bag 1 is carried on a carrying line 5. An image signal sent from the camera is processed by a detection signal creating means 8, and a detection signal corresponding to the seam 4 is taken out. The detection signal is processed by a width dimension detecting means 9 to detect the width dimension of the seam 4. The width dimension of the seam 4 and the width dimension of a normal seam 4 obtained by a normal width memory means 10 are mutually compared by a judging means 11 to judge the existence of a skip stitch. Since the width dimension of the seam 4 of a part having a skip stitch is different from the width dimension of the seam 4 of a part having no skip stitch, the existence of the skip stitch can be easily and accurately detected by the method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stitch skip detecting device used in a bag manufacturing process or a filling process of contents, and in particular, a stitch skip can be detected accurately with a simple device configuration. The present invention relates to a stitch skip detection device.

[0002]

2. Description of the Related Art Generally, in a bag manufacturing process, a perforated portion formed at a lower end opening of a bag body having a flat cylindrical shape is formed.
Sewing is performed with a sewing thread, and in the filling step of the contents, after filling the contents into the bag body whose lower end is sewn, a perforation formed at the upper end opening of the bag body is performed. The part is sewn with a sewing thread.

[0003] By the way, if there is a sewing defect in the stitches of these stitches, that is, skipped stitches, the stitches are carelessly taken at the time of filling the contents or carrying the bag filled with the contents. Therefore, in the bag manufacturing process or the filling process of the contents, it is necessary to inspect whether or not the seams are skipped one by one.

[0004] Conventionally, an operator inspects the bags after the manufacture or the bags filled with the contents one by one for the presence or absence of skipping by visual inspection. However, the work is not easy and there is an oversight. There is a problem.

In order to solve such a problem, in part,
There has been proposed a method of detecting stitch skips using an image processing technique.

[0006]

In the detection of stitch skipping by the above-mentioned image processing, stitching is grasped as an image to form a stitch pattern, and this pattern is compared with a regular stitch pattern. In general, a method of detecting the presence or absence of a frame is used. In this method, it is necessary to prepare two or more large-capacity frame memories and an arithmetic unit capable of processing image data at high speed is required. Therefore, there is a problem that the device configuration is large and complicated, and the cost is high.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an inexpensive stitch skip detecting device which can detect stitch skips with a simple structure and high accuracy. .

Another object of the present invention is to provide a stitch skip detecting device which can set the inspection start end and the inspection end with high accuracy for the seam of each bag and can improve the inspection accuracy. .

Another object of the present invention is to provide a stitch skip detecting device which can reliably sort a good product having no skip and a defective product having a skip.

Still another object of the present invention is to provide a stitch skip detecting device which can clearly distinguish non-defective products having no skip from defective products having skip, thereby facilitating work such as rework. To provide.

[0011]

By the way, as a result of repeated experiments on the seam by the present inventors and others, the width of the seam has been found to be different between the portion where the skip is generated and the portion where the skip is not generated. Found a difference. If the presence or absence of skips is detected based on the difference in the width of the stitches, it is expected that the skips of the stitches can be easily and accurately detected.

The present invention has been made based on such findings, and a conveying means for conveying a bag in which a perforated portion formed at an end of a bag body is sewn with a sewing thread in the longitudinal direction of the seam; And imaging means for continuously or intermittently capturing the seam portion as an image having a predetermined width in the transport direction; and detecting the generation of a detection signal corresponding to the seam based on the image signal captured by the imaging means. Signal generation means; width dimension detection means for detecting the width dimension of the stitch based on the detection signal from the detection signal generation means; normal width storage means for storing the width dimension of a regular stitch without skipping;
Determining means for comparing the width dimension of the stitch detected by the width dimension detecting means with the width dimension of the regular stitch from the regular width storage means to determine whether or not there is skipped stitches. Features. Then, the width of the stitch detected by the width detecting means is compared with the width of the regular stitch without stitching to determine the presence or absence of stitching. It is possible to detect stitch skips with high accuracy, and it is possible to manufacture at low cost.

The present invention further comprises an end detecting sensor for detecting a leading end and a trailing end of the bag body in the conveying direction, and a feed amount detecting sensor for detecting a conveying distance of the bag, respectively. After the sensor detects the leading end of the bag body in the carrying direction, it is activated when the feed amount detecting sensor detects an arbitrary set carrying distance, and after the end detecting sensor detects the trailing end of the bag body in the carrying direction, The apparatus is characterized in that it stops when the feed amount detection sensor detects an arbitrary set conveyance distance. As a result, it is possible to accurately set the inspection start end and the inspection end for the seam of each bag, and as a result, it is possible to improve the inspection accuracy.

The present invention is further characterized in that a distributing mechanism for distributing non-defective products and defective products based on an output signal from the judging means is provided downstream of the imaging means of the conveying means. This makes it possible to reliably sort good products without skips and defective products with skips,
Later work is easy.

The present invention is further characterized in that a mechanism is provided downstream of the image pickup means of the transport means for providing an identification mark to a defective product based on an output signal from the determination means. This makes it possible to clearly distinguish non-defective products having no skips from defective products having skips, which is convenient for work such as rework.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a stitch skip detecting device according to an embodiment of the present invention. In the drawing, reference numeral 1 denotes a perforated portion 3 formed at a lower end portion of a bag body 2 having a flat cylindrical shape. A seam 4 is formed in a perforated portion 3 of the bag 1 by sewing with a sewing thread. And this bag 1
Is transported by the transport line 5 in the longitudinal direction of the seam 4.

As shown in FIG. 1, a camera 6 as an image pickup means is installed on the transport line 5, and the camera 6 moves the seam 4 in a predetermined direction in the transport direction as shown in FIG. The image 7 is continuously captured as the width image 7. Then, the image signal captured by the camera 6 is sent to the detection signal generation means 8,
The detection signal generating means 8 generates a detection signal corresponding to the seam 4 based on the image signal from the camera 6. Specifically, the image signal is differentiated to make the edge of the seam 4 visible, and the differentiated signal is full-wave produced and then binarized (digitized) to generate a binary signal. A binary width signal is generated based on the binary signal. This will be described later in detail.

The detection signal thus obtained is shown in FIG.
As shown in (1), the width is detected by the width detecting means 9. The width detecting means 9 detects the width of the stitch 4 based on the input detection signal.

On the other hand, the width of the regular seam 4 without stitches is stored in advance in the regular width storage means 10, and the width of the regular seam 4 is detected by the width dimension detecting means 9. The width of the seam 4 is input to the judging means 11 together with the width, and the judging means 11 compares the widths. The presence or absence of skipping is determined based on the comparison result. Specifically, a certain allowable range is set corresponding to the width of the regular seam 4, and when the width of the seam 4 detected by the width detecting means 9 is out of the allowable range, a predetermined allowable range is set. It is determined that there is a jump. For example, if the width of the regular seam 4 is 2 mm, the allowable range is 1.5 to 2.
5 mm is set, and when it is out of this range, it is determined that there is skipping.

As a method of storing the width of the regular seam 4 in the normal width storage means 10, an operator actually measures the width of the seam 4 using a scale or the like, and inputs the measured value to the input means. In this embodiment, the bag 1 having the stitches 4 without skipping may be input.
Is transported by one bag on the transport line 5, and the width of the seam 4 in each image 7 is obtained over the entire length of the seam 4 by using the camera 6, the detection signal generation means 8, and the width dimension detection means 9. An average value of these is obtained by a calculation means (not shown), and the average value is stored in the normal width storage means 10 as the width dimension of the regular seam 4 without skipping.

FIG. 3 shows a specific example of the detection apparatus shown in FIG. 1. In the drawing, reference numeral 12 denotes a sewing machine mechanism installed on the upstream side of the transport line 5, and a downstream side of the sewing machine mechanism 12. A beam sensor 1 as an end detection sensor for detecting a front end and a rear end of the bag body 2 in the transport direction, respectively.
3. Camera 6, light 1 for illuminating the imaging range of camera 6
4, and a rotary encoder 15 as a feed amount detecting sensor for outputting a reference pulse are provided, and a distribution mechanism 16 for distributing non-defective products and non-defective products is disposed on the downstream transport line 5. Have been. And
The beam sensor 13, light 14, camera 6, rotary encoder 15 and distribution mechanism 16 are respectively connected to a controller 17 and controlled by a signal from the controller 17. As shown in FIG. 3, a monitor 18 for displaying a defect image, a signal processing display, a detection parameter display, and the like, and an operation key 19 for inputting inspection parameters and the like are connected to the controller 17, as shown in FIG.

The camera 6, beam sensor 13, light 14, rotary encoder 15, and distribution mechanism 16
Is mounted on an inspection table 20 installed in the middle of the transport line 5 as shown in FIGS.

That is, as shown in FIGS. 4 and 5, the inspection table 20 includes a wide belt 1
An upper feed belt 22 having two narrow bands is provided, and these two feed belts 21 and 22 are driven to rotate by a drive source (not shown) to convey the bag 1 from left to right in the figure. ing. These two feed belts 21 and 22
Is transmitted to the rotary encoder 15 so that the rotary encoder 15 is driven.

As shown in FIGS. 4 and 5, the inspection table 20 has lights 14 and
Air nozzles 23 are provided respectively for injecting air toward the camera 6 and the lens of the camera 6 to prevent dust from adhering. A beam sensor is provided above the upper feed belt 22 and slightly upstream of the camera 6. 13 are provided. The start and stop of the camera 6 are controlled based on a signal from the beam sensor 13.

That is, as shown in FIG. 6, the beam sensor 13 detects the leading end and the trailing end of the bag body 2 in the transport direction, respectively. After detecting the leading end of
Together with the bag 1 is activated when it is transported by a distance L _1, then the beam sensor 13 detects the conveying direction trailing end portion of the bag body 2 is stopped when the bag 1 is conveyed by the distance L ₂ It has become. And by this, the inspection range is limited to the range of dimensions L ₃ except for the both end portions of the perforated portion 3,
It is possible to completely prevent an error due to inspection up to the end of the perforation 3, that is, an erroneous operation in which it is determined that skipping occurs even though there is no skipping. The distances L ₁ and L ₂ are measured by counting the number of reference pulses from the rotary encoder 15 to the controller 17.
(See FIG. 3).

As shown in FIGS. 4 and 5, a distributing mechanism 16 having an oscillating flap 24 is disposed downstream of the feed belts 21 and 22. By driving the cylinder 25, the cylinder 25 swings up and down between a solid line position and a chain line position shown in FIG.

Next, the operation of the present embodiment will be described. The bag 1 in which the perforated portions 3 are sewn in the sewing machine mechanism 12 shown in FIG. 3 is transported by the transport line 5, and is eventually sent between the two feed belts 21 and 22 of the inspection table 20 installed in the transport line 5. .

Then, first, as shown in FIG.
The conveying direction leading end portion is detected by the beam sensor 13, together with the camera 6 is activated when after detection bag 1 is conveyed by the distance L _1, the beam sensor 13 detects the conveying direction trailing end portion of the bag body 2 after the camera 6 is stopped when the bag 1 is conveyed by the distance L _2. And this way, the range of dimensions L ₃ of the seam 4 is examined.

By the way, when the camera 6 is activated, as shown in FIG. 2, the camera 6 continuously captures the seam 4 as an image 7 having a predetermined width in the transport direction. Then, each captured image 7 is sequentially sent to the inspection signal generating means 8 shown in FIG. Inspection signal generation means 8 generates an inspection signal for each of the input image signals. Specifically, the processing shown in FIG. 7 is performed.

That is, the inspection signal generating means 8
, An image signal indicated by a is input. Then, the inspection signal generation means 8 first differentiates the image signal a to generate a differential signal b, and generates a differential signal c by full-wave rectifying the differential signal b. Thereafter, the differential signal c is binarized (digitized) to generate a binary signal d, and finally, a binary width signal e is generated based on the binary width signal d. Then, the binary width signal e is output to the width dimension detecting means 9 as an inspection signal.

The width dimension detecting means 9 detects the width dimension of the stitch 4 based on the input binary width signal e. Specifically, as shown in FIG. 7, the width dimension of the stitch 4 is detected based on how many reference pulses f are counted within the width of the binary width signal e.

The width of the seam 4 detected by the width detecting means 9 is input to the judging means 11 together with the width of the regular seam from the normal width storing means 10.
In step 1, the two width dimensions are compared to determine whether or not skipping occurs.

Specifically, as described above, the regular seam 4
If the width dimension of the seam 4 is, for example, 2 mm, an allowable range of 1.5 to 2.5 mm is set, and when the width dimension of the stitch 4 detected by the width dimension detecting means 9 falls outside this allowable range. It is determined that there is a skip.

In practice, even if it is determined that one image 7 (see FIG. 2) is skipped, no drive signal is output from the controller 17 shown in FIG. The drive signal is output only when it is determined that a plurality of (for example, five) images 7 are skipped continuously. As a result, the accuracy of detecting the presence or absence of skipping can be further stabilized.

The distribution mechanism 16 is provided with a controller 17
As shown in FIG. 4, the swing flap 24 normally located at the solid line position swings upward to the chain line position. As a result, the bags 1 sent out from the two feed belts 21 and 22 are discharged to the lower side of the swing flap 24, and are sorted into non-defective products and defective products.

Thus, based on the image signal captured by the camera 6, a detection signal is generated by the detection signal generation means 8, and the width dimension of the seam 4 is detected by the width dimension detection means 9 based on the detection signal. This width dimension and normal width storage means 1
The width of the regular seam 4 from 0 is compared with the width of the regular seam 4 by the determination means 11 to determine the presence or absence of skipping.
The skipping of the seam 4 can be detected accurately with a simple device configuration.

In the above-described embodiment, the skipping detection at the lower end of the bag body 2 with respect to the seam 4, that is, the skipping detection in the bag manufacturing process has been described. The present invention can be similarly applied to jump detection, that is, skip jump detection in the step of filling the contents.

FIG. 8 shows an example of a stitch skip detecting device applied to the step of filling the contents. In the figure, reference numeral 1 denotes a bag in which the contents 30 are filled in the bag body 2. The bag 1 is transported by the transport line 35 to the top sewing machine mechanism 4.
2, and the perforated portion 33 at the upper end of the bag body 2 is sewn with a sewing thread.

The top sewing machine mechanism 42 of the transport line 35
As shown in FIG. 8, a beam sensor 13, a light 14, a camera 6, and the like are provided on the downstream side, and the perforated portion 33 detects a stitch skip of the seam (not shown). It is supposed to be. Then, based on the detection result, the switching plate 47 of the sorting mechanism 46 disposed at the downstream end of the transport line 35 is switched, whereby the non-defective product is changed to the non-defective product line 48 and the defective product is changed to the defective product line 49. , Respectively. In other respects, the configuration is the same as that of the first embodiment, and the operation is the same.

Thus, even when the present invention is applied to the process of filling the contents, the same effect as in the case of the bag manufacturing process can be expected.

It should be noted that, in both of the above embodiments, FIG.
As described above, the case where the portion of the seam 4 is continuously captured by the camera 6 as the image 7 having a predetermined width in the transport direction has been described.
The image 7 of the seam 4 may be intermittently captured by the camera 6.

In the above-described embodiments, the case has been described where the image signal from the camera 6 is differentiated to make the edge of the stitch 4 visible, but the detection corresponding to the stitch 4 can be performed without the differentiation process. If a signal can be extracted, the differentiation processing may be omitted.

In the above-described embodiments, the width of the regular stitch 4 without skip is calculated based on the width of the stitch 4 in each image 7, and this value is stored in the normal width storage 10. Although the description has been given of the case where the width is set, the worker may measure the width of the seam 4 and store the measured value as the width of the regular seam 4 without skipping.

In the above-described embodiments, the detection device applied to the transport lines 5 and 35 has been described. For example, the inspection table 20 is used as an adapter for the sewing machine mechanism 1.
2, 42 may be directly attached.

Further, in both of the above embodiments, the case where the good and bad products are sorted by the sorting mechanisms 16 and 46 has been described. However, instead of the sorting mechanisms 16 and 46, a method such as a tape is used. It is also possible to provide a mechanism for giving an identification mark only to defective products and distinguishing them from non-defective products.

[0046]

As described above, according to the present invention, the width of the stitch detected by the width detecting means is compared with the width of the regular stitch having no skip to determine the presence or absence of skip. Thus, the stitch skip can be detected accurately with a simple device configuration, and the device can be manufactured at low cost.

According to the present invention, an end detecting sensor for detecting the leading end and the trailing end of the bag body and a feed amount detecting sensor for detecting the conveying distance of the bag are provided. Is activated when the feed amount detection sensor detects an arbitrary set transport distance after detecting the leading end of the bag body in the transport direction, and feeds after the end detection sensor detects the end of the bag body in the transport direction. Since the amount detection sensor stops when an arbitrary set transport distance is detected, the start and end of the inspection can be accurately set for the seam of each bag, and unnecessary parts can be inspected. By not doing so, the inspection accuracy can be improved.

According to the present invention, a distribution mechanism for distributing non-defective products and non-defective products based on an output signal from the determination unit is provided downstream of the imaging unit of the conveyance unit. And defective products having skips can be reliably sorted out, and work in the subsequent process is easy.

Further, according to the present invention, a mechanism for providing an identification mark to a defective product based on an output signal from the judging device is provided downstream of the imaging device of the transporting device. It can be clearly distinguished, and work such as rework is easy.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a stitch skip detection device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a range of an image captured by the camera in FIG. 1;

FIG. 3 is an explanatory diagram showing a specific example of the device of FIG. 1;

FIG. 4 is a side view showing an assembled state of the camera and the like in FIG. 3 on an inspection table.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is an explanatory diagram showing a relationship between a beam sensor and a camera.

FIG. 7 is an explanatory diagram illustrating an example of signal processing in a detection signal generation unit and a width dimension detection unit.

FIG. 8 is an explanatory diagram showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 bag 2 bag main body 3,33 perforation part 4 seam 5,35 conveyance line 6 camera 7 image 8 detection signal generation means 9 width dimension detection means 10 regular width storage means 11 judgment means 12 sewing machine mechanism 13 beam sensor 15 rotary encoder 16 , 46 distribution mechanism 20 inspection station 23 air nozzles 30 contained goods 42 top part sewing machine mechanism L _1, L ₂ the distance L ₃ dimensions a picture signal b, c differential signal d 2 value signal e 2 width signal f reference pulse

Claims (4)

[Claims] 1. A transporting means for transporting a bag formed by sewing a perforated portion formed at an end of a bag body with a sewing thread in the longitudinal direction of a seam; An imaging unit that captures an image of a predetermined width in the transport direction intermittently or intermittently; a detection signal generation unit that generates a detection signal corresponding to a seam based on an image signal captured by the imaging unit; Width dimension detecting means for detecting the width dimension of the stitch based on the detection signal; normal width storage means for storing the width dimension of a normal stitch without skipping; width dimension of the stitch detected by the width dimension detecting means And a determining means for comparing the width dimension of the regular stitch from the regular width storage means to determine the presence or absence of a skipped stitch. 2. An image pickup means comprising: an end detection sensor for detecting a leading end and a terminal end of a bag main body in a conveyance direction; and a feed amount detection sensor for detecting a conveyance distance of the bag. After detecting the leading edge of the main body in the transport direction, it is activated when the feed amount detection sensor detects an arbitrary set transport distance, and after the end detection sensor detects the end of the bag body in the transport direction, the feed amount is detected. 2. The stitch skipping detection device according to claim 1, wherein the detection is stopped when the detection sensor detects an arbitrary set conveyance distance. 3. A downstream side of the image pickup means of the transport means,
3. The stitch skip detecting device according to claim 1, further comprising a sorting mechanism for sorting non-defective products and non-defective products based on an output signal from the determination means. 4. The transport means, on the downstream side of the imaging means,
3. The stitch skip detecting device according to claim 1, further comprising a mechanism for giving an identification mark to a defective product based on an output signal from the determination means.