JPH0217037Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a novel automatic seam detector.
A new type of seam detector that can reliably detect seams without contact, regardless of the thickness or color of the sheet, such as cloth, and without the need to make any modifications to the threads used to sew it. and is of great use to industries that process sheet-like rolled products such as textiles.

[Conventional technology and problems to be solved]

As is well known, the following methods are known as techniques for detecting seams in sheet materials.

B. Contact type A method in which a sensor is placed in contact with the fabric and detects changes in the thickness of the seam.

(b) Non-contact method A method in which metal powder is applied to the threads that sew together the seams, and a sensor detects the metal to detect the seams.

C. Non-contact type A magnet is attached near the seam and a sensor detects the magnet to detect the seam.

D. Non-contact method A method that uses fluorescent thread to sew the seams together and detects the fluorescence.

E. Non-contact type A photoelectric transmission detection method that directly irradiates light onto cloth and detects the amount of change in the transmitted light.

However, for the contact method mentioned in A above,
There is a risk of staining or damaging the sheet (cloth), and the non-contact methods mentioned above require special work on the sheet or thread, which requires extra work. It is a big burden in terms of production efficiency and production costs, and the non-contact method mentioned above requires delicate sensitivity adjustment depending on the background color and thickness of the sheet, and is completely useless for patterned materials. There were flaws.

The present invention was developed in view of the fact that the conventional technology for detecting seams in sheet materials does not have the above-mentioned drawbacks. The technical problem is to provide an automatic seam detector that can reliably detect seams with all kinds of sheets, regardless of its strengths or weaknesses.

[Means adopted to solve the problem]

The means adopted by the present inventor to solve the above problem will be explained below with reference to the accompanying drawings.

That is, the present invention has tension rollers 4, 4 that prevent wrinkles and bending of the sheet 2 that is continuously conveyed in a spread state; a sheet guide roller 3 that supports the conveyed sheet 2 at a predetermined level and allows it to pass through;
Laser light emitting/receiving type sensors 5, 6 which irradiate laser light in the forward or reverse flow direction to detect changes in the thickness of the seam 1 when the seam 1 passes through, and output an electric signal with a potential proportional to the amount of light shielded at that time; A separation circuit 7 extracts only the potential displacement corresponding to the amount of change in the thickness of the seam 1 from the electrical signal from this sensor and outputs it as a displacement signal; The displacement signal sent from the separation circuit 7 and the threshold value setting device 9 and a comparator 8 which outputs a seam detection signal only when the potential of the displacement signal is high by comparing the potential with the threshold value signal sent from the automatic seam detector. Since it is non-contact, there is no risk of staining or damaging the fabric, and it is not affected by the thickness, background color, or pattern of the sheet, and there is no need to apply special processing to the sheet or splicing yarn. The most important feature is that there is no such thing.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the accompanying drawings. Note that Fig. 1 is a side view of the device of this embodiment, and Fig. 2 is a side view of the device of this embodiment.
FIG. 3 is a partially enlarged perspective explanatory diagram illustrating a joint detection mechanism in a light-receiving type sensor projecting/light-receiving sensor.

In the drawing, the sheet 2 is sewn into a long piece at the seam 1. The sheet 2 passes over the upper circumferential surface of the sheet guide roller 3 disposed between the tension rollers 4, 4, and is conveyed in the direction.
If the thickness of the sheet 2 changes while passing over the upper circumferential surface of the sheet guide roller 3, the upper surface of the sheet momentarily rises at that location.

Those indicated by numerals 5 and 6 are laser light emitting/receiving type sensors, and the laser beam irradiated by the laser projecting element 5 enters the light receiving element 6 where it is photoelectrically converted, and the amount of incident light at that time is Outputs an electrical signal with a potential proportional to . As is clear from the illustrated example, the sensors 5 and 6 are spaced a small distance from the upper surface of the outer periphery of the sheet guide roller 3.
A light projecting element 5 is arranged to emit laser light from upstream to downstream along the sheet forward flow direction. Therefore, if the seam 1 of the sheet 2 passes above the outer periphery of the guide roller 3, the amount of laser light will decrease by the amount that the upper surface of the sheet is raised, and the potential of the electric signal will decrease.

The reference numeral 7 indicates a differentiator employed as a separation circuit. This separation circuit 7 performs differential processing on the electric signals inputted from the sensors 5 and 6, extracts only the displacement of the electric potential that fluctuates due to changes in the thickness of the sheet, and outputs this as a displacement signal.

What is designated by the reference numeral 8 is a comparator, which compares the potential of the displacement signal sent from the separation circuit 7 and the threshold value signal sent from the threshold value setting device 9, and determines when the potential of the displacement signal is high. Outputs a seam detection signal to.

Reference numeral 10 designates a signal delay circuit, which delays the seam detection signal output from the comparator 8 by a required timing and outputs the delayed signal.

The configuration of the device of this embodiment is generally as described above, but the sheet guide roller 3 in the device of this embodiment
The positional relationship between and the laser emitting/receiving type sensors 5 and 6 is as follows.
Due to the characteristics of this sensor, it must be installed in a location within the range that the laser beam passes through, and it must remain within the range even if it passes through a fabric seam or changes in fabric thickness. For this reason as well, the light emitting surfaces of the sensors 5 and 6 are large and the light receiving portions react sensitively. In addition, to prevent malfunctions, if there is dust or wrinkles, they will be detected as cloth joints, so in order to match the characteristics of the separation circuit described later to the characteristics of the displacement output of cloth joints, two or more laser light emitting and receiving sensors should be used. It is also possible to adopt means such as an electric circuit that is attached in a similar manner and output can be taken out as a joint output only when both sensors detect it simultaneously, or an adjustment of the attachment angle between the photoelectric sensor and the deflection prevention roller 3. . It is clear that the present invention can also be used to detect seams in sheet and linear forms, and both are naturally planned by the inventor of the present invention.

[Effects of this invention]

As explained above using the embodiment device, according to the present invention, a method is adopted in which the change in the thickness of the seam in the sheet is detected in a non-contact manner using a laser emitting/receiving sensor. There is no risk that the thread or sheet will be damaged, and it can be detected reliably without any special processing on the thread or sheet.

In addition, as long as the thickness and color pattern of the sheet are within the range that the laser beam passes through, it will not malfunction, greatly improving reliability as an automatic machine, saving labor, and providing high quality. It can be said that it is an ideal device in terms of production and product management.

[Necessity of this invention]

Currently, a continuous processing method is used in the shearing process, in which the worker visually observes the seam of the fabric and manually moves the shearing blade up and down as the seam approaches. The cloth speed in the shearing process is 20 to 30 m/min on average, so 1 cloth is 50 m/min.
In the case of meters, workers must raise and lower them once every two minutes. If a mistake is made during this lifting and lowering, there is a risk of damaging the shearing blade at the cloth joint or causing the shaft to become eccentric. By automatically detecting cloth seams, continuous production is possible without the operator having to pay attention to anything, so the technical significance of the completion of this invention is of great importance.

[Brief explanation of drawings]

FIG. 1 is a side view of the device of this embodiment, and FIG. 2 is a partially enlarged perspective explanatory diagram showing a mechanism of a cloth seam detection unit in the light emitting/receiving section of the laser light emitting/receiving sensor in the device of this embodiment. 1... Sheet joint (overlock, inner lock), 2... Sheet, 3... Sheet guide roller, 4... Tension roller, 5, 6... Laser emitting/receiving type sensor, 5... Laser emitting element ,6
... Light receiving element, 7 ... Separation circuit, 8 ... Comparator, 9
...Shiki value setter, 10...Signal delay device (output section).

Claims (1)

[Scope of utility model registration request] Tension rollers 4, 4 that prevent wrinkles and bending of the sheet 2 that is continuously conveyed in a spread state;
A sheet guide roller 3 disposed between or near the tension rollers 4 and 4 to support the conveyed sheet 2 at a predetermined level and allow it to pass; the seam 1 of the sheet 2 passes through the circumferential surface of this sheet guide roller. laser light emitting/receiving type sensors 5 and 6 which irradiate the thickness change of the seam with a laser beam in the forward or reverse flow direction and output an electrical signal with a potential proportional to the amount of light shielded at that time; a separation circuit 7 that extracts only the potential displacement corresponding to the amount of change in the thickness of the seam 1 from the signal and outputs it as a displacement signal; An automatic seam detector comprising a comparator 8 which compares the potential with an incoming displacement signal and outputs a seam detection signal only when the potential of the displacement signal is high.