JPH06109423A - Apparatus for detecting edge of traveling belt - Google Patents

Abstract

PURPOSE:To stably detect the edge position of a plate without increasing a maintenance load by a method wherein a semiconductor laser is used as a light source for a beam of light with which an edge part at a continuously traveling strip is irradiated in a prescribed effective field of view. CONSTITUTION:For example, an edge part at a steel belt S traveling inside a hermetically sealed continuous treatment installation 5 is irradiated, via a shielding glass 6 through a cylindrical lens, with a laser beam oscillated from a semiconductor laser 7 which is oscillated continuously at a high output of about 100 to 300mW as a laser beam provided with an effective field of view corresponding to the plate width of the steel belt S. At this time, the wavelength of the laser beam is selected at a value which is deviated form the absorption band of the glass, e.g. at 800nm. The laser beam with which the edge part is irradiated is reflected partly by the steel belt S, it is passed through the glass 6 again and it is incident on a CCD camera 2. The intensity of the laser beam which is incident on the camera 2 is proportional to the edge position of the steel belt. As a result, when the output of the camera is amplified by an amplifier 3, it is possible to obtain the signal of the edge position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge position detecting device for continuously running strips.

[0002]

2. Description of the Related Art A conventional plate edge position detecting method in a continuous strip processing apparatus is, for example, as shown in FIG.
A pair of the light source 1 and the detector 2 are installed on both sides (front side and back side) of the steel plate S, and the fact that the amount of light received by the detector 2 is proportional to the plate edge position is utilized (for example, Japanese Patent Publication No. 60). -41285, JP 62-14310, 62-
179601 publication). At this time, when a CCD camera is used as the detector, the resistance of the camera element changes in proportion to the amount of light. Therefore, if the obtained camera output is amplified by the amplifier 3, a voltage proportional to the steel plate edge position is output, Therefore, the edge position can be detected in real time.

A method of detecting an edge position when a material to be processed is running in a closed continuous processing facility such as a vacuum chamber or an annealing furnace is the same in principle as the above case, but has an optical system configuration. Somewhat different. That is, since it is difficult to install a light source and a detector in the closed continuous processing facility due to the facility design, normally, as shown in FIG. 2, the reflection plate 4 for reflecting light is closed. The light source 1 and the detector 2 are installed inside the equipment 5, while the light source 1 and the detector 2 are installed outside the closed continuous processing equipment, and the light reflected by the reflection plate 4 is received by the detector 2 through the shielding glass 6,
Further, the position of the steel sheet edge is detected by being amplified by the amplifier 3 (for example, Japanese Utility Model Publication No. 63-21554).

[0004]

However, the above conventional method has a problem in that it requires periodical replacement of the light source and periodical maintenance of the reflector as described below. 1) Periodical replacement of light source Normally, the light source is a fluorescent lamp or a halogen lamp, and it is necessary to replace it regularly every six months.
Maintenance costs are large along with running costs.

2) Periodic maintenance of the reflector In particular, when the reflector for detecting the edge position is installed in the closed type continuous processing facility, the edge position detection accuracy is deteriorated due to the dirt of the reflector and the like. In order to prevent this, periodical cleaning or replacement of the reflection plate is required at a frequency of about once every two weeks to one month, resulting in an increase in maintenance load. In addition, it is necessary to incorporate the reflector into the equipment, which causes problems in equipment design.

As described above, the conventional edge position detecting device cannot detect the edge position in a stable manner and cannot correct the meandering of the steel sheet, so that stable operation cannot be expected. The present invention advantageously solves the above problems,
Without increasing running costs and maintenance load,
It is an object of the present invention to propose an edge position detecting device for a traveling zone capable of stably detecting a plate edge position.

[0007]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies to solve the above problems, and when a semiconductor laser is used as a light source at that time, an unexpected result is achieved in achieving the intended purpose. I was able to get The present invention is based on the above findings.

That is, according to the present invention, a continuously traveling strip is composed of a semiconductor laser as a light source for irradiating the edge portion thereof with light in a predetermined effective field of view and a light receiver for receiving reflected light from the strip. It is a band edge position detecting device (first invention).

Further, according to the present invention, with respect to a strip continuously traveling in a closed continuous processing equipment such as a vacuum chamber or an annealing furnace, the strip is provided from outside the closed continuous processing equipment through a shielding glass provided in the processing equipment. , A semiconductor laser as a light source that irradiates the edge portion of the strip with light in a predetermined effective field of view, and is also installed outside the hermetically sealed continuous processing facility, and reflects light from the strip through the shielding glass. It is an edge position detecting device for a traveling zone (second invention), which comprises a light receiving device for receiving light.

In the present invention, as the semiconductor laser, a high output semiconductor laser having an output of 100 to 200 mW in continuous oscillation is suitable. Also, as the light receiver, CC
Although the D camera is particularly advantageously suited, it goes without saying that various conventionally known image sensors can be used. Furthermore, the measurement target in the present invention is not limited to a metal strip such as a hot rolled steel plate or a cold rolled steel plate, and any long strip such as a plastic film or roll paper can be used.

[0011]

In the present invention, since a semiconductor laser having a semi-permanent life is practically used as a light source, periodic replacement of the light source is unnecessary, and sufficient reflected light can be obtained from the steel plate. Conventionally, a reflector that is inevitable when detecting an edge position in a closed continuous processing facility is also unnecessary.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Since the structure of the first invention is included in the structure of the second invention, only the second invention will be described here. Figure 3
A preferred example of the edge position detecting device according to the second invention is shown in a perspective view, and in FIG. The skeleton of the configuration is the same as in the case of FIG. 2 described above, and therefore is shown with the same numbers, and in the figure, the number 7 is a semiconductor laser.

Now, as shown in FIGS. 3 and 4, the laser light emitted from the semiconductor laser 1 passes through a cylindrical lens 8 and has an effective field of view corresponding to the plate width of the steel strip S, as shown in FIG. Shielding glass 6 as light
The edge portion of the steel strip S running through the closed continuous processing facility 5 is irradiated via the. Here, the wavelength of the laser light is selected to be a value outside the absorption band of the shielding glass 6 (for example, 800 nm). A part of the laser beam applied to the edge portion of the steel strip is reflected by the steel strip S, passes through the shielding glass 6 again, and enters the CCD camera 2. Since the intensity of the laser light entering the CCD camera 2 is proportional to the steel strip edge position, the edge position signal can be obtained by amplifying the camera output with the amplifier 3.

The laser light applied to the area other than the edge of the steel strip is usually absorbed by the inner wall of the hermetically sealed continuous processing facility. However, when the material of the inner wall reflects the laser light, the part to which the laser light is applied is irradiated. The inner wall of is slightly inclined so that the light reflected by the inner wall does not enter the CCD camera 2. Further, in order to prevent the disturbance due to the reflected light from the front and back surfaces of the shielding glass 6, it is preferable that the shielding glass 6 is also provided with a slight inclination so that the reflected light does not enter the CCD camera 2.

[0015]

The effects of the present invention are as follows. 1) In practice, since a semiconductor laser having a semi-permanent life is used as a light source, periodical replacement of the light source is unnecessary, which improves maintenance and reduces running cost. 2) Since the high-power semiconductor laser is the light source, it is possible to obtain a sufficient amount of reflected light from the object to be processed. Therefore, the conventional reflector that is inevitable when detecting the edge position in the closed continuous processing equipment is used. It becomes unnecessary, the design and manufacturing cost of the closed continuous processing equipment can be suppressed, and the maintenance of the reflector is not necessary. 3) Since this device has a low maintenance load and can detect the steel plate edge stably, it can be used as the edge position detection in the vacuum chamber and the detection end of the meandering correction device in the annealing furnace. Since the reflector plate becomes dirty, it can be used as a meandering sensor in a continuous annealing furnace in a special atmosphere where it has been impossible to detect meandering of a steel plate.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a conventional plate edge position detection device.

FIG. 2 is a schematic diagram of a plate edge position detecting device for a strip that is running in a conventional closed continuous processing facility.

FIG. 3 is a perspective view of a plate edge position detecting device for a strip running in a closed continuous processing facility according to the present invention.

FIG. 4 is a partial cross-sectional view of a plate edge position detecting device for a strip running in a closed continuous processing facility according to the present invention.

FIG. 5 is an enlarged view of the inside of the semiconductor laser device.

[Explanation of symbols]

 1 Light Source 2 Detector 3 Amplifier 4 Reflector 5 Closed Continuous Processing Equipment 6 Shielding Glass 7 Semiconductor Laser 8 Cylindrical Lens

Claims (2)

[Claims] 1. A semiconductor laser as a light source for irradiating an edge of a continuously traveling strip with a predetermined effective field of view, and a photodetector for receiving the reflected light from the strip. Edge position detection device for running zone. 2. A strip that continuously runs in a closed continuous processing facility such as a vacuum chamber or an annealing furnace, and the strip is provided from outside the closed continuous processing facility through a shielding glass provided in the processing facility. A semiconductor laser as a light source for irradiating light with a predetermined effective visual field to the edge portion of, and similarly installed outside the closed continuous processing facility, through the shielding glass,
An edge position detection device for a traveling zone, comprising: a light receiver for receiving the reflected light from the strip.