JPH04157589A - Bar stock counting method - Google Patents

Abstract

PURPOSE:To accurately count the number of bar stocks by adopting a laser photoelectric switch as a diffuse reflecting type photoelectric switch. CONSTITUTION:A carried steel tube P is detected by first and second laser photoelectric switches 30A and 30B and when it is detected by at least one of the two laser photoelectric switches, the steel tube P is counted by an OR circuit 32. Since the positional relationships between a light emitting part 34 and a light emitting part 36 are reversed between the first laser photoelectric switch 30A and the second laser photoelectric switch 30B, the same allowable range of measurement for the laser photoelectric switches can be used for detection even when the steel tube P is inclinated in either of the right-down and left-down directions as shown in the figure. Thus, the number of bar stocks can be accurately counted.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for counting strips, such as steel pipes, which can accurately count the number of strips.

[Conventional technology]

Conventionally, as shown in FIG. 7, the method of counting the number of steel pipes is to irradiate the surface of the steel pipe P with light from a light source lamp 10 through a projection lens 12, and to collect specularly reflected light from the surface. There is a method in which light is received by a detection cell 16 through a light receiving lens 14 and counting is performed by turning on and off the detection cell. However, the above method has the following two problems. (1) If the position of the II pipe changes due to bending or the like, or if the steel pipe P has a large inclination, a sufficient amount of reflected light will not enter the detection cell 16 through the light receiving lens 14. Unable to count (miscount)
Sometimes. (2) @If the surface of the tube P has rust or water has adhered to it and the surface quality has changed, the intensity of the reflected light may be insufficient and miscounts may occur as well. Therefore, in order to prevent the above-mentioned miscount, a method has been proposed in JP-A No. 50-28374, in which the surface of the steel pipe is coated with paint to make the reflection state uniform. Furthermore, Japanese Patent Laid-Open No. 50-36180 proposes a method of receiving and counting specularly reflected light from the surface of a steel tube using a reflective phototube that has a light emitting part and a light receiving part integrated. Furthermore, methods of counting using proximity switches are also known.

[Problem to be solved by the invention]

However, according to the method proposed in JP-A-50-28374, although the above problem (2) is solved, it takes time and effort to apply paint to the steel pipe and remove it, and it is uneconomical. It is. Further, depending on the method proposed in JP-A-50-36180, for example, if the inclination of the steel pipe is large, it will be miscounted, so the problem (1) is not solved, and the problem (2) is not solved at all. Furthermore, when a proximity switch is used, the problem in (1) above is not improved at all; rather, it becomes easier to miscount, and this method also has the problem that non-magnetic steel pipes cannot be counted. There is also. The present invention was made to solve the above-mentioned conventional problems, and even if the strip material such as a steel pipe is bent or inclined, rust may occur on the surface of the strip material. It is an object of the present invention to provide a method for counting strips that can accurately count the number of strips even when the number of strips is counted.

[Means to solve the problem]

In the present invention, at least one pair of diffuse reflection type photoelectric switches are disposed in the length direction of the strip to be measured, and multiple pairs of photoelectric switches are arranged so that the arrangement direction of the light emitting part and the light receiving part is in the length direction of the strip. and the positional relationship between the two is opposite to each other, and for each photoelectric switch, light is irradiated from the light emitting part to the surface of the strip material, and the reflected and diffused light is detected by the light receiving part. The above object is achieved by counting the number of strips when at least one photoelectric switch detects reflected and diffused light for each of multiple pairs of photoelectric switches. Further, the present invention achieves the above object reliably by using a laser photoelectric switch as the diffuse reflection type photoelectric switch.

[Effect]

The present inventor conducted an experimental test to learn the characteristics when a laser photoelectric switch is applied to the counting of steel pipes (strips), and as a result of various studies, the following knowledge was obtained. FIG. 2 is a schematic perspective view showing test conditions for a laser photoelectric switch. The measurement targets are 2111ra1 (φ) and 160in
Using two steel pipes (φ), each was placed on a base 20, and measurements were performed under different conditions using a laser photoelectric switch 22 installed at a position of 403 inches above the base 20. The laser photoelectric switch is model E3 manufactured by Omron.
L-DS50E4 (diffuse reflection type) was used. Under the above conditions, when the arrangement direction of the light emitting part and the light receiving part of the laser photoelectric switch 22 was made to match the length direction of the steel pipe P, and the steel pipe P was moved in the lateral direction as shown in FIG.
In the case of 111+1 (φ), approximately ± from the center surface of the steel pipe P
If it deviates by 0.5 nm, it becomes undetectable, and if it deviates by 160 nn (
In the case of φ), it became undetectable when the deviation was approximately ±2.51Wl. Also, under the same conditions, as shown in Figure 4, two 21
When measurements were taken while moving the in+ (φ) steel pipes P in close contact with each other in the direction of the arrow, it was not possible to stably detect each of the two steel pipes P. In addition, as shown in FIG. 5(A), the steel pipe P is aligned in the arrangement direction of the light emitting part and the light receiving part of the laser photoelectric switch (indicated by the - dotted chain line).
When the steel pipe P was tilted horizontally and moved in the direction of the arrow and measured in the same manner, stable detection was possible even when the angle between the arrangement direction and the steel pipe P exceeded 25°.
When two steel pipes P are brought into close contact with each other, as in M(B), stable detection is only possible up to approximately 25°. Furthermore, as shown in FIG. 6(A), with the arrangement direction of the light emitting part and the light receiving part aligned with the length direction of the steel pipe P, the steel pipe P is tilted vertically so that the light emitting part side is higher. When measured, it was possible to detect angles of inclination up to about 134 from the horizontal plane, but on the contrary, as shown in Figure (B),
The steel pipe P is #1 so that the light receiving part side is higher. When tilted, detection was impossible if the tilt angle exceeded about 3°. Based on the above knowledge, in the present invention, for example, two diffuse reflection type photoelectric switches each having a laser emitting part are set as a set, and two photoelectric switches in each village are used to measure the length of surplus materials such as steel pipes. They are placed approximately parallel to each other in the horizontal direction. Note that, for convenience, the following description will be based on a case where a pair of photoelectric switches are used. As mentioned above, the two photoelectric switches are disposed approximately in line with each other in the length direction of the strip, and when at least one of the photoelectric switches is activated, the remaining material is counted, so that the strip is not bent. Even if the position of the extra material has changed (deviated from its original position) in the length direction of the strip due to reasons such as Seven-pointed, which makes it possible to count the number of pieces.
At the same time, the two photoelectric switches mentioned above are arranged so that the arrangement direction of the light emitting part and the light receiving part coincides with the length direction of the strip material, and the positional relationship between them is opposite to each other. It is possible to significantly reduce miscounts caused by vertical inclination of the material. That is, using FIG. 6 as an example, if there is only one laser photoelectric switch, it is possible to detect up to about 13 degrees on one side as shown in FIG. Approximately 3 as in (B)
However, since the same laser photoelectric switch is arranged in the opposite direction to that shown in FIG. 6, detection up to approximately 13 degrees is possible even in the case shown in FIG. 6(B). As described above, according to the present invention, it is possible to reliably detect the steel pipe over a wide range of inclination angles, regardless of which direction the vertical inclination of the strip is. Furthermore, in the present invention, since reflected diffused light is detected instead of specularly reflected light, it is possible to detect the strip material without being affected by the surface properties of the remaining material.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing the main parts of a counting device applied to a method for counting strips according to an embodiment of the present invention. The counting device includes a pair of first and second laser photoelectric switches 30A and 30B, and both laser photoelectric switches 3OA and 30B are connected to the main body of the device (not shown) via an OR circuit 32. There is. The first and second laser photoelectric switches 30A and 30B are diffuse reflection type laser photoelectric switches (model E3L-DS5 manufactured by Omron Corporation).
0E4) can be used. Note that the emission wavelength of this laser photoelectric switch is in the infrared region. In this embodiment, both the laser photoelectric switches 30A, 30
B is a steel pipe P being conveyed on a skid (not shown)
It is placed at a predetermined height above and in the length direction of the steel pipe P. For example, this height is 500111
It can be as follows. Further, both of the laser photoelectric switches 30A and 30B are arranged such that the arrangement direction of the light emitting section 34 and the light receiving section 36 coincides with the longitudinal direction of the steel pipe P in a normal state. However, both the laser photoelectric switches 30A, 3
In 0B, the positional relationship between the light emitting section 34 and the light receiving section 36 is reversed. That is, in FIG. 1, the second laser photoelectric switch 30A
In this case, the light emitting section 34 is on the left side, the light receiving section 36 is on the right side,
Conversely, in the second laser photoelectric switch 30B, the light emitting section 34 is on the right side and the light receiving section 36 is on the left side. According to this embodiment, the steel pipe P being conveyed is detected by the first and second laser photoelectric switches 30A and 30B, and the OR circuit 32 detects when at least one laser photoelectric switch detects the steel pipe P. counts the steel pipes P. Therefore, even if the steel pipe P is bent or otherwise displaced from its original position, counting can be performed reliably without miscounting. Furthermore, in the first laser photoelectric switch 30A and the second laser photoelectric switch 30B, the positional relationship between the light emitting part 34 and the light receiving part 36 is reversed, so that the @tube P is located downward to the right and downward to the left in the figure. No matter which direction it is tilted, it can be detected within the measurement tolerance range of the same laser photoelectric switch. Therefore, miscounts can be prevented and counting accuracy can be improved. Further, in this embodiment, the first and second laser photoelectric switches 30
Since both A and 30B can detect diffusely reflected light, the counting accuracy can be significantly improved compared to the case where specularly reflected light is detected, and at the same time, mistakes can be avoided even when rust has formed on the surface of the steel pipe. You can count without counting. In addition, in this example, since a laser photoelectric switch is used as the photoelectric switch, the intensity of the reflected light from the steel pipe surface is large, and the detection accuracy is high. Therefore, it is also possible to count small diameter steel pipes with high accuracy. . Although the present invention has been specifically explained above, it goes without saying that the present invention is not limited to what is shown in the above embodiments, and can be modified in various ways. For example, the photoelectric switch applicable to the present invention is not limited to the laser photoelectric switch, and the light emitting part is
It may also be equipped with an ED. Alternatively, the irradiation light to be used is not limited to infrared or red as in the example, but reflective light may be used when there is water attached to the surface of the steel pipe or when counting is performed in an environment with a lot of water vapor in the surrounding area. In order to prevent light from being absorbed by water, it is preferable to use blue or green laser light. In addition, if water is attached to the surface, if the water is removed by air purge etc. in advance, it is possible to perform accurate counting using infrared light in the same machine as in the above example. can. In addition, objects that can be counted by the present invention are not limited to steel pipes, but can also be solid 11 steel or other long strip materials, as long as the state of reflection of light irradiated onto the surface changes. , any thing can be counted. Furthermore, the present invention is not limited to the case where a pair of photoelectric switches are used as in the embodiments described above, but a plurality of pairs of photoelectric switches may be used by arranging them in parallel in the same direction.

【Effect of the invention】

As described in detail above, according to the present invention, even if a strip such as a steel pipe is bent or inclined, or even if rust occurs on the surface of the strip, the surface Even if the properties are not suitable for specular reflection of light, the number of strips can be counted with high accuracy.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the main parts of a counting device applied to one embodiment of the present invention, and FIGS. 2, 3, 4, 5, and 6 are all FIG. 7 is an explanatory diagram for explaining the conventional counting method in detail. 30A...Second laser photoelectric switch, 30B...Second laser photoelectric switch, 32...OR circuit,
34... Light emitting section, 36... Light receiving section,
P...Steel pipe.

Claims (2)

[Claims] (1) At least one pair of diffuse reflection type photoelectric switches are arranged in the length direction of the strip to be measured, and each pair of photoelectric switches is arranged so that the arrangement direction of the light emitting part and the light receiving part is in the length direction of the strip. arranged so that they coincide and the positional relationship between the two is opposite to each other, and for each photoelectric switch, irradiates light from the light emitting part to the surface of the strip material, and detects the reflected and diffused light with the light receiving part, A method for counting strips, comprising counting the number of strips when at least one of the photoelectric switches in each pair detects reflected and diffused light. (2) The method for counting strips according to claim 1, wherein the diffuse reflection type photoelectric switch is a laser photoelectric switch.