JP2799019B2 - Rolling path inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a rolling path inspection method for detecting the presence or absence of an abnormality in a rolling path configured by arranging rolling rolls in multiple stages.

(Prior Art) A multi-way roll multi-high rolling mill used for rolling of a material is provided with a rolling passage constituted by arranging rolling rolls in multiple stages, and a work material is passed from the inlet to the outlet on the rolling passage. In the process of moving the workpiece, the cross section of the workpiece is reduced stepwise by being passed between the rolling rolls of each stage to perform rolling.

However, in the rolling passage of this multi-roll multi-high rolling mill, if a breakage of the work material occurs during the rolling process and fragments of the work material remain in the passage, the passage of the work material is interrupted and the rolling process is performed. Therefore, there is provided a rolling passage inspection / detection device for inspecting whether there is an undesired object such as a piece of a work material in the rolling passage or not, for example, whether there is an abnormality or not.

Conventionally, in order to perform an inspection of a rolling path, a laser light projector that irradiates a laser beam from an outlet side to an inlet side of a rolling path configured by arranging rolling rolls in multiple stages,
A laser light irradiation angle setting device for setting an irradiation angle of the laser light irradiated from the laser light projector; and a laser light irradiation device provided adjacent to an entrance of the rolling passage and receiving laser light irradiated from the laser light projector to change a state of the rolling passage. An inspection apparatus including a laser light receiver to be inspected is used.

This rolling passage inspection device irradiates the rolling passage with laser light from the exit side by a laser beam projector, sets the irradiation angle of the irradiated laser light by an angle setting device, and controls the laser light passing through the rolling passage. At the entrance side, laser light is received by the laser light receiver.Unnecessary objects are not present in the rolling path compared with the laser light reception level of the laser light receiver in the normal case where there is no unnecessary substance in the rolling path. Since the level of laser light received by the laser light receiver drops when there is an abnormality, such as the presence of the laser light, the laser light receiver outputs an abnormality detection signal in response to the decrease in the light reception level, and there is an abnormality in the rolling path. You are inspecting it.

In the inspection of the rolling passage, when the rolling process is continuously performed by the roll multi-high rolling mill, the state of the rolling passage is inspected by using an inspection device from time to time during the rolling process.

(Problems to be Solved by the Invention) However, the conventional rolling path inspection apparatus erroneously detects when the state of the rolling path is inspected during the rolling process, and the state of the rolling path is abnormal. Despite the presence of abnormalities such as unnecessary objects, the condition of the rolling path is normal, that is, it is determined that there are no abnormalities such as unnecessary things in the rolling path, and the laser light receiver detects the abnormality detection signal. May not be output, and it may not be possible to detect the presence of an unnecessary object in the rolling path.

As described above, when the rolling passage inspection device cannot detect an abnormality in the rolling passage, the workpiece collides with an unnecessary material existing in the rolling passage when moving and passing through the rolling passage, and the work Further, an accident such as deformation or breakage of the rolling roll itself occurs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly reliable rolling path detection device free from erroneous detection.

[Structure of the Invention] (Means for Solving the Problems) The inventor of the present invention has carried out various studies on the cause of erroneous detection in the rolling path inspection device. As a result, the inventors have found that the following points can be cited as causes of the erroneous detection.

 One of the causes is as follows.

Before inspecting the rolling path by the inspection device,
As shown in the figure, when there is no abnormality in the rolling path, a laser beam is emitted from the laser path to the rolling path by the laser beam projector, and the laser beam is received by the laser beam receiver. I do. Then, a light receiving level (in the range of 1 to 99%) of a predetermined ratio with respect to the normal light receiving level (100%) A is set as an abnormality detection level B which has detected an abnormal state in which an unnecessary object is present in the rolling path. ing. That is, when an abnormality is present in the rolling path, for example, when an unnecessary object is present, the rate at which the laser beam emitted from the laser beam projector is blocked by the unnecessary object when passing through the rolling path and reaches the light receiver decreases, and The light receiving level at the time of reaching the level is lower than the light receiving level A when the rolling path is normal. For this reason, the abnormality detection level B is set in consideration of the decrease. These light receiving levels A and B are set in a normal temperature state.

However, when rolling is performed by a rolling mill, the surface temperature of the rolling roller increases because the workpiece is generally heated. When the surface temperature of the rolling roller rises, a reflection state of the laser light passing through the rolling path with the rolling roller and fluctuation of the laser light occur, and as shown in FIG. The light reception level of the laser beam when the laser beam reaches the laser beam receiver at the normal temperature state passes through the rolling passage and reaches the laser beam receiver, which rises.
Particularly in the case of hot working, the above tendency is large because the surface temperature of the rolling roller is high. For this reason, as shown in FIG. 7, depending on the degree of increase of the actual light receiving level with respect to the initial light receiving level, the actual light receiving level may be lower than the initially set abnormal detection light level even if there is an unnecessary object in the rolling path. It has been found that the light receiving level Bb may be higher than B, and may be erroneously determined to be normal.

Therefore, the inventor of the present invention has studied countermeasures against this cause, and found that when the actual light receiving level increases, it can be dealt with by setting the increased actual light receiving level to a new normal light receiving level. .

 Other causes are as follows.

When rolling is performed by a rolling mill, the surface temperature of the rolling roller increases due to friction between the rolling roller and the workpiece.
When the surface temperature of the rolling roller rises, a reflection state of the laser light passing through the rolling path with the rolling roller and fluctuation of the laser light occur, and an image of the laser light when reaching the laser light receiver is irradiated from the laser light projector. The image of the laser beam may be deformed, and the brightness may be non-uniform, resulting in shading.

When this phenomenon was confirmed, it was found that the laser light receiver became more remarkable as the distance from the entrance of the rolling path increased. This is because a part of the laser beam is reflected on the rolling roll, so that the contour of the laser beam image is maintained in the rolling path, but when the laser beam goes out of the rolling path, the laser beam is opened and the laser beam is opened. Since the laser light emitted from the projector is spread at a fixed irradiation angle by the angle setting device, the laser light expands and the brightness decreases as the laser light receiver moves away from the entrance, and the deformation of the image and the difference in density Turned out to be enlarged. If the image of the laser beam reaching the laser beam reception is unstable in this way, it becomes difficult to determine the presence or absence of an unnecessary object in the rolling path, and it is erroneously determined that the object is normal even when the unnecessary object exists in the rolling path. I found out.

The inventor has conducted various studies on measures against this cause, and as a result, by positioning the laser light receiver as close as possible to the entrance of the rolling path, the deformation of the image of the laser light received by the laser light receiver is improved. It has been found that generation of light and shade can be suppressed as much as possible.

The rolling path inspection method of the present invention, a laser beam is emitted from the exit side to the entrance side to the rolling path configured by arranging rolling rolls in multiple stages by a laser beam projector, the laser at the entrance side of the rolling path In the method of inspecting the state of the rolling path by receiving the laser light by the light projector, first, a normal light receiving level at which the laser light emitted from the laser light projector is received by the laser light receiver when the rolling path is normal is set. And when the received light level of the laser light received by the laser light receiver becomes higher than the initially set normal received light level, this higher received light level is set as a new normal received light level. It is.

In other words, in the rolling path inspection method, when the received light level of the laser light received by the laser light receiver becomes higher than the initially set normal received light level during the inspection, the high received light level is changed to a new normal received light level. By setting the level, it is possible to compensate for the influence of the fluctuation of the laser beam or the change in the reflection state due to the temperature rise of the rolling roll on the light receiving level, and to perform a highly accurate inspection.

The rolling path inspection device of the present invention, a laser beam projector for irradiating a laser beam from the exit side to the entrance side to the rolling path configured by arranging rolling rolls in multiple stages, and irradiating from this laser beam projector A laser light irradiation angle setting device that sets an irradiation angle of laser light, and a laser light receiver that is provided close to the entrance of the rolling passage and receives laser light irradiated from a laser light projector to detect a state of the rolling passage. It is characterized by having.

In other words, in this rolling path inspection device, by providing the laser beam receiver near the entrance of the rolling path, the laser beam is received before the deformation or shading in the image of the laser beam received by the laser beam receiver increases. Thus, highly accurate detection can be performed.

The laser light receiver is separated from the optical axis of the laser light when rolling is performed in the rolling path, and is moved on the optical axis of the laser light when detection is performed. The laser beam receiver can be provided close to the entrance of the rolling path without hindering the movement of the laser beam.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The configuration of the rolling passage inspection apparatus used in the present embodiment will be described with reference to FIGS.

First, a multi-roll multi-high rolling mill 1 provided with a rolling passage inspection device as shown in FIG. 1 will be described. A plurality of rolling stands 2 having a plurality of rolling rolls (not shown) are arranged along a rolling line. The gap between the rolls in each stage of the rolling stand 2 from the inlet 3 to the outlet 4 of the workpiece is gradually reduced in accordance with the reduction ratio of the cross section of the workpiece. Each is connected to form a rolling path 5. Reference numeral 6 denotes a workpiece removing device provided in front of the outlet 4 of the rolling passage 5 in the rolling mill 1.

Rolling path inspection device includes laser beam projector 11, angle setting device
12 and a laser light receiver 13 are provided. The laser beam projector 11 generates and irradiates a laser beam, for example, a gas laser beam. The laser beam projector 11 is a work material take-out device 6
, And a laser beam is emitted from the outlet 4 to the inlet 3 to the rolling passage 5 of the rolling mill 1 via the take-out device 6. The angle setting device 12 includes a collimator, and adjusts and sets the irradiation angle of the laser light emitted from the laser light projector 11. The laser light receiver 13 has, for example, a silicon photodiode light receiving element. Laser light receiver 13 is rolling mill 1
Is provided in front of the entrance 3 of the rolling passage 5 and receives the laser beam emitted from the laser beam projector 11 and passed through the rolling passage 5 to detect the presence of unnecessary material in the rolling passage 1. A display 14 and a light receiving level setting device 15 are connected to the laser beam receiver 13.

The laser beam receiver 13 is provided so as to be movable between a position near the entrance 3 in front of the entrance 3 of the rolling passage 5 in the rolling mill 1 and a position away from this position. As shown in FIGS. 2 to 4, a guide rod 16 is provided upright at a position in front of the entrance 3 of the rolling passage 5 and close to the entrance 3, and a support 17 is movable up and down on the guide rod 16. It is supported by. The support 17 is provided with, for example, a laser beam receiver 13 and a workpiece guide 18 separately in an upper stage and a lower stage. A hydraulic cylinder 19 is provided upright adjacent to the guide rod 16, and a piston rod 20 provided on the hydraulic cylinder 19 is connected to a support 17. Therefore, the piston rod 20 is raised or lowered by the driving of the hydraulic cylinder
Can go up and down.

The operation of the rolling passage detecting device thus configured will be described.

The case where the workpiece is rolled in the rolling mill 1 will be described.

At the time of rolling, as shown in FIGS. 2 and 3, the piston rod 20 of the hydraulic cylinder 19 is driven to
Is moved up and down along the guide rod 16 to position the workpiece guide 18 on the axis of the guide passage 5. At this time, the laser light receiver 13
Is located at a lower position away from the axis of the rolling passage 5. Then, the workpiece is fed from the inlet 3 to the rolling path 5 and moved toward 4, and in the process, the workpiece is reduced stepwise through the gaps of the rollers provided at the rolling stands of each stage, and the outlet 4
Sent from.

A basic method for inspecting the rolling passage 5 will be described.

At the time of inspection, as shown in FIG.
The support 17 is moved up and down along the guide rod 16 by driving the piston rod 20 of FIG.
Is positioned on the axis of the rolling passage 5 at a position close to the front of the rolling path 5.

In this way, the laser beam receiver 13 is moved to a position away from the entrance 3 of the rolling passage 5 during rolling, and is moved to a position close to the entrance 3 of the rolling passage 5 during inspection of the rolling passage 5 as described later. Accordingly, the laser beam receiver can be provided close to the entrance of the rolling passage without disturbing the movement of the workpiece during rolling. In conventional inspection equipment,
In order to feed the workpiece into the rolling path 5 from the inlet 3, a laser beam receiver 13 was provided far away from the inlet 3 and the front side of the inlet 3 was widely open. For example, in the conventional inspection device, the entrance 3
The distance S2 between the laser light receiver 13 and the laser light receiver 13 was 5 m, but the distance S1 between the entrance 3 and the laser light receiver 13 is 25 cm in the inspection apparatus of the present embodiment.

As shown in FIG. 1, a laser beam is radiated by a laser beam projector 11 onto a guide passage 5 from an outlet 4 to an inlet.
The laser beam emitted by the laser beam projector 11 passes through the angle setting device 12 and is set to an irradiation angle corresponding to the cross-sectional reduction ratio of the workpiece in the rolling passage 5.
to go into. The laser beam spreads at a predetermined angle when passing through the guide passage 5 and passes through the gap between the rolls of the rolling stands 2 at each stage. The laser beam that has passed through the rolling path 5 exits from the entrance 3, and the laser beam receiver 13 that is located close to the entrance 3 outside.
And the light is received by the laser light receiver 13. Here, when there is no unnecessary material such as a work material in the rolling path 5, the laser beam emitted from the laser projector 11 passes through the rolling path 5 without being interrupted and passes through the laser beam receiver 13 Reach When there is an unnecessary object such as a work material in the rolling passage 5,
The laser beam emitted from the laser beam projector 11 is applied to the rolling path 5
When passing through the laser light receiver is partially blocked by unwanted objects
Reach 13 When the laser beam receiver 13 receives the laser beam partially blocked by an unnecessary object, it outputs a signal indicating that an abnormality has been detected. The display 14 receives a signal from the laser beam receiver 13 and indicates that an unnecessary object is present in the rolling path 5. The operation of the laser light receiver 13 is such that the light receiving level of the laser beam passing through the rolling passage 5 when the undesired material does not exist in the rolling passage 5 is set to 100. Since the light receiving level of the laser light passing through the light receiving element decreases, the decrease in the light receiving level is measured and an abnormality detection signal is output.

Further, it is also possible to provide a protection device which does not leave the guide passage 5 unless the laser beam receiver 13 is reset from the outside and prevents mistakes in charging the next workpiece.

Next, a method of inspecting the rolling path 5 of the rolling mill 1 using the rolling path inspection apparatus will be described with reference to a flowchart shown in FIG.

First, a light receiving level 0 when no laser light is received is set in the laser light receiver 13 (FIG. 5, SP1). Prior to the inspection of the rolling passage by the inspection device, the rolling passage is irradiated with laser light by a laser beam projector and received by a laser light receiver in a state where there is no unnecessary material in the rolling passage as shown in FIG. Then, the light receiving level of the laser beam at this time is set as a normal light receiving level A (FIG. 5, SP2). Then, a light receiving level at a predetermined ratio (for example, in the range of 1 to 99%) with respect to the normal light receiving level (100%) A is set as an abnormality detection level B which has detected an abnormal state in which an unnecessary object is present in the rolling path. (Fig. 5, SP3). That is, when an unnecessary material is present in the rolling path, the rate at which the laser light emitted from the laser beam projector is blocked by the unnecessary material when passing through the rolling path and reaches the light receiver decreases, and reaches the light receiver. The light receiving level at the time is lower than the light receiving level A when the rolling path is normal. For this reason, the abnormality detection level B is set in consideration of the decrease. These light receiving levels A and B are set in a normal temperature state. The light receiving levels A and B are set by the light receiving level setting device 15.

After the completion of the rolling process in the rolling mill 1 (SP4 in FIG. 5), it is detected whether or not an unnecessary object is present in the rolling path 5 using an inspection device (SP5, SP6 in FIG. 5). The operation of the inspection device is as described above. When there is no unnecessary material in the rolling path 5, the light reception level at the laser beam receiver 13 is the normal light reception level A (FIG. 5, SP7). When there is an unnecessary object in the rolling path 5, the light receiving level at the laser beam receiver 13 is the abnormality detection level B (FIG. 5, SP8).

When the rolling is repeatedly performed, the surface temperature of the rolling roller increases because the workpiece is heated. When the surface temperature of the rolling roller rises, a change in the reflection state of the laser light passing through the rolling path 5 from the rolling roller and fluctuation of the laser light occur, and the laser light passes through the rolling path 5 as shown in FIG. The light receiving level of the laser light when it reaches the light receiver 13 passes through the rolling passage 5 at room temperature and passes through the laser light receiver.
It rises in comparison with the light receiving level of the laser beam when it reaches 13 (FIG. 5, SP9). Particularly in the case of hot working, the above tendency is large because the surface temperature of the rolling roller is high.

Here, when the light receiving level of the laser light received by the laser light receiver becomes higher than the initially set normal light receiving level A, this higher light receiving level is changed to a new normal light receiving level Aa.
And a new abnormality detection light receiving level Bb is set at a lower light receiving level than the new normal light receiving level Aa (FIG. 5, SP10).

The ratio of the abnormal detection light reception level Bb to the new normal light reception level Aa is set in advance, and is generally set to be the same as the ratio of the normal light reception level A and the abnormality detection light reception level B set initially.

Then, based on the newly set normal light reception level Aa and abnormality detection light reception level Bb, the light reception level of the laser light receiver 13 is determined to detect whether or not there is any unnecessary material in the rolling path 5.

This makes it possible to compensate for fluctuations in the state of reflection of the laser light from the rolling roller and increases in the light receiving level due to the fluctuation of the laser light, thereby enabling accurate detection.

Further, in this rolling path inspection apparatus, the laser light
Is provided close to the entrance 3 of the rolling path 5 in the rolling mill 1, so that the laser beam is received before the deformation or shading of the image of the laser beam received by the laser beam receiver 13 is enlarged. High detection can be performed. That is, when the surface temperature of the rolling roller rises, a reflection state of the laser beam passing through the rolling path 5 with the rolling roller and a fluctuation of the laser beam occur, and the laser beam reaching the laser beam receiver 13 emits a laser beam. The image of the laser beam irradiated from 11 may be deformed, and the brightness may become non-uniform, and a shading may occur. This phenomenon becomes more remarkable as the laser beam receiver 11 moves away from the entrance 3 of the rolling path 5. This is because, since a part of the laser beam 4 is reflected on the rolling roll, the contour of the image of the laser beam is maintained in the rolling passage 5, but when the laser beam 4 exits the rolling passage 5, the laser beam is opened. Because the laser light emitted from the laser light projector 11 is spread at a constant irradiation angle by the angle setting device 12, the laser light receiver 13 is moved away from the entrance and the laser light is expanded As a result, the brightness is reduced, and the deformation of the image and the difference in shading are enlarged. Therefore, the laser beam receiver 13 is connected to the entrance 3 of the rolling passage 5 in the rolling mill 1.
The laser beam is received before the laser beam is received by the laser beam receiver 13 and the laser beam is received before the deformation or shading in the image is enlarged. Rolling path 5 without being affected by fluctuation
Can accurately detect the presence of an unnecessary object.

[Effects of the Invention] As described above, according to the rolling path inspection method of the present invention, a laser beam is emitted from an exit side to an entrance side of a rolling path configured by arranging rolling rolls in multiple stages by a laser beam projector. When irradiating the light and detecting the unnecessary object existing in the rolling passage by receiving the laser light with the laser light receiver at the exit side of the rolling passage, the light receiving level of the laser light received by the laser light receiving device is initially When the received light level becomes higher than the set normal received light level, this higher received light level is set as a new normal received light level, and a new abnormal detected light level is set for this new received light level. Compensates for the effects of fluctuations in the laser light and changes in the reflection state on the received light level,
A highly accurate inspection can be performed.

Further, the rolling path inspection apparatus of the present invention is provided with a laser light receiving device that receives laser light emitted from a laser beam projector to a rolling path from an exit to an entrance, close to an entrance of the rolling path, thereby receiving a laser beam. The laser beam is received before the deformation or shading in the image of the laser beam received by the detector is enlarged, so that highly accurate detection can be performed.

Then, when the laser light receiver is separated from the optical axis of the laser light when rolling is performed in the rolling path, and is moved on the optical axis of the laser light when performing detection,
The laser beam receiver can be provided close to the entrance of the rolling passage without disturbing the movement of the workpiece during rolling.

Therefore, according to the present invention, it is possible to accurately detect the presence of an unnecessary object in the rolling passage without being affected by the temperature condition of the rolling passage, and it is possible to enhance the reliability of the inspection of the rolling passage.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 shows a schematic configuration of a rolling path inspection apparatus, and FIGS. 2 to 4 show a mechanism for providing a laser beam receiver. Figure, fifth
FIGS. 6 and 7 are flowcharts showing an operation when a rolling passage inspection is performed by using a rolling passage inspection device. FIGS. 6 and 7 are diagrams showing light receiving levels in a laser beam receiver. 1 ... rolling mill, 2 ... rolling stand, 3 ... entrance, 4 ...
… Exit, 5… Rolling path, 11… Laser beam projector, 12…
... Angle setting device, 13 ... Laser light receiver.

Claims (1)

(57) [Claims] 1. A laser beam irradiator irradiates a laser beam from a exit side to an entrance side of a rolling path constituted by arranging rolling rolls in multiple stages by a laser beam projector, and a laser beam receiver at the entrance side of the rolling path. In the method of receiving laser light and inspecting the state of the rolling path, setting a normal light receiving level at which the laser light irradiated from the laser light projector is received by the laser light receiver in a state where the rolling path is normal first. When the light receiving level of the laser light received by the laser light receiver becomes higher than the initially set normal light receiving level, the high light receiving level is set as a new normal light receiving level. Method.