JP2003279325A - Film thickness measuring method and device thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film thickness measuring method and measuring device capable of obtaining stable film thickness measurement value at a low cost. <P>SOLUTION: In the film thickness measuring method, the film thickness of a resin film 12 formed on the surface of a metal band 10 is measured by receiving reflection light of infrared cast on the metal band 10 surface and operating the absorption amount of the reflection light by a resin film 12. According to whether or not plate leaping directions are the same for a continuous plating line as a pre-processing for producing a metal band 10 and for resin coating line as a self processing, the directions of casting light and receiving light are switched. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film thickness measuring method and a film thickness measuring device for measuring the film thickness of a resin film in a manufacturing process for forming a resin film on a metal strip, and more particularly to a stable film thickness measuring method. It is related to effective techniques for obtaining values.

[0002]

2. Description of the Related Art Conventionally, a surface-treated steel sheet having improved decorativeness and corrosion resistance has been proposed by forming a resin film or the like on the surface of the steel sheet. Here, the adhesion amount of the resin film directly affects the decorativeness, corrosion resistance, or workability of the surface-treated steel sheet, so in the resin film formation step, the film thickness of the resin film is measured and kept within a certain range. Need to hold.

As a method for measuring the film thickness of this resin film, for example, online measurement using a film thickness meter utilizing an infrared reflection method is known. According to this infrared reflection method, the film thickness can be measured by projecting infrared rays from the resin film side onto the surface of the surface-treated steel sheet and measuring the reflection spectrum thereof. For example, in a surface-treated plated steel sheet in which a resin film is formed on the surface of a plated steel sheet, first, in a continuous plating line such as a continuous hot dip galvanizing line or a continuous electroplating line, galvanizing or other plating is performed on the surface of the steel strip. It is applied, temper-rolled, and then wound.

Then, after the resin film is formed on the surface of the steel strip in the resin film forming line, the film of the resin film is detected by a detector installed in a certain direction with respect to the passing direction of the steel strip. Thickness measurement is done online. Here, in the operation in the resin film forming line, since the steel strip wound after the temper rolling is unwound to pass the steel strip, the passing direction of the steel strip in the resin film forming line is: The strip running direction of the steel strip in the continuous plating line is usually the opposite direction.

[0005]

However, when there is a defective portion in the rolled steel strip which has been processed in the continuous plating line, it is necessary to remove the defective portion before the processing in the resin film forming line. The steel strip is rewound on the coiling line and the defective portion is cut off. If this recoiling line is passed an odd number of times, the strip running direction of the steel strip in the resin film forming line may be the same as the normal direction opposite to the strip running direction of the steel strip in the continuous plating line.

In this case, there is a problem that the measured value of the film thickness of the resin film shows an abnormal value with respect to the actual adhesion amount.
This is a continuous plating line, which is a pre-process of the resin film formation line that measures the film thickness of the resin film, because a directional surface shape is formed on the steel strip surface during the temper rolling process. Steel strip running direction in
This is considered to be because if the direction of passing the steel strip in the resin film forming line is the same direction, an abnormality will occur in the infrared reflection state.

In order to solve such a problem, it is opposite to the case where the strip running direction of the steel strip in the resin film forming line is the same as the strip running direction of the steel strip in the continuous plating line which is the previous step. In some cases, it is possible to create two types of calibration curves and use the calibration curves properly. However, there is no guarantee that the degree of influence will always be the same, and it was practically difficult to realize.

As a film thickness measuring method which is not affected by the surface of the steel strip, a metal in the film thickness is used as a target and fluorescent X
A method of measuring with a line is also included. However, the film thickness measurement method using fluorescent X-rays has a disadvantage that the cost increases as compared with the film thickness measurement method using the infrared reflection method. The present invention has been made in view of the above circumstances, and a pre-process such as a continuous plating line for forming a directional surface shape on the surface of a metal strip, and a resin film forming line for measuring the film thickness of a resin film. Film thickness measurement method and film thickness that can obtain stable film thickness measurement values at low cost even if the metal strip passing direction in the same process as in the same process or in the opposite direction An object is to provide a measuring device.

[0009]

In order to solve such a problem, the film thickness measuring method according to the present invention is such that the film thickness of a resin film formed on the surface of a metal strip is projected onto the surface of the metal strip. Receiving reflected light of infrared light that is illuminated, a film thickness measuring method for measuring by calculating the absorption amount of the reflected light by the resin film, based on the previous process passage history of manufacturing the metal strip, It is characterized in that the directions of the light projection and the light reception are switched.

According to the film thickness measuring method of the present invention, the direction of light projection and light reception is switched on the basis of the history of the previous process of manufacturing the metal strip, so that the surface of the metal strip has directionality. The strip running direction of the metal strip in the previous step of forming the surface shape and the strip running direction of the metal strip in the self-step of measuring the resin film are the same direction or even in the opposite direction, It becomes possible to always make the infrared ray projecting direction and the infrared ray receiving direction with respect to the surface of the metal band constant with respect to the sheet passing direction in the previous step of forming a directional surface shape. For this reason, abnormal reflection of infrared rays due to the surface shape of the metal band does not occur, and a stable film thickness measurement value can be obtained at low cost.

The first film thickness measuring device according to the present invention receives the infrared ray reflected from the surface of the metal strip and the light projector which projects the infrared ray onto the surface of the metal strip on which the resin film is formed. A film thickness measuring device comprising a detector comprising a light receiver, and detector rotating means for rotating the detector so that the positions of the light projector and the light receiver with respect to the passage direction of the metal plate are switched, Light emitting / receiving position determining means for transmitting a rotation signal to the detector rotating means on the basis of a history of previous processes for manufacturing the metal strip.

According to the first film thickness measuring device of the present invention, the film thickness measuring method of the present invention can be easily realized. The second film thickness measuring device in the present invention, a projector for projecting infrared light on the surface of the metal band on which the resin coating is formed, and a light receiver for receiving the reflected light of the infrared light reflected from the surface of the metal band. A film thickness measuring apparatus comprising a detector comprising: a first light emitting device, wherein the light projector is arranged upstream in a passage direction of the metal strip, and the light receiver is arranged downstream in a passage direction of the metal strip. And a second detector in which the light emitter is arranged on the downstream side in the passage direction of the metal band and the light receiver is arranged on the upstream side in the passage direction of the metal band, and the first detection Switching means for selecting one of the detector and the second detector, and detector position determination for transmitting a switching signal to the detector switching means based on a history of previous steps of manufacturing the metal strip. Means and It is characterized by having a.

According to the second film thickness measuring device of the present invention, the film thickness measuring method of the present invention can be easily realized.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is an explanatory view showing a first embodiment of the film thickness measuring apparatus of the present invention. 2A and 2B show a detector in the film thickness measuring device of the present invention, wherein FIG. 2A is a plan view and FIG. 2B is a front sectional view.

The film thickness measuring device is used in a resin film forming (resin coating) line in a metal band manufacturing process.
A device for measuring the film thickness of a resin film formed on the surface of a metal band, which is installed on the downstream side of a resin coating line. As shown in FIG. 1, the film thickness measuring device 100 includes a detector 20 including a light projector 21 for projecting infrared rays onto the surface of the metal strip 10 and a light receiver 22 for receiving reflected light of infrared rays by the light projector 21. From the host computer 50, a detector rotation device 30 that rotates the detector 20 to change the positions of the light projector 21 and the light receiver 22 with respect to the sheet passing direction (passing direction, right direction in FIG. 1) of the metal strip 10. The light emitting and receiving device for transmitting a rotation signal to the detector rotating device 30 based on the transmitted information indicating whether the metal strips 10 pass through the same direction in the resin coating line and in the preceding continuous plating line. And a position determining device 40.

As shown in FIG. 2, the detector 20 has a structure in which a light projector 21 and a light receiver 22 are provided at positions facing each other in the sheet passing direction of the metal strip 10. When the detector rotating device 30 receives the rotation signal from the light emitting / receiving position determining device 40, the detector rotating device 30 detects the rotation signal based on the rotation signal so as to change the positions of the light projector 21 and the light receiver 22 with respect to the sheet passing direction of the metal strip 10. Place the container 20 against the passing direction of the metal strip 10.
It is designed to rotate 0 °.

The light projecting / receiving position determining device 40 includes a metal strip 10 in a resin coating line, which is a self-process, and a plate passing direction of the metal strip 10 in a continuous plating line which is a pre-process.
A detection signal indicating whether the sheet passing direction is the same direction or the opposite direction is received from the host computer 50. Further, the light emitting / receiving position determining device 40 is configured to receive from the tracking processing device 60 a detection signal indicating whether or not the welding point of the metal strip 10 has passed the Xm front point of the film thickness measuring device 100. The tracking processing device 60 detects a welding point on the metal strip 10 by a welding point detector (WPD: Weld Point Director) 61, and measures the length by a pulse generator 62, thereby performing the tracking processing of the welding point. . Then, the light emitting / receiving position determining device 40 uses the host computer 5
0 and a detection signal transmitted from the tracking processing device 60, a rotation signal is transmitted to the detector rotation device 30.

Here, since the film thickness measurement value when the detector 20 is rotating cannot be guaranteed, X of the film thickness measuring device 100 is not guaranteed.
The m front point is determined based on the cut-off length of the front coil at the welding point. The operating end for rotating the detector 20 is determined from the line speed and the total cut-off length of the front and rear coils of the welding point. Next, an operation example of the film thickness measuring method by the film thickness measuring apparatus 100 having the above configuration will be described with reference to the drawings. FIG. 3 is a flowchart showing an operation example of the film thickness measuring method of the present invention.

In the following description, with respect to the position of the detector, "0" when the resin coating line and the continuous plating line pass through the metal strip 10 in opposite directions.
"Position", "180 ° position" when they are in the same direction
In this case, the “position at 0 °” and the “position at 180 °” have a positional relationship in which the light projector 21 and the light receiver 22 are switched with respect to the sheet passing direction of the metal strip 10. Means that. That is, at the “0 ° position”,
Infrared light is projected from the upstream side of the metal strip 10 in the sheet passing direction, and infrared reflected light reflected from the surface of the metal strip 10 is received on the downstream side. Then, at the “180 ° position”, infrared rays are projected from the downstream side of the metal strip 10 in the sheet passing direction,
The infrared reflected light reflected from the surface of the metal strip 10 is received on the upstream side.

First, the metal strip 1 is processed through a continuous plating line which is a pre-process and a resin coating line which is a self-process.
0 When the metal strip 10 having the plating 11 and the resin film 12 formed on the surface is transported to the downstream of the resin coating line, the host computer 50 that manages the entire manufacturing process of the surface-treated metal strip will be connected to the resin coating line. A determination is made as to whether or not the passing directions of the metal strip 10 in the continuous plating line are the same (S100).

At this time, if the determination in S100 is "YES", that is, the metal strip 1 that has passed through the continuous plating line.
When 0 passes through the recoiling line an odd number of times and then is conveyed to the resin coating line, when the resin coating line and the continuous plating line pass through the metal strip 10 in the same direction, In the tracking processing device 60, it is determined whether or not the welding point of the metal strip 10 has passed the Xm front point of the film thickness measuring device 100 (S101).

Next, if the determination in S101 is "YES", it is determined whether or not the current detector position is 180 ° (S102). Is transmitted from the light emitting / receiving position determining device 40 to the detector rotating device 30, and the detector 20 moves 180 °.
The light receiver 22 is arranged on the upstream side and the light projector 21 is arranged on the downstream side of the metal strip 10 in the sheet passing direction (S103).

Using this detector 20, infrared rays are projected from the downstream side of the metal strip 10 in the sheet passing direction, and infrared reflected light reflected from the surface of the metal strip 10 is passed through the metal strip 10. By receiving light on the upstream side in the direction, the film thickness of the resin film 12 formed on the surface of the metal strip 10 is measured (S107). On the other hand, the determination in S100 is "N
If it is “O”, that is, the metal strip 10 that has passed through the continuous plating line is conveyed to the resin coating line as it is or after passing the recoiling line an even number of times, so that the resin coating line and the continuous plating line are separated. When the passing direction of the metal strip 10 is in the opposite direction, subsequently, in the tracking processing device 60, it is determined whether the welding point of the metal strip 10 has passed the Xm front point of the film thickness measuring device 100. Is performed (S104).

Next, if the determination in S104 is "YES", it is determined whether or not the current detector position is 0 ° (S105). Is transmitted from the light emitting / receiving position determining device 40 to the detector rotating device 30, the detector 20 is rotated to a position of 0 °, and the light emitting device 2 is provided on the upstream side in the sheet passing direction of the metal strip 10.
1, the light receiver 22 is arranged on the downstream side (S106).

Using this detector 20, infrared rays are projected from the upstream side of the metal strip 10 in the strip passing direction, and infrared reflected light reflected from the surface of the metal strip 10 is passed through the metal strip 10. By receiving light on the downstream side in the direction, the film thickness of the resin film 12 formed on the surface of the metal strip 10 is measured (S107). As described above, according to the film thickness measuring method in the present embodiment, the passage direction of the metal strip 10 in the resin coating line provided with the film thickness measuring device 100 for the resin film 12 and the continuous plating line which is the preceding step thereof. By making it possible to change the arrangement of the light projector 21 and the light receiver 22 constituting the detector 20, based on a detection signal indicating whether the sheet passing direction of the metal strip 10 is the same, the previous process and the own process can be performed. Whether the plate passing direction is the same or opposite, light should always be projected and received from a fixed direction with respect to the directionality of the surface of the metal strip 10 formed in the continuous plating line in the previous step. Is possible. Therefore, a stable film thickness measurement value can be obtained at low cost.

The detector rotating device 30 in this embodiment corresponds to the detector rotating means in the claims, and similarly, the light emitting and receiving position determining device 40 corresponds to the light emitting and receiving position determining means. . (Second Embodiment) FIG. 4 is an explanatory view showing a second embodiment of the film thickness measuring apparatus of the present invention.

The film thickness measuring apparatus 100A in this embodiment
Is the metal strip 1 as the detector 20 in the first embodiment.
The projector 21 is provided on the upstream side with respect to the sheet passing direction of 0,
First detector 20A provided with a light receiver 22 on the downstream side
And the optical receiver 22 on the upstream side with respect to the passing direction of the metal strip 10.
And a second detector 20B provided with a projector 21 on the downstream side, and the first detector 20A and the second detector 20B are installed in parallel on the upper surface of the metal strip 10. ing. In addition, a detector switching device 30A that selects one of the first detector 20A and the second detector 20B,
Detector position that sends a switching signal toward the detector switching device 30A based on the information transmitted from the upper-level computer 50 whether the resin coating line and the metal strip 10 in the preceding process have the same sheet passing direction. Determination device 40A
And are equipped with.

When the detector switching device 30A receives the detection signal from the detector position determining device 40A, the detector switching device 30A, based on the information, detects the first detector 20A or the second detector 20B.
Either one of them is selected and activated. In the detector position determining device 40A, the passing direction of the metal strip 10 in the continuous plating line, which is the previous process, and the passing direction of the metal strip 10 in the resin coating line, which is the own process, are the same direction or opposite directions. A detection signal indicating whether or not there is is received from the host computer 50.
Further, the detector position determining device 40A is adapted to receive from the tracking processing device 60 a detection signal indicating whether or not the welding point of the metal band 10 has passed the Xm front point of the film thickness measuring device 100. This tracking processing device 6
In No. 0, the welding point on the metal strip 10 is detected by the welding point detector 61, and the length is measured by the pulse generator 62 to perform the tracking processing of the welding point. Then, the detector position determining device 40A transmits a switching signal to the detector switching device 30A based on the detection signal transmitted from the host computer 50 and the tracking processing device 60.

Next, a film thickness measuring method using the film thickness measuring apparatus 100A having the above structure will be described with reference to the drawings.
FIG. 5 is a flowchart showing an operation example of the film thickness measuring method of the present invention. First, a metal strip 10 having a plating 11 and a resin film 12 formed on its surface is passed through a continuous plating line which is a pre-process and a resin coating line which is a self-process.
However, when transported to the downstream of the resin coating line, in the host computer 50 that manages the entire manufacturing process of the surface-treated metal strip, the resin coating line and the continuous plating line have the same passing direction of the metal strip 10. Whether or not it is determined (S200).

At this time, if the determination in S200 is "YES", that is, the metal strip 1 that has passed through the continuous plating line.
When 0 passes through the recoiling line an odd number of times and then is conveyed to the resin coating line, when the resin coating line and the continuous plating line pass through the metal strip 10 in the same direction, In the tracking processing device 60, it is determined whether or not the welding point of the metal strip 10 has passed the Xm front point of the film thickness measuring device 100A (S201).

Next, if the determination in S201 is "YES", a switching signal is transmitted from the detector position determining device 40A to the detector switching device 30A, and the upstream side of the metal strip 10 in the sheet passing direction. Then, the light receiver 22 selects the second detector 20B having the light projector 21 arranged on the downstream side and activates only the second detector 30B (S202).

Then, by using the second detector 30B, infrared rays are projected from the downstream side (right side in FIG. 4) of the metal strip 10 in the sheet passing direction and are reflected from the surface of the metal strip 10. By receiving light on the upstream side (left side in FIG. 4) of the metal strip 10 in the sheet passing direction,
The film thickness of the resin film 12 formed on the surface of the metal strip 10 is measured (S205).

On the other hand, when the determination in S200 is "NO", that is, the metal strip 10 that has passed through the continuous plating line is conveyed to the resin coating line as it is or after passing through the recoiling line an even number of times. , Metal strip 10 between resin coating line and continuous plating line
When the sheet passing direction of the film is in the opposite direction, the tracking processing device 60 subsequently causes the X of the film thickness measuring device 100 to be changed.
It is determined whether or not the welding point of the metal strip 10 has passed the m front point (S203).

Next, when the determination in S203 is "YES", a switching signal is transmitted from the detector position determining device 40A to the detector switching device 30A, and the upstream side of the metal strip 10 in the sheet passing direction. Then, the light projector 21 selects the first detector 20A having the light receiver 22 arranged on the downstream side and activates only the first detector 20A (S204).

Then, by using the first detector 20A, infrared rays are projected from the upstream side in the sheet passing direction of the metal strip 10 and infrared reflected light reflected from the surface of the metal strip is passed through the metal strip. By receiving light on the downstream side in the direction, the film thickness of the resin film 12 formed on the surface of the metal strip 10 is measured (S205). As described above, according to the film thickness measuring method of the present embodiment, the passing direction of the metal strip 10 in the resin coating line provided with the film thickness measuring device 100 for the resin film 12 and the continuous plating line which is the preceding process thereof. Based on a detection signal indicating whether or not the metal strip 10 is in the strip passing direction, the projector 21 is set in the strip passing direction based on the detection signal.
And first detector 20 with different arrangement of light receiver 22
By switching A and the second detector 20B, it is possible to form in the continuous plating line, which is the previous process, even if the passing directions of the previous process and the own process are the same or opposite. With respect to the directionality of the surface of the metal strip 10 that is present, it is possible to always project and receive light from a fixed direction. Therefore, a stable film thickness measurement value can be obtained at low cost.

Here, in the present embodiment, the first detector 20A and the second detector 20B are installed in parallel on the upper surface of the metal strip 10 so that only one of the selected ones is activated. However, the present invention is not limited to this, as long as only one of the selected ones projects infrared rays onto the upper surface of the metal strip 10 and receives infrared absorption light. For example, either one of the first detector 20A and the second detector 20B selected may be set so as to advance to the upper surface of the metal strip 10 and operate.

The detector switching device 30A in this embodiment corresponds to the detector switching means in the claims, and similarly, the detector position determining device 40A corresponds to the detector position determining means. . Here, in the first and second embodiments, when the plate passing direction of the metal strip 10 in the continuous plating line and the resin coating line is opposite, light is projected from the upstream side in the plate passing direction in the resin coating line. However, based on the directionality formed on the surface of the metal strip 10 in the continuous plating line which is the previous step,
As long as the film thickness can be measured in a state where there is no abnormality in infrared absorption, the positions of the projector 21 and the light receiver 22 are not limited to this.

[0038]

As described above, according to the film thickness measuring method of the present invention, the passage direction of the metal strip in the preceding step of forming a directional surface shape on the surface of the metal strip and the resin film Whether the direction of passage of the metal strip in the process of measuring the film thickness is the same direction or the opposite direction, it is possible to always keep the infrared light projecting direction and the light receiving direction on the metal band surface constant. Since it becomes possible, a stable film thickness measurement value can be obtained at low cost.

According to the film thickness measuring device of the present invention, the film thickness measuring method of the present invention can be easily realized.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration example of a film thickness measuring device of the present invention.

FIG. 2 shows a detector of the film thickness measuring device of the present invention,
(A) is a plan view and (b) is a front sectional view.

FIG. 3 is a flowchart showing an operation example of the film thickness measuring method of the present invention.

FIG. 4 is an explanatory diagram showing another configuration example of the film thickness measuring device of the present invention.

FIG. 5 is a flowchart showing an operation example of the film thickness measuring method of the present invention.

[Explanation of symbols]

10 Metal Band 11 Plating 12 Resin Film 20 Detector 20A First Detector 20B Second Detector 21 Projector 22 Light Receiver 30 Detector Rotating Device (Detector Rotating Means) 30A Detector Switching Device (Detector Switching Means) 40 light emitting / receiving position determining device (light emitting / receiving position determining means) 40A detector position determining device (detector position determining means) 50 upper computer 60 tracking processing device 61 welding point detector 62 pulse generator 100, 100A film thickness measuring device

Claims (3)

[Claims] 1. A film thickness of a resin film formed on a surface of a metal band is received by reflected light of infrared rays projected on the surface of the metal band, and an absorption amount of the reflected light by the resin film is calculated. The film thickness measuring method according to claim 1, wherein the light projecting direction and the light receiving direction are switched based on a history of previous steps of manufacturing the metal strip. 2. A detector comprising a light projector for projecting infrared rays on the surface of the metal band on which the resin film is formed, and a light receiver for receiving the reflected light of the infrared rays reflected from the surface of the metal band. A film thickness measuring device, wherein a detector rotating unit that rotates the detector so that the positions of the light emitter and the light receiver with respect to the passing direction of the metal strip are switched, and a history of previous steps for manufacturing the metal strip. And a light emitting / receiving position determining means for transmitting a rotation signal to the detector rotating means based on the above. 3. A detector comprising a light projector for projecting infrared rays on the surface of the metal band on which the resin film is formed and a light receiver for receiving the reflected light of the infrared rays reflected from the surface of the metal band. A film thickness measuring device, wherein the light projector is arranged upstream in the passage direction of the metal band, and the light receiver is arranged downstream in the passage direction of the metal band; and the light projector. Is disposed on the downstream side in the passage direction of the metal strip, and the photodetector is disposed on the upstream side in the passage direction of the metal strip, and the first detector or the second detection A detector switching means for selecting any one of the detectors, and a detector position determining means for transmitting a switching signal to the detector switching means based on a previous process passage history of manufacturing the metal strip, Characteristic The film thickness measuring device for.