JPH0125005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a radiation thickness measuring device that accurately measures the thickness of the edge of a steel plate and performs optimal rolling control.

[Technical background of the invention and its problems]

Generally, many rolled steel plates have a crown shape as shown in FIG. Conventionally, when making such a crown-shaped rolled steel plate 1, there are two methods: one is to measure the thickness of the central part of the steel plate, and the other is to measure the thickness of the edge of the steel plate. The former means, as shown in FIG. 1, has a radiation source 3 and a radiation detector 4 disposed facing each other at both the upper and lower ends of the C frame 2 so as to sandwich the central portion of the steel plate that is being conveyed in a direction perpendicular to the plane of the paper. , the thickness CH at the center of the steel plate is measured by the thickness detection section consisting of the radiation source 3 and the radiation detector 4, and this plate thickness signal is fed back to the rolling mill to produce the rolled steel plate 1 of the required thickness. It's on. However, the nominal thickness of the rolled steel plate 1 is determined by the thickness of the edge of the plate, so in order to avoid making the edge of the plate thin, a steel plate that is equal to the steel plate to be rolled is prepared in advance. At the same time, the thickness of the central part of the steel plate is measured by adding the thickness obtained from the crown shape to this thickness to obtain the set value of the central part thickness. The thickness of the center part of the steel plate to be rolled is determined based on the measured thickness of the center part of the steel plate being conveyed, and then the thickness of the edge part of the plate is predicted from the crown shape and rolled by a rolling mill. Rolled steel plate 1 with a nominal thickness that satisfies
is creating. However, with this method, a certain thickness is added to the thickness of the central portion, so there is a drawback that material corresponding to the added thickness is always wasted.

In this regard, the latter method described above measures the thickness of the plate at the edge of the plate using a thickness detecting section consisting of a radiation source 3 and a radiation detector 4 as shown in Fig. 2, and provides feedback to the rolling control system. A rolled steel plate 1 with less waste can be produced. However, when such a thickness measuring means is used, the following problems occur. In other words, when the notch 5 exists at the end of the steel plate 1 as shown in FIG. 3, the radiation detector 4 directly receives the radiation dose from the radiation source 3 on the plate thickness measurement line L1. There is a drawback that the output of the radiation detector 4 cannot be directly used as a rolling control signal because the output exceeds the measurement range.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and even if there is a notch at the end of the width direction of the object to be measured, the thickness signal at the end of the board is detected by the thickness detection unit without being affected by the notch. An object of the present invention is to provide a radiation thickness measuring device that can use the following as a signal for rolling control.

[Summary of the invention]

That is, in the present invention, a notch detection section for detecting a notch in the widthwise end of the object to be measured is provided in addition to the thickness detection section, and the notch can be quickly detected by this notch detection section. A radiation thickness measurement device used for rolling control, etc., configured to hold and output a plate thickness signal from a thickness detection unit and release the holding of the plate thickness signal after the notch of the object to be measured passes. It is a device.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to FIGS. 4 to 6. Furthermore, Fig. 4 shows the arrangement of the thickness detection part and the plate edge detection part which acts as the notch detection part, and Fig. 5 shows the measurement line of the object to be measured in the thickness detection part and the plate edge detection part. FIG. 6 is a diagram showing the configuration of the entire device. That is, this apparatus includes a detection system 20 that detects the width direction end portion of the object to be measured 10 according to its purpose, and a signal processing system 30 that processes the signal output from this detection system 20. As shown in FIG. 4, in this detection system 20, a radiation source 22 and a light source 23 are arranged, for example, at a distance L ₂ from the end side of the lower frame portion 21a of the C frame 21 toward the body side. C frame 2
A radiation source 22 and a light source 2 are installed in the upper frame portion 21b of 1.
A radiation detector 24, such as an ionization chamber, for detecting the radiation dose, and a plate end detection section 25, for detecting the presence or absence of the end of the object to be measured 10 from the presence or absence of light, are respectively disposed corresponding to the radiation dose. This plate edge detection section 25 has a plurality of photo sensors, for example, in the width direction of the edge of the object to be measured 10.
Use a linear array sensor with diodes arranged. Note that the thickness detection section includes a radiation source 22 and a radiation detector 24, and the board edge detection section includes a light source 23 and a board edge detection section 25.

Therefore, if the thickness detection section and the plate edge detection section are arranged as described above, and the element at a certain position of the linear array sensor constituting the plate edge detection section 25 is specified (determination level described later), the fifth As shown in the figure, the thickness detection unit can measure the thickness of the plate on the plate thickness measurement line L1, and the plate edge detection unit can measure the plate thickness on the plate edge presence/absence measurement line L3.
It becomes possible to detect the presence or absence of a board edge at the top. Therefore, when the notch 11 exists at the edge of the plate of the object to be measured 10, the thickness detection unit will reach point b after the plate edge detection unit detects point a. . The arrival times for points c and d are completely opposite to those described above.

Next, the signal processing system 30 generates a plate thickness signal based on the deviation between the plate thickness detection signal detected by the radiation detector 24 and the plate thickness setting signal corresponding to the predetermined plate edge thickness measurement line L1. Signal processing unit 31 to output
, a storage output unit 32 that stores and outputs the plate thickness signal from the signal processing unit 31, a setting circuit 33 that sets a determination level corresponding to the size (depth) of the notch 11, and a plate edge detection circuit. A comparator circuit that provides a memory retention signal to the memory output unit 32 when the output level from the unit 25 exceeds the determination level, and provides a signal to release the memory retention to the memory output unit 32 when the output level falls below the determination level. It is equipped with 34. 35
is an alarm section which has a function of outputting an alarm signal AL if the memory retention is not released within a predetermined time after receiving the memory retention signal from the comparator circuit 34.

Next, the operation of the radiation thickness measuring device configured as described above will be explained. First, a plate thickness setting level corresponding to the plate thickness measurement line L1 at the plate end is set in the signal processing section 31, and a determination level corresponding to the size of the notch 11 is set in the setting circuit 33. In this state, if the object to be measured 10 is transported in the positional relationship as shown in FIGS. The emitted radiation passes through the object to be measured 10 and enters the radiation detector 24 . The radiation detector 24 converts the incident radiation dose into an electrical signal and sends it to the signal processing section 31.
This signal processing section 31 compares the signal from the radiation detector 24 with a predetermined plate thickness setting signal, and outputs a signal _S1 according to the deviation as shown in FIG. This signal S ₁ is outputted to the outside via the storage output section 32 as a plate thickness signal S ₃ . At this time, the linear array sensor of the plate edge detector 25 is sequentially scanned by the signal processing unit 31 or another scanning circuit (not shown), but if the notch 11 does not exist in the object to be measured 10 , a low level signal S ₂ a shown in FIG. 7 S ₂ is output from the linear array sensor of the plate edge detector 25.
is output.

Subsequently, the object to be measured 10 is transported, and the detection system 20
When the notch 11 of the object to be measured 10 reaches , the plate edge detector 25 outputs an output signal S ₂ b that matches the shape of the notch 11 as shown in FIG. 7 S ₂ . The comparator circuit 34 receiving this signal S ₂ b compares it with the judgment level V _L of the setting circuit 33 and determines the level.
A signal is sent to the storage output unit 32 to hold the output S ₁ a of the radiation detector 24 at the point exceeding V _L , that is, at point a. As a result, the storage output unit 32 holds the signal S 3 b shown in FIG _. 7 S ₃ which is the signal at point a, and outputs the held signal S ₃ b. Furthermore, when the object to be measured 10 is transported, the radiation from the radiation source 22 enters the radiation detector 24 as it is without being attenuated at the time point b has passed. For this reason, the radiation detector 24 outputs _{the signal S 1 b} shown in FIG. Since the deviation signal is held and outputted, a signal such as _S3b ' shown in FIG. 7, _S3 , which is affected by the notch 11, for example, is not outputted.

Further, when the object to be measured 10 is transported, the radiation detector 24 detects the passage of point c and detects the thickness of the plate without a notch, and then the plate edge detector 25
The signal at point d falls and exceeds the judgment level V _L ,
It is detected by the comparison circuit 34, and the signal is sent to the memory output section 32 as a signal for canceling memory retention.
As a result, from the storage output unit 32, the measured object 10
Even if there is a notch 11 in the object, a signal S ₃ b that approximates the thickness of the object to be measured 10 is continuously output without outputting a signal S ₃ b' with an extreme level change. be able to.

Also, due to the difference in depth of the notch 11 of the object to be measured 10, the notch 11 is located at the plate edge presence/absence measurement line L.
3, but may not pass through the plate thickness measurement line L1. In this case, the radiation detector 24 outputs a _plate thickness detection signal as shown in FIG. A signal like ₂ is output. Therefore, the comparison circuit 34 outputs the sensor output S ₂ and the setting circuit 33.
, _and a signal for memory retention is provided to the memory output section 32. Therefore, the signal S 3 b shown in FIG. 8 S ₃ is output from the memory output section 32, but it is not much different from the signal S _{3 b} ' when no memory is retained, and there is no problem in rolling control. .

In the above embodiment, the plate end detection part was provided integrally with the plate thickness detection part on the C frame 21, but from the viewpoint of reducing the installation location and the size of the detection system main body, for example, an appropriate member other than the C frame 21 or It may be set up at a location. Moreover, the radiation source 22 and the light source 23 may be attached to the upper frame part 21b, and the radiation detector 24 and the plate edge detector 25 may be attached to the lower frame part 21a. Furthermore, the plate edge detection unit is separated by two parts on the upstream and downstream sides of the plate thickness detection unit.
By providing one, the purpose of the present apparatus can be reliably achieved even if the operating characteristics of the signal processing system 30 are extremely slow. Alternatively, a delay circuit may be provided in the memory output section 32 to release the memory retention after a predetermined time delay from the falling point of the output of the comparison circuit 34. In addition, without fixing the plate thickness measurement line L1 at the plate end, C
It is also possible to adopt a configuration in which the frame 21 and the like are equipped with a drive device to move the C frame 21 and the like in the width direction of the object to be measured 10 in accordance with the output of the plate edge detector 25. In this way, for example, when there is a gradual notch change, the plate thickness can always be measured at a constant distance from the plate edge, and only when there is a steep notch change, the thickness can be measured by the signal processing of this device. It can be solved.
In addition, the present invention can be modified and implemented in various ways without departing from the gist thereof.

〔Effect of the invention〕

As described in detail above, according to the present invention, a plate edge detection unit is provided further toward the widthwise end side of the measured part than the thickness detection unit that detects the edge plate thickness of the measured object, and this plate edge detection part The output of the thickness detection unit is held and output immediately after detecting that there is no plate edge, and the holding state is released when a plate edge is detected, so that a notch exists at the widthwise edge of the object to be measured. Therefore, it is possible to provide a radiation thickness measuring device that can reliably obtain a signal that can be used for rolling control without being affected by the above.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional device, FIGS. 2 and 3 are diagrams showing other examples of the conventional device, and FIGS. 4 to 6 are examples of a radiation thickness measuring device according to the present invention. Figure 4 is a front view showing the plate thickness and plate edge detection system, Figure 5 is a top view explaining the measurement line by the detection system, and Figure 6 is the overall configuration of the device. 7 and 8 are time charts for explaining the operation of the apparatus of the present invention, respectively. 10...Object to be measured, 11...Notch, 20...
...Detection system, 22...Radiation source, 23...Light source, 2
4... Radiation detector, 25... Board edge detector, 30
... Signal processing system, 31 ... Signal processing section, 32 ...
Memory output section, 33...setting circuit, 34...comparison circuit.

Claims (1)

[Scope of Claims] 1. A radiation generator and a radiation detector are disposed facing each other, and the plate thickness at the widthwise end of the object to be measured, which is conveyed in the longitudinal direction, is detected between the radiation generator and the radiation detector. a notch for detecting the presence or absence of a notch in the object to be measured at a position closer to the widthwise end of the object than the thickness detection position of the thickness detection section in the object to be measured; a detection section;
When a notch presence signal is received from the notch detection section, the current signal from the radiation detector is held and this signal is output, and when a notch presence signal is received from the notch detection section. A radiation thickness measuring device comprising: a storage output section that sometimes releases a signal from the radiation detector. 2. The radiation thickness according to claim 1, wherein the notch detection section is configured to supply a signal indicating the presence or absence of a notch at the widthwise end of the object to be measured to the storage output section based on the discrimination level. measuring device. 3. The radiation thickness measuring device according to claim 1, wherein the notch detection section is integrated with the thickness detection section. 4. The radiation thickness measuring device according to claim 1, wherein the notch detection section is configured separately from the thickness detection section. 5. The radiation thickness measuring device according to claim 1, wherein the notch detection section is disposed on the upstream side and the downstream side of the thickness detection section in the object conveyance direction, respectively. 6. The memory output section has a delay function for delaying the release time for a certain period of time when the holding signal of the radiation detector is released in response to the signal indicating the absence of the notch at the edge of the object in the width direction of the notch detection part. A radiation thickness measuring device according to claim 1, comprising a circuit.