JPH1151634A - Plate thickness measurement method and apparatus - Google Patents

Abstract

(57) [Problem] To provide a device for measuring the thickness of a plate by moving a detector for measuring the thickness of the plate to accurately measure the thickness of the plate without trouble. According to the present invention, prior to a thickness measurement, calibration data of a traveling rail (20, 40) with respect to a predetermined reference plane (66) is acquired in advance in accordance with a traveling position of a distance sensor (14, 16). The actual measurement data of the hydraulic plate-like body 12 is corrected based on the above, and the plate thickness is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the thickness of a plate, and more particularly, to a method of moving a distance sensor along a running rail disposed substantially parallel to the plate. The present invention relates to a method and an apparatus for measuring the thickness of a plate-like body by measuring the distance to the sheet thickness.

[0002]

2. Description of the Related Art When measuring the thickness of a plate-like body such as a board for building materials, there are usually a method of pressing the plate-like body against a flat base such as a surface plate and measuring from one side with a distance sensor; There is a method of sandwiching a plate-like body from above and below with a distance sensor, measuring the distance to the plate-like body with each distance sensor, and calculating the plate thickness based on the distance.

In any of the measuring methods, when the distance sensor is fixed and the plate-shaped body is traveled to perform the measurement, a large error does not occur in the measurement dimension. When the measurement is performed while traveling along the travel rail, the accuracy of the distance between the distance sensors or the distance between the distance sensor and the surface plate at each position of the traveling rail is directly reflected in the measurement accuracy.

Therefore, conventionally, the accuracy of measurement has been improved by increasing the processing accuracy and assembly accuracy of the traveling rail.

[0005]

However, in the above-described conventional plate thickness measuring device, the processing accuracy and assembly accuracy of the running rail are increased, so that the manufacturing cost is increased, and the driving section and the like are required for repair or the like. Disassembly of the running rail has the disadvantage that it takes a lot of time to adjust the accuracy during assembly.

The present invention has been made in view of such circumstances, and provides a method and an apparatus for measuring the thickness of a plate-like body, which can accurately measure the thickness of the plate-like body without trouble. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a method for driving a plate-like body thickness measuring detector along a traveling system path substantially parallel to the plate-like body. Then, by measuring the distance to the plate-like body, in the plate-like body thickness measuring method for measuring the thickness of the plate-like body, the calibration data of the traveling path with respect to a predetermined reference plane of the detector It is characterized in that it is acquired in advance in accordance with the traveling position, and the actual measurement data of the plate-like body is corrected based on the calibration data.

According to the present invention, prior to the measurement of the sheet thickness, calibration data of a traveling route with respect to a predetermined reference plane is acquired in advance in accordance with the traveling position of the detector, and the plate-like body is obtained based on the calibration data. Is corrected, and the plate thickness of the plate is measured. Therefore, according to the present invention, it is possible to accurately measure the thickness of the plate-like body without increasing the processing accuracy and the assembly accuracy of the traveling route.

By the way, even if the calibration data of the traveling route is obtained, if there is a deformation due to a temperature drift of a detection system such as a detector or a data processing device or a rise in the temperature of the traveling route, the measurement accuracy can be obtained only by the calibration data of the traveling route. There is no guarantee that can be secured. Therefore, in one embodiment of the present invention, every time the sheet thickness is measured or every predetermined number of thickness measurements, the thickness of the reference plate is actually measured by the detector, and the actually measured thickness is compared with the actual thickness. The calibration data of the detector is obtained by comparing the calibration data of the detector and the actual measurement data of the plate-like body based on the calibration data of the traveling route, and the thickness of the plate-like body is measured. I have. Therefore, it is possible to more accurately measure the plate thickness of the plate-shaped body without trouble.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and an apparatus for measuring a plate thickness of a plate-like body according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of a hydraulic plate-like sheet thickness measuring apparatus to which the plate-like body thickness measuring apparatus of the present invention is applied, and FIG. 2 is a plate thickness measuring apparatus shown in FIG. FIG.

A sheet thickness measuring apparatus 10 shown in FIGS. 1 and 2 is an apparatus for inspecting the sheet thickness of a hydraulic plate-like body 12 used as a building material board on a production line. The hydraulic plate-like body 12 is press-formed from a hydraulic raw material into a hydraulic plate-like body, cured and hardened to produce a product, and its thickness is inspected at the time of transportation. The plate thickness measuring device 10 has a pair of distance sensors 14 and 16.
Sandwich the hydraulic plate-like body 12 up and down with the distance sensor 1
4 and 16 running simultaneously, the hydraulic plate-like body 1
The thickness in the width direction of No. 2 is measured.

The distance sensor 14 is, as shown in FIG.
It is arranged at an upper position with respect to the hydraulic plate-like body 12 and its detection surface 15 is attached downward. The detection surface 15 is provided with a laser oscillating portion and a light receiving portion, oscillates the laser from the oscillating portion toward the upper surface of the hydraulic plate-like body 12, and reflects the laser from the upper surface of the hydraulic plate-like body 12. The laser beam is received by the light receiving unit, and a signal indicating the distance YA from the upper surface of the hydraulic plate-like body 12 is output to the arithmetic unit 50 shown in FIG. The arithmetic unit 50 will be described later.

In FIG. 1, the distance sensor 14 is fixed to a head 18, and the head 18 is movably mounted on a traveling rail (traveling path) 20. The running rail 20 is disposed in the width direction (the direction orthogonal to the conveying direction) with respect to the hydraulic plate-shaped body 12 conveyed by the conveyors 22 and 24, and its end is fixed to the posts 26 and 28. . A belt 30 for moving the distance sensor 14 is provided inside the traveling rail 20, and the head 18 of the distance sensor 14 is attached to the belt 30. The left side of the belt 30 in FIG. 1 is wound around a pulley (not shown), and the upper end of the rotating shaft 32 is fixed to this pulley. The rotating shaft 32 is disposed vertically along the post 26, and a reduction mechanism 34 is provided at a longitudinal center portion thereof. An output shaft (not shown) of a motor 36 is connected to the reduction mechanism 34. Therefore, the motor 3
When the motor 6 is driven, the rotational force of the motor 36 is reduced by the reduction mechanism 34 and transmitted to the belt 30 via the rotary shaft 32 and the pulley. As a result, the belt 30 is circulated in the longitudinal direction of the traveling rail 20 and the distance sensor 14 is moved.
Moves along the traveling rail 20. The motor 36
Is reversed, the distance sensor 14 moves in the opposite direction.

On the other hand, as shown in FIG. 2, the distance sensor 16 is disposed at a position below the hydraulic plate-like body 12 and has a detection surface 17 attached upward.
The detection surface 17 is provided with a laser oscillating portion and a light receiving portion, oscillates a laser from the oscillating portion toward the lower surface of the hydraulic plate-like body 12, and reflects the laser reflected from the lower surface of the hydraulic plate-like body 12. Is received by the light receiving unit, and a signal indicating the distance YB to the lower surface of the hydraulic plate-like body 12 is obtained based on the light receiving angle in FIG.
Is output to the arithmetic unit 50.

In FIG. 1, the distance sensor 16 is fixed to a head 38, and the head 38 is movably mounted on a traveling rail (traveling path) 40. The running rail 40 is disposed parallel to the running rail 20, and its end is fixed to the posts 26 and 28. A belt 42 for moving the distance sensor 16 is provided inside the traveling rail 40.
Head 38 is attached. FIG. 1 of the belt 42
The middle left side is wound around a pulley (not shown), and the lower end of the rotating shaft 32 is fixed to this pulley. As described above, the rotation shaft 32 is provided with the speed reduction mechanism 34, and the output shaft of the motor 36 is connected to the speed reduction mechanism 34. Therefore, when the motor 36 is driven, the motor 36
Is reduced by the reduction mechanism 34 and transmitted to the belts 42 and 30 via the rotation shaft 32 and the pulleys.
Thereby, the distance sensor 16 moves along the traveling rail 40, and the distance sensor 14 similarly moves along the traveling rail 20 in the same direction as the distance sensor 16.

While the distance sensors 14 and 16 are moving, the distance YA from the distance sensor 14 to the upper surface of the hydraulic plate 12
Is output to the arithmetic unit 50 in FIG. 3, and at the same time, a signal indicating the distance YB to the lower surface of the hydraulic plate-like body 12 is output from the distance sensor 16 to the arithmetic unit 50. In the arithmetic unit 50, the two signals are amplified by the Amp 52 and converted into digital signals by the A / D converter 54, and then the CPU 5
The distances YA and YB are calculated by the arithmetic processing in step 6. And
The CPU 56 includes distance sensors 14 and 16 that are set in advance.
The distances YA and Y calculated from the distance L (see FIG. 2)
By subtracting B, the thickness t of the hydraulic plate-like body 12 is calculated. This calculation result is output to the external Prin via the I / F 58.
The data is output to the ter 60 and is printed out here. The CPU 56 controls the entire thickness measuring apparatus 10 as one. One of the CPU 56 is to control the rotation direction and rotation amount of the motor 36 (that is, the movement direction and movement amount of the distance sensors 14 and 16). Control.

The arithmetic unit 50 has two
RAMs 62 and 64 are built-in. The RAM 62 includes:
The processing data of the traveling system such as the traveling rails 20 and 40 and the posts 26 and 28 and the calibration data of the traveling system of the assembling accuracy are stored, and the RAM 64 detects the distance sensors 14 and 16 and the arithmetic unit 50 and the like. System calibration data is stored. Each calibration data stored in these RAMs 62 and 64 is
When the thickness is calculated by the CPU 56, the CPU 56
Is calculated by correcting the actually measured plate thickness based on each calibration data.

Next, a method of acquiring the calibration data of the traveling system will be described with reference to FIG. FIG. 4 is an explanatory diagram exaggeratingly expressing errors in machining accuracy and assembly accuracy of the traveling system in order to easily explain the errors. In the calibration data acquisition method shown in the figure, the master plate 68 on which the reference surface 66 is formed is attached to the distance sensor 14 via the holding member 70, and in this state, the distance sensors 14, 16
By simultaneously traveling in the same direction. That is, when the distance sensors 14 and 16 are driven, the distance signal Y1 from the distance sensor 14 to the master plate 68 is output from the distance sensor 14
, It does not change regardless of the position of the distance sensor 14 as shown in the graph of FIG. However, the distance signal output from the distance sensor 16 to the reference surface 66 of the master plate 68 changes according to the traveling position as shown in the graph of FIG. 5 (Y2 → Y3 → Y).
4). The amount of change corresponding to the traveling position is an error of the traveling system, and is stored in the RAM 62 as calibration data. The above is the method of acquiring the calibration data of the traveling system. Note that the number of calibration data acquisition points i is not limited to three, and it is preferable to acquire a large number of points.

Next, a method of obtaining calibration data of the detection system will be described with reference to FIG. FIG. 6 shows that the master plate 72 whose thickness is known in advance is
6 is a diagram showing a state where the master plate 72 is installed between start positions 6 and the thickness of the master plate 72 is actually measured by distance sensors 14 and 16. As shown in the figure, the master plate 72 is formed integrally with a thin portion 74 having a plate thickness t1 and a thick portion 76 having a plate thickness t2, and these portions 74 and 76 are provided for every single thickness measurement or It is actually measured by the distance sensors 14 and 16 at every predetermined number of thickness measurements. Preferably, t1 and t2 are set to the lower limit and the upper limit of the hydraulic plate-like body 12 to be measured.

FIG. 7 shows the thickness t of the master plate 72.
1, a measured value graph when t2 is actually measured, and the thickness t
It is explanatory drawing which compared with the true value graph of 1 and t2. As shown in the figure, the measured value graph is shifted from the true value graph. This may be caused by temperature drift of the detection systems such as the distance sensors 14 and 16 and the arithmetic unit 50 and the travel rails 20 and 40
This is because there is a deformation due to a rise in temperature.

Here, for example, t1 = 10 mm, t2 = 2
0 mm master plate 72 is attached to distance sensors 14 and 16
When t1 = 12 mm and t2 = 18 mm are measured at the time of actual measurement, (1) is used as calibration data of the detection system at this time.
The calculation formula of (0/6) a-10 (mm) is stored in the RAM 64. a is an actually measured value. Note that this calculation formula is updated each time the master plate 72 is actually measured. The above is the method of acquiring the calibration data of the detection system.

Next, the operation of the plate thickness measuring device 10 configured as described above will be described. First, in order to calibrate the traveling system, a master plate 68 shown in FIG.
6, distance sensors 14 and 16 at each traveling point while traveling
The distance data of the RAM 6 is obtained as calibration data.
Stored in 2. For example, in FIG. 5, the calibration data δi at the measurement point i is set as δi = Y2i−Y1i and the RAM 6
Stored in 2.

When the hydraulic plate-like body 12 is actually measured,
The calibration data is read from the RAM 62, and the error of the traveling system is corrected by adding or subtracting the calibration data δi to an actual measurement value corresponding to the measurement point i. Thus, even when the accuracy of the traveling system is not good, the thickness of the hydraulic plate-shaped body 12 can be accurately measured because the calibration data of the manufacturing and assembling accuracy is obtained in advance.

Further, according to the calibration method, even if the apparatus is disassembled and reassembled, the calibration data can be easily acquired by attaching and reacquiring the master plate 68. Can be shortened. The calibration data at each point cannot be obtained continuously, but by acquiring them at a short pitch, the calibration data for the measurement values at points that are not at It can be easily obtained by interpolation. Thereby, in the present embodiment,
The thickness of the hydraulic plate-like body 12 can be accurately measured without trouble.

By the way, even if the actual measurement data is corrected only with the calibration data, the data at the time of acquisition of the calibration data may change after the acquisition of the calibration data due to a temperature drift of the detection system or the like, and an error occurs. There are cases. Therefore, in the present embodiment, a master plate 72 whose thickness is accurately known is measured immediately before or immediately after the thickness is measured at a thickness near the upper and lower limits of the measurement range, and a straight line connecting the two points is measured. Are interpolated between them, and the corrected plate thickness is further corrected. Thereby, in the present embodiment, the thickness distribution of the hydraulic plate-like body 12 can be measured more accurately.

In the present embodiment, the measuring device for measuring the thickness of the plate-like body by sandwiching the plate-like body between the upper and lower distance sensors has been described. However, the present invention is not limited to this.
The present invention can also be applied to a measuring device that measures a plate thickness by placing a plate-like body on a surface plate and moving one distance sensor from above. In the case of this measuring device, the calibration data of the traveling system may be acquired using the surface of the surface plate as a reference surface.

[0027]

As described above, according to the method and apparatus for measuring the thickness of a plate-like body according to the present invention, calibration data of a traveling route with respect to a predetermined reference plane is obtained in advance in accordance with the traveling position of the detector. Since the actual measurement data of the plate is corrected based on the calibration data, the thickness of the plate can be accurately measured without any trouble.

Further, according to the present invention, the thickness of a reference plate is actually measured by a detector, the actually measured thickness is compared with the actual thickness to obtain calibration data of the detector, and the calibration data of the detector is obtained. Since the actual measurement data of the plate-like body is corrected based on the calibration data of the traveling route, the thickness of the plate-like body can be measured more accurately.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an apparatus for measuring the thickness of a plate-like body according to an embodiment of the present invention.

FIG. 2 is a side view of the thickness measuring apparatus shown in FIG. 1;

FIG. 3 is a block diagram of an arithmetic unit of the thickness measuring apparatus shown in FIG. 1;

FIG. 4 is an explanatory diagram for explaining an error of a traveling system such as a traveling rail.

FIG. 5 is a graph showing an error of a traveling system from a reference plane.

FIG. 6 is an explanatory view of actually measuring a master plate for acquiring calibration data of a detection system.

FIG. 7 is an explanatory diagram comparing a measured value graph and a true value graph of a master plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Plate thickness measuring device 12 ... Hydraulic plate-like body 14, 16 ... Distance sensor 20, 40 ... Running rail 56 ... CPU 62, 64 ... RAM

Claims (4)

[Claims] An apparatus for measuring a thickness of a plate by moving a detector for measuring the thickness of the plate along a traveling path arranged substantially parallel to the plate to measure a distance from the plate. In the method of measuring the thickness of a plate-like body, the calibration data of the traveling path with respect to a predetermined reference plane is obtained in advance in accordance with the traveling position of the detector, and the plate is measured based on the calibration data. A method for measuring the thickness of a plate-like body, comprising correcting actual measurement data of the plate-like body. 2. The apparatus according to claim 1, wherein the thickness of the predetermined reference plate is measured with the detector, and the measured thickness is compared with the actual thickness to obtain calibration data of the detector. 2. The method according to claim 1, wherein actual measurement data of the plate is corrected based on the calibration data of the traveling route. 3. A plate thickness measurement detector for a plate-shaped body is caused to travel along a traveling path arranged substantially parallel to the plate-shaped body, and a distance from the plate-shaped body is measured. A plate thickness measuring device for measuring a plate thickness of the body, wherein first calibration data acquiring means for acquiring calibration data of the traveling route with respect to a predetermined reference plane according to a traveling position of the detector; A first storage unit that stores the calibration data of the traveling route acquired by the first calibration data acquiring unit; and a calibration data of the traveling route that is stored in the first storage unit. The detector detects the calibration data based on the calibration data. And a first calculating means for correcting and calculating the measured data of the plate-shaped body measured in (1). 4. A second calibration for obtaining calibration data of the detector by comparing measured data obtained by actually measuring the thickness of the reference plate with the detector and the actual thickness of the reference plate. Data acquisition means; second storage means for storing the calibration data of the detector acquired by the second calibration data acquisition means; calibration data of the detector stored in the second storage means; And a second calculating means for correcting and calculating the actual measurement data of the plate-like body measured by the detector based on the calibration data of (c) and the calibration data of the traveling route. An apparatus for measuring the thickness of a plate-like body according to the above.