JPH05157550A - Method and apparatus for measuring shape of steel plate - Google Patents

Abstract

PURPOSE:To measure the shape of a steel plate accurately even if the steel plate is vibrated. CONSTITUTION:When a steel plate 5 after rolling passes transfer rolls 6, the distances to the steel plate 5 are continuously detected by distance detectors 1, which are provided at an equal interval at the same height over the transfer rolls 6 in the conveying direction, and the deflecting amount of the steel plate 5 is computed. The deflecting amount is used at the inclination of the tangent line of the shape of the steel plate 5. The bending amount of the steel plate 5 in the longitudinal direction is computed with a length gage 2, which is connected to the transfer roll 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to measuring the shape of a steel sheet after rolling.

[0002]

2. Description of the Related Art Conventionally, in order to measure the shape of a steel sheet, one distance detector is used, the distance from a certain reference point to the steel sheet surface of the steel sheet being conveyed is continuously measured, and the measured data are connected. Determine the steel plate shape in the transport direction by using, or use two distance detectors to continuously measure the distance from the two reference points lined up in the transport direction to the steel plate surface, and then calculate the difference between the two distance measurement values in the transport direction. The steel plate shape in the transport direction was obtained by integrating

[0003]

However, since the steel sheet actually conveyed oscillates on the table, vertical movement of the steel sheet or vibration of the head / tail of the sheet occurs. Therefore, an error occurs due to vibration in the detection distance, and an accurate shape cannot be obtained.

[0004]

Means for Solving the Problems The gist of the present invention is that when a rolled steel sheet passes over a conveyor roll, the steel sheet is detected by a distance detector installed at the same height above the conveyor roll and at equal intervals in the conveyor direction. Distance is continuously detected to calculate the amount of bending of the steel sheet, and the amount of bending is used as the inclination of the tangent line of the shape of the steel sheet, and the bending amount in the length direction of the steel sheet is calculated from the length meter connected to the conveyor roll. A method of measuring the shape of a steel sheet, which is characterized by calculating, and a distance detector is installed at the same height above the conveyor roll that conveys the rolled steel sheet and at equal intervals in the conveyor direction, and the length of the conveyor roll is set. Connect a meter to calculate the bending amount of the steel plate based on the detection value from the distance detector and calculate the bending amount in the length direction of the steel plate based on the bending amount and the detection value from the length meter. A steel sheet shape measuring device characterized in that A.

[0005]

Operation and Embodiments The operation of the present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a diagram showing an embodiment of the present invention.

The rolled steel plate 5 passes over the transport rolls 6. Several distance detectors 1 are installed above the steel plate 5 at the same height in the traveling direction of the steel plate at equal intervals. In order to detect the length of the steel plate 5, a pulse generator having a length meter 2 is connected to the transport roll 6. The data collected from the distance detector 1 at the same time is input to the arithmetic unit 3 to perform arithmetic. The result is sent to the output unit 4. The steel plate shape calculated by the output unit 4 is displayed. As the distance detector 1, a known distance detector such as a laser displacement meter or ultrasonic wave can be used. Also,
In the case of a thick plate, the shape in the rolling direction often changes at a period of about 1 m, so the detector interval, that is, the measurement interval is 100 to
It is good to set it to about 200 mm.

FIG. 2 is a flowchart showing a method for measuring the shape of a steel sheet according to the present invention.

First, the plate tip is checked to determine the measurement start point. You can judge this from the data,
A separate detector may be attached and used as a start trigger.

Detection is started, and the distance to the plate is simultaneously taken in as data l _1i , l _2i , l _3i ... From three or more detectors. Do this until the board passes, and stop collecting data when the board is gone. As the data sampling time is shorter, the number N of pieces of plate shape data can be obtained, so that a result closer to the actual plate shape can be obtained. It is necessary to pay attention to the limit of the detector regarding the sample time. For example, in the case of a laser displacement meter,
It is possible up to about 0 msec.

Next, the amount of deflection is calculated from this data. The amount of deflection B is how much the plate is warped between the detectors. When the distance between the detectors is d, the amount of deflection B can be calculated by Equation 1.

[0012]

[Equation 1]

This is repeated for the number of data N, and B ₁ , B
_2, B _3, ..., to seek and B _N.

The plate shape is calculated from this deflection amount B. The detailed calculation method will be described with reference to FIG.

FIG. 3 is a diagram for explaining the principle of obtaining the deflection amount of the plate.

For example, three distance detectors D ₁ , D ₂ , D
The distances from ₃ to the plate are l ₁ , l ₂ and l ₃ , respectively,
The warp between D ₁ and D _{3 is} the amount of deflection. This deflection amount can be easily obtained because the detectors are evenly spaced. However, in this figure, although it is made extremely large for the sake of clarity, the actual amount of deflection is very small.

FIG. 4 is a diagram showing a method for calculating the shape from the amount of deflection.

As a reference line, a line having a slope of the equation 2 is drawn. Next, draw a line having a slope of several 3 from the B ₁ measurement point. Similarly B
Draw a tangent line with a slope of 4 from ₂ points. The slope of the tangent line drawn from the B _N point is given by Equation 5. By repeating this, the tangent lines gather to form a plate shape.

[0019]

[Equation 2]

[0020]

[Equation 3]

[0021]

[Equation 4]

[0022]

[Equation 5]

FIG. 5 is an explanatory diagram of coefficients used in the shape calculation.

The measurement range is such that the shape change of the steel plate is several mm / m.
Since the distance between the distance detectors is 100 to 200 mm, it can be assumed to be a minute arc on a circle having a large radius. The deflection amount B in the figure corresponds to A, and the coefficient of inclination can be calculated by knowing A: B. Since it is a minute arc, and Δabc and Δaeb are similar, B:
Since C = 4: 1 and A≈C, A: B =
It will be 1: 4. Therefore, in order to obtain the tangent line from the amount of deflection, the amount of deflection is multiplied by a factor of four.

[0025]

According to the present invention, the shape of a steel sheet can be obtained without causing a measurement error due to the vibration of the steel sheet.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a flowchart of a method for measuring the shape of a steel sheet according to the present invention.

FIG. 3 is a diagram for explaining the principle of obtaining the deflection amount of a plate.

FIG. 4 is a diagram showing a method for calculating a shape from a deflection amount.

FIG. 5 is an explanatory diagram of coefficients used in shape calculation.

[Explanation of symbols]

 1 distance detector 2 length meter 3 arithmetic unit 4 output unit 5 steel plate 6 transport roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Mizutani 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Kimitsu Works

Claims (2)

[Claims] 1. When a rolled steel sheet passes over a conveyor roll, the distance to the steel sheet is continuously detected by a distance detector installed at the same height above the conveyor roll at equal intervals in the conveyor direction. Shape of steel sheet characterized by calculating the amount of deflection of the steel sheet, using the amount of deflection as the inclination of the tangent to the shape of the steel sheet, and calculating the amount of bending in the length direction of the steel sheet from the length meter connected to the transport roll. Measuring method. 2. A distance detector is installed at the same height above the conveying roll for conveying the rolled steel sheet and at equal intervals in the conveying direction, and a length meter is connected to the conveying roll to detect the distance from the distance detector. Shape of steel sheet characterized by including a computing device for calculating the amount of deflection of the steel sheet based on the detected value and for calculating the amount of bending in the length direction of the steel sheet based on the amount of deflection and the detected value from the length meter measuring device.