JP2619026B2 - Measuring method of bending amount of strip transport roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a strip transport roll (hereinafter referred to as a roll).
And a method for measuring the amount of bending.

2. Description of the Related Art A large number of rolls are used to transport a strip in various strip processing lines.

For example, although FIG. 3 shows a part of a continuous annealing furnace, a predetermined heat treatment is performed while the strip S is sequentially wound around a number of rolls 1 and transported.

By the way, such a roll often bends. The causes of bending include mechanical distortion and thermal distortion, but in any case, if the roll bends, the strip will meander, and if the roll is installed in a furnace, further heat buckles will occur. Seriously hinder production. Therefore, it is necessary to periodically measure the roll bending and manage the roll.

FIG. 4 shows a method for measuring the amount of bending of the roll. That is, the stretch 2 is applied to the roll 1 in the axial direction, and the gap δ is measured.

There is also a method shown in FIG. For this, the displacement gauge 3 is installed at the axial center position of the roll 1, and the distance from the displacement gauge 3 to the roll 1 when the roll 1 is rotating is measured.
And requests the curve amount [delta] from the difference between the maximum measured value l1 and minimum measured values l ₂ ([delta] = a l ₁ -l _2/2).

<Problem to be Solved by the Invention> However, the method shown in FIG. 4 requires stopping the equipment, which hinders productivity. In addition, the workload is heavy, and the rolls in the furnace are even more troublesome.

The method shown in FIG. 5 has the advantage that it can be carried out without stopping the equipment, but has the following disadvantages. That is, the measured value differs depending on the mounting position of the displacement meter, and the measured value fluctuates when there is vibration. Furthermore, when installing in a furnace, heat measures such as water cooling are required,
Practical application is difficult.

An object of the present invention is to solve the above-mentioned problems of the conventional technology.

<Means for Solving the Problems> According to the present invention, in a method for measuring the amount of bending of a strip carrying roll whose both ends are rotatably supported by bearings, the vibration acceleration of at least one of the bearings of the bearing and the vibration of the strip carrying roll. The peripheral speed is measured, and the bending amount of the strip transport roll is calculated using the measured values.

<Operation> The principle of the present invention will be described below. Now, assuming that the vibration acceleration detected by the vibration acceleration sensor attached to the roll bearing is G (g), the vibration drag R (kg) is calculated by the following equation.

Here, W: the roll's own weight (Kg) On the other hand, the centrifugal force F (Kg) due to the eccentricity of the roll is calculated as follows. First, as shown in FIG. 2, the deflection of the roll is linearly approximated, and the load is uniformly distributed. When the roll eccentricity is e (cm), the centrifugal force F (Kg) due to the roll eccentricity is calculated by the following equation.

Here, g: gravity acceleration (= 980 cm / sec ² ) W: roll's own weight (kg) ω: angular velocity (rad / sec) The angular velocity ω (rad / sec) can be calculated by the following equation.

Here, N: roll rotation speed (rpm) D: roll diameter (m) υ: roll peripheral speed (m / min) Accordingly, the following formula is obtained from formulas (2) and (3).

Therefore, it can be considered as R 、 F, (1),
The following equation is obtained from the equation (4).

From the above, since the roll diameter D (m) is known in advance, the roll peripheral speed υ (m / min) and the vibration acceleration G (g) are measured, and the calculation based on the equation (5) is performed using these measured values. By doing so, the roll eccentricity e (cm) can be obtained.

Embodiment An embodiment according to the present invention will be described with reference to FIG.
The roll 1 is supported by bearings 4 and 4 at both ends, and a coupling 5
, And is rotationally driven by the motor 6. A speed detector 7 is connected to the rear end of the motor 6, and a vibration acceleration sensor 8 is installed on the bearing 4. Then, based on the output signal from the sensor 8, the vibration meter 9 calculates the vibration acceleration G
Is output to the computing unit. The arithmetic unit 10 uses the previously input roll diameter D (m), the vibration acceleration G (g), and the roll peripheral speed (m / min) based on the above-described equation (5). The roll eccentricity e (cm) is calculated.

Such roll eccentricity e calculated by the is compared with the reference value e _alpha which is determined in advance, if _{e> e α ...... (6)} , and alarm or roll inspection requirements by the output device 11 Output, display, etc. The roll eccentricity e is also displayed on the output device 11.

 Next, specific examples will be described.

The present invention was applied to a roll having a roll diameter of 250 mm and a roll body length of 2000 mml. The reference value _e α at this time was set to 1.2cm. When an alarm was issued, an investigation revealed that the roll peripheral speed 500 was 500 m.
/ min and the indicated value of the roll eccentricity e were 1.3 cm. When the roll was stopped and the roll eccentricity was actually measured by the method shown in FIG. 4, it was 1.35 cm, which was in good agreement with the displayed value.

In the above embodiment, the sensor 8 is installed on only one of the bearings 4. However, the sensor 8 may be installed on both bearings and the average value of the measured values may be used. Further, in this case, if the installation positions are different between the two sensors, it is preferable because correction is performed. Further, the case where the reference value is one level has been described, but may be two or more levels. For example, it is conceivable to use two levels of a strip meandering occurrence limit value and a roll breakage limit value as reference values.

<Effects of the Invention> According to the present invention, the amount of bending (eccentricity) of the roll can be easily measured without stopping the roll, and by measuring the vibration acceleration from the bearing outside the furnace even in the case of the roll inside the furnace. It becomes possible to measure.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of one embodiment of the present invention, FIG. 2 is a side view of a roll for explaining the principle of the present invention, and FIG. 3 schematically shows a roll used in a continuous annealing furnace. Explanatory diagram,
4 and 5 are explanatory diagrams of a conventional roll bending amount measuring method. 1 ... roll, 4 ... bearing, 5 ... coupling, 6 ... motor, 7 ... speed detector, 8 ... vibration acceleration sensor, 9 ... vibrometer, 10 ... arithmetic unit, 11 ... Output device.

Claims (1)

(57) [Claims] In a method for measuring a bending amount of a strip carrying roll whose both ends are rotatably supported by bearings, a vibration acceleration of at least one bearing portion of the bearing and a peripheral speed of the strip carrying roll are measured. A method for measuring the amount of bending of the strip transport roll, wherein the amount of bending of the strip transport roll is calculated using a measured value.