JPS62193772A - Roll grinding control method and device thereof - Google Patents

Abstract

PURPOSE:To grind a roll with the desired accuracy even during strip rolling, by controlling the extent of stock removal per rotation in the roll to be constant, while finishing the grinding at a time when a roll revolving speed from grinding starting time accords with the required roll revolving speed. CONSTITUTION:Peripheral velocity of a roll 2 during grinding operation, for example, a rolling speed is detected and calculated, and on the basis of this operation value, pressing force of a grinding wheel 1 to the roll 2 is controlled by a pressure control mechanism 9, whereby grinding takes place so as to cause stock removal per rotation in the roll to become constant. A rolling number detecting integration mechanism 14 gives a signal to the pressure control mechanism 9 when the integrating value of roll rolling numbers after a grinding start accords with the required roll rolling numbers, and the pressure control mechanism 9 releases the pressing force of the grinding wheel 1, thus grinding is over. Therefore, the desired stock removal is controllable with the detecting and integrating values of rolling numbers of the roll without requiring any high processing and control, and even in case of an on-line, it is easily grindable in an accurate manner.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for controlling the grinding of a roll incorporated in a rolling mill or the like for rolling metal strip or the like.

The present invention applies not only to rolling rolls but also to various process lines,
For example, the present invention can also be applied to a method and apparatus for controlling roll grinding in a line for strip pickling, coating, heat treatment, etc.

<Prior Art> In a rolling mill, for example, a strip hot rolling mill, generally only the portion of the rolling roll that contacts the strip wears locally, and a step is created between the portion that does not contact the strip. Ru. Also, many cranks, so-called rough skins, occur on the roll surface that comes into contact with the hot strip. If the strip is rolled with these steps and rough skin, these will be transferred to the strip as they are. Therefore, in order to prevent the step difference from being transferred to the strip, rolling is usually performed according to a rolling schedule in which the width of the strip to be rolled is gradually reduced.

In addition, if the roughness of the surface exceeds an allowable value, the rolls are replaced with new rolls. However, in such a method,
There were many problems, such as not only the efficiency of rolling operations being hindered, but also the inability to perform rolling according to an arbitrary rolling schedule.

In order to solve this problem, in recent years, the roll rolls have been ground while still installed in the rolling mill to remove the above-mentioned steps and rough surfaces, thereby extending the life of the rolls until they are reassembled and making it possible to roll according to any rolling schedule. Various online grinding methods for rolling rolls have been proposed.

The amount of grinding in these conventionally proposed mill roll grinding methods is determined by [amount of grinding - amount of cut x residence time], as disclosed in, for example, Japanese Patent Laid-Open No. 60-124410. There is. Here, the depth of cut indicates the amount of grinding per unit time under predetermined grinding conditions, and the residence time indicates the contact time of the abrasive material with the surface of the rolling roll, that is, the time during which grinding is performed. As described above, in conventional methods for grinding rolls, the amount of grinding is controlled based on time.

<Problems to be Solved by the Invention> The conventional method of determining the amount of grinding based on time has the following drawbacks.

In other words, the factors that determine the amount of grinding are: 1) Specifications of the abrasive material (grain size, degree of bonding, etc.) 2) Grinding speed (rotational speed of the rolling roll) 3) Pressure force of the abrasive material against the rolling roll 4) Grinding style ( Shape of abrasive material, drive method, etc.) 5) Material of rolling roll and presence or absence of lubricating oil, etc. Among the above factors, items 1) and 3) to 5) can be determined by initial selection. There is no problem in considering it as a fixed condition factor.

However, the grinding speed in item 2) is the rolling speed,
Since this is a variable condition factor whose value always changes, some kind of countermeasure is required.

In other words, when grinding is carried out under a constant rolling speed, that is, a constant grinding speed, all of the factors in items 1) to 5) above become fixed condition factors, and the amount of grinding increases in proportion to time. Control can be performed easily.

However, when grinding the rolling rolls during strip rolling, the rolling speed VR is not constant, as shown in Figure 4, an example of how the rolling speed changes with time t. After starting, change the speed to the plate threading speed■□
maximum adapted rolling speed of the strip from V IIM
After increasing to AX and rolling for a predetermined time, the rolling end speed V
It is common to adopt a speed pattern in which the speed decreases to 12.

When determining the amount of grinding based on such a speed pattern, the basic value of the depth of cut, that is, the amount of grinding per unit time, changes with the above-mentioned time pattern. Therefore, in order to obtain the required residence time to obtain the required grinding amount, advanced calculations such as integrating the depth of cut using the speed pattern described above and performing convergence calculation between the residence time and the Requires control. This problem can be solved by grinding the strip for a period when the grinding speed can be kept constant, that is, while the strip is not being rolled.However, in practice, in order to improve productivity, the time required for grinding is It is difficult to determine this while not rolling, and it is necessary to perform grinding during rolling.

The present invention has been made in view of the above-mentioned conventional problems, and does not require sophisticated calculations and control as in the conventional methods, can perform grinding with desired accuracy even during strip rolling, and does not require a large amount of work. It is an object of the present invention to provide a grinding control method for rolling rolls that does not require equipment costs, and an apparatus for the same.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the roll grinding control method according to the present invention changes the pressing force of the abrasive material against the roll according to the circumferential speed of the roll, thereby increasing the speed per rotation of the roll. In addition to controlling the amount of grinding to a constant value, the number of roll rotations required to obtain a predetermined amount of grinding is determined, and the grinding is finished when the number of roll rotations from the start of grinding matches the required number of roll rotations. It is characterized by causing

Further, the roll grinding control device according to the present invention includes a pressing force detection mechanism that detects the pressing force of the abrasive material against the roll, a speed calculation mechanism that calculates the circumferential speed of the roll from the roll rotation speed,
A rolling number detection and integration mechanism detects and integrates the rolling number of the roll during grinding, and the amount of grinding per roll rotation is kept constant based on the detected value of the pressing force detection mechanism and the calculated value of the speed calculation mechanism. Pressure to control the pressing force of the abrasive material and release the pressing force of the abrasive material by a signal from the rolling number detection and integration mechanism when the cumulative value of the roll rolling number matches the required roll rolling number. A control mechanism is provided.

<Function> In the present invention configured as described above, the circumferential speed of the roll during grinding, that is, the rolling speed, for example, is detected and calculated, and the pressing force of the abrasive material against the roll is controlled by the pressure control mechanism based on this calculated value. Grinding is performed by controlling the amount of grinding per rotation of the roll to be constant. The rolling number detection integration mechanism gives a signal to the pressure control mechanism when the cumulative value of the roll rolling number after the start of grinding matches the required roll rolling number, and the pressure control mechanism releases the pressing of the abrasive material and stops grinding. finish.

<Example> Hereinafter, the configuration of the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a rolling roll grinding apparatus that uses a cup-shaped grindstone as the abrasive material and presses the grinding wheel against the circumferential surface of the rolling roll for grinding.

In the figure, a cup-shaped grindstone 1 is pressed against the surface of a rolling roll 2 to perform grinding.

The cup-shaped grindstone 1 is rotatably mounted on a grindstone support box 4 via a bearing 3, and the grindstone support box 4 is moved in the direction of arrow A by a hydraulic cylinder 5.
be forced to. The hydraulic cylinder 5 is operated by supplying and discharging pressure oil through oil supply pipes 6 and 7, and the pressing force of the grinding wheel 1 against the rolling roll 2 is detected by a pressure detection mechanism 8 attached to the oil supply pipe 7, and its value is determined by pressure. It is controlled to an arbitrary value by the control mechanism 9. The grinding wheel 1 is arranged so that its rotating shaft is inclined by an angle α with respect to the axial line of the rolling roll, and is moved by a moving device (not shown) in the axial direction of the rolling roll 2 shown by an arrow B to the position of the grinding wheel 1' shown by a chain line. It can be moved by the amount of movement LP.

The rolling roll 2 is attached to a rolling mill housing (not shown) via a bearing 10, and is rotationally driven by a rotation drive bag W11.The rotational speed NR of the rolling roll 2 is detected by a rotational speed detection mechanism 12, and the speed is calculated. The mechanism 13 calculates the circumferential speed VR1 of the rolling roll 2, that is, the rolling speed, using the following equation.

■R=π·DR' NR Here, DR is the average diameter of the rolling roll 2, and NR is the number of rotations. Furthermore, rolling number detection integration mechanism 1 of rolling roll 2
4, it is detected that the rolling roll 2 has made one rotation, and the number of rotations thereof is accumulated. Note that the roll rolling number is the cumulative number of rolls in the process.

In such an apparatus configuration, the mill roll grinding apparatus is controlled as described below to carry out grinding.

By a moving device (not shown), the grindstone 1 is reciprocated in the direction of arrow B within a range of .

This movement continues during grinding. Next, pressure oil is sent to the oil supply pipe 7, the hydraulic cylinder 5 is operated, the grinding wheel 1 is pressed against the rolling roll 2, and grinding is started. This start of grinding is detected by the pressure detection mechanism 8, and the rolling number detection and integration mechanism 13 of the rolling roll 2 starts operating based on this detection signal. Grinding is continued until the detection and integrated value of the rolling number of the rolling roll 2 matches the required rolling number N3 of the rolling roll 2 necessary for grinding by a predetermined amount determined in advance. When they match, the pressure control mechanism 9 operates the hydraulic cylinder 5 in the opposite direction to the pressing time based on the signal from the rolling number detection and integration mechanism 13, releases the pressing, and finishes the grinding.

The required rolling number N3 of the rolling roll 2 is determined by the following formula.

W, G.

Here, W6: Effective grinding width of grinding wheel l (1 wheel) Ga:
Desired amount of grinding (,1) G9: Amount of grinding per one rotation of the rolling roll (dragon) k: Coefficient Figure 2 shows the amount of grinding per rotation of the rolling roll obtained from the grinding experiment using the grinding device shown in Figure 1. The relationship between the per grinding amount G9 and the rolling speed (peripheral speed of the rolling roll during grinding) VR is shown.

In the experiment, the grinding wheel f was set when the pressing force F9 of the grinding wheel 1 was kept constant.
a), was carried out on the grindstone [bl]. The grindstone (al) is a grindstone with a soft bonding degree, and the grindstone (bl is a grindstone with a hard bonding degree. With the grindstone fat, as the rolling speed vR increases, the grinding amount G9 per rotation of the rolling roll tends to decrease slightly. However, in the rolling speed range up to the normal l 40 Cm/min, it was found that the value was almost constant.On the other hand, in the case of a grindstone (BL), the higher the rolling speed It was observed that the amount of grinding G9 per rotation of the roll decreased significantly.This result was observed in grinding experiments using grindstones with various degrees of bonding, and in grinding experiments in which the pressing force F9 was changed. It turns out that nothing has changed.

From the above, if the grindstone (a) with a soft bond is used, the amount of grinding G9 per roll rotation is almost constant regardless of the rolling speed ■8, and the number of rolling rotations of the rolling roll 2 can be detected and integrated. It can be seen that the value can be used to control the grinding amount to a desired amount, t3.

On the other hand, in the case of a grindstone fb) with a hard bonding degree, as a result of organizing various experimental data, the amount of grinding G per rotation of the rolling roll is
9 (Whetstone for rolling speed VR when keeping constant)
It has been found that the relationship between the pressing force F9 in b) is as shown in FIG.

In other words, if the pushing force Fg is increased or decreased as the rolling speed increases or decreases, the grinding force per rotation of the rolling roll increases or decreases.
It can be seen that 9 can be kept constant.

Based on the above facts, when using the grindstone (b) with a hard bond, in the device shown in No. 1M, the rolling speed during grinding is detected by the rotation speed detection mechanism 12 and the speed calculation mechanism 14 is used.
Based on this calculated value, the hydraulic pressure supplied to the hydraulic cylinder 5 is increased or decreased by the pressure control mechanism 9 to push the grinding wheel fhl (if the grinding wheel F9 is controlled, the grinding amount per rotation of the rolling roll can be increased or decreased).
It is clear that grinding can be performed under grinding conditions where c q is constant, and that it is possible to control the grinding amount by a desired amount by detecting the number of rotations of the rolling roll 2 and using the integrated value.

As is clear from the above description, the roll grinding control method and device according to the present invention are not only applicable to the mill roll grinding device shown in FIG. Even if the device, for example, has a cylindrical or rod-shaped grindstone, or uses a cloth-like abrasive material,
Moreover, it can be widely applied regardless of whether or not the abrasive material is driven. Furthermore, as for the hardness of the abrasive material, any abrasive material can be used by manually inputting a required coefficient into the speed calculation mechanism.

On the other hand, known methods and means can be applied to the means for pressing the "grinding" onto the rolling rolls and various detection and calculation means, and no special ones are required.

The present invention is applicable not only to mill roll grinding devices but also to roll surface grinding devices in various strip processing lines, such as strip pickling lines, mesoki lines, and heat treatment lines.

<Effects of the Invention> As specifically explained above, according to the present invention, - the rolling number of rolls can be detected and the desired amount of grinding can be controlled using an integrated value without requiring sophisticated calculation processing or control; In addition, it is possible to easily perform accurate grinding even online.

Therefore, it is possible to provide a roll grinding control method and apparatus that are extremely effective in practice, especially when applied to the grinding of rolling rolls that are still installed in a rolling mill.

[Brief explanation of drawings]

Fig. 1 shows an example of a rolling roll grinding device to which the present invention is applied, and Fig. 2 shows the influence of the degree of bonding of the grinding wheel on the relationship between rolling speed ■ and grinding [09] per rotation of the rolling roll. Figure 3 shows the relationship between the rolling speed ■ and the grinding wheel pressing force F9 when the amount of grinding G9 per rotation of the rolling roll is constant, and Figure 4 shows the temporal change in the rolling speed ■. It is a figure showing an example of a pattern. In the figure, ■ is the abrasive material, 2 is the rolling roll, 5 is the hydraulic cylinder, 8 is the pressure detection mechanism, 9 is the pressure control mechanism, 12 is the rotation speed detection mechanism, 13 is the speed calculation mechanism, 14 is the rolling speed detection It is an accumulation mechanism.

Claims (2)

[Claims] (1) By changing the pressing force of the abrasive material against the roll according to the circumferential speed of the roll, the amount of grinding per rotation of the roll is controlled to be constant, and the number of roll rotations required to obtain the specified amount of grinding is determined. . A roll grinding control method, characterized in that grinding is ended when the number of roll rotations from the start of grinding matches the required number of roll rotations. (2) A pressing force detection mechanism that detects the pressing force of the abrasive material against the roll, a speed calculation mechanism that calculates the circumferential speed of the roll from the roll rotation speed, and a rolling mechanism that detects and integrates the rolling speed of the roll during grinding. The pressing force of the abrasive material is controlled so that the amount of grinding per rotation of the roll is constant based on the number detection and integration mechanism, the detected value of the pressing force detection mechanism, and the calculated value of the speed calculation mechanism. A roll grinding control device comprising: a pressure control mechanism that releases the pressing of the abrasive material in response to a signal from the rolling number detection and integration mechanism when the cumulative rolling number matches the required roll rolling number. .