JPH09164407A - On line grinding method of rolling roll at steel sheet rolling mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excess grinding at an inclined wear part and to obtain a prescribed roll profile in high precision by decreasing pressing force of a grinding stone gradually at the inclined wear part in on line grinding of rolling roll. SOLUTION: Roll grinding attachments 4a, 4b are arranged approaching to an upper work roll 1o and a lower work roll 1u of a rolling mill. The roll grinding attachments provide rotating grinding stones 6 reinforced with steel discs 5 on back faces thereof and grinding heads 7a, 7b having pressing control mechanisms of this grinding stones 6. This grinding stones 6 are made move in parallel with the roll shaft and pressing force is given and thereby rolls are ground. In this case, the pressing forces to the grinding stones 6 are gradually reduced from wearing starting point to wearing end point, in the inclined wearing area causing incomplete contact from the wearing starting point to the wearing end point and the pressing force is controlled so as to be zero at the wearing end point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-line grinding method for rolling rolls of a steel plate rolling machine, and more specifically, to a non-wearing flat surface, an inclined wear surface and a wear flat surface formed on the outer peripheral surface thereof. The present invention relates to an on-line grinding method for a rolling roll in a steel plate rolling machine applied when the rolling roll is subjected to on-line grinding using a grinding device.

[0002]

2. Description of the Related Art Conventionally, a flat roll having a flat outer peripheral surface has been used as a rolling roll used in a steel sheet rolling machine. When this flat roll is used for rolling, the rolling roll is a sheet passing portion. It is known that there is a step between the non-threaded plate part that wears and the non-wearing plate part that does not wear, and if the wear amount exceeds the allowable range, the roll profile deteriorates and the product shape and quality deteriorate. When the amount of wear exceeds the allowable range, rolling rolls are replaced or roll grinding is performed online or offline to continue rolling.

Generally, in a steel plate rolling machine, in order to reduce the frequency of roll replacement and ensure sufficient rolling productivity, rolling is performed in order from the largest sheet width and the same flat surface is used as it is. It is customary to set up a rolling schedule capable of coping with multiple sizes with the above rolls. In such a case, it is necessary to arrange a grinding device between rolling mills and grind the worn rolling rolls online.

For example, in Japanese Unexamined Patent Publication No. 6-190410, as shown in FIG. 7, a grinding device e is disposed in the vicinity of a rolling mill f, and a rotary grindstone i of the grinding device e is pressed against a rolling roll g to roll the rolling roll. Online grinding is disclosed. However, in this grinding method, there is no problem in the case of grinding the entire surface of the rolling roll, but there is no mention of the case of online grinding only the non-wearing flat surface including the inclined wear surface as the grinding area. In the case of grinding a flat surface grinding region, it cannot be said that measures against excessive grinding have been taken, and there is a concern that the accuracy of grinding may decrease and the roll profile may deteriorate.

This tendency is particularly noticeable in the case of performing grinding with a constant pressing force using a grinding machine equipped with a grindstone of a fixed pressing angle against a rolling roll. That is, in the boundary area between the unworn flat surface and the worn flat surface, the roll profile changes rapidly, and when the pressing force against the roll of the grindstone is constant, the contact area of the grinding wheel with the roll becomes small, and The amount increases and excessive grinding is performed, and in particular, a grinding step may occur due to excessive grinding of the inclined wear surface, and a predetermined roll profile cannot be obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to a case where a rolling roll of a steel plate rolling machine in which an inclined wear surface is formed between an unworn flat surface and a worn flat surface is subjected to on-line grinding by a grinding device. Provided is an online grinding method for a rolling roll in a steel plate rolling machine, which can prevent excessive grinding at the surface and the boundary between the inclined wear surface and the flat surface and can obtain a predetermined roll profile with high accuracy and high productivity. is there.

[0007]

Means for Solving the Problems The first invention of the present invention is:
An online grinding method for rolling rolls in a steel plate rolling machine in which a roll grinding device is arranged between rolling stands of a steel plate rolling mill. In the case of grinding toward the surface of the grinding wheel, the pressing force of the grinding wheel is gradually reduced from the boundary between the unworn flat surface and the inclined wear surface to the boundary between the inclined wear surface and the worn flat surface while gradually decreasing to the prescribed pressing force on the worn flat surface. An on-line grinding method for rolling rolls in a steel plate rolling machine, comprising:

A second aspect of the present invention is an on-line grinding method for a rolling roll in a steel plate rolling machine in which a roll grinding device is arranged between rolling stands of the steel plate rolling machine to grind the rolling roll online. When grinding from a surface to an unworn flat surface through an inclined wear surface, the pressing force of the grinding wheel is gradually not worn from the boundary between the worn flat surface and the inclined wear surface to the boundary between the inclined wear surface and the unworn flat surface. This is an online grinding method for a rolling roll in a steel plate rolling machine, which is characterized in that grinding is performed while gradually increasing to a predetermined pressing force on a flat surface.

According to the present invention, when performing on-line grinding of the rolling roll of the steel plate rolling machine by the grinding device, the pressing force of the grinding wheel on the inclined wear surface formed between the unworn flat surface and the worn flat surface is By reducing or increasing, excessive grinding at the boundary between the inclined wear surface and the flat surface can be prevented, and a predetermined roll profile can be obtained with high accuracy and high productivity.

As a result of various studies, the inventors of the present invention have conducted various studies on the problem of performing on-line grinding of a rolling roll of a steel plate rolling machine in which an inclined wear surface is formed between an unworn flat surface and a worn flat surface by using a grinding device. When the pressing angle of the grinding wheel with respect to the roll is fixed and reciprocating in parallel to the roll axis direction for grinding, the grinding wheel causes a one-sided contact phenomenon, the pressing area decreases, and the pressing force (load As a result, excessive grinding occurs, and in particular, a step due to excessive grinding occurs on the inclined wear surface, and it has been found that a predetermined roll profile cannot be obtained accurately. The present invention
It is based on this knowledge, and its main purpose is to prevent the occurrence of excessive grinding due to the one-sided contact phenomenon of the grindstone on the inclined wear surface.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be outlined below with reference to FIGS. This example is a case where the present invention is applied to online grinding of a rolling roll in a hot finish rolling mill, and in order to change the plate width of a steel sheet from small to large, a non-wearing flat surface and an inclined wear surface are ground. This is for online grinding as a region.

FIG. 1 conceptually shows an example of arrangement of a rolling roll to be ground and a grinding apparatus for carrying out the present invention. In FIG. 1, 1o is an upper work roll, 1u is a lower work roll 1u, and backup rolls 2o, 2u are arranged in contact with the backs of these work rolls. The shafts of these rolls are mounted on a finish rolling stand (not shown) via roll chocks (not shown). The rolled material 3 is rolled between the upper work roll 1o and the lower work roll 1u to become a steel plate 3s.

Reference numerals 4a and 4b denote roll grinders arranged near the upper work roll 1o and the lower work roll 1u.
A disk-shaped rotary whetstone 6 whose back surface is reinforced with a steel disk 5,
A grinding head 7a having this rotating grindstone pressing control mechanism,
7b, it does not have a structure for varying the contact angle θ of the rotary grindstone 6 with respect to each work roll (herein, the work roll 1o is representatively described for convenience).

As shown in FIG. 2, the grinding devices 4a and 4b are engaged with and arranged transversely on traverse rails 8 arranged parallel to the upper work roll 1o, respectively. One side 1 of the upper work roll 1o to be ground
The online grinding of the -1 region is shared, and the grinding device 4b is responsible for the online grinding of the 1-2 region on the other side.

On-line grinding of the upper work roll 1o by this grinding device is performed by pressing the grinding wheel of the grinding head of the grinding device with a predetermined pressing force against the outer peripheral surface of the rolling roll 1 which rotates while the rolling mill is in operation. This can be done by reciprocating in the axial direction of 1o.
In the figure, 1s is a roll shaft, and 9 is a roll chock.

FIG. 3 shows a wear shape of the upper work roll 1o and an operation example of the grinding heads 7a and 7b of the two grinding devices 4a and 4b arranged in parallel in the axial direction of the upper work roll 1o. In the rolling schedule of, as mentioned above,
In order to greatly change the plate width of the steel plate, online grinding is performed by two grinding devices on the unweared region 1x and the inclined wear region 1t until a flat surface 1h continuous with the worn face 1f of the worn region 1z is formed. An example is shown in which the passage width is expanded from a0 to a1. In this case, the online grinding area is the changed width a1, the inclined wear angle θt, and the non-wear surface 1
It is determined by the distance from a to the steel plate passing surface (wear surface) 1f, that is, the wear amount (depth) ΔCw. Here, the unweared area 1x and the inclined wear area 1t are used as grinding areas, and online grinding is performed until a flat surface 1h that is continuous with the worn surface 1f of the wear area 1z is formed, and the steel plate passing corresponding to the changed steel plate width is performed. A plate width a1 is formed.

FIG. 4 shows an unweared area 1x and an unweared area 1
x in the inclined wear region 1t formed between the wear region 1z and the grinding wheel 6 of the grinding device 4a and the upper work roll 1o.
The contact state with the peripheral surface is shown. Here, the grinding wheel 6 has a polishing width of about 40 mm,
This grinding wheel moves in parallel with the axis of the upper work roll 1o and comes into contact therewith. Therefore, when grinding an inclined wear region, the grinding direction (unwear region side → wear region side, wear region side → unwear region side) ), The grinding width (area) of the grinding wheel changes in the process of reaching the wear start point and the wear end point, and when the pressing force P of the grinding wheel is constant, the grinding amount changes. .

That is, since the grinding wheel is moved in parallel with the roll axis and the pressing force P is applied to perform grinding, the grinding wheel 6 hits one side in the inclined wear region 1t from the wear start point A to the wear end point B. Then, assuming that the contact width is d, a concentrated load of (40 / d) times is generated at this contact portion, and an excessive grinding phenomenon occurs.

Therefore, according to the present invention, as shown in FIG. 5, the pressing force P of the grinding wheel 6 is worn in the inclined wear area 1t from the wear starting point A to the wear ending point B which causes the partial contact of the area grinding wheel 6 to wear. The pressing force P is controlled so that it gradually decreases from the starting point A to the wear end point B and becomes 0 at the wear end point B.

However, from the worn area 1z side to the unweared area 1
When grinding on the x side, the pressing force P of the grinding wheel 6 is set to 0 at the point B and gradually increased to the point A.
The pressing force P is controlled so as to obtain the pressing force for grinding.

The control of the pressing force P can be performed, for example, by the procedure shown in FIG. That is, the pressing force and the pressing force change point of the unweared area are calculated from the plate width a1 of the steel plate and the amount of wear (depth) ΔCw of the roll, and the pressing force of this grinding wheel is taken into consideration in consideration of the width of the grinding wheel 6. A change start point and a change end point of P, and a decrease pattern or an increase pattern (for example, a pattern as shown in FIG. 5) of the pressing force between the start point and the end point are calculated, and the grinding wheel 6 of the grinding devices 4a and 4b is operated. This can be done by controlling the pressing control mechanism. Also, the pressing force change point has a function that can be designated by an arbitrary input.

Here, the wear amount (depth) ΔCw of the upper work roll 1o and the inclined wear start point may be measured, but, for example, using a statistical calculation method based on the actual value, for example, a steel plate It can be obtained by wear calculation from the weight of the material, the thickness after rolling of the steel plate, the width, the material of the rolling roll, the roll diameter, the rolling reaction force, the bending force, etc., and the inclined wear starting point or width b that causes uneven contact of the grinding wheel, The one-sided contact width d of the grinding wheel in the inclined wear region can be calculated.

The pressing force reduction pattern is set in accordance with the width (area) of the grinding wheel, the set pressing force, the amount of wear, the inclination angle of the inclined wear region, etc., so as not to cause excessive reduction in grinding. When grinding from the non-wearing area side to the wear area side, if the width (area) of the grinding wheel is 40 mm, the set pressing force is 20 kg / mm ² , and the wear amount is 0.004 mm, the pressing force P is not 20 kg / from the set pressing force in the wear area
It is possible to prevent the occurrence of the excessive grinding phenomenon by gradually reducing it to 0 in mm ² .

When grinding from the worn region 1z side to the unweared region side 1x, the width (area) of the grinding wheel is 40 m.
m, set pressing force 20kg / mm ² , wear amount 0.004mm
In this case, the excessive grinding phenomenon can be prevented by gradually increasing the pressing force P from 0 to 20 kg / mm ² to the set pressing force in the unweared area.

In this way, grinding can be performed while suppressing the generation of concentrated loads due to uneven contact of the grinding wheel in the inclined wear region, and the roll profile due to the ground surface and the worn surface can be secured with high accuracy, It is possible to secure stable quality.

The grinding machine used for carrying out the present invention may be any one having a structure capable of controlling the pressing force of the grinding wheel against the roll, and is applied to the one shown as the above-mentioned embodiment example. Is not limited. Further, the shape of the grinding wheel is not limited to the disk-shaped body, and may be a roll shape, a belt shape, a rectangular shape or the like having a shape that causes a one-sided contact phenomenon in the inclined wear region of the roll. Therefore, it does not necessarily have to form a rotating body. The number of grinding devices (grinding heads) to be arranged is usually two in the axial direction for each roll, but if the grinding range is wide, three or four may be arranged.

[0027]

Example In the case of carrying out the present invention using an online grinding device as shown in FIG. 1 in the online grinding of the rolling rolls (work rolls) of a hot finish rolling mill for rolling steel plate (SS41), The results will be outlined together with the case of online grinding of the conventional example. In this example, grinding is performed from the non-wearing area side to the wearing area side.

(Implementation conditions) Rolling change conditions Steel plate width: changed from 600 mm to 2200 mm Rolling speed: 160 mm / min to 1600 mm / min Grinding conditions Grinding area Unwearing area 1x Inclined wear area 1t Wearing area 1z Wear amount (depth) ) △ Cw: 0.004mm Grinding wheel (Material: CBN system) Size Width: 40mm Rotation speed: 500rpm-1600rpm

The rolling roll obtained by on-line grinding according to the present invention has no excessive grinding at the inclined wear portion formed between the threaded portion and the non-threaded portion, and has a step at the boundary with the threaded portion. A good roll profile could be obtained by grinding once without any occurrence. Therefore, it is not necessary to re-grind to adjust the roll profile, and the grinding productivity can be stabilized at a high level. On the other hand, in the case of the conventional example in which the pressing force is constant and the online grinding is performed, a step is generated at the boundary with the worn portion of the strip due to excessive grinding, and a good roll profile cannot be obtained by one grinding. It was In this example, the same effect was obtained when grinding from the worn region side to the non-wear region side.

[0030]

According to the present invention, in the case of performing on-line grinding of the rolling rolls of the steel plate finishing rolling mill by the grinding device, the grinding stone of the grinding wheel at the inclined wear portion formed between the plate passing portion and the non-passing portion is By controlling the pressing force, it is possible to prevent excessive grinding in the inclined wear portion and obtain a predetermined roll profile with high accuracy and high productivity.

[Brief description of the drawings]

FIG. 1 is a side conceptual illustration showing an example of an on-line grinding apparatus for rolling rolls embodying the present invention.

FIG. 2 is a plane conceptual explanatory view showing an arrangement example of an on-line grinding device for rolling rolls embodying the present invention.

FIG. 3 is a side cross-sectional conceptual explanatory view showing an abrasion state of a rolling roll and an example of a grinding operation of a grinding head of a grinding device.

FIG. 4 is a side view conceptual explanatory view showing a change in a contact state with a grinding surface of a grinding wheel in a steel sheet non-passing portion and a steel sheet passing portion of a rolling roll.

FIG. 5 is a conceptual explanatory view showing an example of a control pattern of a grinding wheel pressing force between a steel sheet unpassed portion and a steel sheet passed portion of a rolling roll according to the present invention.

FIG. 6 is a conceptual explanatory view showing an example of a pressing force control method for a grinding wheel according to the present invention.

FIG. 7 is a side conceptual explanatory view showing an example of a conventional roll online grinding apparatus.

[Explanation of symbols]

 1o Upper work roll 1u Lower work roll 1f Worn flat surface 1h Grinding flat surface 1x Unworn area 1a Unworn flat surface 1t Inclined wear area 1z Wear area 1s Axis 2o, 2u Backup roll 3 Rolling material 3s Steel plate 4a, 4b Grinding machine 5 Reinforcement disk 6 Grinding wheels 7a, 7b Grinding head 8 Traverse rail 9 Roll chock

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Kimura 1 Nishinosu, Oita City, Oita Prefecture New Nippon Steel Co., Ltd. Oita Steel Co., Ltd.

Claims (2)

[Claims] 1. An online grinding method for a rolling roll in a steel sheet rolling machine, wherein a roll grinding device is provided between rolling stands of the steel sheet rolling machine to grind the rolling roll online. When grinding toward the wear flat surface via the, the pressing force of the grinding wheel,
Online of rolling rolls in a steel plate rolling machine characterized by gradually grinding from the boundary between an unworn flat surface and a slanted wear surface to the boundary between a slanted wear surface and a worn flat surface while gradually reducing to a predetermined pressing force on the worn flat surface Grinding method. 2. An online grinding method for a rolling roll in a steel plate rolling machine, wherein a roll grinding device is provided between rolling stands of the steel plate rolling machine to grind the rolling roll online. When grinding toward an unworn flat surface after that, the pressing force of the grinding wheel,
From the boundary between the worn flat surface and the slanted wear surface to the boundary between the slanted wear surface and the unworn flat surface, the rolling roll in the steel plate rolling machine is characterized by gradually increasing the grinding force to a predetermined pressing force on the unworn flat surface. Online grinding method.