JPH11216506A - Roll grinding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll surface grinding equipment suitable for a hot rolling mill which can sufficiently remove grinding dust particles and dropped abrasive grains by means of a simple device. SOLUTION: This device is a roll grinding equipment 20 equipped with a grinding stone 22 to grind the surface of a mill roll 1 when hot rolling is done, and a fluid jetting nozzle 35 of a simple structure to remove the grins produced between the grinding stone 22 and the mill roll 1 at the time of grinding is also installed near the grinding stone 22. The jetted fluid, accompanied with the grains produced at the time of grinding, flows down the roll surface and joins the roll cooling water poured a lot to the surface of the hot rolling mill roll 1, and then is removed, together with the roll cooling water, from the roll surface by the existing wiper (dewatering plate) to prevent the roll cooling water from dropping onto the plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll grinding apparatus, and more particularly to a roll grinding apparatus suitable for online grinding of a hot rolling roll.

[0002]

2. Description of the Related Art When a steel slab is hot-rolled by a rolling mill, a fatigue layer is gradually generated on a roll surface of a rolling roll that comes into contact with a material to be rolled. The depth (thickness) of the fatigue layer from the roll surface increases as the rolling load (generally represented by a rolling amount, a rolling distance, or a product of both) increases.

[0003] When such a fatigue layer progresses, the roll surface is broken due to cracks formed in the fatigue layer, and if left untreated, the life of the rolling roll is shortened.
Further, when rolling is performed with the roll surface roughened by the cracks, it is transferred to the material to be rolled, so that it is difficult to always maintain stable product quality. Therefore, as a countermeasure, conventionally, a roll after rolling has been removed from the rolling mill and taken out to a roll shop that is offline, and the thickness of the fatigue layer determined based on the rolling amount or rolling distance of the rolling roll is used as a roll. The rolling roll, which has been removed by grinding with a grinder and from which the fatigue layer has been removed, has been used by being incorporated in a rolling mill again.

[0004] On the other hand, apart from the formation of the fatigue layer, mechanical wear occurs in a portion of the rolling roll that comes into contact with the material to be rolled. This abrasion also proceeds along with the rolling, and a step (abrasion step) is formed between the non-abraded portion that does not contact the material to be rolled,
The role profile changes. The range in which this wear step occurs is the range of the sheet width of the material to be rolled. In the actual rolling operation, the plate width range of the material to be rolled is, for example, 800 to
Since the width ranges from a narrow width to a wide width of 1500 mm, the range of wear also changes according to the sheet width of the material to be rolled. If a narrow material is rolled and then a wide material is rolled using a rolling roll having a wear step in the range of the plate width, a narrow wear portion that has already occurred and a non-wear portion outside the narrow width portion have already occurred. The roll profile including the step is transferred to a wide product, and a good product cannot be obtained. Therefore, in order to minimize the influence of the wear step caused by the rolling of a certain width on the next rolling having a different width, when rolling a plurality of widths, the rolling order should be as wide as possible. The operation is restricted to narrow materials. However, even if the rolling order is regulated, the wear step proceeds, and eventually reaches the limit. When the limit is exceeded, the rolling roll is removed from the rolling mill as in the case of the removal of the fatigue layer, and the roll profile is corrected by a roll grinder in an off-line roll shop to correct the deformation of the roll profile due to a wear step.

However, in recent years, in view of the fact that such a rolling order regulation hinders an improvement in productivity, an online roll grinding technique in which a roll grinding device (roll grinder) is arranged in a rolling mill has been put to practical use, and online roll grinding has been realized. Grinding is performed.

[0006] In the online roll grinding, the following two types of grinding are mainly performed. (1) Partial grinding for removing the wear step by grinding the outside of the threaded portion. (2) Full surface grinding in which all roll surfaces are ground to remove uneven flaws locally generated on the roll surface.

[0007] By the practical use of this on-line roll grinding technique, the above-mentioned regulation of the rolling order for the rolled material sheet width can be relaxed and the surface flaws of the rolled material caused by the unevenness flaws can be prevented. It can be expected to improve the production capacity and the quality of the hot rolled steel sheet to be manufactured.

[0008]

As described above, in the conventional online roll grinding apparatus, the roll profile is corrected by performing partial grinding and full-scale grinding of the rolling rolls online during rolling. The problem that the particles of the cutting powder of the rolling roll and the falling abrasive grains of the grinding wheel generated during grinding cannot be sufficiently removed and adhere to the roll surface or the surface of the material to be rolled, causing damage to those surfaces. There is. In order to solve this problem, it is equipped with a nozzle that sprays a cleaning liquid so as to form a liquid flow curtain toward the grinding section where the grinding wheel and the roll come in contact with each other in order to remove particles of the cutting powder and abrasive particles falling off the grinding wheel. Roll surface grinding device convenient for online roll grinding of hot rolling mill
It has been proposed in JP-A-334413.

However, in order to use this for on-line roll grinding of a cold rolling mill, the liquid (including particles of cutting powder and abrasive particles falling off) sprayed from a nozzle is scattered to form a material to be rolled. It is necessary not to be mixed into the surface or rolling oil. Therefore, as shown in FIG. 4, the grindstone 2 is surrounded by a head 11 having an opening 11a on the tip side where the grindstone 2 and the roll 1 come into contact with each other. Tip mouth 1 that forms an annular shape along
A nozzle 12 having a nozzle 2a formed therein is provided, and water for lubrication, cooling, and cleaning during grinding is jetted from a tip end port 12a of the nozzle, and the periphery of the whetstone 2 is prevented from leaking the water to the outside. A forcible discharge is carried out to a collecting device (not shown) by a discharge means such as a rotary wing 15 or a pump suction attached to the apparatus. As a result, the following problems arise.

The grinding wheel 2 is surrounded by a head 11 and a cleaning water injection nozzle 12 is annularly disposed inside the head 2, and a discharge means must be provided to prevent the cleaning water after the injection from leaking out of the head 11. Therefore, the device becomes too complicated.

If the pressure of the liquid supplied to the nozzle is increased in order to enhance the effect of removing the particles of the cutting powder and the dropped abrasive grains, the liquid leaks from the opening 11a of the head 11 to the outside. Can not.

The present invention has been made to solve such a conventional problem, and is suitable for a hot rolling mill capable of sufficiently removing particles of a cutting powder and abrasive grains falling off with a simple apparatus. It is an object to provide a simple roll surface grinding device.

[0013]

To achieve the above object, a roll surface grinding apparatus according to the present invention is a roll grinding apparatus provided with a grinding wheel for grinding the surface of a rolling roll during hot rolling. A fluid jet nozzle for removing particles generated between the grinding wheel and the rolling roll is provided near the grinding wheel.

Here, the pressure of the cleaning fluid supplied to the fluid jet nozzle can be at least 0.3 Mpa. According to the present invention, the fluid ejected from the fluid ejection nozzle disposed near the grinding wheel flows down the roll surface with particles generated between the grinding wheel and the rolling roll, and onto the rolling roll surface of hot rolling. Merges with a large amount of roll cooling water. After that, the existing wiper (water-draining plate) is used to prevent the roll cooling water from getting on the roll surface and is removed from the roll surface together with the roll cooling water. Therefore, the generated particles containing the washing fluid that has flowed down remain on the material to be rolled. There is no.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an embodiment of an online roll grinding device (online roll grinder) according to the present invention, and FIG. 2 is a layout diagram of the grinding device as viewed from the direction of arrows II-II.

First, the online roll grinder 2
In FIG. 1, a grinding wheel 2 for grinding the surface of a rolling roll (work roll) 1 of a rolling mill will be described.
2 is rotatably supported by a bearing box 25 via a bearing 23. A grinding wheel rotation motor 27 supported on a bearing box 26 via a bearing 24 is disposed coaxially with the grinding wheel 22. The drive shaft 29 of the grinding wheel 22 and the output shaft 30 of the grinding wheel rotating motor 27 are rotatably connected by a universal joint 28 with splines. The bearing box 25 on the grinding wheel 22 side is connected to the gantry 3 via the linear guide 3l.
3, and moves back and forth in the axial direction while being guided by the linear guide 31 by the operation of the pressing cylinder 32. By the forward movement, the grinding wheel 22 is pressed against the rolling roll 1. Other than the grinding wheel 22 in the above configuration, it is covered with a cover 34 mounted on a gantry 33. The gap between the drive shaft 29 of the grinding wheel 22 protruding from the cover 34 and the opening of the cover 34 is closed by a seal 34a.

The operation of the pressing cylinder 32 and the grindstone rotation motor 27 is controlled by a command from a drive control device (not shown). Also, the gantry 33 can be moved along the axial direction of the rolling roll 1 by a driving device (not shown) that operates according to a command from the driving control device.

FIG. 2 shows an example of a so-called two-head type in which two grinding wheels 22 of the above-mentioned on-line roll grinder 20 are arranged at an interval in the axial direction of the rolling roll 1. Grind by sharing in the direction.
In the vicinity of the grinding wheel 22 exposed to the outside, particles generated when the rolling roll 1 is ground by the grinding wheel 22,
That is, the fluid ejection nozzles 35 for removing the particles of the cutting powder and the dropped abrasive grains are provided so as to be interlocked with the movement of the grindstone 22. The fluid ejection nozzle 35 is connected to a fluid supply device (not shown). The injection port 35a is
A simple type in which a fluid (for example, water) is sprayed from substantially one direction toward a contact portion between the rolling roll 1 and the grinding wheel 22 may be used.

Next, the operation will be described. Rolling is started, and online grinding by the online roll grinder 20 is started every time the rolling distance reaches a preset rolling distance. That is, a command is sent from the drive control device to the drive device of the gantry 33, the gantry 33 of the online roll grinder 20 moves, and the grinding wheel 22 moves from its standby position toward the surface of the rolling roll 1. When the grinding wheel 22 reaches a preset position, the grinding wheel rotation motor 27 is driven, and the grinding wheel 22 starts rotating.

Subsequently, the grinding wheel 22 is pressed against the surface of the roll 1 by the operation of the pressing cylinder 32, and the grinding of the surface of the roll 1 by the grinding wheel 22 starts. At the same time, the supply of the fluid to the fluid ejection nozzle 35 from a fluid supply device (not shown) is started, and the fluid is ejected from the ejection port 35a toward the contact portion between the rolling roll 1 and the grinding wheel 22, and lubrication, cooling, and Washing and removal of cutting powder and falling abrasive grains are performed. The injected fluid flows down the surface of the rolling roll 1 together with the removed cutting powder and particles of the dropped abrasive grains. In that case, especially when the particles that flow down the surface of the upper rolling roll fall on the material to be rolled and are rolled while adhering to the surface of the material to be rolled, concave defects occur and product quality is impaired. However, in the case of hot rolling, a large amount of roll cooling water is injected into the surface of the rolling roll 1, and the injected fluid merges with the roll cooling water. The rolling roll 1 of the hot rolling is usually provided with a wiper (draining plate) for preventing the roll cooling water flowing down the roll surface from riding on the roll, and the cleaning fluid joined to the roll cooling water. Both are removed from the roll surface by the wiper before reaching the surface of the material to be rolled. Therefore, particles such as abrasives entrained in the jet fluid do not remain on the material to be rolled.

The grinding wheel 22 comes into contact with the surface of the rolling roll 1 and performs grinding while moving along the roll axis along with the movement of the gantry 33. During that time, as described above, the cutting powder and the particles of the dropped abrasive grains are removed by the fluid ejection of the fluid ejection nozzle 35. When the predetermined amount of grinding is completed,
The pressing cylinder 32 operates in the retreating direction, and the grinding wheel 22 and the fluid jet nozzle 35 retreat. Thereafter, the grinding wheel 22 and the fluid jet nozzle 35 move to the standby position together with the gantry 33 to prepare for the next grinding.

FIG. 3 shows the ratio of the occurrence of dents due to particles on the rolled product surface in the above embodiment (rate of occurrence of dents = number of coils generating flaws / number of rolling coils) and the fluid pressure of the fluid injection nozzle 35. (MPa) is shown. From FIG. 3, the fluid pressure is 0.1,
As the pressure increases to 0.2 and 0.3 MPa, the rate of occurrence of the dents sharply decreases. It can be seen that the flaw occurrence rate is 0. from now on,
The fluid pressure of the fluid ejection nozzle 35 in the present invention is preferably at least 0.3 MPa, and preferably 0.4 M
It can be said that it is Pa or more.

In the above embodiment, the grinding wheel 22
Is shown in the case of a two-head type in which two are arranged for one rolling roll. However, the present invention is not limited to the number of the grinding wheels 22 and the operation thereof.

The configuration of the online roll grinder 20 is not limited to the one shown in FIG.

[0025]

As described above, according to the roll grinding apparatus of the present invention, when grinding the surface of the roll during hot rolling, leakage of the injected fluid is considered in the vicinity of the grinding wheel. By providing a fluid injection nozzle having a simple structure that does not need to be provided, there is an effect that particles generated during grinding can be almost completely and extremely easily removed.

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment of a roll grinding device according to the present invention.

FIG. 2 is a layout diagram of a grinding wheel shown in the direction of arrows II-II in FIG.

FIG. 3 is a graph showing the generated particle removing effect of the roll grinding device according to the present invention.

FIG. 4 is a schematic view of a conventional roll surface grinding device.

[Explanation of symbols]

 1 Roll Roll 20 Roll Grinding Device 22 Grinding Wheel 35 Fluid Injection Nozzle

Continued on the front page (72) Inventor Kenji Matsumura 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside Kawasaki Steel Works Chiba Works (72) Inventor Hiroshi Narumi 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Corporation Company Chiba Works

Claims (1)

[Claims] 1. A roll grinding apparatus provided with a grinding wheel for grinding the surface of a rolling roll during hot rolling, wherein a fluid for removing particles generated between the grinding wheel and the rolling roll is provided near the grinding wheel. A roll grinding device having an injection nozzle.