JP3728395B2 - Online roll grinding method - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an on-line roll grinding method, and more particularly to an on-line roll grinding method suitable for application when grinding the surface of a work roll included in a hot finish rolling mill.
[0002]
[Prior art]
FIG. 5 shows a schematic configuration of a general hot rolling line. In such a rolling line, a material to be rolled (slab) B preheated in a heating furnace is roughly rolled by a group of rough rolling machines indicated by R1 to R3. Then, after forming the plate-shaped material to be rolled S, it is rolled into a strip of a predetermined size by a finishing mill group indicated by F1 to F7, and the strip is wound by a winding device (downcoiler) indicated by DC1 or DC2. Has been done.
[0003]
Conventionally, as shown in this figure, in the hot rolling line, as the work roll of the finish rolling mill wears as the material to be rolled is rolled intermittently, the wear progresses to some extent. The operation mode of exchanging with another work roll whose surface has been previously polished is adopted. In such a rolling operation, after replacing with a polished work roll, a group of materials to be rolled until the next replacement with a polished work roll is referred to as a rolling cycle. The number is usually several tens to at most one hundred.
[0004]
Drawing the image of the material constituting the rolling cycle as shown in FIG. 6, but before the on-line roll grinder to be described later appeared, when looking at the rolling cycle from the first to the final one, The material to be rolled Sm having the maximum width in the rolling cycle comes in the middle of the first half of the rolling cycle, and gradually becomes wider before the material to be rolled Sm having the maximum width. However, a rolling order width configuration called a so-called coffin schedule is usually employed in which the rolling order becomes gradually narrower thereafter. In this specification, the width of the material to be rolled means the width after rolling, that is, the rolling width.
[0005]
The reason why the width of the material to be rolled is gradually widened in the first half of the rolling cycle in this way is that the thermal expansion of the roll gradually increases in the width direction (axial direction for the roll) This is to make progress. In addition, the reason why the width gradually becomes narrower than the maximum width is that, after the previous roll change, the history of some rolled material, after the rolled material of the maximum width where the wear of the roll progresses, FIG. 7 shows an image of the relationship between the cross-sectional shape of the upper and lower work rolls and the material to be rolled thereby and the thickness direction distribution (profile) of the material to be rolled at the corner of the wear bottom RB of the roll. it takes widthwise edges, caused the thick portion of the rolled material called edge buildup EB, is to make it poor quality does not occur such crimped edge portion at the time of annealing performed after taking-out winding.
[0006]
By the way, if the rolling cycle is actually set to have the rolling width configuration of the coffin schedule as described above, the material to be rolled is still in the slab stage before being inserted into the heating furnace of the hot rolling line. It must be arranged in advance so that it is in that order, but this operation takes a lot of time and effort.
[0007]
In addition, arranging the material slabs in advance in the order as described above leads to the fact that dozens of material slabs to be rolled must be stored for many days, insufficient storage space, casting The problem was an increase in inventory assets, along with problems such as loss of heat energy due to subsequent complete cooling of the slab and delays in delivery.
[0008]
In view of this, an on-line roll grinder has been developed in order to alleviate or eliminate the restriction of the rolling order for the material to be rolled as described above and solve the various problems described above. FIG. 8 shows an outline of an example of the online roll grinder 10, and the two grinders 10 each have a pair of rotating grindstones 12. The rotating grindstone 12 is pressed against the surface of the work roll R to roll This is an apparatus for polishing the roll surface in the oscillated range based on the principle of oscillating in the axial direction. Here, the term “oscillate” includes not only reciprocal motion but also traversing only one path in one direction.
[0009]
Due to the development of this apparatus, for example, even if a rolling cycle is commanded in the rolling order in which a wide width and a narrow width are mixed as shown in the image of FIG. 9, the material to be rolled generates a quality defect such as the edge buildup. Without a problem, the above-mentioned problems such as an increase in the amount of tax on inventory assets can be solved.
[0010]
Each grinding company is currently researching and developing a grinding method that effectively uses an online roll grinder with such advantages, and is seeking a better method. For example, as one of them, in Japanese Patent Laid-Open No. 5-42310, when a rolled material having the same sheet width is repeatedly rolled, or when moving from a wide to a narrow rolled material, rolling is performed. There has been proposed a method of grinding the entire surface of a rolling roll including only a sheet passing portion of the material or a non-passing portion of the material to be rolled.
[0011]
FIG. 10 shows an image of the grinding method proposed in this publication using the relationship between the rotating grindstone 12 and the work roll R. In this method, as shown in FIG. 4A, in the rolling order in which the width of the own material S gradually becomes narrower, the wear bottom is shown as shown by hatching the equivalent width of the own material S. Between the cases where only the plate part of the material to be rolled that hits or the entire surface including the non-plate part (step) shown by hatching in FIG. The entire surface including the non-passage plate portion (step) shown by oblique lines in FIG. However, in the submitted drawings, the shaded area is blacked out due to the input.
[0012]
By the way, the grinding wheel used for the rotary grindstone 12 of the online roll grinder 10 is expensive because it is a special material, and it is extremely important to reduce the amount of reduction because it leads to improvement of the grinding wheel basic unit. It is.
[0013]
[Problems to be solved by the invention]
However, the conventional on-line roll grinding method proposed in the above publication is improved as compared with the case where step grinding and full surface grinding are always used together, but it is necessary to grind the roll surface or the entire roll surface of the entire plate section. Therefore, there is a problem that it does not necessarily lead to a sufficient improvement of the grinding wheel basic unit.
[0014]
The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide an online roll grinding method capable of greatly improving the grinding wheel basic unit when grinding a work roll online.
[0015]
[Means for Solving the Problems]
The present invention is an on-line roll grinding method in which a grindstone is pressed against the surface of a rotating work roll to grind the surface, and after the material to be rolled at the start of on-line roll grinding (hereinafter referred to as the own material), the following By grinding the roll surface substantially corresponding to the maximum width included in the planned rolling order until the roll change, to the roll surface of the through plate part, only the wear step , on the inner side of the maximum width, It has been solved.
[0016]
The present inventors pay attention to the fact that the grindstone decreases in proportion to the amount of grinding of the roll, and even if the amount of grinding of the roll is further reduced, quality defects such as edge build-up will not occur on the material to be rolled. As a result of intensive studies to develop a grinding method, the present invention has been conceived.
[0017]
That is, in the present invention, the following description will be made with reference to FIG. 1 corresponding to FIG. When the rolling material Sm having the maximum width is present in the rolling sequence up to the roll change (roll change), the roll surface corresponds to the plate portion substantially matching the maximum width A, and the maximum width The wear level difference Rg generated inside is polished. As shown in FIG. 1, when the rolled material Sm having the maximum width is immediately after the own material S, the roll surface corresponding to the plate portion substantially matching the width B of the own material S, and the maximum width Only the wear step Rg indicated by the hatched portion of AB corresponding to the width difference of the roll surface corresponding to the above-described sheet passing portion of the material to be rolled A is ground. In other words, the surface of the roll corresponding to the plate portion of the material to be rolled having the maximum width included in the planned rolling order up to the next roll replacement after the material to be rolled (own material) at the start of online roll grinding, About the inner side of the maximum width, only the wear step is ground to the roll surface of the through plate portion.
[0018]
When the grinding amount of the roll according to the present invention is compared with FIG. 10 in the case of the grinding method of the above publication, the roll surface corresponding to the plate portion of the rolled material Sm having the maximum width (hereinafter also simply referred to as the plate portion A). ) Since there is no need to grind the stepped portion Ro on the outer roll surface, the amount of grinding can be reduced, and the grinding wheel basic unit can be greatly improved. Incidentally, as shown in FIG. 2, if the number of rolling advances and the maximum width until roll change including the own material S is gradually narrowed, a step (shaded portion) within the maximum width is accordingly adjusted. Can be ground.
[0019]
In the case of the present invention, the step portions Ro at both ends of the roll outside the plate A of the rolled material having the maximum width until the next roll change after the own material are completely online until the roll change is performed. Since the grinding by the roll grinder 10 is not performed, when the roll gap is narrowed, the stepped portion Ro is contacted by the upper and lower rolls, and it does not mean that the desired thickness of the material to be rolled is not finished. However, as a result of detailed studies by the present inventors, it has become clear that this is not the case. That is, the thickness of the material to be rolled has a thickness of about 1 mm even at the thinnest final stand, whereas the work roll wear during the rolling cycle is 0.3 mm per side above or below even at the maximum wear bottom. Therefore, even if both the upper and lower sides are combined, it is only 0.6 mm. Therefore, even when the thinnest material to be rolled of about 1 mm is rolled at the wear bottom of the roll, the stepped portion Ro of the upper and lower rolls is in contact. Absent.
[0020]
In the above description, in FIG. 1, the material to be rolled Sm having the maximum width is located immediately after the own material S. However, the present invention is not limited to such a case, and between S and Sm. Further, one or more other rolled materials having a width smaller than Sm may be inserted, and even in this case, the grinding method as described above is applied in the same manner, that is, the width B of the own material S is always applied. By grinding the wear step Rg corresponding to the difference between the maximum width A and the maximum width A, it is possible to achieve the effect of preventing the occurrence of edge buildup.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
FIG. 3 shows a hot rolling line to which the online roll grinding method of one embodiment according to the present invention is applied. As shown in this figure, the present embodiment is shown in FIG. 8 in the rear four stands corresponding to F4 to F7 in the finishing mill group provided in the hot rolling line shown in FIG. This is applied to the line where the online roll grinder 10 is installed.
[0023]
In FIG. 4, the structural example of the roll grinding system suitable for implementing the grinding method of this embodiment is shown. In this roll grinding system, when the rolling order data (rolling cycle) of the material to be rolled is transmitted from the host computer 20 to the lower computer 22, the lower computer 22 rotates the rotation via the control device 24 based on the data. By controlling the grindstone 12, the rotating grindstone 12 oscillates only within a predetermined range and grinds only the target wear step Rg of the work roll R.
[0024]
The host computer 20 is connected to an order entry computer 26 for inputting and managing data related to the order based on the order from the customer via the in-house LAN. The customer order value is received.
[0025]
The host computer 20 further has a function of arranging a large number of materials to be rolled in order of rolling based on the received width data of the materials to be rolled. Specifically, when the operator arranges the materials to be rolled in the rolling order while looking at the screen, the host computer 20 applies the check logic to determine whether the order is acceptable. The operator is prompted to correct the rolling order of the material to be rolled through the display. Check logic used at that time is, for example, whether or not the width difference between two adjacent rolled materials is within mm, or in addition to the width, the plate thickness, finishing temperature, etc. are also within a predetermined range. What is determined based on whether or not there is, for example.
[0026]
When the lower computer 22 receives the material data to be rolled together with the rolling order data from the upper computer 20 for each material to be rolled, the lower computer 22 further includes a roll change position (order of the final material to be rolled) by the operator. Is entered. As a result, each time the own material is updated due to the progress of rolling based on these data, the subordinate computer 22 determines the maximum width from the own material (the material to be finished and rolled next) to the next roll change. Which material is to be rolled, and its maximum width (dimension). Based on the determination, the lower-order computer 22 gives the command value of the pressing force when pressing the grindstone 12 against the roll for each material to be rolled together with the maximum width until the next roll change (during the rolling cycle) and the width of the own material. The data is also output to the control device 24.
[0027]
When the control device 24 receives these pieces of information, the control device 24, in the case of FIG. 1, has the through plate portion A corresponding to the maximum width and the through plate portion B corresponding to the width of the own material. A command is transmitted to the mechanical device of the online roll grinder 10 so as to grind the roll surface portion (wear step) Rg corresponding to the difference. The mechanical device of the on-line roll grinder 10 that has received this grinding command is pressed against the roll by a pressing mechanism (not shown) and corresponds to the difference between the maximum width of the rolled material Sm and the width of the own material S as shown in FIG. Oscillate so as to grind the friction step Rg which is the roll surface portion to be ground. This grinding operation is performed during finish rolling of the own material S. The reason is that when the machine body of the on-line roll grinder 10 is pressed against the roll when the tip of the material to be rolled is caught or when the tail end is pulled out, there is a risk that the machine will be damaged due to the impact transmitted. Because there is.
[0028]
When the rolling cycle consisting of 100 low carbon steels was rolled by one cycle by the grinding method of the present embodiment described in detail above, the grinding wheel basic unit could be improved from the conventional 0.011 cc / ton to 0.008 cc / ton. .
[0029]
As described above, according to the present embodiment, when the work roll of the hot finish rolling mill is subjected to online grinding, the basic unit of the rotating grindstone included in the roll grinder can be greatly improved.
[0030]
Although the present invention has been specifically described above, the present invention is not limited to that shown in the above embodiment, and various modifications can be made without departing from the scope of the invention.
[0031]
For example, the specific configuration of the rolling line to which the online roll grinding method of the present invention can be applied is not limited to the hot rolling line shown in the embodiment.
[0032]
Further, the grinding of the wear level Rg on the roll surface is not limited to during the rolling of the own material but may be performed after the rolling of the own material.
[0033]
【The invention's effect】
As described above, according to the present invention, the basic unit of the grindstone when the work roll is ground online can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing the principle of a grinding method of the present invention. FIG. 2 is a conceptual diagram showing an example of a grinding method when the maximum width after the own material gradually decreases. FIG. 3 is a grinding method according to an embodiment of the present invention. Fig. 4 is a block diagram showing an outline of a roll grinding system applied to the embodiment. Fig. 5 is an image showing an outline of a conventional hot rolling line. Fig. 7 is an image diagram showing the rolling order of the coffin schedule of Fig. 7. Fig. 7 is an explanatory diagram showing the failure of edge buildup occurring in the material to be rolled. Fig. 8 is a schematic perspective view showing the overall configuration of the online roll grinder. Image diagram showing the order of rolling that can be handled by use [Fig. 10] Image diagram showing the characteristics of the conventional online roll grinding method
R ... work rolls Rg ... wear step 10 ... online role grinder 12 ... rotary grindstone 20 ... host computer 22 ... lower calculator 24 ... controller 26 ... Order over entry computer

Claims (2)

An online roll grinding method in which a grindstone is pressed against a surface of a rotating work roll to grind the surface,
Roll material that substantially coincides with the maximum width included in the planned rolling sequence from the material to be rolled at the start of online roll grinding to the next roll change , passing through only the wear step inside the maximum width. An on-line roll grinding method characterized by grinding to the roll surface of a part.   The online roll grinding method according to claim 1, wherein the wear step is ground during rolling of the material to be rolled at the start of the online roll grinding.

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