JPS58223556A - Grinding of roll - Google Patents

Abstract

PURPOSE:To shape a roll to be ground to an arbitrary roll crown easily and with high accuracy by varying the pressing force to the roll to be ground by curving the pressing surface of a contact roll, in the rolling grinding of the roll to be ground. CONSTITUTION:The roll to be ground is ground by a roll grinding apparatus as follows: A table 11 is transferred to a roll 10 to be ground by a feed mechanism 12, and a rolling grinding belt 9 is brought into contact with the roll 10. At this time, a contact roll which presses the belt 9 onto the roll 10 is curved by bending apparatuses 2a and 2b. Since said roll is curved outward, the pressing force for the roll 10 is large at the both edges and small at the center part. Therefore, the amount of cut to the roll 10 is shallow at the center and deep in the vicinity of the edges. According to the above method, the roll 10 can be shaped to an arbitrary roll crown easily and with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roll grinding method for corrective grinding of a work roll of a hot rolling mill or the like.

In a hot rolling mill, the work rolls come into contact with the steel plate, so the contact portion gradually wears out.

Therefore, the following problems occur.

1) Steel plate accuracy deteriorates due to roll wear, and rolling efficiency decreases when the rolls are removed and corrective grinding is performed to prevent this deterioration of steel plate accuracy.

2) If o-ru milling is left unattended, the rolled wheels must be ordered from wide to narrow, making it difficult to perform rolling in accordance with demand.

As a method for eliminating the problems 1) and 2) above, an online grinding method has been devised as follows, in which correction grinding is performed with the roll attached.

■ Grinding method in which a fixed piece of whetstone is pressed against a roll (
(Japanese Patent Publication No. 14010/1983). With a fixed type whetstone, the cutting quality is likely to deteriorate due to the grindstone's lip jamming, and the precision due to uneven wear of the whetstone is likely to occur, so dressing of the whetstone is required frequently. Furthermore, during grinding, the grinding surface of the grinding wheel is always in contact with the roll, so dressing cannot be performed, and for dressing, grinding must be interrupted and the grinding wheel must be moved to a position where dressing can be performed, resulting in low grinding efficiency.

■ A method of grinding by moving a forcibly rotating whetstone in the direction of the n-ru axis (Japanese Patent Laid-Open No. 131554/1983). Since this method uses a forcedly rotating grindstone, it is more efficient and easier to dress than the fixed grindstone type. However, in this method, grinding is carried out by moving a narrow-width whetstone in the four-wheel axis direction relative to the roll, so in order to obtain the desired roll accuracy, a short precision grindstone feeding mechanism is required, but In inter-rolling mills, it is difficult to implement such a grinding wheel feeding mechanism due to thermal deformation and vibration surface disturbances, resulting in insufficient roll accuracy.

■ Grinding method using a grinding belt (Japanese Patent Laid-Open No. 56-3
No. 3108). This method uses a grinding belt, so the grinding efficiency is higher than the above two methods, but the rolls that can be ground are limited to cylindrical ones, and it is not possible to grind grinders with arbitrary roll crowns, such as a bulge in the center. Therefore, it lacked versatility.

The present invention aims to provide a roll grinding method that further improves the method using a grinding belt described in (1) above and can easily form an arbitrary roll crown with high precision. In a method of commercially grinding a roll to be ground by pressing a contact roll on which a belt is stretched, the roll to be ground is commercially ground, by curving the pressing surface of the contact roll and changing the pressing force against the roll to be ground. It is characterized by being formed into any roll crown.

Hereinafter, the roll grinding method of the present invention will be explained in detail based on examples.

The roll grinding method of the present invention is a type of method in which the roll to be ground is ground by a grinding belt, but instead of pressing the contact roll with the grinding belt stretched over it as it is, the contact roll is Grinding is performed by pressing the roll against the roll to be ground while curving it along the contour to be formed on the roll to be ground. For example, if the contact roll is curved outward by increasing the pressing force applied to both ends of the contact roll, the roll to be ground will only receive a small grinding pressure toward the center and will be ground to a larger diameter. The grinding roll is formed into a barrel shape. As described above, in the present invention, any desired roll crown can be formed on the ground roll 1 by curving the contact roll and adjusting the amount of curvature.

Next, an example of an apparatus for implementing the roll grinding method of the present invention will be described.

Figures 1 (a) and (b) and 2 show the daily grinding machine. As shown in the figure, a table 11 is installed on the bed 1, and the table 11 is movable toward and away from the roll to be ground 10 by a feeding mechanism 12. A grinding heald 9 for grinding the roll to be ground 10 is stretched between the contact rolls 41 and the dynamic rolls 8 on the table 11. The contact roll 4 is provided parallel to the roll to be ground 10 and is rotatably attached to the shaft 3. The contact roll 4 is divided into a plurality of parts in the axial direction, and the shaft 3 passes through them with a clearance between them, so the shaft 3 and the contact roll 4 can be easily bent. , rotates smoothly even when curved.

The shaft 3 is supported at both ends by bending devices 2a and 2b fixed to a table 11, and a control device 13 is connected to the bending devices 2a and 2b. Curvature is controlled.

Further, the grinding belt 9 stretched over the contact roll 4 is divided into a plurality of belts for each roll in correspondence with the contact roll 4 being divided into a plurality of belts in the axial direction. Even if the entire four wheel 4 is curved, the grinding belt 9 is made more compact and less likely to loosen.

On the other hand, a drive roll 8 that tensions the grinding belt 9 on the other side.
is attached to a shaft 7, one end of which is supported by a bearing 6, and the other end connected to a motor 5. Therefore, when the motor 5 is operated, the shaft 7 and the drive roll 8 rotate, and the grinding belt 9 rotates in an annular manner.

The roll grinding device having the above configuration grinds the roll to be ground 10 in the following manner.

First, the motor 5 is operated to rotate the grinding belt 9. The table 11 is moved by the feed mechanism 12 and the roll 10 to be ground is
The rotating grinding belt 9 is brought into contact with the roll 10 to be ground. At this time, the contact four 4 that presses the grinding belt 9 against the roll to be ground 10 is bent by the bending devices 2a, 2b (see FIG. 2). In FIG. 2, since the contact roll 4 is curved outward, the pressing force against the row to be ground 1uncf' is large at both ends and small at the center. Therefore, the amount of cut received by the roll to be ground 10 is shallow at the center and becomes deeper toward the edges. As a result, the roll to be ground 101it is formed into a barrel shape with a large diameter at the center and a small diameter at the ends. Since the shape formed on the roll to be ground 10, that is, the roll crown, depends on the degree of curvature of the contact roll 4, the control device 13 that controls the degree of curvature of the contact roll 4 is controlled via the bending devices 2a and 2b. By operating it, it is possible to form any desired roll crown on the roll to be ground 10.

Note that since the grinding belt 9 is divided into a plurality of parts in the width direction, if there is a gap between these parts, there is a risk that the seal 10 to be ground will be left uncut in this part. If the shaft 7 is ground while being moved somewhat in the axial direction, such a problem of leaving uncut marks will not occur.

Finally, as specifically explained based on the examples, according to the method example of the present invention, any desired roll crown can be easily and accurately formed on the roll to be ground.

[Brief explanation of the drawing]

Figures 1 (a), (b) and 2 show an apparatus for carrying out the roll grinding method of the present invention, Figure 1 (a) is a front view of the apparatus, and Figure 1 (6) shows the apparatus. FIG. 2 is a partial front view of the device. In the drawing, 1 is a bed, 2a and 2b are bending devices, 3.7 is a shaft, 4 is a contact roll, 5 is a motor, 6 is a bearing, 8 is a drive roll, 9 is a grinding belt, 10 is a roll to be ground, 11 is a table, 12 is a feeding mechanism, and 13 is a control device. Patent applicant Mitsubishi Heavy Industries, Ltd. Patent attorney Shibe Mitsuishi (and 1 other person) Figure 1 (a)
(b) O 1%: ( ■ Figure 2!/+1

Claims (1)

[Claims] A roll grinding method characterized in that the pressing surface of the contact roll is curved and the pressing force against the roll to be ground is varied to form the roll to be ground into an arbitrary roll crown.