JPH0532126B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a grinding method for grinding the outer circumferential surface of a rotating object, particularly for online grinding of work rolls of rolling mills such as cold or hot rolling mills. It is suitable for use in

<Conventional technology> In hot rolling mills that roll steel plates, etc., the wear of work rolls during rolling is much greater than that of back-up rolls, and especially the skin of the work roll's threaded portion where the strip comes into contact with the wear of the work rolls. This is severe, and there is a tendency for local wear to be large in the parts corresponding to the side edges of the strip.
For this reason, when rolling strips, the rolling order is scheduled to start with wide strips and then move to narrow strips, and the rolls are replaced periodically to remove worn rolls from the rolling mill. After being ground outside, it was taken back into the rolling mill for use.

By the way, in this method of performing scheduled rolling and grinding the rolls off-line, the rolling order is restricted, which hinders production efficiency, and the rolls must be replaced frequently, requiring a great deal of labor. , which was a major factor in the decline in equipment operating rates. Therefore, progress has been made in the development of an online grinding device that grinds the rolls during rolling while the rolls are still installed in the rolling mill, thereby extending the roll replacement cycle and making it possible to perform rolling operations without restrictions on the rolling order due to strip width. I came.

Conventionally known online grinding devices include those of the type shown in FIGS. 4a and 4b. That is, in the case shown in FIG. 4a, a prismatic block-shaped grindstone 1 is pressed against a rotating work roll 2 for grinding. In the case shown in FIG. 4b, a disc-shaped grindstone 3 is rotated by a motor (not shown) and is pressed against the surface of the rotating work roll 1 for grinding.

<Problems to be Solved by the Invention> In the case of using the prismatic block-shaped grindstone 1 shown in FIG. The grinding wheel 31 has the drawback that the grinding wheel 31 is easily clogged with grinding powder or seizes, and since the grinding wheel 1 is prismatic, its corners are chipped, resulting in a short service life and a tendency to cause accidents.

On the other hand, in the case of using the disc-shaped grindstone 3 shown in FIG. 4b, the life of the grindstone 3 is long and the grinding performance is good. It is necessary to rotate it with a motor (not shown). Therefore, a large space is required in the longitudinal direction of the roll, and when a plurality of grinding wheels 3 are arranged, the distance between adjacent grinding wheels 3 must be set large, and the distance in the longitudinal direction of the roll is The disadvantage is that it becomes impossible to grind the entire surface along the .

In view of the above-mentioned drawbacks of the conventional online grinding apparatus, it is an object of the present invention to provide an online grinding method with a simple structure, low cost, and excellent grinding ability.

<Means for Solving the Problems> The rotary body grinding device of the present invention grinds the outer circumferential surface of the cylindrical workpiece by pressing a rotatably supported grindstone against the rotating cylindrical workpiece. At this time, an offset is set so that the extension of the rotational axis of the grindstone does not intersect with the rotational axis of the cylindrical workpiece, and the rotational axis of this grindstone is set in a plane perpendicular to the rotational axis of the cylindrical workpiece. The outer circumferential surface of the cylindrical object to be ground is ground by the slip that occurs at the contact point between the outer periphery of the cylindrical object and the grindstone. That is.

<Function> Since the rotation axis of the grindstone is offset from the rotation axis of the cylindrical workpiece and is also inclined, the distance between the grindstone and the outer peripheral surface of the cylindrical workpiece that is driven and rotated is Sliding friction is generated, and the outer peripheral surface of the cylindrical object to be ground is automatically ground by this sliding friction.

<Example> FIG. 1 a shows the working concept of an example in which the rotating body grinding method of the present invention is applied to a rolling roll, and FIG. 1 a and FIG. As shown in FIG. 2 showing the planar shape, the grindstone 12 pressed against the outer peripheral surface of the rolling roll 11 has a cylindrical shape in this embodiment, and its rotation axis 13
It is rotatably supported on a support member (not shown) around the center. The rotational axis c of the grindstone 12 is offset by an amount a from the rotational axis C of the rolling roll 11, so that the extension of the rotational axis c does not intersect with the rotational axis C. Further, the rotational axis c of the grinding wheel 12 is inclined by α with respect to a plane (line) p perpendicular to the rotational axis C of the rolling roll 11, so that the outer circumferential surface of the rolling roll 11 and the grinding wheel 12 are not in contact with each other. point S
is a position that passes through the rotation axis c and is shifted by an angle θ with respect to a line L that is parallel to the rotation axis C.

Therefore, as shown in FIG. 3 showing the principle of rotation of the grinding wheel 12 according to this embodiment, the rolling roll 11 _is
When the grindstone 12 is driven and rotated at a circumferential speed of , the grindstone 12 rotates at _{V G =} V _R ·cosθ, where the rotation speed of the grindstone 12 is V G . At this time, if the component force in the direction of the rotational axis c at the contact point S is V _S , a slip of V _S occurs between the rolling roll 11 and the grinding wheel 12, but V _S = V _R・sinθ, and the support As a result of the member preventing displacement of the grinding wheel 12 in the V _S direction, the outer circumferential surface of the rolling roll 11 is ground by a frictional force corresponding to this sliding. In this case, the inclination angle α and offset amount a of the grindstone 12 may be adjusted so that θ becomes an optimal value based on the grinding efficiency of the grindstone 12, the degree of clogging, etc.

In this example, the case of grinding a rolling roll of a rolling mill was explained, but grinding of the outer peripheral surface of other cylindrical rotating bodies (for example, cylindrical objects such as work rolls, intermediate rolls, back-up rolls, etc.) It goes without saying that it can be widely applied to grinding.

<Effects of the Invention> According to the method for grinding a rotating body of the present invention, the grindstone is tilted and offset with respect to the rotating body to generate sliding wear between them, and the outer peripheral surface of the rotating body is ground by this sliding friction. This eliminates the need for a special grinding wheel drive source, making it possible to reduce equipment costs and save space.

[Brief explanation of the drawing]

FIG. 1a is a conceptual diagram of the working state of an embodiment of the rotating body grinding method according to the present invention, FIG. 1b is a sectional view taken along the line B-B, and FIG. 2 is a plan view of FIG. 1a. , FIG. 3 is a working principle diagram showing the grinding principle, and FIGS. 4 a and 4 b are working conceptual diagrams showing the conventional rolling roll grinding method. Further, in the reference numerals in the figure, 11 is the rolling roll, 12 is the grindstone, c is the rotational axis of the grindstone, C is the rotational axis of the rolling roll, a is the offset amount, α is the inclination angle, and p is the rotation of the rolling roll. A plane perpendicular to the axis, S is the contact point between the rolling roll and the grindstone, and θ is the contact angle.

Claims (1)

[Claims] 1. When grinding the outer peripheral surface of the cylindrical workpiece by pressing a rotatably supported grindstone against the rotating cylindrical workpiece, an extension of the rotational axis of the grindstone is The grindstone is offset so as not to intersect with the axis of rotation, and the axis of rotation of this grindstone is set to be inclined with respect to a plane perpendicular to the axis of rotation of the cylindrical object to be ground. A method for grinding a rotary body, characterized in that the outer circumferential surface of the cylindrical object to be ground is ground by slippage that occurs at a contact point between the outer circumferential surface and the grindstone.