JPH0825142B2 - Short fiber reinforced grindstone for online roll grinding - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of an on-line roll grinding wheel for grinding the outer peripheral surface of a roll online.

BACKGROUND ART For example, in a work roll of a rolling mill that rolls a material to be rolled such as a steel plate or a steel ingot, a portion corresponding to a side edge of the material to be rolled is locally roughened at a contact portion with the material to be rolled. Uneven wear. Further, similar uneven wear and the like also occur in other rolls such as a backup roll that backs up the work roll. Therefore, it is necessary to regrind the outer peripheral surface of those rolls, but as one of the means, the grindstone is moved along with the rotation of the roll while the tip surface of the grindstone is pressed against the outer peripheral surface of the roll. By rotating or forcibly rotating the grindstone separately from the roll by a drive motor etc., sliding friction is generated between the tip surface and the outer peripheral surface of the roll, and the roll is placed in the stand of the rolling mill. It has been proposed to grind as-built, ie online. For example,
61-140312, JP-A-61-154706, JP-A-62
The grinding device and method described in JP-A-127109 and the like are one example thereof. For example, in the grinding device of JP-A-62-127109, the tapered tip surface is on the outer peripheral surface of the roll and the rotary shaft of the roll. With the pressure offset from the heart,
Sliding friction is generated between the roll outer peripheral surface and the roll outer peripheral surface is grinded online. By doing so, compared with the case where the rolls are individually removed and ground, the rolling mill Improves operating rate. Incidentally, in the above-mentioned JP-A-61-140312 and JP-A-61-154706, there is a type in which a grindstone is rotated together with the rotation of a roll, and in JP-A-62-127109. Discloses a type in which a grindstone is forcibly rotated by a drive motor. Further, such an online grinding is usually performed while a plurality of grindstones are arranged apart from each other in the axial direction of the roll, and these grindstones are respectively oscillated in the axial direction of the roll. .

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, when an attempt is made to grind a roll online as described above, the vibration of the roll accompanying rolling, or unevenness such as a step or a protrusion generated on the outer peripheral surface of the roll due to the uneven wear is generated. There was a problem that damage such as chipping (breakage) or cracking would occur at the corners of the peripheral edge of the tip surface of the grindstone due to such collisions. This is particularly noticeable in a vitrified grindstone having a high elastic modulus, but also in a resinoid grindstone using a phenol resin, epoxy resin, polyvinyl alcohol resin or the like as a binder, or a rubber grindstone using natural rubber or synthetic rubber as a binder. It was a problem as well.

The present invention has been made in view of the above circumstances, and an object thereof is to easily damage a roll of a rolling mill or other processing machine having a step or a protrusion on the outer peripheral surface even if the roll is ground. It is to provide a whetstone without.

Means for Solving the Problems In order to achieve the above object, the present invention provides a tapered outer peripheral surface of a roll in a state where the tapered distal end surface is pressed against the outer peripheral surface of the roll by being offset from the rotational axis of the roll. A grindstone that grinds the outer peripheral surface of the roll online by generating sliding friction with the surface,
It is characterized in that short fibers bundled into 50 to 500 bundles each having a length of mm are uniformly mixed.

Action and effect of the invention In such a short fiber reinforced grindstone, since the short fibers in a bundle of 50 to 500 pieces with a length of 1 to 10 mm are uniformly mixed, their mechanical properties are Improves and prevents the occurrence of damage such as chipping and cracking in spite of the vibration of the roll and the collision with the irregularities existing on the outer peripheral surface of the roll, and the thermal expansion of the short fibers is greater than that of the binder. When it is small, the deformation due to the thermal expansion is also suppressed.
Further, by increasing the tenacity and the rigidity, the contact area with the roll is reduced and the grinding performance is improved.

Further, in the present invention, one having a length of 1 to 10 mm is 50 to 500.
Since short fibers bundled into individual pieces are used, their dispersibility is higher than that of long fibers, and moreover, the chipping resistance and grinding performance of the grindstone can be made compatible, and the mechanical properties are improved. Since it can be improved uniformly, and the mechanical properties thereof do not have directionality, the occurrence of damage such as chipping is more effectively prevented. The fiber length of 1 to 10 mm means that if it exceeds 10 mm, it becomes cotton-like when mixed and it becomes difficult to uniformly disperse, and the mechanical properties are directional, while if it is shorter than 1 mm, it becomes uniform. This is because although it is excellent, it does not have sufficient impact resistance. In addition, it is better to mix 50 to 500 pieces in a bundle than to put them in pieces one by one, because it has better workability and uniform dispersibility, and the number of fibers required to obtain the desired strength can be easily and uniformly obtained. This is because they can be mixed.

Also, as a binder, phenol resin, epoxy resin,
When the present invention is applied to a zinoid grindstone using a polyvinyl alcohol resin and a rubber grindstone using a natural rubber or a synthetic rubber, it is possible to obtain impact resistance superior to that of a vitrified grindstone using an inorganic binder.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a short fiber reinforced grindstone for online roll grinding (hereinafter, simply referred to as grindstone) 10 which is an embodiment of the present invention. This grindstone 10 is for grinding a roll of a hot rolling mill online, and has a cylindrical shape, and its tip face 12 is at an angle θ from a plane perpendicular to the axis as it goes to the outer peripheral side. The taper surface is inclined toward the rear end side, and its outer peripheral corner portion is chamfered into an R shape having a radius of curvature of about 5 mm. Also, this grindstone 10
Is a resinoid grindstone in which abrasive grains such as Al ₂ O ₃ , SiC, and CBN are bonded with an epoxy resin binder, for example, GC220J8BY, WA220J8BY
(JIS standard), CBNC220J100BY (outlet 100), etc., and the short fibers of glass fiber are mixed evenly inside. This short fiber has a diameter
A bundle of 50 to 500, preferably 100 to 200, glass fibers of about 10 μm, the length of which is 1 to 10
mm, preferably about 3-5 mm.

Further, a nut 14 is embedded in the back surface of the grindstone 10, and the bolt 20 is tightened through a mounting flange 18 fixed to the tip of the shaft 16, so that the grindstone
10 is rotatably supported by a bearing device (not shown) and is used for roll grinding of a rolling mill. 2 to 4 are conceptual views for explaining an example of online grinding of a roll by the grindstone 10, and are a front view, a right side view and a plan view, respectively.
Hereinafter, an example of an online method for grinding a roll of a rolling mill will be described with reference to these drawings.

2 to 4, reference numeral 30 denotes a work roll which is disposed substantially horizontally on a hot rolling mill (not shown) and is driven to rotate about a rotation axis l, and the grindstone 10 has a rotation axis m It is offset downward by a dimension s with respect to the rotation axis l, and is arranged in a posture inclined by an angle φ with respect to a plane n perpendicular to the rotation axis l. Whetstone 10
Is rotatably supported about a rotation axis m through a shaft 16, and is provided with a tip end surface 12 by a pressing means (not shown).
Is pressed against the outer peripheral surface of the work roll 30 during hot rolling, so that the work roll 30 is rotated in the counterclockwise direction indicated by the arrow in FIG. 30 axial direction, that is, FIG. 2,
It is reciprocated (oscillated) in the left-right direction in FIG. At this time, the grindstone 10 is rotated at a peripheral speed of, for example, 400 to 1000 m / min, and the moving direction and the moving speed of each part of the tip surface 12 of the grindstone 10 are the moving direction and the moving speed of the outer peripheral surface of the work roll 30. Therefore, sliding friction occurs at these contact portions, and the outer peripheral surface of the work roll 30 is ground. In addition, in actual roll grinding, such a grindstone 10
Are usually arranged in the axial direction of the work roll 30 at regular intervals. The angle φ is substantially the same as the angle θ, and is set to about 0.5 ° to 1 ° in this embodiment.

Here, when the grindstone 10 is pressed against the outer peripheral surface of the work roll 30 during hot rolling as described above, the grindstone 10 is subjected to the vibration of the work roll 30 and the collision with the irregularities formed on the surface of the grindstone 10. A relatively large impact is applied. Further, in the above-mentioned use mode, the sliding friction causes tensile stress to act on the outer peripheral side portion of the tip surface 12 of the grindstone 10 and compressive stress to act on the inner peripheral side portion thereof. Therefore, conventionally, there has been a problem that chipping, cracking and the like are likely to occur at the outer peripheral edge portion of the tip surface 12 to which the tensile stress is applied.

On the other hand, the grindstone 10 of the present embodiment, since the short fibers of the glass fiber are uniformly mixed, its mechanical properties are improved, such as vibration of the work roll 30 and collision with irregularities present on the outer peripheral surface, etc. Regardless of this, damage such as chipping and cracking is prevented, and deformation due to thermal expansion is also suppressed. Further, by increasing the tenacity and the rigidity, the contact area with the work roll 30 is reduced, and the grinding performance is improved.

On the other hand, since short fibers are used in this way, its dispersibility is higher than that of long fibers, and it is easy to uniformly disperse the short fibers in the mixture of the abrasive grains and the binder at the time of production. The mechanical properties of 10 can be improved uniformly, and since the mechanical properties do not have directionality,
The occurrence of damage such as chipping is more effectively prevented. In particular, in this embodiment, since a bundle of 50 to 500 glass fibers each having a length of 1 to 10 mm is used, workability and its uniform dispersibility are excellent, and the machine of the grindstone 10 is used. Properties are greatly improved.

Further, since the above-mentioned grindstone 10 is composed of a resinoid grindstone with an epoxy resin binder, it is possible to obtain more excellent impact resistance performance than a vitrifiber grindstone with an inorganic binder such as feldspar, porcelain stone, and refractory clay. Even if the work roll 30 vibrates, the finished surface roughness is maintained at a constant quality due to shock absorption.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, the nut 14 is directly embedded in the grindstone 10, but like the grindstone 40 shown in FIG.
It is also possible to separate the whetstone body 42 and the backing plate 44 and embed the nut 14 in the backing plate 44. In this case, the whetstone main body 42 is configured in exactly the same manner as the whetstone 10, while the backing plate 44 is made of, for example, Al ₂ O.
It is composed of a filler such as ₃ , SiC, CBN, etc. hardened with a phenol resin, and the grindstone body 42 may be molded and hardened on the backing plate 44 thereof and fixed at the same time. The material of the backing plate 44 and the means for fixing the backing plate 44 and the grindstone body 42 can be changed as appropriate.

In the above embodiment, the grindstone 10 is offset with respect to the rotation axis l of the work roll 30 and is pressed against the outer peripheral surface of the work roll 30 in a posture inclined with respect to the plane n.
The usage mode in which grinding is performed so that the work roll 30 can be rotated along with the rotation has been described, but the attitude of the grindstone 10 is changed, and the grindstone 10 is connected to a drive motor, a brake device, or the like to be forcedly rotated. The grindstone 10 of the present embodiment can be used in various modes, such as by applying or applying a braking force.

Further, in the above-mentioned embodiment, the resinoid grindstone having the epoxy resin as the binder is mixed with the short fibers of the glass fiber, but the resinoid grindstone having the phenol resin or the polyvinyl alcohol resin as the binder, the natural rubber or the synthetic rubber is bonded. It is also possible to use a rubber grindstone or the like as the agent or to mix short fibers such as carbon fiber and Al ₂ O ₃ fiber.

Further, in the above embodiment, the case where the work roll 30 of the hot rolling mill is grinded online has been described, but the grindstones 10 and 40 are used for online grinding of other rolls such as a backup roll that backs up the work roll 40. Of course, the present invention can also be applied to a grindstone for grinding rolls of other processing machines including a cold rolling mill.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a short fiber reinforced grindstone for online roll grinding which is an embodiment of the present invention. 2 to 4 are conceptual views for explaining an example of usage of the grindstone of FIG. 1, FIG. 2 is a front view, FIG. 3 is a right side view, and FIG. 4 is a plan view. Is. FIG. 5 is a vertical sectional view showing another embodiment of the present invention. 10,40: Short fiber reinforced grindstone 12: Tip surface, 30: Work roll

Front page continued (72) Inventor Kanji Hayashi 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Works (72) Inventor Takayuki Goto, 1-8, Sachiura, Kanazawa-ku, Yokohama, Kanagawa Prefecture 1 Mitsubishi Heavy Industries, Ltd. Basic Technology Research Institute (72) Inventor Hisao Matsushima 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Works

Claims (1)

[Claims] 1. A sliding friction is generated between an outer peripheral surface of the roll and the outer peripheral surface of the roll in a state of being pressed against the outer peripheral surface of the roll by being offset from the rotational axis of the roll. A grindstone for grinding the outer peripheral surface of the roll online, characterized in that short fibers in a bundle of 50 to 500 pieces each having a length of 1 to 10 mm are uniformly mixed, for online roll grinding Short fiber reinforced grindstone.