JPH07108512B2 - Double structure grinding wheel for online roll grinding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a grindstone for grinding an outer peripheral surface of a roll online, and more particularly to improvement of a fixed portion of a double-structure grindstone with less damage such as chipping.

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 re-grind the outer peripheral surface of those rolls, as one means, by using a grindstone having a cylindrical shape, one end surface in the axial direction is used as a processing surface on the outer peripheral surface of the roll. In the pressed state, the grindstone is rotated along with the rotation of the roll, or by forcibly rotating the grindstone separately from the roll by a drive motor or the like, between the tip surface and the outer peripheral surface of the roll. It has been proposed to generate sliding friction and grind the roll as it is installed in the stand of the rolling mill, ie online. For example,
61-140312, JP-A-61-154706, JP-A-62
The grinding device and method described in Japanese Unexamined Patent Publication (Kokai) No. 127109 is an example, and in this case, the operating rate of the rolling mill is improved as compared with the case where the rolls are individually removed and ground. Incidentally, the above-mentioned JP-A-61-140312 and JP-A-61-15.
4706 discloses a type in which a grindstone is rotated together with rotation of a roll, and JP-A-62-127109 discloses a type in which a grindstone is forcibly rotated by a drive motor. ing. Further, such 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.

On the other hand, such a grindstone for online roll grinding is considered to have a double structure in which the outer peripheral grindstone which also has the same cylindrical shape is integrally fixed to the outer side of the inner peripheral grindstone which has the cylindrical shape. ing. That is, such a grindstone for online roll grinding is out of the machined surface of the grindstone due to vibration of the roll during rolling, or collision with unevenness such as steps or protrusions generated on the outer peripheral surface of the roll due to the uneven wear. Since damage such as chipping (breakage) and cracks easily occurs at the corners of the peripheral edge, for example, a resinoid grindstone with a low elastic modulus that has excellent impact resistance is provided on the outer periphery of a vitrified grindstone that has excellent grinding performance. Of.

However, in such a conventional double-structured grindstone, the difference in the elastic deformation amount when pressed against the roll and the difference in the coefficient of thermal expansion, or the vibration accompanying the rolling and the roll outer peripheral surface There is a risk that the outer peripheral side grindstone may be separated from the inner peripheral side grindstone and may come out to the tip side, that is, the processed surface side due to the impact due to the collision with the unevenness.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the outer peripheral side grindstone from being pulled out.

Means for Solving the Problems In order to achieve such an object, the first means of the present invention comprises:
In the state where the outer peripheral side whetstone of the same cylindrical shape is adhered to the outside of the inner peripheral side whetstone of the cylindrical shape in close contact, and one end face in the axial direction is pressed against the outer peripheral surface of the roll as the processing surface. , A double-structured grindstone that grinds the roll outer peripheral surface online by causing sliding friction between the roll outer peripheral surface, and is fixed to the outer peripheral surface and the outer peripheral surface of the inner peripheral side grindstone. The inner peripheral surface of the outer peripheral grindstone has a concavo-convex shape that meshes alternately in the axial direction.

Further, the second means for achieving the above-mentioned object is that the outer peripheral surface of the inner peripheral side grindstone and the inner peripheral surface of the outer peripheral side grindstone fixed to the outer peripheral surface of the inner peripheral side grindstone are closer to the processing surface in the axial direction. It is characterized in that it has a tapered shape with a diameter increasing toward it.

According to such a double-structured grindstone, due to the uneven shape or the tapered shape provided on the outer peripheral surface of the inner peripheral side grinding wheel and the inner peripheral surface of the outer peripheral side grinding wheel, the inner peripheral side grinding wheel and the outer peripheral surface Since relative movement in the axial direction between the side grindstone is restricted, the outer peripheral side grindstone is suppressed from being separated from the inner peripheral side grindstone, and even if it is separated, the outer peripheral side grindstone is in the axial direction. It is reliably prevented from slipping out to the tip side, and high safety can be obtained.

In addition, the above-mentioned taper shape is different in the adhesion strength between the inner peripheral side grindstone and the outer peripheral side grindstone in order to surely prevent the outer peripheral side grindstone from being pulled out, but the inclination angle with respect to the cylindrical surface parallel to the axis is 0.5 °. Above, the largest possible angle is effective. However, when this inclination angle becomes large, the area of the machined surface of the inner peripheral side grindstone becomes smaller as the grindstone wears, and the grinding performance is impaired. For this reason, it is desirable that the inclination angle is set to be as small as possible within a range where a practically sufficient removal prevention effect can be obtained, for example, within a range of 0.5 ° to 20 °, preferably about 1 ° to 3 °. .

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

FIG. 1 is a longitudinal sectional view of a double-structured grindstone for online roll grinding (hereinafter, referred to as a grindstone at the end) 10 which is an embodiment of the first means of the present invention. This grindstone 10 is for grinding a roll of a hot rolling mill online, and is integrally fixed in a state of being closely adhered to the inner peripheral side grindstone 12 having a cylindrical shape and the outer peripheral side of the inner peripheral side grindstone 12. The outer peripheral side grinding wheel 14 is provided. The inner circumference side grindstone 12 is composed of a vitrified grindstone in which an inorganic substance such as feldspar, porcelain stone, and refractory clay is used as a binder, and its elastic modulus is a grind such as Al ₂ O ₃ , SiC, CBN. 2000 to 7,000 depending on the mixing ratio of the particles and the binder
preferably in the range of kgf / mm ² is set to be 5000 kgf / mm ² approximately, for example GC320K8V, PA220L8V (JIS Standard), etc. CB170M100VN1 (outlet 100) is preferably used. Further, the outer peripheral surface of the inner peripheral side grinding wheel 12 is provided with an annular groove 16 having a plurality of rectangular cross sections, and one end surface in the axial direction, that is, the tip surface 18 is perpendicular to the axial center as it goes toward the outer peripheral side. It is a tapered surface that inclines toward the rear end side at an angle θ from a flat plane.

On the other hand, the outer peripheral side grindstone 14 is composed of a resinoid grindstone in which an epoxy resin is used as a binder, and its elastic modulus is a mixture of abrasive grains such as Al ₂ O ₃ , SiC, CBN and a binder. Depending on the ratio, etc., preferably within the range of 100 to 1000 kgf / mm ^2.
It is set to be about 600 kgf / mm ² , for example GC220J
8BY, WA220J8BY (JIS standard), CBNC220J100BY (outlet
100) and the like are preferably adopted. Further, an annular protrusion 20 having a rectangular cross section is formed on the inner peripheral surface of the outer peripheral side grindstone 14, meshed with the annular groove 16 of the inner peripheral side grindstone 12, and one end face in the axial direction, that is, The front end surface 22 is continuously inclined from the front end surface 18, and its outer peripheral corner portion is chamfered into an R shape having a radius of curvature of about 5 mm. It should be noted that impact-resistant reinforcing materials such as short glass fibers, short carbon fibers, and Al ₂ O ₃ fibers are uniformly mixed into the outer peripheral grindstone 14 if necessary, to increase the strength against impact and to increase the thermal expansion. The deformation is suppressed.

In this way, the outer peripheral surface of the inner peripheral side grinding wheel 12 is provided with the annular groove 16, while the inner peripheral surface of the outer peripheral side grinding wheel 14 is formed with the annular projection 20 that meshes with the annular groove 16 The outer peripheral surface and the inner peripheral surface have an uneven shape that meshes alternately in the axial direction. Also, the above-mentioned tip surface 18,2
Reference numeral 2 corresponds to a processing surface that is pressed by the outer peripheral surface of the roll and performs grinding processing.

Here, to illustrate the dimensions of each part of the grindstone 10 of the present embodiment, the diameter dimensions d ₁ , d ₂ , d ₃ are 240 mm, 220 mm, 120 m, respectively.
The thickness of the outer peripheral side whetstone 14 in the radial direction is 10 mm, and the ratio of the volume of the outer peripheral side grindstone 14 to the total volume of the inner peripheral side grindstone 12 and the outer peripheral side grindstone 14 is about 21%. Also, the angle θ
Is about 0.5 ° to 1 °, the length L in the axial direction is about 48 mm, and the annular groove 16 has a groove width of about 5 mm and a groove depth of 1 mm.
It is about 2 mm. Incidentally, these dimensions, such as the diameter dimension of the roll to be ground and the attitude of the grindstone 10 at the time of grinding,
It is appropriately determined in consideration of various grinding conditions and the like.

Further, the inner peripheral side grindstone 12 and the outer peripheral side grindstone 14 are fixed to one surface of a disk-shaped backing plate 23 having a circular hole in the center. This backing plate 23 is made of Al
₂ O ₃ , SiC, CBN, etc. hardened with abrasive grain phenolic resin, an annular groove 24 is formed in the portion where the outer peripheral grindstone 14 is fixed, and the outer peripheral grindstone 14 has its annular groove. An annular protrusion 26 that meshes with 24 is provided, while a nut 28 is embedded on the other surface of the backing plate. Then, the bolt 30 is fastened to the nut 28 through the mounting flange 33 fixed to the tip of the shaft 32, so that the shaft 32 rotatably instructed by a bearing device (not shown).
A grindstone 10 is attached to and used for roll grinding of a rolling mill.

For example, the usage mode shown in the conceptual diagrams of FIGS. 2 to 4 is one example. In these drawings, reference numeral 40 denotes a work roll which is disposed substantially horizontally on a hot rolling mill (not shown) and is driven to rotate around a rotation axis l, and the grindstone 10 has a rotation axis m of the rotation axis. It is offset downward by a dimension s with respect to the center l, and is disposed in a posture in which it is inclined by an angle α substantially the same as the angle θ with respect to a plane n perpendicular to the rotation axis l. The grindstone 10 is rotatably supported around a rotation axis m via a shaft 32, and the tip surfaces 18, 22 are pressed against the outer peripheral surface of the work roll 40 during hot rolling by a pressing means (not shown). With the rotation of the work roll 40, the work roll 40 is rotated in the counterclockwise direction indicated by the arrow in FIG. 2, and in the axial direction of the work roll 40, that is, in the left-right direction in FIGS. 2 and 4. It is made to reciprocate (oscillate). 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 surfaces 18, 22 of the grindstone 10 are the moving direction of the outer peripheral surface of the work roll 40 and Since the moving speed is different, sliding friction is generated at these contact portions, and the outer peripheral surface of the work roll 40 is ground. In actual roll grinding, a plurality of such grindstones 10 are usually arranged at regular intervals in the axial direction of the work roll 40. Further, FIGS. 2, 3, and 4 are a front view, a right side view, and a plan view, respectively.

Here, when the grinding process is performed by pressing the grindstone 10 on the outer peripheral surface of the work roll 40 during hot rolling, the work roll is
A relatively large impact is applied to the grindstone 10 due to the vibration of 40 and the collision with the irregularities formed on the surface thereof. For this reason,
The above grindstones are only vitrified grindstones that have excellent heat resistance and grinding performance but have high elastic modulus and low impact resistance.
In the case of configuring No. 10, there was a problem that chipping, cracking and the like were likely to occur at the corners of the outer peripheral edge of the tip surface.

On the other hand, the grindstone 10 of the present embodiment includes an inner circumference grindstone 12 made of a vitrified grindstone that provides excellent cutting performance, and an outer circumference grindstone 14 made of a resinoid grindstone having a low elastic modulus and high impact resistance. Since it has a double structure that is integrally provided, impact resistance of the outer peripheral side part is greatly improved, chipping and cracking etc. at the outer peripheral side part are well prevented, and the inner peripheral side The grindstone 12 ensures excellent grinding performance.

In particular, the outer peripheral side grindstone 14 is composed of a resinoid grindstone with an epoxy resin as a binder, and its elastic modulus is 600 kgf / mm ²
In addition to being extremely low, the thickness of the outer peripheral side grinding wheel 14 in the radial direction is 10 mm, so that the occurrence of chipping, cracking, etc. can be effectively prevented. Since the radial thickness of the grindstone 12 on the inner peripheral side is 50 mm, it is possible to obtain sufficient grinding performance for practical use while improving the impact resistance performance on the outer peripheral side portion as described above.

Further, since the outer peripheral side grinding wheel 14 is uniformly mixed with impact resistant reinforcing material such as glass short fiber, carbon short fiber, Al ₂ O ₃ fiber, the outer peripheral side grinding wheel 14 is well deformed by thermal expansion. In addition to being prevented, impact resistance is further improved.

On the other hand, the outer peripheral grindstone 14 of the present embodiment is the inner peripheral grindstone 12
Since it is adapted to be engaged with the annular groove 16 of the backing plate 23 and the annular groove 24 of the backing plate 23, the grindstone 12 on the inner peripheral side of these
Further, the adhesive strength to the backing plate 23 is further improved. Further, since the relative movement in the axial direction with respect to the inner peripheral side grindstone 12 is restricted, the difference in the elastic deformation amount when pressed by the work roll 40, the difference in the coefficient of thermal expansion, or the vibration associated with rolling and the outer peripheral surface of the roll. Despite the impact due to the collision with the unevenness of the
The peeling from 12 is effectively suppressed, and even if it is peeled off, it is reliably prevented from coming out from the inner peripheral side grinding stone 12 to the tip side, and high safety is obtained.
Since the annular groove 16 is also formed at the base end portion of the inner peripheral side grinding wheel 12, that is, the lower end portion in FIG.
The outer peripheral grindstone 14 is reliably prevented from being pulled out up to the usage limit.

Next, another embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the same parts as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted.

FIG. 5 is a vertical cross-sectional view of a double-structured grindstone (hereinafter, simply referred to as grindstone) 50 for online roll grinding, which is an embodiment of the second means of the present invention. The grindstone 10 has a cylindrical shape. The inner grindstone 52 to be formed, the outer grindstone 54 integrally fixed to the outer peripheral side of the inner grindstone 52 in close contact with each other, and the inner grindstone 52 and the outer grindstone 54 on one surface The backing plate 23 is fixed to the backing plate 23. Inner peripheral side grindstone 52, outer peripheral side grindstone 54, respectively, the inner peripheral side grindstone 12 in the first embodiment, is composed of the same grindstone as the outer peripheral side grindstone 14, but the inner peripheral side to be adhered and fixed to each other The outer peripheral surface 56 of the grindstone 52 and the inner peripheral surface 58 of the outer peripheral grindstone 54 are larger in diameter in the axial direction toward the tip surfaces 60, 62 than the cylindrical surface parallel to the rotation axis m. And has a taper shape that is inclined at an angle φ. The tip surfaces 60 and 62 correspond to processed surfaces.

The grindstone 50, like the grindstone 10, has its tip surfaces 60, 62 as shown in FIGS. 2 to 4, for example.
Is used for on-line grinding of the roll while being pressed against the outer peripheral surface of the roll.
The engagement between the inner peripheral side whetstone 52 and the outer peripheral side whetstone 54 restricts relative movement in the axial direction, so that separation between them is suppressed and the outer peripheral side whetstone 54 is It is possible to prevent the peripheral side grindstone 52 from coming out toward the tip side. Also,
In this case, since the outer peripheral surface 56 and the inner peripheral surface 58 only have to be formed into a tape shape, a complicated cutting process for providing the annular groove 16 or a molding die having a complicated shape is not necessary, and the manufacturing cost is reduced. Will be reduced. The inclination angle φ is usually in the range of 0.5 ° to 20 °, preferably about 1 ° to 3 °, in order to prevent the outer peripheral side grindstone 54 from being pulled out while ensuring sufficient grinding performance. The taper angle (JIS: B0154) is set within the range of 1 ° to 40 °, preferably about 2 ° to 6 °.

Further, the double-structured grindstone of FIG. 6 (hereinafter, simply referred to as grindstone)
Reference numeral 70 denotes another embodiment of the second means, and the outer peripheral surface 56 of the inner peripheral side grinding stone 52 and the inner peripheral surface 58 of the outer peripheral side grinding stone 54 in the grindstone 50 are the same as in the first embodiment. In addition, it has a concavo-convex shape that meshes alternately in the axial direction. Also in this case, a sufficient retaining effect can be obtained.

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

For example, in the above-described embodiment, the grindstone 10 is offset with respect to the rotation axis l of the work roll 40, and is pressed against the outer peripheral surface of the work roll 40 in a posture inclined with respect to the plane n,
Although the usage mode in which the grinding is performed so that the work roll 40 can be rotated with the rotation of the work roll 40 has been described, the attitude of the grindstone 10 is changed, and the grindstone 10 is connected to a drive motor, a brake device, or the like and forcedly rotated. The grindstone 10 of the present embodiment can be used in various modes, such as by applying or applying a braking force. In that case, the shape, size, etc. of each part will be changed according to the usage mode. Whetstone 50,7
The same applies to 0.

Further, the inner peripheral side grindstones 12, 52 are both constituted by vitrified grindstones, for example, GC220J8B, WA220J8B (J
IS standard), CBNC170N100B (outlet 100), etc., with relatively high elastic modulus resinoid grindstone, or those in which impact resistant reinforcing materials such as short glass fibers, short carbon fibers, and Al ₂ O ₃ fibers are uniformly mixed Etc. can also be adopted.

Further, although the backing plate 23 is fixedly mounted in each of the embodiments, the backing plate 23 can be omitted by directly embedding the nut 28 in the inner peripheral side grinding stones 12, 52. In the grindstone 50, it is desirable to use the mounting flange 33 of the shaft 32 so as to abut the rear end of the outer peripheral grindstone 54. Alternatively, a disk-shaped backing plate having no hole in the center or a backing plate made of another material may be used.

Further, the outer peripheral side grindstones 14 and 54 of the above examples are mixed with impact resistant reinforcing materials such as glass short fibers, carbon short fibers and Al ₂ O ₃ fibers, but such reinforcing materials are not always necessary. Also, use a resinoid grindstone that uses a binder other than epoxy resin such as phenol resin or polyvinyl alcohol resin, or a grindstone that has a low elastic modulus other than that, such as a rubber grindstone that uses natural rubber or synthetic rubber as a binder. Is also possible.

Further, in the above embodiment, the case where the work roll 40 of the hot rolling mill is grinded online has been described, but the grindstone 10, 50, 70 for online grinding of another roll such as a backup roll that backs up the work roll 40. Of course, the present invention can be similarly applied to a grindstone for grinding rolls of other processing machines including a cold rolling mill.

Further, the outer peripheral wheels 14 and 54 of the grindstones 10 and 70 are integrally formed and fixed to the outer peripheral surface of the inner peripheral wheel 12 and 52, but the outer peripheral wheels 14 and 54 of these are centered on the axis. It is also possible to adopt a structure in which after being divided into a plurality of parts around the periphery and independently formed, they are fixed to the outer peripheral surfaces of the inner peripheral side grinding stones 12, 52 with an adhesive or the like. The grindstone 50 may be manufactured separately without dividing the outer peripheral grindstone 54, and then fitted to the outer peripheral portion of the inner peripheral grindstone 52 and fixed by an adhesive or the like.

Further, the annular grooves 16 and 24 may be formed such that the opening width is smaller than the width dimension of the bottom surface, and instead of providing the annular groove 16 and the annular protrusion 20 in a rectangular shape, the axial center There is no problem even if unevenness having a wavy shape is formed in the direction.

Further, although the outer peripheral surface 56 and the inner peripheral surface 58 are tapered over the entire length in the axial direction, a part of the tip end side may be a cylindrical surface parallel to the rotational axis m or the like.

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 vertical cross-sectional view of a dual structure 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 double-structured grindstone of FIG. 1, FIG. 2 is a front view, and FIG. 3 is a right side view.
FIG. 4 is a plan view. FIG. 5 is a longitudinal sectional view of a dual structure grindstone for online roll grinding according to another embodiment of the present invention. FIG. 6 is a vertical sectional view showing still another embodiment of the present invention. 10,50,70: Double structure whetstone 12,52: Inner circumference whetstone 14,54: Outer circumference whetstone 16: Annular groove 18,22,60,62: Tip surface (working surface) 20: Annular protrusion, 40: Work roll 56: Outer surface, 58: Inner surface m: Wheel axis

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kanji Hayashi 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Plant (72) Inventor Takayuki Goto 1-chome, Koura, Kanazawa-ku, Yokohama, Kanagawa Prefecture No. 8 1 Mitsubishi Heavy Industries, Ltd. Basic Technology Research Laboratory (72) Inventor Hisao Matsushima 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Works

Claims (2)

[Claims] 1. A cylindrical outer peripheral grindstone is also integrally fixed to the outside of a cylindrical inner peripheral grindstone in a state of being in close contact with one another, and one end face in the axial direction is a machining surface on the outer peripheral surface of the roll. A double-structured grindstone that grinds the roll outer peripheral surface online by generating sliding friction with the roll outer peripheral surface in a pressed state, wherein the outer peripheral surface of the inner peripheral side grindstone and the A double-structured grindstone for online roll grinding, wherein an inner peripheral surface of the outer peripheral grindstone fixed to the outer peripheral surface has an uneven shape which is meshed alternately in the axial direction. 2. A cylindrical outer peripheral grindstone is also integrally fixed to the outer side of a cylindrical inner peripheral grindstone in a state of being in close contact with one another, and one end face in the axial direction is a machined surface on the outer peripheral surface of the roll. A double-structured grindstone that grinds the roll outer peripheral surface online by generating sliding friction with the roll outer peripheral surface in a pressed state, wherein the outer peripheral surface of the inner peripheral side grindstone and the A double structure for online roll grinding, characterized in that the inner peripheral surface of the outer peripheral side grinding stone fixed to the outer peripheral surface has a taper shape whose diameter increases toward the processing surface side in the axial direction. Whetstone.