JP4311028B2 - Surface layer cutting device and method for manufacturing steel slab - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface cutting apparatus that performs cutting of a material surface with a blade, and a method for manufacturing a steel slab having a step of cutting the surface with the surface cutting apparatus.
[0002]
[Prior art]
In order to improve the quality of steel sheets, for example, by cutting the surface of a heated slab or rough bar in a hot rolling production facility, surface defects such as oxides on the surface part of the steel slab are removed. Removal in the hot rolling stage has been studied. In order to realize this industrially, the surface of a steel slab in a hot state must be plane-cut as a preceding or intermediate step while performing a normal hot rolling step.
[0003]
As a method of performing plane cutting, it can be roughly classified into milling (rolling) using a rotary blade, peeling processing (skin cutting) using a fixed blade, and the like.
[0004]
In general milling with a rotary blade, cutting blades are arranged on the outer periphery of the rotary blade, cutting is performed by the rotation of the rotary blade, and the material to be cut is cut by the feed amount per rotation of the rotary blade. Although the reaction force is small, the feed rate cannot be increased and the amount of cutting per unit time is small. That is, there is a problem that processing efficiency is low.
[0005]
On the other hand, in the peeling process using a fixed blade, since the cutting is continuously performed at a specific portion of the cutting blade, the life of the cutting blade becomes a problem, and there are problems that the cutting amount cannot be increased and the cutting speed cannot be increased.
[0006]
In order to extend the life of the cutting blade, there is a method of switching the used portion of the cutting blade and using a cutting device in which the cutting blade is a circular blade. In many cases, the cutting blade does not rotate during cutting, and when the work is interrupted, the circular blade is released, the attachment angle is rotated and fixed again, and the used portion of the circular blade is switched for cutting. .
[0007]
Further, in Japanese Patent Application Laid-Open No. 58-143908, as shown in FIG. 9, the rotation shaft 910c of a rotatable disc-shaped cutting blade 910 is arranged so as to have a skew angle θ with respect to the cutting direction X. A method of rotating a circular blade by a cutting reaction force during cutting is disclosed. As a result, the cutting blade usage position is constantly updated during cutting, so that the switching operation of the cutting blade usage position becomes unnecessary.
[0008]
[Problems to be solved by the invention]
However, the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 58-143908 is used for the purpose of removing projections such as weld beads or projections existing in narrow portions. If this technique is to be used for plane cutting, a circular blade is used and the cutting edge is a circular arc, so it is difficult to cut the plane smoothly.
[0009]
That is, in a circular blade, the cutting edge becomes a circular arc having a certain radius of curvature. When cutting in the direction of the central axis of the circular blade, the radius of curvature of the cutting edge is the radius D / 2 of the circular blade itself. In the case of the technique described in Japanese Patent Application Laid-Open No. 58-143908, the rotary shaft 910c of the circular blade is inclined by the skew angle θ with respect to the cutting direction X as shown in FIG. The cutting edge 910e is an elliptical arc. At this time, the radius of curvature of the portion where the workpiece 21 is cut is smaller than the radius D / 2 of the circular blade. The fact that the radius of curvature is small means that the cutting width W becomes small with respect to the cutting amount t at the deepest cutting position. In order to smoothly cut a predetermined surface width, the number of cutting blades is set to be small. It becomes necessary to increase the number of reciprocating scans.
[0010]
The skew angle θ is for generating a rotational force that exceeds the frictional resistance μF due to the pressing force F of the cutting blade. If the cutting force in the bead flow direction is P,
Psinθ> μF
The skew angle θ that satisfies this condition is required. Since the technique described in Japanese Patent Application Laid-Open No. 58-143908 is intended for cutting projections such as weld beads as described above, a desirable skew angle is 20 to 30 °. In this case, when a flat surface layer is to be cut, since there is no frictional force due to the protrusions, a skew angle larger than the above value is often required for stable rotation.
[0011]
That is, in the method described in Japanese Patent Application Laid-Open No. 58-143908, when performing planar cutting with a surface layer of several millimeters, the cutting width W per cutting blade must be reduced. That is, when the cutting width W is increased, the cutting amount t is increased, and the object of performing planar cutting (peeling) with a surface layer of several millimeters cannot be achieved.
[0012]
In addition, when cutting a projection such as a weld bead, it is easy to rotate the cutting blade according to the cutting reaction force. It is not easy to rotate the cutting blade according to the cutting reaction force.
[0013]
As described above, it is difficult to realize flat cutting without hindering the normal hot rolling process with the conventional cutting technique. When performing planar cutting with a cutting edge having a certain curvature, such as a circular blade, the closer the angle formed by the surface of the workpiece and the cutting edge in the cross section viewed from the cutting direction of the cutting locus, the closer the surface is to the cutting member. Since the gap becomes larger, there is a problem that chips are likely to flow out above the surface, resulting in poor removal and burrs. In particular, burrs are easily generated in the direction in which the circular blade rotates.
This is shown in FIG. FIG. 10 is a diagram illustrating a state in which the workpiece 2 is being cut by the rotary blade 10 that rotates around the rotary shaft 10a. Reference numeral 13 denotes a cutting edge, 21 denotes a surface of the workpiece, 23 denotes a cutting edge start locus, and 25 denotes a cutting edge end locus. As shown in the figure, burrs 41 are likely to occur in the vicinity of the cutting edge end locus 25.
In addition, when the number of cutting blades is increased or the number of reciprocating scans is increased in order to perform planar cutting with a predetermined cutting width that is equal to or greater than the width of the cutting blade, a portion where a plurality of cutting tracks overlap for the same reason as described above. However, removal defects and burrs are most likely to occur.
[0014]
The present invention has been made in view of such circumstances, and can cut the surface layer of the workpiece at high speed and stably, and produce a steel slab (further rolling to produce a steel product as a final product). It is an object of the present invention to provide a surface layer cutting device suitable for performing surface cutting of a steel block used for the purpose of manufacturing, and a method of manufacturing a steel slab using the surface cutting device.
[0015]
[Means for Solving the Problems]
The first means for solving the above-mentioned problems has a circular cutting blade held rotatably, and a side surface continuous to the circumferential portion of the cutting blade is a rake face for cutting, and the cutting blade A surface layer cutting apparatus comprising one or more cutting members whose rotating shaft is inclined in both the cutting direction and the cutting width direction from a normal line on the surface of the workpiece Is .
[0016]
In this means, unlike the method described in Japanese Patent Laid-Open No. 58-143908, the side surface continuous with the circumferential portion of the cutting edge is used as a rake face for cutting. Compared with the method described in, the rotary axis of the circular cutting edge rotates during cutting with respect to the circular cutting edge without having to be greatly inclined in the cutting width direction from the normal line on the surface of the workpiece. Can give power.
[0017]
Therefore, the cutting width with respect to the cutting depth can be increased, and the cutting blade can be rotated by the cutting reaction force while taking a sufficient cutting width per cutting blade even when performing planar cutting with a surface layer of several millimeters. . As a result, the portion of the cutting blade used for cutting can be naturally changed with the cutting, and the switching operation of the cutting blade use position becomes unnecessary. Therefore, cutting work can be performed with high work efficiency.
[0018]
In addition, so-called plane cutting often refers to processing into a flat surface, but in this specification, plane cutting and surface layer cutting are the bare metal of the material to be cut from the surface (when the material to be cut is a metal) ) It refers to the case of cutting itself, and the cutting depth is appropriate.
[0019]
In other words, the surface cutting device targeted by the present application is not for cutting only projections such as burrs (although such cutting is possible, of course), flat parts such as steel slabs and members with large curvatures. It is for cutting the surface (including the case where the plane is wobbling).
[0020]
The second means for solving the above-mentioned problem is the first means, characterized in that the inclination of the rotating shaft from the normal to the cutting width direction is 10 ° or less. Is .
[0021]
In the practical first means, as will be described later in the embodiment, when the inclination of the rotating shaft from the normal to the cutting width direction exceeds 10 °, the chips are caught in the rotating cutting blade. Since it becomes easy, it is preferable to make this value 10 degrees or less.
[0022]
The third means for solving the above-mentioned problems has a circular cutting blade held rotatably, and a side surface continuous with a circumferential portion of the cutting blade is a rake face for cutting, and the cutting blade One or more cutting members that are in contact with the material to be cut so that the rotation axis is inclined in the cutting direction from the normal line on the surface of the material to be cut, and the rotation axis is located at substantially the center of the cutting width; A surface layer cutting apparatus comprising: a rotating unit that rotates the cutting blade at a predetermined timing to renew the cutting blade surface. Is .
[0023]
As described above, when the rotary axis of the cutting edge is simply inclined in the cutting direction from the normal line on the surface of the workpiece, a cutting reaction is required when a circular cutting edge is used to cut a surface layer of several millimeters with a predetermined width. It is not easy to rotate the cutting blade by force. In this means, there is provided a rotating means for rotating the cutting blade at a predetermined timing to renew the cutting blade surface, so that the cutting blade is rotated by this rotating means, and as a result, the portion of the cutting blade used for cutting. Can be changed with cutting. Therefore, it is not necessary to switch the cutting blade use position. Therefore, cutting work can be performed with high work efficiency.
[0024]
The fourth means for solving the problem is any one of the first means to the third means, and an inclination angle of the rotation axis from the normal to the cutting direction is 30 ° or less. Characterized by being Is .
[0025]
As described above, when the angle of inclination of the rotating shaft from the normal to the cutting direction is increased, the radius of curvature of the part where the workpiece is cut becomes smaller than the radius of the circular blade. The cutting width becomes smaller than the cutting amount at the deep cutting position. In this means, the rotation axis is inclined in the cutting width direction from the normal line, or a rotation means for renewing the cutting blade surface by rotating the cutting edge is provided. Therefore, the normal line of the rotation axis is provided. The cutting blade can be rotated without increasing the angle of inclination in the cutting direction. Therefore, the inclination angle of the rotating shaft from the normal to the cutting direction is limited to 30 ° or less where the cutting width is not so small.
[0026]
A fifth means for solving the above problem is any one of the first to fourth means, and has two or more cutting members and is adjacent on a projection plane viewed from the cutting direction. Each cutting member is arranged in the cutting width direction so that the circular cutting edge trajectories partially overlap each other Is .
[0027]
In this means, since the number of cutting members is increased so that the adjacent circular cutting edge trajectories partially overlap each other, the width that can be cut by one scan can be widened. Since the degree of overlap of the cutting edge locus (arc shape) of the circular blade determines the surface roughness after cutting, it may be determined according to the target surface roughness.
According to a sixth means for solving the above-mentioned problem, the angle on the side on which the rotation axis is inclined is 25 out of the angle formed by the circular cutting edge and the surface of the workpiece in the cross section when the cutting locus is seen from the cutting direction. A surface layer cutting device characterized in that the rotation axis of the cutting blade is inclined so as to be less than or equal to °°. Is .
Seventh means for solving the above-mentioned problem is that a plurality of cutting members having a circular cutting edge are arranged in a plurality, or one or more cutting members are moved in the cutting width direction to cut a plurality of times. Of the cutting blade trajectories that overlap each other, the rotation axis of the cutting member that forms the outermost cutting trajectory in the cutting width direction is arranged to be inclined toward the center of the cutting trajectory group. Surface layer cutting machine Is .
The eighth means for solving the above-mentioned problems includes a circular cutting edge that forms the outermost cutting locus in the cutting width direction in the cutting locus group, and a circular cutting edge that forms a cutting locus adjacent thereto. However, the surface cutting device is characterized in that the rotation axis of the cutting blade is inclined so that the angle formed at the intersecting point in the workpiece on the projection surface viewed from the cutting direction is 25 ° or less. Is .
A ninth means for solving the above-described problem is a small-sized cutting locus by a circular cutting blade, which cuts the cutting locus on the side where the rotation axis is inclined and the vicinity of the ridge line on the surface after passing through the circular cutting member. Surface cutting device characterized by mounting a cutting member of Is . The small cutting member is mainly intended to remove burrs generated by the immediately preceding circular blade, and may be a circular blade or a flat blade.
[0028]
The tenth means for solving the above-mentioned problem has a step of cutting the surface with the surface layer cutting device of any one of the first to ninth means, Is .
[0029]
When removing surface defects of steel slabs, so-called slabs, blooms, and steel slabs such as intermediate rolled materials such as rough bars, the life of the cutting equipment must be extended, but the surface roughness due to cutting is Since it is not strict and rough cutting is possible, the cutting tool with this circular blade is effective. This means can cut the surface of the steel slab with high efficiency, especially when performing online surface cutting between the heating furnace and the rolling mill before the heating furnace, the surface cutting can be performed without lowering the line efficiency, Steel slabs to be used for finish rolling can be manufactured with high efficiency, and the manufacturing efficiency of the steel material itself can be increased.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows an outline of a cutting portion of a surface layer cutting apparatus according to a first embodiment of the present invention, and shows an example in which a rotating shaft of a circular blade is inclined only in a cutting direction. (a) is a view seen from the front side in the cutting direction, and (b) is a cross-sectional view cut along a plane parallel to the cutting direction and a projection view of the circular blade 10. FIG.
[0031]
The circular blade 10 having the circular cutting blade 10e is attached so that the rotation shaft 10c thereof coincides with the center of the fixed shaft 11. Here, the rotary shaft 10 c and the fixed shaft 11 of the circular blade 10 are set on the normal direction 21 n side of the cutting surface 21. If the circular blade rotates as it is, the bottom surface of the circular blade contacts the workpiece and the cutting reaction force increases, so the so-called “relief angle” between the bottom of the cutting blade and the surface of the workpiece. β is provided. In the case of a rotating circular blade, that is, it is equivalent to tilting the rotary shaft 10c in the cutting direction X by the forward tilt angle β.
[0032]
Here, since the so-called “squeeze angle” α in the cutting is changed by the inclination of the rotation axis 10c of the circular blade 10 by the forward inclination angle β, the rotation axis 10c of the circular blade has a forward inclination angle β as shown in FIG. In this state, the cutting edge shape is determined so that the squeeze angle with respect to the surface 21 of the workpiece is a predetermined angle α ′. That is, any squeeze angle can be set separately from the forward inclination angle β of the rotation axis of the circular blade.
[0033]
The forward tilt angle β is important in reducing friction with the work material. Especially when cutting soft materials or high-temperature steel materials, the number of surfaces that come into contact with the bottom surface of the circular blade increases. Must be set larger.
[0034]
However, when the clearance angle β, that is, the forward inclination angle β is increased, as shown in FIG. 1, an ellipse, which is a projection of the circular cutting edge 10e viewed from the cutting direction, increases the short radius b while keeping the long radius a constant. Therefore, the radius of curvature of the circular cutting edge 10e at the portion that comes into contact with the workpiece is reduced.
[0035]
When the radius of curvature is small, the cutting width W0 with respect to the predetermined depth of cut t becomes small. Therefore, in order to secure the cutting width, it is necessary to make the forward inclination angle β as small as possible.
[0036]
Further, when the rotary shaft 10c of the circular blade is inclined only in the cutting direction X as shown in FIG. 1, since it does not rotate during cutting, the circular blade is rotated by a certain angle after cutting by external force as shown in FIG. It is designed to rotate inside. In this way, the life of the circular cutting edge 10e is extended by sequentially changing the portion of the circular cutting edge 10e used for cutting.
[0037]
In this embodiment, since the side surface 10a continuous to the circumferential portion of the cutting edge is used as a rake face for cutting, the cutting width W0 with respect to a predetermined cutting amount t can be increased.
[0038]
(Second Embodiment)
FIG. 4 shows an outline of the cutting part of the surface layer cutting apparatus according to the second embodiment of the present invention, and shows an example in which the rotary shaft of the circular blade is inclined in the cutting direction and the cutting width direction. . (A) is the figure seen from the cutting direction front side, (b) is AA sectional drawing and the projection figure of the circular blade 10. FIG.
[0039]
This not only tilts the rotation axis 10c of the cutting tool forward by a forward tilt angle β in the cutting direction X with respect to the normal direction 21n on the cutting surface 21, but also tilts it in the cutting width direction Y, which is a direction perpendicular to the cutting direction X. Inclined by an angle γ (commonly called camber angle γ).
[0040]
By doing so, it is aimed to rotate the circular blade by the cutting reaction force, but when cutting the surface of the plane using the circular blade, with respect to the normal direction 21n on the surface of the workpiece, Since it is possible to increase the cutting width W1 when the rotary shaft 10c of the circular blade is not inclined so much, it is not a good idea to incline excessively, that is, to increase β.
[0041]
When the rotary shaft 10c of the circular blade is set in the vicinity of the normal direction 21n of the cutting surface 21 as in the present case, the condition as to whether or not the circular blade 10 is rotated only by the cutting reaction force is the inclination of the rotary shaft 10c. It changes slightly depending on the angle. When the rotation axis is tilted in the cutting width direction Y (when γ is provided), it is obvious that the rotation is facilitated by the cutting reaction force, but the cutting width W1 with respect to the cut t of a certain surface layer becomes small, so it becomes unnecessary. It cannot be tilted.
[0042]
In this embodiment, since the side surface 10a continuous to the circumferential portion of the cutting edge is used as a rake face for cutting, the cutting width W0 with respect to a predetermined cutting amount t can be increased. At the same time, the circular blade can be rotated by the cutting reaction force even if the rotary shaft 10c of the circular blade is not inclined much in the cutting width direction Y, which is a direction perpendicular to the cutting direction X.
[0043]
(Third embodiment)
FIG. 5 shows an outline of a cutting portion of a surface layer cutting apparatus according to the third embodiment of the present invention.
[0044]
In the first embodiment and the second embodiment, the configuration per circular blade has been shown, but when the predetermined cutting width is equal to or larger than the cutting width of one circular blade, after cutting once in the cutting direction Therefore, it is necessary to perform so-called scanning in which a predetermined amount of sliding (shift) in the cutting width direction is repeated and cutting is repeated. This requires cutting time for the number of scans, and the machining efficiency is reduced. In addition, there is a method of cutting with one large circular blade corresponding to a predetermined cutting width. However, since the circular blade has an influence, the cutting amount is negative and the surface is not smooth and smooth.
[0045]
In order to shorten the cutting time, improve the working efficiency, and smooth the surface, a plurality of circular blades 10, 210, 310 are provided in the cutting width direction Y and the cutting direction X, as shown in FIG. In this way, a plurality of circular cutting edge trajectories 10e, 210e, 310e as viewed from the cutting direction X may be arranged so as to partially overlap each other inside the cutting surface 21. Naturally, it is necessary to set the number of circular blades so that the cutting reaction force is within the tolerance of the apparatus. Reference numerals 11, 211, and 311 denote fixed shafts of the circular blades 10, 210, and 310, respectively.
[0046]
FIG. 6 is a view showing details of the cutting edge portion of the circular blade in the above. The overlapping degree LAP of the cutting edge locus (arc shape) 10e, 210e, 310e of the circular blade determines the surface roughness after cutting. That is, when the maximum depth of cut tmax is constant, if the LAP is increased, the minimum depth of cut tmin increases. Therefore, the difference between the maximum depth of cut tmax and the minimum depth of cut tmin is reduced, and the surface roughness is improved. .
[0047]
Since the number of circular blades for processing a predetermined cutting width at the same time and this surface roughness are contradictory, they are set to an appropriate amount depending on the cutting conditions.
[0048]
The structure in which the circular blade rotates is not limited to these embodiments. For example, a bearing structure in which an integrally structured shaft protruding from the circular blade is attached to a tool post that rotatably holds the shaft. Is also possible.
(Fourth embodiment)
In the first to fourth means, the angle range in which effective surface layer cutting is possible was shown. However, depending on the material of the material to be cut and the cutting conditions, in FIG. In some cases, a burr 41 may be generated at a location 25 that finally contacts the workpiece 20 in the rotation direction. Therefore, in order to make the surface 21 of the workpiece 20 smooth without causing burrs 41 or the like, the setting of the angle at which the rotary shaft 11 of the circular blade is inclined becomes more important.
As shown in FIG. 11, of the angles ψ and φ formed between the cutting edge 13 of the circular blade 10 and the surface 21 of the workpiece as viewed from the cutting direction, the angle of the last portion 25 that contacts the workpiece in the rotational direction of the circular blade. That is, φ, that is, the angle φ on the side where the rotating shaft 11 is inclined is important. If the angle φ is 25 ° or less, the outflow of chips can be suppressed. However, if the angle φ exceeds 25 °, the generation rate of burrs increases due to outflow of chips, which is not preferable. If possible, it is desirable to make the angle 15 ° or less.
In this embodiment, even when cutting with one circular blade, a smooth surface can be obtained.
(Fifth embodiment)
When the angle setting as described above is not easy, or when other settings are affected by limiting the angle setting, the circular blade other than one is not limited to the angle setting as described above. Embodiments are possible.
As described above, the portion where the burr 41 as shown in FIG. 10 is likely to occur is the contact between the cutting edge 13 of the circular blade 10 and the surface 21 of the workpiece 21 on the side where the rotary shaft 11 of the circular blade 10 is inclined. Location 25. Then, when the burr | flash 41 generate | occur | produces, there exists a method of removing the generated burr | flash 41 with the following circular blade which cuts the adjacent surface. In this case, it is not necessary to set the angle φ as in the fourth embodiment.
As a method of cutting adjacent surfaces, for example, after cutting once with one circular blade, the circular blade is moved in the cutting width direction by an amount slightly smaller than the cutting width, and a position where it overlaps with the already cut cutting locus. Then there is a method of cutting again like the last time. Alternatively, there is a method in which a plurality of two or more circular blades are arranged so that adjacent circular blades form a cutting locus that overlaps with a cutting locus of a circular blade that is cut in advance. Since both methods have the same concept regarding the arrangement viewed from the cutting direction, the latter will be described as an example here.
FIG. 12 is an example in which circular blades A10 to Z10 are arranged in the cutting width direction Y so that the cutting trajectories A22 to Z22 overlap. The circular blade A10 and the circular blade Z10 are on the outermost side in the cutting width direction, and the rotation axes A10c and Z10c are both inclined inward in the cutting width direction.
When the circular blade A10 cuts in the cutting direction X, the circular blade A10 forms a cutting locus A22 starting with the cutting start locus A23 and reaching the cutting end locus A25 with respect to the workpiece 21. The cutting end locus A25 may generate a burr A41. However, since the circular blade B10 forms a cutting locus B22 that starts at the cutting continuation locus B24 and reaches the cutting end locus B25, the burr A41 is generated. However, it can be removed by the circular blade B10 together with the cutting end locus A25.
A burr B41 may also be generated in the cutting end locus B25 by the circular blade B10. However, if a circular blade having the same inclination as the circular blade B10 is arranged in the cutting width direction Y, the preceding circular blade It is obvious that the following circular blade can be removed from the burr. Therefore, only the circular blade Z10 that is arranged on the outermost side in the cutting width direction Y and cuts last will be described.
In the circular blade Z10, since the rotation axis Z10c is inclined inward in the cutting width direction, the cutting start locus Z23 is the outermost cutting locus in the cutting width direction. Since the circular blade Z10 forms Z22 starting from the cutting start locus Z23 and reaching the cutting completion locus Z26, it is the cutting completion locus Z26 that finally contacts the workpiece. That is, the generation of the burr 41 is an angle formed by the workpiece 20 and the circular blade 10 in the cutting completion locus 26.
In FIG. 12, AW0, BW0, and ZW0 are the widths actually cut by the circular blades A10, B10, and Z10, respectively, and AW, BW, and ZW are finally left by the circular blades A10, B10, and Z10, respectively. The width of the cutting locus.
As shown in FIG. 13, when the rotation axis Z10c (omitted in the drawing) of the circular blade Z10 that is the outermost in the cutting width direction Y is inclined outward, the workpiece 20 and the circular blade on the cutting completion locus Z26 The formed angle φ is the same angle as the angle φ formed between the workpiece 20 and the circular blade 10 in the cutting end locus Z25 of the other circular blades. φ needs to be 25 ° or less, and the limit of angle setting becomes narrow.
Therefore, as shown in FIG. 14, when the rotation axis Z10c (omitted in the drawing) of the circular blade Z10 which is the outermost in the cutting width direction Y is inclined inward, the workpiece 20 and the circular blade on the cutting completion locus Z26 Is smaller than the angle φ formed between the workpiece 20 and the circular blade 10 in the cutting end locus Z25 of the other circular blade, and therefore even if the inclination angle of the rotary shaft 10c of the circular blade 10 is increased. Burrs are less likely to occur.
If the rotation axis Z10c of the outermost circular blade Z10 in the cutting width direction is inclined so that the angle η between the workpiece 20 and the circular blade Z10 in the cutting completion locus Z26 is 25 ° or less, the cutting completion locus Since the generation of burrs in Z26 can be suppressed, the setting range of the inclination angle of the rotating shaft 10c can be expanded.
If the angle η formed exceeds 25 °, it is not preferable because the generation rate of burrs increases due to the outflow of chips. If possible, it is desirable to make the angle 15 ° or less.
FIG. 15 shows the arrangement of the circular blades 10 as viewed from the cutting direction X, as in the above (FIG. 12). The circular blade A10 and the circular blade Z10 are on the outermost side in the cutting width direction, and their rotation axes A10c and Z10c are both Although it is inclined inward in the cutting width direction, the cutting order is different from the above, and the last cutting is not the circular blade Z10 which is the outermost in the cutting width direction Y.
Since the circular blade Z10 forms the cutting end trajectory Z25, there is a high possibility that burrs will occur on the ridgeline, but since it is removed by the cutting trajectory B22 of the circular blade B10, what is finally important is the completion of cutting It is an angle formed by the workpiece 20 and the circular blade B10 in the locus B26.
Since this is clearly the same as the above example (FIG. 12) when viewed from the cutting direction X, it is possible to suppress the occurrence of burrs in the same way.
(Sixth embodiment)
In order to cut the surface layer smoothly with the circular blade 10, it is possible to remove burrs generated in the preceding cutting locus with the circular blade 10 that forms the subsequent cutting locus by overlapping a plurality of cutting locus. is there. Therefore, the angle setting of the rotation axis 10c of the circular blade 10 should just consider the angle setting of the rotation axis Z10c of the circular blade Z10 which forms the outermost cutting locus Z22 in the cutting width direction Y. Not only the rotation axis angle but also the circular blade Z10 may change the diameter of the circle, and may not be a circular blade.
FIG. 16 shows an example in which the cutting member that forms the outermost cutting locus in the cutting width direction Y is not a circular blade but a flat blade S10. The flat blade S10 may be a small cutting member as long as the main purpose is to remove burrs on the adjacent cutting end locus B25. If it is a normal cutting member which is not such a circular blade, since the shape of a cutting blade is arbitrary, it is easy to make it into the shape where a burr | flash does not generate | occur | produce easily.
Although the means for suppressing the occurrence of burrs on the surface of the workpiece has been described above, the cutting completion locus Z26 of the circular blade Z10 that is the outermost in the cutting width direction Y, such as the end of the workpiece, as shown in FIG. When the surface does not intersect with the surface 21 of the material to be cut, it is not necessary to consider the above means.
[0049]
【Example】
A hot steel material around 900 ° C. was cut with a cutting device using a circular blade according to the present invention. At that time, the inclination of the rotary shaft of the circular blade was changed appropriately. The used circular blade had a diameter D = 250 mm and was cut by t = 2 mm in the surface layer of the steel material.
[0050]
When the angle of the rotation axis of the circular blade is set to the forward tilt angle β = 6 ° and the camber angle γ = 4 °, the circular blade rotates reliably and the chips are discharged in the cutting width direction without being caught by the cutting blade. It was done. The relationship between the rotation of the circular blade and the shape of the chips with respect to the setting of the forward tilt angle β and the camber angle γ varies depending on numerical values such as the diameter D of the circular blade, the steel material temperature, and the cutting depth t.
[0051]
FIG. 7 shows what happens to the cutting width W depending on the setting of the forward tilt angle β and the camber angle γ when the circular blade has a diameter D = 250 mm and the steel layer is cut by cutting t = 2 mm. The meaning of the graph is a contour map in which the cutting width is regarded as height.
[0052]
The non-cuttable region in this figure is a portion 10f (cylindrical surface of the circular blade) that is not the circular cutting edge 10e of the circular blade when the forward tilt angle β is small or the camber angle γ is large as shown in FIG. ) Represents the angle setting region of the rotation axis that bites into the workpiece and makes normal cutting impossible.
[0053]
Further, in order to increase the cutting width per circular blade, it is better that both the forward tilt angle β and the camber angle γ are smaller. However, as the forward tilt angle β is reduced, the region approaches the non-cuttable region. In order to prevent cutting from being impossible due to a subtle angle error, it is necessary to consider a safety margin and make an angle with a margin. On the other hand, when the camber angle γ is reduced, the rotational effect on the circular blade is reduced and the rotation becomes impossible. Therefore, it is necessary to incline the camber angle γ to an appropriate size, but this is also affected by the balance between the rotary shaft diameter of the circular blade 10 and the fixed shaft 11 and the frictional force.
[0054]
Therefore, considering the case of machining the required cutting width, the camber angle γ can be maximized by the contour line in FIG. 7, and the forward tilt angle having an angular margin can be set from the uncuttable region. . For example, when the diameter D of the circular blade is D = 250 mm and the steel layer is cut by t = 2 mm as described above, when the cutting width W = 100 mm is to be cut, the camber angle γ = 4 ° is the largest from the contour line of FIG. With respect to the value, the forward tilt angle β at that time is 6 °, and there is a margin from the angle of about 3.5 ° in the non-cuttable region, so it can be seen that the angle is appropriate.
[0055]
Thus, it was found that there are appropriate values for the forward tilt angle β and the camber angle γ. However, the relationship shown in FIG. 7 needs to be obtained under each predetermined condition because the aspect varies greatly if the diameter or depth of cut of the circular blade changes.
[0056]
However, if both the forward tilt angle β and the camber angle γ are increased, the cutting width per circular blade is reduced, so that the forward tilt angle β is practically 30 ° or less and the camber angle γ is 10 °. It becomes effective in the following, and further, it is effective when the forward tilt angle β is 1 ° to 10 ° and the camber angle γ is 1 ° to 8 °. Preferably, the forward tilt angle β is 2 ° to 8 ° and the camber angle γ is 2 When the angle is set to 0 to 6 °, the ratio of the cutting width W to the constant cutting amount t (aspect ratio = aspect ratio) can be increased, and chips that can be easily rotated and processed by the cutting reaction force can be easily obtained. That is, the ratio of the cutting width W to the diameter D of the circular blade can be increased, and the circular blade can be used effectively.
[0057]
Further, as a result of experiments by the inventors, it has been clarified that, when the camber angle γ is larger than the above value, chips become difficult to dispose of chips because the chips involve a circular blade.
When cutting a hot steel material near 900 ° C. with a cutting blade using a circular blade having a diameter D = 250 mm according to the present invention by cutting the surface layer of the steel material by t = 2 mm, the inclination angle of the rotary axis of the circular blade is When the inclination angle β = 6 ° and the camber angle γ = 4 °, the angle ψ = 3.5 ° between the circular blade 10 and the workpiece 20 on the cutting start locus 23 and the circle on the cutting end locus 25 The angle φ between the blade 10 and the workpiece 20 was 7.6 °, and no burrs were generated on the cutting end locus 25 and the cutting start locus 23.
[0058]
【The invention's effect】
As described above, according to the present invention, the surface layer of the workpiece can be cut at high speed and stably, and the surface layer cutting device suitable for performing surface cutting of a steel slab, and the surface thereof A method of manufacturing a steel slab using a cutting device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a cutting part of a surface layer cutting apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating that an arbitrary squeeze angle can be set separately from the forward tilt angle of the rotation axis of a circular blade by changing the shape of the blade edge.
FIG. 3 is a diagram showing an example in which a circular blade is rotationally driven by an external force in a case where planar cutting is performed by inclining the rotation axis of the circular blade only in the cutting direction.
FIG. 4 is a diagram showing an outline of a cutting portion of a surface layer cutting device according to a second embodiment of the present invention.
FIG. 5 is a diagram showing an outline of a cutting portion of a surface layer cutting device according to a third embodiment of the present invention.
6 is a view showing details of a cutting edge portion of a circular blade in FIG. 5. FIG.
FIG. 7 is a diagram showing the relationship between the rotational axis angle of a circular blade and the cutting width in an example of the present invention.
FIG. 8 is a diagram showing the reason why cutting becomes impossible by setting the rotation axis angle.
FIG. 9 is a view showing a conventional method of cutting a weld bead using a circular blade.
FIG. 10 is a diagram illustrating a case where burrs are generated by a circular blade.
FIG. 11 is a diagram showing a cutting part of a surface layer cutting device according to a fourth embodiment of the present invention.
FIG. 12 is a view showing a cutting part of a surface layer cutting device according to a fifth embodiment of the present invention.
FIG. 13 is a diagram illustrating a normal angle formed by a circular blade and a workpiece.
FIG. 14 is a view showing a method for reducing an angle formed by a circular blade and a workpiece.
FIG. 15 is a view showing a cutting part of another example of the surface layer cutting apparatus according to the fifth embodiment of the present invention.
FIG. 16 is a view showing a cutting portion of a surface layer cutting device according to a sixth embodiment of the present invention.
FIG. 17 is a diagram illustrating an example of cutting an end portion of a workpiece that does not depend on the conditions of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Circular blade, 10a ... Squee face of circular blade, 10b ... Flank of circular blade, 10c ... Rotary shaft of circular blade, 10e ... Cutting edge of circular blade, 10f ... Side surface (cylindrical surface) of circular blade, 11 DESCRIPTION OF SYMBOLS ... Fixed axis, 20 ... Material to be cut, 21 ... Surface of material to be cut, 21n ... Normal to the surface of material to be cut, 22 ... Cutting locus, 23 ... Cutting start locus, 24 ... Cutting continuation locus, 25 ... End of cutting Trajectory, X ... cutting direction, Y ... cutting width direction, α ... squeeze angle, α '... any squeeze angle, β ... forward tilt angle (relief angle) of the rotary axis of the circular blade in the X direction, γ ... of the circular blade The tilt angle (camber angle) of the rotating shaft in the Y direction, D: Diameter of the circular blade, a: Long radius of the ellipse when the circular blade is viewed from the cutting direction, b: When the circular blade is viewed from the cutting direction Ellipse short radius, W ... cutting width, t ... cutting amount, A10, B10, Z10 ... circular blade, A10c, B10 , Z10c ... axis of rotation, A22, B22, Z22 ... cutting trajectory, A23, Z23 ... the start of cutting locus, B24, Z24 ... cutting continued trajectory, A25, B25, Z25 ... cutting end locus, B26, Z26 ... cutting completion locus

Claims (8)

In the surface layer cutting device for plane cutting the surface of the workpiece,
It has a circular cutting edge held rotatably, a side continuous to the circumferential portion of the cutting edge is a rake face for cutting, and the rotation axis of the cutting edge is from a normal line on the surface of the workpiece 1 or more cutting members which are inclined in both the cutting direction and the cutting width direction, and the inclination of the rotating shaft from the normal to the cutting width direction is 10 ° or less. apparatus. The surface layer cutting device according to claim 1 , wherein an inclination angle of the rotation axis from the normal to the cutting direction is 30 ° or less. The two or more cutting members are provided, and the cutting members are arranged in the cutting width direction such that adjacent circular cutting edge trajectories partially overlap each other on a projection plane viewed from the cutting direction. The surface layer cutting device according to claim 1 or 2 . The rotation axis of the cutting edge is such that the angle on the side on which the rotation axis is inclined is 25 ° or less among the angles formed by the circular cutting edge and the surface of the workpiece in the cross section when the cutting locus is viewed from the cutting direction. The surface layer cutting device according to any one of claims 1 to 3 , wherein the surface cutting device is inclined. Two or more cutting members having a circular cutting edge are arranged , or one or more cutting members are moved in the cutting width direction and cut a plurality of times to cut a part of the cutting blade locus that overlaps each other. the rotation shaft of the cutting member forming the cutting trajectory the outermost in the width direction, the preceding claims, characterized in that the arrangement which is inclined toward the center of the cutting width direction of the cutting trajectory group claim 4 The surface layer cutting apparatus of any one of them. A circular cutting edge that forms the outermost cutting locus in the cutting width direction in the cutting locus group , and a circular cutting edge that forms a cutting locus adjacent to the circular cutting edge are cut on the projection surface as viewed from the cutting direction. The rotating shaft of the cutting blade is inclined so that the angle formed at the point of crossing within 25 degrees or less is defined in any one of claims 1 to 3 and claim 5. The surface layer cutting device described. The cutting locus by the circular cutting blade is attached with a small cutting member that cuts the cutting locus on the side where the rotation axis is inclined and the vicinity of the ridgeline of the surface after passing through the circular cutting member. The surface layer cutting device according to claim 1 or 2 . A method for producing a steel slab comprising a step of plane- cutting the surface with the surface layer cutting device according to any one of claims 1 to 7 .

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