JP5377013B2 - Short side structure of continuous casting mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a short side edge part structure of a continuous casting mold having small thickness of a short side, the structure suppressing sliding flaws occurring when the short side is slid for changing the casting width. <P>SOLUTION: A pair of long sides 10, 11 are arranged opposite to each other, and a pair of slidable short sides 12, 13 are arranged between the long sides 10, 11 so as to be opposite to each other, further, long side back plates 14, 15 and short side back plates 16, 17 are arranged at the back faces of the long sides 10, 11 and the short sides 12, 13, respectively, and dovetail grooves 32 extending from the upper edge to the lower part of the side edge parts 30, 31 are formed over the respective side edge parts 30 of the short sides 12, 13 and the respective side edge parts 31 of the short side back plates 16, 17 corresponding to both the side edge parts 30. Further, heat resistant cushion material 33 having lubricity is attached to the dovetail groove 32 in a state of receiving holding power from the long sides 10, 11 so as to be projected from the side faces 38 of the short sides 12, 13. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a short-side end structure of a continuous casting mold capable of suppressing sliding flaws that can be generated by changing the casting width.

In a continuous casting mold having a pair of long sides and a pair of short sides arranged oppositely between the long sides and being sandwiched between the long sides, if the pair of short sides is made slidable, manufacturing The width of the cast slab can be changed.
In this case, since both end portions of each short side that are in contact with the long side receive a clamping force from the long side, sliding the short side may cause a sliding wrinkle on the long side.
Therefore, in order to suppress the occurrence of this sliding wrinkle, it has been proposed to attach a heat-resistant cushioning material having lubricity to both ends of the short side sandwiched by the long side (see Patent Document 1).

In the short side end portion of the continuous casting mold described in Patent Document 1, a concave groove extending in the casting direction is formed at both ends of the short side, and a heat-resistant cushioning material is attached to the concave groove.
If the heat-resistant cushioning material has low frictional resistance, the frictional resistance generated at the contact portion between the short side and the long side when sliding on the short side is small, and the sliding wrinkles generated on the long side are Can be suppressed.
Further, the heat-resistant cushioning material is excellent in heat resistance, and the characteristic that the frictional resistance is low even at high temperatures is not impaired, and sliding wrinkles can be suppressed.
The heat-resistant cushioning material has a concave groove formed at a side end portion having a certain distance from the inner surface of the short side which is a contact surface with the molten steel so as not to directly touch the molten steel.

JP-A 63-2536

In the continuous casting mold described in Patent Document 1, the groove to which the heat-resistant cushioning material is attached is formed so that the entire groove is located inside the side surface of the short side. It becomes narrower than the thickness.
In addition, since the short side is thermally deformed on the inner surface and its vicinity due to the heat of the molten steel, it is necessary to arrange a heat-resistant cushioning material at a position not affected by the thermal deformation. It is necessary to form the groove with a certain distance from the inner surface.
Therefore, the maximum width of the heat resistant cushioning material is a value obtained by subtracting this constant distance from the thickness of the short side.
On the other hand, in continuous casting molds using electromagnetic force, it is often required to narrow the thickness width of the short side in order to attenuate the electromagnetic force or reduce the temperature generated in the short side by continuous casting.
Here, the surface pressure that the heat-resistant cushioning material receives per unit area is proportional to the holding force received from the long side and inversely proportional to the size of the area of the heat-resistant cushioning material. If the surface area is reduced by narrowing the surface pressure, the surface pressure increases.

The heat-resistant buffer material has an inherent allowable surface pressure depending on the heat-resistant resin constituting the heat-resistant buffer material, and damage or the like may occur when the surface pressure is larger than the allowable surface pressure.
Therefore, the form in which the heat-resistant cushioning material is arranged in the grooves formed in both side surfaces of the short side is a continuous casting mold with a narrow width of the short side, and the width that can be secured for the heat-resistant cushioning material is narrowed, The area of the joint surface with the long side of the cushioning material is also reduced, and the surface pressure received by the heat resistant cushioning material is increased.
That is, when the width of the heat-resistant cushioning material becomes narrow and the surface pressure received by the heat-resistant cushioning material exceeds the allowable surface pressure, this conventional heat-resistant cushioning material arrangement form cannot be applied.
Therefore, an object of the present invention is to provide a short-side end structure of a continuous casting mold that can suppress sliding wrinkles even when the thickness width of the short side is narrow in the continuous casting mold.

The short-side end structure of the continuous casting mold that meets the above-mentioned purpose has a pair of long sides supported by a back plate and a pair of short sides that are slidably disposed facing each other. In the short-side end structure of the casting mold, a groove is formed across the short plate and the back plate disposed on the back surface of the short side, and the heat-resistant cushioning material having lubricity disposed in the groove is, The heat-resistant cushioning material protrudes from the side surface of the short side in a state of receiving a clamping force from the long side.
In the short side end structure of the continuous casting mold according to the present invention, the groove is a dove groove widened from the entrance side to the back side, and the heat-resistant cushioning material has wear resistance, and the heat-resistant buffer It is preferable that the cross section of the material is a heat resistant resin having a shape that fits into the dovetail groove.

In the short-side end structure of the continuous casting mold according to the present invention, the heat-resistant resin is a fluororesin or a metal powder mixed with a fluororesin, and a surface pressure due to a clamping force received from the long side is 15 MPa. The following is preferable.
In the short-side end structure of the continuous casting mold according to the present invention, the width of the short side is wider in the range of 0.8 to 4 mm than the width of the back plate supporting the short side, It is preferable to project within a range of 0.2 to 1 mm from the side surface of the short side in a state where no clamping force is received from the long side.

In the short-side end structure of the continuous casting mold according to the present invention, the bottom of the heat-resistant cushioning material is flat, and is formed on the bottom surface formed on the short side of the dovetail groove and on the back plate side of the short side. When the bottom surface to be formed is not located on the same plane, it is preferable to arrange a shim made of a metal plate on the bottom surface located far from the entrance side of the dovetail groove.
In the short side edge part structure of the continuous casting mold according to the present invention, the thickness of the short side may be in the range of 10 to 30 mm.

The short-side end structure of the continuous casting mold according to claim 1, wherein the heat-resistant cushioning material disposed in the groove formed across the back plate disposed on the back surface of the short side and the short side is the long side. Because it protrudes from the side surface of the short side while receiving the clamping force from, it is possible to place a wide heat-resistant cushioning material even in a continuous casting mold with a narrow width of the short side, and tolerate the surface pressure that the heat-resistant cushioning material receives The surface pressure can be reduced to less than the surface pressure, and the use of a heat-resistant cushioning material having lubricity makes it possible to reduce the occurrence of sliding wrinkles.

In particular, the short-side end structure of the continuous casting mold according to claim 2 is a dove groove in which the groove for disposing the heat-resistant buffer material is widened from the entrance side to the back side, and the cross-section of the heat-resistant buffer material is Since the heat-resistant resin is shaped to fit into the dovetail groove, it is possible to prevent the heat-resistant cushioning material disposed across the short side and the back plate from dropping from the mold.
In addition, since a material having wear resistance is used as the heat-resistant cushioning material, it can be used to prevent sliding wrinkles over a long period of time, and the frequency of replacement and repair of the heat-resistant cushioning material can be reduced.

4. The short-side end structure of the continuous casting mold according to claim 3, wherein the fluororesin is excellent in wear resistance, heat resistance and lubricity, so that it is suitable for use at a high temperature and has a frictional resistance generated between the long side and the long side. And the generation of sliding wrinkles due to sliding on the short side can be suppressed. In particular, a fluororesin or a tetrafluoroethylene-based resin, such as Teflon (registered trademark), which has a heat resistance of about 400 ° C. and also has a lubricating function, can be used as the heat-resistant resin.
Moreover, what mixed the metal powder in the fluororesin can enlarge the intensity | strength with respect to a shear compared with the case where the metal powder is not mixed.
Further, since the surface pressure generated by the clamping force received from the long side is 15 MPa or less, it is possible to prevent damage or the like of the fluororesin or the heat resistant resin in which the metal powder is mixed in the fluororesin.

The short side edge structure of the continuous casting mold according to claim 4, wherein the width of the short side is wider in a range of 0.8 to 4 mm than the width of the back plate supporting the short side, and the heat resistant cushioning material is from the long side. Since it protrudes in the range of 0.2 to 1 mm from the side surface of the short side without receiving the holding force, each short side and each back plate is not affected even if the heat-resistant cushioning material receives the clamping force from the long side. The heat-resistant cushioning material can be protruded from the side surface of the short side so as not to be joined directly to the long side.

6. The short side edge structure of the continuous casting mold according to claim 5, wherein the bottom surface formed on the short side of the dovetail groove and the bottom surface formed on the back plate side are not located on the same plane, and the dovetail entrance Since the shim made of a metal plate is disposed on the bottom surface located far from the side, the heat-resistant cushioning material can be stably attached to the groove.

In the short side edge structure of the continuous casting mold according to claim 6, even if the thickness of the short side is in the range of 10 to 30 mm, the width of the heat resistant cushioning material is not limited by the thickness of the short side. It is possible to secure a width necessary for the surface pressure received by the cushioning material to fall within a range that does not cause damage to the heat-resistant cushioning material.

It is a top view of the continuous casting mold which has the short side edge part structure of the continuous casting mold which concerns on one embodiment of this invention. It is a partially omitted front sectional view of the continuous casting mold. (A) is a front view of the short side of the continuous casting mold, and (B) is a side view of the short side and the short side back plate of the continuous casting mold. (A) is a plan view showing the short-side end structure of the continuous casting mold, and (B) and (C) are a state in which a heat-resistant cushioning material is attached to the short side and back plate of the continuous casting mold, respectively, and removal. It is explanatory drawing which shows the state shown.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.

As shown in FIGS. 1 and 2, a continuous casting mold having a short-side end structure of a continuous casting mold according to an embodiment of the present invention has a pair of long sides 10 and 11 facing each other, and A pair of slidable short sides 12 and 13 are arranged to face each other between the long sides 10 and 11.
Immediately after the long sides 10 and 11 and the short sides 12 and 13, the long side back plates 14 and 15 and the short side back plates 16 and 17 are the inner surfaces of the long sides 10 and 11, and the short sides 12 and 13, respectively. It arrange | positions so that it may contact | abut.
The long side back plates 14, 15 are provided with through holes at four locations on the top, bottom, left, and right, respectively, and tie rods 28 arranged over the long side back plates 14, 15 are inserted into the through holes. Both end portions of each tie rod 28 protrude from the back surfaces of the long side back plates 14 and 15.

A first nut 39 that abuts against the back surface of the long side back plate 14 is attached to one end portion of each tie rod 28 so as not to change the position relative to the end portion of the tie rod 28.
In addition, the expansion / contraction means 29 and the second nut 40 are attached to the other end of each tie rod 28 in order from the side closer to the back side of the long side back plate 15, respectively. The back surface of the plate 15 and the second nut 40 are in contact with each other, and the second nut 40 is fixed so that the position of the tie rod 28 to which the second nut 40 is attached does not change. As the expansion / contraction means 29, for example, a disc spring can be used.
With this configuration, the long side back plates 14 and 15 are tightened inward by the expansion and contraction means 29 extending and contracting in the longitudinal direction of the tie rod 28.
The long side back plates 14 and 15 may be tightened inward by another clamping mechanism instead of the tie rod 28.

Width change mechanisms 18 and 19 are arranged on the back surfaces of the short side back plates 16 and 17. The width changing mechanism 18 (the same applies to the width changing mechanism 19) has long hydraulic cylinders 22 and 23 that are connected to the upper and lower portions of the short side back plate 16 via connecting members 20 and 21, respectively. It is fixed to the support frame 25 by a prismatic support member 24.
The hydraulic cylinders 22 and 23 are each a long outer cylinder 26 that penetrates and is fixed at two upper and lower portions of the support member 24, and a rod that moves along the longitudinal direction of the outer cylinder 26 inside the outer cylinder 26. 27.

Each support member 24 is arranged so that its longitudinal direction is vertical, and the lower side of the support member 24 penetrates and is fixed to the support frame 25.
The hydraulic cylinders 22 and 23 move the rod 27 in the direction of the short side back plate 16 and press and move the short side 12 together with the short side back plate 16 in the direction of the short side 13 facing each other.
Also, the hydraulic cylinders 22 and 23 can move the rod 27 to move the short side 12 in the direction opposite to the direction in which the short side 13 is present, and the distance between the short sides 12 and 13 can be changed. .

As shown in FIGS. 3A and 3B, both side end portions 30 of short side 12 (the same applies to short side 13) and short side back plate 16 corresponding to each side end portion 30 (short side back plate). 17 also extends over the short side 12 and the short side back plate 16 and extends from the upper end to the lower side of the short side 12 and the short side back plate 16 and has a groove (an example of a groove) 32. A heat-resistant cushioning material 33 is attached to the dovetail groove 32.
The dovetail groove 32 is formed so that the upper ends of both the short side 12 and the short side back plate 16 are opened and the lower end is not opened, so that the heat resistant cushioning material 33 can be detached from the upper end and the attached heat resistant The downward cushioning material 33 is prevented from falling off.

4A, 4B, and 4C, the width of the short side 12 (the same applies to the short side 13) is wider in the range of 0.8 to 4 mm than the width of the short side back plate 16, The protruding length b in which the side surface 38 of the short side 12 (the plane disposed on the side end 30 in the direction perpendicular to the inner surface of the short side 12) protrudes from the short side back plate 16 is in the range of 0.4 to 2 mm. It has become. Moreover, the thickness of the short side 12 is the range of 10-30 mm. The width of the short side 12 is the distance between the side surfaces 38, and the thickness of the short side 12 is the distance between the inner surface and the back surface.
When the short side 12 and the short side back plate 16 are viewed from above, the dovetail groove 32 is widened from the entrance side to the back side of the formed groove, the width x of the bottom thereof is 20 mm or more, and the short side 12 The groove entrance (opening) is formed from a position having a distance y from the inner surface of the short side 12. The entrance side of the groove 32 of the dovetail groove 32 is the long side 10, 11 side, and the back side is the width direction center side of the short side 12.
Here, since the distance y is in the range of 5 to 10 mm, the inner surface of the short side 12 and the vicinity thereof are deformed by the heat of the molten steel, but the heat-resistant cushioning material 33 attached to the dovetail groove 32 is not deformed. Since it is not influenced, the same joining state can be maintained without changing the positional relationship between the long sides 10 and 11 and the heat-resistant buffer material 33 before and after deformation.

The cross-sectional shape in the horizontal direction of the heat-resistant cushioning material 33 is an isosceles trapezoid that fits into the dovetail groove 32, and its lower side is longer than the upper side and its length is the same as x or 0.5 mm or less from x. The range may be long or short. Further, since the slope from the upper side to the lower side of both sides of the isosceles trapezoid is the same as the slope rate from the entrance side to the back side of the groove 32, the heat-resistant cushioning material 33 has the clearance 32 in the groove 32. It can be securely installed without any problems.

The bottom surface 34 of the dovetail groove 32 is formed from two flat surfaces located on both sides of the short side 12 and the short side back plate 16. Here, when the plane located on the short side 12 side and the plane located on the short side back plate 16 side of the two planes forming the bottom surface 34 are not on the same plane, they are located far from the entrance side of the dovetail groove 32. Since a shim (not shown) made of a metal plate is disposed on the plane to be performed, a step between these two planes can be eliminated.
Therefore, even when there is a step between the short sides 12 forming the bottom surface 34 of the dovetail groove 32 and the short side back plate 16, the heat-resistant cushioning material 33 having a flat bottom is connected to the short side 12. It can be stably attached to the short side back plate 16.
Note that shims having different thicknesses may be arranged on both of the two planes forming the bottom surface of the dovetail so as to eliminate the step between these two planes.

The heat-resistant cushioning material 33 is between the upper surface (surface that forms the upper side of the trapezoidal cross section) 36 and the bottom surface (the surface that contacts the bottom surface 34 of the dovetail groove 32) 37 in a state where it does not receive the clamping force from the long sides 10 and 11. Is a range of 3 to 7 mm, and a protrusion length a from the side surface 38 of the short side 12 of the upper surface 36 to the long side 10 and 11 side (outside in the width direction of the short side 12) is 0.2 to 1 mm. It is attached to the dovetail groove 32 so that
The protrusion length a is within a range of 0.5 mm or less when the heat-resistant cushioning material 33 receives the clamping force from the long sides 10 and 11 by tightening the tie rod 28 and does not receive the clamping force. The distance between the upper surface 36 and the bottom surface 37 is adjusted so that the upper portion of the heat-resistant cushioning material 33 protrudes from the side surface 38 of the short side 12 even when receiving a clamping force.

Further, the heat-resistant buffer material 33 is made of Teflon (registered trademark), which is an example of a fluororesin that is a heat-resistant resin having wear resistance and heat resistance and excellent in lubricity.
Therefore, when the short side 12 slides while the heat-resistant cushioning material 33 receives the clamping force from the long sides 10 and 11, the side surfaces 38 of the short side 12 do not contact the long sides 10 and 11, and the heat-resistant buffer 33 Since the upper surface 36 of the material 33 contacts, the sliding wrinkles generated on the long sides 10 and 11 can be reduced by the excellent lubricity of the heat-resistant buffer material 33.
In addition, the heat-resistant buffer material 33 can also be made by mixing a metal powder, for example, a copper powder, into a fluororesin.
If metal powder is mixed, the strength against shearing can be increased as compared with the case where metal powder is not mixed.

The heat-resistant cushioning material 33 made of Teflon (registered trademark) has an allowable surface pressure of 30 MPa for side slip at room temperature (5-35 ° C.), but in a high-temperature environment where the heat-resistant cushioning material 33 is used (higher than room temperature). At a temperature (for example, 100 ° C.), this allowable surface pressure decreases.
Therefore, the index surface pressure, which is the maximum surface pressure within a range where the heat-resistant buffer material 33 is not damaged at a high temperature, is set to 15 MPa, which is half of the normal temperature value, and the surface pressure received by the heat-resistant buffer material 33 is as follows. It will be explained that the value is smaller than the index surface pressure.

The fastening force of the long sides 10 and 11 by the tie rod 28 is such that the molten steel does not leak from the four gaps formed by the inner surface of each of the long sides 10 and 11 and both end portions 30 of the short sides 12 and 13. It is necessary to make it larger than the pressure, and the total clamping force that each heat-resistant cushioning material 33 receives from the long sides 10 and 11 is a size obtained by subtracting the molten steel static pressure from the clamping force of the tie rod 28.
The surface pressure acting on each heat-resistant cushioning material 33 by the clamping force received from the long sides 10 and 11 is the same as that of each heat-resistant cushioning material 33 received from the long sides 10 and 11. It can be obtained by dividing by the area of the upper surface 36.

As shown in FIG. 3B, the shape of the upper surface 36 of the heat-resistant cushioning material 33 is a rectangle, and the length h of the rectangle is shorter than the height of the short side 12, so the height of the short side 12 is 900 mm. If present, h is a value less than 900 mm, for example, 850 mm.
In order for the clamping force applied to each heat-resistant buffer material 33 to be 200 kN and the thickness of the short side 12 to be 25 mm, the surface pressure generated in each heat-resistant buffer material 33 is less than 15 MPa, which is the index surface pressure. Is larger than the value obtained by dividing the pressing force 200 kN by the index surface pressure of 15 MPa. This is because the width z of the upper surface 36 is 15.7 mm (exactly, this value is 100 minutes for the value obtained by dividing 200 kN by 15 MPa. It means that it is sufficient if it is greater than or equal to 1) (z is shown in FIG. 4C).
Since each heat-resistant cushioning material 33 is attached across the short side 12 (the same applies to the short side 13) and the short side back plate 16 as described above, the upper surface 36 has a width wider than the thickness of the short side 12. Can do.
Therefore, the width z of the upper surface 36 can be secured to 15.7 mm or more, and the surface pressure received by the heat resistant buffer material 33 can be made smaller than the index surface pressure of 15 MPa.

On the other hand, in the conventional continuous casting mold (for example, the continuous casting mold described in Patent Document 1) attached so that the heat-resistant cushioning material is accommodated at both end portions of the short side, the heat-resistant cushioning material is not deformed by heat of the short side. Since it arrange | positions in the position which is not influenced, it is calculated | required to arrange | position a heat resistant shock absorbing material in the position which maintained the fixed distance from the inner surface of the short side which contact | connects molten steel.
Accordingly, it is necessary to make the width of the heat resistant cushioning material narrower than the thickness of the short side. If the height and thickness of the short side are 900 mm and 25 mm, respectively, the width of the heat resistant cushioning material is about 10 mm at the maximum. Become.
When the width of the heat-resistant cushioning material is 10 mm, when the holding force applied to each heat-resistant cushioning material is 200 kN, the surface pressure generated in each heat-resistant cushioning material is about 23.5 MPa. The value exceeds the index surface pressure of 15 MPa, that is, a value at which damage or the like can occur in the heat-resistant buffer material.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described form, for example, the thickness of the short side and the size of the heat resistant cushioning material. Instead of (registered trademark), other fluororesins having a heat resistance of about 400 ° C. and a lubricating function may be used, and tetrafluoroethylene resins may be used. Scope of application.

10, 11: Long side, 12, 13: Short side, 14, 15: Long side back plate, 16, 17: Short side back plate, 18, 19: Width changing mechanism, 20, 21: Connecting member, 22, 23 : Hydraulic cylinder, 24: support member, 25: support frame, 26: outer cylinder, 27: rod, 28: tie rod, 29: expansion / contraction means, 30: side end, 31: side end, 32: dovetail groove, 33 : Heat resistant cushioning material, 34: bottom surface, 36: top surface, 37: bottom surface, 38: side surface, 39: first nut, 40: second nut

Claims (6)

In a short side end structure of a continuous casting mold having a pair of long sides supported by a back plate and a pair of short sides slidably disposed between the long sides.
A groove is formed across the short plate and the back plate disposed on the back surface of the short side, and the heat-resistant cushioning material having lubricity disposed in the groove has the heat-resistant cushioning material from the long side. A short-side end portion structure of a continuous casting mold, wherein the structure projects from a side surface of the short side in a state of receiving a clamping force. 2. The short side end structure of the continuous casting mold according to claim 1, wherein the groove is a dove groove widened from the entrance side to the back side, and the heat-resistant cushioning material has wear resistance, and the heat resistance A short-side end structure of a continuous casting mold, characterized in that the cross-section of the cushioning material is a heat-resistant resin having a shape that fits into the dovetail groove. The short-side end structure of the continuous casting mold according to claim 2, wherein the heat-resistant resin is a fluororesin or a mixture of fluororesin with metal powder, and a surface pressure due to a clamping force received from the long side is A short-side end structure of a continuous casting mold, which is 15 MPa or less. The short side edge part structure of the continuous casting mold of any one of Claims 1-3 WHEREIN: The width | variety of the said short side is the range of 0.8-4 mm from the width | variety of the said back plate which supports this short side. Widely, the heat-resistant cushioning material protrudes within a range of 0.2 to 1 mm from the side surface of the short side in a state where it does not receive a clamping force from the long side. End structure. 4. The short-side end structure of the continuous casting mold according to claim 2 , wherein a bottom portion of the heat-resistant cushioning material is a flat surface, and a bottom surface formed on the short side of the dovetail groove and a back plate of the short side. If the bottom surface formed on the side is not located on the same plane, a short side of the continuous casting mold, wherein a shim made of a metal plate is disposed on the bottom surface far from the entrance side of the dovetail groove End structure. The short side edge part structure of the continuous casting mold of any one of Claims 1-5 WHEREIN: The thickness of the said short side exists in the range of 10-30 mm, The short side edge part of the continuous casting mold characterized by the above-mentioned. Construction.

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