Remnant iron drilling bit

Abstract

To provide a bit for drilling a hole in residual pig iron that can easily remove a discontinuous portion of a continuous hole.SOLUTION: A bit 1 for drilling a hole in residual pig iron to drill residual pig iron of the present invention comprises a solid bit 110 and a cylindrical metal crown 120 inserted with the solid bit 110. A tip of the metal crown 120 is located ahead as compared to a tip of the solid bit 110. The metal crown 120 comprises an outer peripheral side metal crown 122 and an inner peripheral side metal crown 124. The outer peripheral side metal crown 122 has a wall thickness thinner than that of the inner peripheral side metal crown 124. A tip of the outer peripheral side metal crown 122 is located ahead as compared to a tip of the inner peripheral side metal crown 124.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a boring bit for boring pilot holes or the like into residual pig iron when performing a process for removing residual pig iron from a blast furnace. [Background technology]

[0002] When drilling residual pig iron in a blast furnace while attaching a drilling bit to the tip of a drilling machine rod and rotating the drilling bit integrally with the rod, the drilling bit wears out rapidly due to the nature of the residual pig iron and must be replaced frequently. For this reason, drilling bits that are as short as possible have conventionally been used to facilitate handling, such as replacement (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4693753 Summary of the Invention [Problem to be solved by the invention]

[0004] With conventional drilling bits, unevenness on the surface of the pig iron can cause the tip of the drilling bit to deviate from the target position, or the hardness of the pig iron is not uniform, causing the drilling bit to change course toward the side with lower hardness, making it difficult to drill through the remaining pig iron as expected.

[0005] As a result, even though the drilled holes are intended to overlap in order to form a continuous ring-shaped hole, the overlapping portion may disappear midway through the holes, resulting in a state in which the cutting line is not connected at the bottom of the hole. In this case, it is not possible to set the wire for cutting the bottom of the continuous ring-shaped hole in the predetermined position, and the pig iron lump cannot be removed.

[0006] Therefore, it is necessary to remove the disconnected parts of the continuous hole, but because the width is narrow, it is difficult to accurately cut them out with a conventional drill bit because the tip of the bit will shift.In addition, the depth can be more than 2m, making it difficult to cut them out with a lance whose tip burns when oxygen is supplied.

[0007] In view of the above, an object of the present invention is to provide a remnant iron drilling bit that can easily remove discontinuous portions of a continuous hole. [Means for solving the problem]

[0008] [1] In order to achieve the above object, the present invention provides: A remnant iron drilling bit for drilling remnant iron, Solid bits and A cylindrical metal crown into which the solid bit is inserted; Equipped with The tip of the metal crown is located further forward than the tip of the solid bit.

[0009] According to the present invention, the discontinuous portion can be cut so as to surround it with the metal crown that extends further than the solid bit, and then the discontinuous portion can be cut with the solid bit while being guided by the metal crown.

[0010] [2] In addition, in the present invention, the metal crown includes an outer circumferential metal crown and an inner circumferential metal crown, the outer circumferential metal crown is thinner than the inner circumferential metal crown, It is preferable that the tip of the outer peripheral metal crown is located further forward than the tip of the inner peripheral metal crown.

[0011] With this configuration, the outer metal crown, which is thinner than the inner metal crown, allows the blade to bite well when drilling begins, and the inner metal crown, which is thicker than the outer metal crown, suppresses vibration during drilling.

[0012] [3] In addition, in the present invention, the outer circumferential metal crown is integrally joined to the inner circumferential metal crown, It is preferable that the inner metal crown is integrally joined to the solid bit.

[0013] With this configuration, the metal crown can be rotated integrally with the solid bit by the power that rotates the solid bit.

[0014] [4] In addition, in the present invention, The solid bit is provided with a water supply hole, The outer circumferential metal crown is preferably provided with a plurality of slits spaced apart in the circumferential direction for discharging scraps of residual pig iron to the outside of the metal crown.

[0015] According to this configuration, water containing chips generated during drilling can be discharged from the metal crown through the slit.

[0016] [5] In addition, in the present invention, This is used to form a cut surface by forming a circular continuous hole in the residual iron, with multiple holes overlapping each other. The outer metal crown is installed in accordance with the range where the hole position is shifted and discontinuous, and an outer circumferential groove for guide is cut. the width of the outer peripheral groove is widened while the inner peripheral metal crown reinforces the outer peripheral metal crown; It is preferable to drill and remove the discontinuous hole portion with the central solid bit.

[0017] According to the present invention, discontinuous portions can be easily removed. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic longitudinal cross-sectional view showing a torpedo car with solidified pig iron ingots inside according to an embodiment of the invention. [Figure 2] Schematic longitudinal cross-sectional view showing the state in which continuous holes are formed in a pig iron ingot. [Figure 3] FIG. 10 is a schematic top view showing a state in which continuous holes and enlarged holes have been formed. [Figure 4] FIG. 10 is a schematic vertical cross-sectional view showing a state in which cutting is being performed with a wire saw. [Figure 5] Schematic vertical cross-sectional view showing the state of pulling up a pig iron ingot. [Figure 6] FIG. 2 is an explanatory diagram showing a residual iron drilling bit according to the present embodiment. [Figure 7] FIG. 2 is an explanatory diagram showing an exploded view of the residual iron drilling bit of the present embodiment. [Figure 8] FIG. 2 is an explanatory diagram showing a solid bit according to the embodiment. [Figure 9] FIG. 4 is an explanatory diagram showing a discontinuous portion of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] A remnant iron perforating bit according to an embodiment of the present invention will be described with reference to the drawings. Referring to Figures 1 and 2, the remnant iron perforating bit 1 (see Figure 2) of this embodiment is used to regenerate the torpedo car 10, which is also called a torpedo car (TPC) because of its torpedo-shaped exterior, by dismantling and discharging solidified pig iron ingots A inside the torpedo car 10 without damaging the torpedo car 10 as much as possible, thereby making the torpedo car 10 usable again.

[0020] The torpedo car 10 is used in steelworks to transport molten iron from the blast furnace plant to the steelmaking plant, and during transportation, it undergoes preliminary treatments such as desiliconization, dephosphorization, and desulfurization to remove impurities from the molten iron.

[0021] The torpedo car 10 is composed of a furnace body 11, which is a container for storing molten pig iron, a rotating device 12 for rotating the furnace body 11 when discharging the molten pig iron from the furnace body 11, and a bogie 13 for supporting the furnace body 11 and the rotating device 12. The outer shape of the furnace body 11 resembles a torpedo, and hence the torpedo car 10 is also called a torpedo car. Although not shown, the torpedo car 10 runs on a track by, for example, being towed by a locomotive (not shown).

[0022] The furnace body 11 is mainly composed of a steel shell 14, the outer shape of which is formed by joining steel plates by welding or other methods, and refractory material 15, such as firebricks, lining the inner surface of the steel shell 14. The ends of the furnace body 11 are supported by bearings of a rotating device 12, and the furnace body 11 is configured to rotate around its longitudinal axis by the rotating device 12. An opening 16, which is elliptical in top view and functions as a furnace port for inlet and outlet of molten iron, is provided in the center of the furnace body 11.

[0023] When a steelworks or the like is forced to suspend operations for an extended period of time to ensure safety due to a power outage or the like, the molten iron contained inside the furnace body 11 of the torpedo car 10 solidifies and becomes a pig iron lump A. Note that a portion A1 of the pig iron lump A indicated by a two-dot chain line in Fig. 1 is a portion that will be cut and removed as described below.

[0024] The method for recycling the torpedo car 10 used in this embodiment involves removing the pig iron lump A from the inside of the torpedo car 10. This method for recycling the torpedo car 10 includes a continuous hole forming step, an enlarged hole forming step, a cutting step, and a pulling-up step.

[0025] First, referring to Figures 2 and 3, we will explain the continuous hole forming process, in which a continuous continuous hole 31 is formed in the pig iron block A through the opening 16 using a hole drilling device 20 so as to surround the entire inner part when viewed from above.

[0026] In this continuous hole forming process, holes extending vertically from the top surface of the pig iron ingot A to a predetermined depth toward the bottom are sequentially formed using a hole drilling device 20 in the pig iron ingot A, the top surface of which is exposed through the opening 16. Adjacent holes are formed so as to be continuous and partially overlap each other. This forms continuous holes 31 that completely surround the inner portion when viewed from above. The continuous holes 31 are formed to the same depth, reaching near the bottom of the pig iron ingot A, without damaging the refractory 15 located at the bottom of the furnace body 11.

[0027] Here, the continuous holes 31 are formed in a circular ring shape when viewed from above in the pig iron ingot A. However, the continuous holes 31 are not limited to a circular shape when viewed from above, and may be, for example, an elliptical ring shape along the opening 16, or may have other shapes such as a polygonal ring shape.

[0028] Alternatively, the opening 16 may be enlarged by removing a portion of the shell 14 or the refractory material 15 near the opening 16, and then the continuous hole 31 may be formed through the opening 16. In this case, the portion of the shell 14 or the refractory material 15 that is closer to the center of the opening 16 than the cylindrical shell 14 that defines the opening 16 may be removed over the entire vertical direction. This increases the volume of the pig iron ingot A1 that can be removed in the pulling process, but requires repair of the removed portion of the shell 14 and the refractory material 15.

[0029] It is preferable to use, for example, a known drilling device 20 for drilling holes in solidified pig iron or steel as the drilling device 20. The drilling device 20 may be installed, for example, on a work platform that is approximately the same height as the upper end of the torpedo car 10 and can travel thereon.

[0030] The drilling device 20 is a crawler-type running body 21 equipped with a drilling device 22. Here, a guide support 24 is attached to the tip of a swivel arm 23 installed on the running body 21, and a drilling machine 25, which drills holes by rotational force, moves forward and backward along this guide support 24.

[0031] The drilling machine 25 is equipped with a motor 26 slidably mounted on the guide support 24, and this motor 26 has a mechanism for rotating a hollow rod 27. Water is supplied to the end of the hollow rod 27 on the motor 26 side, and this supplied water passes through the hollow rod 27 and is discharged from a water supply hole 112 of the remnant pig iron drilling bit 1 provided at the tip of the hollow rod 27. This water blows away crushed powder when the remnant pig iron drilling bit 1 drills the pig iron ingot A using the rotational force of the remnant pig iron drilling bit 1. At the same time, the water cools the remnant pig iron drilling bit 1, which becomes hot due to friction with the pig iron ingot A, thereby maintaining drilling performance.

[0032] 3 and 4, an enlarged hole forming process is carried out to form enlarged holes 32 that are enlarged in at least one direction, either inward or outward, of the circular ring shape in top view in at least one, preferably two, of the continuous hole 31 formed in the pig iron ingot A. These enlarged holes 32 are large enough to allow pulleys 42A and 42B of a wire saw 40, which will be described later, to be inserted therein. Here, the enlarged holes 32 are formed around two points that are point-symmetrical about the center point of the circular ring-shaped continuous hole 31 in top view, but the enlarged holes 32 are not limited to being formed at such positions.

[0033] Here, the enlarged hole 32 is formed to have a circular shape in top view that has a larger diameter than the individual holes (single holes 31a) that make up the continuous hole 31. Such an enlarged hole 32 can be formed by drilling using a larger-diameter bit 1 for the remnant iron drilling of the drilling machine 25 that was used when forming the single holes 31a of the continuous hole 31. However, the same drilling device 20, including the remnant iron drilling bit 1, that was used when forming the continuous hole 31 may be used to drill a plurality of holes that are partially overlapping, thereby forming an enlarged hole 32 that is not circular but has a rectangular shape in top view, for example.

[0034] Next, referring to Figure 4, pulleys 42A and 42B of the wire saw 40 described later are installed at the bottom of the two enlarged holes 32, respectively, and a cutting process is performed in which the pig iron block A is cut horizontally at the bottom of the continuous hole 31 using the wire saw 40.

[0035] The wire saw 40 mainly comprises a wire 41 (high-tensile steel wire) for cutting the workpiece, two pulleys 42A and 42B (grooved pulleys) around which the wire 41 is wound, tension rollers 43A and 43B arranged upstream and downstream of the pulleys 42A and 42B, respectively, to apply tension to the wire 41, and a wire motion mechanism 44 that causes the wire 41 to move in a circulating or reciprocating motion.

[0036] Using such a wire saw 40, a wire 41 is wound around pulleys 42A and 42B installed at the bottom of the two enlarged holes 32, and the wire 41 is moved in a circulating or reciprocating motion by a wire motion mechanism 44 installed on a work platform, thereby cutting the bottom half of the pig iron ingot A.

[0037] Specifically, initially, the wire 41 wound around the pulleys 42A and 42B is positioned in a semicircular arc along one side of the bottom of the continuous hole 32. When the wire 41 is circulated or reciprocated in this state, the wire 41 cuts the bottom of the pig iron ingot A in a horizontal direction, successively moving toward the center. As a result, the bottom of the pig iron ingot A is cut into a semicircular shape with the two enlarged holes 32 at both ends of the diameter.

[0038] Furthermore, the position where the wire 41 exists is positioned along the semicircular bottom on the opposite side of the continuous hole 31. Then, when the wire 41 is moved in a circulating or reciprocating motion in this state, the bottom on the opposite side of the pig iron ingot A is cut into a semicircular shape with the two enlarged holes 32 at both ends of the diameter.

[0039] In this way, the bottom surface of the pig iron ingot A is cut in two semicircular sections, and the cylindrical pig iron ingot A1 is separated from the surrounding pig iron ingot A. By cutting in two sections in this way, it is possible to shorten the length of the wire 41 compared to when the enlarged hole 32 is formed in only one place, and it is also possible to prevent delays in the cutting operation due to breakage of the wire 41.

[0040] During cutting with the wire saw 40, the wire 41 is sandwiched between the pig iron ingot A on both the top and bottom, but since cutting dust generated during cutting exists between the cut surfaces, the movement of the wire 41 is not inhibited to the extent that cutting by the wire 41 is not possible. After cutting by the wire saw 40 has progressed to a certain extent, a spacer or the like may be inserted into the gap formed at the bottom of the pig iron ingot A.

[0041] In this case, for example, a spacer is attached at a right angle to the tip of a bar that is longer than the distance from the top surface of the pig iron ingot A to the bottom end of the cut surface made by the wire saw 40. The spacer is inserted so that its longitudinal direction is aligned with the arc direction of the continuous hole, and when it reaches the bottom of the cut surface, the bar is rotated 90 degrees to insert the spacer between the cut surfaces made by the wire saw 40. By providing such spacers in several locations, the cut portion made by the wire saw 40 can be supported from the outside.

[0042] Furthermore, although the bottom of the pig iron ingot A is cut into semicircular shapes twice with the wire saw 40, there may be a portion remaining in the center when cutting is complete. In this case, the remaining portion can be removed by drilling a hole on the top surface and then cutting it. Alternatively, enlarged holes 32 may be formed in three or more locations, and pulleys 42A, 42B may be sequentially placed at the bottoms of two of these enlarged holes 32, so that the bottom of the pig iron ingot A is cut in three or more steps.

[0043] Next, referring to Fig. 5, a pulling-up process is performed in which the cut cylindrical pig iron lump A1 is pulled up onto the torpedo car 10. In this pulling-up process, the cylindrical pig iron lump A1, whose outer peripheral side surface has been cut across its entirety in the continuous hole forming process and whose bottom surface has been cut across its entirety in the cutting process, is separated by being pulled up onto the torpedo car 10 which has pig iron lump A remaining outside this pig iron lump A1.

[0044] At the start of the pulling-up process, a small portion of the pig iron ingot A1 that has not been cut may remain between the bottom surface of the cut pig iron ingot A1 and the pig iron ingot A2 remaining on the upper surface of the bottom of the torpedo car 10. The pig iron ingot A1 is pulled up using a pulling device 50 such as a large crane so that this remaining portion of the pig iron ingot A is broken by being torn off or ripped apart.

[0045] The torpedo car 10 from which the cut cylindrical pig iron lump A1 has been removed has no defects such as damage to the shell 14, and can be reused after removing the remaining pig iron lump A2. The removal of the pig iron lump A2 can be carried out by an appropriate method such as using a handheld melt cutting device (such as a lance) or a pig iron drill.

[0046] When pulling up the cut cylindrical pig iron ingot A1, it is preferable to install an anchor 51 in the cylindrical pig iron ingot A1 and use this anchor 51 to pull up the cylindrical pig iron ingot A1 with the lifting device 50. The anchor 51 may be installed in the cylindrical pig iron ingot A1 using a Chemical Anchor (registered trademark), which is formed, for example, in a hole on the top surface of the cylindrical pig iron ingot A1, a capsule containing a solvent inserted into the hole, and the anchor 51 is inserted into the hole to break the capsule with the anchor 51, causing a chemical reaction with the solvent to fix the anchor 51 to the pig iron ingot A1.

[0047] According to the method of this embodiment, as described above, since the bottom surface is cut by the wire saw 40 with the continuous hole 31 as the outer circumferential surface, the cylindrical pig iron lump A1 can be easily removed from the torpedo car 10. Furthermore, when cutting this portion of the pig iron lump A, no problems such as damage to the torpedo car 10 occur, and the torpedo car 10 can be successfully reused.

[0048] 6 to 9, the remnant iron drilling bit 1 of this embodiment includes a solid bit 110 and a cylindrical metal crown 120 into which the solid bit 110 is inserted. The metal crown 120 includes an outer circumferential metal crown 122 and an inner circumferential metal crown 124 disposed inside the outer circumferential metal crown 122 so as to overlap each other. Carbide tips are embedded in the tip of the outer circumferential metal crown 122 and the tip of the inner circumferential metal crown 124.

[0049] The thickness of the outer circumferential metal crown 122 is thinner than the thickness of the inner circumferential metal crown 124. The tip of the outer circumferential metal crown 122 is located further forward than the tip of the inner circumferential metal crown 124. The tip of the outer circumferential metal crown 122 is also located further forward than the tip of the solid bit 110. The tip of the inner circumferential metal crown 124 is set at the same position as the tip of the solid bit 110.

[0050] The outer metal crown 122 is integrally joined by welding to the inner metal crown 124. The inner metal crown 124 is integrally joined to the solid bit 110 by welding.

[0051] 8, the solid bit 110 is provided with a water supply hole 112. As shown in FIGS. 6 and 7, the outer circumferential metal crown 122 is provided with a plurality of slits 123 spaced apart in the circumferential direction for discharging residual pig iron chips to the outside of the metal crown 120.

[0052] Referring to Figure 9, the remnant iron drilling bit 1 is used to form a circular continuous hole 31 in the remnant iron by partially overlapping multiple single holes 31a. The remnant iron drilling bit 1 re-drills the area where the single holes 31a are misaligned and discontinuous (discontinuous portion 140) to make the holes continuous. The remnant iron drilling bit 1 is installed so that the outer metal crown 122 is positioned in line with the discontinuous portion 140, and cuts an outer peripheral groove 130 for guide. The outer metal crown 122 is reinforced by an inner metal crown 124. The inner metal crown 124 is cut to widen the outer peripheral groove 130 cut by the outer metal crown 122. The discontinuous portion 140 is then drilled and removed using the solid bit 110 located in the center.

[0053] According to the residual iron drilling bit 1 of this embodiment, the discontinuous portion 140 can be cut so as to surround it with the outer metal crown 122 that extends further than the solid bit 110, and then the discontinuous portion can be cut with the solid bit 110 while being guided by the metal crown 120.

[0054] Furthermore, because the thickness of the outer metal crown 122, whose tip extends further forward than the solid bit 110, is thinner than the thickness of the inner metal crown 124, the cutting edge of the outer metal crown 122 can bite well when drilling begins, allowing drilling to accurately begin from the desired position. Furthermore, the inner metal crown 122, which is thicker than the outer metal crown 122, can increase the overall thickness of the metal crown 120, making it less likely to deform due to reaction forces during drilling and suppressing vibration of the remnant iron drilling bit 1 during drilling. In particular, because the tip of the inner metal crown 122 and the tip of the solid bit 110 are in the same position, vibration of the remnant iron drilling bit 1 that occurs when the solid bit 110 drills remnant iron can be effectively suppressed.

[0055] Furthermore, since the solid bit 110, the inner metal crown 124, and the outer metal crown 122 are joined together, the power that rotates the solid bit 110 can also rotate the metal crown 120 as a unit.

[0056] The solid bit 110 is provided with a water supply hole 112, and the outer metal crown 122 is provided with a plurality of slits 123 spaced apart in the circumferential direction for discharging residual pig iron chips to the outside of the metal crown 120. This allows water containing chips generated during drilling to be discharged to the outside of the metal crown 120 through the slits 123.

[0057] The present invention is not limited to the methods specifically described in the above-described embodiments, and can be modified as appropriate within the scope of the claims. For example, the drilling device 20 may be only the drilling machine 25. Furthermore, compressed air may be supplied to the residual iron drilling bit 1 via the hollow rod 27 instead of water, and in this case, the same effect can be obtained. [Explanation of symbols]

[0058] 1 Residual iron drilling bit 10 Mixed iron car 11 Furnace body 12 Rotating device 13 Cart 14 Ironhide 15 Refractories 16 Aperture 20 Drilling equipment 21 Running body 22 Drilling device 23 Swivel arm 24 Guide Pillar 25 Drilling machine 26 Motor 27 Hollow Rod 31 Continuous hole 31a single hole 32 Enlarged hole 40 Wire Saw 41 Wire 42A, 42B pulleys 43A, 43B tension rollers 44 Wire motion mechanism 51 Anchor 110 Solid Bit 112 Water supply hole 120 Metal Crown 122 Outer metal crown 123 Slit 124 Inner metal crown 130 Peripheral groove 140 Discontinuous Parts A. Pig iron ingot A1 Part of pig iron block

Claims

1. A remnant iron drilling bit for drilling remnant iron, Solid bits and A cylindrical metal crown into which the solid bit is inserted; Equipped with A remnant iron drilling bit, characterized in that a tip of the metal crown is located further forward than a tip of the solid bit.

2. The remnant iron drilling bit according to claim 1, the metal crown includes an outer circumferential metal crown and an inner circumferential metal crown, the outer circumferential metal crown is thinner than the inner circumferential metal crown, A remnant iron drilling bit, characterized in that a tip of the outer peripheral metal crown is located further forward than a tip of the inner peripheral metal crown.

3. The remnant iron drilling bit according to claim 2, the outer circumferential metal crown is integrally joined to the inner circumferential metal crown, A remnant iron drilling bit, characterized in that the inner peripheral metal crown is integrally joined to the solid bit.

4. The residual iron drilling bit according to claim 2 or claim 3, The solid bit is provided with a water supply hole, a plurality of slits are provided at intervals in the circumferential direction in the outer metal crown for discharging scraps of the residual pig iron to the outside of the metal crown.

5. A residual iron drilling bit according to any one of claims 2 to 4, This is used to form a cut surface by forming a circular continuous hole in the residual iron, with multiple holes overlapping each other. The outer metal crown is installed in accordance with the range where the hole position is shifted and discontinuous, and an outer circumferential groove for guide is cut. the width of the outer peripheral groove is widened while the inner peripheral metal crown reinforces the outer peripheral metal crown; A residual iron drilling bit characterized in that the central solid bit drills and removes discontinuous hole portions.

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