EP0791661A2 - Tophole drill apparatus - Google Patents

Abstract

The machine incorporates a carriage with a protective shield (26) at its front end, and a separate guide mechanism for the drill (16), as well as drive means for moving the guide mechanism between working and rest positions. With the drill at rest, the guide mechanism is in a protected position. The machine comprises a) the drill guide mechanism and the drive means are accommodated in a compact, detacheable cassette (34) suspended at the front end of the carriage; b) the protective shield (26) is suspended in front of the cassette (34), and is provided with an opening (32) for the drill (16).

Description

The invention relates to a drilling machine for drilling holes in shaft furnaces, in particular blast furnaces.

Such drilling machines have been known for a long time. They include a carriage which is arranged in extensions of the tap hole. A drill drive is slidably arranged on the carriage. This drill drive rotates a tap hole drill, generates the feed and pulls the tap hole drill out of the tap hole. Such tap hole drills can be up to four meters long in large blast furnaces. They essentially comprise a smooth drill rod which carries a drill head at its front end. The rear end of the drill rod is clamped in a chuck of the drill drive.

At its front end, the mount has a protective shield that is covered with a fire-resistant material. The main function of the protective shield is to protect the carriage and the drill drive against the melt that shoots out of the drilled tap hole. In addition, the protective shield also fulfills a guiding function for the tap hole drill. The drill rod is guided in a guide hole in this protective shield.

When the tap hole is opened, the protective shield comes into regular contact with the melt. As a result, the protective shield is particularly stressed in the area of the guide hole, so that the guide hole in the protective shield no longer ensures correct guidance of the drill rod relatively quickly. In order to ensure proper guidance of the drill rod again, the protective shield must be replaced, although it would still fulfill its actual protective function.

From EP-A-0519397 a tap hole drilling machine is known which has separate guide means for the tap hole drill at its front end facing the blast furnace. These guide means are formed by two guide profiles made of steel or cast iron, each using a lever arm are pivotally attached to the carriage. A hydraulic or pneumatic cylinder attached to the carriage is connected to the two lever arms by means of a joint system, so that it can pivot the guide profiles laterally into a rest position from a working position in the drilling axis. In the working position, the two complementary guide profiles work together in such a way that they form a guide channel for a tap hole drill. In the rest position, however, the two guide profiles are on the side of the carriage behind a protective shield attached to the front of the carriage. In the device described in EP-A-0519397, the end-face protective shield only fulfills the function of protecting the two guide profiles in the rest position. Due to its wide cutout in the area of the drilling axis, the front shield can hardly protect the mount and the drill drive against the melt shooting out of the drilled tap hole. A protective shield in the area of the drilling axis has most likely been dispensed with to allow the mount to be brought closer to the tap hole for various work on the tap hole. It should also be emphasized that, despite the protective shield, the guide device at the end of the carriage represents an extremely exposed unit, so that damage cannot be completely ruled out. It must therefore be ensured that even serious damage to the guide device can be repaired quickly and does not cause the tap hole drilling machine to come to a standstill for too long. However, this guarantee does not apply to the tap hole drilling machine described above.

The object of the present invention is to largely eliminate or mitigate the aforementioned disadvantages of a tap hole drilling machine with a guide device known from EP-A-0519397.

This object is achieved by a tap hole drilling machine according to claim 1.

The tap hole drilling machine according to the invention comprises a mount which has at its front end a protective shield with a through opening for a tap hole drill, and separate guide means which directly are arranged behind the protective shield, and drive means for moving these guide means between a first position and a second position. The through opening in the protective shield of such a tap hole drilling machine no longer has to perform a guiding function for the tap hole drill. The guiding function for the tap hole drill is rather taken over by the separate guide means which, in a first position, form a guide for a tap hole drill in the axial extension of the through opening in the protective shield. The drive means make it possible to move these guide means into a second position, the guide means being in a protected position behind the protective shield in this second position. Since it is by no means necessary to guide the tap hole drill at the front end of the carriage until the end of the drilling process (i.e. until the drill pierces the melt), the guide means can thus be moved from the exposed guide position in an axial extension of the through opening protected position, behind the protective shield, before the drilling process is completed, i.e. before the melt shoots out of the drilled tap hole. This greatly reduces the risk that the guide means come into contact with the melt, and thus extends their service life. Since the through opening in the protective shield no longer has to perform a guiding function, slight to moderate wear of the protective shield in the region of the through opening hardly impairs the function of the protective shield. The protective shield therefore has to be replaced less frequently. According to the invention, the guide and drive means are combined in a compact, removable cassette which is suspended from the front end of the carriage. In the event of major damage, the front guide device can therefore simply be detached as a compact unit and replaced, for example, by a reserve unit. If the guiding device at the end of the carriage is more of a hindrance when carrying out various work on the tap hole, it can also be removed quickly. The protective shield is advantageously attached to the cassette and secured to it. The protective shield can therefore be easily dismantled without the entire cassette having to be dismantled. This makes it possible, for example, to quickly replace one protective shield with another, or to remove the protective shield if it is not absolutely necessary when using the tap hole drilling machine, but rather a hindrance, with residual protection for the guide means with their drive through the cassette remains.

There are many different ways to design the leadership tools. For example, they can be designed as a one-armed, hinged gripper that is pivoted laterally upwards into a protected position behind the protective shield. In a simple, yet extremely effective embodiment, the guide means comprise two pivotable arms, each of which has a guide profile at its free end. In the first position of the guide means, the two guide profiles work together in such a complementary manner that they form a guide hole, or a guide channel, for a tap hole drill. The guide profiles can be, for example, angle profiles that form a square guide hole for a tap hole drill.

The drive means advantageously have two levers to which the arms are screwed. It should be emphasized that the arms with guide profiles are relatively inexpensive to produce guide means, which are also easy to replace and consequently represent extremely economical wear parts.

The tap hole drilling machine advantageously has control means which, as a function of the position of a displaceable drilling drive, actuate the drive means in such a way that the guide means are moved from the working position into the rest position before the tap hole is completely drilled out.

Advantageous embodiments of the invention are described with reference to the accompanying drawings.

• Figur 1, eine Seitenansicht des vorderen Endes einer Bohrlafette mit einer eingehängten Führungsvorrichtung, in Bohrstellung vor einem Abstichloch eines Hochofens;
• Figur 2, einen Längsschnitt entsprechend der Schnittlinie A-A der Figur 1, wobei die Führungsvorrichtung in einer Arbeitsstellung gezeigt ist;
• Figur 3, einen Längsschnitt entsprechend der Schnittlinie A-A der Figur 1, wobei die Führungsvorrichtung in einer Ruhestellung gezeigt ist;
• Figur 4, ähnlich wie in Figur 2, einen Längsschnitt durch eine alternative Ausgestaltung der Führungsvorrichtung in einer Arbeitsstellung;
• Figur 5, ähnlich wie in Figur 3, einen Längsschnitt durch die alternative Ausgestaltung der Führungsvorrichtung nach Figur 4 in einer Ruhestellung.

Show it:

• Figure 1 is a side view of the front end of a drill carriage with a suspended guide device, in the drilling position in front of a tap hole of a blast furnace;
• Figure 2 shows a longitudinal section along the section line AA of Figure 1, wherein the guide device is shown in a working position;
• Figure 3, a longitudinal section along the section line AA of Figure 1, wherein the guide device is shown in a rest position;
• Figure 4, similar to Figure 2, a longitudinal section through an alternative embodiment of the guide device in a working position;
• Figure 5, similar to Figure 3, a longitudinal section through the alternative embodiment of the guide device according to Figure 4 in a rest position.

FIG. 1 shows the front end of a drill carriage 10, which is arranged in front of a tap hole 12 in the drilling position. This drilling mount 10 is part of a tap hole drilling machine known per se, as is used for drilling the tap hole 12 of a blast furnace (indicated by a blast furnace armor 13 in FIG. 1). The reference number 14 shows the head end of a tap hole drill, which essentially consists of a up to four meter long cylindrical drill rod 16 (diameter about 4 cm) and a drill head 18. The rear end, not shown, of the drill rod 16 is clamped in a chuck of a drill drive (not shown). This drill drive sets the tap hole drill 14 in rotation, generates the feed necessary for drilling and pulls the tap hole drill 14 out of the borehole. For this purpose, the drilling drive can be moved along the carriage 10. The mount is advantageously supported on the blast furnace armor 13 in the drilling position by means of a hook 20.

The reference number 22 shows a guide device for the tap hole drill at the front end of the mount 10. This guide device 22 is suspended as a compact, cassette-shaped unit by means of bolts 24 at the front end of the mount 10. It can therefore be easily assembled and disassembled as a compact unit.

It can be seen from FIG. 1 that the guide device 22 comprises a protective shield 26 on the end facing the tap hole. The latter essentially consists of a metallic support plate 28 with a Coating or lining 30 of a refractory mass. The function of this protective shield 26 is to protect the front end of the mount 10 and the drill drive when the tap hole drill breaks through into the melt against the melt shooting out of the drilled tap hole. As indicated by broken lines in FIG. 1, the protective shield 26 has a through opening 32 for the tap hole drill 14. Since this passage opening 32 naturally means a weak point in the protective shield 26 for the tap hole drill 14, its diameter should only be a few millimeters larger than the diameter of the drill rod 16.

Directly behind the protective shield 26, the guide device 22 has a cassette 34 with the guide means. Drive means 36 for the guide means are arranged above the cassette 34. These drive means 36 are protected against melt splashes by a removable sheet metal housing 38 on the furnace side.

In Figure 2 the outline of the protective shield 26 is indicated with dashes. It can be seen that the protective shield 26 is slightly larger than the cassette 34 with the guide means. The latter comprises two plates 40 ', 40' 'which are connected by means of spacers, such as the pipe socket 42, in such a way that they form a cavity between them. In Figure 2, only the rear plate 40 'is shown.

Both plates 40 ', 40' 'have lateral, upwardly open hooks 44', 46 ', which are axially one behind the other (the hooks in plate 40' 'are not shown in the figures). Two axially successive hooks each form a support for a support bolt 48, 50 of the protective shield 26. These support bolts 48, 50 are perpendicular to the protective shield 26 and are secured behind the plate 40 'against axial displacement. In FIG. 3, for example, washers and locking pins are indicated as securing means.

Two arms 56 ', 56''are arranged symmetrically to a central axis 57 between the plates 40', 40 ''. These arms 56 ', 56''bear on their lower one End that protrudes from the cassette 34, a respective guide profile 58 ', 58''. In the position shown in FIG. 2, two opposing angle profiles 58 ′, 58 ″ define a guide channel with a square cross section for the drill rod 16, in the axial extension of the through opening 32 in the protective shield 26. Each of the two arms 56 ′, 56 ″ is screwed onto a lever 62 'or 62''by means of screws 60. Elongated holes 64 allow centering of the guide profiles 58 ′, 58 ″ relative to the drilling axis 65. The two levers 62 ′ and 62 ″ are rotatably mounted on a common axis of rotation 66. The center axis of this axis of rotation 66 is parallel to the drilling axis 65. The aforementioned center axis 57 intersects the center axis of the axis of rotation 66 and the drilling axis 65.

Each of the levers 62 'and 62' 'is connected to an actuating cylinder 68' and 68 '', respectively. These are preferably pneumatic cylinders. They are attached to a support frame 70 to which the cassette 34 with the guide means is also attached. As already indicated above, the support frame 70 is hooked into the front end of the drilling mount 10 by means of the bolts 24.

In FIG. 2, the pistons 71 ', 71' 'of the actuating cylinders 68', 68 '' are extended. The same pistons 71 ', 71' 'are retracted in FIG. When the pistons 71 ', 71' 'were retracted, the levers 62', 62 '' were pivoted upwards. The guide profiles 58 ', 58' 'and the arms 56', 56 '' are now in a protected position at a relatively large distance from the through opening 32 in the protective shield 26, so that the melt jet and melt spatter can no longer harm them.

For mounting the tap hole drill 16, the arms 56 ', 56''preferably have moved apart, that is to say assume the position shown in FIG. 3. The carriage 10 is in a parking position to the side of the tap hole 12. The drill rod 16 is inserted from the front through the through opening 32 in the protective shield 26 and clamped in the chuck of the drill drive. Alternatively, the through opening 32 could, however, also be designed as a slot, so that the drill rod 16 is not with its whole Length must be inserted through the through opening 32 (see Figures 4 and 5). The arms 56 ', 56''are then pivoted into the position shown in FIG. 2 by actuating the actuating cylinders 68', 68 '', in which the drill rod 16 is correctly guided between the two guide profiles 58 ', 58''. The carriage 10 is brought into the drilling position and the drilling drive is switched on. The drill rod 16 rotates between the two guide profiles 58 ′, 58 ″, the latter, together with the chuck at the rear end of the drill rod 16, fixing the drilling axis properly and preventing the drill head 18 from swerving to the side. The drill head 18 penetrates the hardened stuffing compound. After approximately half of the tap hole channel has been drilled, the risk that the tap hole drill 14 will laterally swerve is extremely small, so that the front guide device is no longer required. A control device, indicated schematically in FIG. 3 by block 100, controls the actuating cylinders 68 ', 68''in such a way that the arms 56', 56 '' with the guide profiles 58 ', 58''are pivoted into the protected position is shown in Figure 3. For this purpose, the control device can have, for example, a switching element 102 which is arranged along the mount 10 and is actuated by the drilling drive as soon as it drives past a fixed position of the mount in the direction of the tap hole. It should be noted that when the drilling drive is retracted, the arms 56 ', 56''with the guide profiles 58', 58 '' remain in their protected position.

By pivoting the arms 56 ', 56' 'with the guide profiles 58', 58 '' back into the protected position before the tap hole is completely drilled out, the risk of the guide means coming into contact with the melt is greatly reduced and thus their service life extended. Since the through opening 32 in the protective shield 26 no longer has to perform a guiding function, slight to moderate wear of the protective shield 26 in the region of the through opening 32 hardly affects the function of the protective shield 26. The protective shield 26 must therefore be replaced less frequently.

From Figure 3 it can still be seen that after removal of the protective shield 26, the guide device 22 is in no way a hindrance if the tap hole drilling machine is used in between to insert a tapping rod into the not yet hardened stuffing compound or to pull out such a tapping rod from the hardened stuffing compound. The large cutout 80 in the lower part of the plates 40 'and 40''allows a relatively easy and clear approach of the carriage end to the free end of the tapping rod in the hardened stuffing compound. The guide means 56 ', 58', 56 '', 58 '' are nevertheless in a protected position behind the plate 40 ''.

An alternative embodiment of the drive means is shown in FIGS. 4 and 5. It can be seen that the two arms 156 ', 156' 'are arranged symmetrically to a central axis 57 in a cross. These crossed arms 156 ', 156' 'each carry a previously described guide profile 58', 58 '' at their lower end, which protrudes from the cassette 34 in FIG. Each of the two arms 56 ', 56' 'is screwed onto a lever 162' or 162 '' by means of screws 160. The two levers 162 'and 162' 'are each rotatably mounted on their own axis of rotation 166', 166 '', so that each lever 162 ', 162' 'forms a double-armed lever. A link 167 and an actuating cylinder 168 connect the lever arms of the levers 162 'and 162' 'to form a transmission. In Figure 4, the piston of the actuating cylinder 168 is retracted. The guide means are in their working position. When the piston of the single actuating cylinder 168 is extended, the arms 156 ′, 156 ″ are pivoted upwards in a cross manner, as can be seen from FIG. 5.

Comparing FIG. 5 with FIG. 3, it can be seen that in the embodiment according to FIG. 5 the swivel tracks 169 ', 169''of the guide profiles 58', 58 '', with approximately the same length of the arms 156 ', 156''and the Arms 56 ', 56''have a much smaller diameter than the swivel tracks 69', 69 '' of the guide profiles 58 ', 58''in the embodiment according to FIG. 3. In other words, the guide profiles in the embodiment according to FIG 58 ', 58''can be pivoted much further outwards in order to be raised to the same height relative to the carriage as in the embodiment according to FIG. 3. The crossed arms 156 ', 156''make the guide device more compact in its rest position, which has a favorable effect on the versatility of the tap hole drilling machine.

Claims (10)

Tap hole drilling machine comprising: a mount (10) which can be aligned in front of the tap hole (12) of a shaft furnace, the front end of the mount (10) having a protective shield (26), separate guide means for a tap hole drill (16) which are arranged immediately behind the protective shield (26), and Drive means for moving these guide means between a working position and a rest position, the guide means forming a guide for a tap hole drill (16) in the working position, and the guide means being in the protected position behind the protective shield (26), characterized in that that the guide and drive means are combined in a compact, removable cassette (34) which is suspended at the front end of the carriage (10), and that the protective shield (26) is attached to the front end of this cassette (34) and has a through opening (34) for a tap hole drill (16). Tap hole drilling machine according to claim 1, characterized in that the cassette (34) has a front end plate (40 '), the protective shield (26) being larger than this front end plate (40'). Tap hole drilling machine according to claim 2, characterized in that in the rest position, the guide means are in a protected position behind the front end plate (40 '). Tap hole drilling machine according to one of claims 1 to 3, characterized in that the guide means comprise two pivotable arms (56 ', 56'',156', 156 ''), each of which has a guide profile (58 ', 58 at its free end ''), the two guide profiles (58 ', 58'') working together in the working position of the guide means such that they form a guide hole for a tap hole drill in the axial extension of the through opening (32) in the protective shield (26). Tap hole drilling machine according to claim 4, characterized in that the guide profiles are angle profiles (58 ', 58' '). Tap hole drilling machine according to one of claims 1 to 5, characterized in that the drive means have two levers (62 ', 62' ', 162', 162 '') on which the arms (56 ', 56' ', 156', 156 '') are screwed tight. Tap hole drilling machine according to one of claims 4 to 6, characterized in that the two pivotable arms (156 ', 156' ') are arranged in a crossed manner. Tap hole drilling machine according to one of claims 1 to 7, characterized by a drill drive which is displaceable along the mount (10) and by control means (100, 102) which actuate the drive means in function of the position of the drill drive along the mount (10), such that the guide means are moved from the working position to the rest position before the tap hole is completely drilled out. Tap hole drilling machine according to one of claims 1 to 8, characterized in that the through opening (34) for a tap hole drill (16) in the protective shield is slot-shaped. Tap hole drilling machine according to one of claims 1 to 9, characterized in that the protective shield comprises a metallic support plate (28) with a coating or lining (30) made of a refractory mass, and two supporting bolts (48, 50).

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