EP0064644B1 - Guiding and positioning mechanism for the drill hammer of the taphole in a shaft furnace, and drilling device provided with this mechanism - Google Patents

Description

The present invention relates to a device for centering and guiding a drilling rod for the taphole of a shaft furnace designed to be mounted on the front end of the carriage mount of a taphole drilling machine which is equipped with a device for gripping the end of the piercing rod which can slide along the mounting of the machine. The invention also relates to a machine for drilling a tap hole equipped with such a centering and guiding device and suitable for a method according to which the opening and closing of the tap hole respectively comprise an extraction operation. and an operation to replace the piercing rod which is abandoned in the taphole between two successive castings.

This relatively recent method for opening the tap hole by means of a drilling rod which is abandoned in the tap hole between two successive castings is attracting growing interest at the expense of conventional methods consisting in drilling the tap holes using a drill bit. drilling. For more details concerning this process and its advantages, as well as for the necessary equipment, reference may be made to patent LU-A-82,943.

This patent also explains the problems linked to the use, for the implementation of this new process, of machines designed for the conventional drilling processes or to the design of machines suitable for the implementation of the two processes, namely the process conventional, or the drilling process mentioned in the preamble.

These problems result from the need for alignment between the piercing rod and the gripping device thereof, as well as from the need to "thread" the piercing rods through a guide and support device during the approach movement from the lookout to the operative position.

However, there are two factors to be taken into account which generally mean that these conditions are not met. Indeed, it may happen that the piercing rod after being replaced in the tap hole, in the plugging mass not yet hardened, bends or bends slightly under the influence of heat and its weight, which makes that its end, which must be gripped by the gripping device of the drilling machine, is slightly offset from the axis of the tap hole and the axis of this gripping device.

Another factor to be taken into account is that of the type of machines used and more particularly the approach path to the lookout. Indeed, so that the device or the guide and support head located at the front of the carriage can be threaded onto the end of the piercing rod, it is necessary that the final phase of the approach movement of the carriage evolves appreciably in the axis of the piercing rod. However, this condition is rarely fulfilled for a machine designed for a conventional drilling process. Indeed, many of these machines are designed to bring the carriage into the working position by means of a double movement, the last phase of which is necessary for the final and exact positioning in alignment with the tap hole is always a substantially vertical movement parallel to the wall. from the oven. It is obvious that such a movement does not allow the engagement of the guide head at the front of the mount in the protruding end of the piercing rod when the latter is firmly anchored in the hardened mass of the hole. of casting. To allow this engagement of conventional drills in the drilling rod, it was until now, at each operation, disassemble this plate, bring the mount of the drill in the desired position and then reassemble the plate after engaging it on the drilling rod. This operation is not only a waste of time, but in addition, given the location, exposes the worker who executes it, at the risk of serious accidents.

The same problem exists for machines which bring the carriage into the operative position by a trajectory composed of a final approach movement and a final descent movement. Even for machines whose mounting trajectory does not, in the final phase, have a component perpendicular to the axis of the drill rod, this problem exists, because in these machines, the mounting generally pivots around a vertical or slightly inclined axis so that the end of the mount tangentially approaches the axis of the piercing rod in the final phase of the movement, or returns to this axis after having previously cut it.

One of the only machines capable of moving the front end of the carriage substantially in the axis of the tap hole during the final approach phase is proposed by patent application FR-A-2 427 568. For this machine, the problems discussed above have been solved thanks to the aforementioned Luxembourg patent which proposes a guide and support head fixed to the front of the carriage to be threaded on the drilling rod and to ensure alignment between that -ci and the gripping device. According to this patent, this guide head has a funnel-shaped opening for gripping the end of the piercing rod and compensating for the slight offset that may still exist, either as a result of the trajectory of the mount, or as a result of '' incorrect orientation of the drill rod. However, the subject of this patent did not solve the problems for other machines.

Furthermore, devices are known for guiding and centering the foil in a drilling machine by means of pivoting jaws as for example described in documents US-A-2789 789 and FR-A-1 264 949. However, these documents relate to machines in which, unlike the machines forming the subject of the present invention, the carriage does not undergo a gyratory movement before and after its operation so that the problems discussed above do not arise. In addition, the pivoting jaws are not used to thread the carriage into the foil, but to stabilize and guide the latter, in particular the crown of the foil to target the place to be drilled.

The aim of the present invention is to solve the problems discussed above for all types of tap hole drilling machines by means of a simple and effective centering and guiding device designed to be fixed on the front part of the lookout for these drilling machines.

To achieve this objective, the device proposed by the invention is essentially characterized in that the jaws are carried by parallel axes of rotation mounted at the front end of the mount perpendicularly to the longitudinal axis thereof and symmetrically on either side of the extension of the axis of the gripping device and in that the inner side of each of the jaws is designed in the form of an inclined ramp, the ramp of one of the jaws being in the upper part of the latter being oriented to act from top to bottom on the piercing rod, while the ramp of the other jaw is symmetrically in the lower half thereof and is oriented to act from bottom to top on the drilling rod.

The width of the jaws on the side provided with the inclined ramp is greater than half the spacing of their axes of rotation, so that these jaws partially overlap in the closed position.

According to a first embodiment, the jaws are designed to rotate in opposite directions. To prevent the jaws from colliding in this embodiment, at least one of the jaws is bent or curved.

According to a second embodiment, the two jaws are designed to rotate in the same direction and are oriented in opposite directions in the open position. In this case, the jaws may be flat.

The invention also relates to a machine for drilling a tap hole of a shaft furnace comprising a centering and guiding device of the kind described above.

• la figure 1 montre schématiquement une vue latérale d'un type particulier de machine de perçage lors de la phase d'approche de l'affût vers la position opérative ;
• la figure 2 montre une vue de la même machine en position opérative lors de l'opération d'extraction de la tige de perçage ;
• la figure 3 montre une vue schématique en plan d'un premier mode de réalisation en position ouverte ;
• la figure 4 montre une section suivant le plan de coupe IV-IV sur la figure 3 ;
• les figures 5 et 6 montrent des vues correspondant respectivement à celles des figures 3 et 4 lorsque les mâchoires se trouvent dans une position intermédiaire ;
• les figures 7 et 8 montrent des vues correspondantes lorsque les mâchoires sont en position complètement fermée ;
• la figure 9 montre schématiquement une vue en plan d'un deuxième mode de réalisation lorsque les mâchoires se trouvent en position ouverte ;
• la figure 10 montre une vue d'une section suivant le plan de coupe X-X de la figure 9 et
• les figures 11 et 12 montrent des vues correspondant à celles des figures 9 et 10 lorsque les mâchoires se trouvent en position complètement fermée.

Other particularities and characteristics will emerge from the detailed description of two advantageous embodiments, presented below by way of illustration, with reference to the appended figures in which:

• Figure 1 schematically shows a side view of a particular type of drilling machine during the approach phase of the carriage to the operative position;
• Figure 2 shows a view of the same machine in the operative position during the extraction operation of the piercing rod;
• Figure 3 shows a schematic plan view of a first embodiment in the open position;
• Figure 4 shows a section along the section plane IV-IV in Figure 3;
• Figures 5 and 6 show views corresponding respectively to those of Figures 3 and 4 when the jaws are in an intermediate position;
• Figures 7 and 8 show corresponding views when the jaws are in the fully closed position;
• FIG. 9 schematically shows a plan view of a second embodiment when the jaws are in the open position;
• FIG. 10 shows a view of a section along the section plane XX of FIG. 9 and
• Figures 11 and 12 show views corresponding to those of Figures 9 and 10 when the jaws are in the fully closed position.

In Figures 1 and 2, the reference 20 designates the base of the wall of a blast furnace. The reference 22 represents the tap hole obstructed by a plugging mass 24, such as hardened clay, through which a drilling rod 26 has been introduced, before hardening. This drilling rod 26 is abandoned in the position shown in FIG. 1 until the next taphole opening operation, an operation which consists in removing this piercing rod 26 to release the opening of the taphole 22. To facilitate gripping of this rod 26, the latter is provided at its end with a circular groove 28 or other suitable means.

To extract the piercing rod 26, we use a working tool equipped with a percussion member which can strike in both directions. In the figures, the reference 30 shows the lookout for a taphole drilling machine with a working tool 32 sliding along the lookout 30 and equipped with such a percussion member. Since this working tool 32 is designed to travel along the carriage 30, it can be used to extract the piercing rod 26, provided that there is an appropriate gripping device shown diagrammatically by the reference 34.

To be able to grasp the circular groove 28 by the gripping member 34, the mount 30 must be brought into an operating position in which the gripping member 34 is located substantially in the axis of the piercing rod 26 so to be able to be engaged by sliding along the carriage 30.

The carriage 30 shown in FIGS. 1 and 2 is that of a type of machine in which the final phase of this approach movement towards the operative position comprises a descent component and an approach component towards the furnace. In Figure 1 there is shown the carriage 30 in a position preceding the operative position, that is to say that the carriage must still descend and approach the oven so that the axis of the gripping device 34 is aligned with the axis of the drill rod 2.6.

However, this downward movement no longer allows the penetration into the drilling rod of a support and guide plate fixed to the end. moth before the lookout if this plate is not designed as a device as proposed by the invention and described in detail below. This centering and guiding device proposed by the invention is represented diagrammatically by the reference 36 in FIGS. 1 and 2 must in fact ensure the alignment of the axis of the piercing rod 26 with that of the gripping device 34 and vice versa even, if the approach movement by the carriage 30 does not allow this exact alignment or if the piercing rod 26, in particular its end, no longer occupies the axial position of the tap hole, as shown diagrammatically by the bent axis 26 'of the drilling rod.

When the carriage 30 is in the operative position and the centering and guiding device 36 has been correctly engaged on the piercing rod 26, the working tool 32 can be advanced until the gripping device 34 grasps the piercing rod 26 by the circular groove 28. From this moment, the working tool 32 can be actuated to move back along the carriage 30 and extract the piercing rod 26 from the tap hole 22. During this extraction, in particular during the final phase when the piercing rod 26 no longer has support in the taphole 22 it is supported by the device 36, as shown in FIG. 2.

A first embodiment of a centering and guiding device 36 will be described with reference to FIGS. 4 to 8. This device essentially consists of two pivoting jaws 38 and 40 whose axes of rotation 42 and 44 are mounted on the front end of the mount perpendicularly to the longitudinal axis thereof and symmetrically on either side of the extension of the axis of the gripping device 34 not shown in FIGS. 4 to 8. The two axes of rotation 42 and 44 are connected respectively by sets of articulated levers 50, 52 to a rod 48 of a jack 46 or of an electromechanical motor fixed on the carriage 30. The sliding of this rod 48 under the action of the jack 46 consequently causes the axes 42 and 44 to rotate and the jaws 38 and 40 to pivot between an open position according to FIG. 3 and a closed position according to FIG. 7.

As shown in Figures 4, 6 and 8, the inner side of each of the jaws 38 and 40 is designed as an inclined ramp 38a 40a respectively. The inclined ramp of one of the jaws, for example, the ramp 38a of the jaw 38, extends from the central region towards the upper part in order to exert on the rod 26 a thrust from top to bottom when it meets this during closing. Similarly, the ramp 40a extends symmetrically with respect to the ramp 38a from the middle region of the jaw 40 towards the lower part so as to exert a force from the bottom up on the rod during its encounter when the jaws are closed. .

As a result of the symmetrical arrangement of these jaws 38 and 40 and the presence of the inclined ramps 38a, 40a, these jaws delimit, during their movement, a diamond-shaped opening section evolving by increasing or decreasing symmetrically around the central axis which, by the arrangement of the axes of rotation corresponds to the extension of the axis of the gripping device 34.

During the approach movement of the carriage, the jaws are in the open position according to FIGS. 3 and 4 as shown diagrammatically in FIG. 1. The hatched area in broken lines represented by 54 in FIG. 4 represents the section maximum swept by the jaws during their closing movement. This amounts to saying that, when approaching the carriage, it suffices for the piercing rod 26 to be inside this interception area 54 without it being necessary for it to be in the 'central axis as shown in Figure 4. Indeed, when the cylinder 46 is actuated to close the jaws 38 and 40, the area 54 is gradually reduced through an intermediate diamond shape 54' (Figure 6) for be reduced to the minimum surface 54 ", also in the shape of a diamond around the central axis (FIG. 8). The final position of the rod 26 will therefore necessarily be a central position relative to the jaws and vice versa, even if this position was not central at the start of the closure of the jaws according to FIGS. 3 and 4. These jaws 38 and 40 therefore ensure that the piercing rod 26 is, after their closure according to FIGS. 7 and 8, in alignment with the gripping device 34.

When the closure of the jaws 38 and 40 occurs in a plane passing through the axes of rotation 42 and 44 as shown in FIG. 7, at least one of the jaws must be curved or bent, like the jaw 38. Indeed, since the jaws gradually overlap with their ramps 38a and 40a during closing, they would collide with each other in an intermediate position, as for example in the position of Figure 5, if the two jaws were flat. It is however possible to avoid this problem by means other than that given to the jaw 38.

The second embodiment shown in FIGS. 9 to 12 differs from the embodiment described above essentially by the fact that the two jaws 58 and 60 are oriented in opposite directions in the open position shown in FIGS. 9 and 10. In this embodiment, the rod 48 of the jack 46 (FIG. 1) is connected to one of the axes of rotation, in this case the axis 62, by a set of articulated levers 68. The other axis 64 of the jaw 60 is actuated from the axis 62 via a linkage 66. While in the first embodiment the jaws turned in opposite directions, in this second embodiment the jaws 58 and 60 rotate in the same direction when the action of the jack 46.

For the rest, the shape of the jaws 58, 60, as well as their operation, are similar to those of the previous embodiment, that is to say that, when they are closed, passing from the position according to FIGS. 9 and 10 to that of FIGS. 11 and 12, the jaws 58 and 60 bring the piercing rod 26 to a central position if it was not initially. In this second embodiment, there is no danger that the jaws 58 and 60 collide during their movements and, therefore, they can both be flat.

Claims (10)

1. Guiding and centering device for a drill rod (26) of the taphole (22) of a shaft furnace designed to be mounted on the front end of the tool holding bar (30) of the taphole drilling machine which is equipped with a device (34) for gripping the end (28) of the drill rod (26), which can slide along the tool holding bar (30) of the machine, comprising a pair of pivoting jaws (38, 40), (58, 60) of complementary shapes, and a mechanism serving to pivot the two jaws (38, 40), (58, 60) synchronously between an open position and a closed position in which the jaws (38, 40) (58, 60) grasp the drill rod, characterized in that the jaws (38, 40), (58, 60) are mounted on parallel rotation shafts (42, 44) (62, 64) at the front end of the bar (30) perpendicularly to the longitudinal axis of the latter and symmetrically on either side of the prolongation of the axis of the gripping device (34) and in that the inner side of each of the jaws (38, 40) (58, 60) takes the form of an inclined ramp (38a, 40a), the ramp of one of the jaws (38) being situated in the upper part of the jaw and orientated to act form the top downwards on the drill rod (26), while the ramp (40a) of the other jaw (40) occupies a symmetrical position in the lower part of the jaw and is orientated to act from the bottom upwards on the drill rod (26).

2. Device in accordance with claim 1, characterized by the fact that the width of the jaws (38, 40) (58, 60) on the side provided with inclined ramps (38a, 40a) is greater than half the space between their rotation shafts (42, 44) (62, 64) so that these jaws (38, 40) (58, 60) partially overlap when in the closed position.

3. Device in accordance with either of claims 1 or 2, characterized by the fact that the mechanism designed to pivot the jaws (38, 40) (58, 60) consists of a hydraulic or pneumatic jack (46) mounted on the tool holding bar (30) or of an electromechanical motor.

4. Device in accordance with either of claims 1 to 3, characterized by the fact that the jaws (38, 40) are designed to turn in opposite directions.

5. Device in accordance with claim 4, characterized by the fact that the shafts (42, 44) are respectively connected by a set of articulated levers (50, 22) to the rod (48) of the jack (46).

6. Device in accordance with claim 4, characterized by the fact that at least one of the jaws (38) is bent or curved.

7. Device in accordance with either of claims 1 to 3, characterized by the fact that the two jaws (58, 60) are designed to turn in the same direction and are oriented in opposite directions in the open position.

8. Device in accordance with claim 7, characterized by the fact that the jaws (58, 60) are flat.

9. Device in accordance with claim 7, characterized by the fact that the jack (46) is connected by its piston rod (48) and a set of articulated levers (68) to one of the rotation shafts (62), this latter being connected by a connecting rod system (66) to the second rotation shaft (64).

10. Shaft furnace tap hole drilling machine suitable for a process in which the opening and the closing of the tap hole (22) comprise respectively the operation of extracting and the operation of replacing the drill rod (26), which is left in the tap hole (22) between two successive tap- pings.

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