Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B12/00—Accessories for drilling tools
  • E21B12/06—Mechanical cleaning devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
  • B08B1/10—Cleaning by methods involving the use of tools characterised by the type of cleaning tool
  • B08B1/16—Rigid blades, e.g. scrapers; Flexible blades, e.g. wipers
  • B08B1/165—Scrapers

Definitions

• the present invention relates to the field of cleaning a drilling machine auger, such a machine being generally used to make piles in a soil.
• an auger is a drilling tool formed of a helical blade which is generally wound around a tubular axial rod.
• the auger is screwed into the ground to the desired depth. Pressurized concrete is then injected by the axial rod under the auger, which has the effect of gradually moving the auger upwards.
• This operation thus has the advantage of simultaneously concreting the pile, avoid collapse of the walls of the borehole during the extraction of the auger, and reduce the pulling force necessary to extract the auger.
• the extraction of the auger is generally performed without rotation of the latter, and this to avoid creating faults in the pile to achieve. Some extractions, however, are accompanied by a rotation of the auger, for example in the manufacture of pin piles.
• the cuttings are raised between the turns of the auger where they remain very often glued, even after their exit outside the borehole.
• Drilling machines equipped with cleaning devices are known for evacuating the cuttings housed between the turns of the auger.
• some comprise a rotary doctor blade which is inserted between two adjacent turns of the auger, the doctor blade rotating around the auger during the ascent, without rotation, of the latter.
• the invention relates more specifically to such a drilling machine comprising:
• an auger having a longitudinal axis parallel to the longitudinal direction and comprising a helical blade
• a displacement device for moving the auger relative to the mast in translation along the longitudinal direction
• an auger cleaning device comprising a carriage mounted to the mast slidably in the longitudinal direction of the mast, the carriage having a body surrounding the auger and a squeegee rotatably mounted to the body about an axis of rotation parallel to the longitudinal direction, the doctor blade extending between a lower turn and an upper turn of the helical blade.
• scraper blade is mounted on a member rotating at the desired speed around the auger, said member being supported by a frame capable of sliding upwards. bottom and bottom up along the carrier mast to which the auger is suspended.
• This sliding of the frame takes place in the event of a lack of synchronism between the speed of rotation of the scraper blade and the vertical extraction speed of the auger.
• This lack of synchronism has the effect of moving in translation the scraper blade, and thus the frame, along the mast.
• upper and lower stops are provided to prevent the sliding frame from being driven by the auger to either of the upper and lower ends of the mast.
• the frame may come bang against the stops and damage.
• the scraper blade may also be broken if the extraction speed of the auger continues to increase (or decrease) while the frame is in abutment with the upper (or lower) stop.
• Another disadvantage of the prior art is that existing doctor blade cleaning devices need to be manually engaged between two turns prior to concreting, and then cleared from the auger before the next drilling. These human interventions at the foot of the auger are potentially dangerous.
• An object of the present invention is to overcome these disadvantages.
• the invention achieves its object by the fact that the drilling machine further comprises a measuring member for determining the movement of the carriage along the mast with respect to an initial position of said carriage, and the cleaning device further comprises a device speed regulator for regulating the speed of rotation of the doctor blade according to said movement of the carriage.
• the regulation of the speed of rotation of the doctor blade according to the invention depends on the displacement of the carriage, so that the regulation of the speed of the doctor blade can be carried out during the different phases of manufacture of the pile.
• the speed regulation of the doctor blade can be performed when:
• the regulation of the speed of rotation of the blade makes it possible to correct the vertical position of the carriage.
• This speed regulation is preferably carried out in real time so as to maintain the carriage in a predetermined vertical position, for example the initial position of the carriage, or at least in a zone defined between two predetermined vertical positions, for example a centered zone. on the initial position of the carriage, and whatever the phase of realization of the pile. Consequently, the invention makes it possible to prevent damage to the squeegee by controlling the vertical position of the carriage and also to prevent human intervention at the level of the potentially dangerous carriage by virtue of the fact that the squeegee can remain engaged. between turns for the duration of the operations.
• the carriage during operation of the cleaning device during a concreting phase, the carriage is in the initial position, and the auger is extracted from the ground at a predetermined initial vertical extraction speed and constant.
• the doctor blade Under normal operating conditions, the doctor blade has a rotational speed determined so that the doctor blade performs a complete revolution around the auger when the latter has advanced one step of the helical blade. In these conditions, the truck does not move.
• the extraction speed of the auger is not necessarily constant.
• the movement of the carriage towards the lower end is determined by the measuring member and the speed of rotation of the doctor blade is regulated as a function of this movement of the carriage.
• the speed of rotation of the doctor blade is decreased, for example so as to stop or at least slow down the vertical movement of the carriage towards the lower end of the mast.
• the displacement of the carriage is determined by the measuring member and the speed of rotation of the doctor blade is regulated as a function of the movement of the carriage.
• the speed of rotation of the doctor blade is increased, for example so as to stop or slow down the vertical movement of the carriage towards the upper end of the mast. Thanks to this speed regulation, it prevents the carriage from reaching the upper end of the mast or a possible upper stop, which could cause damage to the doctor blade.
• determining the movement of the carriage relative to its initial position is meant that the measuring member is configured to measure the displacement of the carriage from its initial position, or at least to detect a movement of the carriage towards the upper end or the lower end of the mast.
• the speed control device is configured to change the speed of rotation of the doctor blade according to the movement of the carriage relative to the initial position, so as to bring the carriage back to the initial position when a displacement of the carriage relative to the initial position.
• the speed control device is configured to modify the speed of rotation of the doctor blade as a function of the displacement of the carriage relative to the initial position, so as to bring the carriage back to a zone situated around the initial position during a movement of the carriage out of said area.
• the speed control device thus makes it possible to maintain the carriage substantially in its initial position, whatever the variations, positive or negative, of the vertical extraction speed of the auger. This ensures that the carriage remains always away from any lower and upper stops.
• the speed regulating device is configured to increase the speed of rotation of the doctor blade when the carriage moves to an upper end of the mast. It is understood that, depending on its amplitude, the increase in the rotational speed of the doctor blade has the effect of slowing down or stopping the movement of the carriage towards the upper end, or even driving the carriage towards the lower end of the mast if the rotational speed of the doctor blade is greater than the ratio of the extraction speed on the pitch of the helical blade.
• This increase in rotational speed of the doctor blade is preferably initiated when the displacement of the carriage, as determined by the measuring member, is greater than a first predetermined threshold.
• the speed control device is configured to decrease the speed of rotation of the doctor blade when the carriage moves towards a lower end of the mast. It is understood that, according to its amplitude, the decrease in the rotational speed of the doctor blade has the effect of slowing or stopping the movement of the carriage towards the lower end of the mast, or even to move the carriage towards the upper end of the mast if the speed of rotation of the doctor blade is lower than the ratio of the extraction speed on the pitch of the helical blade.
• This reduction in rotational speed of the doctor blade can be initiated when the displacement of the carriage, as determined by the measuring element, is greater than a second predetermined threshold.
• the speed regulating device is configured so that the value of the speed of rotation of the doctor blade is a function of the value of the movement of the carriage determined by the measuring member.
• the speed of rotation of the doctor blade is an increasing function of the displacement value of the carriage, considered from the initial position towards the upper end of the mast.
• the speed of rotation of the squeegee increases more and more as the carriage approaches the upper end of the mast.
• the speed of rotation of the doctor blade decreases more and more as the carriage approaches the lower end of the mast.
• the speed regulating device is configured such that the speed of rotation of the doctor blade is a linear increasing function of the movement of the carriage along the mast.
• said measuring member is disposed between the carriage and the mast.
• the measuring member comprises at least one jack disposed between the body and the mast, the displacement of the carriage being determined from the variation in length of the jack.
• the measuring member comprises a displacement sensor integrated in the jack.
• the jack is a hydraulic cylinder.
• the high and low stroke end of the cylinder constitute lower and upper stops for the carriage.
• the weight of the auger cleaning device is increasing with increasing auger diameters, the squeegee, which generally bears on the lower turn, undergoes significant efforts that could seriously damage it.
• the cleaning device further comprises a force regulating device for regulating the force applied by the doctor blade on the lower turn.
• the force regulating device is configured to exert on the carriage a lift force counteracting at least part of the weight of the carriage, so as to reduce the force exerted by the doctor blade on the lower coil while ensuring that the scraper remains in support against the lower turn.
• the modulus of the lift force is equal to a fraction of the weight of the carriage.
• the force regulation device is disposed between the carriage and the mast.
• the force regulation device comprises at least one actuator disposed between the body and the mast, the actuator being configured to exert a thrust force on the body, said thrust force being directed in the longitudinal direction of the mast, towards an upper end of the mast.
• the actuator comprises a hydraulic cylinder.
• the hydraulic cylinder is fed at a constant hydraulic fluid pressure.
• the measuring member comprises the hydraulic jack of the actuator.
• the hydraulic cylinder disposed between the mast and the carriage has an advantageous dual function, namely to determine the movement of the carriage and reduce the force exerted by the doctor blade on the lower turn of the helical blade of the auger.
• FIG. 1 is a perspective view of a drilling machine according to the invention, the carriage of the cleaning device being in the initial position;
• FIG. 1 illustrates the drilling machine of Figure 1, the carriage being in the high position
• FIG. 3 illustrates the drilling machine of Figure 1, the carriage being in the low position
• FIG. 4 illustrates the drilling machine of FIG. 1 as well as its device for regulating the speed of the doctor blade
• FIG. 5 is a graph illustrating the variation of the doctor blade rotation speed as a function of the movement of the carriage along the mast.
• the drilling machine 10 is intended for drilling, and in particular piles in the ground. As this type of auger drilling machine is already known, only the elements necessary for understanding the invention will be described here.
• the drilling machine 10 comprises a mast 12 which has a longitudinal direction L; in this example, the longitudinal direction L is vertical.
• the drilling machine 10 further comprises an auger 14 having a longitudinal axis A parallel to the longitudinal direction L.
• the auger 14 comprises a hollow tube 16 which extends along the longitudinal axis A, this tube being fixed to and surrounded by a helical blade 18.
• the auger may be composed of several portions fixed end to end.
• the helical blade has an outer diameter D.
• the drilling machine 10 also comprises a displacement device (not shown here) to move the auger 14 relative to the mast 12 in translation along the longitudinal direction L.
• This displacement device is notably actuated during the drilling step and to screw the auger into the ground, and during the extraction step of the auger out of the ground.
• the extraction of the auger from the ground which occurs after the drilling operation, consists of a vertical translation without rotation.
• the drilling machine 10 further comprises a device 20 for cleaning the auger 14 whose function is to evacuate the cuttings housed between the turns of the auger. the helical blade during extraction of the auger.
• the cleaning device 20 comprises a carriage 22 which has the general shape of a drum traversed axially by the auger 14.
• the carriage 22 thus has a diameter slightly larger than the diameter D of the helical blade 18.
• the carriage 22 is slidably mounted to the mast 12 in the longitudinal direction L of the mast 12. To this end, in this nonlimiting example, the carriage is mounted on rails fixed along the mast.
• the carriage comprises a body 24 of cylindrical shape which surrounds the auger.
• the body 24 is supported by a pair of hydraulic cylinders 30 disposed between the mast and the carriage.
• the cleaning device 20 further comprises a doctor blade 40 which is disposed below the body 24.
• the doctor blade is mounted on an inner drum 26 of the cleaning device 20, the inner drum 26 being arranged coaxially inside the body 24.
• the doctor blade extends between a lower turn 18a and an upper turn 18b of the helical blade 18 in order to evacuate the cuttings lying between the two turns.
• the doctor blade remains engaged between the two turns during the other movements of the auger, especially during the drilling phases.
• the doctor blade has the shape of a plate having a height H substantially equal to the axial distance between the lower turn 18a and the upper turn 18b.
• the cleaning device 20 further comprises a motor 28 for rotating the inner drum 26 with the doctor blade 24 about the longitudinal axis A.
• the doctor blade rotates about the axis of rotation A of the auger while extending between the lower turn 18a and the upper turn 18b, which makes it possible to evacuate the cuttings housed between the lower turn and the upper turn. .
• the squeegee 40 is preferably mounted on the drum 26 pivotally so as to release the squeegee outside the volume of the auger when screwing the auger in the soil during the drilling operation.
• FIG. 1 there is shown a vertical axis Z which extends parallel to the longitudinal direction L of the mast and which is oriented towards an upper end 12a of the mast.
• the reference Z 0 corresponds to the initial position of the carriage 22 illustrated in FIG.
• the auger is in extraction phase without rotation, so that the vertical displacement speed of the auger corresponds to the vertical extraction speed.
• the initial speed ⁇ 0 of the doctor blade 40 about the axis of rotation A is set to be equal to Vo / p where p is the pitch of the helical blade 18, so that the carriage does not move. not vertically when the speed of extraction without rotation of the auger is equal to V 0 .
• the carriage 22 will be driven by the auger in the longitudinal direction L, or towards the upper end 12a of the auger.
• mast 12 if the extraction speed of the auger Vi is greater than the initial speed V 0 / as illustrated in FIG. 2, or towards the lower end 12b of the mast 12 if the vertical extraction speed V2 the auger is less than the speed V 0 , as illustrated in FIG.
• the measuring member 50 is disposed between the carriage 22 and the mast 12. It comprises the hydraulic jack 30, so that the displacement of the carriage 22 is determined from the variation of the length of the cylinder 30.
• the jack 30 comprises a displacement sensor 52 which makes it possible to measure the value of the displacement of the carriage 22.
• the non-rotating extraction speed V 2 is less than V 0 and the carriage 22 has moved towards the lower end 12a of the mast 12 by a distance ⁇ 2 to reach the Z 2 position. below the Z 0 position.
• ⁇ 2 ⁇ 2 - ⁇ , with ⁇ 2 ⁇ 0.
• the cleaning device 20 further comprises a speed control device 54, shown diagrammatically in FIG. 4 for regulating the speed of rotation ⁇ of the doctor blade 40 as a function of the displacement ⁇ of the carriage determined by the measured.
• the speed control device 54 is connected to the displacement sensor 52, and controls the motor 28 by providing it with a speed reference ⁇ of the doctor blade.
• the speed control device controls the speed control device
• the speed control device 54 is configured to change the speed of rotation ⁇ of the blade 40 as a function of the displacement ⁇ of the carriage, so as to bring the carriage 22 to the initial position Z 0 during a movement of the carriage relative to the initial position Z 0 .
• the speed control device 54 is configured to increase the speed of rotation ⁇ of the doctor blade 40 when the carriage 22 moves towards the upper end 12a of the mast 12.
• the measuring member 50 has determined that the carriage 22 has moved from the distance ⁇ towards the upper end 12a of the mast 12. Consequently, the speed regulating device 54 sends the speed instruction ⁇ to the motor 28 in order to increase the speed of rotation of the doctor blade 40.
• the rotational speed ⁇ is strictly greater than the initial speed ⁇ 0 . It will be explained below how the speed ⁇ is determined.
• the speed control device 54 is configured to reduce the speed of rotation ⁇ of the doctor blade 40 when the carriage moves towards the lower end 12b of the mast 12.
• the measuring member 50 has determined that the carriage 22 has moved by a distance ⁇ 2 from the initial position Z 0 to the lower end 12b of the mast 12. Consequently, the speed control device 54 decreases the rotational speed ⁇ of the doctor blade 40 to bring it to the speed of rotation ⁇ 2 lower than the initial speed ⁇ 0 .
• the speed control device 54 is configured such that the rotational speed ⁇ is a linear increasing function of the displacement ⁇ of the carriage along the mast.
• the rotational speed variation ⁇ of the doctor blade 40 is illustrated as a function of the Z position of the carriage 22 with respect to its initial position Z 0 .
• the curve illustrated in FIG. 5 is an increasing linear function representing the variation of speed as a function of the vertical displacement of the carriage with respect to Z 0 .
• ⁇ k * (Z-Zo), where k is the coefficient of proportionality.
• the pitch p of the blade is generally between 0.3 and 2 meters, and the speed of ascent of the auger can vary between 50 and 200 meters per hour.
• values of k make it possible to ensure that the speed of rotation of the doctor blade is adapted to stop the removal of the carriage 22 from its initial position Z 0 .
• Other values of k may be chosen according to the pitch of the blade.
• the device can also be parameterized so that the speed ⁇ is sufficient to return the carriage 22 to the initial position Z 0 , this displacement being illustrated by the arrow F1 in FIG. 2.
• the rotation speed variation ⁇ will be determined by choosing a coefficient k higher than those proposed above. It is understood in particular that the carriage will return to its initial position if the extraction speed without rotation fluctuates around the value V 0 .
• the rotational speed variation ⁇ 2 may be calibrated so that the carriage 22 returns to its initial position Zo when the carriage 22 is moved towards the lower end 12b of the mast 12, this displacement of the carriage being illustrated by the arrow F2 in FIG.
• the doctor blade 40 bears on the lower turn 18a of the helical blade 18.
• the force exerted by the doctor blade 40 on the lower turn 18a is constituted by the self weight of the carriage.
• the cleaning device further comprises a force control device 60, shown schematically in FIG. 1 for regulating the force applied by the doctor blade 40 on the lower turn 18a.
• This force regulation device 60 comprises the hydraulic cylinder 30 disposed between the carriage 22 and the mast 12.
• the jack 30 thus constitutes an actuator 31 which is arranged between the body and the mast being configured to exert a thrust force T on the body 24.
• This thrust force being, in this example, equal to a fraction of the weight of the carriage, in this case 50% of the weight of the carriage 22.
• the thrust force T is directed along the longitudinal direction L of the mast towards the upper end of the mast 12.
• this thrust force T reduces the vertical pressure force exerted by the doctor blade 40 on the lower turn 18a.
• the hydraulic cylinder 30 is fed at a constant hydraulic fluid pressure.
• the measuring member 50 comprises the hydraulic jack 30 of the actuator 31.
• the speed control device 54 is also able to regulate the speed of rotation of the doctor blade 40 during a vertical extraction phase of the auger 14 with rotation, which whatever its direction of rotation.
• the speed control device of the blade 40 is also able to regulate the speed of the doctor blade during the drilling phase, that is to say during a vertical downward movement of the auger with rotation, corresponding to a screwing movement of the auger into the ground.
• the regulating device is also able to regulate the speed of rotation of the doctor blade 40 during a rotation of the auger, without vertical displacement of the latter, in order to correct a displacement of the carriage 22 which could result from a variation of the rotational speed of the auger 14.

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• Engineering & Computer Science (AREA)
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• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Earth Drilling (AREA)

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• 2016
  • 2016-12-12 FR FR1662315A patent/FR3060048B1/fr active Active
• 2017
  • 2017-12-12 WO PCT/FR2017/053511 patent/WO2018109356A1/fr not_active Ceased
  • 2017-12-12 ES ES17822403T patent/ES2841336T3/es active Active
  • 2017-12-12 EP EP17822403.6A patent/EP3551829B1/de active Active

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