Drilling machine

A drilling machine (10) for making an excavation in ground in a drilling direction that is substantially vertical, the drilling machine including: an anchor module (22) having at least one anchor element for preventing the anchor module from moving relative to the walls of the excavation in the drilling direction, the anchor module having a longitudinal direction that is substantially vertical; a drilling module (12) provided with cutter members, the drilling module being movable in translation relative to the anchor module in the drilling direction; and a movement device (50) arranged between the anchor module and the drilling module in order to move the drilling module in translation relative to the anchor module in the drilling direction. The machine is suspended from a lift cable (70) that is fastened to the drilling module (12).

BACKGROUND OF THE INVENTION

The present invention relates to the field of drilling in the ground, in particular for the purpose of constructing foundations, such as for example continuous screens made up of juxtaposed concrete wall elements.

The invention relates more precisely to a drilling machine for excavating in the ground in a drilling direction that is substantially vertical, and more particularly in hard soil.

The invention relates more particularly to a machine comprising:

an anchor module having at least one anchor element for preventing the anchor module from moving relative to the walls of the excavation in the drilling direction, the anchor module having a substantially vertical longitudinal direction;

a drilling module provided with cutter members, the drilling module being movable relative to the anchor module in the drilling direction; and

a movement device arranged between the anchor module and the drilling module in order to move the drilling module relative to the anchor module in the drilling direction.

This type of drilling machine is generally used for drilling in hard ground, e.g. in granite. The movement device serves to exert additional thrust on the drilling tools, for the purpose of facilitating excavation.

Such a machine is described in particular in EP 0 811 724. It can be understood that the anchor module serves to hold the drilling machine stationary in the excavation.

In that machine, the movement device, constituted by jacks, supports the weight of the drilling module while the machine is suspended, i.e. while it is not in contact with the ground for drilling. This applies in particular while the drilling machine is being moved, e.g. in order to be taken to the zone for drilling, or indeed while it is being extracted from the excavation after the drilling operation.

The drilling module is particularly heavy when it has motor-driven cutter members, hydraulic circuits, and the pump member. It can thus be understood that the jacks need to support a weight that is very large when the drilling machine is suspended, which might damage them.

OBJECT AND SUMMARY OF THE INVENTION

An object of the present invention is to remedy the above-mentioned drawbacks by proposing a drilling machine that is more robust.

The invention achieves this object by the fact that the drilling machine of the invention is suspended from a lift cable that is fastened to a fastener portion of the drilling module.

In other words, in the invention, it is the drilling machine that is suspended from the lift cable, and not the anchor module as with the prior art drilling machine.

Insofar as the drilling module is generally heavier than the anchor module, it can be understood that the movement device supports only the weight of the anchor module while the drilling machine is suspended. The movement device is then stressed to a smaller extent, thus enabling its lifetime to be increased.

Another advantage of the invention is that in the event of the anchor module becoming jammed, the drilling module remains supported by the lift cable.

It can thus be understood that the lift cable is connected directly to the drilling machine, and indirectly to the anchor module via the drilling module and the movement device.

The drilling machine presents a deployed position in which the cutter members are remote from the anchor module, and a retracted position in which the cutter members are closer to the anchor module.

The term “substantially vertical” is used to mean a direction that makes an angle of absolute value that is less than or equal to 10° relative to the vertical.

Advantageously, the fastener portion extends above the anchor module.

By means of this configuration, the anchor module remains below the lift cable, thus making it possible to avoid damaging said cable.

In a preferred first embodiment, the drilling module presents a bottom section carrying the cutter members, and a top section extending in the longitudinal direction of the anchor module inside said anchor module, the fastener portion being arranged at the top end of the top section of the drilling module.

It can be understood that the top section projects beyond the top end of the anchor module.

In addition, the anchor module includes means for guiding the top section of the drilling module in translation along the longitudinal direction of the anchor module.

Preferably, the top section is a bar mounted to slide in the anchor module, said bar passing longitudinally through the anchor module. Preferably, but not exclusively, the bar extends above the top end of the anchor module.

In a preferred variant, the anchor module has two anchor elements arranged on either side of the bar, the anchor elements being connected to each other and extending in the longitudinal direction of the anchor module.

This advantageous configuration serves to reduce the weight of the anchor module. The two anchor elements are connected to each other by guide members in which the top section of the drilling module, in particular the bar, slides.

In a second embodiment, the drilling module presents a bottom section carrying the cutter members, and a top section surrounding the anchor module, the fastener portion being arranged at the top end of the top section of the drilling module.

It can thus be understood that the anchor module is arranged in the top section of the drilling module.

An advantage of this shape is that the drilling module then presents two wide opposite anchor faces, which can be preferable for ensuring grip in certain types of soil. Another advantage is to reduce the number of actuators needed for deploying the anchor elements.

In an advantageous aspect of the invention, the drilling module is mounted to pivot relative to the anchor module in a first vertical plane, and at least one of the bottom section and the top section includes path correction means for causing the drilling module to pivot relative to the anchor module in said first vertical plane.

To do this, the drilling module is preferably mounted relative to the anchor module with clearance suitable for accommodating such pivoting in the first vertical plane.

The path correction means thus enable the position of the drilling module relative to the anchor module to be modified in three dimensions in order to modify the position of the cutter members, thereby enabling the drilling path to be adjusted.

Such path adjustment by pivoting the drilling module is preferably performed after ensuring the anchor module is stationary in the excavation.

Preferably, the path correction means comprise deployable pads arranged on the front and rear faces of the bottom and/or top sections in order to bear against at least one of the walls of the excavation in order to cause the drilling module to pivot relative to the anchor module.

The front and rear faces of the bottom section and of the top section are those arranged facing the larger walls of the excavation.

It can be understood that when one of the deployable pads comes to bear against one of the walls of the excavation, it gives rise by reaction to the drilling module pivoting relative to the anchor module, and thus relative to the excavation.

Advantageously, the bottom section further comprises an anti-swinging device.

An advantage is to prevent the drilling module from swaying, thus making it possible to avoid the drilling path deviating from the desired path.

For this purpose, the anti-swinging device preferably comprises deployable pads configured to bear against at least one of the walls of the excavation in order to prevent the drilling module from pivoting in a second vertical plane that is orthogonal to the first vertical plane. The deployable pads are preferably arranged on the lateral sides of the bottom section of the drilling module.

Advantageously, the movement device comprises one or more thrust actuators arranged between the anchor module and the drilling module.

Preferably, the movement device is arranged between the anchor module and the bottom section of the drilling module.

Advantageously, the movement device includes damper means for damping the vibration generated by the cutter members of the drilling module when drilling.

Preferably, but not exclusively, damping is performed hydraulically by means of a hydraulic damper device. Preferably, but not exclusively, the damper device comprises a spring accumulator with at least one nozzle. In the event of an impact, the oil contained in one of the chambers of the hydraulic thrust actuator is compressed and flows through the nozzle towards the spring accumulator in order to damp the pressure rise of the oil, thus performing damping. Preferably, the leakage flow rate through the nozzle and the prestress of the spring accumulator are adjustable, thereby making it possible to adjust the damping coefficient and the resistance to reversing of the actuators as a function of the weight applied on the cutter members.

Alternatively, the damper means comprise one or more springs associated with the thrust actuators.

Advantageously, the anchor element includes at least one front anchor pad and at least one rear anchor pad, the front and rear anchor pads being deployable in a transverse direction that is transverse relative to the longitudinal direction of the anchor module, so as to bear against the walls of the excavation in order to prevent the anchor module from moving in the ground.

Preferably, the anchor pads are deployed by actuators, such as hydraulic actuators, arranged in the anchor module.

Advantageously, the drilling machine is a milling machine in which the cutter members comprise two pairs of drums that are rotatable about axes of rotation that are parallel, distinct, and perpendicular to the drilling direction.

It is specified that the above-mentioned first vertical plane is then parallel to the axes of rotation, while the second vertical plane is orthogonal to the axes of rotation.

In order to discharge the excavated soil, the drilling module further includes a spoil suction device comprising a pump member arranged in the bottom portion of the drilling module and a discharge pipe connected to the pump member and extending inside the drilling module to a top end of the drilling module situated above the anchor module.

Having the drilling module suspended from the lift cable has the advantageous effect of making it easier to integrate hoses in the drilling machine, and in particular the spoil discharge pipe.

When the drilling module has a top section in the form of a bar, the discharge pipe extends inside said bar.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 1, 2A, and 2B, the description begins with a first embodiment of a drilling machine10in accordance with the present invention. The drilling machine10is designed to make an excavation E in ground S along a drilling direction F that is substantially vertical. In other words, the drilling machine10of the invention is designed to make vertical trenches in the ground. The drilling machine10has a drilling module12that is provided with cutter members14that, in this example, comprise two pairs of drums16,18that rotate about axes of rotation A, B that are parallel, distinct, and perpendicular to the drilling direction F. The pairs of drums16and18carry cutter teeth referenced20. In this example, it can be understood that the drilling machine10is a milling machine.

The drilling machine10also has an anchor module22located above the cutter members14and that presents a longitudinal direction L that is substantially vertical. The anchor module22has anchor elements24that serve to prevent movement of the anchor module22relative to the walls of the excavation E in the drilling direction F. In other words, when they are actuated, the anchor elements hold the anchor module stationary in the ground. In the first embodiment, the anchor module22has two anchor elements24, each anchor element comprising four front anchor pads30and four rear anchor pads32. It can be understood that the front anchor pads30are arranged on the front face26of the anchor module22, while the rear anchor pads32are arranged on the rear face28of the anchor module22.

The front and rear anchor pads30,32can be deployed in a transverse direction T that extends transversely relative to the longitudinal direction L of the anchor module, so as to bear against the two opposite larger walls P1, P2of the excavation E, thereby preventing the anchor module22from moving in the ground S. For this purpose, the anchor pads are deployed by actuators arranged in the anchor module.

With reference once more toFIG. 2A, it can be seen that the drilling module12presents a bottom section40that is arranged under the anchor module22and that carries the cutter members14together with a pump member42and a spoil suction device44. The pump member42has a nozzle46that opens out between the two pairs of drums16,18in order to suck in fragments of excavated ground.

The drilling module12also has a top section51that is in the form of a longitudinal bar extending vertically, and that extends from a top end40aof the bottom section40.

As can be seen inFIGS. 1, 2A, and 2B, the top section51in the form of a bar extends along the longitudinal direction L of the anchor module inside said anchor module22. More precisely, the top section51in the form of a bar passes longitudinally through the anchor module22, and projects above the top end22aof the anchor module22.

It can also be seen that the two anchor elements24are arranged on opposite sides of the bar-shaped top section51.

Furthermore, the drilling module12is movable in translation relative to the anchor module along the drilling direction F, i.e. in a direction that is substantially vertical. The drilling module can thus go from a retracted position, as shown inFIG. 2A, in which the cutter members14are close to the anchor module22, to a deployed position, shown inFIG. 2B, in which the cutter members14are further away from the anchor module.

For this purpose, the drilling machine10has a movement device50, specifically hydraulic thrust actuators52,54that are arranged between the anchor module22and the drilling module12in order to move the drilling module in translation relative to the anchor module in the drilling direction. More precisely, the movement device50, constituted by the thrust actuators52and54, is arranged between the bottom end22bof the anchor module and the top end40aof the bottom section40of the drilling module12.

It can thus be understood that the effect of actuating the thrust actuators52,54is to move the drilling module12relative to the anchor module22in translation along the drilling direction F. In particular, when the anchor module is stationary in the ground, the effect of actuating the thrust actuators is to exert thrust on the cutter members14that is directed in the drilling direction F.

The spoil suction device44also has a discharge pipe45that is connected to the pump member42and that extends inside the drilling module, and more precisely inside the bar-shaped top section51as far as the top end of the drilling module12that is situated above the anchor module22. This discharge pipe45serves to discharge the excavated spoil towards a spoil treatment station situated on the surface.

In the example ofFIG. 2A, the movement device50also has damper means60for damping the vibration generated by the cutter members14of the drilling module while drilling.

The damper means60are shown inFIG. 8. They comprise a hydraulic damper device62that is in fluid flow connection with the hydraulic thrust actuators52,54. In this example, the hydraulic damper device preferably includes a spring accumulator64with at least one nozzle. When the cutter members14are subjected to an impact, oil contained in one of the chambers52a,54aof the hydraulic thrust actuators52,54is compressed and flows through the nozzle to the spring accumulator64in order to damp the pressure rise in the oil, thereby performing damping. The damper means60also include a device66for regulating the damping coefficient of the damper means, and more precisely the damping coefficient of the spring accumulator64. Thus, during an impact, the vibration generated by the cutter members is not transmitted to the anchor module22.

The leakage flow rate through the nozzle and the prestress of the spring in the accumulator are preferably remotely adjustable.

In accordance with the invention, the drilling machine10is suspended from a lift cable70that is fastened to a fastener portion53of the drilling module12. In this example, the fastener portion53is arranged at the top end of the drilling module. In known manner, the lift cable70serves to suspend the drilling machine10from a hoist (not shown).

More precisely, in this first embodiment, the lift cable70is fastened to a top end51aof the top section51of the drilling module12. It can be seen that this top end51aof the top section51of the drilling module12forms the fastener portion53that extends above the anchor module22and to which the lift cable70is fastened.

As can be seen inFIG. 2A, the two anchor elements24are connected to each other by connection members25that also constitute means for providing guidance in translation to the bar-shaped top section51. The connection members24form sheaths in which the bar-shaped top section51is mounted to slide in the drilling direction.

When considered in the transverse direction T, parallel to the deployment direction of the anchor pads, clearance is left between the top section51and the connection members25so that the anchor module12can pivot relative to the anchor module22, with this pivoting taking place in a first vertical plane Q1that is parallel to the axes of rotation A and B of the drums. This first vertical plane Q1is shown inFIG. 1. It is specified that the pivoting of the drilling module12relative to the anchor module22is of the order of a few degrees and serves to modify the position of the cutter members14in order to correct the drilling path, should that be necessary.

FIGS. 6 and 7are diagrams showing the drilling machine of the invention in side view, and the description below explains how the drilling module12is pivoted relative to the anchor module22. The bottom section40of the drilling module12has path correction means80that serve to cause the drilling module to pivot relative to the anchor module in the first vertical plane Q1. For this purpose, these path correction means comprise deployable pads82,84that are arranged on the front face40aand on the rear face40bof the bottom section40of the drilling module.

The deployable pads82,84are configured to bear against one or the other of the larger walls P1, P2of the excavation E in order to cause the drilling module to pivot relative to the anchor module.

In the example ofFIG. 7, it is the deployable pad84of the rear face of the bottom section40of the drilling module that is actuated to bear against the wall P2. In reaction, the drilling module12pivots in the first vertical plane Q1so that the cutter members14move towards the opposite wall P1of the excavation. Insofar as clearance exists between the connection members25and the top section of the drilling module, it can be understood that the drilling module can be tilted a little relative to the anchor module, thus making it possible to adjust the positions of the cutter members14. Naturally, inFIG. 7, the pivot angle α is exaggerated in order to make the invention easier to understand.

It is also specified that the drilling module12can be pivoted relative to the anchor module22while the anchor module is held stationary in the ground S as a result of the anchor elements24being actuated so that the anchor pads30and32are deployed.

In another example utilization, the drilling module is caused to pivot initially in order to correct the drilling path, and then the anchor module is held stationary in the ground, after which the cutter members are actuated.

In order to avoid the drilling machine10swinging at the end of the lift cable70in a vertical plane Q2that is orthogonal to the first vertical plane Q1, the bottom section40also has an anti-swinging device86. As shown diagrammatically inFIG. 1, the anti-swinging device86comprises deployable lateral pads88that are configured to bear against one or other of the smaller walls P3, P4that are orthogonal to the larger walls P1, P2. It can be understood that actuating the deployable lateral pads serves to stabilize the drilling module so that it does not present any swinging movement in the second vertical plane Q2.

With reference toFIGS. 3 to 5, there follows a description of a second embodiment of the drilling machine110of the invention. Technical features shared in common with the first embodiment are given the same references plus100.

The drilling machine110comprises a drilling module112having cutter members114. The drilling machine110also comprises an anchor module122that extends in a substantially vertical longitudinal direction L and that is provided with two anchor elements124for preventing the anchor module122from moving relative to the walls of the excavation E in the drilling direction F, which is likewise substantially vertical.

The anchor elements comprise front anchor pads130and rear anchor pads (not shown) that are arranged on each of the larger front and rear faces of the anchor module. These anchor pads are deployable so as to bear against the larger walls P1, P2of the excavation in order to prevent the anchor module from moving in the ground S.

The drilling module112is also provided with cutter members114, the drilling module being movable in translation relative to the anchor module along the drilling direction F. In this second embodiment, the drilling module112presents a bottom section140that carries the cutter members114together with a top section151that extends above the bottom section140. In particular manner, in this second embodiment, the top section151presents a structure that surrounds the anchor module122.

FromFIGS. 4 and 5, it can be understood that the anchor module122is mounted to slide inside the top section151of the drilling module. The drilling module112is moved relative to the anchor module by a movement device150(visible inFIG. 5) that has a single thrust actuator152. This thrust actuator152is arranged between the anchor module122and the bottom section140of the drilling module112.FIG. 4shows the drilling machine in the retracted position, whileFIG. 5shows the drilling machine in the deployed position, the thrust actuator152itself being deployed such that the cutter members114are further away from the anchor module122.

The drilling machine110in the second embodiment of the invention is also suspended from a lift cable170that is fastened to a fastener portion153of the drilling module that is arranged at a top end112aof the drilling module112. The fastener portion153extends above the anchor module122, the lift cable170thus being fastened to said fastener portion153.

The drilling module112is also mounted with clearance relative to the anchor module122. Consequently, as in the first embodiment, the drilling module112of the drilling machine in the second embodiment is likewise pivotally mounted relative to the anchor module122. This pivoting takes place in a similar manner to that shown inFIG. 7.

In order to perform such pivoting, the bottom section140has first path correction means180that comprise front bottom deployable pads182on the front face140aand rear bottom deployable pads184on the rear face140b. In addition, the top section151has second path correction means190that comprise front top deployable pads192arranged on the front face151band rear top deployable pads194arranged on the rear face151cof the top section of the drilling module.

These deployable pads182,184,192,194are configured to bear against one or the other of the larger walls P1, P2of the excavation E so as to cause the drilling module to pivot relative to the anchor module in the first vertical plane Q1. It can be understood that the front bottom deployable pads182of the bottom section140of the drilling module are actuated together with the rear top deployable pads194arranged on the rear face of the top section151so as to facilitate pivoting the drilling module relative to the anchor module in a first direction. Conversely, the rear bottom deployable pads184of the bottom section140are actuated together with the front top deployable pads192of the front face of the top section151of the drilling module likewise so as to facilitate pivoting of the drilling relative to the anchor module in a second pivot direction, opposite to the first direction.

It can also be understood that the pivot axis of the drilling module is horizontal and is situated substantially between the deployable pads192,194of the top section and the deployable pads182,184of the bottom section.

The bottom section140of the drilling module also has an anti-swinging device186comprising deployable lateral pads188arranged along the lateral sides of the bottom section140, these deployable lateral pads being configured to bear against one or the other of the smaller walls P3, P4of the excavation. It is specified that the lateral sides140c,140dof the bottom section140are contiguous with the front and rear faces of said bottom section140.

The drilling machine110in the second embodiment has damper means similar to those of the first embodiment, as shown inFIG. 8.

Like the first embodiment, the drilling machine110in the second embodiment is likewise a milling machine having cutter members114that comprise two pairs of drums116,118provided with cutter teeth that rotate about axes of rotation A, B that are parallel, distinct, and perpendicular to the drilling direction F.

The drilling module112also has a spoil suction device144that comprises a pump member142arranged in the bottom portion of the drilling module and a discharge pipe145for discharging the spoil.

The discharge pipe145is connected to the pump member142, and it extends inside the drilling module and the anchor module to a top end of the drilling module that is situated above the anchor module, the discharge pipe145passing through the fastener portion153.