ES2664424T3 - Excavation tool for a TBM, and a TBM comprising such a tool - Google Patents

Abstract

Excavation tool (4) for a tunnel boring machine (1), comprising: - a tooth (20) to attack the ground to be excavated; - a support (10) for mounting the tooth, the support being provided to be permanently fixed to a cutting head (2) of the TBM, the support and the tooth being shaped to be engaged with each other so that they fixedly connect the tooth with the support in all spatial directions except in an uncoupling direction (D); and - a detachable fixing screw (30) of the tooth to the support, the screw being provided with a thread (34) that is screwed into a thread (26) of the tooth, the decoupling direction (D) being transverse to the central axis ( Y2) of this thread; in which, in an assembled configuration of the digging tool (4), the tooth (20) is mechanically engaged directly with the support (10) in the other directions other than the decoupling direction (D) and the screw (30) interferes with the support in the direction of decoupling (D) to block the tooth from the support; characterized in that the threading (26) of the tooth (20) and the filleting (34) of the screw (30) are designed to, by screwing-unscrewing, keep the tooth and the screw integral with one another while the digging tool ( 4) passes between the mounted configuration and a disassembled configuration in which the screw does not interfere with the support (10) in the decoupling direction (D) so that, by dragging only in the decoupling direction, the tooth and the screw they are decoupled from the support, while by dragging only in a direction opposite to the direction of decoupling, the tooth and the screw are mounted on the support.

Description

DESCRIPTION

Excavation tool for a TBM, and a TBM comprising such a tool

[0001] The present invention relates to an excavation tool for a TBM, as well as a

TBM comprising such an excavation tool.

[0002] A tunnel boring machine, also called a tunnel excavation machine, comprises a tubular housing on whose front part a shield is provided whose outer diameter corresponds to the diameter of the excavated tunnel.

10 The front part of the shield that is in contact with the excavation front to excavate the terrain crossed by the tunnel boring machine, involves a cutting head that creeps in rotation around itself around an axis that corresponds to the central longitudinal axis of the tunnel boring machine . The demolition of the land is obtained by the rotation of the cutting head and the simultaneous advance of this is generated by a strong push against the excavation front. At the rear of the front shield, the casing of the TBM is internally equipped with means for moving the TBM forward, a system for evacuating the debris that results from the demolition of the land and a device for placing slots. inside the excavated tunnel to progressively manufacture a tube that lines the inside of the tunnel.

[0003] The cutting head comprises radial arms that support excavation tools intended for the demolition of the land. A distinction is made between tools that spin freely on themselves

on a supportive shaft of the cutting head and which are typically cutting wheels that rotate on the excavation front to cut it, and the tools that, in service, are intended to be fixed on the cutting head and that attack the front of scratching excavation. The invention is interested in the latter type of excavation tools that, in a classical way, involve an attack tooth of the ground that must be excavated, sometimes called a beak, brush or knife. This tooth is subjected, due to the geological nature of the traversed terrain, to strong mechanical stresses and to abrasion, whether it is worn or even broken so it must be replaced periodically. In this optic, the tooth is mounted interchangeably on a specific support, permanently fixed, usually by welding, to the arms of the cutting head. In practice, the tooth is retained on the support by detachable fixing means, which must allow for a disassembly of the spent tooth 30 and a reassembly of a new tooth, both easy, using portable and usual tools, and quick to avoid too long immobilization of the tunnel boring machine. Of course, these fixing means must be adapted to the operating conditions of the excavation tool, in particular to the stresses and shocks suffered by the tool, as well as to the presence of debris and water. In addition, in principle, these fixing means must be provided to limit the limitations of use and minimize the weight of the 35 tools that must be handled by the operators who have to carry out the maintenance operations of the excavation tool, in particular the operation of replacement of your tooth: in fact, these operations are carried out in difficult conditions for operators, from a chamber, often in overpressure, between the cutting head and a fixed vertical partition arranged behind said head.

[0004] A first solution, the most widespread, is to fix the tooth to the support by means of several screws,

for example, four or more screws, which pass through a smooth bearing of the tooth to be screwed into complementary threads of the support, until the tooth is pressed against the support. This solution has drawbacks. Indeed, the accessibility to the screw heads is delicate when they must be associated with washers and ideally be tightened with a torque wrench, which implies long and repetitive manipulations for the operator, with the risk of the screws escaping or lose In addition, these screws directly support most of the efforts applied to the tooth. In addition, in the long run, support threads tend to be damaged due to stress and corrosion.

[0005] A second solution is to block the tooth on the support so that, in service, the

50 efforts applied to the tooth are essentially recovered by the support, providing that the tooth can be separated from the support in at least one predetermined decoupling direction. To prevent this decoupling when it is not desired, a screw goes through the tooth and the support at the same time and tightens them against each other by adding a fixing nut at the end of the screw, opposite its head. This solution also has drawbacks. Indeed, it is necessary, both in assembly and disassembly, to manipulate the screw and its associated nut at the same time: under the maintenance conditions mentioned above, and taking into account the various possible orientations of the tool related to the angular position of the cutting head, the screw is usually extended inclined with respect to the horizontal, it is understood that these manipulations require two operators, or there is a high risk of losing the screw and / or the nut.

[0006] In addition, both for one and the other of these solutions, the decoupling of the tooth from the support requires that the screws be completely separated from the tooth and the support, where appropriate, after being released from its nut: it is understood that the movements required in the corresponding operations are numerous and complex, which means that, in practice, these operations cannot, with a

5 reasonable cost, be made by manipulative robots.

[0007] A third solution has been proposed by document EP1 253 286-A1 on which the preamble of claim 1 attached is based. As in the case of the second solution mentioned above, when in service, the tooth is locked on the support in all spatial directions except in

10 a decoupling address. To prevent the tooth from disengaging from the support during the rotation of the cutting head, a screw fixes the tooth to the support in a detachable way: in a mounted configuration of this digging tool, the threaded end of the screw is screwed into a thread of the tooth, whose central axis is parallel or slightly inclined with respect to the disengagement direction, while the screw head rests on a wall of the support through which the screw extends. To disengage the tooth from the support while maintaining the integral screw of this tooth, the screw is partially unscrewed, and then it is necessary to move the tooth first according to a first movement of movement in the direction of disengagement, then according to a second movement of translation in a direction perpendicular to this direction of decoupling: the first movement allows only partially to disengage the tooth with respect to the support, since the continuation of this first movement is impossible because of the interference, in the direction of decoupling, of the head of the screw and the mentioned wall of the support. The displacement of the tooth according to the second movement is due to the fact that the screw shank crosses the mentioned wall of the support by means of a groove of this wall, said groove being oriented in the direction of the second translation movement and open at its end to leave leave the screw shank and thus allow effective disengagement of the tooth and the screw from the support. The successive application of the first and second mentioned movements can be delicate, in particular for a manipulator robot.

[0008] The object of the present invention is to propose an excavation tool of the type evoked above, in which the assembly and fixing of the tooth are efficient and rapid, as well as particularly simple to carry out, potentially automatically by a robot.

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[0009] For these purposes, the invention is directed to an excavation tool for a tunnel boring machine, as defined in claim 1.

[0010] Thanks to the invention, the fixing of the tooth on the support is carried out by at least one screw which, both when the tooth is mounted on the support and the tool is thus in a state of service, and when the

The tooth is disassembled with respect to the support and the tool is thus in a state of maintenance for the repair or change of the tooth, it is physically held in solidarity with the tooth, being screwed to this tooth. Thus there is no risk of losing or leaking the screw during tooth manipulations. The passage of the tool according to the invention between its assembled and disassembled configuration is carried out by relative screw-unscrewing 40 between the screw and the tooth. In addition, once the tool is in a disassembled configuration, the joint drag of the tooth and the screw exclusively in the direction of decoupling allows this tooth to be completely disengaged from the support; the assembly of the «tooth + screw» assembly on the support, on the other hand, is obtained entirely by dragging this assembly exclusively in the opposite direction to the decoupling direction. Thus, the movements initiated for the assembly and disassembly of the tool, that is to say, the screwing and unscrewing of the screw and the rectilinear drag of the "tooth + screw" assembly parallel to the coupling direction, are limited, constant and repetitive. , and the set «tooth + screw>» remains intact and integral: the assembly and disassembly operations are facilitated and shortened by a human operator, these operations being even easily adaptable to an automatic realization by a manipulator robot.

[0011] In addition, in the assembled tool configuration, the screw supports only few, or almost

no effort exerted by the ground on the tooth during the scraping action of the latter on the excavation front: indeed, thanks to the direct gear between the tooth and the support, specifically by blocking, these efforts are recovered mostly, even exclusively, by the support, except in the direction of decoupling of the tooth from the support, in which direction the screw guarantees the locking of the tooth 55 with respect to the support by interfering with the latter. In practice, the part of the efforts applied precisely in this direction of decoupling is weak, even marginal, with respect to the set of efforts that, accumulated, are exerted on the tooth, these efforts being oriented to a very high number of directions, according to the roughness of the excavation front and as the cutting head rotates. It is understood that the screw of the excavation tool according to the invention can, advantageously, be sized accordingly to the

minimum and planned in a single copy, which reinforces the ease of handling, guaranteeing the reliability of the excavation tool in service.

[0012] These additional advantageous features of the excavation tool according to the invention 5 are specified in claims 2 to 10.

[0013] Another object of the invention is a tunnel boring machine, comprising a cutting head, and at least one excavation tool, which is as defined above and whose support is permanently fixed to the cutting head.

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[0014] The invention will be better understood from reading the following description, given by way of example only and which refers to the accompanying drawings in which:

- Figure 1 is a front view of a TBM according to the invention;

15 - Figure 2 is a perspective view of an excavation tool according to the invention, in assembled configuration;

- Figure 3 is an exploded perspective view of the tool of Figure 2;

- Figure 4 is a perspective view, under an observation angle different from that of Figure 3, of the tool of Figure 2, in disassembled configuration;

20 - Figures 5 to 7 are sections according respectively to planes V, VI and VII of Figure 2; Y

- Figure 8 is a view similar to Figure 7, showing the tool in disassembled configuration.

[0015] In figure 1 a tunnel boring machine 1 is shown schematically whose tubular housing, with a substantially circular base, includes a front shield that comprises, in its front part, a cutting head 2 which is

25 in contact with the excavation front excavated by the TBM. In a manner known per se, the cutting head 2, sometimes called the drilling head, is designed to be rotated about it about a shaft 2A that corresponds substantially to the central longitudinal axis of the tubular casing of the tunnel boring machine 1. In figure 1, the tunnel boring machine 1 is seen from the front and on the axis 2A, so that only its cutting head 2 is visible, the rest of the tunnel boring machine extends backwards and in the axial extension of the head.

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[0016] As explained in the introduction of this document, the TBM 1 excavates a land demolishing the latter under the action of the rotation of the cutting head 2 and the simultaneous advance of this head, generated by a strong thrust against the digging front. In the exemplary embodiment considered in Figure 1, the cutting head 2 comprises arms 3 extending radially towards the axis 2A. These radial arms 3

35 delimit between them openings that lead, towards the rear of the head 2, into a demolition chamber from which the debris removed from the excavation front by the head 2 is evacuated. Each of the radial arms 3 carries tools of excavation 4 designed to demolish the ground by scratching, one of said tools 4 is represented alone and on a larger scale in figures 2 to 8. Of course, the cutting head 2 can be equipped with other excavation tools other than tools 4 : Thus, in the example of an embodiment considered in Figure 1, each of the radial arms 3 also carries cutting wheels 5, which freely rotate on themselves in a carriage shaft of the arm and which, in service, rotate on the digging front to cut it.

[0017] To facilitate the description of the excavation tool 4 that follows, this description is oriented with respect to a spatial reference consisting of three geometric axes X, Y, Z, drawn in Figures 2 to 4 and

orthogonal between them. For convenience, the Z axis is associated with the vertical, considering that its direction is directed upwards when it points towards the top of Figures 2 to 6, while it is directed downwards in the opposite direction. The X and Y axes define a horizontal geometric plane, the X axis being associated with an anteroposterior direction that is oriented towards the front when it points towards the right side of Figures 2 and 4 50 to 6, while it is oriented towards the part rear in the opposite direction.

[0018] As is clearly visible in Figure 3, the excavation tool 4 comprises, even is constituted, by three main components that are a support 10, a tooth 20 and a screw 30.

[0019] As is clearly visible in Figures 3 and 4, the support 10 includes a lower base 11 which, in its part

rear, it is crowned by two branches 12 and 13. Branches 12 and 13 are distant from each other in the direction of the Y axis. As is clearly visible in Figures 4 and 6, the back of the base 11 is lowered between branches 12 and 13, throughout the extent of the separation, along the Y axis, between those branches. The base 11 thus delimits an upper surface 11A, which is inscribed in a plane perpendicular to the Z axis and which, in the example considered in the figures, is

It extends, at the same time, between branches 12 and 13 and in the front of each of them. At the height of its rear recess, the base 11 delimits a rear surface 11b, which is inscribed in a plane perpendicular to the X axis and which, in the example considered in the figures, extends between the branches 12 and 13.

5 [0020] The base 11 is designed to be permanently fixed to the cutting head 2, in particular

to one of its radial arms 3, as in the example shown in figure 1. This definitive fixing is carried out by any appropriate means, for example, by welding the lower face of the base 11 to a lateral edge of the arm 3 in question . In practice, the orientation of the support 10 with respect to the arm in question 3 or, more generally, with respect to the cutting head 2 is not limiting of the invention.

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[0021] On its side directed towards the branch 13, the branch 12 delimits a lateral surface 12A, which is inscribed in a plane perpendicular to the Y axis and which, in the example considered in the figures, extends along the entire extension of the branch 12 along the X and Z axes. In the same way, on its side directed towards the branch 12, the branch 13 delimits a lateral surface 13A, which is inscribed in a plane perpendicular to the Y axis and which, in the

As an example considered in the figures, it extends over the entire extension of the branch 13 along the X and Z axes. As is clearly visible in Figures 7 and 8, the lateral surfaces 12A and 13A are thus facing each other according to the Y axis.

[0022] On its side side opposite its surface 12A, the branch 12 delimits a housing 14 that is cylindrical, with a circular base and centered on a Y1 axis parallel to the Y axis. The housing 14 is thus hollow on the side face

20 of the branch 12, opposite to the branch 13. As is clearly visible in Figures 3 and 4, the branch 12 also delimits a groove 15 which, at the same time, joins along the Z axis the housing 14 to the upper face of the branch 12 and joins, along the Y axis, the bottom of the housing 14 to the lateral surface 12A of the branch 12. This groove 15 has a smooth wall and has a width, that is, a dimension along the X axis, which is strictly smaller than the diameter of the housing 14.

[0023] The branch 13 defines a through hole 16, with a smooth wall that joins the surface

lateral 13A to the lateral face of the branch 13, opposite to the branch 12. This through hole 16 extends over the Y axis, being centered on the Y1 axis, as is clearly visible in Figures 7 and 8.

[0024] Furthermore, as is clearly visible in Figures 3 and 5, branches 12 and 13 delimit respective front surfaces 30 12B and 13B, which are inscribed in the same plane perpendicular to the X axis and which, in the example

considered in the figures, they extend over an upper part of these branches.

[0025] As is clearly visible in Figures 3 and 4, the tooth 20 comprises a front head 21 extended backwards by a body 22, giving the tooth 20 a "T" shape when viewed along the Z axis.

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[0026] On its front side, the head 21 is designed to attack the ground to be excavated, by scraping to tear off the debris. To this end, in a manner known per se and not limiting the invention, the front part of the head 21 is rigidly provided with inserts 23 of hard material, such as carbide, or more generally, of functionally similar resistant elements with a view to intensifying the scraping action

40 tooth 20 against the digging front.

[0027] In the rear part, the head 21 delimits, on either side, according to the Y axis, of the body 22, rear surfaces 21A and 21B, which are inscribed in the same plane perpendicular to the X axis and which, in the example of embodiment considered here, occupy the entire rear face of the head 21 outside the area of the body 22. Also, as

45 indicates in figures 5 and 6, the head 21 delimits, on its lower side, a lower surface 21C, which is inscribed in a plane perpendicular to the Z axis and which, in the exemplary embodiment considered here, occupies a front part of The underside of the head.

[0028] As is clearly visible in Figures 3, 4 and 6, the body 22 is provided, at its rear end, with a lower heel 24 which, in conjunction with the rest of the body 22, forms a downwardly directed elbow . Heel 24 defines this way

a front surface 24A, which is inscribed in a plane perpendicular to the X axis and which, in the exemplary embodiment considered here, extends substantially over the entire front face of the heel.

[0029] The body 22 delimits lateral surfaces 22A and 22B, opposite each other along the Y axis, which are each inscribed in planes perpendicular to the Y axis and which, in the example of embodiment considered herein, occupy

substantially all the extension of the corresponding lateral faces of the body 22.

[0030] The support 10 and the tooth 20 are shaped to engage with each other so that they block, except for functional games, any relative movement between them except a movement towards

above along the Z axis of the tooth relative to the support. For this, as shown in Figures 2 and 5 to 8, the tooth 20 is designed to be mounted on the support 10 so that its body 22 is received between the branches 12 and 13 and its head 21 is received at the front of these branches while its heel 24 is received in the rear recess of the base 11. In this assembled state of the tooth 20 on the support 10, the lower surface 5 21C of the head 21 is in flat contact against the upper surface 11A of the base 11 so that the tooth is locked down along the Z axis with respect to the support 10. Furthermore, the distance, according to the X axis, between the rear surfaces 21A and 21B of the head 21 and the front surface 24A of the heel 24 it is the same, except for a functional play, at the distance along the X axis, between the rear surface 11B of the base 11 and the front surfaces 12B and 13B of the branches 12 and 13: in the mounted state of the tooth 20 on the support 10, surfaces 10 24A, 21A and 21B are, except for the aforementioned play, in flat contact with respectively the surfaces 11B, 12B and 13B so that the tooth 20 and the support 10 are locked relative to each other at the same time forward and backward along the axis X, as shown in Figures 5 and 6. In addition, the dimension, according to the Y axis, of the body 22 is equal, except for a functional play, to the separation, according to this Y axis, between the branches 12 and 13: in the assembled state of the tooth 20 on the support 10, the lateral surfaces 22A and 22B of the body 22 are, except for the aforementioned play, in flat contact with respectively the lateral surfaces 12A and 13A of the branches 12 and 13 so that the tooth 20 and the support 10 are locked with respect to each other in the two directions, opposite each other, extending along the Y axis.

[0031] Thus, in the assembled state of the tooth 20 on the support 10, the tooth 20 and the support 10 cooperate, in 20 all spatial directions except upward along the Z axis, by complementarity of shapes

which are fixedly joined to each other, by blocking between surfaces 21A, 21B, 21C, 22A, 22B and 24A and surfaces 11A, 11B, 12A, 13A, 12B and 13B. It is also understood that separating the tooth 20 from the support 10 for the disassembly of the tooth is only possible in an uncoupling direction D, which is rectilinear and is oriented in one direction and which, in the example considered here and as indicated by an arrow in figure 4, it extends along the Z axis and is oriented upwards.

[0032] In addition, as shown in Figures 3, 7 and 8, the body 22 of the tooth 20 delimits a through hole 25 which extends along the Y axis, joining the side surfaces 22A and 22B to each other. This hole 25 is centered on an axis Y2 and is provided with a thread 26 which, in the exemplary embodiment considered here,

30 extends over the entire axial length of the hole 25. In the assembled state of the tooth 20 on the support 10, the hole 25 extends in the extension, along the Y axis, of the housing 14 and of the hole 16 of the branches 12 and 13, thus merging the Y1 and Y2 axes, as shown in Figures 7 and 8.

[0033] As shown in Figure 3, the screw 30 defines a central longitudinal axis Y3 which, in service, is understood along the Y axis. This screw 30 includes centered on the Y3 axis:

- at a longitudinal end 30A, a head 31 provided with a receiving fingerprint of a tool, not shown, of driving the screw 30 rotating on itself about the axis Y3;

- at its opposite longitudinal end 30B, a smooth surface pin 32, in particular non-threaded; Y

40 - in its current part 30C, a connecting rod 33 between the head 31 and the pin 32, which is provided with a fillet 34, which extends over most of this rod, and which has a diameter at the same time strictly inferior to that of head 31 and strictly superior to that of pin 32.

[0034] The filleting 34 of the screw 30 is complementary to the threading 26 of the tooth 20, so that, as shown in Figure 4, the hole 25 of the tooth 20 is designed to receive the screw 30 mobilely, by

screwed unscrewed between the thread 34 and the thread 26, thus merging the Y2 and Y3 axes. Thus, while maintaining solidarity with the tooth 20, the screw 30 is movable with respect to the tooth along the Y axis, by means of its rotation drive on it.

[0035] Screw 30 is intended to fix tooth 20 to support 10, not in the sense that this screw 30

would rigidly join the tooth 20 and the support 10 to each other by transmitting the forces between them in all directions, but in the sense that the screw 30 is designed to block the tooth 20 with respect to the support 10 only in the disengagement direction D, thus fixing the assembled state of the tooth 20 in the support 10. For this, while the tooth 20 is in a state mounted on the support 10, the head 31 of the screw 30 is 55 designed to be received inside the housing 14, this the latter being provided in a complementary manner to the head 31, and the pin 32 of the screw 30 is designed to be received in the hole 16, the latter being provided in a complementary manner to the pin 32: by complementarity of shapes between, on the one hand, the head 31 and housing 14, and on the other hand, pin 32 and hole 16, except for functional sets, screw 30 is in potential interference between the support in all you give the radial directions to the Y1 and Y3 axes that are

then substantially merged. However, because of the gear, by blocking, between the support 10 and the tooth 20, described above, the screw only mechanically interferes with the support 10 in the disengagement direction D, that is upwards along the Z axis, this interference in the direction of decoupling D also occurring exclusively between the screw and the support in the sense that, in this direction of decoupling D, the support and the tooth are not directly engaged with each other.

[0036] The relative distribution just described, between the support 10, the tooth 20 and the screw 30,

corresponds to an assembled configuration of the excavation tool 4, illustrated by figures 2 and 5 to 7: in this assembled configuration, as explained above, the screw 30 interferes with the support 10 10 only in the decoupling direction D to block the tooth 20 with respect to the support, while, in the other directions other than this decoupling direction D, the tooth is mechanically engaged directly with the support. In this way, the efforts exerted on the tooth 20 when the tool 4 scratches the excavation front against which the cutting head 2 is applied, are transmitted directly to the support 10, without passing through the screw 30, except for the oriented forces rigorously in the direction of disengagement D. It is understood that, without penalizing the fixation of the tooth 20 in the support 10 and, more generally, the reliability of the digging tool 4, the screw 30, even provided in a single copy in this Excavation tool is sufficient, without any other means of fixing than this single screw being advantageously necessary.

[0037] For tool 4 to move from its mounted configuration to a disassembled configuration, such

As illustrated in Figures 4 and 8, the screw 30, by dragging its head 21 with the help of an ad hoc tool not shown, unscrews the tooth 20 so that, according to the Y axis, the head 31 is removed of the housing 14 and the pin 32 of the hole 16. This unscrewing of the screw 30 continues until the head 31 of the housing 14 and the pin 32 of the hole 16 are completely removed, as shown in Figure 8, 25 without thereby removing the screw 30 of the threaded hole 25 of the tooth 20, keeping a part of the fillet 34 inserted with a part of the thread 26. The tooth 20 and the screw 30 can then be completely disengaged from the support 10, being dragged, manually or with tools appropriate, upward along the Z axis, or, in other words, only in the direction of decoupling D, as shown in Figure 4. Of course, so that the screw 30 does not block the relative decoupling between the support e 10 and the assembly constituted 30 by the tooth and the screw 30, the latter must not interfere with the support 10 in the disengagement direction D, which goes through an ad hoc dimensioning of its groove 15, the length of this groove, that is to say, its dimension along the X axis, being greater, at least except for a functional clearance, to the diameter of the pin 33, as is clearly visible in Figure 5.

[0038] The passage of tool 4 from the disassembled configuration to the mounted configuration is carried out in

inversely to what has just been described for the passage of the assembled configuration to the disassembled configuration, by successively, the complete assembly of the assembly, constituted by the tooth 20 and the screw 30, on the support 10 by dragging of this assembly only in a direction opposite to the disengagement direction D, followed by screwing the screw 30, until the complete penetration of its head 31 in the housing 14 and its pin 32 in the hole 16. In practice, this screwing is applied until that the head 31 stops, according to the Y axis, against the bottom of the housing 14. The continuation of this screwing is prevented, except for a functional play, by blocking, on the Y axis, of the surface 22A of the body 22 against the surface 12A of the branch 12 of the support 10, but advantageously allows to clamp the screw 30 thanks to the tightening of the branch 12 between the head 31 of the screw and the body 22 of the tooth: the risk of unscrewing or unexpected, the screw 30 is thus limited 45 because an unlocking effort of the screw is necessary to start unscrewing so that the tool 4 passes to a disassembled configuration.

[0039] In all cases, the passage of the excavation tool 4 between its assembled and disassembled configurations is simply done by screwing-unscrewing the screw 30, keeping the tooth 20

50 solidarity: the corresponding manipulations are quick and easy to carry out, where appropriate automatically by a manipulator robot, without running the risk of losing the screw. Also, once the excavation tool 4 is in the disassembled configuration, the complete disengagement of the support 10 of the tooth 20 and of the screw 30 that is partially screwed, as well as the mounting on the support of this assembly constituted by the Tooth and screw are carried out by dragging this assembly exclusively in parallel to the disengagement direction D, respectively in the direction of this disengagement direction and in the opposite direction: the respective manipulations are still fast and easy to carry. out, where appropriate automatically by a manipulator robot.

[0040] Finally, various arrangements and variants of excavation tool 4 and

of the TBM 1 described so far. As examples:

- instead of being through, the hole 16 may be blind, leading only to the lateral surface 13A of the branch 13;

5 - to facilitate the placement of the assembly, constituted by the tooth 20 and the screw 30, with respect to the support 10, certain edges of the support, the tooth and / or the screw are advantageously chamfered; in the embodiment shown in the figures, it is the case in particular of the upper edge of the lateral surfaces 12A and 13A, the lower edge of the lateral surfaces 22A and 22B, the upper edge of the rear surface 11B, the lower edge from the front surface 24A, the upper edge of the edges of the groove 15 and the extreme peripheral edge of the pin 10 32, as well as the contour of the housing 14 and the hole 16; I

- instead of being strictly perpendicular as in the exemplary embodiment considered in the figures, the decoupling direction D can, more generally, be transverse to the central axis Y2 of the threaded hole 25.

Claims (9)

1. Excavation tool (4) for a TBM (1), comprising: 5 - a tooth (20) to attack the ground to be excavated; - a support (10) for mounting the tooth, the support being provided to be permanently fixed to a cutting head (2) of the TBM, the support and the tooth being shaped to be engaged with each other so that they fixedly connect the tooth with the support in all spatial directions except in an uncoupling direction (D); Y 10 - a screw (30) for detachable fixing of the tooth to the support, the screw being provided with a thread (34) that is screwed into a thread (26) of the tooth, the decoupling direction (D) being transverse to the central axis ( Y2) of this thread; in which, in a mounted configuration of the digging tool (4), the tooth (20) is mechanically engaged directly with the support (10) in the other directions other than the decoupling direction (D) and the screw (30) interferes with the support in the direction of decoupling (D) to block the tooth from the support; characterized in that the threading (26) of the tooth (20) and the filleting (34) of the screw (30) are designed to, by screw-unscrewing, keep the tooth and the screw integral with one another while the digging tool (4) passes between the mounted configuration and a disassembled configuration in which the screw does not interfere with the support (10) in the decoupling direction (D) so that, by dragging only in the decoupling direction, the tooth and the Screws are decoupled from the bracket, while by dragging only in a direction opposite to the direction of decoupling, the tooth and the screw are mounted on the bracket. 25 2. Excavation tool according to claim 1, characterized in that the thread (34) of the screw (30) is located in the running part (30C) of the screw. 3. Excavation tool according to one of claims 1 or 2, characterized in that, in the assembled configuration of the excavation tool (4), the screw (30) interferes with the support (10) in the decoupling direction (D) at the level of the two opposite longitudinal ends (30A, 30B) of the screw. 4. Excavation tool according to claim 3, characterized in that one first (30A) of the two ends of the screw (30) forms a head (31) for driving the screw into screw-unscrew with respect to the Threading (26) of the tooth (20), said head being attached to the second end (30B) of the screw by a stem (33) of the roll, whose diameter is strictly smaller than that of the head, and because the support (10) delimits accommodation (14): - inside of which the head (31) of the screw (30) is received in a complementary manner in the mounted configuration of the excavation tool (4); 40 - from which the screw head comes out completely during unscrewing so that the excavation tool passes from its mounted configuration to its disassembled configuration; Y - which is connected to an outer face of the support (10) in the disengagement direction (D) by means of a groove (15) of the support whose width is simultaneously smaller than the diameter of the head (31) of the screw (30) and greater than the diameter of the stem (33) of the screw. Four. Five 5. Excavation tool according to claim 4, characterized in that the groove (15) of the support (10) also joins the housing (14) to a surface (12A), delimited by the support, to block the tooth (20) in a direction parallel to the central axis (Y2) of the threading (26). 50 6. Excavation tool according to one of claims 4 or 5, characterized in that the second end (30B) of the screw (30) forms a smooth pin (32), and because the support (10) delimits a smooth hole (16), inside which the pin (32) of the screw (30) is received in a complementary manner in the mounted configuration of the digging tool (4), and from which the screw pin comes out completely during unscrewing of the screw so that the excavation tool passes from its mounted configuration to its 55 configuration removed. 7. Excavation tool according to any of the preceding claims, characterized because, in the assembled configuration of the digging tool (4), the tooth (20) and the support (10) are, in other directions different from the disengagement direction (D), mechanically engaged with each other by contact between blocking surfaces (11A, 11B, 12A, 12B, respectively delimited by the tooth and the support. 8. Excavation tool according to claim 5 blocking include: - a surface (21C) of the tooth (20) and a surface (11A) of the support (10), which, in the assembled configuration of the digging tool (4), are in contact with each other to block the tooth with respect to the support in the opposite direction to the decoupling direction (D); 10 - surfaces (22A, 22B) of the tooth (20) and surfaces (12A, 13A) of the support (10) which, in the assembled configuration of the digging tool, are in contact with each other to block the tooth and the support with respect to each other in the directions, opposite each other, which are parallel to the central axis (Y2) of the threading; Y - surfaces (21A, 21B, 24A) of the tooth (20) and surfaces (12B, 13B, 11B) of the support (10) which, in the mounted configuration of the excavation tool, are in contact with each other to block the tooth and the 15 support each other in the directions, opposite each other, which are perpendicular, at the same time, to the decoupling direction (D) and to the central axis (Y2) of the threading (26). 9. Excavation tool according to any of the preceding claims, characterized in that the screw (30) is provided in a single copy, and that the excavation tool (4) is 20 devoid of any other means of fixing the tooth (20) to the support (10) more than this single screw. 10. TBM (1), comprising: - a cutting head (2); Y 25 - at least one excavation tool (4), which is in accordance with any of the preceding claims and whose support (10) is permanently attached to the cutting head (2). 13A, 13B, 21A, 21B, 21C, 22A, 22B, 24A) 7, characterized in that said surfaces of