EP1010856A1 - Tunnel boring machine - Google Patents

Abstract

The tunnelling machine, consisting of rear and front (3) shields connected by floating joints, and a front shield cutting face (4) in the form of a circular plate (5) with cutters (7). The machine has at least one power cylinder (20) set parallel to its lengthwise axis and comprising a fixed section (21) on the machine and a moving section (22) which can be moved between a retracted position and an active position in which it makes contact with the working rock face and allows the front shield and cutting face to be retracted independently of the rear shield.

Description

The present invention relates to a machine digging a tunnel called a tunnel boring machine, which has a large mobile structure called a shield having a substantially circular section whose diameter corresponds to the diameter of the tunnel for which the digging.

Generally, the shield is formed by an envelope cylindrical in two parts, a first part called rear bumper and a second part called bumper front connected to said rear bumper by a system floating joints to allow relative movements low amplitudes.

The front bumper carries a cutting head which comes into contact with the working face to achieve the cutting of the formation crossed by the tunnel and which present in the general form of a circular tray of same diameter as the shield.

The cutting head is equipped with a set of tools constituted for example by wheels or tools planers or other, depending on the nature of the terrain crossed.

The felling of the ground is obtained by rotation of the cutting head and simultaneously by a push of this cutting head against the cutting face.

During the advancement of the digging machine, the cutting tools are subject to wear so that is necessary to replace them after a while of use or after a certain length of digging.

This tool replacement operation requires in many cases move the cutting head back a few centimeters to a few decimeters depending on the type of tools and depending on the type of attachment of these tools to the cutting head.

For this purpose, we know several kinds of machines tunnel excavation which include means for receding of the cutting head.

In some cases, the front shield which carries the cutting head is equipped with stabilizers and possibly auxiliary fasteners on the wall of the excavated hole and which allow to block this front shield.

The rear bumper is also equipped with organs lateral hooks which rest on the walls from the excavated hole and securely block this front bumper.

The rear bumper is connected to the front bumper by double-acting hydraulic cylinders which, in combination with the hooking members, allow movement step-by-step shields and the whole TBM as well that the recoil of the front bumper and the cutting head for change tools.

In other cases, the cutting head and means for driving the latter in rotation are mounted on an axial translation device relative to the shield.

This device consists of one or more slides and is operated by hydraulic cylinders double effect.

This translational movement of the cutting head is used to clear this cutting head from the front of pruning before replacing worn tools.

In case the front bumper is connected to the rear bumper by a set of articulation jacks, he is also known to back off the shield front and cutting head, use these cylinders.

But, to carry out this operation, the shield rear must be fitted with lateral hooks on the walls of the tunnel.

The installation of such attachment devices on the rear bumper has technical drawbacks and important economic.

Indeed, the installation of such fastening members on the rear bumper requires lengthening of this and above all causes the unfavorable positions of thrust cylinder attachments on the front bumper which can interfere with essential functions, such as the orientation of the front bumper and the cutting head when digging the tunnel.

The invention aims to avoid these drawbacks.

The invention therefore relates to a machine for tunneling, of the type comprising a formed shield by a rear shield and by a front shield, connected to each other by a set of floating joints, said front shield carrying a cutting head formed by a circular plate driven in rotation and fitted with tools work, characterized in that it comprises at least one jack arranged parallel to the longitudinal axis of the machine digging and comprising a fixed part integral with said digging machine and a movable movable part in translation between a retracted position and a position active in contact with the working face to move back said front shield and said cutting head, regardless of rear bumper.

• la machine de creusement comporte deux vérins s'étendant parallèlement l'un par rapport à l'autre et à l'axe longitudinal de ladite machine de creusement pour reculer le bouclier avant et la tête de coupe,
• la partie fixe dudit vérin est solidaire du bouclier avant,
• la partie mobile dudit vérin traverse, en position active, le plateau circulaire de la tête de coupe,
• l'extrémité libre de la partie mobile dudit vérin comporte un patin d'appui sur le front de taille, monté oscillant sur ladite extrémité,
• la partie fixe dudit vérin est solidaire de la tête de coupe,
• la partie fixe dudit vérin est formée par une chemise externe et un guide central concentrique à ladite chemise externe et ménageant avec celle-ci un espace libre dans lequel se déplace la partie mobile de ce vérin.

According to other characteristics of the invention:

• the digging machine comprises two jacks extending parallel to each other and to the longitudinal axis of said digging machine for drawing back the front shield and the cutting head,
• the fixed part of said cylinder is integral with the front shield,
• the movable part of said cylinder crosses, in the active position, the circular plate of the cutting head,
• the free end of the movable part of said jack comprises a support pad on the cutting face, mounted oscillating on said end,
• the fixed part of said cylinder is integral with the cutting head,
• the fixed part of said jack is formed by an outer jacket and a central guide concentric with said outer jacket and providing with the latter a free space in which the mobile part of this jack moves.

• la Fig. 1 est une vue schématique en coupe axiale d'un premier mode de réalisation d'une machine de creusement conforme à l'invention,
• la Fig. 2 est une vue de face en élévation de la tête de coupe de la machine de creusement,
• la Fig. 3 est une vue en coupe selon la ligne 3-3 de la Fig. 2 montrant le bouclier avant et la tête de coupe en position de creusement du tunnel,
• la Fig. 4 est une vue identique à la Fig. 3 montrant le bouclier avant et la tête de coupe en position de recul par rapport au front de taille,
• la Fig. 5 est une vue schématique en coupe axiale d'un second mode de réalisation d'une machine de creusement conforme à l'invention
• les Figs. 6 et 7 sont des vues schématiques en coupe axiale montrant les deux portions d'un vérin de déplacement de la tête de coupe du second mode de réalisation de la machine de creusement conforme à l'invention.

Other characteristics and advantages of the invention will become apparent during the description which follows, given solely by way of example and made with reference to the appended drawings, in which:

• Fig. 1 is a schematic view in axial section of a first embodiment of a digging machine according to the invention,
• Fig. 2 is a front elevation view of the cutting head of the digging machine,
• Fig. 3 is a sectional view along line 3-3 of FIG. 2 showing the front shield and the cutting head in the tunnel digging position,
• Fig. 4 is a view identical to FIG. 3 showing the front shield and the cutting head in the retracted position relative to the cutting face,
• Fig. 5 is a schematic view in axial section of a second embodiment of a digging machine according to the invention
• Figs. 6 and 7 are schematic views in axial section showing the two portions of a cylinder for moving the cutting head of the second embodiment of the digging machine according to the invention.

In Fig. 1, there is shown schematically a digging machine 1, called a tunnel boring machine, which typically consists of an envelope generally cylindrical in two independent parts, a first part 2 called rear bumper and a second part 3 called front shield.

Front bumper 3 carries a designated cutting head as a whole by the reference 4, and which comes in contact with the face of size A to carry out the cutting of the formation crossed by the tunnel and which presents itself in the general form of a circular plate 5 likewise diameter than the rear shield 2 and that the front shield 3.

The cutting head 4 is rotated by at least one motor 6 at a determined speed which is a function the nature of the land to be dug.

The plate 5 of the cutting head 4 carries, on its front, working tools 7, such as for example slaughter tools and / or crushing wheels.

The front bumper 3 also has a partition 8 vertical and fixed, arranged behind the cutting head 4 and providing therewith a kneading chamber 9.

The rear shield 2 and the front shield 3 are connected to each other by a set of 10 joints floating which allows angular movements and of translation of this front shield 3 relative to said shield rear 2.

These floating joints are made up by hydraulic cylinders 11 called articulation cylinders which also pull the rear bumper 2 by the front shield 3.

The digging machine 1 also includes means 12 for axially moving the assembly formed by the rear shield 2, the front shield 3 and the head cutting 4, a device 13 for installing segments 14 inside of the tunnel and a screw conveyor 15 intended for the evacuation of the material torn off and mixed with an additional product in the mixing chamber 9.

The screw conveyor 15 is formed by a sheath 15a in which is arranged an endless screw 15b driven in rotation and whose free end opens to the lower part of the mixing chamber 9 for evacuation material torn off.

The segments 14 made up of plates precast concrete or cast iron curves are intended for consolidate the internal wall of the tunnel dug by the machine digging 1.

The means 12 for axially moving the shield rear 2 as well as front shield 3 and head cutting 4 are formed by a ring of cylinders 12a integral of the front shield 3 and which come to bear against the segment of the segments 14 placed inside the tunnel of so as to exert the necessary thrust on the front shield 3 excavation of the land crossed.

Variations in the direction of the cutting head 4 are obtained by thrust differences between the different cylinders 12a.

The digging machine 1 comprises at least one cylinder designated by the general reference 20 to reverse the front shield 3 and cutting head 4 a few centimeters a few decimetres to allow replacement tools 7 worn out after a certain operating time or after a certain length of advance of the tunnel.

As seen more particularly in FIG. 2, the digging machine 1 is equipped with two jacks 20 extending parallel to each other and arranged parallel to the longitudinal axis of said machine digging 1.

According to a first embodiment shown in Figs. 1 to 4, each cylinder 20 comprises a fixed part 21 integral with the front shield 3 and more particularly fixed on the internal wall 8 of this front shield 3.

Each cylinder 20 also includes a part mobile 22 which is movable in translation parallel to the longitudinal axis of the digging machine 1. The end free 22a of the movable part 22 of the jack 20 comprises a shoe 23 mounted oscillating on said end 22a.

The jacks 20 are hydraulic jacks or tires and are supplied with pressurized fluid by a pipe, not shown.

The mobile part 22 of each cylinder 20 is displaceable between a retracted position, as shown in Fig. 3, and an active position, as shown in Fig. 4, in which the mobile part 22 crosses the plate 5 of the cutting head 4.

In this position, the oscillating pad 23 comes resting on the size A front to move the shield back front 3 and the cutting head 4, independently of the shield rear 2.

The oscillating mounting of the shoe 23 on the part mobile 22 of the corresponding jack 20 allows this shoe 23 to apply correctly on the size A face despite the irregularities of it.

The retreat of the assembly constituted by the shield front 3 and the cutting head 4 is produced in the following manner.

First, the thrust cylinders 12 are closed to avoid any uncontrolled recoil of the digging machine 1.

Then, the plate 5 of the cutting head 4 is placed in the desired position to allow passage of the mobile part 22 of each jack 20.

The cylinders 20 are actuated in such a way that the pads 23 come to bear on the cutting face A with a force controlled and maintained to allow the recoil of the front shield 3 and of the cutting head 4 to the position desired.

When this position is obtained, the cylinders 20 are arrested.

To avoid or limit the risk of inadvertent recoil of the rear bumper 2, the articulation cylinders 11 are put on the tarp and the rear shield 2 is propped up against the segments 14 placed on the wall of the tunnel by example by cylinders 12.

Maintaining the rear bumper 2 during recoil of the cutting head 4 and the front shield 3 can also be achieved by means of a supply device articulation cylinders 11 which controls the reentry of these jacks simultaneously with the backward movement of the shield front 3 and cutting head 4 with controlled effort to avoid moving the rear bumper 2.

According to a second embodiment shown in Figs. 5 to 7, the digging machine 1 comprises at minus one cylinder designated as a whole by the reference 30 and which is integrated directly into the cutting head 4 for move back the front shield 3 and this cutting head 4.

For this purpose, the jack 30 comprises a part fixed 31 secured to the cutting head 4 and a movable part 32 movable in translation parallel to the longitudinal axis of the digging machine 1 between a retracted position, as shown in Fig. 6 and an active position, as shown in Fig. 7, in which the front face of this movable part 32 is supported on the front of size A to move back the front shield 3 and said head section 4.

Thus, as shown in Figs. 6 and 7, the fixed part 31 of the cylinder 30 consists of an external jacket 31a fixed on the cutting head 4 and a central guide 31b concentric with said outer jacket 31a and sparing with this a free space in which the part moves mobile 32.

The central guide 31b is formed by a rod of diameter smaller than the internal diameter of the moving part 32 and which has at its front end a head 31c of diameter substantially equal to the internal diameter of said mobile part 32. The head 31c delimits in the internal space, two chambers 33a and 33b which are each connected to a supply line 34a and 34b respectively pressure fluid delivery.

To move the moving part 32 towards the front of size A in order to move back the front shield 3 and the head section 4, pressurized fluid is admitted into the chamber 33a through the pipe 34a.

To return the mobile part 32 to its position retracted, the pressurized fluid is admitted into the chamber 33b via line 34b causing the backflow of the fluid contained in chamber 33a via line 34a.

The means of retreating from the assembly formed by the front shield 3 and the cutting head 4 of the machine 1 according to the invention are particularly simple to implement and avoid any installation of organs additional rear bumper locks 2.

These recoil means can be adapted to all types of digging machine.

Claims (7)

Tunneling machine, of the type comprising a shield formed by a rear shield (2) and by a front shield (3) connected to each other by an assembly floating joints (10, 11), said shield front (3) carrying a cutting head (4) formed by a plate circular (5) driven in rotation and provided with work (7), characterized in that it comprises at least one cylinder (20; 30) arranged parallel to the longitudinal axis of the digging machine (1) and comprising a part fixed (21; 31) integral with said digging machine (1) and a mobile part (22; 32) movable in translation between a retracted position and an active position in contact with the front face to move said front shield back (3) and said cutting head (4), independently of the shield rear (2). Digging machine according to claim 1, characterized in that it comprises two jacks (20; 30) extending parallel to each other and to the longitudinal axis of the digging machine (1) for reversing said front shield (3) and said cutting head (4). Digging machine according to claim 1 or 2, characterized in that the fixed part (21) of said cylinder (20) is integral with the front shield (3). Digging machine according to any one of the preceding claims, characterized in that in position active, the movable part (22) of said cylinder (20) passes through the circular plate (5) of the cutting head (4). Digging machine according to any one of the preceding claims, characterized in that the end free (22a) of the movable part (22) of said cylinder (20) comprises a shoe (23) for supporting the waist face, mounted oscillating on said end (22a). Digging machine according to claim 1 or 2, characterized in that the fixed part (31) of said cylinder (30) is integral with the cutting head (4). Digging machine according to claim 6, characterized in that the fixed part (31) of said cylinder (30) is formed by an outer jacket (31a) and a guide central (31b) concentric with said outer jacket (31a) and creating with it a free space in which to move the movable part (32) of this jack (30).

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