EP0020272B1 - Mobile tool holder for working a tube sheet - Google Patents

Description

The present invention relates to a tool holder device intended to be remotely controlled on the move on a tubular plate. It applies more particularly to the maintenance service for a steam generator in a nuclear power plant.

In a pressurized water nuclear power plant, the very large number of tubes in the tubular bundles of steam generators must be subject to periodic verification and maintenance operations, such as, for example, welding operations, fitting plugs. obturation to neutralize defective tubes, or interventions on the inner lining of the tubes. These maintenance operations must be carried out from the water box, that is to say in a highly radioactive field; it is therefore necessary to use remote-controlled devices to limit human intervention to the simple installation of equipment. In addition, the steam generators are generally with vertical tubes, that is to say that the tube plate is then "at the ceiling of the water box.

Apparatuses capable of being moved by remote control have already been produced under the tube plate of a steam generator. Patent application FR-A-2309314 describes such an apparatus comprising two perpendicular arms provided with hooking means in the orifices of the plate, and comprising means for giving the arms relative movements parallel and perpendicular to the tube plate to allow a step-by-step movement of the assembly, by successively hooking each of the arms and moving the other while one is hooked.

However, such an apparatus is of use limited to the installation of guides for control probes to be introduced into the tubes, these guides being necessarily arranged at the end of the arms because of the space requirement of the central part of the device. This is without disadvantage for simple guides, but does not allow the use of more complex and heavier tools, such as for example milling or welding heads.

The present invention overcomes these drawbacks by making it possible to produce an apparatus, also with automatic movements remotely controlled on a tubular plate by relative movements of two perpendicular arms, but which can also be used as a support for various tool heads necessary for the maintenance of the plate and the tubes connected to it.

According to the invention it comprises a support body at an angle forming a dihedral whose edge is perpendicular to the tube plate, each arm being carried, independently of one another and in the external dihedral, by a slide parallel to the plate, itself mounted on a mobile carriage on the body perpendicular to the plate, with independent remote-controlled means to move each arm on its slide and each carriage on the body: in the inner dihedral, free of arm movement, the body includes guides for supporting tools moving perpendicular to the tube plate.

According to a preferred embodiment, at the end of the body opposite to the tube plate, the apparatus comprises a rotating turret with support guides for several tools, and means for selectively bringing into the inner dihedral of the body one or the other of the heads on standby, the support guides then being in the extension of the dihedral guides, the apparatus being moreover provided with means for moving the tools on the guides of the inner dihedron.

• La figure 1 est une vue en élévation du porte-outil proprement dit, selon H de la figure 3.
• La figure 2 est une autre vue en élévation selon II-II de la figure 3.
• La figure 3 est une vue de dessus du dispositif, selon III-III de la figure 2.
• La figure 4 est une coupe selon IV-IV de la figure 2.
• La figure 5 est une vue simplifiée en perspective, dans le cas d'un dispositif utilisant un seul outil à télécommande manuelle.
• La figure 6 est une vue en élévation, et partiellement en coupe, de la partie inférieure du porte-outil représenté à la figure 2, lorsque celui-ci est équipé d'une tourelle porteuse de plusieurs types d'outils interchangeables.
• La figure 7 est une vue homologue de la figure 5, dans le cas d'un appareil à tourelle.

The invention will be better understood by referring to particular embodiments given by way of examples and represented by the appended drawings.

• FIG. 1 is an elevation view of the tool holder proper, along H of FIG. 3.
• FIG. 2 is another view in elevation along II-II of FIG. 3.
• FIG. 3 is a top view of the device, according to III-III of FIG. 2.
• Figure 4 is a section on IV-IV of Figure 2.
• Figure 5 is a simplified perspective view, in the case of a device using a single tool with manual remote control.
• Figure 6 is an elevational view, partially in section, of the lower part of the tool holder shown in Figure 2, when the latter is equipped with a turret carrying several types of interchangeable tools.
• Figure 7 is a counterpart view of Figure 5, in the case of a turret apparatus.

By first referring to all of Figures 1 to 4, we will see that the body of the tool holder is mainly constituted by two plates 1 and 2 welded at right angles to each other, and welded to their lower part of a substantially square plate 3.

The plate 1 supports a block of ball runners 5 in which slides a carriage 6 linked to the head of the rod 7 of a jack 8. The body of the jack 8 is articulated at 9 on an extension of the foot of the board 2 and on an auxiliary support 10. The carriage 6 carries a set of four idle rollers 12 between which an arm 13 can slide, the central part of which has a cross-section with the profile of the rollers. At each of its ends, the arm 13 carries a jack 15 for controlling expandable clamps 16, represented here engaged by their expandable part in the orifices of the tubular plate 18. These clamps may for example be of the type shown in more detail in the application. from previous French patent 2309314. The jack body 20 is secured to the end of the arm 13 and its rod 21 is linked to an extension 22 of the carriage 6.

In a completely analogous manner, the plate 2 supports a block of ball bearing slides 25 in which slides a carriage 26 linked to the head of the rod 27 of a jack 28. The jack body 28 is fixed on the support 29 welded to plate 2.

The carriage 26 carries a set of four idler rollers 32 between which an arm 33 can slide. At each of its ends, the arm 33 carries a jack 35. For controlling grippers 36 engaged in the orifices of the tubular plate 18. The body cylinder 40 is integral with the end of arm 33, and its rod 41 is linked to an extension 42 of carriage 26.

It can be seen, in particular in FIGS. 3 and 4, that the inner dihedral formed by the plates 1 and 2 of the body is left entirely free by the movement of the arms 13, 33, as well as by the operation of their control jacks. This area can therefore be used to bring a tool head against the plate. For this each plate 1 and supports a guide 45 and 46, parallel to the edge of the dihedral, that is to say perpendicular to the tube plate when the tool holder is in place.

We will now refer to Figure 5 where we see an automatic argon welding head in place in the dihedral. The actual welding head 50 is carried by a base 51 secured to a slide 52 engaged on the guides 45 and 46. Here the maneuver for bringing the head into the working position on the tube plate, that is to say -to say the movement maneuver on the guides 45 and 46, is carried out by manual remote control from the outside of the water box. The rigid guides 45 and 46 are respectively extended by flexible guides 53 and 54, of a length such that their other end is always outside the water box regardless of the position of the device on the tube plate . They are joined at their ends by the spacer 55 which retains the same distance between the flexible guides as between the rigid guides 45 and 46. The spacer 55 carries a handle 56. Each guide 53 and 54 passes inside d 'a sheath 57 and 58 flexible, but rigid in axial compression, the two sheaths being connected at each end by a spacer 60 and 61, the latter provided with a handle 62. Finally the spacer 60 is linked to the base 51 by a beam 64 flexible but rigid in compression.

We see that by pushing or pulling on the handle 62 and taking reaction on the spacer 55 or the handle 56, we can move at will the head 50 on the guides 45 and 46 relative to the tube plate when the together was placed in position on the plate, so that the head is opposite the tube on which one wishes to intervene.

The sheath 65 contains the cables or tubes for the remote control of the actual scudure head. The sheath 66 contains cables or tubes for remote control of the cylinders 8, 20, 28 and 40. for moving the arms, that is to say for moving the tool holder on the plate, as well as actuating cylinders 15 and 35 hanging clips. We finally see that it is possible to change tools without detaching the tool holder from the tube plate. It will then suffice to release the spacer 55 in order to be able to completely pull on the handle 62 and extract from the water box the whole of the head 50 and of its carrying slide 52 which will be guided outwards by the flexible guides 53 and 54. We can then engage by the same channel another slide carrying another tool, milling or drilling head for example, which can in turn be brought into the working position against the plate.

The tool changing system can be improved by using a tool turret allowing all the tools planned for use to be placed inside the water box. Figure 6 shows the mounting of such a turret. It comprises a pivot 70 bolted under the plate 3, and on which is mounted a rotating ferrule 71 integral with the toothed ring 72. The ring and the ferrule are rotated by the pinion 73, mounted on a support 74 locked in rotation on the pivot by the rings 75 and 76, and remotely controlled by means of the flexible 77. The ferrule 71 supports the turntable 79 provided with guides 80 which are at the same center distance as the guides 45 and 46. The plate 79 comprises, angularly distributed around the axis, three or four sets of two guides 80.

If, by rotation of the turret and the plate 79, the slide 52 is brought from its standby position to an active position in the dihedral of the body, the guides 80 will be in the extension of the guides 45 and 46, as can be seen in FIG. 7. The tool holder is also provided here, in the working dihedron, with a screw lifting mechanism comprising a motor 82 driving a vertical screw 83 which then engages in a conjugate nut carried by the slide 52. The remote control of screw 83 allows the entire welding head to be brought into the active position against the tube plate. To change the tool, it suffices to lower the head on its support guides 80 of the turntable, then rotate the latter to bring another head into the dihedral and make it rise to the working position by means of screw 83.

We can also note that we can also use a screw mechanism 82-83 in the case of Figure 5 for a device without a rotating turret. The head holder slide is then hung by hand until it engages the screw, and precise positioning and vertical working movements can be obtained by electric remote control.

Of course, the invention is not strictly limited to the embodiments which have just been described by way of examples, but it also covers the embodiments which would differ therefrom only in details, in variant embodiments or by the use of equivalent means.

We could thus conceive of completing the installation described by stabilization pads located at the ends of the arms to strengthen the support of the device on the tube plate.

We could also provide the device with a support plate secured to the body and provided with movable fingers capable of engaging in holes in the plate; such an arrangement will make it possible to avoid making the coupling torques bear the reaction torques generated by rotary tools such as milling cutters or drills put into action on the plate or the tubes.

Finally, the invention would apply in the same way regardless of the arrangement of the tube plate which could as well be vertical or inclined.

Claims (4)

1. Toolholder device able to move on a tubular plate (18) and comprising two arms (13, 33) at right angles to one another, which are provided with remotely controlled members (16, 36) for engagement in the apertures in the plate (18), with remotely controlled means (8, 28, 20, 40) for imparting to the arms (13, 33) relative movements parallel and at right angles to the tubular plate (18) in order to permit step-by-step displacement of the assembly by successive engagement of each of the arms (13, 33) and displacement of the other arm while one of them is engaged, characterised by the fact that it comprises a right-angled support body (1, 2) forming a dihedron whose corner is at right angles to the tubular plate (18), each arm (13, 33) being carried independently of the other and in the external dihedron by a carriage (6, 26) which in turn is mounted on a slide guide (5, 28) movable on the body (1, 2), with the independent remotely controlled means (8, 28, 20, 40) for displacing, paralled to the plate (18), each arm (12, 33) on its carriage (6, 26) and each slide guide on the body (1, 2) at right angles to the plate (18), and by the fact that in the internal dihedron, free from the movement of the arms (13, 33), the body (1, 2) is provided with guides (45, 46) for supporting th tools in their displacement at right angles to the tubular plate (18).

2. Toolholder device according to Claim 1, characterised by the fact that it is provided with means (55, 61) for displacing the tools (50) on the guides (45, 46) of the internal dihedron.

3. Toolholder device according to Claim 2, characterised by the fact that it is provided at the opposite end of the body to the tubular plate (18) with a rotating turret (79) having support guides (80) for a plurality of tool heads, and means (73) for selectively bringing one or other of the heads (50) standing by into the internal dihedron of the body, the support guides (80) then being in line with the guides (45, 46) of the dihedron.

4. Toolholder device according to any of the preceding claims, characterised by the fact that it is provided with a reaction plate fixed to the body and equipped with movable fingers having means for their engagement in apertures in the tubular plate or for withdrawing them therefrom.

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