DE2719065A1 - SCREW TOWER FOR SCREWING IN AND SCREWING LARGE BOLTS - Google Patents

Description

Patent attorneys Dipl.-lng. Curt Wallach Dipl.-Ing. Günther Koch Dipl.-Phys. Dr Tino Haibach Dipl.-Ing. Rainer Feldkamp

D-8000 Munich 2 ■ Kaufingerstraße 8 ■ Telephone (0 89) 24 02 75 ■ Telex 5 29 513 wakai d

Date: April 21. 1977

Our reference: 15 868 - Fk / Ne

Description!

Screw tower for screwing in and Unscrewing large screw bolts

Applicant:

SKF COMPAGNIE D'APPLICATIONS MECANIQUES

Clamart / France

Representative:

Dipl.-Ing. C. Wallach Dipl.-Ing. G. Koch
Dr. T. Haibach
Dipl.-Ing. R. Feldkamp 8000 Munich 2

Inventor:

Georges BOUDET
Alain NERON
Jacques CHARPENTIER
Jean-Claude DESMOULINS

709845/1050

The invention relates to a screw tower for screwing in and unscrewing large bolts, one end of which is in a fixed part, for example the edge of a Container or vessel is screwed in and the other end of which receives a nut for fastening a movable part, for example the lid of the container or vessel, the nut only then being screwed on with a low torque when the screw bolt has been tensioned with the aid of a hydraulic tensioning device, which is on the cover and its clamping force on the screw bolt with the help of an auxiliary nut or a pair of clamps that act on circular gears.

Such bolts are generally very large Number used and are relatively close together, especially for closing a reactor vessel, so that the Dismantling and reassembling a lid of the reactor vessel, unscrewing and screwing in all screw bolts in addition to tensioning with the aid of hydraulic tensioning devices, this tensioning at the same time for all screw bolts is done with the help of a known device that has an equal number of hydraulic Includes tensioning devices.

The screwing in or unscrewing of the successive bolts, which is generally done by hand, is common the longest and most difficult process.

The invention is based on the object to eliminate this disadvantage and to provide a device that in faster enables the various processes to be carried out in a fully automatic and absolutely reproducible manner, including not only unscrewing and re-screwing the bolts but also the Pulling out the screw bolts before removing the cover and inserting the screw bolts after Replace the lid.

709845/1050 ./.

27

This object is achieved according to the invention in that in a single unit, a screw device actuating a spindle with a gripping device for gripping the head of the screw bolt, which is non-rotatably connected to the spindle and on the Gohrautenbolzen both a torque and exerts an axial force at least in the direction of pull, and with one Device for axial drive and a compensation device for the joint of the screw bolt is combined, which makes it possible that the screw bolt on the internal thread of the vessel exerts a slight force, which is directed downwards when screwing in and upwards when unscrewing is, this rlraft results from the weight of the screw bolt and the effect of the compensation device.

According to one embodiment of the invention, the compensation device formed by two parallel pressure cylinders, which the entire screwing device with an adjustable force and move with a sufficient stroke so that they also act as a device for axial displacement for insertion and is used to pull out the screw bolt.

According to a further embodiment of the invention, the compensation device can be provided by a coaxial pressure cylinder be formed with a small stroke, which the gripping device with the spindle connects and rotates with these parts, the device for axial displacement then by a mechanical feed drive is formed which is synchronized with the screwing device in such a way that the forward movement per revolution equal to the thread pitch of the screw bolt is.

The entire unit is of course on an axial guide attached and this axial guide is preferably firmly connected to a carriage that move on rails can so that it can be brought successively vertically over the various bolts. The entire screw tower preferably has several identical carriages that

7Q98A5 / 1050 _{# / #}

ORIGINAL INSPECTED

271906b

work at the same time, but the number of which is less than the number of screw bolts.

The gripping device can according to an advantageous embodiment of the invention be formed by a screwdriver blade which cooperates with a slot of the screw bolt and in these under the combined action of the rotation of the spindle and the action of the device for axial displacement comes into engagement, wherein a lock is provided by means of balls fet with a groove of the screw bolt cooperate and wherein the lock is actuated by a coaxial auxiliary cylinder, which is via a rotating connection is fed.

Further advantageous refinements and developments of the invention emerge from the subclaims.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing.

In the drawing show:

Fig. 1 is a partially sectioned external view

a first embodiment of the screw tower;

Fig. 2 is a horizontal section along the line II-II

according to Fig. 1;

Fig. 3 is a partially sectioned in the axial direction

View of a second embodiment of the screw tower;

Fig. B is a partial sectional view with a larger one

Scale showing an embodiment of the gripping device.

709845/10 50 ./.

The embodiment of the screw tower shown in Fig. 1 comprises a motor 1, for example an electric motor, which drives a spindle H via a gear 2 and an electromagnetic clutch 3, which simultaneously forms a torque limiter, which can advantageously have a handwheel 5, to enable manual drive if necessary. A gripping device 6 of any kind, which makes it possible to exert a drive torque on the screw bolts in both directions of rotation and an axial force at least in the pulling direction, is connected to the spindle 4 via a coupling device 7, which enables misalignments to be compensated for.

This unit is mounted so that it can slide in a vertical guide device, for example through two vertical columns 8 and two sleeves 2 with rotating balls is formed, which are arranged on both sides of the unit as shown in FIG. On the other hand, two pressure cylinders 10 are inserted between said columns, as can also be seen from FIG. 2 and these pressure cylinders enable vertical actuation or the vertical drive of the entire unit. The pressure cylinders are preferably compressed air cylinders with regulating pressure reducing valves, which make it possible to exert an axial compensation force of the desired value. Of course this includes Value increases or decreases the weight of the entire movable unit by the desired small value depending on whether on the screw bolt this value of the force in the pulling direction during unscrewing or in the pushing direction should be exercised while screwing in.

In this embodiment, the stroke is the pressure cylinder 10 by far sufficient to cover the entire screwing path of each screw bolt, so that the same pressure cylinder can also be used for the axial movements for inserting and withdrawing the screw bolts.

709845/1050 * ^{/ #}

In the embodiment of the invention shown in FIG. 3, the two pressure cylinders 10 are replaced by a small compensating pressure cylinder 11, which is novel and which is arranged between the spindle 4 and the coupling device J along the axis of the device. It follows that the small pressure cylinder in this case does not have to compensate for the weight of the screw device, but only the weight of the gripping device 6 and the corresponding part of the spindle and the weight of the screw bolt.

On the other hand, in this case, the pressure cylinder 11 is rotatable and it is necessary to have it via a non-rotatable part 12 via a double slewing ring. on the other hand represents a coupling device which is connected by simple pins ^ "through holes in the base 14 of the pressure cylinder 11

pass through the rotary drive from the cylinder of the printing cylinder on the handwheel 5 and the lower part of the spindle. The stroke of the small pressure cylinder is also sufficient no longer sufficient to ensure the axial movement over the entire extent and this axial movement along the slide rails 8a is achieved in this case with the help of a mechanical drive device, for example is formed by two screws 15, which have a number of Chain wheels 16 and chains 17 starting from a second reduction gear 18 from the same drive motor 1 are driven, the pitch of the screws 15 as well the gear ratios of the reduction gear 18 and the chain drive are determined such that the forward movement per revolution of the unit exactly the thread height of the lower part of the screw bolt in the vessel is equivalent to. Under these conditions, the small pressure cylinder 11 only needs the small ones after starting the screwing Absorb compensating movements that are necessary to keep the axial force at the desired value.

In both embodiments, the gripping device 6 for Detecting the head of the screw bolt in advantageous

709845/1050 ./.

Way the in Flg. 4 have illustrated embodiment. In this figure, the coupling device 7 is shown, which eliminates and misalignment in the manner described formed by a flexure, a universal joint, a cross-jaw coupling or any other known device can be.

The lower part of the spindle extending from the coupling device 7 ends in a shell 20, which in its center meets a wedge 21 which integrates with a screw slot 22 which is formed at the end 23 of the screw bolt in the manner of a screwdriver slot that the shell 20 can exert driving torques in both directions. Furthermore, this shell has a certain number of openings on its cylindrical part which contain balls 24, the openings being constricted on the inner surface of the cylinder in order to prevent the wings from falling out. As can be seen from FIG. 4, the balls 24 have a diameter which is greater than the thickness of the walls of the shell 20 and the balls cooperate with a groove 24 a which is provided in the head of the screw bolt 25. On the other hand, the balls are actuated on the side of the outer cylinder surface by an actuating or locking sleeve 25 with an obliquely widened inlet opening 26, which can be moved in the axial direction with the aid of an auxiliary pressure cylinder 27, the inner piston 28 of which is axially connected to the spindle 19 via a wedge 29 and whose outer cylinder 30 can move in the axial direction with respect to this piston and actuates the locking sleeve 25, with which this outer cylinder is connected via fastening screws ^ l. In addition to these axial movements, the cylinder 30 is set in rotation together with the locking sleeve 25 and the shell 20, which feeds this

and pressure cylinder via an outer non-rotatable sleeve j52y via a requires double slewing ring. At 33 and 34 they are Feed connections for flexible pressure lines, not shown, which supply the compressed air to the pressure cylinder 27

709845/1050 _{# / #}

ORIGINAL INSPECTED

transferred and which enable unlocking and locking.

When the device hits the head of the screw bolt 23, the wedge 21 naturally does not fall under the action of force into the slot 22, so that the balls 2k are offset in the axial direction with respect to the groove 23 and cannot penetrate into this and accordingly the locking sleeve can move axially Do not lock. However, due to the rotation of the device under the action of the main motor 1, the wedge eventually enters the slot 22, whereupon the axial locking immediately takes place on the head of the screw bolt. It is then possible that the spindle 19 can exert both a tensile force and a torque on the head of the screw bolt.

The entire screwing device or screw tower is preferred mounted on a slide 35, the frame of which both the AxialfUhrungseinrichtungen 8 or 8a and the Support points for the device for axial displacement, i.e. the fastening of the ends 36 in the first embodiment the rods of the printing cylinders 10 and. in the second execution

carries the threaded holes 37/7 into the screws 15 are screwed in. The slide can be moved by a rolling motion move on rails 38 and 39, in particular from Flg. 2 can be seen, so that by this rotation on a large radius the screw tower successively perpendicular get over the axes of the various bolts can.

As mentioned above and as can be seen in part in Fig., The entire device for assembly and Dismantling a cover of a reactor vessel on a certain number of hydraulic clamping devices 4o, the number of which is equal to the number of screw bolts and which are all connected to one another via fine mounting devices that

70S845 / 1050 ^{# /} -

ORIGINAL INSPECTED

having circular support hl and hydraulic connecting lines for pressurization. Above this mounting device, an auxiliary nut unit or a locking clamping unit is arranged, which serves to transmit the tensile force of the hydraulic clamping devices to the upper end of each screw bolt, these devices preferably being controlled automatically. The above-mentioned rails that carry the screw towers are located above this entire unit.

Due to the space requirements of these screw towers or the devices for screwing in and unscrewing the screw bolts and due to the small distance between the axes the successive screw bolts it is practically impossible, apart from economic reasons, a screwing device to be used per screw bolt. However, it is appropriate to use a certain number of these screwing devices working at the same time in order to reduce the time it takes to perform this operation as much as possible. In this case, of course, the various carriages, such as 35, can be connected to one another in such a way that that they rotate in a block on rails 38 and 39 and all of them are fixed at the same time in desired locations by means of indexing devices such as 42 of FIG can. For example, if the number of slides is exactly six times less than the number of bolts, the entire screw tower unit only has to assume six consecutive positions in order to screw in all screw bolts or unscrewed, so that there is a considerable gain in time and all operations can continue can be automated with the help of control devices and limit switches (not shown). Finally, the different in this way automated processes with the corresponding likewise automated processes of the whole Unit for tensioning and releasing the screw bolts, for screwing on and unscrewing the main nuts and for Screwing on and unscrewing the auxiliary nuts or for attaching

709845/1050

pulling and releasing the jaws are synchronized.

After unscrewing J: every screw bolt in his unscrewed position hung with the help of a suitable device, which is the locking device can be that / in the same way to energize the Screw bolt is used.

Finally, the entire dismantling of a lid of the container can be automated in this way, whereupon all devices arranged one above the other with the help of a crane or the like, the bolts remaining in place in the locking devices and the lid can then be removed as well as the stack of devices, whereupon the lid is again in place can be attached, these processes taking place quickly, automatically tnS with complete security.

7 C S 8 4 5/1 0 5 0

Claims (3)

Claims 1.j screw tower for screwing in and unscrewing large screw bolts, characterized in that the screw tower in combination a screwing device (1 to 5) with reversible direction of rotation, a gripping device (6) for gripping the head of the screw bolt (23) , which is through the Screw device (1 to 5) is driven and can transmit a torque in the two directions of rotation and an axial force at least in the pulling direction to the screw bolt (23), a device (8, 9; 8a, 15, 18) for guidance and vertical displacement and a compensation device (10; 11) for the weight of the screw bolt (2)). 2. screw tower according to claim 1, characterized in that I net that the compensation device for the weight of the screw bolt (23) by one or more pressure cylinders (10) parallel to the axis of the screwing device (1 to 5) is formed, the or the screwing device and the gripping device with an adjustable force Drive through a stroke that is sufficient to allow this pressure cylinder (10) to act as a device for vertical displacement at the same time to serve. 3. screw tower according to claim 1, characterized in that I net that the compensation device for the weight of the screw bolt (23) by a small pressure cylinder (11) is formed with a small stroke on the spindle (4) of the screwing device (1 to 5) is arranged between this and the gripping device (6) and with these Components rotates, and that the device for axial vertical displacement by a mechanical drive (15 to 18) is formed, which is connected to the drive motor (1) 7C9845 / 1050 ' ^A. ORIGIN A «. ¹ NSPECTED / " the screwing device is synchronized such that the Forward movement per revolution equal to the thread pitch of the screw bolt ^ (23). Screw belt according to one of the preceding claims, characterized marked lean t that the gripping device (6) toiTi grasping the head of the screw bolt (23) has a bowl-shaped part (20) with the lower Connected to the end of the spindle (4) of the screwing device (1 to 5) is and on the one hand at its bottom a diametrical wedge (21) for the rotary drive of a suitable slot (22) having head of the screw bolt (23) and on the other hand has openings in its side walls, which with Balls (24) are filled, which are provided with a groove (24a) provided in the head of the screw bolt (23) and a cooperate outer locking sleeve (25), which is actuated by a coaxial auxiliary pressure cylinder, which rotates with the lower part of the spindle (4). Sight tower according to one of the preceding claims, characterized in that between the lower end of the spindle carrying the gripping device (6) and the middle or upper part of this spindle a coupling connection (7) is arranged which compensates for misalignment. Screw tower according to one of the preceding claims, characterized in that the fixed part the device for guiding and vertical displacement is carried by a carriage that rests on rails (38, 39) is moved over a suitable path in such a way that the axis of the entire device is successively perpendicular guided over the various bolts to be screwed and in these different positions an index device (42) can be locked. 709845/1050 ORIGINAL INSPECTED Screw tower according to claim 7 »characterized in that that the same rails (38, 39) carry several identical carriages, the number of which is less than the number of Screw bolt (23) is, and that the carriages are connected to each other in such a way that they are locked at the same time so are bar and work, that is the number of successive movements required for unscrewing and screwing in a complete bolt ring is required is reduced. 709845/1050