NL2031843B1

NL2031843B1 - Method and assembly bed for assembling an upright structure

Info

Publication number: NL2031843B1
Application number: NL2031843A
Authority: NL
Inventors: Cornelis Heemskerk Johannes; Arnout Kooij Hendrik
Original assignee: Croonwolter&Dros B V
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2023-11-17

Abstract

Method, assembly bed and grab for assembling an upright structure (2), such as a pantograph disconnector comprising a base (33), at least one upright element (13, 14), such as a ceramic insulator, to be supported by the base (33) and a functional unit (12), such as a pantograph, to be supported by the upright element(s). The assembly bed (20) has a base section (21) for positioning and supporting the base (33), a middle section (22) for supporting and aligning the upright element (2) and a head section (23) for positioning and aligning the functional unit. The base (33) is fixated to the base section (21). In a next step, the upright element (13, 14) is laid on positioners (31, 32) of the middle sec— tion (22) and aligned with the fixated base (33). The up— right element (13, 14) is then fastened to the base (33). The functional unit (12) is positioned on the head section (23) and aligned with the base (33) and the upright element. The functional unit (12) is then mounted to the upright ele— ment (13, 14).

Description

Method and assembly bed for assembling an upright structure

The invention relates to a method and an assembly bed for assembling an upright structure comprising a base, at least one upright element to be supported by the base and a functional unit to be supported by the upright element, such as for example a pantograph disconnector for a high voltage station.

Pantograph disconnectors are used to switch indi- vidual circuits or rails within a high-voltage station or substation. Such pantograph disconnectors are upright struc- tures, usually with a height of 8 meters or more, typically comprising a base, a ceramic insulator on top of the base and a pantograph on top of the insulator. The pantograph is a foldable structure with a releasable contact at its top side and a connection for a conductor at its bottom side.

The structure is foldable between an extended position al- lowing the releasable contact to engage a busbar or rail of a circuit of the high voltage station, and a folded position disconnecting the releasable contact from the busbar or rail. Examples of such a pantograph are disclosed in

GB1318031.

The base of the pantograph is mounted on a sup- port, such as a pour-in foundation or a modular frame carry- ing a number of or disconnectors and/or other functional units.

In a high voltage environment, it is essential that all elements and all structures are accurately aligned and mounted securely. Assembly of a pantograph disconnector or similar upright structures requires the construction worker to perform meticulous work at considerable height while having only limited visibility and not having easy ac- cess to, for instance, fasteners or bolts that must be ten- sioned with a force prescribed by safety regulations. This creates an uncomfortable working environment and long con- struction times.

It is an object of the invention to provide a method and equipment for assembling an upright structure,

such as a pantograph disconnector, in a faster and more ef- ficient manner and in a more comfortable working environ- ment.

The object of the invention is achieved with a method for assembling an upright structure comprising a base, at least one upright element, such as an insulator, to be sup- ported by the base and a functional unit, such as a panto- graph, to be supported by the upright element (s). An assem- bly bed is provided with a base section for positioning and supporting the base, a middle section for supporting and aligning the upright element in a lying position and a head section for positioning and aligning the functional unit. In a first step, the base is fixated to the base section in a pre-defined position. The at least one upright element is then laid on positioners of the middle section and aligned with the fixated base plate. In a next step the upright ele- ment is fastened to the base and the functional unit is po- sitioned on the head section and aligned with the base and the upright element. The functional unit is then mounted to the upright element to complete the upright structure. In a next step, the assembly bed carrying the upright structure is tilted upwardly, e.g., in an upright position. The base plate can then be loosened from the base section and the up- right structure is removed from the assembly bed. Use of the assembly bed makes it possible to assemble the structure in a lying position, preferably in a substantially horizontal position, offering improved view and accessibility for the construction worker. Aligning the base section, the head section and the positioners of the middle section results in quasi-automatic alignment of the structures assembled thereon.

In a specific embodiment, the functional unit is first picked up by a grab carried by a lifting gear and tilted to a substantially horizontal position before it is positioned on the head section of the assembly bed. This enables accu- rately controllable handling of vulnerable structures, such as a pantograph. To secure the functional unit in the grab,

it can be locked in the grab to maintain it in a folded po- sition during tilting.

The base of the upright structure can subsequently mounted on a support, such as a modular frame or a pour-in foundation.

The invention also pertains to the assembly bed provided with a base section for positioning and supporting a base of an upright structure, a middle section for sup- porting and aligning a lying upright element and a head sec- tion for positioning and aligning a functional unit of the upright structure. The base section may for example comprise openings for fixating the base of the upright structure, and an access opening providing access to bolts for connecting the base to at least one upright element of the upright structure.

In a specific embodiment, the positioners of the middle section comprise aligned pairs of parallel rollers for supporting the upright element (s) of the upright struc- ture. The rollers may have parallel rotational axes defining an aligning direction for aligning the upright structure.

The upright element can for example be a ceramic insulator or a pair of ceramic insulators of a pantograph disconnector for a high voltage station. Such insulators typically com- prise a cylindrical stack of circular ceramic fins. Because of the relatively traditional manufacturing methods of such insulators, dimensional deviations can be relatively large so alignment is difficult.

Pantographs typically have two parallel upright insulators: a central insulator column supporting the panto- graph and an auxiliary insulator column encasing a transmis- sion for folding or extending the pantograph. To this end, the middle section of the assembly bed can have two parallel rows of pairs of positioners for supporting two insulator colums lying side by side.

Optionally, the assembly bed may comprise an arm for jointly lifting and/or tilting the base, middle and head sections, so the operator is able to select a desired height and/or angle.

In a specific embodiment, the grab may comprise a

C-shaped frame for gripping around the functional unit and at least one extendable latch for locking the functional unit within the grab during movement of the grab.

Optionally, the grab may comprise a first lifting eye for lifting the grab in a first position with the open side of the C-shaped frame in a lateral orientation, and a second lifting eye for lifting the grab in a second position with the open side of the C-shaped frame in a downward ori- entation.

The invention is further explained with reference to the accompanying drawings showing exemplary embodiments.

Figure 1: shows an example of a high voltage station with pantograph disconnectors;

Figure 2: shows an exemplary embodiment of an assembly bed;

Figure 3: shows positioning of a base of an exemplary pantograph disconnector on the assembly bed;

Figure 4: shows positioning and aligning of a first ceramic insulator;

Figure 5: shows positioning and aligning of a first and second ceramic insulator;

Figure 6: shows a grab with a magnified de- tail;

Figure 7: shows the grab of Figure 6 with a pantograph;

Figure 8: shows the grab of Figure 6 gripping a pantograph with a magnified detail;

Figure 9: shows the grab gripping a pantograph in two positions:

Figure 10: shows positioning and aligning of a pantograph;

Figure 11: shows tilting and lifting of the as- sembled pantograph disconnector.

For background information, Figure 1 shows a typi- cal arrangement in a three-phase high voltage station 1 with pantograph disconnectors 2. Flexible busbars 3, 4, 5 are suspended between rigid end portals 6, 7, and are supported at intermediate points of their lengths by support insula- tors 9. 5 The high voltage station 1 comprises three sets of three pantograph disconnectors 2, mounted in diagonally staggered positions. In the shown embodiment, each panto- graph disconnector 2 comprises a foldable pantograph 12, a central ceramic insulator 13 supporting the pantograph 12, a second ceramic insulator 14 forming part of a transmission for controlling folding and unfolding of the pantograph 12, and a base 15 supporting the pair of ceramic insulators 13, 14. Rotating the second insulator 14 drives the folding mechanism of the pantograph 12. A linkage (not shown) links the second isolators 14 of the three pantograph disconnect- ors 2 of a set, so the pantographs 12 are folded or extended simultaneously. The transmission is not shown in the draw- ings but generally known in the art.

In the shown embodiment, the base 15 is supported by a pour-in foundation 16. Alternatively, the three panto- graph disconnectors 2 of a set can be supported by a modular frame slideable along a set of rails, so the pantograph dis- connectors 2 can be built-up, aligned, tested, transported, positioned and removed jointly in a single unit.

Fach pantograph disconnector 2 connects one of the flexible busbars 3, 4, 5 with one of a set of feeder lines 17, 18, 19 which pass below the busbars 3, 4, 5. The stag- gered disposition of the pantograph disconnectors 2 provides safe voltage clearances between the busbars 3, 4, 5 and the feeder lines 17, 18, 19.

Fach pantograph 12 has a lower terminal connected to an associated feeder line 17, 18, 19 and an upper termi- nal engaging connectors on an associated busbar 3, 4, 5.

The pantograph 12 is a type of four-bar linkage that can fold or extend between a folded position and an ex- tended position, similar to a pantograph connector of an electric train or tram. In the extended position the upper terminal engages the connector of the associated busbar 3,

4, 5. In the folded position (see Figure 1, the middle set of three pantograph disconnectors 2), the upper terminal of the pantograph 12 is disconnected and at safe distance from the connector of the respective busbar 3, 4, 5.

Pantograph disconnectors 2 are usually about 8 me- ters high and need to be accurately mounted and aligned.

This is a difficult and elaborate job, particularly in an outdoor environment. This is even more complicated by the vulnerable construction of the pantographs 12.

Figure 2 shows in perspective view an assembly bed 20, particularly designed for assembling a pantograph dis- connector 2 for a high voltage station as shown in Figure 1.

The assembly bed 20 comprises a base section 21, a middle section 22 and a head section 23. The base section 21 is ar- ranged for positioning and supporting a base of the panto- graph disconnector 2. The middle section 22 is designed for supporting and horizontally aligning the two ceramic insula- tors 13, 14 of the pantograph disconnector 2. The head sec- tion 23 is arranged for positioning and aligning the folda- ble pantograph 12.

The assembly bed 20 further comprises a pedestal 24, and a drive and control unit with hydraulic cylinders (not shown) for lifting and tilting the middle section 22

Jointly with the base and head sections 21, 23 in response to operator control actions.

The base section 21 of the assembly bed 20 com- prises a substantially vertical flange 25 with a central opening 26 and four bolting openings 27. The vertical flange 25 is connected to the middle section 22 by means of a bracket 28.

The middle section 22 comprises a central girder 29 and two crossbeams 30. The central girder 29 extends in a mounting direction M between the base section 21 and the head section 23. The two crossbeams 30 are parallel and sub- stantially perpendicular to the central girder 29. Both crossbeams 30 carry two pairs of positicners comprising cy- lindrical roller supports 31, 32 of a rubber or elastomeric material. The rollers supports 31, 32 have parallel cylin- drical axes extending in the mounting direction M. Both crossbeams 30 have a first pair of the roller supports 31 centered about a vertical center plane of the base section 21. A second pair of the roller supports 32 is placed at a distance from the first pair 31 corresponding to the dis- tance between the longitudinal axes of the two ceramic insu- lators 13, 14 when assembled. The roller supports 31, 32 of one crossbeam 30 are aligned with the roller supports 31, 32 of the other crossbeam 30.

The head section 23 is configured to support a pantograph 12 in a lying position, e.g. horizontally, with its bottom side facing the middle section 22.

Figures 3 —- 10 show consecutive steps of the as- sembly of a pantograph disconnector 2 comprising a base 33, a pair of ceramic insulators 13, 14 and a pantograph 12.

The assembly process starts with bolting the base 33 of the pantograph disconnector 2 to the base section 21 of the assembly bed 20, as shown in Figure 3. The base 33 comprises a central plate 34 with downward extending flanges 35 at opposite sides. The flanges 35 have inwardly bent edges 36. Bolts 37 are used for bolting the base 33 to the base section 21 of the assembly bed 20. The base 33 further comprises two downward inclined flanges 38 extending from opposite sides of the central plate 34. The flanges 38 are provided with a triangular end with a central opening 39.

The central plate 34 of the base 33 is provided with radial slots 40, which are accessible via the central opening 26 in the base section 21 of the assembly bed 20 (see Figure 5).

When bolted, the central plate 34 of the base 33 is aligned with the first row of paired roller supports 31, while the opening 39 in one of the triangular flanges 38 is aligned with the second row of paired roller supports 32.

Next, the two ceramic insulators 13, 14 are suc- cessively laid upon the middle section 22 of the assembly bed 20, as shown in Figures 4 and 5. First, a first ceramic insulator 13 is laid on the first pairs of roller supports 31 aligned with the base section 21. The height of the base section 21 relative to the roller supports 31 is such that the ceramic insulator 13 is automatically aligned with the base 33. The ceramic insulator 13 has a base flange 41 with openings for bolts 42. The bolt openings and bolts 42 are aligned with the radial slots 40 in the central plate 34 of the base 33. Bolts are fitted in the openings 42 and the ra- dial slots 40 and tightened by nuts. Since the nuts are very well accessible via the central opening 26 of the base sec- tion 21, the nuts can easily be tightened with the tighten- ing force prescribed by safety regulations (see Figure 5).

In a next step, the second ceramic insulator 14 is laid on the second row of paired roller supports 32. The second ceramic insulator 14 has a lower end with an axle 45 fitting rotatingly in the opening 39 of the triangular flange 38 of the base 33.

In a next step, a pantograph 12 is positioned on the head section 23 of the assembly bed 20 and aligned with the base 33 and the two ceramic insulators 13, 14. A panto- graph 12 is a vulnerable structure, typically delivered in an upright position on a pallet. Due to the vulnerability and the movable parts of the pantograph 12, the pantograph 12 must be handled with care. To this end, a grab 50 is used carried by a lifting gear 51, as shown in Figures 8 to 11.

The grab 50 has two symmetrically arranged C-shaped claws 52 with an open side 53, a backbone 54 opposite to the open side 53 and two parallel legs 55 extending from the backbone 54 to define a C-shape. The claws 52 are spaced by a first crossbar 56 linking the backbones 54 of the two claws 52, and a second crossbar 57 linking a leg 55 of one claw 52 to an oppositely arranged leg 55 of the other claw 52. Both crossbars 56, 57 are provided with a central hoisting eye 60, 61. Using the hoisting eye 61 of the second crossbar 57 enables lifting of the grab 50 in a first position with the legs 55 of the claws 52 extending horizontally. Using the hoisting eye 60 of the first crossbar 56 enables lifting of the grab 50 in a second position with the legs 55 of the claws 52 extending vertically and the open side 53 being di- rected downward.

When the grab 50 is hoisted in the first position, it can be moved to a pantograph 12 standing in an upright position, e.g., on a pallet (Figure 7). The pantograph 12 comprises a pantograph base 62. The lower legs 55 of the grab are provided with bottom projections 63 for supporting the pantograph base 62, and front and rear projections 64 for locking the pantograph base 62 in a horizontal direc- tion. The two lower legs 55 also comprise two latches 65 which can be moved between a retracted position, allowing placement of the pantograph base 62 on the bottom projec- tions 63, and a locking position, locking the pantograph base 62 by preventing upward movement of the pantograph 12.

The grab 50 can be moved to a pantograph 12 in or- der to grip around the pantograph 12 in such a manner that the pantograph base 62 rests on the bottom projections 63 in between the front and rear projections 64. Then, the latches 65 are moved into their locking position to lock the panto- graph base 62. In that position, the folding mechanism of the pantograph 12 is blocked by the upper legs 55 of the C- shaped claws 52 of the grab 50. This way, the pantograph 12 is protected and immobilized and can safely be tilted.

After gripping the pantograph 12, the hoisting equipment 51 is disconnected from the hoisting eye 61 of the second crossbar 57 and connected to the hoisting eye 60 of the first crossbar 56 (Figure 9). Subsequently lifting the grab 50 will tilt the grab 50 to the second position with the pantograph 12 in a lying position. The grab 50 is then moved to the assembly bed 20 and the pantograph 12 is posi- tioned lying on the head section 23 of the assembly bed 20 with a lower side of the pantograph 12 facing the top ends of the two ceramic insulators 13, 14 (Figure 10). Meanwhile the grab 50 remains in place. The pantograph base 62 is then bolted to the top ends of the ceramic insulators 13, 14.

After mounting the pantograph 12 to the ceramic insula- tors 13, 14, the assembly bed 20 carrying the upright struc- ture 2 is tilted upwardly (Figure 11). Then, the base 33 is disconnected from the base section 21 of the assembly bed 20 and the hoisting equipment 51 is disconnected from the hoisting eye 60 of the first crossbar 56 and connected to the hoisting eye 61 of the second crossbar 57. The panto- graph disconnector 2 is then lifted and moved vertically to the foundation or transportable frame, where the pantograph disconnector 2 is mounted in its final position and prepared for operation.

Claims

CONCLUSIONS

1. Method for assembling a standing structure (2) consisting of a base (33), at least one standing element (13, 14) to be supported by supporting the base (33) and a functional unit (12) by the at least one standing element, wherein a mounting bed (20) is provided with a base section (21) for positioning and supporting the base (33), a center section (22) for supporting and aligning the standing element (2) and a head section (23) for positioning and aligning the functional unit; wherein the base (33) is attached to the base section (21) in a predefined position; in a next step the at least one standing element (13, 14) is placed on positioners (31, 32) of the middle section (22) and aligned with the attached base (33); in a next step the at least one standing element (13, 14) is attached to the base (33); in a next or previous step the functional unit (12) is positioned on the head section (23) and aligned with the base (33) and the at least one standing element; in a next step, the functional unit (12) is mounted on the at least one standing element (13, 14) to complete the standing construction (2).

Method according to claim 1, wherein: in a next step the mounting bed (20) supporting the standing structure (2) is tilted upwards; in a next step, the base (33) is detached from the base part (21) and the standing construction of the mounting bed (20) is removed and placed upright.

A method according to claim 1 or 2, wherein the functional unit is picked up by a gripper (50) carried by a lifting device (51) and tilted to a horizontal position before being placed on the head section (23) of the assembly bed (20) is placed.

Method according to claim 3, wherein the functional unit (12) is locked in the gripper to keep it in folded position during tilting.

Method according to any one of the preceding claims, wherein the base (33) of the standing construction (2) is subsequently mounted on a support, such as a modular frame or a column.

Method according to any one of the preceding claims, wherein the standing construction is a disconnect switch, such as a pantograph disconnect switch (2), of a high-voltage station (1).

7. Assembly bed (20) provided with a base section (21) for positioning and supporting a base (33) of a standing construction, a middle section (22) for supporting and aligning a standing element (13, 14) in a lying position and a head section (23) for positioning and aligning a functional unit (12) of the standing structure.

A mounting bed (20) according to claim 7, wherein the base section (21) includes openings for attaching the base (33) to the standing structure (2), and an access opening (25) providing access to bolts for connecting the base (33) to at least one standing element of the standing structure.

A mounting bed (20) according to claim 7 or 8, wherein the positioners of the center section (22) comprise aligned pairs of parallel rollers (31, 32) for supporting the at least one standing element (13, 14) of the standing construction.

Assembly bed 20 according to claim 7, 8 or 9, comprising a lifting arm for jointly lifting and/or tilting the base, middle and head sections (21, 22, 23).

A gripper (50) for use with the method of claim 3 or 4, wherein the gripper comprises a C-shaped claw (32) for gripping around the functional unit (12) and at least one extendable latch for locking of the functional unit within the gripper during gripper movement.

A gripper (50) according to claim 11, comprising a first lifting eye (61) for lifting the gripper (50) into a first position with the open side (43) of the C-shaped claw in a lateral orientation, and a second lifting eye (60) for lifting the gripper (50) into a second position with the open side of the C-shaped claw (52) in a downward orientation.