Device for high-altitude assembly of pipeline
Through the sliding connection of the pipeline positioning mechanism and the fixation of the guide positioning rod, the problems of lifting deformation and high-altitude assembly of large-diameter pipelines are solved, and efficient and safe pipeline installation is achieved.
Patent Information
- Application Number
- CN202422084188.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-08-27
AI Technical Summary
Large-diameter pipelines are prone to deformation during lifting, high-altitude assembly is difficult, high construction cost and low efficiency, and safety hazards.
The pipe positioning mechanism is adopted, including positioning components and lifting components. Through the sliding connection between the positioning plate assembly and the lifting adjustment plate, the pipe can be flexibly moved and precisely aligned. The guide positioning rod is used to fix it, replacing traditional lifting lugs and lifting belts, and is suitable for space-constrained environments.
Reduce the hidden dangers of pipeline lifting, improve the quality and efficiency of high-altitude assembly, reduce installation costs, and reduce safety hazards, and is suitable for complex installation environments.
Smart Images

Figure CN223060497U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of pipeline construction, and particularly relates to a device for high-altitude assembly of pipelines. Background Art
[0002] In the existing technology, large-diameter pipelines can be widely used in transporting liquids or gases, such as petroleum, natural gas, water, chemical products, etc., and are applied to dust removal, air supply systems, and multi-functional pipe galleries with the progress of technology. However, due to the influence of installation technology, their application scope and effect are limited. The outer shapes of large-diameter pipelines include various shapes such as circular and square, with circular being the most common. The pipe wall thickness is mostly 6 - 15 mm, and the diameter below 7 m is the most widely used. During installation, the prefabricated pipelines and fittings need to be installed according to the predetermined direction and height, and operations such as hoisting, splicing, and reinforcement are required when necessary. There are problems such as easy deformation during the hoisting process due to the large pipe diameter and thin wall thickness; when laying pipelines at high altitude, there are many cross-constructions and obstacles with civil engineering, steel structures, equipment, etc., the route is long, and the operation site is narrow, and the crane positioning is restricted, resulting in great difficulty in high-altitude assembly; during installation, a large operating space is required, the pipe alignment and welding construction are difficult, and long-term cooperation of hoisting machinery is required, consuming a large number of operating machinery and personnel, resulting in high construction costs and low construction efficiency; if the operation is improper, the assembly alignment deviation is large, affecting the pipeline assembly quality and leading to potential accidents such as pipeline leakage and component deformation. There are technical problems such as easy deformation of the pipeline during hoisting, great difficulty in hoisting and high-altitude splicing installation, high construction costs and low efficiency due to the influence of the installation environment, and improper high-altitude splicing alignment affecting the pipeline assembly quality and generating potential safety hazards. Content of the Utility Model
[0003] To solve the above technical problems, the utility model provides a device for high-altitude assembly of pipelines, which is especially suitable for replacing lifting lugs and lifting belts for pipeline hoisting, reducing the potential deformation hazard during the hoisting process of the pipeline, and can adjust the pipeline according to requirements for positioning during high-altitude assembly of pipeline alignment, enabling rapid and accurate pipeline alignment and splicing. The device occupies a small space and is applicable to various installation environments with limited space and creates construction conditions for welding, solving the drawback of long-term occupation of the crane, thereby improving the high-altitude assembly efficiency of the pipeline, reducing the installation cost, and being convenient for installation and disassembly of the device and reusable.
[0004] The technical solution adopted by the utility model is: a device for high-altitude assembly of pipelines, including a pipeline positioning mechanism. The pipeline positioning mechanism includes a positioning component and a hoisting component. The positioning component includes a positioning plate assembly that can be fixed outside the pipeline. The hoisting component includes a hoisting ear plate for hoisting the pipeline and a hoisting adjustment plate connected to the hoisting ear plate. The positioning plate assembly is slidably connected to the hoisting adjustment plate to drive the pipeline to move.
[0005] Further, the positioning component further includes a plurality of limiting plates that are symmetrically arranged and connected to the positioning plate assembly respectively. Each limiting plate is provided with a sliding hole penetrating therethrough. The hoisting component further includes a plurality of plug-in members respectively arranged on both sides of the hoisting adjusting plate, and each plug-in member is slidably inserted into the corresponding sliding hole.
[0006] Further, when the pipeline is circular, a plurality of limiting plates are respectively arranged at both ends of the positioning plate assembly along the length direction of the pipeline, and each limiting plate is provided with a sliding hole along the circumferential direction of the pipeline.
[0007] Further, the positioning plate assembly includes a plurality of positioning plates that are detachably connected to each other and sleeved outside the pipeline, and the hoisting adjusting plate is slidably connected to any one of the positioning plates.
[0008] Further, the positioning component further includes a plurality of connecting plates, a plurality of fixing components and a plurality of splicing components. Each positioning plate is provided with at least one splicing component. Each splicing component includes two splicing ear plates that are connected to the positioning plate and arranged oppositely to form a splicing groove. Both ends of the connecting plate are respectively embedded in the splicing grooves on adjacent two positioning plates and fixed by the fixing components.
[0009] Further, at least one guiding and positioning rod is further included. Each positioning component further includes at least one guiding and positioning tube connected to the positioning plate assembly. When the number of pipeline positioning mechanisms is multiple and they are spliced end to end, the guiding and positioning tubes arranged on adjacent pipeline positioning mechanisms correspond to each other and are fixed by inserting the guiding and positioning rod.
[0010] The advantages and positive effects of the present utility model are as follows: Due to the adoption of the above technical solution, the hidden danger of deformation of the pipeline during hoisting can be reduced, and the pipeline can be moved and positioned and fixed according to requirements during the high-altitude assembly of the pipeline pair. It has the advantages of simple structure, small occupied space, can improve the high-altitude assembly quality and efficiency of the pipeline, and reduce the installation machinery and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 is a schematic structural diagram of an embodiment of the present utility model
[0012] Figure 2 is a schematic structural diagram of the hoisting component in an embodiment of the present utility model
[0013] Figure 3 is a schematic structural diagram of the positioning component in an embodiment of the present utility model
[0014] Figure 4 is a schematic structural diagram of the connecting plate in an embodiment of the present utility model
[0015] Figure 5 is a usage scenario of the present utility model applied to the temporary fixing of two pipelines
[0016] In the figure:
[0017] 1. positioning plate; 2. lifting ear plate; 3. lifting adjustment plate
[0018] 4. limit plate; 5. splicing ear plate; 6. fixing bolt
[0019] 7. guiding positioning rod; 8. guiding positioning tube; 9. connecting plate
[0020] 31. plug-in component; 32. rolling element; 41. sliding hole Specific embodiments
[0021] The following describes the embodiments of the present utility model in conjunction with the accompanying drawings. The described embodiments are only a part of the embodiments of the utility model, rather than all of the embodiments.
[0022] The following details the embodiments of the present utility model. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar units or units with the same or similar functions throughout.
[0023] The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model. In the description of the present utility model, it should be understood that terms such as "installation", "connection", "fixation", etc. should be understood in a broad sense, which can be direct connection, installation or fixation, or indirect connection, installation or fixation. The present utility model does not limit this.
[0024] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the structure or unit referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.
[0025] Such as Figures 1 to 5As shown in the figure, it is a schematic diagram of an embodiment of a device for high-altitude assembly of pipelines according to the present utility model, which includes a pipeline positioning mechanism. The pipeline positioning mechanism includes a positioning component and a hoisting component. The positioning component includes a positioning plate assembly that can be fixed outside the pipeline. The hoisting component includes a hoisting ear plate 2 for hoisting the pipeline and a hoisting adjustment plate 3 connected to the hoisting ear plate 2. The positioning plate assembly is slidably connected to the hoisting adjustment plate 3 to drive the pipeline to move and be positioned. The present utility model can replace the lifting lug and the lifting belt to assist in the hoisting of the pipeline. Through the mutually slidable positioning plate assembly and the hoisting adjustment plate 3, it can be realized that when the pipeline is hoisted at a high altitude, the pipeline can be moved and positioned according to requirements, making the movement of the pipeline in the air more flexible, convenient and accurate. The device occupies a small space and can be applied to pipeline installation when the space is limited or the environment is complex, improving the quality and installation efficiency of high-altitude assembly of pipelines.
[0026] In this embodiment, the positioning component further includes a plurality of limiting plates 4 that are symmetrically arranged and connected to the positioning plate assembly respectively. Each limiting plate 4 is provided with a sliding hole 41 penetrating therethrough. The hoisting component further includes a plurality of plug-in members 31 respectively arranged on both sides of the hoisting adjustment plate 3. Each plug-in member 31 is slidably inserted into the corresponding sliding hole 41 to drive the pipeline to move.
[0027] The connection mode between the lifting lug plate 2 and the lifting adjustment plate 3 can be fixed by welding. In this embodiment, the surface of the lifting adjustment plate 3 is provided with an opposed positioning hinge for installing the lifting lug plate 2. The opposed positioning hinge and the lifting lug plate 2 are provided with corresponding lifting lug mounting holes, and the detachable connection is realized by inserting the lifting lug mounting bolts. The lifting lug plate 2 can be installed or disassembled according to the use requirements. When it is necessary to lift the pipeline, the lifting lug plate 2 is installed. If it is only used for temporary fixation between multiple pipelines, the lifting lug plate 2 can be disassembled to further reduce the occupied space and save the limited construction space. In this embodiment, each limiting plate 4 is vertically connected to the positioning plate assembly, and each plug-in 31 can move along the length direction of the sliding hole 41 to move the pipeline along the length direction of the sliding hole 41; each plug-in 31 can also move along the direction perpendicular to the length direction of the sliding hole 41 to move the pipeline along the direction perpendicular to the length direction of the sliding hole 41. Moving the pipeline in multiple directions can improve the pipeline positioning accuracy, improve the pipeline assembly quality, and the convenient operation can improve the installation efficiency. In this embodiment, the length of the lifting adjustment plate 3 along the direction perpendicular to the limiting plate 4 is less than the distance between the limiting plates 4 arranged on both sides to enable each plug-in 31 to move along the direction perpendicular to the limiting plate 4; in this embodiment, the width of the sliding hole 41 is less than the thickness of the corresponding lifting adjustment plate 3 to prevent the lifting adjustment plate 3 from slipping out of the sliding hole 41; in other embodiments, the length of the sliding hole 41 can also be designed to be less than the length of the corresponding lifting adjustment plate 3 to prevent the lifting adjustment plate 3 from slipping out of the sliding hole 41; in different embodiments, a clamping member for fixing the plug-in 31 can also be provided on the side of the limiting plate 4 away from each other, that is, on the side of the limiting plate 4 away from the lifting adjustment plate 3. The clamping member can be a clamp that can be fixed outside the plug-in 31, or a pin vertically inserted into the plug-in 31 and clamped to the limiting plate 4. The technology and specific assembly method for fixing the relative position of the positioning plate assembly and the lifting adjustment plate 3 by the clamping member can be flexibly selected based on the general technical knowledge of those skilled in the art. In this embodiment, a plurality of rolling members 32 are rotatably arranged on the lifting adjustment plate 3 to reduce the friction force during the sliding adjustment with the positioning plate assembly. The rolling members 32 can be ball bearings or rotating rods, etc., as long as the friction force during sliding can be reduced, improving the adjustment flexibility and making the moving adjustment more convenient and fast. In this embodiment, each limiting plate 4 is L-shaped and is connected to the surface of the positioning plate assembly to form a U-shaped groove. The U-shaped groove can facilitate the sliding and limiting of the lifting adjustment plate 3 and the plug-in 31, with convenient operation and improved pipeline installation efficiency. Each limiting plate 4 and the positioning plate assembly can be connected by welding or other means, or can be integrally formed.
[0028] The utility model is applicable to the high-altitude assembly of pipelines such as square and circular ones. When the pipeline is a common circular one, the lifting adjustment plate 3 and the positioning plate assembly are adapted arcs. A plurality of limiting plates 4 are respectively arranged at both ends of the positioning plate assembly along the length direction of the pipeline. Each limiting plate 4 is provided with a sliding hole 41 along the circumferential direction of the pipeline, so as to realize that the positioning plate assembly can rotate along the circumferential direction of the pipeline to drive the pipeline to adjust and move along its circumferential direction.
[0029] In this embodiment, each plug-in 31 can also move along the axial direction of the pipeline in the corresponding sliding hole 41 to drive the pipeline to move along its axial direction. When the pipeline is suspended in the air using the lifting ear plate 2, the positioning plate 1 can be moved along the circumferential direction and / or axial direction of the pipeline to drive the pipeline to move along the circumferential direction and / or axial direction, so that when the pipeline is suspended in the air, precise adjustment and movement can be performed to assemble and align, thereby improving the quality and installation efficiency of the pipeline assembly, reducing the operation time of the lifting machinery, and reducing the construction cost.
[0030] In this embodiment, at least one guide positioning rod 7 is also included, and each positioning component also includes at least one guide positioning tube 8 connected to the positioning plate assembly. When the number of pipeline positioning mechanisms is multiple and they are spliced end to end, the guide positioning tubes 8 provided in the adjacent pipeline positioning mechanisms correspond to each other and are fixed by inserting the guide positioning rod 7. In this embodiment, each positioning guide tube 8 is installed on the surface of the limit plate 4. The guide positioning rod 7 is T-shaped for easy operation and can improve the installation efficiency; in other embodiments, a fixing pin can be vertically inserted into the guide positioning rod 7 to prevent the guide positioning rod 7 from slipping out of the guide positioning tube 8. The utility model can be fixed after the pipeline is aligned so that adjacent pipelines can be welded end to end, and can reduce the hidden dangers of component deformation or pipeline leakage caused by alignment offset during welding, and improve the accuracy and construction stability of pipeline high-altitude assembly alignment.
[0031] This embodiment includes the following steps:
[0032] Connect the pipeline to be assembled with at least one pipeline positioning mechanism, and lift the pipeline to the position to be assembled by lifting the ear plate 2;
[0033] When the pipeline suspended in the air needs to be moved for alignment and assembly, the corresponding positioning plate assembly can be slid to drive the pipeline to move, that is, the pipeline is moved along the length direction of the sliding hole 41 or perpendicular to the length direction of the sliding hole 41 for assembly and alignment. When the two pipelines to be assembled have been positioned, the guide positioning tubes 8 arranged on the two pipelines to be assembled correspond to each other and are fixed by inserting the guide positioning rod 7.
[0034] The utility model has a simple structure and can replace lifting ears and lifting belts to assist in pipe lifting. The device occupies a small space and can be suitable for various installation environments such as space is limited or the installation environment is complex, and creates construction conditions for welding. When the pipeline group is assembled at high altitude, the pipeline positioning can be adjusted according to needs, and the installation efficiency is high. The drawback of long-term occupation of the crane can be solved, thereby improving the efficiency of high-altitude pipeline assembly and reducing installation costs. The pipeline can be fixed after positioning to avoid misalignment of the pipeline during welding, improve construction quality, and reduce safety hazards. The device is easy to install and disassemble and can be used in a turnover manner.
[0035] The positioning plate assembly can be designed as a sleeve that matches the shape of the pipeline, such as a round or square shape. In this embodiment, the positioning plate assembly includes a plurality of positioning plates 1 that are detachably connected to each other and are sleeved outside the pipeline. In this embodiment, each positioning plate 1 is connected to at least one stop plate 4 at both ends along the length direction of the pipeline, that is, the hoisting adjustment plate 3 can be slidably connected to any positioning plate 1; in other embodiments, a part of the positioning plates 1 can also be designed to be connected to the stop plate 4 according to the needs for sliding setting of the hoisting adjustment plate 3. The detachable connection method can be quickly installed at any position of the pipeline, especially when the pipeline is long and needs to be installed in the middle of the pipeline to lift the pipeline, there is no need to move the device from the end of the pipeline to the middle, and it can be directly installed in the corresponding position to improve the installation efficiency. The positioning plate 1 design that can be sleeved outside the pipeline and adapted to the shape of the pipeline can reduce the hidden danger of deformation when the pipeline is suspended in the air, and improve the quality of high-altitude assembly of the pipeline. In this embodiment, the positioning plate 1 can be attached to the outside of the pipeline, and the adjustment plate 3 can be attached to the side of the corresponding positioning plate 1 away from the pipeline.
[0036] In this embodiment, the positioning component also includes a plurality of connecting plates 9, a plurality of fixing components and a plurality of splicing components. Each positioning plate 1 is provided with at least one splicing component. Each splicing component includes two splicing ear plates 5 connected to the positioning plate 1 and arranged opposite to each other to form a splicing groove. The two ends of the connecting plate 9 are respectively embedded in the splicing grooves on the two adjacent positioning plates 1 and fixed by the fixing components. In this embodiment, each connecting plate 9 and the splicing ear plate 5 are provided with a matching number of mounting holes. The fixing components include fixing bolts 6 and fixing nuts. The two ends of the connecting plate 9 are respectively embedded in the splicing grooves on the two adjacent positioning plates 1. After the two splicing ear plates 5 and the mounting holes on the ends of the connecting plate 9 embedded between the two splicing ear plates are matched one by one, the fixing bolts 6 are inserted and threadedly connected with the fixing nuts to fix. In this embodiment, the two ends of each limit plate 4 along the length direction are respectively connected to a group of splicing ear plates 5. Each two adjacent positioning plates 1 are connected and fixed by two groups of splicing ear plates 5, two connecting plates 9 and a plurality of fixing components.
[0037] The usage process of this embodiment is as follows:
[0038] The number and specifications of the devices used for high-altitude assembly of pipelines are determined based on the models and specifications of the pipelines to be installed on site and in combination with site conditions. Usually, one pipeline positioning mechanism is used at each end of each pipeline. The on-site lifting equipment can also be used to adaptively adjust the number of pipeline positioning mechanisms according to the length and weight of the pipeline, such as using one or more than two.
[0039] The device of the utility model is detachably connected, and each component is assembled, and can be transported to the installation site in parts and then assembled into a shape, and can be turned over and replaced, and is convenient to transport and store.
[0040] When the pipeline needs to be suspended at a high altitude, multiple connecting plates 9, multiple splicing ear plates 5 and multiple fixing components can be used to connect multiple positioning plates 1 to form a ring that can be sleeved outside the pipeline. The hook of the hoisting machine is passed through the hoisting ear plate 2 to lift the pipeline to the position to be assembled, so that the pipeline is basically in place.
[0041] When the circular pipeline suspended at a high altitude needs to be moved for positioning, the plug-in 31 can be slid along the length direction of the sliding hole 41, that is, the positioning plate assembly is rotated circumferentially along the pipeline to drive the pipeline to be installed to roll finitely along its circumference, so that the pipeline positioning is more accurate; the plug-in 31 can also be pushed in the sliding hole 41 along the axial direction of the pipeline to drive the pipeline to be installed to move finitely along its axis, so as to adjust the distance between adjacent pipelines to be assembled to be suitable for subsequent assembly processes.
[0042] When the pipelines to be assembled are positioned, the guiding positioning tubes 8 on the pipeline positioning mechanisms arranged at the splicing positions of adjacent pipelines correspond to each other. The guiding positioning rods 7 are inserted into the guiding positioning tubes 8 on the two pipelines at the same time to fix the relative positions of the two pipelines to be assembled, so that the two pipeline positioning mechanisms respectively arranged at the head and tail of the two pipelines to be assembled form a whole, better fixing the relative positions of the two conduits to be assembled, and avoiding deviation during subsequent welding and other processes, which affects the pipeline assembly quality.
[0043] After the two pipelines to be assembled are welded and fixed, the hoisting machine can unhook and disassemble the device of the present invention for repeated use.
[0044] The device of the present invention can be used in combination with a hoisting machine for pipeline hoisting. The positioning plate 1 adapted to the shape of the pipeline increases the support area during pipeline hoisting. Compared with only using lifting lugs or tying sling to lift the pipeline, the potential risk of pipeline deformation during hoisting can be reduced; the device of the present invention can be installed at the head and tail splicing positions of the two pipelines to be assembled, which can not only assist in hoisting the pipeline, but also adjust the movement of the pipeline in different directions when the pipeline is suspended at a high altitude. The adjustment operation is convenient and flexible, making the pipeline assembly more accurate, improving the assembly quality and assembly efficiency; after the pipelines to be assembled are positioned, the two pipelines can also be fixed to form a whole, reducing the potential risk of adjacent pipeline offset and dislocation during subsequent pipeline welding; the device of the present invention can be more widely applied to the temporary assembly and fixation of multiple pipelines. One or more connected pipeline positioning mechanisms are sleeved on the heads and tails of the two pipelines for temporary fixation; in actual use, according to the shape of the pipeline, such as square, etc., the positioning plate 1 and the hoisting adjustment plate 3 with a prefabricated adapted shape can be used. By opening a sliding hole 41 adapted to the shape of the pipeline on the limiting plate 4, it can be widely applied to the installation of pipelines with different shapes, realizing the positioning function of adjusting along the length, width and other directions of the pipeline; the device of the present invention is convenient and fast to install and disassemble, and the device structure is simple. After application, the use of large machinery is reduced, the installation operation time is shortened, the operation safety factor is improved, energy is saved and consumption is reduced, and the application range is wide, which is convenient for popularization and use in pipeline construction.
[0045] The embodiments of the present utility model have been described in detail above, but the above content is only the preferred embodiment of the present utility model and cannot be considered as defining the scope of implementation of the present utility model. Any equivalent changes and improvements made within the scope of the application of the present utility model shall still fall within the scope covered by the patent of the present utility model.
Claims
1. A device for high-altitude assembly of pipelines, including a pipeline positioning mechanism, characterized in that: The pipeline positioning mechanism includes a positioning component and a hoisting component. The positioning component includes a positioning plate assembly that can be fixedly arranged outside the pipeline. The hoisting component includes a hoisting ear plate for hoisting the pipeline and a hoisting adjustment plate connected to the hoisting ear plate. The positioning plate assembly is slidably connected to the hoisting adjustment plate to drive the pipeline to move.
2. The device for high-altitude assembly of pipelines according to claim 1, characterized in that: The positioning component further includes a plurality of limiting plates that are symmetrically arranged and connected to the positioning plate assembly respectively. Each limiting plate is provided with a sliding hole penetrating therethrough. The hoisting component further includes a plurality of plug-in members respectively arranged on both sides of the hoisting adjustment plate. Each plug-in member is slidably inserted into the corresponding sliding hole.
3. The device for high-altitude assembly of pipelines according to claim 2, characterized in that: When the pipeline is circular, the plurality of limiting plates are respectively arranged at both ends of the positioning plate assembly along the length direction of the pipeline, and each limiting plate is provided with the sliding hole along the circumferential direction of the pipeline.
4. The device for high-altitude assembly of pipelines according to any one of claims 1-3, characterized in that: The positioning plate assembly includes a plurality of positioning plates that are detachably connected to each other to be sleeved outside the pipeline, and the hoisting adjustment plate is slidably connected to any one of the positioning plates.
5. The device for high-altitude assembly of pipelines according to claim 4, characterized in that: The positioning component further includes a plurality of connecting plates, a plurality of fixing components and a plurality of splicing components. Each positioning plate is provided with at least one splicing component. Each splicing component includes two splicing ear plates that are connected to the positioning plate and arranged oppositely to form a splicing groove. Both ends of the connecting plate are respectively embedded in the splicing grooves on two adjacent positioning plates and fixed by the fixing components.
6. The device for high-altitude assembly of pipelines according to any one of claims 1-3, characterized in that: It further includes at least one guiding and positioning rod. Each positioning component further includes at least one guiding and positioning tube connected to the positioning plate assembly. When the number of the pipeline positioning mechanisms is multiple and they are spliced end to end, the guiding and positioning tubes arranged on adjacent pipeline positioning mechanisms correspond to each other and are fixed by inserting the guiding and positioning rod.