Method for manufacturing a switchgear device for an electrical system

Abstract

A method for manufacturing a switchgear of an electrical system, characterized in that it comprises the steps of: providing a first housing shell of the switchgear, made of thermoplastic material and comprising a first coupling edge for coupling with a further housing shell, the first coupling edge having a first coupling surface and a first rib; providing a second housing shell of the switchgear, made of thermoplastic material and comprising a second coupling edge for coupling with the first housing shell, the second coupling edge having a second coupling surface and a second rib; assembling the first and second housing shells and a plurality of operating components of the switchgear, thus obtaining a preliminary assembly of the switchgear; joining the first coupling edge of the first housing shell and the second coupling edge of the second housing shell by means of a vibration welding process, thus forming a joint between the first and second housing shells and obtaining a sealed enclosure for the switchgear.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a switching device for an electrical system (e.g., a load circuit breaker for a medium-voltage electrical system). Background Technology

[0002] As is well known, many switching devices used in secondary power distribution networks (e.g., medium-voltage load circuit breakers) immerse their electrodes in pressurized gas to ensure proper dielectric insulation and efficient arc extinguishing between live parts when the current is interrupted.

[0003] Figure 1 A load circuit breaker 101 for a medium-voltage electrical system is shown, which is a solution available according to the prior art.

[0004] The load circuit breaker 101 includes a housing 104 made of electrically insulating material, which defines an internal volume in which the operating components 102 of the load circuit breaker's electrodes are housed.

[0005] Conveniently, the internal volume of the load circuit breaker 101 is filled with a pressurized insulating gas (e.g., at an absolute pressure of 1.5 bar), such as SF6, dry air, or other gases with low environmental impact.

[0006] The insulating housing 104 includes an upper housing 106 and a lower housing 107, which are joined at suitable coupling edges 108 and 109 by a plurality of bolts or screws 105. Sealing gaskets 110 (O-rings) are arranged between the opposing coupling edges 108 and 109 to ensure proper airtightness.

[0007] Used in manufacturing such as Figure 1 The conventional method for assembling the type of switchgear shown has some key aspects, specifically regarding the assembly of the switchgear housing. Currently, this activity is relatively labor-intensive and time-consuming, and it has a relatively high impact on the overall manufacturing cost of the switchgear.

[0008] As an example, to ensure optimal sealing of the switching device, the coupling edges of the housing must undergo a lengthy surface finishing process (they must be almost completely flat) and the sealing gaskets must be properly positioned and lubricated, which requires manual intervention from experts.

[0009] As another example, arranging several mechanical fasteners to couple the housing shell takes a relatively long time and also requires manual intervention from experts. Summary of the Invention

[0010] The main objective of this invention is to provide a method for manufacturing a switching device that allows for the resolution or mitigation of the technical problems mentioned above.

[0011] More specifically, the object of the present invention is to provide a method for manufacturing a switching device, wherein manufacturing the housing requires a relatively short time.

[0012] Another object of the present invention is to provide a method for manufacturing a switching device, wherein the manufacture of the housing is a relatively easy activity that can be performed even by inexperienced personnel.

[0013] Another object of the present invention is to provide a method for manufacturing a switching device, which is particularly suitable for industrial-scale production at a cost competitive with conventional manufacturing methods of the prior art.

[0014] To achieve these goals and objectives, the present invention provides a switching device.

[0015] In a general definition, the method of the present invention includes the following steps:

[0016] - A first housing housing of the switching device is provided, the first housing housing being made of a thermoplastic material and including a first coupling edge for coupling with another housing housing, the first coupling edge having a first coupling surface and a first rib projecting from the first coupling surface and extending along the first coupling edge. Preferably, the thickness and height of the first ribs of the first coupling edge are different from each other.

[0017] - A second housing housing of the switching device is provided, the second housing housing being made of a thermoplastic material and including a second coupling edge for coupling with the first housing housing, the second coupling edge having a second coupling surface and a second rib projecting from the second coupling surface and extending along the second coupling edge. Preferably, the thickness and height of the second ribs of the second coupling edge are different from each other.

[0018] Assemble the first housing and the second housing, along with multiple operating components of the switching device, to obtain a preliminary assembly of the switching device. The first housing and the second housing are coupled by coupling a first coupling edge of the first housing and a second coupling edge of the second housing. When the first coupling edge of the first housing and the second coupling edge of the second housing are coupled, one or more first ribs of the first coupling edge overlap and contact one or more corresponding second ribs of the second coupling edge. When the first coupling edge of the first housing and the second coupling edge of the second housing are coupled, one or more gaps are formed between the first coupling surface and the second coupling surface and the first and second ribs.

[0019] - By combining the first coupling edge of the first housing shell and the second coupling edge of the second housing shell through a vibration welding process, a joint is formed between the first housing shell and the second housing shell, and a sealed cover for the switching device is obtained.

[0020] Conveniently, during the vibration welding process, the thermoplastic material of the overlapping first and second ribs of the first and second coupling edges at least partially melts and at least partially fills one or more gaps formed between the first and second coupling surfaces and the first and second ribs.

[0021] According to some embodiments of the present invention, the step of assembling the first housing shell, the second housing shell, and the operating component includes:

[0022] - Assemble the first operating component of the switching device onto the first housing housing to form a first sub-assembly of the switching device;

[0023] - The second operating component of the switching device is assembled to the second housing housing to form the second sub-assembly (8) of the switching device.

[0024] - Assemble the first and second sub-components of the switching device and the third operating component to obtain the preliminary components of the switching device.

[0025] According to other embodiments of the present invention, the step of assembling the first housing shell, the second housing shell, and the operating component includes:

[0026] - Assemble the fourth operating component of the switching device into the second housing housing to form the main sub-assembly of the switching device;

[0027] - Assemble the main sub-assembly, the first housing, and the fifth operating component of the switching device to obtain a preliminary assembly of the switching device.

[0028] According to one aspect of the invention, a first housing and a second housing of a switching device, along with operating components, are assembled in the welding chamber of a vibration welding apparatus. The vibration welding apparatus is then activated to join a first coupling edge of the first housing and a second coupling edge of the second housing through a vibration welding process.

[0029] Conveniently, during the vibration welding process, the first coupling edge of the first housing shell and the second coupling edge of the second housing shell move back and forth relative to each other along the main vibration direction. According to one aspect of the invention, the overlapping first and second ribs of the first and second coupling edges, oriented in a direction parallel to the vibration direction when the first and second coupling edges are coupled, have a greater thickness than the overlapping first and second ribs of the first and second coupling edges oriented in a direction transverse to the vibration direction when the first and second coupling edges are coupled.

[0030] According to some embodiments, the method of the present invention includes the following steps: preheating the first housing and the second housing before joining the first coupling edge of the first housing housing and the second coupling edge of the second housing housing by a vibration welding process.

[0031] According to some embodiments, the method of the present invention includes the following steps: after obtaining a sealed outer cover of the switching device, filling the internal volume of the switching device with pressurized dielectric gas.

[0032] Preferably, the switching device is a load circuit breaker for a medium-voltage electrical system. Attached Figure Description

[0033] Other features and advantages of the invention will become apparent from the description of preferred, but not exclusive, embodiments of the switching device according to the invention, of which non-limiting examples are provided in the accompanying drawings, wherein...

[0034] - Figure 1 This is a schematic diagram of a switching device in the prior art;

[0035] - Figures 2 to 15 This is a schematic diagram of different steps in the manufacturing method of the present invention. Detailed Implementation

[0036] Referring to the accompanying drawings, the present invention relates to a method for manufacturing a switching device for an electrical system.

[0037] The method of the present invention is particularly applicable to the manufacture of switching devices having electrodes immersed in a pressurized insulating gas (e.g., SF6 or more environmentally friendly insulating gases such as oxygen, nitrogen, carbon dioxide and / or fluorinated gases).

[0038] Specifically, the method of the present invention is particularly suitable for manufacturing medium-voltage load circuit breakers, and for the sake of brevity, the following description refers specifically to such switching devices. However, the method of the present invention can be successfully used to manufacture different types of switching devices for low-voltage or medium-voltage applications.

[0039] For the purposes of this application, the term "low voltage" refers to operating voltages below 1 kV AC and 1.5 kV DC, while the term "medium voltage" refers to operating voltages above 1 kV AC and 1.5 kV DC up to tens of kV (e.g., up to 72 kV AC and 100 kV DC).

[0040] Switching device 1 preferably has a main longitudinal axis (not shown) and switching device 1 has opposing first side 1A and second side 1B parallel to said main longitudinal axis. Figure 11 ) and the opposing third side 1C and fourth side 1D (perpendicular to the main longitudinal axis of the switching device) Figure 8 ).

[0041] like Figures 8 to 13 As shown, the switching device 1 also has an outer cover 2 and a plurality of operating components 10, which may include electrical components (e.g., electrical contacts, insulators, conductors, etc.), mechanical components (e.g., levers, shafts, connectors, etc.) and electromechanical components (e.g., coils, motors, actuators, etc.).

[0042] Clearly, some operating components 10 (e.g., electrical contacts or sleeves) can protrude outward from the volume defined by the first housing 3 and the second housing 5 (through suitable openings (not shown)). For simplicity, these final components, which are typically arranged at suitable openings in the housing, are not shown in the above figures.

[0043] The manufacturing method of the present invention includes the following steps: providing a first housing shell 3 of an outer cover 2, the outer cover 2 being made of a thermoplastic material.

[0044] Typically, the first housing shell 3 can be implemented according to a known type of scheme (e.g., through a suitable molding process).

[0045] The first shell 3 can have a main body shaped like an open container, such as... Figure 1 , Figure 2 , Figure 6 , Figure 8 , Figure 12 and Figure 14 As shown; or having a subject with a lid-like shape, such as Figure 15 As shown.

[0046] Preferably, the first housing 3 has an elongated shape extending along the main longitudinal direction, which is parallel to the main longitudinal axis of the switching device when the outer cover 2 is formed.

[0047] The first housing 3 has a first coupling edge 4 at which the first housing 3 is intended to be coupled to another housing.

[0048] The first coupling edge 4 preferably forms the periphery of the first housing shell 3 (preferably along a closed line), and it preferably protrudes outward from the body of the first housing shell 3 in a planar shape. However, the shape of the first coupling edge 4 may vary depending on the shape of the first housing shell 3.

[0049] The first coupling edge 4 includes a first coupling surface 40 with another housing shell.

[0050] Preferably, the first coupling surface 40 has a planar profile. However, in principle, the first coupling surface 40 may have different shapes (e.g., corrugated profile) as needed.

[0051] The first coupling edge 4 also includes a plurality of first ribs 41 protruding from the first coupling surface 40.

[0052] The first rib 41 extends parallel (side-by-side) to the first coupling edge 4, thereby following the contour of the first coupling edge 4. Additionally, the first rib 41 and the first coupling edge are spaced apart from each other in the lateral direction (relative to the first coupling edge 4).

[0053] Figure 4 and Figure 7 The transverse cross-sections of the first coupling edge 4 along different sections AA and CC are shown. Figures 2 to 3 and Figures 5 to 6 It can be noted that the first ribs 41 are arranged side by side and are laterally separated from each other.

[0054] Preferably, the first rib 41 has a square or rectangular transverse cross section, such as... Figure 4 and Figure 7 As shown. However, in principle, the first rib 41 can also have different shapes, such as a truncated cone.

[0055] Generally speaking, such as Figure 4 As shown, each first rib 41 has a given height h (the distance between the first coupling surface 40 and the free top surface 411 of each rib) and a given thickness t (the distance between opposite sides of each rib), and the given height h and the given thickness t are preferably different from each other.

[0056] The manufacturing method of the present invention further includes the following step: providing a second housing shell 5 of the outer cover 2.

[0057] The second housing 5 is made of thermoplastic material and can be industrially produced in a known manner, for example, by a suitable molding process.

[0058] The second housing 5 can also be implemented based on known types of solutions, for example, through a suitable molding process.

[0059] The second shell 5 can have a main body shaped like an open container, such as... Figure 1 , Figure 2 , Figure 6 , Figure 8 , Figure 12 , Figure 14 and Figure 15 As shown.

[0060] Preferably, as the first housing shell 3, the second housing shell 5 has an elongated shape extending along the main longitudinal direction, which is parallel to the main longitudinal axis of the switching device when the housing body 2 is formed.

[0061] The second housing 5 has a second coupling edge 6 at which the second housing 5 is intended to be coupled to another housing (the first housing 3).

[0062] In the first housing 3, the second coupling edge 6 preferably forms the periphery of the second housing 5 (preferably along a closed line), and the second coupling edge 6 preferably protrudes outward from the body of the second housing 5 in a planar shape. However, the shape of the second coupling edge 6 may vary depending on the shape of the second housing 5.

[0063] The first coupling edge 4 includes a second coupling surface 60 for coupling with another housing shell (the first housing shell 3).

[0064] Preferably, the second coupling surface 60 has a planar profile. However, in principle, the second coupling surface 60 may have different shapes (e.g., corrugated profiles) as needed.

[0065] The second coupling edge 6 also includes a plurality of second ribs 62 protruding from the second coupling surface 60.

[0066] The second ribs 62 extend parallel (side by side) to the second coupling edge 6, thereby following the contour of the second coupling edge 6, and are spaced apart from each other in the lateral direction (relative to the second coupling edge 6).

[0067] Figure 4 and Figure 7 The transverse cross-sections of the second coupling edge 6 along different sections AA and CC are shown. Figures 2 to 3 and Figures 5 to 6 It can be noted that the second ribs 62 are arranged side by side and are laterally separated from each other.

[0068] Preferably, the second rib 62 has a square or rectangular transverse cross section, such as... Figure 4 and Figure 7 As shown. However, in principle, the second rib 62 can have different shapes, such as a truncated cone.

[0069] Generally speaking, such as Figure 4 As shown, each second rib 62 has a given height h (the distance between the second coupling surface 60 and the free top surface 621 of each rib) and a given thickness t (the distance between opposite sides of each rib), and the given height h and the given thickness t are preferably different from each other.

[0070] The manufacturing method of the present invention then includes the following steps: providing an operating component 10 of a switching device.

[0071] Generally, the operating element 10 of the switching device can be of a known type, and for the sake of simplicity, it will not be described in detail below. In the figures, for simplicity, the operating element 10 of the switching device will be schematically represented by a gray box.

[0072] The manufacturing method of the present invention then includes the following steps: assembling the first housing 3 and the second housing 5 of the switching device and the operating component 10. Figures 2 to 7 Thus, the initial components 99 of the switching device are obtained.

[0073] At this stage of the manufacturing process, the first housing 3 and the second housing 5 are coupled to each other and define a volume that accommodates most of the operating components 10. Figure 3 , Figure 6 ).

[0074] The coupling between the first housing shell 3 and the second housing shell 5 is achieved by coupling the first coupling edge 4 of the first housing shell 3 and the second coupling edge 6 of the second housing shell 5.

[0075] Due to the presence of the first rib 41 and the second rib 62, the first coupling edge 4 and the second coupling edge 6 are coupled to each other when the first coupling surface 40 and the second coupling surface 60 of the first coupling edge 4 and the second coupling edge 6 remain separated from each other.

[0076] Therefore, a gap 9' is formed between the first coupling surface 40 and the second coupling surface 60 of the first coupling edge 4 and the second coupling edge 6 and the ribs 41 and 62 themselves. Figure 4 and Figure 7 ).

[0077] An important aspect of the present invention is that when the first coupling edge 4 and the second coupling edge 6 are coupled to each other, one or more first ribs of the first coupling edge 4 overlap and contact the corresponding one or more second ribs 62 of the second coupling edge 6.

[0078] In practice, according to the present invention, when the first coupling edge 4 and the second coupling edge 6 are coupled to each other, the top surfaces 411, 621 of one or more first ribs 41 and second ribs 62 of the first coupling edge 4 and the second coupling edge 6 overlap and contact each other.

[0079] According to a preferred embodiment of the present invention ( Figure 4 and Figure 7 When the first coupling edge 4 and the second coupling edge 6 are coupled to each other, the plurality of first ribs 41 of the first coupling edge 4 overlap and contact the corresponding second ribs 62 of the second coupling edge 6.

[0080] One or more ribs 41, 62 of the first coupling edge 4 and the second coupling edge 6 overlap to ensure that an enlarged gap 9' is formed between the first coupling surface 40 and the second coupling surface 60 of the first coupling edge 4 and the second coupling edge 6 and the ribs 41, 62 themselves. As described below, the presence of these enlarged gaps 9' is important for improving the bonding process of the coupling edges 4, 6 of the housing shells 3, 5.

[0081] Figure 4 and Figure 7 An embodiment of the invention is shown, wherein the first coupling edge 4 of the first housing 3 includes two central ribs 41a, and the second coupling edge 6 of the second housing 5 includes two lateral ribs 62b located on opposite sides of the coupling edge and at the two central ribs 62b.

[0082] When the first coupling edge 4 and the second coupling edge 6 are coupled, the top surface 621 of the lateral rib 62a of the second coupling edge 6 contacts the first coupling surface 40 of the first coupling edge 4, while the central ribs 41a and 62b of the first coupling edge 4 and the second coupling edge 6 overlap and the top surfaces 411 and 621 of the first coupling edge 4 and the second coupling edge 6 contact each other.

[0083] Conveniently, the height h of the lateral rib 62a of the second coupling edge 6 corresponds to the spacing between the first coupling surface 40 and the second coupling surface 60 of the first coupling edge 4 and the second coupling edge 6, while the heights of the overlapping central ribs 41a and 62b of the first coupling edge 4 and the second coupling edge 6 are complementary, and their sum corresponds to the spacing between the first coupling surface 40 and the second coupling surface 60.

[0084] Those skilled in the art will understand that the first rib 41 and the second rib 62 can be based on... Figure 4 and Figure 7 The different configurations shown are designed for this purpose. However, it is important that one or more ribs 41, 62 of the coupling edges 4, 6 overlap each other and that the top surfaces 411, 621 of the coupling edges 4, 6 contact each other.

[0085] The manufacturing method of the present invention then includes the following steps: after assembling the first housing 3 and the second housing 5 of the switching device and the operating component 10, the first coupling edge 4 of the first housing 3 and the second coupling edge 6 of the second housing 5 are coupled (Figures 8 to 10). Figure 13 ).

[0086] Therefore, a permanent (i.e., no longer separable) joint 19 is formed between the first housing 3 and the second housing 5. Figure 10 and Figure 13 ), and obtained a sealed outer cover 2 for the switching device.

[0087] An important aspect of the present invention is that the connection between the first coupling edge 4 of the first housing shell 3 and the second coupling edge 6 of the second housing shell 5 is obtained by a vibration welding process.

[0088] During this vibration welding process, when the first coupling edge 4 and the second coupling edge 6 are coupled, the thermoplastic material of the first housing shell 3 and the second housing shell 5 at the coupling edges 4 and 6 at least partially melts and at least partially fills the gap 9' formed between the first coupling surface 40 and the second coupling surface 60 and the first rib 41 and the second rib 62.

[0089] The permanent joint formed in this way 19 ( Figure 10 and Figure 13 This ensures a secure mechanical connection between the first housing 3 and the second housing 5, while also ensuring optimal sealing of the internal volume of the switching device against the external environment without the need for gaskets.

[0090] The arrangement of overlapping pairs of ribs 41 and 62, and the subsequent formation of an enlarged gap 9' between the first coupling surface 40 and the second coupling surface 60 and the ribs 41 and 62, greatly facilitates the formation of a more robust joint 19, as a large amount of thermoplastic material can melt and distribute more evenly along the joint segment during the welding process.

[0091] like Figure 10 and Figure 13 As shown, joint 19 may still include some spaces that were not completely filled with the thermoplastic melt after the vibration welding process. However, such spacing has no relevant impact on the robustness and tightness of the mechanical connection between the first housing shell 3 and the second housing shell 5.

[0092] In an actual implementation of the method of the present invention, a vibration welding process is performed by means of a suitable vibration welding process apparatus (not shown), through which the first housing shell 3 and the second housing shell 5 are joined.

[0093] Such vibration welding process apparatus can be of known type, and for the sake of brevity, it will not be described in detail below.

[0094] Typically, the first housing 3 and the second housing 5 of the switching device and the operating component 10 are assembled (as described above) in the welding chamber of the vibration welding device, and then the welding chamber is activated to combine the first housing 3 and the second housing 5 through the vibration welding process.

[0095] During the vibration welding process, the first coupling edge 4 of the first housing shell 3 and the second coupling edge 6 of the second housing shell 5 move back and forth relative to each other along the main vibration direction VD and at a predetermined frequency (e.g., about 100 Hz). This relative movement causes the thermoplastic material to heat up through friction, and causes the first coupling edge 4 and the second coupling edge 6 to melt.

[0096] As mentioned above, the first rib 41 and the second rib 62 of the first coupling edge 4 and the second coupling edge 6 follow the closed-line profile of the first rib 41 and the second rib 62. The first coupling edge 4 and the second coupling edge 6 will include first portions 410, 620 and second portions 410a, 620a, which are oriented in directions parallel and transverse (e.g., perpendicular) to the principal vibration direction VD mentioned above when the first coupling edge 4 and the second coupling edge 6 are coupled (Figure 2). Figure 3 And Figure 5, Figure 6 ).

[0097] According to a preferred embodiment of the present invention, when the first coupling edge 4 and the second connecting edge 6 are coupled ( Figure 4 and Figure 7 Compared to the first portion 410, 620 of the overlapping ribs 41a, 62b oriented in a direction parallel to the vibration direction VD, the second portion 410a, 620a of the overlapping ribs 41a, 62b oriented in a direction transverse to the aforementioned vibration direction VD when the first coupling edge 4 and the second coupling edge 6 are joined, has a greater thickness.

[0098] Preferably, the main vibration direction VD is parallel to the main longitudinal axis of the switching device.

[0099] Therefore, the first rib 41 and the second rib 62 of the first coupling edge 4 and the second coupling edge 6 include longitudinal portions 410 and 620, when the first coupling edge 4 and the second coupling edge 6 are coupled ( Figure 3When the first coupling edge 4 and the second coupling edge 6 are coupled (FIG. 6), the longitudinal portions 410 and 620 are oriented in a direction parallel to the longitudinal first side 1A and the second side 1B of the switching device; and the transverse portions 410a and 620a are oriented in a direction parallel to the transverse third side 1C and the fourth side 1D of the switching device to the vibration direction VD when the first coupling edge 4 and the second coupling edge 6 are coupled (FIG. 6).

[0100] As mentioned above, compared with the transverse portions 410a and 620a of the first rib 41 and the second rib 62, the aforementioned longitudinal portions 410 and 620 of the first rib 41 and the second rib 62 have a smaller thickness. Figure 4 and Figure 7 ).

[0101] The preferred embodiment of the present invention described above ensures that the top surfaces 411, 621 of the overlapping ribs 41, 62 of the coupling edges 4, 6 remain in contact during the vibration welding process, even if the overlapping ribs 410, 620 move relative to each other according to the main direction (main vibration direction VD) transverse to their longitudinal direction (the third side 1C and the fourth side 1D of the switching device). Thus, optimal quality of the welding process is achieved along the entire periphery of the coupled housing shells 3, 5.

[0102] According to some embodiments of the present invention ( Figure 14 The steps of assembling the first housing shell 3, the second housing shell 5, and the operating component 10 include the following sub-steps:

[0103] - Assemble the first operating component 10A of the switching device to the first housing 3 to form the first sub-assembly 7 of the switching device;

[0104] - Assemble the second operating component 10B of the switching device into the second housing 5 to form the second sub-assembly 8 of the switching device;

[0105] - Assemble the first sub-component 7, the second sub-component 8, and the third component 10C of the switching device to obtain the preliminary component 99 of the switching device.

[0106] Assembling the first sub-component 7 and the second sub-component 8 can be achieved using assembly techniques of known types, which will not be elaborated here for the sake of brevity.

[0107] Preferably, the first sub-assembly 7 and the second sub-assembly 8 of the switching device are assembled in corresponding suitable fixtures, which are then positioned in the welding chamber of the vibration welding apparatus. The third operating component 10C of the switching device is then assembled into the first assembly 7 and the second assembly 8 within the welding chamber of the vibration welding apparatus, and the first assembly 7 and the second assembly 8 are activated to engage the first housing housing 3 and the second housing housing 5 and obtain the sealing cover 2.

[0108] These embodiments of the present invention provide fully modular components for switching devices. As an example, the first component 10A and the second component 10B described above may include fixed contacts and bushings of the switching device intended to be fixed to the housing 3, 5, while the third component 10C described above may include internal moving parts (e.g., moving contacts or moving components) of the switching device.

[0109] In some possible variations (not shown) of these embodiments of the invention, each first sub-component 7 and second sub-component 8 can form an electrode of the switching device. Clearly, in this case, the method of the invention can prescribe the formation of several sub-components of the switching device corresponding to the total number of electrodes. The sub-components thus obtained are then joined together by a vibration welding process.

[0110] Other embodiments of the present invention ( Figure 15 The steps of assembling the first housing 3, the second housing 5, and the operating component 10 of the switching device include the following sub-steps:

[0111] - Assemble the fourth operating component 10D of the switching device into the second housing housing 5 to form the main sub-assembly 9 of the switching device;

[0112] - Assemble the main sub-assembly 9 of the switching device, the first housing 3 and the fifth operating component 10E to obtain the preliminary assembly 99 of the switching device.

[0113] The assembly of the main component 9 can be achieved using known assembly techniques, which will not be elaborated here for the sake of simplicity.

[0114] Preferably, the main component 9 of the switching device is assembled in a corresponding fixture, which is then positioned in the welding chamber of the vibration welding device. Then, the first housing 3 and the fifth operating component 10E of the switching device are assembled into the main component 9 within the welding chamber of the vibration welding device. The main component 9 is then activated to engage the first housing 3 and the second housing 5 and obtain a sealed outer cover.

[0115] According to these embodiments of the invention, the first housing 3 serves only as a cover for the main assembly 9 of the switching device, which includes the fixed contacts and sleeves (fourth operating component 10D) and internal moving parts (fifth operating component 10E) of the switching device.

[0116] According to some embodiments of the present invention, the method of the present invention includes the following steps: preheating the first housing shell 3 and the second housing shell 5 by a vibration welding process before joining the first coupling edge 4 of the first housing shell 3 and the second coupling edge 6 of the second housing shell 5.

[0117] Preferably, the first housing shell 3 and the second housing shell 5 are heated at the softening temperature of the thermoplastic material, for example, about 200°C. It can be seen that this scheme allows for further improvements in the welding process of the first housing shell 3 and the second housing shell 5.

[0118] Preferably, after obtaining the preliminary components 99 of the switching device as described above, the first housing 3 and the second housing 5 of the switching device are preheated in the welding chamber of the vibration welding apparatus.

[0119] Preferably, the method of the present invention includes the following steps: after obtaining the sealing outer casing 2 of the switching device as described above, filling the internal volume of the switching device with pressurized dielectric gas ( Figures 8 to 13 ).

[0120] Conveniently, according to known types of solutions, dielectric gas can be injected into the internal volume of the switching device by means of a suitable inlet valve (not shown) arranged in the housing of the switching device.

[0121] The method according to the invention can be varied and modified, but still falls within the scope of the invention. For example, the method of the invention may include the following steps: providing one or more additional housing shells in addition to the first housing shell 3 and the second housing shell 5 described above. These additional housing shells may be constructed in a conventional manner or in a manner similar to the first housing shell and the second housing shell (i.e., the additional housing shells may include coupling edges with suitable coupling ribs), and then joined to the first housing shell 3 and the second housing shell 5 in a conventional manner or by a vibration welding process.

[0122] The method according to the invention offers significant advantages over known prior art devices.

[0123] According to the method of the present invention, the sealing cover 2 of the switching device is obtained by simply welding a suitable thermoplastic housing 3, 5 together. This completely avoids the use of mechanical fasteners and gaskets to join the housings. Additionally, since the housings 3, 5 are welded together, no special surface finishing process is required at the coupling edges of the housings 3, 5.

[0124] Therefore, the method of the present invention allows for relevant time savings in the manufacture of the outer casing 2 of the switching device. Additionally, it can be easily performed even by inexperienced personnel.

[0125] The method of this invention is particularly suitable for industrial implementation. For this purpose, various manufacturing steps can be performed using standard manufacturing processes in a suitable manner. Additionally, compared to prior art solutions where the outer shell is typically made of epoxy resin, using a thermoplastic material for the outer shell 3, 5 allows for a significant reduction in the overall industrial cost of the manufacturing method.

[0126] Therefore, compared with known manufacturing methods in the prior art, the method of the present invention can be carried out industrially at a competitive cost.

Claims

1. A method for manufacturing a switching device (1) for an electrical system, characterized in that, The method includes the following steps: - Provide a first housing (3) of the switching device, the first housing being made of a thermoplastic material and including a first coupling edge (4) for coupling with another housing, the first coupling edge having a first coupling surface (40) and a first rib (41) protruding from the first coupling surface and extending along the first coupling edge (4); - Provide a second housing (5) of the switching device, the second housing being made of a thermoplastic material and including a second coupling edge (6) for coupling with the first housing, the second coupling edge having a second coupling surface (60) and a second rib (62) protruding from the second coupling surface and extending along the second coupling edge (6); - Assemble the first housing shell (3) and the second housing shell (5) and the plurality of operating components (10) of the switching device to obtain a preliminary assembly (99) of the switching device. The first housing shell (3) and the second housing shell (5) are coupled by a first coupling edge (4) of the first housing shell (3) and a second coupling edge (6) of the second housing shell (5). When the first coupling edge (4) of the first housing shell and the second coupling edge (6) of the second housing shell are coupled, one or more first ribs (41a) of the first coupling edge (4) overlap and contact one or more corresponding second ribs (62a) of the second coupling edge (6). One or more pairs of the first rib (41a) and the second rib (62a) overlap such that when the first coupling edge (4) of the first housing shell and the second coupling edge (6) of the second housing shell are coupled, the first coupling surface (40) and the second coupling surface (60) form one or more gaps (9') between the first rib (41) and the second rib (62). - By combining the first coupling edge (4) of the first housing shell (3) and the second coupling edge (6) of the second housing shell (5) through a vibration welding process, a permanent joint (19) is formed between the first housing shell (3) and the second housing shell (5), and a sealing cover (2) for the switching device is obtained. During the vibration welding process, the first coupling edge (4) of the first housing shell (3) and the second coupling edge (6) of the second housing shell (5) move back and forth relative to each other along the main vibration direction (VD). Compared to the first portion (410) of the overlapping first rib (41a) of the first coupling edge (4) oriented in a direction parallel to the vibration direction (VD) and the first portion (620) of the overlapping second rib (62a) of the second coupling edge (6) when the first coupling edge (4) and the second coupling edge (6) are coupled, the second portion (410a) of the overlapping first rib (41a) of the first coupling edge (4) oriented in a direction transverse to the vibration direction (VD) and the second portion (620a) of the second coupling edge (6) have a greater thickness.

2. The method according to claim 1, characterized in that, During the vibration welding process, the thermoplastic material of the first rib (41) of the first coupling edge (4) and the second rib (62) of the second coupling edge (6) is at least partially melted and at least partially filled in one or more gaps (9') formed between the first coupling surface (40) and the second coupling surface (60) and the first rib (41) and the second rib (62).

3. The method according to any one of the preceding claims, characterized in that, The steps of assembling the first housing shell (3), the second housing shell (5), and the operating component (10) include: - The first operating component (10A) of the switching device is assembled to the first housing housing (3) to form the first sub-assembly (7) of the switching device. - The second operating component (10B) of the switching device is assembled to the second housing housing (5) to form the second sub-assembly (8) of the switching device; - Assemble the first sub-component (7) and the second sub-component (8) of the switching device and the third operating component (10C) to obtain the preliminary components (99) of the switching device.

4. The method according to any one of claims 1 to 2, characterized in that, The steps of assembling the first housing shell (3) and the second housing shell (5) include: - Assemble the fourth operating component (10D) of the switching device to the second housing housing (5) to form the main sub-assembly (9) of the switching device; - Assemble the main sub-assembly (9), the first housing (3), and the fifth operating component (10E) of the switching device to obtain the preliminary assembly (99) of the switching device.

5. The method according to claim 1 or 2, characterized in that, The first housing (3) and the second housing (5) of the switching device and the operating component (10) are assembled in the welding chamber of the vibration welding device, which is activated to combine the first coupling edge (4) of the first housing (3) and the second coupling edge (6) of the second housing (5) by a vibration welding process.

6. The method according to claim 1 or 2, characterized in that, The first ribs (41) of the first coupling edge (4) have different thicknesses and heights relative to each other.

7. The method according to claim 1 or 2, characterized in that, The second rib (62) of the second coupling edge (6) has a different thickness and height relative to each other.

8. The method according to claim 1 or 2, characterized in that, The method includes the following steps: preheating the first housing shell (3) and the second housing shell (5) before joining the first coupling edge (4) of the first housing shell (3) and the second coupling edge (6) of the second housing shell (5) by a vibration welding process.

9. The method according to claim 1 or 2, characterized in that, The method includes the following steps: after obtaining the sealing cover (2) of the switching device, filling the internal volume of the switching device with pressurized dielectric gas.

10. The method according to claim 1 or 2, wherein the switching device is a load circuit breaker of a medium-voltage electrical system.

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