Double explosion-proof three-phase capacitor

Abstract

The utility model discloses a double anti -explosion alternating -current three -phase capacitor, including capacitor core group, metal shell and sheet metal upper cover, capacitor core group is fixed in the inner chamber of metal shell, and the edge of sheet metal upper cover is sealed fixed with the top of metal shell, and covers the opening of concave cavity, and the top and bottom of sheet metal upper cover are equipped with external connection wire seat and explosion -proof board respectively, and the bottom of explosion -proof board is equipped with copper foil, and capacitor core group is equipped with the outgoing line, and the outgoing line is electrically connected with copper foil, external connection wire seat and copper foil pass the electric cooperation of easily broken electrode group, and the top periphery of explosion -proof board is fixed with sheet metal upper cover, and the middle part of explosion -proof board is the recess, external connection wire seat sets up in the middle part of sheet metal upper cover and is located above the recess, and capacitor core group includes a plurality of safety film capacitor core. The utility model has two kinds of anti -explosion guarantee, one is capacitor core inside safety film structure anti -explosion, and two is through sheet metal upper cover physical deformation and open easily broken electrode group and cut off the anti -explosion of power, two kinds of anti -explosion are combined together, and are more safe and reliable.

Description

Technical Field

[0001] This utility model relates to a capacitor, and more particularly to a dual explosion-proof AC three-phase capacitor. Background Technology

[0002] Chinese Patent No. CN202123040080.8, published on May 10, 2022, discloses an explosion-proof low-voltage parallel capacitor, comprising a metal casing, a core assembly inside the metal casing, a top cover at the top port of the metal casing, and insulating filler between the core assembly, the metal casing, and the top cover. The surface of the top cover has a grounding terminal and several terminal assembly electrically connected to the core assembly, with an explosion-proof wire connecting the terminal assembly to the core assembly. An explosion-proof reinforcing plate is provided on the bottom surface of the top cover. The explosion-proof function of this structure relies on the internal pressure of the metal casing rising after the capacitor core heats up to a certain extent, causing the top cover to deform and break the explosion-proof wire. However, the process of the capacitor core heating up is actually a process of continuous deterioration of the capacitor, which not only affects the capacitor core but may also affect the entire circuit connected to the capacitor. In addition, if the heat energy inside the metal casing accumulates to a certain level, and if the top cover cannot form a bulging deformation in a normal explosion-proof state due to differences in structural parameters of the top cover or insufficient overall sealing of the metal casing, there is still a risk that the accumulated heat will be released instantly and cause it to explode. It may also affect the electronic components of the surrounding circuit when the heat is too high. Utility Model Content

[0003] The purpose of this invention is to provide a simple, reasonable, safe and reliable double explosion-proof AC three-phase capacitor.

[0004] The purpose of this utility model is achieved as follows: A dual explosion-proof three-phase AC capacitor includes a capacitor core assembly, a metal casing, and a sheet metal cover. The capacitor core assembly is sealed in the inner cavity of the metal casing with epoxy resin. The sheet metal cover is sealed and fixed to the top of the metal casing by its edge and covers the opening of the cavity. The top and bottom of the sheet metal cover are respectively provided with an external terminal block and an explosion-proof plate. The bottom of the explosion-proof plate is provided with copper foil. The capacitor core assembly is provided with leads, which are electrically connected to the copper foil. The external terminal block and the copper foil are electrically connected through an easily disconnectable electrode assembly. The top periphery of the explosion-proof plate is fixed to the sheet metal cover, and the middle part of the explosion-proof plate is a groove. The external terminal block is located in the middle of the sheet metal cover and above the groove. The capacitor core assembly includes a plurality of safety film capacitor cores.

[0005] The objective of this utility model can also be achieved by the following technical measures: As a more specific embodiment, the upper end of the metal shell is provided with a downward flange, the edge of the sheet metal cover is provided with an upward flange, the bottom of the upward flange is provided with a sealant coating, the upward flange and the downward flange overlap, the sealant coating is pressed between the upward flange and the downward flange, and the upward flange and the downward flange are rolled outward together for fixation.

[0006] As a further embodiment, the bottom of the sheet metal cover is provided with a sealing ring and bakelite cardboard in sequence below the external terminal block; the easily disconnectable electrode assembly includes several upper electrodes and lower electrodes, the number of sealing rings is the same as that of the upper electrodes and is sleeved on the upper electrodes, the upper electrodes pass through the external terminal block, the sheet metal cover, the sealing rings and the bakelite cardboard, and the four are riveted together; the upper end of the lower electrode is in contact with the upper electrode for conductive engagement; the lower end of the lower electrode passes through the explosion-proof plate and is electrically connected to the copper foil.

[0007] As a further embodiment, the capacitor core assembly is provided with three safety film capacitor cores, which are arranged axially; the two ends of the capacitor core assembly are respectively provided with an upper insulating cover and a lower insulating cover, and the lead wire passes through the upper insulating cover.

[0008] As a further embodiment, an insulating paper sleeve is also provided in the inner cavity of the metal casing corresponding to the periphery of the capacitor core assembly.

[0009] As a further embodiment, the safety film capacitor core includes a core shaft and two metallized films, wherein the two metallized films are an inner metallized film and an outer metallized film, which are stacked and wound around the core shaft; the inner metallized film includes an inner insulating base film, with a first white edge on one side of the inner insulating base film facing away from the outer insulating base film, and a first electrode gold-plated layer on the other side edge; a first capacitor gold-plated layer is provided on the surface of the inner insulating base film between the first electrode gold-plated layer and the first white edge; and the first electrode gold-plated layer has a first capacitor gold-plated layer along its edge. The outer metallized film has a perforated strip spaced along its length, and a partition strip spaced along the first capacitor gold plating layer. The two ends of the partition strip lead to the first white edge and the perforated strip, respectively. The outer metallized film includes an outer insulating base film. A second white edge is left on the side edge of the outer insulating base film facing the inner insulating base film opposite to the first electrode gold plating layer, and a second electrode gold plating layer is provided on the other side edge. A second capacitor gold plating layer is provided on the surface of the outer insulating base film between the second electrode gold plating layer and the second white edge. A light film is left at the outer end of the outer metallized film, and the light film is tightly wrapped around the outer periphery of the safety film capacitor core.

[0010] As a further option, the three safety film capacitor cores are connected in a delta or star configuration.

[0011] The beneficial effects of this utility model are as follows: (1) This utility model has two explosion protections: one is the explosion protection of the internal safety film structure of the capacitor core, and the other is the explosion protection of the electrode group that can be disconnected by physically deforming the sheet metal cover; the combination of the two explosion protections makes it safer and more reliable.

[0012] (2) The capacitor core of this utility model adopts a safety film structure. The safety film forms a structure of multiple small capacitors connected in parallel. At the same time, the safety film forms a fuse structure between the small capacitors and the electrode surface of the capacitor core. Therefore, when the capacitor has a problem, the local small capacitors fail first, reducing heat generation. Only when the capacitor as a whole thermally runs away can the electrode group be easily disconnected and the power supply cut off, thus playing a double explosion-proof role.

[0013] (3) The bottom of the upper flange of the sheet metal cover of this utility model is provided with a sealant coating, which makes the upper flange and the upper lower flange of the metal shell better sealed. Therefore, when the temperature of the capacitor core rises severely, the air inside the shell expands without leaking, thereby driving the sheet metal cover to deform and pull open the easily disconnectable electrode group, thereby de-energizing the capacitor core group. Attached Figure Description

[0014] Figure 1 This is a cross-sectional structural diagram of an embodiment of the present invention.

[0015] Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle.

[0016] Figure 3 This is a schematic diagram of the metal cover structure of this utility model.

[0017] Figure 4 This is a schematic diagram of the capacitor core structure of this utility model. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: See Figures 1-4 As shown, a dual explosion-proof AC three-phase capacitor includes a capacitor core assembly, a metal casing 1, and a sheet metal cover 5. The capacitor core assembly is sealed in the inner cavity of the metal casing 1 with epoxy resin. The sheet metal cover 5 is sealed and fixed to the top of the metal casing 1 by its edge and covers the opening of the cavity. The top and bottom of the sheet metal cover 5 are respectively provided with an external terminal block 6 and an explosion-proof plate 9. The bottom of the explosion-proof plate 9 is provided with a copper foil 92. The capacitor core assembly is provided with a lead wire 203, which is electrically connected to the copper foil 92. The external terminal block 6 and the copper foil 92 are electrically connected through an easily disconnectable electrode assembly. The top periphery of the explosion-proof plate 9 is fixed to the sheet metal cover 5, and the middle part of the explosion-proof plate 9 is a groove. The external terminal block 6 is located in the middle of the sheet metal cover 5 and above the groove. The capacitor core assembly includes several safety film capacitor cores 2.

[0019] The upper end of the metal shell 1 is provided with a lower flange 11, and the edge of the sheet metal cover 5 is provided with an upper flange 51. The bottom of the upper flange 51 is provided with a sealant coating 52. The upper flange 51 overlaps with the lower flange 11, and the sealant coating 52 is pressed between the upper flange 51 and the lower flange 11. The upper flange 51 and the lower flange 11 are rolled outward together for fixation.

[0020] The bottom of the sheet metal cover 5, corresponding to the area below the external terminal block 6, is provided with a sealing ring 8 and a bakelite cardboard 7 in sequence. The easily disconnectable electrode assembly includes several upper electrodes 61 and lower electrodes 91. The number of sealing rings 8 is the same as that of the upper electrodes 61, and they are fitted over the upper electrodes 61. The upper electrodes 61 pass through the external terminal block 6, the sheet metal cover 5, the sealing rings 8, and the bakelite cardboard 7, and are riveted together. The upper end of the lower electrode 91 makes contact with the upper electrode 61 for conductive engagement; the lower end of the lower electrode 91 passes through the explosion-proof plate 9 and is electrically connected to the copper foil 92. The sealing ring 8 seals the area where the upper electrode 61 passes through the sheet metal cover 5. The combined action of the bakelite cardboard 7 and the external terminal block 6 strengthens the rigidity of the middle part of the sheet metal cover 5. The sheet metal around the external terminal block 6 of the sheet metal cover 5 is relatively thin and easily deformed. The upper end of the lower electrode 91 makes contact with the upper electrode 61. When the sheet metal cover 5 deforms outward, the lower electrode 91 and the upper electrode 61 separate, achieving power disconnection.

[0021] The capacitor core assembly is provided with three safety film capacitor cores 2, which are arranged axially. The two ends of the capacitor core assembly are respectively provided with an upper insulating cover 32 and a lower insulating cover 31, and the lead wire 203 passes through the upper insulating cover 32.

[0022] An insulating paper sleeve 4 is also provided inside the inner cavity of the metal casing 1, corresponding to the outer periphery of the capacitor core assembly.

[0023] The safety film capacitor core 2 includes a core 21 and two metallized films, namely an inner metallized film 22 and an outer metallized film 26. The inner metallized film 22 and the outer metallized film 26 are stacked and wound around the core 21. The inner metallized film 22 includes an inner insulating base film. A first white edge 25 is left on one side of the inner insulating base film facing away from the outer insulating base film, and a first electrode gold-plated layer 23 is provided on the other side. A first capacitor gold-plated layer 24 is provided on the surface of the inner insulating base film between the first electrode gold-plated layer 23 and the first white edge 25. The first electrode gold-plated layer 23 has perforations spaced along its length. The first capacitor gold-plated layer 24 is provided with a partition strip 241 at intervals, and the two ends of the partition strip 241 lead to the first white edge 25 and the hollow strip 231 respectively; the outer metallized film 26 includes an outer insulating base film, and a second white edge 29 is left on the side edge of the outer insulating base film facing the inner insulating base film opposite to the first electrode gold-plated layer 23, and a second electrode gold-plated layer 27 is provided on the other side edge. A second capacitor gold-plated layer 28 is provided on the surface of the outer insulating base film between the second electrode gold-plated layer 27 and the second white edge 29; a light film 261 is left at the outer end of the outer metallized film 26, and the light film 261 is tightly wrapped around the outer periphery of the safety film capacitor core 2. The first capacitor gold-plated layer 24 is provided with a partition strip 241. The gold-plated layers between the partition strips 241 and the second capacitor gold-plated layer 28 together form a parallel structure of multiple small capacitors. Only the smaller gold-plated layers between the hollow strips 231 are connected to the first electrode gold-plated layer 23 and the first capacitor gold-plated layer 24. These smaller gold-plated layers form a fuse structure. When the current exceeds the set value, the smaller gold-plated layers between the hollow strips 231 burn out, and the small capacitors corresponding to the hollow strips 231 are de-energized. This prevents abnormal heating of the capacitor core from the source. When the heat generation of the capacitor core group gets out of control, the easily disconnectable electrode group de-energizes the entire capacitor core group, achieving secondary explosion protection.

[0024] The three safety film capacitor cores 2 are connected in a triangular configuration. Specifically, among the three safety film capacitor cores 2 arranged at the top, middle, and bottom, adjacent safety film capacitor cores 2 are electrically connected through a first conductive sheet 201, and the outer ends of the top and bottom safety film capacitor cores 2 are electrically connected through a second conductive sheet 202. There are six leads 203, arranged in groups of two, each group electrically connected to two first conductive sheets 201 and one second conductive sheet 202 respectively.

[0025] The above describes the preferred embodiments of this utility model, illustrating and describing its basic principles, main features, and advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made without departing from the spirit and scope of this utility model, and all such changes and modifications fall within the scope of protection of this utility model as defined by the appended claims and their equivalents.

Claims

1. A dual explosion-proof AC three-phase capacitor, comprising a capacitor core assembly, a metal shell (1), and a sheet metal cover (5), wherein the capacitor core assembly is sealed in the inner cavity of the metal shell (1) with epoxy resin, the sheet metal cover (5) is sealed and fixed to the top of the metal shell (1) by its edge and covers the opening of the cavity, the top and bottom of the sheet metal cover (5) are respectively provided with an external terminal block (6) and an explosion-proof plate (9), the bottom of the explosion-proof plate (9) is provided with copper foil (92), the capacitor core assembly is provided with lead wires (203), and the lead wires (203) are electrically connected to the copper foil (92); characterized in that: The external connector (6) and the copper foil (92) are electrically connected through an easily disconnectable electrode group. The top periphery of the explosion-proof plate (9) is fixed to the sheet metal cover (5), and the middle part of the explosion-proof plate (9) is a groove. The external connector (6) is located in the middle of the sheet metal cover (5) and above the groove. The capacitor core group includes several safety film capacitor cores (2).

2. The dual explosion-proof AC three-phase capacitor according to claim 1, characterized in that: The upper end of the metal shell (1) is provided with a lower flange (11), and the edge of the sheet metal cover (5) is provided with an upper flange (51). The bottom of the upper flange (51) is provided with a sealant coating (52). The upper flange (51) overlaps with the lower flange (11), and the sealant coating (52) is pressed between the upper flange (51) and the lower flange (11). The upper flange (51) and the lower flange (11) are rolled outward together for fixation.

3. The dual explosion-proof AC three-phase capacitor according to claim 1, characterized in that: The bottom of the sheet metal cover (5) is provided with a sealing ring (8) and bakelite cardboard (7) in sequence below the external terminal block (6); the easily disconnectable electrode group includes several upper electrodes (61) and lower electrodes (91). The number of sealing rings (8) is the same as that of the upper electrodes (61) and they are sleeved on the upper electrodes (61). The upper electrodes (61) pass through the external terminal block (6), the sheet metal cover (5), the sealing rings (8) and the bakelite cardboard (7) and are riveted together; the upper end of the lower electrode (91) is in contact with the upper electrode (61) for conductive contact; the lower end of the lower electrode (91) passes through the explosion-proof plate (9) and is electrically connected to the copper foil (92).

4. The dual explosion-proof AC three-phase capacitor according to claim 1, characterized in that: The capacitor core assembly is provided with three safety film capacitor cores (2), which are arranged axially. The two ends of the capacitor core assembly are respectively provided with an upper insulating cover (32) and a lower insulating cover (31), and the lead wire (203) passes through the upper insulating cover (32).

5. The dual explosion-proof AC three-phase capacitor according to claim 1, characterized in that: An insulating paper sleeve (4) is also provided in the inner cavity of the metal shell (1) corresponding to the outer periphery of the capacitor core assembly.

6. The dual explosion-proof AC three-phase capacitor according to claim 1, characterized in that: The safety film capacitor core (2) includes a core (21) and two metallized films, wherein the two metallized films are an inner metallized film (22) and an outer metallized film (26), and the inner metallized film (22) and the outer metallized film (26) are stacked and wound around the core (21); the inner metallized film (22) includes an inner insulating base film, and a first white edge (25) is left on the edge of the inner insulating base film facing away from the outer insulating base film, and a first electrode gold-plated layer (23) is provided on the other edge. A first capacitor gold-plated layer (24) is provided on the surface of the inner insulating base film between the first electrode gold-plated layer (23) and the first white edge (25). A hollow strip (2) is provided at intervals along the length direction on the first electrode gold-plated layer (23). 31) A partition strip (241) is provided on the first capacitor gold plating layer (24) at intervals. The two ends of the partition strip (241) are respectively connected to the first white edge (25) and the hollow strip (231); the outer metallization film (26) includes an outer insulating base film. A second white edge (29) is left on the side edge of the outer insulating base film facing the inner insulating base film opposite to the first electrode gold plating layer (23). A second electrode gold plating layer (27) is provided on the other side edge. A second capacitor gold plating layer (28) is provided on the surface of the outer insulating base film between the second electrode gold plating layer (27) and the second white edge (29); a light film (261) is left at the outer end of the outer metallization film (26). The light film (261) is tightly wrapped around the outer periphery of the safety film capacitor core (2).

7. The dual explosion-proof AC three-phase capacitor according to claim 4, characterized in that: The three safety film capacitor cores (2) are connected in a delta or star configuration.

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