JP2012044097A - Capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor which can ensure a sufficient insulation distance between terminals for external connection while limiting the width of the capacitor, and can contribute to reduction in inductance.SOLUTION: The capacitor comprises a capacitor element 10 having electrode parts 10a, 10a on both end faces, and a pair of electrode plates 20, 30 one of which is connected with one electrode part 10a of the capacitor element 10 while the other is connected with the other electrode part 10a of the capacitor element 10. The pair of electrode plates 20, 30 have main electrode parts 21, 31 and sub-electrode parts 22, 32 extending from the main electrode parts 21, 31 at an angle, respectively, and terminals 23, 33 for external connection are extended from the ends of the sub-electrode parts 22, 32 facing each other, while being faced each other.

Description

  The present invention relates to a capacitor housing and housing a capacitor element and an electrode plate.

  Conventionally, in an electric device such as a power converter, an electrolytic capacitor that is small and can obtain a large capacitance has been used.

  However, since the inductance of an IGBT (insulated gate bipolar transistor) used in an electric device such as a power converter causes a switching loss, the filter capacitor and the snubber capacitor connected to the IGBT have the above-described configuration. Instead of the electrolytic capacitor, a capacitor with a reduced inductance is used.

  As a capacitor with low inductance, a plurality of capacitor elements are connected by a pair of electrode plates, a pair of electrode plates are overlapped via an insulating layer, and stored in a case (for example, a capacitor (for example, For example, the capacitor of Patent Document 1).

JP 2006-245170 A

  However, since the capacitor as shown in Patent Document 1 is easily increased in size, it is necessary to suppress the width of the capacitor in order to incorporate it into an electric device. In order to suppress the width of the capacitor, a plurality of capacitor elements are continuously arranged in the axial direction, and the shape of the capacitor may be elongated in plan view, but the width of the electrode plate is also reduced accordingly. For this reason, there is a possibility that the external connection terminals respectively extended from the two electrode plates are close to each other and a sufficient insulation distance cannot be obtained. Therefore, it is necessary to take another measure for preventing a short circuit such as interposing an insulator between the external connection terminals.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a capacitor that solves the above-described problems and can secure a sufficient insulation distance between external connection terminals while suppressing the width of the capacitor and contributes to a reduction in inductance. .

  In order to solve the above problems, a capacitor of the present invention includes a capacitor element 10 having electrode portions 10a and 10a on both end faces, one connected to one electrode portion 10a of the capacitor element 10, and the other connected to the other of the capacitor element 10. The capacitor includes a pair of electrode plates 20 and 30 connected to the electrode portion 10a, and the pair of electrode plates 20 and 30 has an angle from the main electrode portions 21 and 31 and the main electrode portions 21 and 31, respectively. It has the extended sub-electrode parts 22 and 32, respectively, and it is characterized by extending the external connection terminals 23 and 33 from the opposite ends of the sub-electrode parts 22 and 32 so as to face each other. .

  The main electrode portions 21 and 31 are overlapped with each other, and the sub electrode portions 22 and 32 are overlapped with each other.

  Furthermore, the front ends of the external connection terminals 23 and 33 are bent in a direction approaching each other, and attachment portions 23a and 33a are formed at the front ends.

  According to the capacitor of the present invention, since the external connection terminals are respectively extended from the opposite end portions of the sub electrode portion, the external connection terminals are separated from each other by the same distance as the width of the sub electrode portion. Even when the width of the electrode plate is reduced, that is, when the width of the electrode plate is reduced, a sufficient insulation distance can be secured between the external connection terminals, and an insulator is interposed between the external connection terminals. This eliminates the need to take measures to prevent short circuits.

  In addition, since the main electrode portions and the sub electrode portions of the pair of electrode plates are overlapped, the magnetic fluxes generated in the electrode portions can be canceled with each other, and the inductance can be reduced.

  Furthermore, since the front end portions of the external connection terminals are bent in a direction close to each other, and the attachment portion is formed at the front end portion, the front end portions are separated even if the external connection terminals are separated from each other. It is in the state where they are close to each other, and the mounting property to the electric equipment is improved.

It is a perspective view which shows embodiment of the capacitor | condenser of this invention. It is a disassembled perspective view which shows an electrode plate, insulating paper, and a capacitor | condenser element. It is a disassembled perspective view which shows the assembly state of FIG. 2, and an inner side case. It is a perspective view which shows the attachment state of a terminal board. It is a perspective view which shows the accommodation state to an outer side case.

  Embodiments of a capacitor according to the present invention will be described below in detail with reference to the drawings. As shown in FIGS. 1 and 2, the capacitor 1 according to the present invention includes a plurality of capacitor elements 10..., A first electrode plate 20, a second electrode plate 30, and first and second electrode plates. 20 and 30, an insulating layer 40 interposed between the plurality of capacitor elements 10, first and second electrode plates 20 and 30, and an exterior portion 50 that houses the insulating layer 40.

  The capacitor element 10 is a film capacitor formed by, for example, winding a metallized film in which a metal is vapor-deposited on an insulating film, and metallized electrode portions 10a and 10a formed by thermally spraying metal on both ends in the axial direction. Is formed. Moreover, the shape is a flat columnar shape, and has a flat part with a smooth surface on the side part. In addition, a first lead terminal 60 for connecting to the first electrode plate 20 is connected to one electrode portion 10a, and a second electrode plate 30 is connected to the other electrode portion 10a. A second lead terminal 70 is connected. The capacitor element 10 is not limited to a film capacitor, and various elements can be used.

  Then, as shown in FIG. 2, four capacitor arrays 10 are arranged in the axial direction of the capacitor element 10 so that the electrode portions 10a and 10a face each other, and a capacitor string is formed. Capacitor portions composed of a total of eight capacitor elements 10... Are formed by bringing the flat portions of the elements 10. When the capacitor elements 10 have polarity, the electrode portions 10a and 10a that are adjacent to each other in the direction orthogonal to the axial direction so that the electrodes 10a and 10a facing each other have the same polarity. It arrange | positions so that it may become a reverse polarity.

  The first electrode plate 20 is made of, for example, a metal plate such as copper. As shown in FIG. 2, the main electrode portion 21 having the same area as the capacitor portion in plan view, and one end of the main electrode portion 21. A first electrode extended in a direction opposite to the main electrode portion 21 from the one side end portion of the sub-electrode portion 22. The external connection terminal 23 is provided.

  The main electrode portion 21 is provided with connection holes 21 a for connection to lead terminals connected to the capacitor elements 10. The connection holes 21a are formed only at locations where they are in contact with the first lead terminals 60 connected to one electrode portion (for example, a positive electrode) 10a of the capacitor elements 10. .. avoidance hole 21b for avoiding contact with the second lead terminal 70... At a position facing the second lead terminal 70. Is drilled. Further, the locations where the connection holes 21a are formed are recessed toward the first lead terminals 60. Further, the first external connection terminal 23 has a tip portion bent at a substantially right angle in the plate thickness direction, and a bolt hole (attachment portion) used for connection with an electric device at the tip portion. 23a is drilled.

  The second electrode plate 30 is made of a metal plate such as copper, for example. As shown in FIG. 2, the main electrode portion 31 that is substantially the same area as the capacitor portion in plan view, and one end of the main electrode portion 31. A sub-electrode portion 32 extending substantially perpendicularly from the portion toward the plate thickness direction, and a second electrode extending from the one side end portion of the sub-electrode portion 32 in a direction opposite to the main electrode portion 31. The external connection terminal 33 is substantially the same shape as the first electrode plate 20, but the second external connection terminal 33 is opposite to the first external connection terminal 23. When the first electrode plate 20 and the second electrode plate 30 are overlapped with each other, the main electrode portions 21 and 31 and the sub electrode portions 22 and 32 overlap each other. The first external connection terminal 23 and the second external connection terminal 33 do not overlap each other and sandwich the sub electrode portions 22 and 32 therebetween. It is adapted to direction.

  In addition, the main electrode portion 31 is provided with connection holes 31a for connecting to lead terminals connected to the capacitor elements 10. The connection holes 31a are formed only at locations where they contact the second lead terminals 70 connected to the other electrode portions (for example, negative electrodes) 10a of the capacitor elements 10. .. avoidance hole 31b for avoiding contact with the first lead terminal 60 .., at a position facing the first lead terminal 60 .. Is drilled. In addition, the second external connection terminal 33 has a distal end portion bent at a substantially right angle in the plate thickness direction, and a bolt hole (attachment portion) used for connection with an electric device at the distal end portion. 33a is drilled. As shown in FIG. 2, the distal end portion of the external connection terminal 23 of the first electrode plate 20 and the distal end portion of the external connection terminal 33 of the second electrode portion 30 are directed toward each other. It is bent.

  The insulating layer 40 is, for example, insulating paper and has substantially the same area as the first and second electrode plates 20 and 30. Further, insertion holes 40a, which allow insertion of the first and second lead terminals 60, 70,... Are formed at locations facing the first and second lead terminals 60, 70,. Yes. The insulating layer 40 is not limited to insulating paper, and any insulating material such as an insulating film can be used as long as it has insulating properties. Alternatively, a space (air layer) may be formed between the first and second electrode plates 20 and 30 and disposed so as to be insulated from each other.

  Then, as shown in FIG. 3, the first electrode plate 20 and the second electrode plate 30 are overlaid with the insulating paper 40 interposed therebetween, and the first lead terminals 60. Are respectively inserted into the connection holes 21a of the first electrode plate 20, the first electrode plate 20 and the first lead terminals 60 are connected by solder or the like, and the second lead terminals 70 are connected. Are respectively inserted into the connection holes 31a of the second electrode plate 30, and the second electrode plate 30 and the second lead terminals 70 are connected by solder or the like. As a result, the capacitor elements 10 .. and the first and second electrode plates 20 and 30 are integrated, and the currents flowing in the adjacent capacitor elements 10... Are in opposite directions (arrow A in FIG. 2). Low inductance can be achieved. If there is a risk of internal resonance due to the capacitance and inductance of the capacitor elements 10..., The sizes (areas) of the sub-electrode portions 22 and 32 of the first and second electrode plates 20 and 30 are in advance. It is preferable that the inductance is adjusted so that internal resonance does not occur.

  The integrated capacitor elements 10..., The first and second electrode plates 20 and 30, and the insulating layer 40 are formed on the exterior portion 50 except for the first and second external connection terminals 23 and 33. Stored. As shown in FIGS. 1, 3, and 5, the exterior portion 50 is an inner side that houses the integrated capacitor elements 10, the first and second electrode plates 20 and 30, and the insulating layer 40. The case 51 includes an outer case 52 that houses the inner case 51, and a shrinkable tube 53 that covers the outer case 52.

  The inner case 51 is formed by molding a resin such as PP (polypropylene) or PET (polyethylene terephthalate), for example, and as shown in FIG. 3, a plurality of capacitor elements 10... And the first and second electrode plates 20. , 30 can be stored. Further, an opening 51a is formed on the surface (the upper surface in FIG. 3) facing the first electrode plate 20. The side wall 51b of the inner case 51 has an upper surface of the uppermost first electrode plate 20 when the plurality of capacitor elements 10 and the first and second electrode plates 20 and 30 are accommodated. It is desirable to have a surplus portion located 1 mm or more upward. Accordingly, when the resin is filled in the inner case 51, the resin can be prevented from leaking, and the workability of the filling operation can be improved. Can be provided, and a short circuit can be prevented. In addition, the surplus part should just be 50% or more of the perimeter of the opening part 51a, for example. Further, the inner case 51 is not limited to PP and PET, and PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), or the like may be injection molded.

  The sub-electrode portions 22 and 32 and the external connection terminals 23 and 33 are extended from the opening surface end portion 51 c of the inner case 51 to the outside of the inner case 51, so that the capacitor elements 10. After the electrode plates 20 and 30 are accommodated in the inner case 51, the inner case 51 is filled with resin, and at least the capacitor elements 10... The terminal plate 80 is attached to the second external connection terminals 23 and 33.

  The terminal plate 80 is formed of a resin such as PPS or PBT, for example, and as shown in FIG. 4, a base 81 that contacts the sub-electrode portion 22 of the first electrode plate 20, and the first electrode from the base 81. A leg portion 82 extending in all directions along the sub-electrode portion 22 of the plate 20 is provided. The leg portions 82... Have a length that abuts against the inner side surface of the outer case 52, and are formed in a flat plate shape so that the tip portion thereof faces the inner side surface of the outer case 52. Further, among the plurality of (five in FIG. 4) extending leg portions 82,..., One leg portion 82 has a temperature that shuts off the circuit and prevents ignition when the capacitor 1 abnormally generates heat. A storage case 83 that can store a sensor 90 such as a sensor is provided. The storage case 83 has an opening 83 a that opens in a direction opposite to the inner case 51, and the opening 83 a is provided to protrude outward from the outer case 52. If the sensor 90 is not used, the storage case 83 may not be provided. Further, from the base portion 81, cylindrical terminal blocks 84, 84 interposed between the sub electrode portion 22 of the first electrode plate 20 and the tip ends of the first and second external connection terminals 23, 33 are provided. Two are extended. In the terminal blocks 84 and 84, nuts (not shown) are insert-molded (or inserted into the positions facing the bolt holes 23a and 33a drilled in the tip portions of the first and second external connection terminals 23 and 33 (or Outsert molding).

  After the terminal plate 80 is attached, the inner case 51 is accommodated in the outer case 52 as shown in FIG. The outer case 52 is formed by combining, for example, aluminum plates in a prismatic shape, and has an internal space in which the inner case 51 can be enclosed. An opening 52a is provided on one side surface in the axial direction, and the inner case 51 is accommodated in the outer case 52 from the side where the first and second external connection terminals 23 and 33 are not extended. Then, the leg portions 82 of the terminal plate 80 abut against the inner surface of the outer case 52, and the inner case 51 is positioned in the outer case 52. Further, the inner case 51 can be positioned in the material axis direction by hooking the leg portions 82... To the opening 52 a of the outer case 52. Further, since the legs 82 of the terminal plate 80 abut on the outer case 52, a gap is formed between the inner case 51 and the outer case 52, so that a short circuit with the outer case 52 formed of an aluminum plate is prevented. Can be prevented. Further, the storage case 83 is located in a gap between the inner case 51 and the outer case 52.

  After the inner case 51 is housed in the outer case 52, the outer case 52 is filled with resin, and the auxiliary electrode portions 22 of the first and second electrode plates 20 and 30 are extended outward from the inner case 51. 32 are resin-molded, and a sensor 90 such as a temperature sensor is housed in the housing case 83 as necessary. Further, the outer periphery of the outer case 52 is covered with an insulating shrinkable tube 53 that thermally contracts, and the capacitor 1 is manufactured by heat treatment. At this time, since the opening 83a of the storage case 83 is closed by the shrinkable tube 53, the sensor 90 stored in the storage case 83 is fixed and dust or the like in the storage case 83 is fixed. Intrusion is suppressed.

  As described above, according to the capacitor 1 of the present invention, the main electrode portions 21 and 31 and the sub electrode portions 22 and 32 of the first and second electrode plates 20 and 30 are overlapped with each other via the insulating layer 40. By reversing the directions of the currents flowing through the adjacent capacitor elements 10..., The magnetic fluxes generated at the respective electrode portions can be canceled out and the inductance can be reduced. Further, the first external connection terminal 23 and the second external connection terminal 33 are arranged so as to face each other across the sub electrode parts 22 and 32 from the opposing end parts of the sub electrode parts 22 and 32. Therefore, an insulation distance having the same width as that of the sub-electrode portions 22 and 32 can be provided between the external connection terminals 23 and 33, that is, a sufficient insulation distance can be ensured. There is no need to take another measure for preventing a short circuit, such as interposing an insulator between the connection terminals 23 and 33. Moreover, since the front-end | tip part of the 1st, 2nd external connection terminals 23 and 33 is bent in the direction which adjoins mutually, the connection operation | work to an electric equipment becomes easy and attachment property improves.

  Further, the plurality of capacitor elements 10... Are arranged in the same direction as the direction in which the electrode portions 10a and 10a on both end faces face each other, and the first and second electrode plates 20 and 30 are further arranged. .., The width of the capacitor 1 and the width of the electrode plates 20 and 30 can be suppressed. Further, since the capacitor rows are made close to each other so that the flat portions of the capacitor element 10 are opposed to each other, the storage efficiency of the capacitor elements 10 in the inner case 51 can be improved, and the width of the capacitor 1 Can be further suppressed. Furthermore, since the shape of the capacitor 1 is a prismatic shape, it can be easily incorporated into an electric device.

  In addition, the capacitor element 10... And the first and second electrode plates 20 and 30 are accommodated in the inner case 51 in which the opening 51a is formed in the direction in which the case depth becomes shallow, and at least the capacitor element 10. After the resin molding, the inner case 51 is housed in the outer case 52 having an opening 52a formed on one end surface in the case axial direction, and the resin molding is performed again. Can be suppressed. Therefore, normally, the first and second external connection terminals 23 and 33 are extended from one end surface in the case axial direction, similarly to the electrolytic capacitor in which the external connection terminals extend from one end in the case axial direction. Even when the capacitor of the present invention is used in place of the electrolytic capacitor, no new parts or processing is required for connection to the electric device.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, the first electrode plate and the second electrode plate are overlapped with each other. However, the first electrode plate and the second electrode plate may be opposed to each other with the capacitor element 10 interposed therebetween. Even in this case, if the sub electrode portions 22 and 32 overlap each other, the inductance can be reduced. Further, although a plurality of capacitor elements 10 are used, one capacitor element 10 may be used. In addition, the first and second lead terminals 60 and 70 are used to connect the capacitor element 10 and the first and second electrode plates 20 and 30, but the first and second terminals 60 and 70 are used. Instead, a terminal may be extended from the first and second electrode plates 20 and 30, and the capacitor element 10 and each of the electrode plates 20 and 30 may be connected by this terminal.

  10 .. Capacitor element, 10 a... Electrode part, 20... First electrode plate, 21, 31... Main electrode part, 22, 32... Sub electrode part, 23. 23a, 33a ... bolt holes, 30 ... second electrode plate, 33 ... second external connection terminal

Claims (3)

  Capacitor element (10) having electrode portions (10a) and (10a) on both end faces, one is connected to one electrode part (10a) of capacitor element (10) and the other is the other electrode of capacitor element (10) A capacitor having a pair of electrode plates (20) and (30) connected to the portion (10a), wherein the pair of electrode plates (20) and (30) includes main electrode portions (21) and (31), Sub-electrode portions (22) and (32) extending from the main electrode portions (21) and (31) at an angle, and external connection terminals (from the opposite ends of the sub-electrode portions (22) and (32)) 23) A capacitor characterized by extending (33) opposite to each other.   The capacitor according to claim 1, wherein the main electrode portions (21) (31) are overlapped with each other, and the sub electrode portions (22) (32) are overlapped with each other.   3. The external connection terminal (23) (33) has a distal end portion bent in a direction approaching each other, and an attachment portion (23a) (33a) is formed at the distal end portion. The capacitor described.