JP2012129385A - Capacitor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor device capable of relieving a thermal effect from the outside and suppressing vibration from being transmitted to the outside, without increasing the number of components used.SOLUTION: The capacitor device includes: one or a plurality of capacitor elements; a case body for accommodating the capacitor elements; and resin mold for charging the inside of the case body to cover the surrounding of the capacitor element, and at least a part of the case body is comprised of resin foam.

Description

  The present invention relates to a capacitor device including a capacitor element, and more particularly to a capacitor device mounted on a vehicle such as a hybrid vehicle.

  In a vehicle such as a hybrid vehicle using an internal combustion engine and a motor as power sources, a capacitor device is used as a smoothing element or the like for removing an AC component from a DC voltage. A case mold type capacitor is known as a capacitor device including one or a plurality of capacitor elements. The case mold type capacitor has a structure in which one or a plurality of capacitor elements are accommodated in a case body made of resin and the like, and molded into a resin for moisture prevention or the like.

  In such a case mold type capacitor, in addition to the heat generated by the capacitor element itself during operation, the internal temperature may increase due to the influence of heat from the outside such as electronic components disposed around the case. . In addition, vibration generated in the capacitor element during operation may be transmitted to the outside of the vehicle body or the like through the case body.

  For example, Patent Document 1 is a metallized film capacitor that includes a plurality of capacitor elements and a substantially rectangular parallelepiped outer case containing the capacitor elements, is filled with resin in the outer case, and is installed near the heating element. The metallized film capacitor in which the heat sink, which is a two-layer structure of the metal plate portion and the heat insulating material made of silicon foam, is arranged on the outer surface of the outer case closest to the heating element. It describes that heat generation is dissipated and the influence of heat from the outside is reduced.

  Patent Document 2 discloses a case body fixed to a vehicle body, a capacitor element accommodated in the case body, a pedestal formed from an elastic body and disposed on the case body, and a periphery of the capacitor element. It is described that the transmission of vibration to the vehicle body is suppressed by a capacitor device that includes a filler that fills the case body so as to cover the capacitor element and is supported by the pedestal at a position separated from the case body.

  However, in the technique of Patent Document 1, since a heat sink having a two-layer structure of a metal plate part and a heat insulating material is provided as a separate member, the number of parts increases, which increases the number of attachment steps in manufacturing and increases costs. It becomes a factor. In addition, since the heat sink is bonded to the outer upper surface of the case body as a separate member by adhesion, adhesion, etc., especially in long-term use, it may be exposed from the bonding interface due to mechanical stress such as thermal stress or vibration. Deterioration due to peeling or the like may occur. Further, the transmission of vibration to the outside of the vehicle body or the like is not suppressed.

  Moreover, in the technique of Patent Document 2, the transmission of vibration to the outside of the vehicle main body or the like is suppressed, but the thermal influence from the outside is not sufficiently mitigated.

JP 2008-187206 A JP 2009-177000 A

  The objective of this invention is providing the capacitor | condenser apparatus which can relieve | moderate the thermal influence from the outside and can suppress transmission of the vibration to the outside, without increasing a number of parts.

  The present invention includes one or a plurality of capacitor elements, a case body for housing the capacitor elements, and a resin mold that fills the inside of the case body so as to cover the periphery of the capacitor elements, In this capacitor device, at least a part of the case body is made of foamed resin.

  In the capacitor device, it is preferable that at least a part of the case body is constituted by at least two foamed resin layers, and the foam density of the inner layer is higher than that of the outer layer.

  In the capacitor device, it is preferable that at least the heat generating body side facing the heat generating element outside the case body is made of foamed resin, and the heat radiating side to the outside has a heat radiating structure.

  In the present invention, since at least a part of the case body is made of a foamed resin, the influence of heat from the outside is reduced and the transmission of vibration to the outside is suppressed without increasing the number of parts. It is possible to provide a capacitor device capable of satisfying the requirements.

(A) It is a perspective view which shows the outline of an example of a structure of the capacitor | condenser apparatus which concerns on embodiment of this invention. (B) It is AA sectional drawing in Fig.1 (a). (C) It is an expanded sectional view of the dotted-line part in FIG.1 (b). It is a partial expanded sectional view of the capacitor apparatus in the other example of the capacitor apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the capacitor | condenser apparatus which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  An outline of an example of a capacitor device according to an embodiment of the present invention is shown in FIG. 1A is a perspective view schematically showing an example of the configuration of the capacitor device, FIG. 1B is a cross-sectional view taken along the line AA in FIG. 1A, and FIG. 1C is a dotted line portion in FIG. It is an expanded sectional view. The capacitor device 1 includes one or a plurality of capacitor elements 10, a case body 12 for housing the capacitor elements 10, a resin mold 14 that fills the inside of the case body 12 so as to cover the periphery of the capacitor element 10, Is provided. In the capacitor device 1 according to the present embodiment, at least a part of the case body 12 is made of a foamed resin.

  As shown in FIG. 1B, in the capacitor device 1, one or a plurality of case bodies 12 including a bottom portion 16 and side portions 18 that rise from the periphery of the bottom portion 16 and circulate along the periphery of the bottom portion 16. The capacitor element 10 is accommodated, and a resin mold 14 is formed by filling the case body 12 with resin so as to cover the periphery of the capacitor element 10. A pair of metallicon electrodes 20 are formed on both end faces of the capacitor element 10, and a plurality of capacitor elements 10 are arranged side by side on a pair of metallicon electrodes 20 formed on both end faces of the capacitor element 10 via soldering portions 22 and the like. A pair of bus bars 24, which are external connection terminal portions, are connected to each other, whereby a plurality of capacitor elements 10 are connected in parallel. The resin mold 14 is formed by filling a resin so as to cover the plurality of capacitor elements 10 and the bus bar 24 with one end of the bus bar 24 exposed from the case body 12 as a terminal portion for external connection. . Further, the resin mold 14 is formed so as to fill a space between the plurality of capacitor elements 10 and the inner surface of the bottom portion 16 and the inner surface of the side portion 18. The arrangement of the plurality of capacitor elements 10 shown in FIG. 1 is an example, and the present invention is not limited to this.

  In the capacitor device 1 of FIG. 1, at least a part of the case body 12, and in the example of FIG. 1, the entire case body 12 is made of foamed resin. Is mitigated, and transmission of vibration to the outside is suppressed. By mitigating the influence of heat from the outside, it is possible to prevent the inside of the capacitor device 1 from exceeding the upper limit temperature (for example, 90 to 100 ° C.) of the capacitor element 10. Moreover, since the attachment process in manufacture does not increase without increasing the number of parts, an increase in cost is suppressed. In addition, since the case body 12 does not have a joint surface, the deterioration is not caused by peeling from the interface of the joint due to mechanical stress such as thermal stress or vibration even in long-term use, and the reliability is high. Become.

  In the capacitor device 1 according to the present embodiment, part of the case body 12 may be made of foamed resin, or the entire case body 12 may be made of foamed resin. The case body 12 may be at least partially composed of a non-foamed resin such as PPS (polyphenylene sulfide), PBT (polybutylene terephthalate), PC (polycarbonate), EP (epoxy), or the like. When there is a heating element outside the case body 12, it is preferable that at least the heating element side facing the heating element is made of a foamed resin in order to sufficiently mitigate the thermal effect from the external heating element. In this case, a part of the heating element side facing the heating element may be made of foamed resin, or the entire heating element side may be made of foamed resin. Which part of the case body 12 is made of foamed resin may be appropriately determined according to the installation location of the capacitor device 1 in the vehicle, the installation environment, and the like.

  The foamed resin that constitutes at least a part of the case body 12 is not particularly limited as long as it is a resin in which a gas is dispersed in the resin and is molded into a foamed shape or a porous shape. Examples of the resin that is a raw material for the foamed resin include polyurethane resins, polystyrene resins, polyolefin resins such as polyethylene and polypropylene, phenol resins, polyvinyl chloride resins, urea resins, silicone resins, polyimide resins, and melamine resins. However, in consideration of integral molding with the case body 12, etc., PPS, PBT, PC, EP, etc., which are the same material as the case body 12, are preferable. The resin may be appropriately selected according to required mechanical properties such as strength (hardness), thermal properties such as heat resistance, electrical properties such as dielectric constant, and the like. Moreover, 1 type may be used among these resin, or 2 or more types may be used.

  The foaming density of the foamed resin may be appropriately selected according to required strength, moisture permeability, and the like. For example, when ensuring strength and moisture resistance, the foaming density may be lowered, and when ensuring sound insulation, the foaming density may be increased. The foaming density of the foamed resin can be measured, for example, by a method using a general Archimedes principle.

  The case body 12 at least part of which is made of a foamed resin can be manufactured, for example, by foaming the resin in the whole or part of the case at the time of molding. Therefore, the attachment process in manufacturing does not increase without increasing the number of parts. In addition, by foaming the case itself at the time of molding, it does not have a bonding interface, so it has a structure that does not deteriorate due to peeling from the bonding interface due to thermal stress, mechanical stress, etc., and has high reliability. . There is no restriction | limiting in particular about the foaming method of a foamed resin. Moreover, there is no restriction | limiting in particular about the gas etc. which are used for foaming.

  The shape of the case body 12 is, for example, a substantially rectangular shape, but is not particularly limited.

  Examples of the capacitor element 10 include a film capacitor and a multilayer capacitor in which a pair of metallized films in which a metal vapor deposition electrode is formed on a dielectric film are wound so that the metal vapor deposition electrodes face each other through the dielectric film. It is done.

  The resin mold 14 plays a role of preventing moisture absorption and the like of the capacitor element 10. As resin which comprises the resin mold 14, an epoxy resin, a silicone resin, etc. are mentioned, for example, Among these, an epoxy resin is preferable from points, such as being excellent in moisture resistance and insulation.

  The case body 12 may be further accommodated in a capacitor case made of metal or the like. The capacitor case is formed by, for example, aluminum die casting. The capacitor case may be formed of a metal such as iron or magnesium in addition to aluminum.

  The metallicon electrode 20 is formed, for example, by metal spraying such as Zn / Sn metal.

  The soldering portion 22 is formed by soldering with, for example, Sn—Pb eutectic solder.

  FIG. 2 shows an enlarged cross-sectional view of a part of the capacitor device in another example of the capacitor device according to the embodiment of the present invention (corresponding to FIG. 1C). In the present embodiment, as shown in FIG. 2, the case body 12 is composed of two foamed resin layers 26, that is, an outer layer 26a and an inner layer 26b. Here, the foam density of the inner layer 26b is preferably higher than that of the outer layer 26a. In the foamed resin layer 26 constituting the case body 12, the foam density on the inner side is higher than that on the outer side, so that, for example, strength is ensured and moisture permeability is improved. The foamed resin layer 26 in FIG. 2 has a two-layer structure, but may have a structure of three or more layers.

  Here, in this embodiment, at least a part of the case body 12 may be configured by at least two foamed resins. For example, a part of the case body 12 may be configured by at least two foamed resins, or the entire case body 12 may be configured by at least two foamed resins. A part of the case body 12 may be configured by at least two foamed resins, a part of the case body 12 may be configured by one foamed resin, or a part of the case body 12 may be configured by at least two foamed resins. In addition, a part of the case body 12 may be made of an unfoamed resin.

  When constituted by at least two foamed resins, the resin used as the raw material for the foamed resin may be the same or different. The resin to be used may be appropriately selected according to required mechanical properties such as strength (hardness), thermal properties such as heat resistance, electrical properties such as dielectric constant, and the like.

  Further, the case body 12 is constituted by at least two foamed resin layers 26 including the outer layer 26a and the inner layer 26b as shown in FIG. 2, and the foam density of the inner layer 26b is larger than that of the outer layer 26a. It is good also as a structure made high in steps, and it is good also as a structure made to incline continuously so that it may become a higher foam density from a lower foam density from the outer side to the inner side.

  The foaming density of the foamed resin may be appropriately selected according to required strength, gas permeability, and the like. Which part of the case body 12 is to be formed of the foamed resin in what layer configuration may be appropriately determined according to the installation location of the capacitor device 1 in the vehicle, the installation environment, and the like.

  The case body 12 constituted by at least two foamed resin layers including an outer layer and an inner layer can be manufactured by, for example, a general injection two-color molding method. Moreover, the thing of the structure continuously inclined so that it may become a higher foam density from a lower foam density from the outer side to the inner side can be manufactured by the injection | emission two-color molding method, for example.

  FIG. 3 shows a schematic configuration of another example of the capacitor device according to the embodiment of the present invention. In the capacitor device 1 shown in FIG. 3, one surface of the side portion 18 is a heat dissipation structure 28, and the bottom portion 16 and the remaining side surface 18 of the case body 12 are made of foamed resin. In the case body 12, it is preferable that the heat generating body side facing the heat generating body outside the case body 12 is made of foamed resin, and the heat radiating side to the outside has a heat radiating structure. Thereby, relaxation of the thermal influence from the outside of the case body 12 and heat dissipation from the inside can be performed efficiently.

  Examples of the heat dissipation structure include a structure constituted by a foamed resin having a higher foam density and a two-layer structure.

  As shown in FIG. 3, the case body 12 in which one surface of the side portion 18 is a heat dissipation structure 28 and the bottom portion 16 and the remaining side surface 18 are made of foamed resin is manufactured by, for example, an injection two-color molding method. Can do. In the case body 12, even when the heat dissipation structure 28 and the portion made of foamed resin are formed of different members, the case body 12 can be similarly manufactured by the injection two-color molding method.

  The capacitor device according to the present embodiment is mounted on, for example, a vehicle such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle using an internal combustion engine and a motor as power sources. The capacitor device according to the present embodiment is disposed, for example, in a front portion, a rear portion, or the like of a vehicle or the like, but the arrangement position is not particularly limited.

  DESCRIPTION OF SYMBOLS 1 Capacitor apparatus, 10 Capacitor element, 12 Case body, 14 Resin mold, 16 Bottom part, 18 Side part, 20 Metallicon electrode, 22 Solder part, 24 Bus bar, 26 Foamed resin layer, 26a Outer layer, 26b Inner layer, 28 Heat radiation Construction.

Claims (3)

One or more capacitor elements;
A case body for housing the capacitor element;
A resin mold that fills the inside of the case body so as to cover the periphery of the capacitor element;
With
A capacitor device, wherein at least a part of the case body is made of a foamed resin. The capacitor device according to claim 1,
A capacitor device, wherein at least a part of the case body is composed of at least two foamed resin layers, and the foam density of the inner layer is higher than that of the outer layer. The capacitor device according to claim 1 or 2,
In the case body, at least the heat generating body side facing the heat generating body outside the case body is made of foamed resin, and the heat radiating side to the outside has a heat radiating structure.

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