JP2009289943A - Capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitor capable of suppressing drawbacks such as deterioration in characteristics or lifetime of a capacitive element due to heat generation by a means different from conventional means. <P>SOLUTION: The capacitor 1 has: a plurality of capacitive elements 10a, 10b; and a housing body 12 for housing the plurality of capacitive elements 10a, 10b and attached on a cooler 18. In the housing body 12, a heat radiating member 24 subjected to anodization is set on the capacitive element 10a disposed on a region where the heat radiation performance of the capacitive element should be secured, and the heat radiating member 24 is inserted into the cooler 18 so that part of the heat radiating member may contact a coolant circulating inside the cooler 18. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a capacitor structure.

  Capacitors are basic electrical components used in various industrial equipment, including small and large ones. FIG. 6 is a schematic plan view showing a configuration of a conventional capacitor. FIG. 7 is a schematic cross-sectional view showing an example of the configuration of the capacitor taken along line AA in FIG. In FIG. 6, in order to facilitate the description of the configuration of the capacitor, the container is shown as being transparent. As shown in FIG. 6, the capacitor 4 includes a plurality of capacitor elements 34 a and 34 b and a housing 36 that houses the capacitor elements 34 a and 34 b. The housing 36 is provided with an anode bus bar 38 and a cathode bus bar 40. The anode bus bar 38 is connected to the anode side of the capacitor elements 34a and 34b, and the cathode bus bar 40 is connected to the cathode side of the capacitor elements 34a and 34b. The container 36 is fastened to the cooler 44 by a fastener 42 such as a bolt. The cooler 44 is formed with a cooling portion 46 serving as a refrigerant passage, and a refrigerant inlet and outlet (not shown).

  Normally, when current is passed through the capacitor elements 34a and 34b through the anode bus bar 38 and the cathode bus bar 40, the capacitor elements 34a and 34b generate heat. When a plurality of capacitor elements are arranged in the container 36, generally, a capacitor element 34a arranged near the center of the container 36 (capacitor elements shown by hatching in FIGS. 6 and 7). As it is difficult to dissipate heat to the outside, the temperature tends to be high. And when a capacitor element becomes high temperature, there exists a possibility of causing the malfunction of the characteristic deterioration of a capacitor element, or lifetime reduction. Therefore, high heat resistance or high heat dissipation is required for the capacitor element 34a disposed in a region where the temperature tends to be high.

  For example, in Patent Document 1, a polyethylene terephthalate film or a polyethylene naphthalate film (a film having high heat resistance) is provided in a region that tends to be high in temperature (that is, a region where heat resistance or heat dissipation of the capacitor element needs to be ensured). A capacitor has been proposed in which a capacitor element using a polypropylene film (a film having low heat resistance) is disposed in a region other than the region where the used capacitor element is disposed and the temperature tends to be high. According to the capacitor of Patent Document 1, since the heat resistance of the capacitor element arranged in a region that tends to be high in temperature can be improved, it is possible to suppress problems such as deterioration in characteristics or lifetime of the capacitor element.

Japanese Patent Laid-Open No. 2006-269652 Japanese Patent Laid-Open No. 5-326344 JP-A-11-204378

  An object of the present invention is to provide a capacitor capable of suppressing problems such as deterioration of characteristics or lifetime of capacitor elements due to heat generation by means different from conventional ones.

  The present invention is a capacitor having a plurality of capacitor elements and a container that accommodates the plurality of capacitor elements and is attached to a cooler, and ensuring heat dissipation of the capacitor elements in the container. An alumite-treated heat dissipating member is installed in the capacitor element disposed in the required area, and the heat dissipating member is inserted into the cooler so that a part of the heat dissipating member is in contact with the refrigerant flowing in the cooler. Is done.

  Further, in the capacitor, it is preferable that the plurality of capacitor elements are of a wound type.

  In the capacitor, the heat dissipating member is installed in a core portion of a capacitor element disposed in the region, and the heat dissipating member is disposed in the cooler so that a part of the heat dissipating member is in contact with the refrigerant flowing in the cooler. It is preferable that it is inserted into.

  Moreover, in the capacitor, it is preferable that a threaded portion is provided at a position of the heat dissipating member inserted into the cooler.

  According to the present invention, it is possible to suppress problems such as deterioration of characteristics or lifetime of capacitor elements due to heat generation.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic plan view showing an example of the configuration of a capacitor according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the configuration of the capacitor taken along line AA in FIG. In FIG. 1, the container is shown as being transparent in order to facilitate description of the configuration of the capacitor. As shown in FIG. 1, the capacitor 1 includes a plurality of capacitor elements 10 a and 10 b and a housing 12 that houses the capacitor elements 10 a and 10 b. As shown in FIG. 2, the container 12 is provided with an anode bus bar 14 and a cathode bus bar 16. Anode bus bar 14 is connected to the anode side of capacitor elements 10a and 10b, and cathode bus bar 16 is connected to the cathode side of capacitor elements 10a and 10b.

  The container 12 is attached to the cooler 18. Specifically, as shown in FIG. 1, the container 12 is fastened to the cooler 18 by a fastener 20 such as a bolt. Examples of the material of the container 12 include resin materials such as polyphenylene sulfide, polybutylene terephthalate, and polyether ether ketone.

  The cooler 18 to which the container 12 is attached will be described. As shown in FIG. 2, the cooler 18 includes a cooling inlet (not shown), a cooling outlet (not shown), and a cooling unit 22 serving as a passage through which the refrigerant flows. In the cooler 18, the refrigerant introduced from the cooling inlet flows through the cooling unit 22 (for example, in the direction of the arrow shown in FIG. 1), and the refrigerant is discharged from the cooling outlet. As the cooler 18 in the present embodiment, a cooler for an electronic device such as an inverter circuit in which a capacitor is used can be used for cooling the capacitor element.

  Among the capacitor elements 10a and 10b arranged in the container 12, the capacitor element 10a (capacitor element shown by hatching in FIGS. 1 and 2) arranged in a region where it is necessary to ensure heat dissipation of the capacitor element. Is provided with a heat dissipating member 24 that has been subjected to alumite treatment. Here, the region where it is necessary to ensure the heat dissipation of the capacitor element is a region where the temperature of the capacitor element becomes so high that there is a risk of malfunction of the capacitor element because it is difficult to dissipate the capacitor element. In general, when a plurality of capacitor elements are arranged in the container 12, the capacitor elements 10a (capacitor elements shown by hatching in FIGS. 1 and 2) arranged near the center of the container 12 are more external. Because it is difficult to dissipate heat, the temperature tends to be high. Therefore, it is necessary to ensure heat dissipation of the capacitor element 10a disposed near the center of the container 12. However, the capacitor element 10a disposed in the region where it is necessary to ensure the heat dissipation of the capacitor element is not limited to the capacitor element disposed in the vicinity of the center of the container 12, and the usage environment of the capacitor, etc. It varies depending on the situation. For example, if there is a high heat source near any side surface of the container 12, it is difficult to dissipate heat to the outside of the capacitor element disposed near the side surface of the container 12. Therefore, it is necessary to ensure the heat dissipation of the capacitor element disposed near the side surface of the container 12 near the high heat source.

  As shown in FIG. 1, the heat radiating member 24 is installed in the capacitor element 10 a, and the cooling unit 22 of the cooler 18 is in contact with the refrigerant flowing through the cooling unit 22 of the cooler 18 while a part of the heat radiating member 24 is in contact. It is inserted in. In order to insert the heat radiating member 24 into the cooling unit 22 of the cooler 18, a through hole through which the heat radiating member 24 passes is formed in the partition wall 18 a (and the anode bus bar 14) of the cooler 18.

The heat radiating member 24 is for releasing the heat of the capacitor element 10a to the cooler 18 side, and the heat radiating member 24 is subjected to alumite treatment. By performing the alumite treatment, heat dissipation and insulation can be improved. The alumite treatment may be performed on the entire heat radiating member 24 or may be performed on a part thereof. When alumite treatment is performed on a part of the heat radiating member 24, at least a portion of the heat radiating member 24 that needs to be provided with an insulating property may be alumite treated. For example, the part is inserted into the cooling unit 22 of the cooler 18. This is the location of the heat dissipation member 24 (d shown in FIG. 2). The heat radiating member 24 is formed by forming an aluminum layer on the surface of an aluminum material or a metal core material such as copper that can be anodized. Further, the heat radiating member 24 may or may not have a heat pipe structure. The alumite treatment to the heat radiating member 24 is, for example, a treatment method in which an aluminum material is immersed in sulfuric acid, phosphoric acid, an oxalic acid aqueous solution, or the like, and electrolyzed (for example, current density 10 mA / cm ² ). By subjecting the aluminum material to an alumite treatment, an alumite film such as Al ₂ O ₃ is formed on the aluminum material, so that the location where the alumite treatment is performed is improved in electrical insulation and heat dissipation.

  When current is passed through the capacitor elements 10a and 10b, the capacitor elements 10a and 10b generate heat. As described above, the temperature rise of the capacitor element 10a disposed in a region where it is necessary to ensure heat dissipation, such as the capacitor element disposed near the center of the container 12, is significant. In the present embodiment, a heat radiating member 24 is installed in the capacitor element 10a arranged in a region where it is necessary to ensure heat dissipation, and a part of the heat radiating member 24 is placed in the cooler 18 (substantially cooling). Is inserted into the cooler 18 so as to be in contact with the refrigerant flowing through the portion 22). Therefore, the heat generated in the capacitor element 10a is transmitted to the refrigerant flowing through the cooling unit 22 via the heat radiating member 24, and heat is released from the refrigerant to the outside. As a result, the heat dissipation characteristics of the capacitor element 10a disposed in the region where it is necessary to ensure heat dissipation can be improved, and the occurrence of defects in the capacitor element can be suppressed. Moreover, in this embodiment, since the heat radiating member 24 is anodized, the heat radiating member 24 has high insulation and heat radiating properties, and the heat of the capacitor element 10a can be efficiently moved to the cooler 18 side. it can. In addition, since a heat resistant film etc. are not used, it is also possible to suppress the cost increase of a capacitor.

  As described above, the heat of the capacitor element 10a disposed in the region where heat dissipation is required is transmitted to the cooler 18 side via the heat dissipation member 24, so that it is not necessary to ensure heat dissipation characteristics. It is possible to suppress thermal diffusion to the capacitor element 10b side disposed in the region. Therefore, deterioration of the capacitor element 10b due to heat from the capacitor element 10a can be suppressed.

  Capacitor elements 10a and 10b have a structure in which electrodes (anode and cathode) are arranged on both sides of a dielectric layer (dielectric film) and are laminated or wound. Capacitor elements 10a and 10b have electrodes (anode and cathode) disposed on both sides of the dielectric layer in terms of easy manufacturing, a structure that easily transfers heat of capacitor element 10a to heat radiating member 24, and the like. It is preferably a wound type in which they are wound.

  The installation location of the heat dissipation member 24 in the capacitor element 10a is not particularly limited. However, since it is difficult to release heat toward the core portion 26 of the capacitor element 10a (that is, the center portion of the capacitor element), the heat dissipating member 24 has a core of the capacitor element 10a as shown in FIG. It is preferable that the heat radiating member 24 is inserted into the cooler 18 so that a part of the heat radiating member 24 is in contact with the refrigerant flowing through the cooler 22 of the cooler 18. Thereby, the heat of the core part 26 of the capacitor | condenser element 10a from which temperature becomes high can be efficiently discharge | released to a refrigerant | coolant. As a result, the heat dissipation characteristics of the capacitor element 10a can be improved. However, the heat radiating member 24 may be a place other than the core part 26 of the capacitor element 10a. For example, the heat radiating member 24 may be installed on an end surface, an outer peripheral surface, or the like of the capacitor element 10a.

  As an example of installing the heat radiating member 24 on the core part 26 of the capacitor element 10a, for example, a method in which electrode foils (anode foil and cathode foil) are arranged on both sides of a dielectric film is wound around the heat radiating member 24. That is, by using the heat radiating member 24 as a core, the heat radiating member 24 can be disposed on the core portion 26 of the capacitor element 10a.

  When the capacitor element 10 a is fixed to the cooler 18, a nut is usually inserted into the core part 26 of the capacitor element 10 a and a threaded part is formed in the partition wall 18 a of the cooler 18. Then, screws are fixed by inserting a fastener such as a bolt through the threaded portion of the partition wall 18 a of the cooler 18 and the nut of the core portion 26. In such a configuration, when the screw is fixed, a mechanical force acts on the capacitor element 10a, and the capacitor element 10a may be damaged. FIG. 3 is a schematic cross-sectional view showing another example of the configuration of the capacitor according to the embodiment of the present invention. FIG. 4 is a schematic view showing a portion of the heat radiating member inserted into the cooler shown in FIG. In the capacitor 2 shown in FIG. 3, the same reference numerals are given to the same configurations as those of the capacitor 1 shown in FIG. As shown in FIG. 3, the capacitor 2 according to this embodiment includes a winding of a capacitor element 10 a disposed in a region where heat dissipation is required, such as a capacitor element disposed near the center of the container 12. The core portion 26 is provided with a heat dissipating member 24 that has been subjected to alumite treatment, and a portion of the heat dissipating member 24 is in contact with the refrigerant flowing in the cooler 18 (substantially the cooling portion 22). It is inserted in. Further, as shown in FIG. 4, a threaded portion 28 is provided at a position of the heat radiating member 24 inserted into the cooler 18, and screwed with the threaded portion 30 provided in the partition wall 18 a of the cooler 18. Is done. The threaded portion 30 provided in the partition wall 18 a is formed in a through-hole of the partition wall 18 a provided to allow the heat radiation member 24 to be inserted into the cooling unit 22 of the cooler 18. With the above-described configuration, it is possible to prevent mechanical force from acting on the capacitor element 10a itself at the time of screw fixation, and thus it is possible to prevent damage to the capacitor element 10a. Moreover, in this embodiment, in order to ensure insulation with the heat radiating member 24, the cooler 18, and a refrigerant | coolant, it is preferable that the threading part 28 formed in the heat radiating member 24 is also anodized.

  In the present embodiment, it is preferable to provide a sealing material on the threaded portion 28 formed on the heat radiating member 24. With the above configuration, airtightness between the heat radiating member 24 and the cooler 18 (through hole of the cooler 18) can be ensured, so that the refrigerant in the cooler 18 can be prevented from flowing out. . The sealing material has a certain degree of elasticity in order to improve the airtightness between the heat radiating member 24 and the cooler 18 (through hole of the cooler 18). For example, a seal tape (adhesive tape), a gasket or the like is used. Can be mentioned. For example, by winding a sealing tape (adhesive tape) around the threaded portion 28 formed on the heat radiating member 24, the airtightness between the heat radiating member 24 and the cooler 18 (through hole of the cooler 18) can be easily increased. Is possible.

  FIG. 5 is a schematic cross-sectional view showing another example of the configuration of the capacitor according to the embodiment of the present invention. In the capacitor 3 shown in FIG. 5, the same reference numerals are given to the same configurations as those of the capacitor 1 shown in FIG. As shown in FIG. 5, the capacitor 3 according to the present embodiment includes a winding of a capacitor element 10 a disposed in a region where heat dissipation is required, such as a capacitor element disposed near the center of the container 12. The core portion 26 is provided with a heat dissipating member 24 that has been subjected to alumite treatment, and a portion of the heat dissipating member 24 is in contact with the refrigerant flowing in the cooler 18 (substantially the cooling portion 22). It is inserted in. And the radiation fin 32 is provided in the location of the thermal radiation member 24 penetrated in the cooler 18. As shown in FIG. By providing the heat radiation fins 32, the heat transferred from the capacitor element 10a to the heat radiation member 24 can be efficiently released to the refrigerant, and the heat radiation characteristics of the capacitor element 10a can be improved.

  In the radiating fin 32 shown in FIG. 5, a plurality of pin fins are arranged perpendicular to the refrigerant flow direction with a predetermined interval therebetween. The direction of the plurality of fins is not limited to the above, and may be arranged along the flow of the refrigerant, for example. Further, the fin shape of the heat radiation fin 32 is not limited to a pin fin, and is not particularly limited to a straight fin, a wave fin, or the like. However, by providing the heat radiating member 24 with a plurality of pin fins spaced apart from each other at a predetermined interval in the heat radiating member 24, the refrigerant flowing through the cooling unit 22 is radiated by the heat radiating fins 32. A turbulent flow is formed at the time of collision, and heat exchange between the refrigerant and the radiation fins 32 is promoted. As a result, the heat dissipation characteristics of the capacitor element 10a can be improved. Moreover, in order to ensure insulation with a cooler, especially a refrigerant | coolant, it is preferable that the radiation fin 32 is also anodized.

  As the capacitor elements 10a and 10b, for example, capacitor elements such as plastic film capacitors, ceramic capacitors, aluminum electrolytic capacitors, and electric double layer capacitors may be used, as long as they have a function as a capacitor element. There is no particular limitation. Capacitor elements for plastic film capacitors and ceramic capacitors are formed, for example, by interposing a dielectric film between an anode foil and a cathode foil and laminating or winding them. A dielectric film of a capacitor element for a plastic film capacitor is made of a resin material such as polyethylene terephthalate, polypropylene, or polyethylene naphthalate. A dielectric film of a capacitor element for a ceramic capacitor is made of a ceramic material such as barium titanate. A capacitor element for an aluminum electrolytic capacitor is formed, for example, by interposing electrolytic paper (separator) between an anode aluminum foil and a cathode aluminum foil and laminating or winding them. A capacitor element for an electric double layer capacitor is formed, for example, by interposing a separator between an anode carbon electrode and a cathode carbon electrode, and laminating or winding them. The capacitor elements for aluminum electrolytic capacitors and electric double layer capacitors are impregnated with an electrolytic solution.

  As described above, in the present embodiment, an alumite-treated heat dissipating member is installed in a capacitor element disposed in a region where heat dissipation is required, and a part of the heat dissipating member is in contact with the refrigerant. By inserting it into the cooler, it is possible to improve the heat dissipation characteristics of the capacitor element arranged in a region where it is necessary to ensure heat dissipation, and to suppress the occurrence of defects in the capacitor element. And since the heat of the capacitor element arranged in the area where heat dissipation is required is transmitted to the cooler side via the heat dissipation member, the capacitor arranged in the area where it is not necessary to ensure the heat dissipation characteristics Thermal diffusion to the element side can be suppressed. Accordingly, it is possible to suppress deterioration of the capacitor element disposed in the region where the heat dissipation is not required due to the heat of the capacitor element disposed in the region where the heat dissipation is required.

It is a schematic plan view which shows an example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a schematic cross section which shows an example of a structure of the capacitor | condenser in the AA line of FIG. It is a schematic cross section which shows another example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a schematic diagram which shows the location of the thermal radiation member penetrated in the cooler shown in FIG. It is a schematic cross section which shows another example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a model top view which shows the structure of the conventional capacitor | condenser. It is a schematic cross section which shows an example of a structure of the capacitor | condenser in the AA line of FIG.

Explanation of symbols

  1 to 4 capacitors, 10a, 10b, 34a, 34b capacitor elements, 12, 36 containers, 14, 38 anode bus bars, 16, 40 cathode bus bars, 18, 44 coolers, 18a partitions, 20, 42 fasteners, 22, 46 cooling part, 24 heat radiation member, 26 core part, 28, 30 threaded part, 32 heat radiation fin.

Claims (4)

A capacitor having a plurality of capacitor elements, and a container that accommodates the plurality of capacitor elements and is attached to a cooler,
In the container, a capacitor element disposed in a region where heat dissipation of the capacitor element needs to be ensured is provided with a heat-dissipating member that has been subjected to alumite treatment, and a part of the heat-dissipating member is disposed in the cooler. A condenser, wherein the condenser is inserted into the cooler so as to be in contact with the refrigerant flowing through the condenser.   2. The capacitor according to claim 1, wherein the plurality of capacitor elements are of a wound type.   3. The capacitor according to claim 2, wherein the heat dissipating member is installed on a core portion of a capacitor element disposed in the region, and a part of the heat dissipating member is in contact with a refrigerant flowing in the cooler. Thus, the condenser is inserted into the cooler.   4. The capacitor according to claim 3, wherein a threaded portion is provided at a position of the heat dissipating member inserted into the cooler. 5.

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