JP2009038135A - Capacitor device and manufacturing method thereof - Google Patents

Abstract

A capacitor device that can more reliably prevent a short-circuit failure is provided.
A capacitor module 24 in which a plurality of capacitor elements 12 are connected and a bus bar 20 as a terminal member is connected to an end thereof is housed in an outer case 14 made of a metal material. An insulating layer 16 is formed on the inner side surface of the outer case 14 by applying a mica paint containing mica in advance. A resin 18 for improving vibration resistance and moisture resistance is filled between the outer case 14 and the capacitor module 24.
[Selection] Figure 1

Description

  The present invention relates to a capacitor device in which one or more capacitor elements are unitized.

  In recent years, vehicles using an electric motor as a drive source, for example, an electric vehicle or a hybrid vehicle using an engine and an electric motor together are known. In such a vehicle, a large amount of electric power is required at the time of starting or the like, and therefore a capacitor device that can be discharged and charged is appropriately mounted. Such a capacitor device is usually mounted in the same place as other drive-related members such as a battery and an inverter. The following Patent Documents 1 to 4 disclose various configurations of capacitor devices.

  Patent Document 1 discloses disposing a resin laminated mica plate for preventing moisture intrusion at the opening of the case, or at the opening and the side and / or the bottom. Patent Document 2 discloses that a heat insulating layer made of a ceramic coating material or a mica-containing material mainly containing zirconia, silica, silicon nitride, or the like and a resin layer are formed on the outer peripheral surface of the capacitor element. . Patent Document 3 discloses an electronic component outer container formed by squeezing a laminated plate coated with a modified polyolefin resin layer. Patent Document 4 includes an aluminum case obtained by drawing a polyamide-based insulating resin layer. , Respectively.

  2. Description of the Related Art A capacitor device mounted on a vehicle or the like is obtained by housing a capacitor module configured by electrically connecting a plurality of capacitor elements with terminal members called bus bars in an outer case made of metal such as aluminum. The periphery of the capacitor module stored in the outer case is filled with a resin for absorbing the vibration of the capacitor module during driving and preventing moisture from entering, specifically, urethane resin, epoxy resin, or the like. .

  In addition, in order to ensure electrical insulation between the bus bar connected to the capacitor module and the outer case made of a metal material, the capacitor module is previously stored in a PPS case made of highly insulating PPS (polyphenylene sulfide) resin. In addition, the PPS case may be stored in the exterior case. In this case, the PPS resin, which is an insulating material, is always interposed between the bus bar and the outer case. Thereby, a short circuit failure of the capacitor device via the outer case is prevented.

JP 2003-289011 A JP 61-182213 A JP 2-111008 A JP-A-3-295215

  By the way, the capacitor module may fail for some reason and generate excessive heat. As the capacitor module generates heat, the resin and PPS case for improving vibration resistance and moisture resistance filled around the capacitor module may carbonize, and the outer case and the bus bar of the capacitor module may be electrically connected. is there.

  In this case, a short circuit failure of the capacitor device through the outer case occurs. However, none of the configurations according to Patent Documents 1 to 4 can sufficiently prevent a short-circuit failure of the capacitor device.

  Therefore, an object of the present invention is to provide a capacitor device that can more reliably prevent a short-circuit failure, and a manufacturing method thereof.

  The capacitor device according to the present invention includes a capacitor module that connects one or more capacitor elements and has a terminal member connected to an end thereof, and a metal case that houses the capacitor module, and has an insulating layer on an inner surface thereof And a member that is filled between the metal case and the capacitor module and absorbs vibration of the capacitor module and prevents moisture from entering, and the insulating layer has an insulating property. And a heat resistance higher than the heat generation temperature of the capacitor module at the time of internal failure.

  In a preferred aspect, the insulating layer is made of a mica-containing material. In another preferred embodiment, the insulating layer is formed by applying a mica-containing paint on the inner surface of the metal case. In another preferred aspect, the insulating layer has a thicker portion in the inner surface of the metal case facing the terminal than the other portion.

  Another method of manufacturing a capacitor device according to the present invention is to connect one or more capacitor elements and connect a terminal member to an end thereof to form a capacitor module, and to form the capacitor module with an insulating property. And a step of storing the insulating layer made of a material having a heat resistance equal to or higher than the heat generation temperature of the capacitor module at the time of an internal failure in a metal case formed in advance, and the vibration resistance between the metal case and the capacitor module Filling a member for improving moisture resistance.

  According to the present invention, an insulating layer having sufficient heat resistance is formed by applying an insulating material (mica-containing material) to the inner surface of the exterior case without any gap. As a result, it is possible to reliably prevent a short circuit failure of the capacitor device via the outer case.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic plan view and a schematic side view of a capacitor device 10 according to an embodiment of the present invention. For ease of viewing, the illustration of the members above the capacitor element 12 is omitted in FIG. 1A, and the members on the front side of the bus bar 20 are omitted in FIG. 1B. FIG. 2 is an enlarged view of a portion A in FIG.

  The capacitor device 10 is configured by housing a capacitor module 24 in an outer case 14 and filling a resin for improving vibration resistance and moisture resistance around the capacitor module 24. The capacitor module 24 is formed by connecting a plurality of capacitor elements 12. The capacitor element 12 is formed by winding a metallized film having a metal layer formed on one or both sides of a plastic film by a technique such as metal vapor deposition. Capacitor elements 12 wound in a cylindrical shape are pressed and molded, and then taped and connected every predetermined number.

  Thereafter, electrodes 12a are formed on both ends of each capacitor element 12 by a technique such as metallicon spraying. The bus bar 20 is soldered to this electrode. The bus bar 20 is made of a conductive material such as copper, and functions as a terminal member that electrically connects the capacitor elements. By connecting the bus bar 20 to each capacitor element 12, the capacitor module 24 is completed. An external terminal 22 protruding upward is connected to the end of the bus bar 20.

  The capacitor module 24 completed with the bus bar 20 connected is housed in the outer case 14 in order to ensure the mechanical rigidity of the capacitor device 10. The outer case 14 is a box-like body whose upper surface is completely open, and is usually made of a metal material such as aluminum. In the periphery of the capacitor module 24 accommodated in the outer case 14, in other words, in the gap formed between the capacitor module 24 and the outer case 14, a resin 18 for improving vibration resistance and moisture resistance, more specifically, Is filled with epoxy resin, urethane resin or the like.

  The resin 18 for vibration resistance and moisture resistance is filled for the purpose of absorbing vibration of the capacitor module 24 and preventing moisture from entering. In other words, the capacitor module 24 is likely to generate vibrations and noise caused by the vibrations when driven. By filling the periphery of the capacitor module 24 with the resin 18 for improving vibration resistance and moisture resistance, the vibration of the capacitor module 24 is absorbed, and deterioration of the capacitor module 24 due to the vibration, noise, and the like are reduced. . Further, moisture can be prevented from entering the capacitor module 24 from the outside, and deterioration of the capacitor module 24 due to moisture absorption can be prevented.

  Of course, the bus bar 20 connected to each capacitor element 12 needs to be electrically insulated from the outer case 14. When the bus bar 20 is electrically connected to the outer case 14 made of a metal material, the pair of bus bars 20 connected to both ends (both poles) of the capacitor element 12 through the outer case 14 are short-circuited, and thus the capacitor device 10 is This is to cause a short circuit failure.

  Therefore, conventionally, the capacitor module 24 has been stored in a PPS case made of PPS resin having insulation properties. That is, in the conventional capacitor device 10, the capacitor module 24 is first housed in a PPS case made of an insulating material. Subsequently, a resin 18 for improving vibration resistance and moisture resistance was filled between the PPS case and the capacitor module 24, and then the capacitor module 24 was housed in the outer case 14 together with the PPS case.

  In this case, an insulating PPS resin is always interposed between the outer case 14 and the capacitor module 24. As a result, the bus bar 20 connected to the capacitor module 24 and the outer case 14 are insulated, and a short circuit failure is prevented.

  However, while PPS resin is excellent in insulation, it has low heat resistance. As a result, there is a problem that when the capacitor module 24 generates heat due to a failure, for example, a failure associated with an excessive power supply, carbonization easily occurs. That is, the heat resistance of the PPS resin is higher than that of other resin materials, but is actually around 200 ° C.

  On the other hand, when the capacitor module 24 fails for some reason, heat is generated, and the periphery of the capacitor module 24 may reach a high temperature, specifically, around 500 ° C. As the temperature rises excessively, the resin 18 disposed in the periphery of the capacitor module 24 for improving vibration resistance and moisture resistance and the PPS case are carbonized, and the bus bar 20 connected to the capacitor module 24 The exterior case 14 may be electrically connected. Hereinafter, a failure of the capacitor module 24 caused by a cause other than a short circuit, such as excessive power supply, is referred to as an “internal failure” and is distinguished from a short circuit failure.

  In order to solve the problem of the occurrence of the short-circuit failure as described above, in this embodiment, the insulating layer 16 having sufficient heat resistance is formed on the inner surface of the outer case 14 instead of the PPS case. The insulating layer 16 is formed of a material having an insulating property and a heat resistance equal to or higher than the heat generation temperature (500 ° C. in the present embodiment) of the capacitor module 24 when an internal failure occurs.

  More specifically, in this embodiment, the insulating layer 16 is formed by applying a mica paint containing mica (mica) to the inner side surface of the outer case 14. Here, as is well known, mica has insulating properties and high heat resistance (900 ° C.). By forming the insulating layer 16 with such a paint containing mica, even if the capacitor module 24 becomes high temperature due to the occurrence of an internal failure, the insulating layer 16 is not carbonized, and the bus bar 20 connected to the capacitor module 24 Insulation with the metal forming the outer case 14 is maintained. As a result, short circuit failure is reliably prevented.

  Further, by forming the insulating layer 16 on the inner surface of the outer case 14, the manufacturing process of the capacitor device 10 can be simplified as compared with the conventional case. This will be described with reference to FIG. FIG. 3 is a flowchart showing a comparison of the manufacturing flow of the present embodiment and the conventional capacitor device 10. In FIG. 3, arrows and blocks indicated by broken lines indicate the flow of the conventional manufacturing process.

  Regarding the manufacture of the capacitor device 10, the flow up to the manufacture of the capacitor module 24 is the same in this embodiment and the related art. That is, when the capacitor device 10 is manufactured, first, the metallized film is wound and formed by pressing to form the capacitor element 12 (S10). Subsequently, the formed capacitor elements 12 are taped and connected every predetermined number (S12). If a plurality of capacitor elements 12 are connected, an electrode is formed on the end of each capacitor element 12 by a technique such as metallized thermal spraying (S14). Then, the capacitor | condenser module 24 is completed by soldering the bus bar 20 to each electrode (S16).

  Once the capacitor module 24 is completed, conventionally, the capacitor module 24 is subsequently stored in the PPS case (S22). Then, a resin 18 for improving vibration resistance and moisture resistance is filled in the gap formed between the PPS case and the capacitor module 24 (S24). The filled resin 18 for improving vibration resistance and moisture resistance is cured, so that the PPS case and the capacitor module 24 are integrated. Then, after the resin 18 for improving vibration resistance and moisture resistance is cured, the capacitor module 10 is housed in the outer case 14 together with the PPS case, thereby completing the manufacture of the capacitor device 10 (S26).

  On the other hand, in the present embodiment, steps S10 to S16 are the same as in the prior art, but after the capacitor module 24 is completed, the capacitor module 24 is directly stored in the outer case 14 (S18). Note that an mica coating is applied in advance to the inner side surface of the outer case 14 to form the insulating layer 16. If the capacitor module 24 is housed in the exterior case 14, the interior of the exterior case 14 is filled with a resin 18 for improving vibration resistance and moisture resistance (S20). When the resin 18 for improving the vibration resistance and moisture resistance is cured, the manufacture of the capacitor device 10 is completed.

  As is apparent from the above description and FIG. 3, the capacitor module 24 is conventionally stored twice in the case (S22, S26). In the present embodiment, the capacitor module 24 is directly connected. It is stored in the outer case 14 (S18). In other words, according to the present embodiment, the step of housing the capacitor module 24 in the PPS case can be omitted. As a result, the manufacturing process of the capacitor device 10 can be simplified as compared with the conventional method. Moreover, since the process of forming the insulating layer 16 of the outer case 14 can be performed in parallel with the process of manufacturing the capacitor module 24, the time required for manufacturing the capacitor device 10 can be shortened as compared with the conventional case.

  As is clear from the above description, according to the present embodiment, it is possible to reliably prevent a short-circuit failure of the capacitor device 10, and it is possible to reduce the labor and time required for its manufacture.

  In this embodiment, the insulating layer 16 is formed by applying a mica paint, but the insulating layer 16 may naturally be formed by other methods. For example, at present, mica sheets in the form of mica are distributed in the market. The insulating layer 16 may be formed by adhering this mica sheet to the inner side surface of the outer case 14 without a gap.

  In addition, the main material of the insulating layer 16 may be other materials such as ceramic as long as the material has sufficient insulation and heat resistance.

  Further, the thickness of the insulating layer 16 may be appropriately changed according to the relative positional relationship with the capacitor module 24 housed in the outer case 14. For example, the portion of the inner surface of the outer case 14 that faces the bus bar 20 is required to have the highest insulation and heat resistance. Therefore, the insulating layer 16 formed in the portion facing the bus bar 20 on the inner surface of the outer case 14 may be thicker than the insulating layer 16 formed in the other portion.

It is the schematic plan view and schematic side view of the capacitor | condenser apparatus which are embodiment of this invention. It is the A section enlarged view in Fig.1 (a). It is a flowchart which shows the flow of manufacture of a capacitor | condenser apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Capacitor device, 12 Capacitor element, 12a Electrode, 14 Outer case, 16 Insulating layer, 18 Resin for vibration resistance and moisture resistance, 20 Bus bar, 22 External terminal, 24 Capacitor module

Claims (5)

A capacitor module in which one or more capacitor elements are coupled and a terminal member is connected to an end thereof;
A metal case for storing the capacitor module, wherein a metal case having an insulating layer formed on the inner surface thereof;
A member that is filled between the metal case and the capacitor module and absorbs vibration of the capacitor module and prevents moisture intrusion;
With
The said insulating layer consists of material provided with insulation and heat resistance more than the heat_generation | fever temperature of the capacitor | condenser module at the time of an internal failure, The capacitor | condenser apparatus characterized by the above-mentioned. The capacitor device according to claim 1,
The capacitor device, wherein the insulating layer is made of a mica-containing material. The capacitor device according to claim 2,
The said insulating layer is formed by apply | coating a mica containing coating material on the inner surface of a metal case, The capacitor | condenser apparatus characterized by the above-mentioned. The capacitor device according to any one of claims 1 to 3,
The capacitor device according to claim 1, wherein a portion of the inner surface of the metal case facing the terminal is thicker than other portions. Connecting one or more capacitor elements and connecting a terminal member to the end thereof to form a capacitor module;
Storing the formed capacitor module in a metal case in which an insulating layer made of a material having insulation properties and heat resistance equal to or higher than the heat generation temperature of the capacitor module at the time of internal failure is formed;
Filling a member for improving vibration resistance and moisture resistance between the metal case and the capacitor module;
A method of manufacturing a capacitor device, comprising:

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