JP2013197348A - Capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor which allows for cost reduction when compared with prior art.SOLUTION: (1) The capacitor includes a case 20, a capacitor element 30, a bus bar 40, and a cover 50. The case 20 includes a case body 21 made of metal and having an aperture 21a, and a case lid 22 fixed to the case body 21 and closing the aperture 21a thereof. The capacitor element 30 is housed in the case 20. The bus bar 40 includes a bus bar first part 41 located in the case 20 and fixed to the capacitor element 30, a bus bar second part 42 located on the outside of the case 20, and a case insertion part 43 through which the case 20 is inserted. The cover 50 is constituted by shaping an insulating resin film 51 along the inner surface of the case 20, and housed between the capacitor element 30 and the case 20. (2) The cover 50 is a vacuum molding.

Description

  The present invention relates to a capacitor used in an automobile or the like.

Japanese Patent Laid-Open No. 2008-288242 discloses that a capacitor element and a bus bar fixedly attached to the capacitor element are accommodated in a case body having an upper surface opened, and the case body is filled with an epoxy resin that is a thermosetting resin. The capacitor is disclosed in which the capacitor element and the bus bar are wrapped (covered) with an epoxy resin except for the external connection terminal portion of the bus bar.
The epoxy resin is provided to prevent water vapor (moisture) from entering the capacitor element from the surroundings.

However, the conventional capacitor has the following problems.
Since the time required for curing the epoxy resin is relatively long, the time required for manufacturing the capacitor becomes relatively long, and it is difficult to reduce the cost by shortening the cycle time.

JP 2008-288242 A

  An object of the present invention is to provide a capacitor capable of reducing the cost as compared with the prior art.

The present invention for achieving the above object is as follows.
(1) having a case, a capacitor element, a bus bar, and a cover;
The case is made of metal, and includes a case main body having an opening, and a case lid fixed to the case main body and closing the opening of the case main body.
The capacitor element is accommodated in the case,
The bus bar includes a bus bar first portion positioned in the case and fixed to the capacitor element, a bus bar second portion positioned outside the case, the bus bar first portion, and the bus bar second portion. A case insertion portion that is positioned between and inserts the case, and
The cover is made of a resin film having insulating properties formed into a shape along the inner surface of the case, and is accommodated between the capacitor element and the case in the case.
Capacitor.
(2) The capacitor according to (1), wherein the cover is a vacuum molded product.

According to the capacitor (1), the following effects can be obtained.
Since the case is made of metal and includes a case main body having an opening and a case lid fixed to the case main body to close the opening of the case main body, water vapor (water) around the case in the case Can be prevented from entering the case. Therefore, unlike the conventional case, the epoxy resin can be abolished. Therefore, the cost can be reduced by shortening the cycle time as compared with the conventional case.

According to the capacitor (1), the following effects can be further obtained.
Since the cover made of a resin film having insulating properties is disposed between the capacitor element and the case, the capacitor element and the case can be insulated even if the case is made of metal.

According to the capacitor (2), the following effects can be obtained.
Since the cover is a vacuum-formed product, the cover can be formed inexpensively and easily as compared with the case where the cover is formed by other methods.

It is sectional drawing of the capacitor | condenser of this invention Example. However, the sectional view of the capacitor element is omitted. It is a disassembled perspective view of the capacitor | condenser of this invention Example. It is a schematic process drawing which shows the manufacturing method of the cover in the capacitor | condenser of this invention Example.

Hereinafter, a capacitor according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the capacitor 10 according to the embodiment of the present invention includes a case 20, a capacitor element 30, a bus bar 40, and a cover 50.

  The case 20 is made of metal, and is made of, for example, aluminum or iron that is cheaper than an epoxy resin. Since the case 20 is made of metal, the case 20 has a water vapor barrier property. The case 20 includes a case main body 21 having an opening 21 a and a case lid 22 that is fixed to the case main body 21 and closes the opening 21 a of the case main body 21.

The case body 21 includes a bottom wall 21b and a side wall 21c that rises upward from the outer edge of the bottom wall 21b. The upper end of the case body 21 is an opening 21a that opens upward.

  The case lid 22 has a flat plate shape or a substantially flat plate shape. The case lid 22 is fixed to the case main body 21 by joining (welding) the outer edge of the case lid 22 to the side wall 21c of the case main body 21 continuously over the entire circumference without any gap. The case lid 22 is joined to the case body 21 by, for example, vibration welding, laser welding, or the like.

Either one of the case body 21 and the case lid body 22 is provided with a bus bar insertion hole 22a through which the bus bar 40 is inserted. In the illustrated example, the case lid 22 is provided with a bus bar insertion hole 22a.

  The capacitor element 30 is configured by winding or laminating a dielectric film provided with a metal vapor deposition electrode, and metallicon electrodes (not shown) are formed at both ends of the winding or lamination. The capacitor element 30 is located in the case 20 and is accommodated in the case 20. The capacitor element 30 is supported by the cover 50 in the case 20.

  The bus bar 40 is made of metal and has a long and thin plate shape. A pair of bus bars 40 are provided so as to correspond to the metallicon electrodes at both ends of the capacitor element 30. One of the pair of bus bars 40 is fixedly attached (joined) to one end of the capacitor element 30 by soldering, and is connected to a metallized electrode at one end of the capacitor element 30. The other of the pair of bus bars 40 is fixedly attached (joined) to the other end of the capacitor element 30 by soldering, and is connected to the metallicon electrode at the other end of the capacitor element 30.

  The bus bar 40 extends from the inside of the case 20 to the outside of the case 20. The bus bar 40 is positioned between the bus bar first portion 41 located inside the case 20, the bus bar second portion 42 located outside the case 20, and the bus bar first portion 41 and the bus bar second portion 42. And a case insertion portion 43 through which the case 20 is inserted.

The bus bar 40 is fixedly attached to the capacitor element 30 at the bus bar first portion 41. The bus bar second portion 42 is a terminal portion for external connection. The bus bar 40 is inserted through the bus bar insertion hole 22 a of the case 20 at the case insertion portion 43. The case insertion portion 43 (bus bar 40) and the case 20 are not in contact with each other. The gap between the case insertion portion 43 and the case 20 is preferably filled with a material (not shown) having a water vapor barrier property.

The cover 50 is configured by molding (shaping) a flat resin film (resin sheet) 51 shown in FIG. 3A into a shape (three-dimensional shape) along at least a part of the inner surface of the case 20. Is done. The cover 50 is housed between the capacitor element 30 and the case 20 in the case 20 in a state of being molded in advance.

The cover 50 is made of an insulating material. Since the case 20 has the water vapor barrier property, the water vapor barrier property is not necessary for the cover 50. For this reason, it is desirable that the cover 50 be made of a material that does not consider water vapor barrier properties in order to reduce material costs. For example, relatively inexpensive PP (polypropylene), PE (polyethylene), and PET (polyethylene). It is desirable that it is composed of a single layer structure such as terephthalate). However, the cover 50 may be made of a material having a water vapor barrier property such as an aluminum laminate film.

The cover 50 is, for example, a vacuum formed product. A method of forming the cover 50 when the cover 50 is a vacuum formed product will be described.
First, (i) as shown in FIG. 3A, the edge portion 51 a of the flat resin film 51 is clamped by the frame 61 of the vacuum forming machine 60.
Thereafter, (ii) as shown in FIG. 3B, the resin film 51 is heated and softened, and set in the mold 62 of the vacuum forming machine 60.
Thereafter, (iii) as shown in FIG. 3C, the resin film 51 is brought into close contact with the mold 62 by being sucked from the holes 62 a provided in the mold 62.
Thereafter, (iv) as shown in FIG. 3D, the resin film 51 is released from the mold after cooling and the edge 51a is cut off to form the cover 50.

As shown in FIG. 1, the cover 50 is provided with a bus bar insertion hole 52 through which the bus bar first portion 41 of the bus bar 40 is inserted as necessary. The bus bar insertion hole 52 is formed by opening a hole in the cover 50 after the cover 50 is formed.
The cover 50 may have a one-part configuration or a multiple-part configuration. In the illustrated example of the present invention, a case is shown in which the cover 50 has a two-part configuration of a cover lower 50a and a cover upper 50b. When the cover 50 has a multi-part configuration, each cover 50 may have the same shape or a non-identical shape except for the presence or absence of the bus bar insertion hole 52. When the cover 50 has a multi-part configuration, the covers 50 may be in contact with each other or may not be in contact with each other.

Here, a manufacturing method in the case where the cover 50 of the capacitor 10 according to the embodiment of the present invention has a two-part configuration of the cover lower 50a and the cover upper 50b will be described.
First, (i) the case main body 21 and the case lid 22 are respectively formed. Further, the cover 50 (the cover lower 50a and the cover upper 50b) is formed. Further, the capacitor element 30 and the bus bar 40 are fixed to each other.
2, (ii) the cover lower 50a, the element element 30 to which the bus bar 40 is fixed, and the cover upper 50b are combined with the cover lower 50a, the element element 30 to which the bus bar 40 is fixed, and the cover upper. Insert and set in the case body 21 in the order of 50a.
Thereafter, (iii) the case lid 22 is set (placed) on the case main body 21 and the case lid 22 and the case main body 21 are joined (welded) over the entire circumference.

Next, the operation and effect of the embodiment of the present invention will be described.
Since the case 20 is made of metal and includes a case main body 21 having an opening 21a and a case lid 22 fixed to the case main body 21 and closing the opening 21a of the case main body 21, It is possible to prevent water vapor (moisture) around the case 20 from entering the case 20. Therefore, unlike the conventional case, the epoxy resin can be abolished. Therefore, the cost can be reduced by shortening the cycle time as compared with the conventional case.

Since the cover 50 made of a resin film having insulating properties is disposed between the capacitor element 30 and the case 20, the gap between the capacitor element 30 and the case 20 is not limited even when the case 20 is made of metal. Can be insulated.

Since the cover 50 is a vacuum-formed product, when the cover 50 is formed by other methods (for example, the cover is made of a resin film with a double-sided tape, the release paper of the double-sided tape is peeled off, and the cover is attached to the case or the capacitor element) Compared to the case), the cover 50 can be molded at low cost and easily.

10 Capacitor 20 Case 21 Case body 21a Case body opening 21b Case body bottom wall 21c Case body side wall 22 Case lid 22a Case bus bar insertion hole 30 Capacitor element 40 Bus bar 41 Bus bar first portion 42 Bus bar second Part 43 Case insertion part 50 Cover 50a Cover lower 50b Cover upper 51 Resin film 51a Resin film edge 52 Cover bus bar insertion hole 60 Vacuum forming machine 61 Vacuum forming machine frame 62 Vacuum forming machine mold

Claims (2)

A case, a capacitor element, a bus bar, and a cover;
The case is made of metal, and includes a case main body having an opening, and a case lid fixed to the case main body and closing the opening of the case main body.
The capacitor element is accommodated in the case,
The bus bar includes a bus bar first portion positioned in the case and fixed to the capacitor element, a bus bar second portion positioned outside the case, the bus bar first portion, and the bus bar second portion. A case insertion portion that is positioned between and inserts the case, and
The cover is made of a resin film having insulating properties formed into a shape along the inner surface of the case, and is accommodated between the capacitor element and the case in the case.
Capacitor.   The capacitor according to claim 1, wherein the cover is a vacuum formed product.

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