JP2023008578A - capacitor - Google Patents

Abstract

To provide a capacitor that can efficiently cool the whole capacitor without using a separate heat radiation member.SOLUTION: A first bus bar 3 includes: a first substrate part 31 that overlaps with a first electrode surface 21 of a capacitor element 2; and a first external connection part 32 that rises from the first substrate part 31. A second bus bar 4 includes: a second substrate part 41 that overlaps with a second electrode surface 22, and proximately faces the first electrode surfaces 21 of all the capacitor elements 2 and the first substrate part 31; and a second external connection part 42 that rises in the same direction as that of the first external connection part 32 from a portion at which the first substrate part 31 and the second substrate part 41 proximately face each other. The second substrate part 41 proximately faces a side wall portion 52 of a case 5. The side wall portion 52 of the case 5, which proximately faces the second substrate part 41, is provided with a cooling part 54 so that cooling means 7 abuts thereon.SELECTED DRAWING: Figure 2

Description

The present invention relates to a capacitor having a capacitor element housed in a case.

Patent Literature 1 discloses cooling the inside of a capacitor by interposing a heat radiating member connected to an external device inside the capacitor. Further, Patent Document 2 discloses that the entire condenser is directly cooled from the outside by bringing a cooler into contact with the side surface of the condenser case.

JP 2013-191805 A JP 2013-84787 A

In Patent Literature 1, interposing the heat radiating member inside the capacitor is troublesome and costly, and the size of the capacitor is increased by the amount of the heat radiating member. In Patent Literature 2, there is a possibility that portions other than the portion where the cooler is brought into contact will be insufficiently cooled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a capacitor capable of efficiently cooling the entire capacitor without using a separate heat radiation member.

The capacitor of the present invention includes a plurality of capacitor elements 2 each having a first electrode surface 21 on one end surface and a second electrode surface 22 on the other end surface, and a first bus bar 3 connected to the first electrode surface 21 . and a second bus bar 4 connected to the second electrode surface 22 are housed in a case 5. The first bus bar 3 includes a first substrate portion 31 overlapping the first electrode surface 21 and the first substrate portion 31 overlapping the first electrode surface 21. The second bus bar 4 overlaps the second electrode surfaces 22 and extends between the first electrode surfaces 21 and the first substrate portions 31 of all the capacitor elements 2 . A second substrate portion 41 that closely faces and a second external connection portion 42 that rises in the same direction as the first external connection portion 32 from a portion where the first substrate portion 31 and the second substrate portion 41 closely face each other. The second substrate portion 41 closely faces at least one of the side wall portion 52, the bottom portion 51, and the opening portion 53 of the case 5, and closely faces the second substrate portion 41, the side wall portion 52, the bottom portion 51, and the opening portion of the case 5. At least one of 53 is characterized by having a cooling portion 54 for abutting the cooling means 7 .

In the capacitor 1 described above, the capacitor element 2 is preferably housed with the second electrode surface 22 facing the bottom 51 of the case 5 .

In the capacitor of the present invention, at least one of the side wall, the bottom, and the opening of the case, which the second bus bar is closely opposed to, has the cooling portion for contacting the cooling means. The second bus bar can be cooled by allowing the temperature to rise. The second substrate portion of the second bus bar overlaps the first electrode surface and faces the first electrode surfaces of all the capacitor elements in close proximity, so that the capacitor elements can be efficiently cooled from both sides. Furthermore, since the second substrate portion also closely faces the first substrate portion of the first bus bar, the first bus bar can also be efficiently cooled.

When the capacitor element is accommodated with the second electrode surface facing the bottom of the case, the second bus bar is provided from the bottom side to the top side of the case, so that the entire capacitor can be efficiently cooled. can.

1 is an exploded perspective view showing a capacitor according to one embodiment of the invention; FIG. 1 is a cross-sectional view of a capacitor; FIG. 1 is a perspective view of a capacitor; FIG. FIG. 4 is a plan view showing a state in which the first bus bar is connected to the capacitor element; FIG. 4 is a plan view showing a state in which a second bus bar is connected to a capacitor element; It is the figure which looked up at the state which connected the 2nd bus-bar to the capacitor element from the bottom. FIG. 5 is a schematic perspective view showing a different form of the second busbar; FIG. 4 is a perspective view showing a different form of the first busbar;

Next, one embodiment of the capacitor of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the capacitor 1 of the present invention includes a capacitor element 2, a first bus bar 3, a second bus bar 4, a case 5 for accommodating them, and a resin filled in the case 5. 6. Each component will be described below, but the concept of "top and bottom" refers to the time of manufacture, more specifically, the time of resin filling, and does not necessarily define the top and bottom of use.

The capacitor element 2 is, for example, a film capacitor formed by winding a metallized film in which a metal is vapor-deposited on an insulating film, and as shown in FIGS. A first electrode surface 21 is provided, and a second electrode surface 22 is provided on the other end surface. These electrode surfaces are formed, for example, by spraying metal. The capacitor element 2 has a bale shape when viewed from the axial direction, and more specifically, has four corners with R (rounds), and between the first electrode surface 21 and the second electrode surface 22 (peripheral surface). ) has a side surface 23 consisting of a flat portion 23a and a curved portion 23b. Then, the first electrode surface 21 is directed upward and the second electrode surface 22 is directed downward, and the flat portions 23a are opposed to each other. , forming a group of capacitor elements. Note that the capacitor element 2 is not limited to a film capacitor, and various capacitor elements such as an electrolytic capacitor and a ceramic capacitor may be used. As for the shape, various shapes such as a columnar shape and a prismatic shape can be adopted. The number can also be changed as appropriate.

The first bus bar 3 is formed by cutting out a conductive metal plate of aluminum, copper, or the like into a predetermined shape and bending it appropriately. and a first external connection portion 32 that rises from the first substrate portion 31 and is used for connection with an external device (not shown).

As shown in FIGS. 1 and 4 , the first substrate portion 31 has a substantially T-shape in plan view and overlaps the first electrode surfaces 21 of all the capacitor elements 2 . Specifically, the extending portion 31a corresponding to the first stroke (longitudinal) of "T" is positioned substantially at the longitudinal center of the capacitor element group in a plan view, and the first electrode surfaces 21 of the two capacitor elements 2 overlaps with A base portion 31 b corresponding to the second stroke (horizontal) of “T” is provided substantially parallel to the longitudinal direction of the capacitor element group and overlaps the first electrode surfaces 21 of the four capacitor elements 2 . A tongue-shaped connecting portion 33 for connecting to the first electrode surface 21 is provided from the outer edge of the first substrate portion 31 .

The first external connection portion 32 extends on the first electrode surface 21 . Moreover, it extends from the outer edge of the extension part 31a side among the outer edges of the base part 31b. Therefore, the first bus bar 3 has a substantially inverted T shape when viewed from the side.

The second bus bar 4 is formed by cutting out a conductive metal plate such as aluminum or copper into a predetermined shape and bending it appropriately. It has a second external connection portion 42 that rises from the second substrate portion 41 and is used for connection with an external device (not shown).

As shown in FIGS. 1 and 2, the second substrate portion 41 includes a lower horizontal portion 41a that overlaps (contacts) the second electrode surface 22 from below and extends upward from one side of the lower horizontal portion 41a to form a capacitor. A vertical portion 41 b that closely faces the side surface 23 of the element 2 , and a vertical portion 41 b that extends laterally from one side of the vertical portion 41 b toward the first electrode surface 21 and closely faces the first electrode surface 21 and the first substrate portion 31 from above. and an upper horizontal portion 41c. Therefore, the cross-sectional shape of the second substrate portion 41 is substantially U-shaped, and covers the periphery of the capacitor element 2 .

The planar shape of the lower horizontal portion 41a is substantially rectangular, and overlaps with the second electrode surfaces 22 of all the capacitor elements 2 as shown in FIG. The lower horizontal portion 41a faces a bottom portion 51 of the case 5, which will be described later. A tongue-shaped connecting portion 43 for connecting to the second electrode surface 22 is provided on the lower horizontal portion 41a. As shown in FIG. 2, the vertical portion 41b also closely faces a side wall portion 52 of the case 5, which will be described later. The upper horizontal portion 41c faces the first electrode surfaces 21 of all the capacitor elements 2 in close proximity, as shown in FIG. Although omitted in FIG. 5, the first substrate portion 31 is interposed between the upper horizontal portion 41c and the first electrode surface 21. As shown in FIG. Accordingly, the upper horizontal portion 41c also faces the first substrate portion 31 in close proximity. Further, the upper horizontal portion 41c is provided with a hole 44 or a notch 45 for exposing the connecting portion 33 upward at a portion facing the connecting portion 33 of the first substrate portion 31 in close proximity.

The second external connection portion 42 extends from a portion on the first electrode surface 21 where the extending portion 31a of the first substrate portion 31 and the upper horizontal portion 41c of the second substrate portion 41 face each other. Moreover, it rises in the same direction as the first external connection portion 32 . The second external connection portion 42 is aligned with the first external connection portion 32 in a direction orthogonal to the plate thickness direction.

As shown in FIG. 1 , the case 5 includes a bottom portion 51 that is substantially rectangular in plan view, and side wall portions 52 that rise upward from four sides of the bottom portion 51 . An opening 53 is provided above the case 5 , and the capacitor element 2 , the first bus bar 3 and the second bus bar 4 are accommodated in the case 5 through the opening 53 . Also, the first external connection portion 32 and the second external connection portion 42 are extended outside the case 5 from the opening portion 53 . The case 5 is made of a non-conductive material such as synthetic resin.

The resin 6 filled in the case 5 is, for example, epoxy resin. However, it is not limited to this, and although various known resins such as urethane resin can be used, it is preferable to adopt a resin having excellent moisture resistance and a resin having high thermal conductivity. The resin 6 is filled so as to bury the first substrate portion 31 and the second substrate portion 41 in addition to the capacitor element 2 . The upper portions of the first external connection portion 32 and the second external connection portion 42 protrude outside the resin 6 . The thickness of the resin (the distance from the surface of the resin to the capacitor element 2) is appropriately changed according to the type and characteristics of the resin used.

Next, assembly of the capacitor 1 will be described. First, the first substrate portion 31 of the first bus bar 3 is overlapped with the first electrode surface 21 of the capacitor element 2 and connected by soldering or the like, and the capacitor element is placed inside the second bus bar 4 having a substantially U-shaped cross section. 2 and the first substrate portion 31 are placed, and the lower horizontal portion 41a of the second substrate portion 41 is overlapped with the second electrode surface 22 of the capacitor element 2 and connected by soldering or the like to form a capacitor module. In this state, the upper horizontal portion 41 c of the second substrate portion 41 is closely opposed to the first electrode surface 21 with the first substrate portion 31 interposed therebetween. Also, the first external connection portion 32 and the second external connection portion 42 protrude in the same direction. The first bus bar 3 and the second bus bar 4, and the second bus bar 4 and the first electrode surface 22 are insulated by an insulating member such as insulating paper (not shown) or a gap (which may be filled with the resin 6). They are not electrically connected to each other.

Subsequently, the capacitor module is housed in the case 5 through the upper opening 53 . At this time, the first external connection portion 32 and the second external connection portion 42 are accommodated so that the first external connection portion and the second external connection portion extend out of the case 5 from the opening 53 ( See Figure 3). In addition, the vertical portion 41b of the second bus bar 4 is closely opposed to the side wall portion 52 of the case 5. As shown in FIG. Then, the case 5 is filled with the resin 6 and the capacitor element 2 is sealed to complete the production of the capacitor.

A side wall portion 52 of the case 5, which the vertical portion 41b is closely opposed to, has a cooling portion 54 for abutting the cooling means 7 from the outside (see FIG. 2). Therefore, by bringing the cooling means 7 into contact with the cooling portion 54, the vertical portion 41b can be cooled. A second bus bar 4 is provided so as to cover the capacitor element 2 . Specifically, the vertical portion 41 b closely faces the side surface 23 of the capacitor element 2 , the upper horizontal portion 41 c closely faces the first electrode surface 21 , and the lower horizontal portion 41 a overlaps the second electrode surface 22 . Therefore, the capacitor element 2 can be cooled from various directions by the cooled second substrate portion 41 . In particular, since the longitudinal surface of the capacitor element group in which a plurality of capacitor elements 2 are arranged side by side and the vertical portion 41b are closely opposed to each other, the capacitor elements 2 can be efficiently cooled. Furthermore, since the upper horizontal portion 41c also closely faces the first substrate portion 31 of the first bus bar 3, the first bus bar 3 can also be cooled. As a result, the entire capacitor can be efficiently cooled without providing a separate component such as a heat radiating member for cooling, and cost reduction and miniaturization of the capacitor can be achieved. In addition, since the upper horizontal portion and the first substrate portion, which have opposite polarities, are closely opposed to each other, it is possible to reduce the ELS due to the cancellation effect.

The lower horizontal portion 41a of the second bus bar 4 also faces the bottom portion 51 of the case 5 in close proximity. Therefore, the cooling part 54 may be provided in the bottom part 51 of the case 5 . Also in this case, the entire condenser can be efficiently cooled through the second bus bar 4 . Of course, the cooling portion 54 may be provided on both the side wall portion 52 and the bottom portion 51 of the case 5 . Further, the upper horizontal portion 41c of the second bus bar 4 is located on the side of the opening 53 of the case 5 and faces the opening 53 of the case 5 in close proximity. The opening 53 may be used as the cooling portion 54 because it is closely opposed to the enclosed surface (opening surface). Since the opening 53 and the resin surface are substantially parallel to each other, it can be said that the resin surface serves as the cooling portion 54 in this state.

FIG. 7 shows another form of the second bus bar 4. As shown in FIG. The one in FIG. 7A is provided with verticals 41b on three sides. In other words, it has a box shape with an opening on one side. In FIG. 7B, two vertical portions 41b are provided so as to face each other, and have a square tube shape (substantially square cross section). When such a second bus bar 4 is used, a large number of side wall portions 52 of the case 5 are formed so as to face the second bus bar 4 in close proximity. can be cooled.

FIG. 8 shows another form of the first bus bar 3. As shown in FIG. 8A, the extending portion 31a has a vertical portion 31c that overlaps or closely faces the side surface 23 of the capacitor element 2. In FIG. 8B, the base 31b has a vertical portion 31c that overlaps or closely faces the side surface 23. FIG. When the first busbars 3 having these different forms are used, the side surfaces 23 of the capacitor element 2 can be cooled by the first busbars 3 cooled via the second busbars 4 . In particular, the cooling effect can be improved by providing the vertical portion 31c at a location where the second bus bar 4 is not closely opposed. Further, since the vertical portion 31c is closely opposed to the side wall portion 52 of the case 5, the cooling means 7 may be brought into contact with the side wall portion 52 facing the vertical portion 31c.

Although the 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 embodiment, the first electrode surface 21 of the capacitor element 2 faces upward, but it may face sideways. The cooling means may be of a form in which the inside is hollow and a cooling medium flows through the cavity for cooling, or a form in which a large number of fins are provided to promote heat dissipation. Various coolers can be used. Cooling means may also be provided at locations where the second busbars 4 do not face each other closely. For example, in FIG. 2, the cooling means is provided on the right side of the paper surface, but the cooling means may also be provided on the left side.

1 capacitor 2 capacitor element 21 first electrode surface 22 second electrode surface 23 side surface 23a flat portion 23b curved surface portion 3 first bus bar 31 first substrate portion 31a extension portion 31b base portion 31c vertical portion 32 first external connection portion 33 connection portion 4 Second bus bar 41 Second substrate portion 41a Lower horizontal portion 41b Vertical portion 41c Upper horizontal portion 42 Second external connection portion 43 Connection portion 44 Hole 45 Notch 5 Case 51 Bottom portion 52 Side wall portion 53 Opening portion 54 Cooling portion 6 Resin 7 Cooling means

Claims (2)

a plurality of capacitor elements having a first electrode surface on one end surface and a second electrode surface on the other end surface; a first bus bar connected to the first electrode surface; and a second electrode surface connected to the second electrode surface. 2 busbars and a capacitor housed in a case,
The first bus bar includes a first substrate portion overlapping the first electrode surface and a first external connection portion rising from the first substrate portion,
The second bus bar includes: a second substrate portion that overlaps the second electrode surface and closely faces the first electrode surfaces of all the capacitor elements and the first substrate portion; a second external connection portion rising in the same direction as the first external connection portion from a portion facing the second substrate portion in close proximity;
The second substrate part closely faces at least one of the side wall part, the bottom part and the opening part of the case,
A capacitor characterized in that at least one of a side wall portion, a bottom portion, and an opening portion of a case that closely faces the second substrate portion is provided with a cooling portion for abutting a cooling means. 2. The capacitor according to claim 1, wherein the capacitor element is housed with the second electrode surface facing the bottom surface of the case.

Images