Capacitors, inverters, and vehicles

Abstract

To provide a capacitor that can suppress misalignment of external terminals and defects in appearance. [Solution] The capacitor 1 comprises a capacitor element 2 having electrodes 3, a first busbar 41 having an element connection portion 6 connected to the electrodes 3 and a first connecting portion 51, a second busbar 42 having a second connecting portion 52 connected to the first connecting portion 51 and an external terminal 71, a case 8 having an opening 81, a bottom portion 82 facing the opening 81, and a side wall portion 83 extending from the bottom portion 82 to the opening 81, housing the capacitor element 2 and the first busbar 41, with a part of the second busbar 42 embedded in it, and a resin-filled portion 9 filled inside the case 8. The second connecting portion 52 is exposed inside the case 8 near the opening 81. The external terminal 71 is exposed outside the case 8 from a location near the bottom portion 82. The connecting portion between the first connecting portion 51 and the second connecting portion 52 is located inside the resin-filled portion 9.

Description

Technical Field

[0001] The present disclosure generally relates to capacitors, inverters, and vehicles, and more particularly to a capacitor provided with a bus bar, an inverter using this capacitor, and a vehicle.

Background Art

[0002] Patent Document 1 discloses a case-molded capacitor. This case-molded capacitor is composed of a resin case having an opening and a capacitor sub-assembly housed inside the resin case. An insulating paper that insulates one electrode of the capacitor element from the other bus bar is attached to the capacitor element of the capacitor sub-assembly. All parts of the capacitor sub-assembly except the external terminals of the pair of bus bars are molded inside the resin case by a resin filling material. On one bus bar, a pressing piece for suppressing the lifting of the insulating paper attached to the capacitor element is formed. The pressing piece is formed at a position laterally displaced from the overhanging piece in the bus bar body of one bus bar.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the case-molded capacitor of Patent Document 1 had the following problems.

[0005] First, as described in paragraph

[0017] of Patent Document 1, if a resin filler is filled into the resin case while the capacitor subassembly is set inside the resin case, there is a risk that the external terminals of the capacitor subassembly will be misaligned relative to the resin case. In order to suppress this misalignment, it is necessary to fix the capacitor subassembly and the resin case using a suitable jig before filling with the filler, but such work is complicated.

[0006] Next, in Patent Document 1, since the external terminals protrude from the opening of the resin case, when filling the inside of the resin case with resin filler, there is a risk that the filler may crawl up the external terminals or adhere to the external terminals, resulting in a defect in the appearance of the external terminals.

[0007] The purpose of this disclosure is to provide a capacitor, inverter, and vehicle that can suppress misalignment of external terminals relative to the case without requiring complicated work, and also suppress cosmetic defects of the external terminals. In cases where the capacitor has multiple external terminals, the purpose of this disclosure will be considered achieved if cosmetic defects of at least some of the external terminals are suppressed. [Means for solving the problem]

[0008] A capacitor according to one aspect of the present disclosure comprises a capacitor element having electrodes, an element connection portion connected to the electrodes, a first busbar having a first connecting portion, a second busbar having a second connecting portion connected to the first connecting portion, and an external terminal, a case having an opening, a bottom portion facing the opening, and a side wall portion extending from the bottom portion to the opening, housing the capacitor element and the first busbar, with a portion of the second busbar embedded in it, and a resin-filled portion filled inside the case. The second connecting portion is exposed inside the case at a location closer to the opening than the bottom portion. The external terminal is exposed outside the case at a location closer to the bottom portion than the opening. The connecting portion between the first connecting portion and the second connecting portion is located within the resin-filled portion.

[0009] A capacitor according to one aspect of the present disclosure comprises a capacitor element having a pair of electrodes, a pair of first busbars connected one-to-one with the pair of electrodes, a pair of second busbars connected one-to-one with the pair of first busbars, a case housing the capacitor element and the pair of first busbars, with a portion of each of the pair of second busbars embedded in it, and a resin-filled portion filled in the case. Each of the pair of first busbars has an element connection portion connected to one of the pair of electrodes and a first connecting portion. Each of the pair of second busbars has a second connecting portion connected to the first connecting portion, an external terminal, and a planar portion located between the second connecting portion and the external terminal. The case has an opening, a bottom portion facing the opening, and a side wall portion extending from the bottom portion to the opening. The external terminal is exposed to the outside of the case from a location closer to the bottom portion than the opening. At least a portion of the planar portions of each of the pair of second busbars are embedded in the case and facing each other.

[0010] An inverter according to one aspect of the present disclosure includes the capacitor.

[0011] A vehicle according to one aspect of this disclosure is equipped with the inverter. [Effects of the Invention]

[0012] According to this disclosure, misalignment of external terminals relative to the case can be suppressed without requiring complicated procedures, and cosmetic defects of the external terminals can also be suppressed. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a perspective view showing a capacitor according to the first embodiment. [Figure 2] Figure 2 is a plan view of the same capacitor (the resin-filled section is omitted). [Figure 3] Figure 3 is a cross-sectional view taken along line AA in Figure 2. [Figure 4]FIG. 4 is an exploded perspective view showing the state of the same capacitor during manufacturing. [Figure 5] FIG. 5 is a perspective view showing the capacitor according to the second embodiment. [Figure 6] FIG. 6 is a plan view (omitting the resin filling part) showing the same capacitor. [Figure 7] FIG. 7 is a cross-sectional view taken along line B-B of FIG. 6. [Figure 8] FIG. 8 is an exploded perspective view showing the state of the same capacitor during manufacturing. [Figure 9] FIG. 9 is a perspective view showing the capacitor according to the third embodiment. [Figure 10] FIG. 10 is a plan view (omitting the resin filling part) showing the same capacitor. [Figure 11] FIG. 11 is a cross-sectional view taken along line C-C of FIG. 10. [Figure 12] FIG. 12 is an exploded perspective view showing the state of the same capacitor during manufacturing. [Figure 13] FIG. 13 is a perspective view showing the capacitor according to the fourth embodiment. [Figure 14] FIG. 14 is a perspective view showing the capacitor according to the fifth embodiment. [Figure 15] FIG. 15 is a block diagram showing the inverter according to the first embodiment. [Figure 16] FIG. 16 is a schematic configuration diagram showing the vehicle according to the first embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0014] 1. Overview As a result of intensive research to solve the problems of the case-molded capacitor of Patent Document 1, the present inventors have developed the following capacitor 1.

[0015] In other words, as shown in Figure 1, the capacitor 1 according to this embodiment comprises a capacitor element 2, a first busbar 41, a second busbar 42, a case 8, and a resin-filled portion 9. The capacitor element 2 has electrodes 3. The first busbar 41 has an element connection portion 6 and a first connecting portion 51. The element connection portion 6 is connected to the electrodes 3. The second busbar 42 has a second connecting portion 52 and an external terminal 71. The second connecting portion 52 is connected to the first connecting portion 51.

[0016] As shown in Figures 2 to 4, the case 8 has an opening 81, a bottom surface 82, and a side wall 83. The bottom surface 82 faces the opening 81. The side wall 83 extends from the bottom surface 82 to the opening 81. The case 8 houses the capacitor element 2 and the first busbar 41. A portion of the second busbar 42 is embedded in the case 8. The second connecting portion 52 is exposed inside the case 8 at a location closer to the opening 81 than to the bottom surface 82. The external terminal 71 is exposed outside the case 8 at a location closer to the bottom surface 82 than to the opening 81.

[0017] As shown in Figure 1, the resin-filled section 9 is filled inside the case 8. The connecting portion between the first connecting section 51 and the second connecting section 52 is located inside the resin-filled section 9.

[0018] As described above, the capacitor 1 according to this embodiment suppresses misalignment of the external terminals 71 relative to the case 8 without requiring complicated work. That is, since a part of the second busbar 42 is embedded in the case 8, misalignment of the external terminals 71 of the second busbar 42 can be suppressed when liquid curable resin is injected into the case 8. Furthermore, since the first connecting part 51 and the second connecting part 52 are connected before the liquid curable resin is injected into the case 8, there is no need for any work to fix the capacitor element 2 and the case 8.

[0019] Furthermore, according to the capacitor 1 of this embodiment, defects in the appearance of the external terminals 71 can also be suppressed. That is, the external terminals 71 are exposed to the outside of the case 8 from a point closer to the bottom surface 82 than to the opening 81. Therefore, when the liquid curable resin is injected into the case 8, it is suppressed that the liquid curable resin will crawl up the external terminals 71 or adhere to the external terminals 71.

[0020] Thus, according to the capacitor 1 of the first embodiment, misalignment of the external terminal 71 with respect to the case 8 is suppressed without requiring complicated work, and defects in the appearance of the external terminal 71 can also be suppressed.

[0021] Furthermore, since the connection portion between the first connecting portion 51 and the second connecting portion 52 is located within the resin-filled portion 9, connection reliability and insulation can be improved.

[0022] 2.Details (1) First Embodiment <Capacitor> Hereinafter, the capacitor 1 according to the first embodiment will be described with reference to Figures 1 to 4.

[0023] Each figure is a schematic representation, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. The arrows indicating directions in each figure are not intended to define the direction in which capacitor 1 is used, but are merely there to make the explanation easier to understand and do not represent any actual dimensions. In Figures 1 to 4, the up-down, left-right, and front-back directions are defined. These directions are orthogonal to each other. Viewing along the up-down direction is sometimes called a "plan view," viewing along the left-right direction is called a "side view," and viewing along the front-back direction is called a "front view." The same applies to Figures 5 to 14 described later.

[0024] As shown in Figures 1 to 4, the capacitor 1 according to the first embodiment comprises at least one capacitor element 2, at least one first busbar 41, at least one second busbar 42, a case 8, and a resin-filled portion 9.

[0025] Capacitor element The capacitor element 2 is not particularly limited, but examples include wound or multilayer film capacitor elements. The capacitor element 2 has a main body 20 and electrodes 3.

[0026] [Main body] The external shape of the main body 20 is not particularly limited, but in the first embodiment, the main body 20 has an oblate circular shape in front view and a rectangular shape in plan view and side view. Although not shown, a pair of internal electrodes face each other inside the main body 20 via a dielectric (e.g., a polymer film).

[0027] The material of the internal electrodes is not particularly limited, but examples include aluminum (Al), gold (Au), magnesium (Mg), zinc (Zn), tin (Sn), nickel (Ni), chromium (Cr), iron (Fe), copper (Cu), titanium (Ti), and alloys thereof.

[0028] The dielectric material is not particularly limited, but examples include polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polycarbonate (PC), and polystyrene (PS).

[0029] 〔electrode〕 The electrodes 3 are formed on both end faces (front and rear) of the main body 20, for example, by thermal spraying of metal. Thus, the capacitor element 2 has a pair of electrodes 3. The metal constituting the electrodes 3 is not particularly limited, but examples include zinc (Zn), tin (Sn), and alloys thereof.

[0030] Hereinafter, when distinguishing between the pair of electrodes 3, the electrode 3 formed on the front surface of the main body 20 will be referred to as the "first electrode 31," and the electrode 3 formed on the rear surface of the main body 20 will be referred to as the "second electrode 32" (see Figures 2 and 3).

[0031] 〔others〕 In the first embodiment, the capacitor 1 comprises four capacitor elements 2. The number of capacitor elements 2 in the capacitor 1 is not particularly limited.

[0032] The four capacitor elements 2 are arranged horizontally. That is, the four capacitor elements 2 are arranged so that the first electrode 31 and the second electrode 32 are aligned in the front-to-back direction.

[0033] The four capacitor elements 2 are arranged so that two are stacked vertically and two are side by side horizontally. When the capacitor 1 comprises multiple capacitor elements 2, the arrangement of the multiple capacitor elements 2 is not particularly limited.

[0034] ≪First Bus Bar≫ The first busbar 41 is a conductive member. The material of the first busbar 41 is not particularly limited, but examples include copper (Cu), aluminum (Al), and alloys thereof.

[0035] The first busbar 41 has at least one (four in the first embodiment) element connection portion 6 and a first connecting portion 51. The element connection portion 6 and the first connecting portion 51 are integrated. The first busbar 41 is formed, for example, by appropriately punching and bending a metal plate.

[0036] [Element connection section] The element connection part 6 is connected to the electrode 3. Specifically, the four element connection parts 6 are connected one-to-one to the electrodes 3 of the four capacitor elements 2. The connection between the element connection part 6 and the electrode 3 can be made, for example, by welding or soldering.

[0037] [1st connection part] The first connecting portion 51 is connected to the second connecting portion 52, as will be described later. In the first embodiment, the first connecting portion 51 protrudes in the front-rear direction from the upper part of the first bus bar 41.

[0038] 〔others〕 In the first embodiment, the capacitor 1 includes a pair of first busbars 41. The number of first busbars 41 included in the capacitor 1 is not particularly limited. The pair of first busbars 41 sandwich four capacitor elements 2 from the front and back.

[0039] Hereinafter, when distinguishing between the pair of first busbars 41, the first busbar 41 located at the front will be referred to as "first busbar 41a," and the first busbar 41 located at the rear will be referred to as "first busbar 41b." The element connection portion 6 and the first connecting portion 51 of the first busbar 41a will be referred to as "element connection portion 6a" and "first connecting portion 51a," respectively. The element connection portion 6 and the first connecting portion 51 of the first busbar 41b will be referred to as "element connection portion 6b" and "first connecting portion 51b," respectively.

[0040] As shown in Figures 2 and 3, each of the pair of first busbars 41 is connected one-to-one with each of the pair of electrodes 3. Specifically, the first busbar 41a is connected to the first electrode 31. More specifically, the four element connection points 6a of the first busbar 41a are connected one-to-one with the first electrodes 31 of the four capacitor elements 2. On the other hand, the first busbar 41b is connected to the second electrode 32. More specifically, the four element connection points 6b of the first busbar 41b are connected one-to-one with the second electrodes 32 of the four capacitor elements 2.

[0041] The first connecting portion 51a of the first bus bar 41a protrudes forward from the upper part of the first bus bar 41a. On the other hand, the first connecting portion 51b of the first bus bar 41b protrudes rearward from the upper part of the first bus bar 41b.

[0042] ≪Second Bus Bar≫ The second busbar 42 is also a conductive material, similar to the first busbar 41. Specific examples of the material for the second busbar 42 are the same as those for the first busbar 41.

[0043] The second busbar 42 has a second connecting portion 52, at least one (three in the first embodiment) external terminal 71, and at least one flat portion 72. The second connecting portion 52, the external terminal 71, and the flat portion 72 are integrated. Like the first busbar 41, the second busbar 42 is formed, for example, by appropriately punching and bending a metal plate. The second busbar 42 may further have at least one through hole 73.

[0044] [Second connection part] The second connecting portion 52 is connected to the first connecting portion 51. In the first embodiment, the second connecting portion 52 protrudes in the front-rear direction from the upper part of the second busbar 42. More specifically, as shown in Figure 2, the second connecting portion 52 has a surface facing outward through the opening 81 (a surface facing upward in the first embodiment). The first connecting portion 51 is positioned on the second connecting portion 52, but the arrangement of the two is not particularly limited. The connection between the first connecting portion 51 and the second connecting portion 52 can be made, for example, by welding or soldering. As described above, since the first connecting portion 51 can be positioned on the upward-facing surface of the second connecting portion 52, connection by welding or the like becomes easier.

[0045] [External terminals] The external terminal 71 is electrically connected to an external device (not shown). The external device is not particularly limited, but examples include components that make up the inverter 10. That is, the capacitor 1 can be part of the inverter 10, for example (see Figure 15 described later). In the first embodiment, the external terminal 71 extends downward.

[0046] [Plane part] The flat portion 72 is located between the second connecting portion 52 and the external terminal 71. As a result, when current flows between the second connecting portion 52 and the external terminal 71, current also flows through the flat portion 72.

[0047] [Through hole] The through-hole 73 has a different function and role than the through-hole formed in the external terminal 71 (see Figure 1). In other words, the through-hole 73 is located inside the case 8 itself.

[0048] 〔others〕 In the first embodiment, the capacitor 1 includes a pair of second busbars 42. The number of second busbars 42 provided by the capacitor is not particularly limited. The pair of second busbars 42 sandwiches a pair of first busbars 41 from the front and back.

[0049] Hereinafter, when distinguishing between the pair of second busbars 42, the second busbar 42 positioned at the front will be referred to as "second busbar 42a," and the second busbar 42 positioned at the rear will be referred to as "second busbar 42b." The second connecting portion 52, external terminal 71, and planar portion 72 of the second busbar 42a will be referred to as "second connecting portion 52a," "external terminal 71a," and "planar portion 72a," respectively. The second connecting portion 52, external terminal 71, and planar portion 72 of the second busbar 42b will be referred to as "second connecting portion 52b," "external terminal 71b," and "planar portion 72b," respectively.

[0050] The second connecting portion 52a of the second bus bar 42a protrudes forward from the upper part of the second bus bar 42a. On the other hand, the second connecting portion 52b of the second bus bar 42b protrudes rearward from the upper part of the second bus bar 42b.

[0051] As shown in Figures 2 and 3, a pair of second busbars 42 are connected one-to-one with a pair of first busbars 41. Specifically, the second busbar 42a is connected to the first busbar 41a. More specifically, the second connecting portion 52a of the second busbar 42a is connected to the first connecting portion 51a of the first busbar 41a. On the other hand, the second busbar 42b is connected to the first busbar 41b. More specifically, the second connecting portion 52b of the second busbar 42b is connected to the first connecting portion 51b of the first busbar 41b.

[0052] The second busbar 42a has three external terminals 71a. The second busbar 42b also has three external terminals 71b. In the first embodiment, the external terminals 71a and 71b are arranged alternately in the left-right direction. The number of external terminals 71 on the second busbar 42 is not particularly limited. The number of external terminals 71 can be increased or decreased depending on the application.

[0053] In the first embodiment, as shown in section D enclosed by the dashed line in Figure 3, the planar portion 72a of the second busbar 42a and the planar portion 72b of the second busbar 42b face each other. The narrower the distance between the opposing planar portions 72a and 72b, the better. Specifically, the distance between them is preferably 0.01 mm to 10 mm, more preferably 0.1 mm to 5 mm, and even more preferably 0.3 mm to 3 mm. The planar portions 72a and 72b extend in the left-right direction (the direction perpendicular to the plane of the paper in Figure 3).

[0054] ≪Case≫ Case 8 houses the capacitor elements 2 and the first busbars 41. In the first embodiment, case 8 houses four capacitor elements 2 and a pair of first busbars 41 (first busbar 41a and first busbar 41b).

[0055] The material for Case 8 is not particularly limited, but examples include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), epoxy resin (EP), etc.

[0056] A portion of the second busbar 42 is embedded in case 8. In the first embodiment, a portion of each of the pair of second busbars 42 (second busbar 42a and second busbar 42b) is embedded in case 8. However, the second connecting portion 52 and the external terminal 71 of the second busbar 42 are exposed from case 8.

[0057] The case 8 has an opening 81, a bottom portion 82, a side wall portion 83, at least one (two in the first embodiment) overhanging housing portion 84, and at least one (two in the first embodiment) protruding portion 85. The case 8 may further have at least one mounting portion 86.

[0058] [Opening] The opening 81 is located at the top of the case 8. Thus, the case 8 opens upwards.

[0059] [Bottom part] The bottom portion 82 faces the opening 81. A housing space 80 exists between the opening 81 and the bottom portion 82. The housing space 80 is the space in which the capacitor elements 2 and the first busbars 41 are housed. In the first embodiment, four capacitor elements 2 and a pair of first busbars 41 (first busbar 41a and first busbar 41b) are housed in the housing space 80.

[0060] Here, as shown in section D enclosed by the dashed line in Figure 3, at least a portion of each of the planar portions 72 of the pair of second busbars 42 are embedded in the case 8 and facing each other. Specifically, the planar portion 72a of the second busbar 42a and the planar portion 72b of the second busbar 42b are embedded in the bottom portion 82 of the case 8 and facing each other.

[0061] Furthermore, the external terminals 71 are exposed to the outside of the case 8 from a point closer to the bottom surface 82 than to the opening 81. Specifically, the external terminals 71 extend downward from the underside of the bottom surface 82.

[0062] [Side wall section] The side wall portion 83 extends from the bottom portion 82 to the opening 81. In the first embodiment, the side wall portion 83 forms a substantially rectangular frame shape in plan view (see Figure 2). Specifically, the side wall portion 83 has a front wall 831 and a rear wall 832 facing each other in the front-rear direction, and a left wall 833 and a right wall 834 facing each other in the left-right direction. The storage space 80 is surrounded by the side wall portion 83 and the bottom portion 82.

[0063] Here, the second bus bar 42 extends from the second connecting portion 52 through the interior of the side wall portion 83 itself to the external terminal 71 (see Figure 3). In this way, a part of the second bus bar 42 is embedded inside the case 8 itself. Specifically, the second bus bar 42a extends from the second connecting portion 52a through the interior of the front wall 831 itself to the external terminal 71a. On the other hand, the second bus bar 42b extends from the second connecting portion 52b through the interior of the rear wall 832 itself and the bottom portion 82 itself to the external terminal 71b.

[0064] In the first embodiment, the through-hole 73 of the second busbar 42 is located inside the side wall portion 83 itself (see Figure 3). The through-hole 73 may also be located inside the bottom portion 82 itself.

[0065] [Protruding storage area] The overhanging housing section 84 houses the connecting portion between the first connecting portion 51 and the second connecting portion 52. That is, as shown in Figures 2 and 3, the overhanging housing section 84 has an internal space 840, and the above-mentioned connecting portion is housed in this internal space 840.

[0066] The protruding storage section 84 extends outward from the side wall section 83 (front wall 831 and rear wall 832 in the first embodiment) from a point closer to the opening 81 than the bottom surface section 82 (see Figure 3). In other words, the protruding storage section 84 is formed by extending a part of the side wall section 83 outward. The protruding storage section 84 opens upward, and its internal space 840 faces the storage space 80. Thus, the internal space 840 of the protruding storage section 84 is in communication with the storage space 80.

[0067] In this specification, "inside case 8" and "inside case 8 itself" are distinguished. Specifically, "inside case 8" refers to the internal space 840 of the storage space 80 and the protruding storage section 84, while "inside case 8 itself" refers to the interior of the side wall section 83 itself and the interior of the bottom section 82 itself.

[0068] As described above, since the protruding storage section 84 protrudes outward from a point close to the opening 81, the second connecting section 52, which is housed in the internal space 840, is also exposed inside the case 8 at a point closer to the opening 81 than the bottom section 82. Specifically, the second connecting section 52a is exposed in the internal space 840 of the front protruding storage section 84. On the other hand, the second connecting section 52b is exposed in the internal space 840 of the rear protruding storage section 84.

[0069] [Protrusion] The protruding portion 85 is the part of the side wall portion 83 that protrudes outward (see Figure 1). In the first embodiment, the protruding portion 85 extends from directly below the overhanging housing portion 84 to the bottom surface portion 82. Since a part of the second bus bar 42 is embedded inside the case 8 itself, the protruding portion 85 protrudes outward. The thickness of the protruding portion 85 is greater than the thickness of the other side wall portion 83. The other side wall portion 83 is the part of the side wall portion 83 that does not protrude outward.

[0070] [Mounting part] The mounting portion 86 is used, for example, to attach the capacitor 1 to an external device (not shown). In the first embodiment, as shown in Figure 2, the mounting portion 86 has a metal collar 860, but the shape of the mounting portion 86 is not particularly limited. The mounting portion 86 protrudes outward from the side wall portion 83, but it may also protrude downward from the bottom surface of the bottom portion 82, and the arrangement of the mounting portion 86 is not particularly limited. The case 8 has three mounting portions 86, but the number of mounting portions 86 that the case 8 has is not particularly limited.

[0071] <<Resin-filled section>> The resin-filled section 9 is filled inside the case 8. That is, the resin-filled section 9 is filled inside the storage space 80 and the internal space 840 of the protruding storage section 84.

[0072] Since the capacitor element 2 and the first busbar 41 are housed in the housing space 80, they are located within the resin-filled section 9. Similarly, the connecting portion between the first connecting section 51 and the second connecting section 52 is housed in the internal space 840 of the protruding housing section 84, and is therefore located within the resin-filled section 9. In this way, the capacitor element 2, the first busbar 41, and the connecting portion between the first connecting section 51 and the second connecting section 52 are sealed by the resin-filled section 9.

[0073] The resin-filled portion 9 is formed from a cured liquid curable resin and has electrical insulating properties. The curable resin is not particularly limited, but examples include thermosetting resins and photocurable resins. Specifically, the curable resin is not particularly limited, but examples include epoxy resins.

[0074] The resin-filled portion 9 has an exposed surface 90. The exposed surface 90 is the surface that is exposed to the outside and is the upper surface. In the first embodiment, the capacitor element 2 and the first busbar 41 are located below the exposed surface 90. That is, the first busbar 41 is embedded in the resin-filled portion 9.

[0075] <Manufacturing method for capacitors> Next, a method for manufacturing the capacitor 1 according to the first embodiment will be described with reference to Figure 4.

[0076] First, prepare the capacitor element 2 to which the first busbar 41 is connected. Meanwhile, prepare the case 8 which is insert-molded using the second busbar 42.

[0077] Next, the capacitor element 2 is housed in the case 8, and the first connecting portion 51 of the first busbar 41 and the second connecting portion 52 of the second busbar 42 are connected.

[0078] Next, liquid curable resin is injected into the case 8 using a casting method and allowed to harden. This produces the capacitor 1 shown in Figure 1.

[0079] <Inverter> Next, the inverter 10 according to the first embodiment will be described with reference to Figure 15. The inverter 10 comprises a capacitor 1, a converter circuit 11, and an inverter circuit 12.

[0080] The converter circuit 11 is a circuit that converts alternating current to direct current and is electrically connected to the capacitor 1.

[0081] The inverter circuit 12 is a circuit that changes the voltage and / or frequency of the AC when converting DC to AC, and is electrically connected to the capacitor 1.

[0082] The inverter 10 is used, for example, as follows: The converter circuit 11 of the inverter 10 is connected to the power supply 13, and the inverter circuit 12 of the inverter 10 is connected to the motor 14. The power supply 13 and the motor 14 are included in the external equipment.

[0083] First, the AC power from the power supply 13 is converted to DC by the converter circuit 11 of the inverter 10, and the converted DC is then stabilized by the capacitor 1 through repeated charging and discharging. Next, this DC is converted back to AC at a desired voltage and frequency by the inverter circuit 12 of the inverter 10 and output.

[0084] <Vehicle> Next, the vehicle 100 according to the first embodiment will be described with reference to Figure 16. In particular, the drive system of the vehicle 100 will be described.

[0085] Vehicle 100 comprises an inverter 10, an AC motor 104, a transmission 105, a battery 107, an electronic control unit 108, wheels 101 (front wheels 102 and rear wheels 103), a front axle 106, and a rear axle (not shown). Vehicle 100 is an electric vehicle (EV) that runs using the AC motor 104 as its power source.

[0086] Vehicle 100 employs a front-wheel drive (FF) system. An AC motor 104, which serves as the drive source, and a transmission 105 are located at the front of the vehicle body. The transmission 105 changes the rotation of the AC motor 104 and transmits it to the front axle 106.

[0087] The front axle 106 is positioned horizontally in the vehicle width direction. Drive wheels, the front wheels 102, are attached to the left and right ends of the front axle 106. At the rear of the vehicle body, the rear axle (not shown) is positioned parallel to the front axle 106 and along the vehicle width direction. Rear wheels 103 are attached to the left and right ends of the rear axle.

[0088] Battery 107 is a DC power source. The DC power supplied from battery 107 is converted to AC power by inverter 10 and supplied to AC motor 104, which is then driven to rotate. The driving force (output) of AC motor 104 is controlled via inverter 10, which operates according to control signals output from electronic control unit 108.

[0089] <Effects and Effects> According to the capacitor 1 of the first embodiment, misalignment of the external terminals 71 relative to the case 8 is suppressed without requiring complicated work. That is, since a part of the second busbar 42 is embedded in the case 8, misalignment of the external terminals 71 of the second busbar 42 can be suppressed when liquid curable resin is injected into the case 8. Furthermore, since the first connecting part 51 and the second connecting part 52 are connected before the liquid curable resin is injected into the case 8, there is no particular need for work to fix the capacitor element 2 and the case 8.

[0090] Furthermore, according to the capacitor 1 of the first embodiment, defects in the appearance of the external terminals 71 can also be suppressed. That is, the external terminals 71 are exposed to the outside of the case 8 from a point closer to the bottom surface 82 than to the opening 81. Therefore, when the liquid curable resin is injected into the case 8, it is suppressed that the liquid curable resin will crawl up the external terminals 71 or adhere to the external terminals 71.

[0091] Thus, according to the capacitor 1 of the first embodiment, misalignment of the external terminal 71 with respect to the case 8 is suppressed without requiring complicated work, and defects in the appearance of the external terminal 71 can also be suppressed.

[0092] Furthermore, in the first embodiment, since the connecting portion between the first connecting portion 51 and the second connecting portion 52 is located within the resin-filled portion 9, connection reliability and insulation can be improved.

[0093] In the first embodiment, at least a portion of each of the planar portions 72 of the pair of second busbars 42 are embedded in the case 8 and face each other (see section D enclosed by the dashed line in Figure 3). Since currents flow in opposite directions through the opposing planar portions 72, the equivalent series inductance (ESL) can be reduced. Furthermore, since at least a portion of the planar portions 72 are embedded in the case 8, insulating plates and insulating paper are not required, and the number of components can be reduced.

[0094] Furthermore, in the first embodiment, the second busbar 42 extends through the inside of the side wall portion 83 itself to the external terminal 71. This eliminates the need to separately form a portion in the case 8 through which the second busbar 42 passes.

[0095] Furthermore, in the first embodiment, the case 8 has an overhanging housing section 84. The overhanging housing section 84 only needs to be formed where the connection between the first connecting section 51 and the second connecting section 52 exists, so there is no need to enlarge the entire case 8, and the weight of the capacitor 1 can be reduced. Moreover, since the overhanging housing section 84 is located close to the opening 81, the first connecting section 51 and the second connecting section 52 housed in the overhanging housing section 84 are also located close to the opening 81. Therefore, there is an advantage in that it is easy to connect the first connecting section 51 and the second connecting section 52 after housing the capacitor element 2 in the case 8. If the overhanging housing section 84 were located close to the bottom section 82, it would be difficult to connect the first connecting section 51 and the second connecting section 52, and the amount of liquid curable resin injected into the case 8 would increase by the amount that the overhanging housing section 84 extends vertically.

[0096] Furthermore, in the first embodiment, the case 8 has a protrusion 85. Since the protrusion 85 only needs to be formed in the area where a part of the second busbar 42 is embedded, it is not necessary to thicken the entire case 8, and the weight of the capacitor 1 can be reduced.

[0097] Furthermore, in the first embodiment, when forming the case 8 by insert molding, the resin used to form the case 8 is filled into the through-holes 73, thereby providing an anchoring effect and improving the adhesion between the second busbar 42 and the case 8. When forming through-holes 73 in two opposing planar portions 72, from the viewpoint of reducing the equivalent series inductance (ESL), it is preferable for the through-holes 73 to be as small as possible and for there to be as few through-holes 73 as possible. Therefore, the size and number of through-holes 73 are set appropriately in consideration of the effect of reducing the equivalent series inductance (ESL).

[0098] Furthermore, in the first embodiment, as shown in Figure 1, the first busbar 41 is embedded in the resin-filled portion 9. Therefore, the first busbar 41 can be prevented from being directly exposed to the outside air.

[0099] Furthermore, since the inverter 10 and vehicle 100 according to the first embodiment use the capacitor 1 described above, reliability can be improved.

[0100] (2) Second Embodiment <Capacitor> Next, the capacitor 1 according to the second embodiment will be described with reference to Figures 5 to 8. In the second embodiment, components similar to those in the first embodiment are given the same reference numerals as in the first embodiment, and detailed descriptions may be omitted. The following description will focus on the differences from the first embodiment.

[0101] In the second embodiment, the four capacitor elements 2 are arranged vertically. That is, the four capacitor elements 2 are arranged so that the second electrode 32 and the first electrode 31 are aligned vertically. The four capacitor elements 2 are arranged so that two are aligned horizontally and two are aligned front to back.

[0102] In the second embodiment, the case 8 has one protruding housing portion 84 and one protruding portion 85.

[0103] The protruding storage section 84 accommodates two connecting sections between the first connecting section 51 and the second connecting section 52 (see Figures 5 and 6). The two connecting sections are the connection between the first connecting section 51a and the second connecting section 52a, and the connection between the first connecting section 51b and the second connecting section 52b. The two connecting sections are aligned in the left-right direction.

[0104] The protruding portion 85 extends from directly below the overhanging housing portion 84 to the bottom portion 82. As shown in Figure 7, a part of the second bus bar 42 is embedded inside the protruding portion 85. Specifically, a part of each of the pair of second bus bars 42 (second bus bar 42a and second bus bar 42b) is embedded inside the protruding portion 85. More specifically, as shown in section E enclosed by the dashed line in Figure 7, the planar portion 72a of the second bus bar 42a and the planar portion 72b of the second bus bar 42b are facing each other while embedded in the protruding portion 85.

[0105] <Effects and Effects> The second embodiment also provides the same effects as the first embodiment. Furthermore, the second embodiment provides the following effects. That is, unlike the first embodiment, in the second embodiment, the two connecting portions are brought closer together and housed in a single overhanging housing portion 84, so that the planar portions 72 of the pair of second busbars 42 can more easily face each other inside the case 8 itself. Specifically, the area of ​​the opposing planar portions 72 is larger in the second embodiment (see portion E enclosed by the dashed line in Figure 7) than in the first embodiment (see portion D enclosed by the dashed line in Figure 3). Therefore, in the second embodiment, the equivalent series inductance (ESL) can be further reduced.

[0106] (3) Third Embodiment <Capacitor> Next, the capacitor 1 according to the third embodiment will be described with reference to Figures 9 to 12. In the third embodiment, components similar to those in the first and second embodiments are denoted by the same reference numerals as in the first and second embodiments, and detailed descriptions may be omitted. The following description will focus on the differences from the first and second embodiments.

[0107] The third embodiment differs from the second embodiment in that the case 8 does not have an overhanging storage section 84. Furthermore, the third embodiment is similar to the second embodiment in that the two connecting sections are aligned in the left-right direction, but differs from the second embodiment in that the first connecting section 51 and the second connecting section 52 protrude upward. Thus, in the third embodiment, as shown in Figures 10 and 11, the first connecting section 51 and the second connecting section are parallel to the side wall section 83, eliminating the need to form an overhanging storage section 84.

[0108] <Effects and Effects> The third embodiment also provides the same effects as the first embodiment. Furthermore, in the third embodiment, as in the second embodiment, the area of ​​the opposing planar portions 72 inside the case 8 itself is large (see section F enclosed by the dashed line in Figure 11). Therefore, in the third embodiment as well, the equivalent series inductance (ESL) can be further reduced.

[0109] Furthermore, in the third embodiment, unlike the second embodiment, there is no protruding housing portion 84, so the case 8 can be made slimmer than in the second embodiment. In other words, in the third embodiment, the capacitor 1 can be made slimmer.

[0110] (4) Fourth Embodiment <Capacitor> Next, the capacitor 1 according to the fourth embodiment will be described with reference to Figure 13. In the fourth embodiment, components similar to those in the first to third embodiments are denoted by the same reference numerals as in the first to third embodiments, and detailed descriptions may be omitted. The following description will focus on the differences from the first to third embodiments.

[0111] The fourth embodiment is similar to the first embodiment in that the four capacitor elements 2 are arranged horizontally. The fourth embodiment is also similar to the second embodiment in that the case 8 has one protruding housing portion 84 and one protruding portion 85.

[0112] The fourth embodiment differs from the first to third embodiments in terms of the position and orientation of the mounting portion 86 and the orientation in which the external terminal 71 extends. In the fourth embodiment, the external terminal 71 extends forward.

[0113] <Effects and Effects> The fourth embodiment also provides the same effects as the first and second embodiments. Furthermore, in the fourth embodiment, the capacitor 1 can be attached to an external device (not shown) in a different orientation than in the first to third embodiments.

[0114] (5) Fifth embodiment <Capacitor> Next, the capacitor 1 according to the fifth embodiment will be described with reference to Figure 14. In the fifth embodiment, components similar to those in the first to fourth embodiments are denoted by the same reference numerals as in the first to fourth embodiments, and detailed descriptions may be omitted. The following description will focus on the differences from the first to fourth embodiments.

[0115] The fifth embodiment differs from the third embodiment in that two of the six external terminals 71 extend upward. Specifically, two external terminals 71 extend upward from inside the case 8 beyond the opening 81. More specifically, external terminals 71a and 71b extend upward beyond the exposed surface 90 of the resin-filled portion 9.

[0116] <Effects and Effects> The fifth embodiment also produces the same effects as the first embodiment. Furthermore, in the fifth embodiment, The capacitor 1 can be attached to an external device (not shown) with the external terminal 71 facing a different orientation than that of the third embodiment.

[0117] As also stated in the section on [Problems to be Solved by the Invention], when the capacitor 1 has a plurality of external terminals 71, the objective of this disclosure is considered to have been achieved if cosmetic defects of at least some of the external terminals 71 can be suppressed. For example, in the capacitor 1 according to the fifth embodiment shown in Figure 14, even if cosmetic defects of the external terminals 71 extending upward cannot be suppressed, cosmetic defects of the external terminals 71 extending downward can be suppressed, so the objective of this disclosure is considered to have been achieved.

[0118] 3. Variant In the first to fifth embodiments, each of the first busbar 41 and the second busbar 42 is a pair (two), but each of the first busbar 41 and the second busbar 42 may be one or three or more.

[0119] In the first to fifth embodiments, the second busbar has a through hole 73, but it does not have to have a through hole 73.

[0120] In the first and fourth embodiments, the capacitor element 2 is arranged horizontally, but it may also be arranged vertically.

[0121] In the second, third, and fifth embodiments, the capacitor element 2 is arranged vertically, but it may also be arranged horizontally.

[0122] 4. Appearance As will be apparent from the above embodiments and modifications, this disclosure includes the following aspects. In the following, reference numerals are enclosed in parentheses solely to indicate their correspondence with the embodiments.

[0123] The first embodiment is a capacitor (1) comprising a capacitor element (2) having electrodes (3), a first busbar (41) having an element connection portion (6) connected to the electrodes (3) and a first connecting portion (51), a second busbar (42) having a second connecting portion (52) connected to the first connecting portion (51) and an external terminal (71), a case (8) having an opening (81), a bottom portion (82) facing the opening (81), and a side wall portion (83) extending from the bottom portion (82) to the opening (81), housing the capacitor element (2) and the first busbar (41), with a part of the second busbar (42) embedded in it, and a resin-filled portion (9) filled inside the case (8). The second connecting portion (52) is exposed inside the case (8) at a location closer to the opening (81) than the bottom portion (82). The external terminal (71) is exposed to the outside of the case (8) from a point on the side wall (83) that is closer to the bottom surface (82) than to the opening (81). The connection between the first connecting part (51) and the second connecting part (52) is located within the resin-filled part (9).

[0124] According to this embodiment, misalignment of the external terminal (71) relative to the case (8) is suppressed without requiring complicated work, and defects in the appearance of the external terminal (71) can also be suppressed. Furthermore, since the connecting portion between the first connecting portion (51) and the second connecting portion (52) is located within the resin-filled portion (9), connection reliability and insulation can be improved.

[0125] A second embodiment is a capacitor (1) comprising a capacitor element (2) having a pair of electrodes (3), a pair of first busbars (41; 41a, 41b) connected one-to-one with the pair of electrodes (3), a pair of second busbars (42; 42a, 42b) connected one-to-one with the pair of first busbars (41; 41a, 41b), a case (8) housing the capacitor element (2) and the pair of first busbars (41; 41a, 41b), with a portion of each of the pair of second busbars (42; 42a, 42b) embedded in it, and a resin-filled portion (9) filled inside the case (8). Each of the pair of first busbars (41; 41a, 41b) has an element connection portion (6) connected to one of the pair of electrodes (3) and a first connecting portion (51; 51a, 51b). Each of the pair of second busbars (42; 42a, 42b) has a second connecting portion (52; 52a, 52b) connected to a first connecting portion (51; 51a, 51b), an external terminal (71; 71a, 71b), and a flat portion (72; 72a, 72b) existing between the second connecting portion (52; 52a, 52b) and the external terminal (71; 71a, 71b). The case (8) has an opening (81), a bottom portion (82) facing the opening (81), and a side wall portion (83) extending from the bottom portion (82) to the opening (81). The external terminals (71; 71a, 71b) are exposed to the outside of the case (8) from a point on the side wall portion (83) that is closer to the bottom portion (82) than to the opening (81). At least a portion of each of the planar portions (72; 72a, 72b) of the pair of second busbars (42; 42a, 42b) are embedded in the case (8) and face each other.

[0126] According to this embodiment, misalignment of the external terminals (71; 71a, 71b) relative to the case (8) is suppressed without complicated work, and cosmetic defects of the external terminals (71; 71a, 71b) can also be suppressed. Furthermore, since at least a portion of the planar portions (72; 72a, 72b) of the pair of second busbars (42; 42a, 42b) are embedded in the case (8) and facing each other, the equivalent series inductance (ESL) can be reduced. Moreover, since at least a portion of the planar portions (72; 72a, 72b) are embedded in the case (8), insulating plates and insulating paper are unnecessary, and the number of parts can be reduced.

[0127] The third embodiment is a capacitor (1) based on the second embodiment. In the third embodiment, the second connecting portion (52; 52a, 52b) is exposed inside the case (8) at a location closer to the opening (81) than to the bottom portion (82). The connecting portion between the first connecting portion (51; 51a, 51b) and the second connecting portion (52; 52a, 52b) is located inside the resin-filled portion (9).

[0128] According to this embodiment, since the connection portion between the first connecting portion (51; 51a, 51b) and the second connecting portion (52; 52a, 52b) is located within the resin-filled portion (9), connection reliability and insulation can be improved.

[0129] The fourth embodiment is a capacitor (1) based on any one of the first to third embodiments. In the fourth embodiment, the second busbar (42) extends from the second connecting portion (52) through the inside of the side wall portion (83) itself to the external terminal (71).

[0130] According to this embodiment, since the second busbar (42) passes through the interior of the side wall portion (83) itself, it is not necessary to separately form a portion in the case (8) through which the second busbar (42) passes.

[0131] The fifth embodiment is a capacitor (1) based on any one of the first to fourth embodiments. In the fifth embodiment, the case (8) houses the connecting portion and further has an overhanging housing portion (84) that protrudes outward from a point on the side wall portion (83) that is closer to the opening (81) than the bottom portion (82).

[0132] According to this embodiment, since the case (8) further has an overhanging housing section (84), it is not necessary to enlarge the entire case (8), and the weight of the capacitor (1) can be reduced.

[0133] The sixth embodiment is a capacitor (1) based on any one of the first to fifth embodiments. In the sixth embodiment, the case (8) further has a protrusion (85) in which a part of the second busbar (42) is embedded and protrudes outward.

[0134] According to this embodiment, since the case (8) further has a protruding portion (85), it is not necessary to thicken the entire case (8), and the weight of the capacitor (1) can be reduced.

[0135] The seventh embodiment is a capacitor (1) based on any one of the first to sixth embodiments. In the seventh embodiment, the second busbar (42) further has a through hole (73) located inside the case (8) itself.

[0136] According to this embodiment, when forming the case (8) by insert molding, the resin for forming the case (8) is filled into the through hole (73), thereby improving the adhesion between the second busbar (42) and the case (8).

[0137] The eighth embodiment is a capacitor (1) based on any one of the first to seventh embodiments. In the eighth embodiment, the first busbar (41) is embedded in the resin-filled portion (9).

[0138] According to this embodiment, the first bus bar (41) can be prevented from being directly exposed to the outside air.

[0139] The ninth embodiment is an inverter (10) comprising a capacitor (1) based on any one of the first to eighth embodiments.

[0140] According to this embodiment, reliability can be improved.

[0141] The tenth embodiment is a vehicle (100) comprising an inverter (10) according to the ninth embodiment.

[0142] According to this embodiment, reliability can be improved. [Explanation of Symbols]

[0143] 1 Capacitor 2 Capacitor elements 3 electrodes 41 First Bus Bar 41a First bus bar 41b First bus bar 42 Second Bus Bar 42a Second bus bar 42b Second bus bar 51 1st connection part 51a 1st connection part 51b 1st connection part 52 2nd connection part 52a 2nd connection part 52b 2nd connection part 6. Element connection section 6a Element connection section 6b Element connection section 71 External terminals 71a External terminal 71b External terminal 72 Plane part 72a Flat part 72b Plane part 73 Through hole 73a Through hole 73b Through hole 8 cases 81 Opening 82 Bottom part 83 Side wall section 84. Projection storage section 85 Protrusion 9 Resin-filled section 10 Inverters 100 vehicles

Claims

1. A capacitor element having electrodes, A first busbar having an element connection portion connected to the electrode and a first connecting portion, A second busbar having a second connecting portion connected to the first connecting portion, and an external terminal, A case having an opening, a bottom portion facing the opening, and a side wall portion extending from the bottom portion to the opening, which houses the capacitor element and the first busbar, and in which a part of the second busbar is embedded, The case comprises a resin-filled section filled within the case, The second connecting portion is exposed inside the case at a location closer to the opening than the bottom portion. The external terminals are exposed to the outside of the case from a location closer to the bottom surface than the opening. The connecting portion between the first connecting portion and the second connecting portion is located within the resin-filled portion. Capacitor.

2. A capacitor element having a pair of electrodes, A pair of first busbars connected one-to-one with the pair of electrodes, A pair of second busbars connected one-to-one with the pair of first busbars, A case housing the capacitor element and the pair of first busbars, with a portion of each of the pair of second busbars embedded in it, The case comprises a resin-filled section filled within the case, Each of the pair of first busbars has an element connection portion connected to one of the pair of electrodes and a first connecting portion. Each of the pair of second busbars has a second connecting portion connected to the first connecting portion, an external terminal, and a flat portion located between the second connecting portion and the external terminal. The case has an opening, a bottom portion facing the opening, and a side wall portion extending from the bottom portion to the opening. The external terminals are exposed to the outside of the case from a location closer to the bottom surface than the opening. At least a portion of the planar portion of each of the pair of second busbars is embedded in the case and faces each other. Capacitor.

3. The second connecting portion is exposed inside the case at a location closer to the opening than the bottom portion. The connecting portion between the first connecting portion and the second connecting portion is located within the resin-filled portion. The capacitor according to claim 2.

4. The second busbar extends from the second connecting portion through the interior of the side wall portion itself to the external terminal. The capacitor according to claim 1.

5. The case further has an overhanging housing portion that houses the connecting portion and extends outward from a point on the side wall closer to the opening than the bottom surface portion. The capacitor according to claim 1.

6. The case further has a protruding portion into which a part of the second busbar is embedded and protrudes outward. The capacitor according to claim 1.

7. The second busbar further has a through hole located inside the case itself. The capacitor according to claim 1.

8. The first busbar is embedded in the resin-filled portion. The capacitor according to claim 1.

9. An inverter comprising a capacitor according to any one of claims 1 to 8.

10. A vehicle equipped with the inverter described in claim 9.

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