Capacitor

Abstract

To provide a capacitor which can reduce variation in heat generated by a plurality of capacitor elements.SOLUTION: A capacitor 1 comprises: a plurality of capacitor elements 2 aligned in one direction; a first bus bar 31; and a second bus bar 32. Each of the plurality of capacitor elements 2 includes an element body 20, a first electrode 21, and a second electrode 22. The first bus bar 31 includes: a first internal terminal 41 connected to the first electrode 21; a first external terminal 51; and a first coupling part 61 which couples the first internal terminal 41 to the first external terminal 51. The first coupling part 61 includes a side plate 601 which is located on the lateral side of the plurality of capacitor elements 2. The second bus bar 32 includes: a second internal terminal 42 connected to the second electrode 22; a second external terminal 52; and a second coupling part 62 which couples the second internal terminal 42 to the second external terminal 52. The capacitor element 2 farthest from the first external terminal 51 is disposed at a position closest to the side plate 601 of the first coupling part 61.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates generally to capacitors, and more particularly to capacitors comprising multiple capacitor elements. [Background technology]

[0002] Patent Document 1 discloses a power conversion device that includes a plurality of semiconductor switching elements, a reactor, a low-voltage side capacitor, a high-voltage side capacitor, a charge / discharge capacitor, and a control unit that controls the drive of the plurality of semiconductor switching elements at a set drive frequency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-007325 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the power conversion device of Patent Document 1, the charge / discharge capacitor is configured by connecting multiple capacitor elements in parallel via first and second wiring, which poses a problem of the tendency for heat generation among the multiple capacitor elements to vary.

[0005] An object of the present disclosure is to provide a capacitor that can reduce variations in heat generation among a plurality of capacitor elements. [Means for solving the problem]

[0006] A capacitor according to one aspect of the present disclosure includes a plurality of capacitor elements arranged in one direction, a first bus bar, and a second bus bar. Each of the plurality of capacitor elements includes an element body, a first electrode provided at one end of the element body, and a second electrode provided at the other end of the element body. The first bus bar includes a first internal terminal connected to the first electrode, a first external terminal connected to an external device, and a first connecting portion connecting the first internal terminal to the first external terminal and extending in the direction in which the plurality of capacitor elements are arranged. The first connecting portion includes side plates located on both sides of the plurality of capacitor elements. The second bus bar includes a second internal terminal connected to the second electrode, a second external terminal connected to the external device, and a second connecting portion connecting the second internal terminal to the second external terminal. Of the plurality of capacitor elements, the capacitor element farthest from the first external terminal is located closest to the side plate of the first connecting portion. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to reduce variations in heat generation among a plurality of capacitor elements. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a capacitor according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the capacitor (excluding the case and the sealing portion). [Figure 3] FIG. 3 is an exploded perspective view showing the capacitor. [Figure 4] FIG. 4 is a plan view showing the capacitor of the same. [Figure 5] FIG. 5 is a bottom view showing the capacitor. [Figure 6] FIG. 6 is a perspective view showing a capacitor according to the second embodiment. [Figure 7] FIG. 7 is an exploded perspective view showing the capacitor. [Figure 8]FIG. 8 is a plan view showing the capacitor of the same. [Figure 9] FIG. 9 is a bottom view showing the capacitor. [Figure 10] FIG. 10 is a perspective view showing a capacitor according to the third embodiment. [Figure 11] FIG. 11 is an exploded perspective view showing the capacitor. [Figure 12] FIG. 12 is a plan view showing the capacitor of the same. [Figure 13] FIG. 13 is a bottom view showing the capacitor. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1. Overview As shown in FIGS. 1 to 5, a capacitor 1 according to this embodiment includes a plurality of capacitor elements 2 arranged in one direction (left-right direction), a first bus bar 31, and a second bus bar 32.

[0010] The distance (current path) between the capacitor element 2 and the first external terminal 51 of the first bus bar 31 varies depending on the position of the capacitor element 2. For example, the current path between the first capacitor element 2a and the first external terminal 51 is the longest, and the current path between the fourth capacitor element 2d and the first external terminal 51 is the shortest.

[0011] If the distance between the side plate 601 (see FIG. 3) of the first connecting portion 61 of the first bus bar 31 and the capacitor element 2 were uniform for all of the capacitor elements 2, there would be a risk of mismatch between the capacitance of each capacitor element 2 and the resonant frequency derived from the inductance in the current path of each capacitor element 2. As a result, variations in heat generation among the multiple capacitor elements 2 would be likely to occur.

[0012] Therefore, in this embodiment, of the multiple capacitor elements 2, the capacitor element 2 (first capacitor element 2a) that is farthest from the first external terminal 51 is arranged in a position closest to the side plate 601 of the first coupling portion 61. As a result, the magnetic flux generated by the current flowing through the first capacitor element 2a and the magnetic flux generated by the current flowing through the side plate 601 of the first coupling portion 61 cancel each other out. This makes it easier to match the inductance of the entire current paths of the multiple capacitor elements 2.

[0013] This makes it possible to match the capacitance of each capacitor element 2 with the resonant frequency derived from the inductance in the current path of each capacitor element 2. As a result, differences in impedance and phase are less likely to occur across the entire frequency range, making it possible to suppress variations in the currents that are shunted and flow through each capacitor element 2.

[0014] Therefore, according to this embodiment, the variation in heat generation among the plurality of capacitor elements 2 can be reduced.

[0015] 2.Details (1) First embodiment A capacitor 1 according to a first embodiment will be described below with reference to Figures 1 to 5. Each figure is a schematic diagram, and the ratios of the sizes and thicknesses of the components in each figure do not necessarily reflect the actual dimensional ratios.

[0016] The arrows indicating the various directions in each figure are not intended to define the directions in which the capacitor 1 should be used, but are merely used to make the explanation easier to understand, and have no substance.

[0017] The up-down direction is the direction connecting the first electrode 21 and the second electrode 22 of the capacitor element 2. The second electrode 22 side is referred to as the "top" and the first electrode 21 side is referred to as the "bottom." Viewing along the up-down direction is sometimes referred to as a "planar view."

[0018] The left-right direction is the direction in which the plurality of capacitor elements 2 are arranged. A view along the left-right direction is sometimes called a "side view."

[0019] The front-to-rear direction is the direction in which the capacitor element 2 and the side plate 601 of the first connecting portion 61 of the first bus bar 31 are aligned (see FIG. 4). The capacitor element 2 side is referred to as the "front" and the side plate 601 side is referred to as the "rear." Viewing along the front-to-rear direction is sometimes referred to as a "front view."

[0020] As shown in Fig. 2, the capacitor 1 according to the first embodiment includes a plurality of capacitor elements 2, a first bus bar 31, and a second bus bar 32. The capacitor 1 may further include an insulating member 7. As shown in Fig. 1, the capacitor 1 may further include a case 8 and a sealing portion 9. Each of the components will be described below in order.

[0021] <Capacitor element> A plurality of (four in this embodiment) capacitor elements 2 are arranged in one direction (left-right direction). When distinguishing between the four capacitor elements 2, these capacitor elements 2 may be referred to as a first capacitor element 2a, a second capacitor element 2b, a third capacitor element 2c, and a fourth capacitor element 2d, in that order from left to right.

[0022] The capacitor element 2 is a main component of the capacitor 1. There are no particular limitations on the capacitor element 2, but examples thereof include a wound capacitor element and a multilayer capacitor element.

[0023] Specifically, the capacitor element 2 includes an element body 20, a first electrode 21, and a second electrode 22.

[0024] <Element body> The element body 20 has a rounded rectangular shape in a plan view and a rectangular shape in a front view and a side view, but is not particularly limited to a shape of the element body 20. For example, the shape of the element body 20 may be a cylindrical shape, an elliptical cylindrical shape, a rectangular parallelepiped shape, or the like.

[0025] The element body 20 has a first end face 201, a second end face 202, and an outer peripheral surface 203. The first end face 201 is the bottom surface and has a rounded rectangular shape in a plan view (see FIG. 5). The second end face 202 is the top surface and, like the first end face 201, also has a rounded rectangular shape in a plan view (see FIG. 4). The outer peripheral surface 203 is a surface connecting the outer peripheral edge of the first end face 201 and the outer peripheral edge of the second end face 202 (see FIG. 2). The outer peripheral surface 203 has a flat surface 23 and a flat surface 24. The flat surface 23 is a flat surface facing left, and the flat surface 24 is a flat surface facing right (see FIGS. 4 and 5). Thus, the element body 20 includes two parallel flat surfaces 23, 24.

[0026] The element body 20 includes a dielectric film, a first internal electrode, and a second internal electrode. Inside the element body 20, the first internal electrode and the second internal electrode face each other via the dielectric film. The first internal electrode and the second internal electrode are vapor-deposited on the dielectric film. Thus, the capacitor 1 is a film capacitor. Note that the first internal electrode and the second internal electrode are not shown in the figure.

[0027] The material of the dielectric film is not particularly limited, but examples thereof include polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polycarbonate (PC), polystyrene (PS), etc. The outer peripheral surface 203 of the element body 20 may be formed of a dielectric film, but may also be formed of an electrically insulating member other than a dielectric film.

[0028] A portion of the first internal electrode is exposed at the first end surface 201 of the element body 20, but is not exposed at the second end surface 202. On the other hand, a portion of the second internal electrode is exposed at the second end surface 202 of the element body 20, but is not exposed at the first end surface 201. The material of the first internal electrode and the second internal electrode is not particularly limited, but examples thereof include aluminum (Al), gold (Au), magnesium (Mg), zinc (Zn), tin (Sn), nickel (Ni), chromium (Cr), iron (Fe), copper (Cu), titanium (Ti), and alloys thereof.

[0029] ≪First electrode≫ The first electrode 21 is provided at one end of the element body 20 (see FIG. 5). Specifically, the first electrode 21 is provided on a first end surface 201 of the element body 20.

[0030] The first electrode 21 is formed by spraying a metal onto the first end surface 201 of the element body 20. As a result, the first electrode 21 is electrically connected to the first internal electrode. The metal constituting the first electrode 21 is not particularly limited, but examples thereof include zinc (Zn), tin (Sn), and alloys thereof.

[0031] ≪Second electrode≫ The second electrode 22 is provided at the other end of the element body 20 (see FIG. 4). Specifically, the second electrode 22 is provided on a second end surface 202 of the element body 20.

[0032] The second electrode 22 is formed by spraying a metal onto the second end surface 202 of the element body 20. As a result, the second electrode 22 is electrically connected to the second internal electrode. The metal constituting the second electrode 22 is the same as the metal constituting the first electrode 21.

[0033] <First bus bar> First bus bar 31 is a conductive member. There are no particular limitations on the material of first bus bar 31, but examples thereof include copper (Cu), aluminum (Al), and alloys thereof.

[0034] 3, the first bus bar 31 includes a first internal terminal 41, a first external terminal 51, and a first connecting portion 61. The first internal terminal 41, the first external terminal 51, and the first connecting portion 61 are integrated together. The first bus bar 31 is formed, for example, by appropriately punching and bending a metal plate.

[0035] <<1st internal terminal>> The first internal terminals 41 correspond one-to-one to the capacitor elements 2. That is, the first bus bar 31 includes the same number of first internal terminals 41 as the capacitor elements 2. The first internal terminals 41 protrude forward from the first connecting portion 61. The first internal terminals 41 are connected to the first electrodes 21 by, for example, soldering (see FIG. 5).

[0036] <First external terminal> The first external terminal 51 is connected to an external device (not shown). The external device is not particularly limited, but may be, for example, a component that constitutes an inverter device. That is, the capacitor 1 may be, for example, a part of the inverter device.

[0037] The first external terminal 51 is disposed at a position closest to the fourth capacitor element 2d (see FIGS. 4 and 5). Furthermore, the first external terminal 51 is disposed at a position farthest from the first capacitor element 2a.

[0038] The first external terminal 51 is generally L-shaped in side view, that is, the first external terminal 51 protrudes upward from the first connecting portion 61 and then protrudes rearward.

[0039] <<1st connection part>> 3, the first coupling portion 61 couples the first internal terminal 41 and the first external terminal 51. The first coupling portion 61 extends in the direction in which the plurality of capacitor elements 2 are arranged (the left-right direction).

[0040] In this embodiment, the first connecting portion 61 is generally L-shaped in side view. Specifically, the first connecting portion 61 includes a side plate 601 and a bottom plate 611.

[0041] The side plates 601 are located on the sides (rearward in this embodiment) of the multiple capacitor elements 2. The side plates 601 are flat plates that have a thickness in the front-to-rear direction, a width in the up-down direction, and extend in the left-to-right direction. The width of the side plates 601 is approximately equal to the height (length in the up-down direction) of the capacitor elements 2. The length (left-to-right direction) of the side plates 601 is approximately equal to the product of the width (left-to-right direction) of the capacitor elements 2 and the number of capacitor elements 2 (four in this embodiment).

[0042] The first external terminal 51 protrudes upward from the upper end of the side plate 601 on the right side of the center in the left-right direction.

[0043] The bottom plate 611 is located below the multiple capacitor elements 2. The bottom plate 611 is a flat plate that has a thickness in the up-down direction, a width in the front-to-rear direction, and extends in the left-to-right direction. The width of the bottom plate 611 is approximately half the length (length in the front-to-rear direction) of the capacitor elements 2 (see FIG. 5). The length (left-to-right direction) of the bottom plate 611 is equal to the length (left-to-right direction) of the side plates 601.

[0044] The bottom plate 611 protrudes forward from the lower end of the side plate 601. A plurality of first internal terminals 41 protrude forward from the front end of the bottom plate 611.

[0045] <Second bus bar> The second bus bar 32 is also a conductive member like the first bus bar 31. The material of the second bus bar 32 is the same as the material of the first bus bar 31.

[0046] The second bus bar 32 is not in direct contact with the first bus bar 31. As shown in Fig. 3, the second bus bar 32 includes a second internal terminal 42, a second external terminal 52, and a second connecting portion 62. The second internal terminal 42, the second external terminal 52, and the second connecting portion 62 are integrated together. The second bus bar 32 is also formed, for example, by appropriately punching and bending a metal plate.

[0047] ≪Second internal terminal≫ The second internal terminals 42 correspond one-to-one to the capacitor elements 2. That is, the second bus bar 32 includes the same number of second internal terminals 42 as the capacitor elements 2. The second internal terminals 42 protrude forward from the second connecting portion 62. The second internal terminals 42 are connected to the second electrodes 22 by, for example, soldering (see FIGS. 2 and 4).

[0048] <Second external terminal> The second external terminal 52 is connected to an external device (not shown). Specific examples of the external device are as described above.

[0049] The second external terminal 52 is disposed to the left of the first external terminal 51 (see FIGS. 4 and 5). The second external terminal 52 is generally L-shaped in side view. That is, the second external terminal 52 protrudes upward from the second connecting portion 62 and then protrudes rearward.

[0050] ≪Second connection section≫ 3, the second connecting portion 62 connects the second internal terminal 42 and the second external terminal 52. The second connecting portion 62 extends in the direction in which the plurality of capacitor elements 2 are arranged (the left-right direction).

[0051] In this embodiment, the second connecting portion 62 includes a side plate 602. The side plate 602 is located on the side (rear in this embodiment) of the multiple capacitor elements 2. The side plate 602 has a thickness in the front-to-rear direction, a width in the up-down direction, and is a flat plate extending in the left-to-right direction. The width (up-down direction) and length (left-to-right direction) of the side plate 602 of the second connecting portion 62 are approximately equal to the width (up-down direction) and length (left-to-right direction) of the side plate 601 of the first connecting portion 61.

[0052] A plurality of second internal terminals 42 protrude forward from the upper end of the side plate 602. A second external terminal 52 protrudes upward from the upper end of the side plate 602 on the right side of the center in the left-right direction.

[0053] The side plates 602 are interposed between the plurality of capacitor elements 2 and the side plates 601 of the first connecting portion 61 in the front-rear direction. However, the side plates 602 of the second connecting portion 62 are not in direct contact with the side plates 601 of the first connecting portion 61.

[0054] The second connecting portion 62 has a plurality of through holes 60 (four in this embodiment). Specifically, the plurality of through holes 60 penetrate the side plate 602 in the front-to-rear direction. The through holes 60 correspond one-to-one to the capacitor elements 2. That is, the second connecting portion 62 has the same number of through holes 60 as the capacitor elements 2. When distinguishing between the four through holes 60, these through holes 60 may be referred to as a first through hole 60a, a second through hole 60b, a third through hole 60c, and a fourth through hole 60d, in that order from left to right.

[0055] <Insulating materials> The insulating member is a member having electrical insulation properties. The material of the insulating member 7 is not particularly limited, but examples thereof include polyphenylene sulfide (PPS).

[0056] The insulating member 7 is interposed between the side plate 601 of the first connecting portion 61 and the second connecting portion 62. Specifically, the insulating member 7 is interposed between the side plate 601 of the first connecting portion 61 and the side plate 602 of the second connecting portion 62 in the front-rear direction.

[0057] The insulating member 7 includes a main body portion 700 and a plurality of (four in this embodiment) positioning portions 70. The main body portion 700 and the plurality of positioning portions 70 are integrated together.

[0058] The main body 700 has a thickness in the front-rear direction, a width in the up-down direction, and a flat plate shape extending in the left-right direction. The width (up-down direction) and length (left-right direction) of the main body 700 are approximately equal to the width (up-down direction) and length (left-right direction) of the side plates 601. The side plates 601 of the first connecting portion 61 face the plurality of capacitor elements 2 via the main body 700 of the insulating member 7 and the side plates 602 of the second connecting portion 62.

[0059] The positioning portion 70 protrudes forward from the front surface of the main body portion 700. The positioning portion 70 passes through the through-hole 60 and abuts against the capacitor element 2 (see FIG. 4). In this way, the capacitor element 2 abuts against the tip of the positioning portion 70, thereby positioning the capacitor element 2 in the front-rear direction.

[0060] The positioning portions 70 correspond one-to-one to the through holes 60 of the second bus bar 32 and to the capacitor elements 2. That is, the insulating member 7 includes the same number of positioning portions 70 as the capacitor elements 2.

[0061] When distinguishing between the four positioning portions 70, these positioning portions 70 may be referred to as, from left to right, a first positioning portion 70a, a second positioning portion 70b, a third positioning portion 70c, and a fourth positioning portion 70d. The first positioning portion 70a, the second positioning portion 70b, the third positioning portion 70c, and the fourth positioning portion 70d correspond to the first through hole 60a, the second through hole 60b, the third through hole 60c, and the fourth through hole 60d, respectively. The first positioning portion 70a, the second positioning portion 70b, the third positioning portion 70c, and the fourth positioning portion 70d correspond to the first capacitor element 2a, the second capacitor element 2b, the third capacitor element 2c, and the fourth capacitor element 2d, respectively.

[0062] In this embodiment, when the four positioning portions 70 are arranged in order of shortest protruding length (front-rear direction), they are the first positioning portion 70a, the second positioning portion 70b, the third positioning portion 70c, and the fourth positioning portion 70d (see FIGS. 4 and 5). Note that the protruding lengths of the third positioning portion 70c and the fourth positioning portion 70d may be the same.

[0063] <Positional relationship of multiple capacitor elements> Next, the positional relationship between the plurality of capacitor elements 2 will be described.

[0064] The plurality of capacitor elements 2 are aligned in the left-right direction but are offset in the front-rear direction (see FIGS. 4 and 5). Note that the plurality of capacitor elements 2 are not offset in the up-down direction.

[0065] Specifically, of the multiple capacitor elements 2, the capacitor element 2 farthest from the first external terminal 51 is disposed in a position closest to the side plate 601 of the first coupling portion 61. Here, being farthest from the first external terminal 51 means that the current path to the first external terminal 51 is the longest. Also, being closest to the side plate 601 of the first coupling portion 61 means that the distance from the side plate 601 (the distance along the front-to-rear direction) is the shortest. Note that the distance from the side plate 601 can be adjusted by the protruding length (the length in the front-to-rear direction) of the positioning portion 70 of the insulating member 7.

[0066] That is, in this embodiment, of the four capacitor elements 2, the first capacitor element 2a which is farthest from the first external terminal 51 is disposed at a position closest to the side plate 601 of the first coupling portion 61.

[0067] Furthermore, of the multiple capacitor elements 2, the capacitor element 2 closest to the first external terminal 51 is disposed at a position farthest from the side plate 601 of the first connecting portion 61. Here, being closest to the first external terminal 51 means that the current path to the first external terminal 51 is the shortest. Furthermore, being farthest from the side plate 601 of the first connecting portion 61 means that the distance (distance along the front-to-rear direction) from the side plate 601 is the longest.

[0068] That is, in this embodiment, of the four capacitor elements 2, the fourth capacitor element 2d, which is closest to the first external terminal 51, is positioned at the farthest position from the side plate 601 of the first connecting portion 61 (see Figures 4 and 5).

[0069] Preferably, the shorter the distance between each of the plurality of capacitor elements 2 and the first external terminal 51, the longer the distance between each of the plurality of capacitor elements 2 and the side plate 601 of the first connecting portion 61. That is, in this embodiment, the distance (current path) between each of the plurality of capacitor elements 2 and the first external terminal 51 is shorter in the order of the first capacitor element 2a, the second capacitor element 2b, the third capacitor element 2c, and the fourth capacitor element 2d. Preferably, the distance (distance along the front-rear direction) between each of the plurality of capacitor elements 2 and the side plate 601 of the first connecting portion 61 is longer in the order of the first capacitor element 2a, the second capacitor element 2b, the third capacitor element 2c, and the fourth capacitor element 2d. Note that the distance between the third capacitor element 2c and the side plate 601 of the first connecting portion 61 and the distance between the fourth capacitor element 2d and the side plate 601 of the first connecting portion 61 may be the same.

[0070] Furthermore, in this embodiment, a plurality of capacitor elements 2 are arranged in one direction (left-right direction) with the flat surfaces 23, 24 facing each other (see FIGS. 4 and 5). That is, of two capacitor elements 2 adjacent to each other in the left-right direction, the flat surface 23 of one capacitor element 2 faces the flat surface 24 of the other capacitor element 2.

[0071] <Case> 1, the case 8 houses a plurality of capacitor elements 2. In this embodiment, the case 8 is open upward.

[0072] The case 8 has electrical insulation properties. The material of the case 8 is not particularly limited, but examples thereof include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), and epoxy resin (EP).

[0073] <Sealing part> As shown in FIG. 1 , the sealing portion 9 is filled into the case 8. Specifically, the sealing portion 9 fills the gap between the inner surface of the case 8 and the capacitor elements 2. Furthermore, except for the first external terminal 51 of the first bus bar 31, the second external terminal 52 of the second bus bar 32, and a portion of the insulating member 7, the plurality of capacitor elements 2, the first bus bar 31, the second bus bar 32, and the insulating member 7 are buried in the sealing portion 9. In this way, the sealing portion 9 seals the plurality of capacitor elements 2. The first external terminal 51 of the first bus bar 31 and the second external terminal 52 of the second bus bar 32 are drawn out from the sealing portion 9 to the outside.

[0074] The sealing portion 9 is a cured product of an electrically insulating resin. Examples of the resin include a thermosetting resin, a photocurable resin, etc. The resin is not particularly limited, but examples thereof include epoxy resin (EP).

[0075] <Action and effect> In the first embodiment, it is possible to reduce variations in heat generation among the plurality of capacitor elements 2. The reason for this is presumed to be as follows.

[0076] In this embodiment, among the multiple capacitor elements 2, the capacitor element 2 (first capacitor element 2a) farthest from the first external terminal 51 is positioned closest to the side plate 601 of the first connecting portion 61 (see Figures 4 and 5).

[0077] In this way, the first capacitor element 2a is disposed at the position farthest from the first external terminal 51, and therefore the inductance generated by the current path from the first external terminal 51 to the first capacitor element 2a is large. In this way, the longer the current path, the greater the inductance.

[0078] However, the first capacitor element 2a is disposed closest to the side plate 601 of the first coupling part 61. Therefore, the magnetic flux generated by the current flowing through the first capacitor element 2a and the magnetic flux generated by the current flowing through the side plate 601 of the first coupling part 61 cancel each other out. This cancellation of the magnetic fluxes has the effect of lowering inductance. Therefore, it becomes easier to match the inductance of the entire current paths of the four capacitor elements 2.

[0079] This makes it possible to match the capacitance of each capacitor element 2 with the resonant frequency derived from the inductance in the current path of each capacitor element 2. As a result, differences in impedance and phase are less likely to occur across the entire frequency range, making it possible to suppress variations in the currents that are shunted and flow through each capacitor element 2.

[0080] Therefore, according to this embodiment, the variation in heat generation among the plurality of capacitor elements 2 can be reduced.

[0081] Furthermore, in this embodiment, of the plurality of capacitor elements 2, the capacitor element 2 (fourth capacitor element 2d) closest to the first external terminal 51 is disposed at a position farthest from the side plate 601 of the first coupling portion 61. This makes it possible to further reduce the variation in heat generation among the plurality of capacitor elements 2.

[0082] Furthermore, it is preferable that the shorter the distance between each of the plurality of capacitor elements 2 and the first external terminal 51, the longer the distance between each of the plurality of capacitor elements 2 and the side plate 601 of the first coupling portion 61. This makes it possible to change the degree of cancellation of the magnetic fluxes described above depending on the magnitude of the inductance generated by the current path. Therefore, it is possible to match the inductance from the first external terminal 51 to the capacitor elements 2, and further reduce the variation in heat generation among the plurality of capacitor elements 2.

[0083] Furthermore, in this embodiment, the plurality of capacitor elements 2 are arranged in one direction (left-right direction) with the flat surfaces 23, 24 facing each other, which improves the fit of the plurality of capacitor elements 2. In other words, dead space is less likely to be formed between two adjacent capacitor elements 2.

[0084] In this embodiment, the insulating member 7 is interposed between the side plate 601 of the first connecting portion 61 and the second connecting portion 62. Specifically, the insulating member 7 is interposed between the side plate 601 and the side plate 602. This makes it possible to bring the side plate 601 and the side plate 602 closer to each other by adjusting the thickness of the insulating member 7 as needed, for example. This allows the inductance to be reduced.

[0085] 1, if capacitor 1 further includes case 8 and sealing portion 9, moisture resistance can be improved. That is, sealing portion 9 can prevent moisture from penetrating capacitor element 2.

[0086] (2) Second embodiment Next, a capacitor 1 according to a second embodiment will be described with reference to Figures 6 to 9. In the second embodiment, the same components as those in the first embodiment will be assigned the same reference numerals as in the first embodiment, and detailed description thereof may be omitted.

[0087] The second embodiment differs from the first embodiment in that the first external terminal 51 of the first bus bar 31 and the second external terminal 52 of the second bus bar 32 are disposed substantially in the center in the left-right direction.

[0088] <Positional relationship of multiple capacitor elements> In this embodiment as well, of the multiple capacitor elements 2, the capacitor element 2 closest to the first external terminal 51 is arranged in a position farthest from the side plate 601 of the first coupling portion 61. That is, in this embodiment, of the four capacitor elements 2, the third capacitor element 2c closest to the first external terminal 51 is arranged in a position farthest from the side plate 601 of the first coupling portion 61 (see FIGS. 8 and 9). That is, of the four positioning portions 70, the third positioning portion 70c has the longest protruding length.

[0089] Like the third capacitor element 2c, the second capacitor element 2b located to the left of the third capacitor element 2c may also be disposed at the position farthest from the side plate 601 of the first coupling portion 61. In other words, the protruding length of the second positioning portion 70b may be the same as the protruding length of the third positioning portion 70c.

[0090] Furthermore, of the multiple capacitor elements 2, the capacitor element 2 farthest from the first external terminal 51 is disposed in a position closest to the side plate 601 of the first connecting portion 61. That is, in this embodiment, of the four capacitor elements 2, the first capacitor element 2a which is farthest from the first external terminal 51 is disposed in a position closest to the side plate 601 of the first connecting portion 61. That is, of the four positioning portions 70, the protruding length of the first positioning portion 70a is the shortest.

[0091] Like the first capacitor element 2a, the fourth capacitor element 2d at the right end may also be disposed at a position closest to the side plate 601 of the first coupling portion 61. In other words, the protruding length of the fourth positioning portion 70d may be the same as the protruding length of the first positioning portion 70a.

[0092] <Action and effect> The second embodiment also achieves the same effects as the first embodiment. For this reason, the position of the first external terminal 51 of the first bus bar 31 in the left-right direction of the capacitor 1 is not limited. That is, the distance from the side plate 601 to each of the multiple capacitor elements 2 may be determined according to the position of the first external terminal 51 in the left-right direction (the length of the current path to the first external terminal 51).

[0093] (3) Third embodiment Next, a capacitor 1 according to a third embodiment will be described with reference to Figures 10 to 13. In the third embodiment, the same components as those in the first and second embodiments will be assigned the same reference numerals as those in the first and second embodiments, and detailed description thereof may be omitted.

[0094] The third embodiment differs from the second embodiment in that the second connecting portion 62 of the second bus bar 32 does not include the side plate 602.

[0095] ≪Second connection section≫ The second connecting portion 62 is generally L-shaped in side view and extends in the direction (left-right direction) in which the plurality of capacitor elements 2 are arranged. However, the second connecting portion 62 of this embodiment does not include the side plates 602 of the first and second embodiments. Therefore, the second connecting portion 62 of this embodiment does not have the through-holes 60 of the first and second embodiments.

[0096] The second connecting portion 62 of this embodiment is located above the plurality of capacitor elements 2, but is not located behind the plurality of capacitor elements 2. As a result, the side plate 601 of the first connecting portion 61 faces the plurality of capacitor elements 2 via the main body 700 of the insulating member 7.

[0097] <Action and effect> The third embodiment also provides the same advantageous effects as the first embodiment. In this way, even if the second connecting portion 62 of the second bus bar 32 does not include the side plate 602, the variation in heat generation among the plurality of capacitor elements 2 can be reduced.

[0098] 3. Variations In the first to third embodiments, the capacitor 1 includes four capacitor elements 2, but the number of capacitor elements 2 is not particularly limited as long as the capacitor 1 includes two or more capacitor elements 2.

[0099] Like the capacitor 1 according to the first embodiment, the capacitors 1 according to the second and third embodiments may also further include a case 8 and a sealing portion 9.

[0100] 4. Aspects As is clear from the above-described embodiments and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiments.

[0101] The first aspect is a capacitor (1) comprising a plurality of capacitor elements (2) arranged in one direction, a first bus bar (31), and a second bus bar (32). Each of the plurality of capacitor elements (2) includes an element body (20), a first electrode (21) provided at one end of the element body (20), and a second electrode (22) provided at the other end of the element body (20). The first bus bar (31) includes a first internal terminal (41) connected to the first electrode (21), a first external terminal (51) connected to an external device, and a first connecting portion (61) connecting the first internal terminal (41) and the first external terminal (51) and extending in the direction in which the plurality of capacitor elements (2) are arranged. The first connecting portion (61) includes a side plate (601) located on a side of the plurality of capacitor elements (2). The second bus bar (32) includes a second internal terminal (42) connected to the second electrode (22), a second external terminal (52) connected to the external device, and a second connecting portion (62) connecting the second internal terminal (42) and the second external terminal (52). Of the plurality of capacitor elements (2), the capacitor element (2; 2a) farthest from the first external terminal (51) is arranged at a position of the first connecting portion (61) closest to the side plate (601).

[0102] According to this aspect, it is possible to reduce variations in heat generation among the plurality of capacitor elements (2).

[0103] The second aspect is a capacitor (1) based on the first aspect. In the second aspect, of the plurality of capacitor elements (2), the capacitor element (2; 2d) closest to the first external terminal (51) is disposed at a position farthest from the side plate (601) of the first connecting portion (61).

[0104] According to this embodiment, the variation in heat generation among the plurality of capacitor elements (2) can be further reduced.

[0105] A third aspect is a capacitor (1) based on the first or second aspect. In the third aspect, the shorter the distance between each of the plurality of capacitor elements (2) and the first external terminal (51), the longer the distance between each of the plurality of capacitor elements (2) and the side plate (601) of the first connecting portion (61).

[0106] According to this embodiment, the variation in heat generation among the plurality of capacitor elements (2) can be further reduced.

[0107] A fourth aspect is a capacitor (1) based on any one of the first to third aspects. In the fourth aspect, the element body (20) includes two parallel flat surfaces (23, 24). The plurality of capacitor elements (2) are arranged in the one direction with the flat surfaces (23, 24) facing each other.

[0108] According to this embodiment, a plurality of capacitor elements (2) can be accommodated more easily.

[0109] A fifth aspect is a capacitor (1) based on any one of the first to fourth aspects, further comprising an insulating member (7) interposed between the side plate (601) of the first connecting portion (61) and the second connecting portion (62).

[0110] According to this aspect, the inductance can be reduced.

[0111] A sixth aspect is a capacitor (1) based on any one of the first to fifth aspects, further comprising a case (8) that houses the plurality of capacitor elements (2), and a sealing part (9) that seals the plurality of capacitor elements (2).

[0112] According to this aspect, it is possible to improve the moisture resistance. [Explanation of symbols]

[0113] 1 capacitor 2 Capacitor elements 20 Element body 21 1st electrode 22 2nd electrode 23 flat plane 24 flat plane 31 First bus bar 32 Second bus bar 41 1st internal terminal 42 2nd internal terminal 51 First external terminal 52 Second external terminal 61 1st connection part 601 Lateral plate 62 2nd connection part 7 Insulating material 8 cases 9 Sealing part

Claims

1. The capacitor includes a plurality of capacitor elements arranged in one direction, a first bus bar, and a second bus bar, Each of the plurality of capacitor elements includes an element body, a first electrode provided at one end of the element body, and a second electrode provided at the other end of the element body, the first bus bar includes a first internal terminal connected to the first electrode, a first external terminal connected to an external device, and a first coupling portion that couples the first internal terminal and the first external terminal and extends in a direction in which the plurality of capacitor elements are arranged, the first connecting portion includes a side plate located on a side of the plurality of capacitor elements, the second bus bar includes a second internal terminal connected to the second electrode, a second external terminal connected to the external device, and a second connecting portion connecting the second internal terminal and the second external terminal, Among the plurality of capacitor elements, the capacitor element farthest from the first external terminal is disposed at a position closest to the side plate of the first connecting portion. Capacitor.

2. Among the plurality of capacitor elements, the capacitor element closest to the first external terminal is disposed at a position farthest from the side plate of the first connecting portion. The capacitor of claim 1 .

3. the shorter the distance between each of the plurality of capacitor elements and the first external terminal, the longer the distance between each of the plurality of capacitor elements and the side plate of the first connecting portion; The capacitor according to claim 2 .

4. The element body includes two parallel flat surfaces, The plurality of capacitor elements are arranged in the one direction with the flat surfaces facing each other. The capacitor of claim 1 .

5. an insulating member interposed between the side plate of the first connecting portion and the second connecting portion; The capacitor of claim 1 .

6. The capacitor device further includes a case that houses the plurality of capacitor elements and a sealing portion that seals the plurality of capacitor elements. The capacitor of claim 1 .

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