Capacitor

Abstract

To provide a capacitor capable of improving heat dissipation from a capacitor element.SOLUTION: In the film capacitor, a plurality of capacitor elements 100 are arranged in two rows and disposed in a case such that a first electrode faces an opening of the case and a second electrode 120 faces a bottom surface portion of the case. Second bus bar 300 includes an overlapping part that is located between the opening of the case and the first electrode terminal part of the first bus bar in the filler resin and overlaps the first electrode terminal part, two electrode terminal parts 310 that are respectively connected to second electrodes 120 of capacitor elements 100 in two corresponding rows, and two first coupling parts 350 that sandwich the plurality of capacitor elements 100 from outside and connect the overlapping part and two electrode terminal parts 310.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a capacitor. [Background technology]

[0002] Conventionally, there has been known a case-molded capacitor in which a bus bar is connected to each electrode provided on both end faces of a capacitor element, the capacitor element to which the bus bars are connected is housed in a case, and the case is filled with a filling resin (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-103777 Summary of the Invention [Problem to be solved by the invention]

[0004] When a current is applied to the capacitor, the capacitor element generates heat. In the capacitor having the above configuration, the capacitor element is embedded in the filled resin, so heat is not easily released from the capacitor element.

[0005] In view of the above problem, an object of the present invention is to provide a capacitor that can improve heat dissipation from the capacitor element. [Means for solving the problem]

[0006] A first aspect of the present invention relates to a capacitor. The capacitor according to this aspect includes a plurality of capacitor elements each having a first electrode and a second electrode provided on each end surface, a first bus bar connected to the first electrodes, and a second bus bar connected to the second electrodes. A case having an opening on one side and accommodating the plurality of capacitor elements is provided, and a filling resin is filled into the case. The plurality of capacitor elements are arranged in two rows and are disposed within the case such that the first electrodes face the opening and the second electrodes face the bottom surface of the case. The first bus bar is located in the filling resin between the opening and the first electrodes and includes a first electrode terminal portion connected to the first electrodes. The second bus bar is located in the filling resin between the opening and the first electrode terminal portion and includes an overlapping portion that overlaps the first electrode terminal portion, two second electrode terminal portions that are respectively connected to the second electrodes of the capacitor elements in the two corresponding rows, and two relay portions that sandwich the plurality of capacitor elements from the outside and connect the overlapping portion and the two second electrode terminal portions.

[0007] A second aspect of the present invention relates to a capacitor. The capacitor according to this aspect includes a capacitor element having electrodes, a bus bar connected to the electrodes, a case having an opening on one side and housing the capacitor element, and a filled resin filled into the case. The bus bar includes an overlapping portion located in the filled resin between the opening and the capacitor element and overlapping the capacitor element, a first plate portion exposed from the filled resin and extending along the overlapping portion, a second plate portion extending from an end of the first plate portion toward the overlapping portion and connecting to the overlapping portion, and a support piece extending from the first plate portion toward the overlapping portion.

[0008] A third aspect of the present invention relates to a capacitor. The capacitor according to this aspect includes a capacitor element having electrodes, a bus bar connected to the electrodes, a case having an opening on one side and housing the capacitor element, and a filled resin filled in the case. The bus bar is positioned in the filled resin between the opening and the capacitor element. The capacitor further includes a heat transfer plate including an exposed surface exposed from the filled resin. The heat transfer plate has through holes, and the filled resin penetrates the through holes. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a capacitor that can improve heat dissipation from the capacitor element.

[0010] The effects and significance of the present invention will become more apparent from the following description of the embodiments, however, the embodiments shown below are merely examples of how the present invention can be put into practice, and the present invention is not limited to the embodiments described below. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1(a) is a perspective view of a film capacitor according to a first embodiment, and FIG. 1(b) is a perspective view of the film capacitor according to the first embodiment in a state where no filling resin is filled. [Figure 2] FIG. 2 is an exploded perspective view of the film capacitor according to the first embodiment. [Figure 3] FIG. 3 is a perspective view of the capacitor element unit according to the first embodiment, as viewed from below and behind. [Figure 4] FIG. 4(a) is a perspective view of a first bus bar according to the first embodiment, and FIG. 4(b) is a perspective view of a second bus bar according to the first embodiment. [Figure 5] FIG. 5(a) is a perspective view of a first insulating sheet according to the first embodiment, and FIG. 5(b) is a perspective view of a second insulating sheet. [Figure 6]FIG. 6(a) is a perspective view of a heat transfer plate according to the first embodiment, as viewed from below and in front, and FIG. 6(b) is a front cross-sectional view of the heat transfer plate according to the first embodiment. [Figure 7] FIG. 7(a) is a perspective view of a film capacitor according to the second embodiment, and FIG. 7(b) is a perspective view of a capacitor element unit according to the second embodiment. [Figure 8] FIG. 8(a) is a perspective view of a first bus bar according to the second embodiment, and FIG. 8(b) is a perspective view of a second bus bar according to the second embodiment. [Figure 9] FIG. 9 is a perspective view of a first insulating sheet according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] A film capacitor, which is one embodiment of a capacitor of the present invention, will be described below with reference to the drawings. For convenience, the front-rear, left-right, and up-down directions are indicated in each drawing as appropriate. Note that the directions shown in the drawings indicate only relative directions of the film capacitor, not absolute directions. For convenience of explanation, some components may be named according to the directions shown in the drawings, such as the "bottom portion" and the "front side portion."

[0013] First Embodiment A film capacitor 1A according to the first embodiment will be described.

[0014] FIG. 1(a) is a perspective view of the film capacitor 1A, and FIG. 1(b) is a perspective view of the film capacitor 1A in a state where the filling resin 600 is not filled.

[0015] 1(a) and 1(b), the film capacitor 1A includes four capacitor elements 100, a first bus bar 200, a second bus bar 300, a heat transfer plate 400, a case 500, and a filled resin 600. The four capacitor elements 100, the first bus bar 200, and the second bus bar 300 are integrally assembled to form a capacitor element unit 10. The capacitor element unit 10 is housed in the case 500, and the heat transfer plate 400 is placed on the second bus bar 300 of the capacitor element unit 10 via an insulating sheet 700. The case 500 is filled with a filled resin 600. The filled resin 600 is a thermosetting resin, for example, an epoxy resin. Within case 500, four capacitor elements 100 and portions of first bus bar 200 and second bus bar 300 are covered with hardened filling resin 600, and are protected from moisture and impact by case 500 and filling resin 600. The upper side of heat transfer plate 400 is exposed from filling resin 600.

[0016] Fig. 2 is an exploded perspective view of the film capacitor 1A. Fig. 3 is a perspective view of the capacitor element unit 10 as viewed from below and behind. Fig. 4(a) is a perspective view of the first bus bar 200, and Fig. 4(b) is a perspective view of the second bus bar 300. Fig. 5(a) is a perspective view of the first insulating sheet 810, and Fig. 5(b) is a perspective view of the second insulating sheet 820. For convenience, Fig. 2 shows by dashed lines installation regions R1 and R2 of the insulating sheet 700 and the heat transfer plate 400 on the second bus bar 300 of the capacitor element unit 10.

[0017] 2 to 5(b), capacitor element unit 10 includes four capacitor elements 100, a first bus bar 200, a second bus bar 300, a first insulating sheet 810, and a second insulating sheet 820.

[0018] The four capacitor elements 100 are formed by stacking two metallized films, each consisting of a dielectric film with aluminum vapor-deposited on it, and then rolling or laminating the stacked metallized films and pressing them flat. Each capacitor element 100 has a shape similar to a flat, elongated cylinder. A first electrode 110 is formed on one end face 101 of each capacitor element 100 by spraying a metal such as zinc, and a second electrode 120 is formed on the other end face 102 by spraying a metal such as zinc.

[0019] Although capacitor element 100 of the present embodiment is formed from a metallized film in which aluminum is vapor-deposited on a dielectric film, it may also be formed from a metallized film in which other metals such as zinc or magnesium are vapor-deposited. Alternatively, capacitor element 100 may be formed from a metallized film in which multiple metals selected from these metals are vapor-deposited, or from a metallized film in which an alloy of these metals is vapor-deposited.

[0020] In the capacitor element unit 10, the four capacitor elements 100 are arranged in two rows in the left-right direction, two by two, with one end face 101, i.e., the first electrode 110, facing upward and the other end face 102, i.e., the second electrode 120, facing downward, and with their peripheral faces 103 adjacent to each other. A first bus bar 200 and a second bus bar 300 are electrically connected to the first electrodes 110 and the second electrodes 120 of the four capacitor elements 100, respectively.

[0021] First bus bar 200 is formed into a predetermined shape by appropriately processing a plate-like conductive material, for example, a copper plate, such as by cutting or bending, and has a configuration in which electrode terminal portion 210, three first connection terminal portions 220, a second connection terminal portion 230, and a relay portion 240 are integrated together. In this embodiment, first bus bar 200 is a P-pole bus bar.

[0022] The electrode terminal portion 210 has a rectangular plate shape and contacts the first electrodes 110 of the four capacitor elements 100 so as to cover the first electrodes 110 from above. A total of four pairs of connection pins 211 are formed on the electrode terminal portion 210, one on the front side and one on the rear side of the left end and one on the front side and one on the rear side of the right end. A corresponding pair of connection pins 211 is joined to each first electrode 110 by a joining method such as soldering. In addition, a circular communication hole 212 is formed in the electrode terminal portion 210.

[0023] The electrode terminal portion 210 is connected to the three first connection terminal portions 220 and the three second connection terminal portions 230 by the relay portion 240. The relay portion 240 extends upward from the rear end of the electrode terminal portion 210 and is composed of a lower plate portion 241 having the same left-right width as the electrode terminal portion 210, and an upper plate portion 242 that protrudes more than the lower plate portion 241 on both the left and right sides.

[0024] The three first connection terminal portions 220 are provided on the upper end of the relay portion 240 so as to be aligned at equal intervals in the left-right direction. Each first connection terminal portion 220 has a hook shape that extends upward, then bends and extends rearward. A circular through-hole 221 is formed in each first connection terminal portion 220. A nut 222 is fitted into the through-hole 221.

[0025] The second connection terminal 230 is provided at the right end of the upper end of the relay part 240. The second connection terminal 230 has a shape that extends slightly upward, then bends and extends a long way rearward. The second connection terminal 230 has a circular through-hole 231 formed at its tip.

[0026] Second bus bar 300 is formed into a predetermined shape by appropriately processing a plate-like conductive material, for example, a copper plate, such as by cutting or bending, and has a configuration in which two electrode terminal portions 310, three first connection terminal portions 320, a second connection terminal portion 330, an overlapping portion 340, two first relay portions 350, and a second relay portion 360 are integrated together. In this embodiment, second bus bar 300 is an N-pole bus bar.

[0027] The left electrode terminal portion 310 has a rectangular plate shape with the front and rear corners on the left side cut at an angle, and comes into contact with the second electrodes 120 of the two capacitor elements 100 in the left column so as to cover the second electrodes 120 from below. The right electrode terminal portion 310 has a rectangular plate shape with the front and rear corners on the right side cut at an angle, and comes into contact with the second electrodes 120 of the two capacitor elements 100 in the right column so as to cover the second electrodes 120 from below.

[0028] The left electrode terminal 310 has a pair of connection pins 311 formed on the front and rear sides of its right end. The right electrode terminal 310 has a pair of connection pins 311 formed on the front and rear sides of its left end. The corresponding pair of connection pins 311 of the left electrode terminal 310 are joined to the second electrodes 120 of the two capacitor elements 100 in the left column by a joining method such as soldering. The corresponding pair of connection pins 311 of the right electrode terminal 310 are joined to the second electrodes 120 of the two capacitor elements 100 in the right column by a joining method such as soldering.

[0029] The overlapping portion 340 has a rectangular plate shape and overlaps the electrode terminal portion 210 of the first bus bar 200 from above. Two first relay portions 350 connect the two electrode terminal portions 310 and the overlapping portion 340. The left first relay portion 350 extends from the left electrode terminal portion 310 to pass outside (on the left side) of the row of left-side capacitor elements 100 and connects to the left end of the overlapping portion 340. The right first relay portion 350 extends from the right electrode terminal portion 310 to pass outside (on the right side) of the row of right-side capacitor elements 100 and connects to the right end of the overlapping portion 340. Circular communication holes 351 are formed in the two first relay portions 350 in portions that follow the circumferential surface 103 of the capacitor elements 100.

[0030] The overlapping portion 340 and the three first connection terminal portions 320 and the second connection terminal portion 330 are relayed by a second relay portion 360. The second relay portion 360 extends upward from the rear end of the overlapping portion 340 and is composed of a lower plate portion 361 having the same left-right width as the overlapping portion 340, and an upper plate portion 362 that protrudes more to the left and right than the lower plate portion 361. The second relay portion 360 overlaps the relay portion 240 of the first bus bar 200 from the front.

[0031] The three first connection terminal portions 320 are provided on the upper end portion of the second relay portion 360 so as to be aligned at equal intervals in the left-right direction. Each first connection terminal portion 320 is disposed to the left of the corresponding first connection terminal portion 220 of the first bus bar 200. The first connection terminal portion 320 has a hook shape that extends upward, then bends and extends rearward. A circular through hole 321 is formed in the first connection terminal portion 320. A nut 322 is fitted into the through hole 321.

[0032] The second connection terminal portion 330 is provided at the right end of the upper end portion of the second relay portion 360, and is lined up immediately to the right of the second connection terminal portion 230 of the first bus bar 200. The second connection terminal portion 330 has a shape that extends slightly upward and then bends and extends a long way rearward. A circular through-hole 331 is formed at the tip of the second connection terminal portion 330.

[0033] First insulating sheet 810 and second insulating sheet 820 are sandwiched between first bus bar 200 and second bus bar 300. First insulating sheet 810 and second insulating sheet 820 are formed from insulating paper or an insulating resin material such as acrylic or silicone.

[0034] The first insulating sheet 810 includes a first insulating portion 811, two second insulating portions 812, and a third insulating portion 813, each having a shape corresponding to the overlapping portion 340, the two first link portions 350, and the second link portion 360 of the second bus bar 300, respectively. The third insulating portion 813 covers both surfaces of the second link portion 360. The first insulating portion 811 is formed with a circular through hole 814 that overlaps with the through hole 212 of the electrode terminal portion 210 of the first bus bar 200. The two second insulating portions 812 are formed with semicircular notches 815 that overlap with the through hole 351 of the first link portion 350.

[0035] Second insulating sheet 820 has a shape corresponding to relay portion 240 of first bus bar 200 , and covers both surfaces of relay portion 240 .

[0036] The first insulating portion 811 is interposed between the electrode terminal portion 210 of the first bus bar 200 and the overlapping portion 340 of the second bus bar 300. This ensures insulation between the electrode terminal portion 210 and the overlapping portion 340. The overlapping portion 340 is close to the electrode terminal portion 210 via the first insulating portion 811. This makes it easier for heat to be conducted from the electrode terminal portion 210 to the overlapping portion 340. It is desirable that both the electrode terminal portion 210 and the overlapping portion 340 be in contact with the first insulating portion 811, but a small gap may be formed between the first insulating portion 811 and at least one of the electrode terminal portion 210 and the overlapping portion 340.

[0037] Two second insulating portions 812 are interposed between the first electrodes 110 of the four capacitor elements 100 and the two first relay portions 350 of the second bus bar 300. This ensures insulation between the first electrodes 110 of the four capacitor elements 100 and the two first relay portions 350.

[0038] Third insulating portion 813 and second insulating sheet 820 are interposed between relay portion 240 of first bus bar 200 and second relay portion 360 of second bus bar 300. This ensures insulation between relay portion 240 and second relay portion 360.

[0039] A highly thermally conductive insulating material may be used for first insulating sheet 810. In this case, the thermal conductivity of first insulating sheet 810 is set to, for example, about 3.0 to 3.5 W / m·K. This thermal conductivity is higher than the thermal conductivity of filling resin 600.

[0040] In the capacitor element unit 10, the electrode terminal portion 210 and relay portion 240 of the first bus bar 200 overlap with the overlapping portion 340 and second relay portion 360 of the second bus bar 300, which is expected to reduce the ESL (equivalent series inductance) in the capacitor element unit 10.

[0041] 6(a) is a perspective view of the heat transfer plate 400 as seen from below and in front, and FIG. 6(b) is a front cross-sectional view of the heat transfer plate 400. FIG.

[0042] 2, 6(a) and 6(b), heat transfer plate 400 is made of a metal material such as aluminum and is formed separately from second bus bar 300, and includes a first plate-shaped portion 410 and a second plate-shaped portion 420.

[0043] The first plate-shaped portion 410 has a rectangular flat plate shape. The upper surface of the first plate-shaped portion 410 is an exposed surface 401 that is exposed from the filling resin 600. The exposed surface 401 is flat. The first plate-shaped portion 410 has three circular through-holes 411 formed on each of the left and right sides. The upper end 411a of each through-hole 411 is chamfered, and the portion 411b below has a tapered shape in which the hole diameter gradually increases from the lower surface side to the upper surface side of the first plate-shaped portion 410. In addition, the first plate-shaped portion 410 has square recesses 412 formed on the left and right ends. The first plate-shaped portion 410 is larger in size than the second plate-shaped portion 420.

[0044] Second plate-shaped portion 420 has a rectangular shape, and is formed integrally with first plate-shaped portion 410 so as to protrude from the center of the lower surface of first plate-shaped portion 410. The lower surface of second plate-shaped portion 420 faces exposed surface 401 and serves as opposing surface 402 that faces the surface (upper surface) of overlapping portion 340 of second busbar 300.

[0045] 2, insulating sheet 700 is a sheet-like insulating member, has a rectangular shape, and is made of insulating paper or an insulating resin material such as acrylic or silicone. Insulating sheet 700 has a size larger than second plate-shaped portion 420 of heat transfer plate 400.

[0046] A highly thermally conductive insulating material may be used for insulating sheet 700. In this case, the thermal conductivity of insulating sheet 700 is set to, for example, about 3.0 to 3.5 W / m·K.

[0047] 2, case 500 is made of resin, for example, polyphenylene sulfide (PPS), which is a thermoplastic resin. Case 500 is formed in a substantially rectangular box shape and has bottom surface 501, front side surface 502, rear side surface 503, left side surface 504, and right side surface 505 rising from bottom surface 501, and has opening 506 on the top surface.

[0048] Case 500 is provided with first mounting tabs 510 at the corners between front side surface 502 and left side surface 504 and at the corners between front side surface 502 and right side surface 505. Circular mounting holes 511 are formed in first mounting tabs 510. Case 500 is also provided with second mounting tabs 520 at the front and rear sides of left side surface 504 and at the front and rear sides of right side surface 505. Circular mounting holes 521 are formed in second mounting tabs 520. Metal collars 522 are fitted into mounting holes 521 to reinforce the holes. Furthermore, the portions of left side surface 504 and right side surface 505 where rear second mounting tabs 520 are provided protrude inward in a shape that corresponds to recess 412 of heat transfer plate 400, forming protrusions 530.

[0049] 1(b), when the film capacitor 1A is assembled, the capacitor element unit 10 is housed in the case 500. The first electrodes 110 of the four capacitor elements 100 face the opening 506, and the second electrodes 120 face the bottom surface 501. The electrode terminal portions 210 of the first bus bar 200 are located between the opening 506 and each of the first electrodes 110, and the overlapping portions 340 of the second bus bar 300 are located between the opening 506 and the electrode terminal portions 210, overlapping the electrode terminal portions 210.

[0050] An insulating sheet 700 is placed on the overlapping portion 340 (installation region R1 in FIG. 2 ), and a heat transfer plate 400 is placed on top of that (installation region R2 in FIG. 2 ). The heat transfer plate 400 is located inside the case 500, closer to the opening 506 than the overlapping portion 340 so as to overlap the electrode terminal portion 210. The lower surface of the second plate-shaped portion 420 of the heat transfer plate 400 contacts the insulating sheet 700 and faces closely to the upper surface of the overlapping portion 340 as the opposing surface 402. The heat transfer plate 400 and the overlapping portion 340 are insulated from each other by the insulating sheet 700. The recessed portion 412 of the heat transfer plate 400 fits into the protruding portion 530 of the case 500, and the heat transfer plate 400 is positioned in the front-rear and left-right directions relative to the case 500. The upper surface of the heat transfer plate 400 protrudes slightly upward from the case 500.

[0051] Filling resin 600 in a liquid state is injected into case 500. At this time, filling resin 600 passes through communication hole 212 of first bus bar 200 and two communication holes 351 of second bus bar 300, which makes it easier for filling resin 600 to reach the four capacitor elements 100. When filling resin 600 fills case 500 up to the vicinity of opening 506, the injection of filling resin 600 is complete. Case 500 is heated, and filling resin 600 in case 500 hardens.

[0052] 1(a), film capacitor 1A is completed. In capacitor element unit 10, the three first connection terminal portions 220 and second connection terminal portion 230 of first bus bar 200 and the three first connection terminal portions 320 and second connection terminal portions 330 of second bus bar 300 are exposed from filled resin 600 and located at the rear of case 500. Also, a part of heat transfer plate 400, i.e., the upper side of first plate-shaped portion 410, is exposed from filled resin 600, and the upper surface of first plate-shaped portion 410 is exposed from filled resin 600 as exposed surface 401.

[0053] The six through holes 411 of the heat transfer plate 400 are filled partway with a filling resin 600. Because the through holes 411 are tapered, the filling resin 600 in the through holes 411 creates an anchor effect, making it difficult for the heat transfer plate 400 to come off upward.

[0054] The film capacitor 1A can be mounted, for example, in an inverter device for driving an electric motor in an electric vehicle. The inverter device receives DC power from a power supply (battery). The inverter device includes an inverter circuit including an IGBT (Insulated Gate Bipolar Transistor), converts the DC power into three-phase AC power, and supplies it to the electric motor.

[0055] Corresponding external terminals (not shown) connected to a power supply device are connected to second connection terminal portions 230 of first bus bar 200 and second connection terminal portions 330 of second bus bar 300 by screwing using through holes 231, 331. Corresponding external terminals (not shown) connected to an inverter circuit are connected to three first connection terminal portions 220 of first bus bar 200 and three first connection terminal portions 320 of second bus bar 300 by screwing using nuts 222, 322.

[0056] In order to enhance the heat dissipation effect, a cooling member 2 is attached to the exposed surface 401 of the heat transfer plate 400 of the film capacitor 1A installed in the inverter device, as shown by the dashed line in FIG. 1(a). The cooling member 2 is used to forcibly cool the heat transfer plate 400 from the outside, and is made of a material with excellent thermal conductivity, such as aluminum, and is configured with a flow path inside through which a refrigerant flows. The cooling member 2 may be a cooler using a Peltier element. Note that, since insulation is provided between the heat transfer plate 400 and the second bus bar 300 by an insulating sheet 700, the cooling member 2 directly contacts the exposed surface 401, on which it is attached.

[0057] When the inverter device operates and current is applied to the film capacitor 1A, the four capacitor elements 100 generate heat.

[0058] Heat generated from the four capacitor elements 100 is conducted to the electrode terminal portion 210 of the first bus bar 200, the two electrode terminal portions 310 of the second bus bar 300, and the two first relay portions 350. The heat transfer plate 400 is cooled by the cooling member 2. Therefore, the heat conducted to the two electrode terminal portions 310 and the two first relay portions 350 moves to the overlapping portion 340 and is conducted to the opposing surface 402 of the heat transfer plate 400, moves through the heat transfer plate 400 in its thickness direction, reaches the exposed surface 401, and is released from the exposed surface 401 to the cooling member 2. In addition, the overlapping portion 340 overlaps the electrode terminal portion 210 so as to be in close proximity to it. Therefore, the heat conducted to the electrode terminal portion 210 also moves to the overlapping portion 340, and further moves to the exposed surface 401 of the heat transfer plate 400, and is released from the exposed surface 401 to the cooling member 2.

[0059] Here, the heat transferred to the overlapping portion 340 moves in the thickness direction of the heat transfer plate 400, so the heat transfer path to the exposed surface 401 is short and has a large cross-sectional area. This reduces the thermal resistance of the transfer path, and heat is transferred well from the overlapping portion 340 to the exposed surface 401. This improves heat dissipation from the overlapping portion 340. Furthermore, because the first plate-shaped portion 410 of the heat transfer plate 400 is larger in size than the second plate-shaped portion 420, the area of ​​the exposed surface 401, which is the heat dissipation surface, is large, and the heat dissipation effect to the cooling member 2 is improved.

[0060] Furthermore, heat transferred to the left electrode terminal 310 is transferred to the overlapping portion 340 through the left first relay portion 350, and heat transferred to the right electrode terminal 310 is transferred to the overlapping portion 340 through the right first relay portion 350. In other words, the heat received by the electrode terminals 310 on both sides is transferred to the overlapping portion 340 via a short path, improving heat dissipation from the electrode terminals 310 on both sides.

[0061] In this way, heat is dissipated from the four capacitor elements 100 to the outside via the first bus bar 200, the second bus bar 300 and the heat transfer plate 400, so that the capacitor elements 100 are less likely to become hot when current is applied.

[0062] <Effects of the first embodiment> As described above, according to this embodiment, the following effects are achieved.

[0063] Film capacitor 1A includes capacitor element 100, first bus bar 200 and second bus bar 300 connected to first electrode 110 and second electrode 120, respectively, provided on both end faces 101 and 102 of capacitor element 100, case 500 having one open surface (top surface) and accommodating capacitor element 100, and filled resin 600 filled into case 500. First bus bar 200 includes a first portion (electrode terminal portion 210) that covers capacitor element 100 from the opening 506 side in filled resin 600, and second bus bar 300 includes a second portion (overlap portion 340) that overlaps the first portion from the opening 506 side in filled resin 600. The film capacitor 1A further includes a heat transfer portion (heat transfer plate 400) that is positioned closer to the opening 506 than the second portion so as to overlap the first portion, includes an exposed surface 401 exposed from the filling resin 600, and receives heat transferred to the second portion and releases it from the exposed surface 401.

[0064] With this configuration, by cooling the heat transfer section (heat transfer plate 400) from the outside, the heat transferred from capacitor element 100 to second bus bar 300 can be efficiently released to the outside through the heat transfer section, and the heat transferred to first bus bar 200 can be efficiently released to the outside through the second section (overlap section 340) and the heat transfer section. This makes it possible to improve heat dissipation from capacitor element 100 through first bus bar 200 and second bus bar 300, and to prevent capacitor element 100 from becoming too hot when current is applied.

[0065] Furthermore, the film capacitor 1A has a heat transfer portion (heat transfer plate 400) which is a plate-like member formed separately from the second bus bar 300, and is configured to include an opposing surface 402 which faces the exposed surface 401 and faces the surface of the second portion (overlap portion 340).

[0066] According to this configuration, the heat transferred to the second portion (overlap portion 340) moves in the thickness direction of the heat transfer portion (heat transfer plate 400), and the heat transfer path to exposed surface 401 is short and has a large cross-sectional area. This reduces the thermal resistance of the transfer path, and heat is transferred well from the second portion to exposed surface 401. This further improves heat dissipation from capacitor element 100 through first bus bar 200 and second bus bar 300.

[0067] Furthermore, the film capacitor 1A is configured such that the heat transfer portion (heat transfer plate 400) includes a first plate-shaped portion 410 having an exposed surface 401 and a second plate-shaped portion 420 integrally formed with the first plate-shaped portion 410 and having an opposing surface 402, and the first plate-shaped portion 410 is larger in size than the second plate-shaped portion 420.

[0068] According to this configuration, the area of ​​exposed surface 401, which is a heat dissipation surface, can be increased, and heat dissipation from exposed surface 401 can be improved.

[0069] Furthermore, the film capacitor 1A is configured such that the capacitor element 100 is arranged in the case 500 with the first electrode 110 facing the opening 506 and the second electrode 120 facing the bottom surface 501, the first bus bar 200 includes a first electrode terminal portion (electrode terminal portion 210) that covers the first electrode 110 and is connected to the first electrode 110, and the second bus bar 300 includes a second electrode terminal portion (electrode terminal portion 310) that covers the second electrode 120 and is connected to the second electrode 120, and a third portion (first relay portion 350) that extends from the second electrode terminal portion and connects to the second portion (overlap portion 340).

[0070] With this configuration, heat transferred from the capacitor element 100 to the second electrode terminal portion (electrode terminal portion 310) and the third portion (first relay portion 350) can be efficiently released to the outside through the second portion (overlapping portion 340) and the heat transfer portion (heat transfer plate 400), and heat transferred from the capacitor element 100 to the first electrode terminal portion (electrode terminal portion 210) can be efficiently released to the outside through the second portion (overlapping portion 340) and the heat transfer portion (heat transfer plate 400).

[0071] Furthermore, the film capacitor 1A is configured such that a plurality of (four) capacitor elements 100 are arranged in two rows within the case 500, and the second bus bar 300 includes two second electrode terminal portions (electrode terminal portions 310) that are respectively connected to the second electrodes 120 of the plurality of (two) capacitor elements 100 in each row, and two third portions (first relay portions 350) that extend from each second electrode terminal portion so as to pass outside each row and connect to the second portion (overlap portion 340) from opposite sides.

[0072] According to this configuration, heat received by the two second electrode terminals (electrode terminals 310) is transferred to the second portion (overlapped portion 340) over a short path, improving heat dissipation from the two second electrode terminals.

[0073] Furthermore, the film capacitor 1A is configured so that a cooling member 2 for cooling the heat transfer portion (heat transfer plate 400) is attached to the exposed surface 401.

[0074] According to this configuration, the heat transfer portion (heat transfer plate 400) can be cooled sufficiently, and the heat dissipation from first bus bar 200 and second bus bar 300 through the heat transfer portion can be improved sufficiently.

[0075] Second Embodiment A film capacitor 1B according to the second embodiment will be described.

[0076] Fig. 7(a) is a perspective view of film capacitor 1B, and Fig. 7(b) is a perspective view of capacitor element unit 10. Fig. 8(a) is a perspective view of first bus bar 200a, and Fig. 8(b) is a perspective view of second bus bar 300a. Fig. 9 is a perspective view of first insulating sheet 810a.

[0077] In the film capacitor 1A of the first embodiment, a heat transfer portion (heat transfer plate 400) is provided that is separate from the second bus bar 300. In contrast, in the film capacitor 1B of the second embodiment, the heat transfer portions (first heat transfer portion 370 and two second heat transfer portions 380) are integrally formed with the second bus bar 300.

[0078] In the film capacitor 1B, the capacitor element unit 10 includes a first bus bar 200a, a second bus bar 300a, and a first insulating sheet 810a having a configuration different from the first bus bar 200, the second bus bar 300, and the first insulating sheet 810 of the first embodiment described above, and does not include a second insulating sheet.

[0079] The first bus bar 200a is made of a conductive material and has a configuration in which an electrode terminal 210a, three first connection terminals 220a, a second connection terminal 230a, and a relay portion 240a are integrated together. The first bus bar 200a has a similar shape to the first bus bar 200 of the first embodiment, except that the electrode terminal 210a is longer in the front-rear direction than the electrode terminal 210 of the first embodiment and has a notch 213 at its front end. The electrode terminal 210a has four pairs of connection pins 211a and flow holes 212a. The three first connection terminals 220a have through holes 221a, and nuts 222a are attached to the through holes 221a. The second connection terminal 230a has a through hole 231a.

[0080] The second busbar 300a is formed from a conductive material and has a configuration in which two electrode terminal portions 310a, three first connection terminal portions 320a, a second connection terminal portion 330a, an overlapping portion 340a, two first relay portions 350a, a second relay portion 360a, a first heat transfer portion 370, and two second heat transfer portions 380 are integrated together.

[0081] The two electrode terminal portions 310a have a rectangular plate shape that is longer in the front-to-rear direction than the two electrode terminal portions 310 of the first embodiment. The left electrode terminal portion 310a has a pair of connection pins 311a formed on the front and rear sides of the right end, and a protruding piece 312 extending upward is formed at the rear end of the left end. The right electrode terminal portion 310a has a pair of connection pins 311a formed on the front and rear sides of the left end, and a protruding piece 312 extending upward is formed at the rear end of the right end.

[0082] The overlapping portion 340a includes a first overlapping portion 341 having the same shape as the overlapping portion 340 of the first embodiment, and a rectangular plate-like second overlapping portion 342 provided in front of the first overlapping portion 341 with the first heat transfer portion 370 sandwiched therebetween. The second overlapping portion 342 overlaps the front portion of the electrode terminal portion 210a of the first bus bar 200a from above. A circular circulation hole 343 is formed in the front portion of the first overlapping portion 341 to allow the filling resin 600 in a liquid phase to flow therethrough.

[0083] The three first connection terminal portions 320a, the second connection terminal portion 330a, the two first relay portions 350a, and the second relay portion 360a have shapes similar to the three first connection terminal portions 320, the second connection terminal portion 330, the two first relay portions 350, and the second relay portion 360 of the first embodiment. The two first relay portions 350a have flow holes 351a formed therein. The three first connection terminal portions 320a have through holes 321a formed therein, and nuts 322a are attached to the through holes 321a. The second connection terminal portion 330a has a through hole 331a formed therein.

[0084] The first heat transfer section 370 is provided in the front part of the overlapping section 340a, and the two second heat transfer sections 380 are provided on the left and right sides of the rear part of the overlapping section 340a.

[0085] The first heat transfer section 370 includes a first plate-shaped section 371 having a rectangular flat plate shape and two second plate-shaped sections 372. The front second plate-shaped section 372 extends from the front end of the first plate-shaped section 371 toward the second overlap section 342 and connects to the rear end of the second overlap section 342. The rear second plate-shaped section 372 extends from the rear end of the first plate-shaped section 371 toward the first overlap section 341 and connects to the front end of the first overlap section 341. Three oval circulation holes 373 are formed in each second plate-shaped section 372 to allow the filling resin 600 in a liquid phase to flow therethrough.

[0086] The two second heat transfer members 380 include a first plate-shaped member 381 and a second plate-shaped member 382 each having a rectangular flat plate shape. In the left second heat transfer member 380, the second plate-shaped member 382 extends from the left end of the first plate-shaped member 381 toward the first overlapping member 341 and connects to the left end of the first overlapping member 341. A support piece 383 extends from the right end of the first plate-shaped member 381 toward the first overlapping member 341 and abuts against the first overlapping member 341. The right side of the first plate-shaped member 381 is supported by the support piece 383. In the right second heat transfer member 380, the second plate-shaped member 382 extends from the right end of the first plate-shaped member 381 toward the first overlapping member 341 and connects to the right end of the first overlapping member 341. A support piece 383 extends from the left end of the first plate-shaped portion 381 toward the first overlapping portion 341 and abuts against the first overlapping portion 341. The left side of the first plate-shaped portion 381 is supported by the support piece 383.

[0087] The first insulating sheet 810a includes a first insulating portion 811a, two second insulating portions 812a, and a third insulating portion 813a, and has a shape similar to that of the first insulating sheet 810 of the first embodiment, except that the first insulating portion 811a is longer in the front-to-rear direction than the first insulating portion 811 of the first embodiment. A communication hole 814a is formed in the first insulating portion 811a, and notches 815a are formed in the two second insulating portions 812a. The first insulating sheet 810a ensures insulation between the second bus bar 300a and the first bus bar 200a and the first electrodes 110 of the four capacitor elements 100.

[0088] 7(a), within the case 500, the first heat transfer section 370 is located at the front, and the two second heat transfer sections 380 are located at the rear, side by side. The first plate-shaped section 371 of the first heat transfer section 370 and the first plate-shaped sections 381 of the two second heat transfer sections 380 extend along the opening 506 of the case 500, and are entirely exposed from the filled resin 600, so that their surfaces (upper surfaces) are exposed from the filled resin 600 as exposed surfaces 374, 384. The three exposed surfaces 374, 384 are all at the same height.

[0089] 7(a), the cooling member 2 is attached to the exposed surface 374 of the first heat transfer member 370 and the exposed surfaces 384 of the two second heat transfer members 380. At this time, an insulating sheet (not shown) similar to the insulating sheet 700 of the first embodiment is sandwiched between the cooling member 2 and the three exposed surfaces 374, 384, which are the attachment surfaces, thereby providing insulation between the second bus bar 300 and the cooling member 2.

[0090] When the inverter device operates and current is applied to the film capacitor 1B, the four capacitor elements 100 generate heat.

[0091] Heat generated from the four capacitor elements 100 is transferred to the electrode terminal 210a of the first bus bar 200a and the two electrode terminals 310a and two first relay portions 350a of the second bus bar 300a. The first heat transfer portion 370 and the two second heat transfer portions 380 are cooled by the cooling member 2. Therefore, the heat transferred to the two electrode terminals 310a and the two first relay portions 350a travels to the overlapping portion 340a and is transferred to the second plate-shaped portions 372 and 382 of the first heat transfer portion 370 and the two second heat transfer portions 380. The heat travels through these second plate-shaped portions 372 and 382 to reach the first plate-shaped portions 371 and 381, and is released from the exposed surfaces 374 and 384 to the cooling member 2. The overlapping portion 340a overlaps the electrode terminal 210a so as to be in close proximity to it. Therefore, the heat transferred to the electrode terminal portion 210a also moves to the overlap portion 340a, and then to the exposed surfaces 374, 384 of the first heat transfer portion 370 and the two second heat transfer portions 380, and is released from the exposed surfaces 374, 384 to the cooling member 2.

[0092] In this way, heat is dissipated from the four capacitor elements 100 to the outside via the first bus bar 200a, the second bus bar 300a and the heat transfer portions 370, 380, so that the capacitor elements 100 are less likely to become hot when current is applied.

[0093] <Effects of the second embodiment> In the film capacitor 1B of this embodiment, similarly to the first embodiment, by cooling the heat transfer sections (first heat transfer section 370, second heat transfer section 380) from the outside, heat transferred from the capacitor element 100 to the second bus bar 300a can be efficiently released to the outside through the heat transfer sections, and heat transferred to the first bus bar 200a can be efficiently released to the outside through the second section (overlap section 340a) and the heat transfer sections. This improves heat dissipation from the capacitor element 100 through the first bus bar 200a and the second bus bar 300a, and prevents the capacitor element 100 from becoming too hot when current is applied.

[0094] Furthermore, the film capacitor 1B is configured so that the heat transfer portions (first heat transfer portion 370, second heat transfer portion 380) are integrally formed with the second bus bar 300a, extend along the opening 506 of the case 500, and include first plate-shaped portions 371, 381 whose surfaces are exposed from the filled resin 600 as exposed surfaces 374, 384, and second plate-shaped portions 372, 382 that extend from the first plate-shaped portions 371, 381 toward the second portion (overlap portion 340a) of the second bus bar 300 and connect to the second portion.

[0095] According to this configuration, after the capacitor element unit 10 is housed in the case 500, there is no need to perform a separate operation of attaching a heat transfer portion to the case 500, which makes it easier to assemble the film capacitor 1B.

[0096] <Example of change> Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and application examples of the present invention can be modified in various ways in addition to the above-described embodiments.

[0097] For example, in the first embodiment described above, the insulating sheet 700 is interposed between the heat transfer plate 400 and the overlapping portion 340 of the second bus bar 300. However, a configuration may be adopted in which the insulating sheet 700 is not interposed between the heat transfer plate 400 and the overlapping portion 340, and the opposing surface 402 of the heat transfer plate 400 is in direct contact with the overlapping portion 340. In this case, when the cooling member 2 is attached to the exposed surface 401 of the heat transfer plate 400, the insulating sheet is sandwiched between the exposed surface 401 and the cooling member 2.

[0098] Furthermore, in the first embodiment, the heat transfer plate 400 is configured with the first plate-shaped portion 410 and the second plate-shaped portion 420, which are different in size. However, the heat transfer plate 400 may have any shape as long as it is configured as a plate-shaped member.

[0099] Furthermore, in the second embodiment, three heat transfer portions, namely, the first heat transfer portion 370 and two second heat transfer portions 380, are integrally formed with the second bus bar 300, but the number of heat transfer portions may be any number.

[0100] Furthermore, in the second embodiment, the first plate-shaped portions 371, 381 of the first heat transfer portion 370 and the two second heat transfer portions 380 are entirely exposed from the filled resin 600. However, as long as at least their surfaces (upper surfaces) are exposed as the exposed surfaces 374, 384, the first plate-shaped portions 371, 381 do not have to be entirely exposed from the filled resin 600.

[0101] Furthermore, in the first and second embodiments, first bus bars 200, 200a and second bus bars 300, 300a are provided with three first connection terminal portions 220, 320, 220a, 320a, but the number of first connection terminal portions 220, 320, 220a, 320a may be changed as appropriate. Furthermore, first bus bars 200, 200a and second bus bars 300, 300a may be provided with one type of connection terminal portion instead of two types of connection terminal portions, first connection terminal portions 220, 320, 220a, 320a and second connection terminal portions 230, 330, 230a, 330a.

[0102] Furthermore, in the first and second embodiments, the first bus bars 200, 200a are P-pole bus bars, and the second bus bars 300, 300a are N-pole bus bars. However, the first bus bars 200, 200a may be N-pole bus bars, and the second bus bars 300, 300a may be P-pole bus bars.

[0103] Furthermore, in the first and second embodiments, the capacitor elements 100 are arranged in two rows in the left-right direction, with a plurality of capacitor elements (two elements each) arranged in each row within the case 500. However, the capacitor elements 100 may be arranged in any manner within the case 500, and for example, a plurality of capacitor elements 100 may be arranged in a single row within the case 500. In this case, it is sufficient that the second bus bar 300, 300a is provided with one electrode terminal portion 310, 310a and one first relay portion 350, 350a.

[0104] Furthermore, in the first and second embodiments, the film capacitors 1A and 1B are provided with four capacitor elements 100. However, the number of capacitor elements 100 can be changed as appropriate, including the case where it is one.

[0105] Furthermore, in the first and second embodiments, capacitor element 100 is formed by stacking two metallized films with aluminum vapor-deposited on a dielectric film and then rolling or laminating the stacked metallized films. However, capacitor elements 100 may also be formed by stacking a metallized film with aluminum vapor-deposited on both sides of a dielectric film and an insulating film, and then rolling or laminating the resulting film.

[0106] Furthermore, in the first and second embodiments, the present invention is applied to film capacitors 1A and 1B in which capacitor element 100 is placed in case 500 so that first electrode 110 and second electrode 120 face opening 506 and bottom surface 501 of case 500. However, the present invention can also be applied to a film capacitor in which the capacitor element is placed in the case so that the first electrode and second electrode face the side surface of the case. In this case, the first bus bar has, for example, a first portion that covers the peripheral surface of the capacitor element from the opening side of the case as a relay portion between an electrode terminal portion connected to the first electrode and a connection terminal portion connected to an external terminal.

[0107] Furthermore, in the first and second embodiments, film capacitors 1A and 1B are given as examples of the capacitor of the present invention, but the present invention can also be applied to capacitors other than film capacitors.

[0108] In addition, the embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical ideas set forth in the claims.

[0109] In the description of the above embodiment, terms indicating directions such as "upper" and "lower" indicate relative directions that depend only on the relative positional relationship of the components, and do not indicate absolute directions such as vertical or horizontal. [Industrial Applicability]

[0110] The present invention is useful for capacitors used in various electronic devices, electrical devices, industrial devices, vehicle electrical equipment, and the like. [Explanation of symbols]

[0111] 1A film capacitor (capacitor) 2 Cooling material 100 capacitor element 110 1st electrode 120 2nd electrode 200 1st bus bar 210 Electrode terminal part (first electrode terminal part, first part) 300 2nd bus bar 310 Electrode terminal section (second electrode terminal section) 340 Polymerization part (second part) 350 First relay section (third section) 400 Heat transfer plate (heat transfer part) 401 Exposed surface 402 Opposite surface 410 First plate-shaped part 420 Second plate-shaped part 500 cases 501 Bottom part 506 Aperture 600 Filled Resin 1B film capacitor 200a 1st bus bar 210a Electrode terminal part (first electrode terminal part, first part) 300a 2nd bus bar 310a Electrode terminal part (second electrode terminal part) 340a Polymerization part (second part) 350a First relay section (third section) 370 First heat transfer section (heat transfer section) 371 First plate-shaped part 372 Second plate-shaped part 374 Exposed surface 380 First heat transfer section (heat transfer section) 381 First plate-shaped part 382 Second plate-shaped part 384 Exposed surface

Claims

1. a plurality of capacitor elements each having a first electrode and a second electrode provided on both end surfaces thereof; a first bus bar connected to the first electrode and a second bus bar connected to the second electrode; a case having an opening on one side and accommodating the plurality of capacitor elements; a filling resin filled in the case, the plurality of capacitor elements are arranged in two rows and are disposed in the case such that the first electrodes face the opening and the second electrodes face the bottom surface of the case; the first bus bar is located in the filled resin between the opening and the first electrode and includes a first electrode terminal portion connected to the first electrode; The second bus bar is an overlapping portion located in the filling resin between the opening and the first electrode terminal portion and overlapping the first electrode terminal portion; two second electrode terminal portions respectively connected to the second electrodes of the capacitor elements in the two corresponding columns; two relay portions that sandwich the plurality of capacitor elements from the outside and connect the overlapping portion and the two second electrode terminal portions, A capacitor characterized by:

2. a capacitor element having electrodes; a bus bar connected to the electrode; a case having an opening on one side and accommodating the capacitor element; a filling resin filled in the case, The bus bar is an overlapping portion located in the filling resin between the opening and the capacitor element and overlapping the capacitor element; a first plate-shaped portion exposed from the filled resin and extending along the overlapping portion; a second plate-shaped portion extending from an end of the first plate-shaped portion to the overlapping portion and connected to the overlapping portion; A support piece extending from the first plate-shaped portion toward the overlapping portion, A capacitor characterized by:

3. 3. The capacitor according to claim 2, The tip of the support piece is embedded in the filling resin. A capacitor characterized by:

4. a capacitor element having electrodes; a bus bar connected to the electrode; a case having an opening on one side and accommodating the capacitor element; a filling resin filled in the case, the bus bar is located in the filled resin between the opening and the capacitor element; a heat transfer plate including an exposed surface exposed from the filled resin; The heat transfer plate has a through hole, The filling resin has entered the through-hole. A capacitor characterized by:

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