Capacitor

Abstract

The present invention achieves a capacitor capable of improving heat dissipation performance. This capacitor (1) comprises a plurality of capacitor elements (10), a housing (20), and a heat dissipation plate (30) formed of a metal having a higher thermal conductivity than the housing, the heat dissipation plate being joined to the housing.

Description

capacitor

[0001] The present invention relates to a capacitor.

[0002] Conventionally, capacitors have been known in which capacitor elements (electrodes and dielectrics) are housed in a metal housing, and the interior of the housing is filled with an insulator such as resin. In such capacitors, it is necessary to deal with the heat generated in the capacitor elements. Patent Document 1 discloses a configuration in which heat sinks are inserted between multiple capacitor elements, and the heat generated in the capacitor elements is dissipated by the heat sinks.

[0003] Japanese Patent Application Publication No. 2000-277377

[0004] However, in Patent Document 1, the heat sink is not directly connected to the housing, meaning that the contact between the heat sink and the housing is not good, leaving room for improvement in terms of heat dissipation.

[0005] Therefore, it is conceivable to improve the contact between the heat sink and the housing by welding the heat sink to the housing. However, when welding the heat sink to the housing, the heat sink must be made of the same metal as the housing to ensure good welding, and the heat sink cannot be made of a metal with a higher thermal conductivity than the housing. In other words, the heat dissipation performance of the heat sink is limited by the material of the housing. Therefore, there is room for further improvement in terms of heat dissipation performance.

[0006] An object of one aspect of the present invention is to provide a capacitor that can improve heat dissipation.

[0007] In order to solve the above problem, a capacitor according to one embodiment of the present invention comprises a plurality of capacitor elements, a housing that houses the plurality of capacitor elements, and a heat sink that is formed of a metal having a higher thermal conductivity than the housing and is arranged between the plurality of capacitor elements, and the heat sink is joined to the housing.

[0008] According to one aspect of the present invention, the heat dissipation performance of a capacitor can be improved.

[0009] The present invention will be described in detail with reference to the accompanying drawings, in which: Fig. 1 is a cross-sectional view showing a schematic configuration of a capacitor according to a first embodiment of the present invention; Fig. 2 is an enlarged cross-sectional view showing a detailed configuration of a fastening member in the capacitor; and Fig. 3 is an enlarged cross-sectional view showing a detailed configuration of a fastening member in the capacitor according to a second embodiment of the present invention.

[0010] [Embodiment 1] Hereinafter, an embodiment of the present invention will be described in detail. For the sake of convenience, components having the same functions as those shown in each embodiment will be denoted by the same reference numerals, and their description will be omitted as appropriate. Furthermore, directions are identified using X, Y, and Z shown in the drawings.

[0011] (Schematic Configuration of Capacitor 1) Fig. 1 is a cross-sectional view (cross-sectional view cut along the XY plane) showing the schematic configuration of a capacitor 1 according to one embodiment of the present invention. As shown in Fig. 1, capacitor 1 includes a plurality of capacitor elements 10, a housing 20, and a heat sink 30. In this embodiment, capacitor 1 is a metallized film capacitor.

[0012] The capacitor element 10 is an element portion that exhibits the electrical performance of a capacitor. In this embodiment, the capacitor element 10 is an element having a structure in which electrodes are wound around a winding core. Specifically, the capacitor element 10 has a structure in which two metallized films are stacked and wound around a winding core. The metallized film is formed by vapor-depositing a metal (electrode) as a surface electrode on one side of a dielectric substrate film. The capacitor element 10 has a substantially cylindrical shape and has a pair of electrodes 12 at both ends in the axial direction. The surface electrode of one metallized film is connected to one of the pair of electrodes 12, and the surface electrode of the other metallized film is connected to the other of the pair of electrodes 12.

[0013] The housing 20 houses a plurality of capacitor elements 10. The housing 20 has a substantially rectangular parallelepiped shape. Hereinafter, the direction perpendicular to the side surfaces extending in the longitudinal direction of the housing 20 will be referred to as the left-right direction (X-axis direction), the direction perpendicular to the side surfaces extending in the lateral direction of the housing 20 will be referred to as the front-rear direction (Y-axis direction), and the direction perpendicular to the XY plane will be referred to as the up-down direction (Z-axis direction). The dimensions of the housing 20 are, for example, approximately 600 mm in the front-rear direction, approximately 250 mm in the left-right direction, and approximately 800 mm in the up-down direction. The housing 20 may be made of any metal, such as stainless steel (SUS304, etc.).

[0014] The housing 20 includes a first side panel 21, a second side panel 22, a bottom panel 23 (not shown), and a top panel 24 (not shown). The housing 20 is constructed by welding the first side panel 21, the second side panel 22, the bottom panel 23, and the top panel 24 together.

[0015] The first side panel 21 and the second side panel 22 are welded together to form the side surfaces of the housing 20. The first side panel 21 is a flat plate member. The second side panel 22 has a fourth flat plate 221, a fifth flat plate 222 connected to the fourth flat plate 221, and a sixth flat plate 223 connected to the fourth flat plate 221 and facing the fifth flat plate 222.

[0016] The first side plate 21 and the second side plate 22 are welded together while being arranged to form at least a portion (in this embodiment, a side surface) of the housing 20. Specifically, one end of the first side plate 21 is welded to the end of the fifth flat plate 222, and the other end of the first side plate 21 is welded to the end of the sixth flat plate 223. As a result, the fifth flat plate 222 forms the first surface 20a of the housing 20 (located at the front end of the housing 20 in this embodiment), and the sixth flat plate 223 forms the second surface 20b (located at the rear end of the housing 20 in this embodiment) that faces the first surface 20a.

[0017] 1 , the fifth flat plate 222 is a flat plate extending from a first side of the fourth flat plate 221 in a direction perpendicular to the fourth flat plate 221. The sixth flat plate 223 is a flat plate extending from a second side opposite to the first side of the fourth flat plate 221 in a direction perpendicular to the fourth flat plate 221. In other words, the second side panel 22 has a U-shape.

[0018] The capacitor element 10, which has a substantially cylindrical shape, is arranged in the housing 20 with its axis aligned in the left-right direction. In the example shown in Fig. 1, two capacitor elements 10 are arranged in the left-right direction, and five capacitor elements 10 are arranged in the front-rear direction. Although not shown in Fig. 1, a plurality of capacitor elements 10 may be stacked in the vertical direction.

[0019] The electrodes 12 of the plurality of capacitor elements 10 are drawn out to the outside of the housing 20 by wiring. For example, the electrodes 12 of the plurality of capacitor elements 10 are connected in parallel to external terminals (not shown) outside the housing 20 by wiring. The external terminals function as terminals of the capacitor 1.

[0020] An insulator is filled between the housing 20 and the capacitor element 10. The insulator may be, for example, a resin such as an epoxy resin.

[0021] The heat sink 30 is provided at least inside the housing 20 so as to dissipate heat generated by the capacitor element 10. The heat sink 30 is formed of a material with a higher thermal conductivity than the housing 20. The heat sink 30 is formed of, for example, a metal. When the housing 20 is made of SUS, the heat sink 30 may contain, for example, aluminum or copper. The heat sink 30 is made of, for example, aluminum, an aluminum alloy (e.g., A5052), copper, or the like. The heat sink 30 may also contain a non-metallic material. When the housing 20 is made of SUS, the heat sink 30 may contain, for example, carbon, a highly thermally conductive resin, a highly thermally conductive ceramic, or the like.

[0022] The heat sink 30 is arranged so as to separate the space inside the housing 20. From the viewpoint of heat dissipation, it is preferable that the heat sink 30 is arranged inside the housing 20 so as to completely block the space between a pair of capacitor elements 10. However, it is sufficient that the heat sink 30 is located between at least a pair of capacitor elements 10. In other words, the two spaces separated by the heat sink 30 may be connected. In the example shown in FIG. 1 , the heat sink 30 extends in the front-to-rear direction so as to be located between the five capacitor elements 10 arranged on the left side and the five capacitor elements 10 arranged on the right side.

[0023] Specifically, the heat sink 30 is preferably provided inside the housing 20 so that one electrode 12 of the capacitor element 10 faces the heat sink 30. This allows the heat sink 30 to be provided near the electrode 12, which is particularly susceptible to heat generation in the capacitor element 10, and allows the heat generated in the capacitor element 10 to be efficiently dissipated. Furthermore, because the heat sink 30 faces the axial end face of the capacitor element 10, which is substantially cylindrical, the area in close proximity to the capacitor element 10 can be increased compared to when the heat sink 30 faces the side face of the capacitor element 10. In other words, the heat generated in the capacitor element 10 can be efficiently dissipated. The heat sink 30 preferably faces the entire axial end face of the capacitor element 10, but it is sufficient if it faces at least a portion of the axial end face of the capacitor element 10.

[0024] The heat sink 30 is joined to the housing 20. Specifically, the heat sink 30 is fastened to the housing 20 by at least one fastening member 40. The heat sink 30 has dimensions corresponding to the dimensions of the housing 20 so that, when fastened to the housing 20, the heat sink 30 extends from the front end to the rear end in the space inside the housing 20.

[0025] The heat sink 30 has a first flat plate 31, a second flat plate 32 connected to the first flat plate 31, and a third flat plate 33 connected to the first flat plate 31 and facing the second flat plate 32. Specifically, the second flat plate 32 extends from one end of the first flat plate 31 in a direction substantially perpendicular to the main surface of the second flat plate 32. The third flat plate 33 extends from the other end of the first flat plate 31 in a direction substantially perpendicular to the main surface of the second flat plate 32. In other words, the heat sink 30 has a U-shape. The heat sink 30 is formed, for example, by bending both ends of a single metal sheet into an L-shape.

[0026] The first flat plate 31 is a member that divides the space inside the housing 20. The first flat plate 31 is disposed between a plurality of capacitor elements 10. Specifically, the first flat plate 31 is located between the capacitor element 10 disposed on the left side and the capacitor element 10 disposed on the right side, and extends in the front-to-rear direction. The second flat plate 32 extends leftward while contacting the inner surface of the fifth flat plate 222 (the surface facing the interior of the housing 20). The third flat plate 33 extends leftward while contacting the inner surface of the sixth flat plate 223.

[0027] At least one fastening member 40 includes a first fastening member 401 and a second fastening member 402. The second flat plate 32 is joined to the first surface 20a of the housing (in this embodiment, the fifth flat plate 222) (fastened by the first fastening member 401). The third flat plate 33 is joined to the second surface 20b of the housing (in this embodiment, the sixth flat plate 223) opposite the first surface 20a (fastened by the second fastening member 402). In other words, the heat sink 30 is joined to the housing 20 on two opposing surfaces of the housing 20. This allows the heat sink 30 to be firmly joined to the housing 20. Note that the second flat plate 32 and the third flat plate 33 may each be fastened by a plurality of first fastening members 401 and a plurality of second fastening members 402 arranged in the vertical direction. Hereinafter, when there is no need to particularly distinguish between the first fastening member 401 and the second fastening member 402, they will be simply referred to as fastening members 40.

[0028] 2 is an enlarged cross-sectional view showing a detailed configuration of the fastening member 40. Below, a first fastening member 401 that fastens the fifth flat plate 222 and the second flat plate 32 together will be described as an example of the fastening member 40. Here, the second fastening member 402 that fastens the sixth flat plate 223 and the third flat plate 33 also has a similar configuration to the first fastening member 401, and therefore a description of the second fastening member 402 will be omitted.

[0029] 2, the fastening member 40 includes a bolt 41 and nuts 42 and 43. The fifth flat plate 222 of the housing 20 is provided with a through-hole 222a through which the bolt 41 passes. Similarly, the second flat plate 32 of the heat sink 30 is provided with a through-hole 32a through which the bolt 41 passes.

[0030] The shank of bolt 41 passes through through-hole 222a of fifth flat plate 222 and through-hole 32a of second flat plate 32 and extends into the interior of housing 20. Nuts 42 and 43 are fastened to the shank of bolt 41 on the more interior side of housing 20 than second flat plate 32. In this way, second flat plate 32 and fifth flat plate 222 are fastened together.

[0031] Furthermore, with the heat sink 30 fastened to the housing 20 by the fastening members 40, an adhesive 50 is applied between the housing 20 (the fifth flat plate 222) and the bolt 41. The adhesive 50 is applied between the housing 20 and the bolt 41 so as to seal the through-hole 222a formed in the housing 20. In the example shown in FIG. 2 , the adhesive 50 is applied to the through-hole 222a of the fifth flat plate 222. This ensures airtightness of the housing 20. Note that the position at which the adhesive 50 is applied is not limited to the position shown in FIG. 2 , and the adhesive 50 may be applied between the lower surface of the head of the bolt 41 and the upper surface of the fifth flat plate 222. The adhesive 50 may also be applied between the fifth flat plate 222 and the second flat plate 32, between the second flat plate 32 and the nut 42, and between the nut 42 and the shank of the bolt 41.

[0032] Furthermore, the second flat plate 32 and the fifth flat plate 222 are fastened together by two nuts 42, 43. This reduces loosening of the fastening member 40 over time.

[0033] Furthermore, the plurality of fastening members 40 are fastened to the housing 20 and the heat sink 30 so that the tightening torque of the bolts 41 in each of the plurality of fastening members 40 is a predetermined torque. This allows the plurality of fastening members 40 to be fastened to the housing 20 and the heat sink 30 so that no location has an insufficient tightening torque.

[0034] (Effects of Capacitor 1) One method for improving the heat dissipation of a capacitor is to weld a heat sink to the capacitor housing (hereinafter referred to as the welding method). However, with the welding method, the heat sink must be made of the same metal as the housing, and it is not possible to make the heat sink from a metal with a higher thermal conductivity than the housing. Therefore, there is room for further improvement in terms of heat dissipation.

[0035] On the other hand, in the capacitor 1 according to this embodiment, the heat sink 30 is fastened to the housing 20 by the fastening members 40. This allows the heat sink 30 to be made of a metal different from that of the housing 20. Therefore, by making the heat sink 30 of a metal with a higher thermal conductivity than the housing 20, the heat dissipation performance of the capacitor 1 can be improved.

[0036] Furthermore, in a capacitor, if a malfunction occurs in the capacitor element or the like, gas is generated inside the housing. If the housing is made airtight, the generation of such gas increases the internal pressure of the housing. Therefore, by monitoring the internal pressure of an airtight housing, malfunctions in the capacitor element or the like can be appropriately detected. The above-mentioned welding method is one possible method for ensuring the airtightness of the housing, but as mentioned above, there is room for further improvement in the welding method in terms of heat dissipation.

[0037] In the capacitor 1 according to this embodiment, a capacitor capable of improving heat dissipation is realized by fastening the housing 20 and the heat sink 30 with fastening members 40, and further, the airtightness of the housing 20 is ensured by applying adhesive 50 between the housing 20 and the bolts 41. In other words, a capacitor 1 is realized that can achieve both improved heat dissipation and appropriate detection of defects in the capacitor element 10.

[0038] (Example) The heat dissipation performance of the capacitors according to the comparative example and the example was verified by a thermal stability test. The capacitor according to the comparative example was a model simulating a capacitor including multiple capacitor elements, a stainless steel housing, and a stainless steel heat sink. The capacitor according to the example was a model simulating a capacitor including multiple capacitor elements, a stainless steel housing, and an aluminum heat sink fixed to the housing with bolts.

[0039] The thermal stability test was conducted under the following conditions. Specifically, the temperature inside the heating furnace used to heat the capacitors according to the comparative example and the example was 50±3°C. The test current was 846 A±3%. The test time was 48 hours. In the thermal stability test, the temperature was measured at six points inside the furnace (excluding the capacitor), four points on the surface of the housing, and nine points inside the housing (inside the winding core of the capacitor element).

[0040] As a result of the thermal stability test, a maximum temperature rise of 29°C was detected inside the housing of the capacitor according to the comparative example. On the other hand, a maximum temperature rise of 18.5°C was detected inside the housing of the capacitor according to the example. In other words, it can be seen that the temperature rise of the capacitor according to the example was improved by about 10°C compared to the capacitor according to the comparative example. A temperature rise improvement of 10°C can be said to be revolutionary in the technical field of such capacitors. This shows that by using an aluminum heat sink for the capacitor, a tremendous improvement in heat dissipation can be obtained.

[0041] [Embodiment 2] Another embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0042] Figure 3 is an enlarged cross-sectional view showing the detailed configuration of fastening member 40A in capacitor 1A. Reference numeral 3001 in Figure 3 is a transverse cross-sectional view of the location of fastening member 40A in capacitor 1A. Reference numeral 3002 in Figure 3 is an enlarged cross-section taken along cut plane A-A at reference numeral 3001 in Figure 3. Capacitor 1A differs from capacitor 1 in that it includes a housing 20A, a heat sink 30A, and a fastening member 40A instead of the housing 20, the heat sink 30, and the fastening member 40, respectively.

[0043] The housing 20A differs from the housing 20 in that it has a fifth flat plate 222A provided with a first stud bolt 222b, which is the first fastening member 401A, instead of the fifth flat plate 222 provided with the through hole 222a. The first stud bolt 222b extends from the inner surface of the fifth flat plate 222A toward the inside of the housing 20A.

[0044] Similarly, the housing 20A differs from the housing 20 in that instead of the sixth flat plate 223 having the through hole 223a, the housing 20A has a sixth flat plate 223A having the second stud bolt 223b, which is the second fastening member 402A.

[0045] The heat sink 30A differs from the heat sink 30 in that it has a second flat plate 32A with a notch 32b instead of the second flat plate 32 with the through hole 32a. A first stud bolt 222b is inserted into the notch 32b. The notch 32b is formed from the tip end of the second flat plate 32A toward the base end (right side).

[0046] Similarly, the heat sink 30A differs from the heat sink 30 in that it has a third flat plate 33A with a notch 33b instead of the third flat plate 33 with the through hole 33a. A second stud bolt 223b is inserted into the notch 33b.

[0047] The fastening member 40A differs from the fastening member 40 in that it includes the above-described first stud bolt 222b and second stud bolt 223b instead of the bolt 41. The fastening member 40A includes a first fastening member 401A and a second fastening member 402A that fasten the housing 20 and the heat sink 30 on two opposing surfaces (first surface 20a and second surface 20b) of the housing 20. The first fastening member 401A includes a first stud bolt 222b provided on the first surface 20a (fifth flat plate 222) of the housing 20. The first stud bolt 222b extends into the housing 20A through a notch 32b in the second flat plate 32A. The second fastening member 402A includes a second stud bolt 223b provided on the second surface 20b (sixth flat plate 223) of the housing 20. The second stud bolt 223b passes through the notch 33b of the third flat plate 33A and extends into the interior of the housing 20A.

[0048] (Operations and Effects of Capacitor 1A) The capacitor 1A according to this embodiment has the same effects as the capacitor 1.

[0049] Furthermore, the heat sink can be fastened to the housing 20A of the capacitor 1A without providing through holes for passing bolts through the housing 20A. This allows the capacitor 1A to have improved heat dissipation performance while ensuring the airtightness of the housing 20A.

[0050] The second flat plate 32A and the third flat plate 33A are provided with notches 32b and 33b, respectively. This allows the first stud bolt 222b and the second stud bolt 223b to be passed through the notches 32b and 33b by sliding the heat sink 30A to the left during installation, thereby facilitating the installation of the heat sink 30A to the housing 20A.

[0051] Furthermore, in capacitor 1A, unlike capacitor 1, the heads of bolts 41 of fastening members 40 do not protrude outside housing 20, so the area occupied by capacitor 1A is reduced and the appearance is improved.

[0052] (Modification) In the present embodiment, the configuration in which the heat sink 30 is joined to the housing 20 by the fastening members 40, 40A has been described. However, the configuration in which the heat sink 30 is joined to the housing 20 is not limited to this. For example, the housing 20 and the heat sink 30 may be joined together by an adhesive.

[0053] Alternatively, fastening member 40 may be provided on a first surface of the housing, and fastening member 40A may be provided on a second surface of the housing.

[0054] [Summary] A capacitor according to aspect 1 of the present invention comprises a plurality of capacitor elements, a housing that houses the plurality of capacitor elements, and a heat sink that is formed of a metal having a higher thermal conductivity than the housing and is arranged between the plurality of capacitor elements, and the heat sink is bonded to the housing.

[0055] According to the above configuration, the heat dissipation performance of the capacitor can be improved by forming the heat sink from a metal having a higher thermal conductivity than the housing.

[0056] In a capacitor according to Aspect 2 of the present invention, in the capacitor according to Aspect 1, the heat sink may be fastened to the housing by at least one fastening member.

[0057] According to the above configuration, the heat sink can be joined to the housing by the fastening member, which makes it possible to easily improve the contact of the heat sink with the housing, thereby improving the heat dissipation performance of the capacitor.

[0058] In a capacitor according to aspect 3 of the present invention, in the above-described aspect 2, the fastening member may include a bolt, the housing may have a through hole through which the bolt passes, and adhesive may be applied between the housing and the bolt when the heat sink is fastened to the housing by the fastening member.

[0059] According to the above configuration, the heat sink can be joined to the housing by inserting the shank of a bolt into the through-hole of the housing and the through-hole of the heat sink, and fastening it with a nut from the inside of the housing rather than the heat sink. In addition, by applying adhesive between the housing and the bolt, the airtightness of the housing can be ensured.

[0060] In a capacitor according to aspect 4 of the present invention, in any of aspects 1 to 3 above, the heat sink may have a first flat plate, a second flat plate connected to the first flat plate, and a third flat plate connected to the first flat plate and facing the second flat plate, and the second flat plate may be bonded to a first surface of the housing, and the third flat plate may be bonded to a second surface facing the first surface of the housing.

[0061] According to the above configuration, the heat sink can be firmly joined to the housing.

[0062] A capacitor according to Aspect 5 of the present invention may be configured as in Aspect 4 above, wherein the second flat plate is fastened to the first surface with a first fastening member, the third flat plate is fastened to the second surface with a second fastening member, the first fastening member includes a first stud bolt provided on the first surface, the second fastening member includes a second stud bolt provided on the second surface, and the second flat plate and the third flat plate may each have notches into which the first stud bolt and the second stud bolt are inserted.

[0063] According to the above configuration, the heat sink can be fastened to the housing without providing through holes in the housing for passing bolts, thereby realizing a capacitor with improved heat dissipation performance and ensuring airtightness of the housing.

[0064] The second and third flat plates each have a notch, which allows the first and second stud bolts to be passed through the notches in the second and third flat plates by sliding the heat sink during installation, facilitating the installation of the heat sink to the housing.

[0065] Furthermore, in the capacitor, the heads of the bolts do not protrude outside the housing, so the area occupied by the capacitor is small and the appearance is good.

[0066] A capacitor according to a sixth aspect of the present invention is the capacitor of any one of the first to fifth aspects, wherein an electrode of the capacitor element may face the heat sink.

[0067] According to the above configuration, the heat sink can be provided near the electrodes of the capacitor element, which are particularly prone to heat generation, and the heat generated in the capacitor element can be efficiently dissipated. Furthermore, because the heat sink faces the axial end face of the capacitor element, the area in which the heat sink is close to the capacitor element can be increased compared to when the heat sink faces the side face of the capacitor element. In other words, the heat generated in the capacitor element can be efficiently dissipated.

[0068] In the capacitor according to Aspect 7 of the present invention, in any one of Aspects 1 to 6, the housing may be stainless steel, and the heat sink may contain aluminum or copper.

[0069] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0070] REFERENCE SIGNS LIST 1, 1A Capacitor 10 Capacitor element 12 Electrode 20, 20A Housing 221 Fourth flat plate 222, 222A Fifth flat plate 222a Through hole in fifth flat plate (housing) 222b First stud bolt 223, 223A Sixth flat plate 223a Through hole in sixth flat plate (housing) 223b Second stud bolt 30, 30A Heat sink 31 First flat plate 32, 32A Second flat plate 32a Through hole in second flat plate 33, 33A Third flat plate 33a Through hole in third flat plate 40, 40A Fastening member 401, 401A First fastening member 402, 402A Second fastening member 41 Bolt 42, 43 Nut 50 Adhesive

Claims

1. A capacitor comprising: a plurality of capacitor elements; a housing that houses the plurality of capacitor elements; and a heat sink that is formed of a material having a higher thermal conductivity than the housing and is disposed between the plurality of capacitor elements, the heat sink being bonded to the housing.

2. The capacitor according to claim 1, wherein the heat sink is fastened to the housing by at least one fastening member.

3. The capacitor according to claim 2, wherein the fastening member includes a bolt, the housing has a through hole through which the bolt passes, and an adhesive is applied between the housing and the bolt with the heat sink fastened to the housing by the fastening member.

4. The capacitor described in claim 1, wherein the heat sink has a first flat plate, a second flat plate connected to the first flat plate, and a third flat plate connected to the first flat plate and facing the second flat plate, the second flat plate being bonded to a first surface of the housing, and the third flat plate being bonded to a second surface of the housing facing the first surface.

5. The capacitor described in claim 4, wherein the second flat plate is fastened to the first surface with a first fastening member, the third flat plate is fastened to the second surface with a second fastening member, the first fastening member includes a first stud bolt provided on the first surface, the second fastening member includes a second stud bolt provided on the second surface, and the second flat plate and the third flat plate respectively have notches into which the first stud bolt and the second stud bolt are inserted.

6. The capacitor according to claim 1, wherein an electrode of said capacitor element faces said heat sink.

7. The capacitor of any one of claims 1 to 6, wherein the housing is stainless steel and the heat sink comprises aluminum or copper.

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