Film capacitor

Abstract

To provide a film capacitor that can suppress resonance in the capacitor element. [Solution] The film capacitor 1 comprises a capacitor element 2 including a dielectric film 20 and a pair of metal films 21 facing each other across the dielectric film 20, a busbar 3 connected to the capacitor element 2, and a sealed case 4 having a housing space 40 larger than the capacitor element 2, in which the capacitor element 2 is housed and the busbar 3 is fixed. The capacitor element 2 is bonded to the inner surface 400 of the sealed case 4, either directly or indirectly via the busbar 3.

Description

Technical Field

[0001] The present disclosure generally relates to film capacitors, and more particularly to film capacitors provided with capacitor elements.

Background Art

[0002] Patent Document 1 discloses a capacitor. This capacitor includes a capacitor element having a first electrode on one end face and a second electrode on the other end face, and an exterior body that covers the entire capacitor element.

[0003] The exterior body has a first end face facing the first electrode and includes a first exterior body that covers the first electrode side of the capacitor element, and a second end face facing the second electrode and includes a second exterior body that covers the second electrode side of the capacitor element. The first exterior body and the second exterior body are joined so that the inside of the exterior body is in an airtight state.

[0004] A first bus bar is fixed inside the first end face of the first exterior body. The first bus bar contacts the first electrode and its tip extends outside the exterior body. A second bus bar is fixed inside the second end face of the second exterior body. The second bus bar contacts the second electrode and its tip extends outside the exterior body.

[0005] Thus, in the capacitor of Patent Document 1, since the entire capacitor element is covered with an exterior body in an airtight state, there is no need to use a filling resin.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the capacitor described in Patent Document 1, the capacitor element is connected only to the first and second busbars and is suspended in mid-air inside the casing. Therefore, when the capacitor is subjected to a vibration load, the capacitor element inside the casing may resonate. This can cause the load to concentrate at the connection point between the capacitor element and the first and second busbars, potentially damaging this connection point.

[0008] The object of this disclosure is to provide a film capacitor that can suppress resonance of the capacitor element. [Means for solving the problem]

[0009] A film capacitor according to one aspect of the present disclosure comprises a capacitor element including a dielectric film and a pair of metal films facing each other across the dielectric film; a busbar connected to the capacitor element; and a sealed case having a housing space larger than the capacitor element, the housing space in which the capacitor element is housed, and the busbar is fixed. The capacitor element is bonded to the inner surface of the sealed case, either directly or indirectly via the busbar.

[0010] A film capacitor according to one aspect of the present disclosure comprises a capacitor element including a dielectric film and a pair of metal films facing each other across the dielectric film; a busbar connected to the capacitor element; and a sealed case having a housing space larger than the capacitor element, the housing space in which the capacitor element is housed and the busbar is fixed. The capacitor element is in contact with the inner surface of the sealed case via a cushioning material or via the cushioning material and the busbar.

[0011] A film capacitor according to one aspect of the present disclosure comprises a capacitor element including a dielectric film and a pair of metal films facing each other across the dielectric film; a busbar connected to the capacitor element; and a sealed case having a housing space larger than the capacitor element, the housing space housing the capacitor element, and the busbar being fixed to the sealed case. The sealed case further has a projection that protrudes into the housing space. The projection is in contact with the capacitor element directly or indirectly via the busbar.

[0012] A film capacitor according to one aspect of the present disclosure comprises a capacitor element including a dielectric film and a pair of metal films facing each other across the dielectric film; a busbar connected to the capacitor element; and a sealed case having a housing space larger than the capacitor element, the housing space in which the capacitor element is housed and the busbar is fixed. The sealed case further has a locking portion that is locked to the capacitor element directly or indirectly via the busbar. [Effects of the Invention]

[0013] According to this disclosure, resonance of the capacitor element can be suppressed. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a perspective view showing a film capacitor according to the first embodiment. [Figure 2] Figure 2 is a front cross-sectional view showing the same film capacitor. [Figure 3] Figure 3 is a side cross-sectional view showing the same film capacitor. [Figure 4] Figure 4 is an exploded perspective view showing the same film capacitor. [Figure 5] Figure 5 is a perspective view showing the manufacturing process of a capacitor element. [Figure 6] Figure 6 is a perspective view showing a film capacitor according to the second embodiment. [Figure 7]FIG. 7 is a front sectional view showing the film capacitor described above. [Figure 8] FIG. 8 is a side sectional view showing the film capacitor described above. [Figure 9] FIG. 9 is an exploded perspective view showing the film capacitor described above. [Figure 10] FIG. 10 is a perspective view showing the film capacitor according to the third embodiment. [Figure 11] FIG. 11 is a front sectional view showing the film capacitor described above. [Figure 12] FIG. 12 is a side sectional view showing the film capacitor described above. [Figure 13] FIG. 13 is an exploded perspective view showing the film capacitor described above. [Figure 14] FIG. 14 is a perspective view showing the film capacitor according to the fourth embodiment. [Figure 15] FIG. 15 is a front sectional view showing the film capacitor described above. [Figure 16] FIG. 16 is a side sectional view showing the film capacitor described above. [Figure 17] FIG. 17 is an exploded perspective view showing the film capacitor described above.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] 1. Overview Although the capacitor of Patent Document 1 has the advantage of not requiring a filling resin, for example, when placed in a use environment that is subjected to vibrations such as in-vehicle applications, there may newly arise a drawback that the capacitor element may resonate.

[0016] Therefore, the present inventor has conducted intensive studies to eliminate the above-mentioned drawbacks while maintaining the above-mentioned advantages, and as a result, has developed the following film capacitor 1 employing a seismic-resistant structure.

[0017] In other words, the film capacitor 1 of this embodiment comprises a capacitor element 2, a busbar 3, and a sealed case 4 (see Figure 1). The capacitor element 2 includes a dielectric film 20 and a pair of metal films 21 facing each other across the dielectric film 20 (see Figure 5). The busbar 3 is connected to the capacitor element 2. The sealed case 4 has a housing space 40 that is larger than the capacitor element 2, and the capacitor element 2 is housed in the housing space 40, with the busbar 3 fixed to it.

[0018] Furthermore, as an earthquake-resistant structure, the capacitor element 2 is bonded directly or indirectly via the busbar 3 to the inner surface 400 of the sealed case 4 (see Figures 2 and 3). This enhances the integration between the capacitor element 2 and the sealed case 4.

[0019] Therefore, even if the film capacitor 1 is subjected to a vibration load, resonance of the capacitor element 2 can be suppressed.

[0020] 2.Details The film capacitor 1 according to the first to fourth embodiments will be described below with reference to Figures 1 to 17. Each figure is a schematic representation, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios.

[0021] The arrows in each diagram indicating the vertical, horizontal, and front-to-back directions are not intended to specify the direction in which film capacitor 1 should be used, but are merely there to make the explanation easier to understand and do not represent any actual physical direction. Viewing along the vertical direction is called a "plan view," viewing along the horizontal direction is called a "side view," and viewing along the front-to-back direction is called a "front view."

[0022] (1) First Embodiment The film capacitor 1 according to the first embodiment will be described below with reference to Figures 1 to 5. The film capacitor 1 according to the first embodiment comprises a capacitor element 2, a busbar 3, and a sealed case 4.

[0023] <Capacitor element> Examples of capacitor element 2 include wound film capacitor elements and multilayer film capacitor elements. In the first embodiment, the case in which capacitor element 2 is a wound film capacitor element will be described, but capacitor element 2 may also be a multilayer film capacitor element.

[0024] The capacitor element 2 comprises an element body 23 and a pair of end face electrodes 22.

[0025] ≪Element Body≫ The shape of the element body 23 is not particularly limited, but in the first embodiment, the element body 23 is rectangular in plan view, flattened circular in side view, and rectangular in front view. The element body 23 includes a dielectric film 20 and a pair of metal films 21 (see Figure 5). The manufacturing process of the capacitor element 2 will be described in the section on <Method of Manufacturing Film Capacitors>.

[0026] [Dielectric film] The material of the dielectric film 20 is not particularly limited, but examples include polypropylene (PP) and polyethylene terephthalate (PET).

[0027] [A pair of metal films] A pair of metal films 21 (a first metal film 211 and a second metal film 212) are provided on a dielectric film 20. The pair of metal films 21 are formed, for example, by vapor deposition. The material of the pair of metal films 21 is not particularly limited, but examples include aluminum (Al), magnesium (Mg), and alloys thereof.

[0028] The pair of metal films 21 face each other within the element body 23 via a dielectric film 20. A portion of the first metal film 211 is exposed on the left side of the element body 23, but the first metal film 211 is not exposed on the right side of the element body 23. On the other hand, a portion of the second metal film 212 is exposed on the right side of the element body 23, but the second metal film 212 is not exposed on the left side of the element body 23.

[0029] ≪A pair of end-face electrodes≫ A pair of end-face electrodes 22 (first end-face electrode 221 and second end-face electrode 222) are provided on both the left and right end faces of the element body 23 (see Figure 2). The pair of end-face electrodes 22 are formed, for example, by metal spraying (metallicon). The metal to be sprayed is not particularly limited, but examples include zinc (Zn), tin (Sn), and alloys thereof.

[0030] The first end electrode 221 is formed on the left side of the element body 23. This electrically connects the first end electrode 221 to the first metal film 211. On the other hand, the second end electrode 222 is formed on the right side of the element body 23. This electrically connects the second end electrode 222 to the second metal film 212. In this way, the pair of end electrodes 22 are electrically connected one-to-one with the pair of metal films 21.

[0031] <Bus bar> The busbar 3 is a conductive member used to electrically connect the capacitor element 2 to external equipment (not shown, the same applies hereinafter). The busbar 3 is formed by cutting a metal plate into a predetermined shape and bending it as appropriate. The metal plate is not particularly limited, but examples include copper plates and aluminum plates. The external equipment is not particularly limited, but examples include components that make up an inverter.

[0032] In the first embodiment, the film capacitor 1 comprises a pair of busbars 3 (a first busbar 31 and a second busbar 32). Each busbar 3 has an element connection portion 33, a terminal portion 34, and a connecting portion 35.

[0033] The element connection portion 33 is connected to the end face electrode 22. This electrically connects the busbar 3 to the metal film 21.

[0034] Specifically, the element connection portion 33a of the first busbar 31 is connected to the first end face electrode 221. This electrically connects the first busbar 31 to the first metal film 211. Meanwhile, the element connection portion 33b of the second busbar 32 is connected to the second end face electrode 222. This electrically connects the second busbar 32 to the second metal film 212. In this way, the pair of busbars 3 are electrically connected one-to-one with the pair of metal films 21.

[0035] Methods for connecting the element connection portion 33 and the end face electrode 22 include, for example, soldering and welding. In the first embodiment, the element connection portion 33 is superimposed on the end face electrode 22 and connected to the end face electrode 22 by a solder portion 29.

[0036] The terminal section 34 is connected to an external device. Specifically, the terminal section 34a of the first busbar 31 and the terminal section 34b of the second busbar 32 are connected to an external device.

[0037] The connecting portion 35 connects the element connection portion 33 and the terminal portion 34. The connecting portion 35 is in the shape of a narrow strip and extends in the front-rear direction along the upper surface of the capacitor element 2. The front end portion of the connecting portion 35 curves downward away from the capacitor element 2 (see Figure 3).

[0038] Specifically, the connecting portion 35a of the first busbar 31 connects the element connection portion 33a and the terminal portion 34a. More specifically, the element connection portion 33a extends downward from the left edge of the connecting portion 35a. The terminal portion 34a extends upward from the rear end of the connecting portion 35a. On the other hand, the connecting portion 35b of the second busbar 32 connects the element connection portion 33b and the terminal portion 34b. More specifically, the element connection portion 33b extends downward from the right edge of the connecting portion 35b. The terminal portion 34b extends upward from the rear end of the connecting portion 35b.

[0039] In this way, busbar 3 is connected to capacitor element 2.

[0040] <Sealed case> The sealed case 4 houses and seals the capacitor element 2. The sealed case 4 also houses and seals a portion of the busbar 3 (a portion of each of the pair of busbars 3). The material of the sealed case 4 is not particularly limited, but examples include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), epoxy resin (EP), etc.

[0041] The sealed case 4 comprises a case body 41 and a lid 42. The sealed case 4 may further have a mounting portion 9.

[0042] ≪Case Body≫ The case body 41 is open at the top (see Figure 4). Specifically, the case body 41 has a bottom plate 43 and a peripheral wall 44. The bottom plate 43 is rectangular in plan view. The peripheral wall 44 rises upward from the outer edge of the bottom plate 43.

[0043] The case body 41 includes a storage space 40 and an opening 410. The storage space 40 is a space enclosed by a bottom plate 43 and a peripheral wall 44. In the first embodiment, the opening 410 is located above the storage space 40. Specifically, the opening 410 is the portion enclosed by the upper end of the peripheral wall 44. Thus, the opening 410 communicates with the storage space 40.

[0044] The housing space 40 is larger than the capacitor element 2. Thus, the sealed case 4 has the housing space 40.

[0045] The surrounding wall 44 includes a left wall 45, a right wall 46, a front wall 47, and a rear wall 48. The left wall 45 and the right wall 46 are opposite each other in the left-right direction. The front wall 47 and the rear wall 48 are opposite each other in the front-back direction.

[0046] At least one positioning piece 471 is provided on the rear surface of the front wall 47 (see Figure 3). The positioning piece 471 protrudes rearward and extends upward from the upper surface of the bottom plate 43. In the first embodiment, the bus bar 3 (particularly the front end portion of the connecting portion 35) strikes the positioning piece 471, restricting the forward movement of the capacitor element 2.

[0047] On the other hand, at least one positioning piece 481 is provided on the front surface of the rear wall 48 (see Figure 3). The positioning piece 481 protrudes forward and extends upward from the upper surface of the bottom plate 43. In the first embodiment, the rear end of the capacitor element 2 contacts the positioning piece 481, restricting the rearward movement of the capacitor element 2.

[0048] In this manner, the positioning pieces 471 and 481 position the capacitor element 2 in the front-to-back direction.

[0049] ≪Lid part≫ The lid 42 closes the opening 410 of the case body 41. As a result, the storage space 40 becomes a closed system, and airtightness is maintained within the storage space 40.

[0050] The housing space 40 houses the capacitor element 2. Furthermore, the housing space 40 also houses a portion of the bus bar 3 (each of the pair of bus bars 3).

[0051] Of the housing space 40, the remaining space, excluding the space occupied by the capacitor element 2 and part of the busbar 3, is usually filled with air, but preferably with a gas with a lower oxygen concentration than air, more preferably with an inert gas such as nitrogen. This makes it difficult for oxygen to enter the capacitor element 2, thereby suppressing oxidation of the metal film 21.

[0052] The element connection portion 33 and the connecting portion 35 of the busbar 3 are housed in the housing space 40. At least a portion of the terminal portion 34 is not housed in the housing space 40. That is, while maintaining airtightness within the housing space 40, the busbar 3 extends outside the sealed case 4 through the lid portion 42. Thus, at least a portion of the terminal portion 34 is located outside the sealed case 4. The busbar 3 is fixed to the sealed case 4 (the lid portion 42 in the first embodiment).

[0053] ≪Mounting part≫ The mounting portion 9 is used to attach the film capacitor 1 to an external device. In the first embodiment, two mounting portions 9 protrude laterally from the peripheral wall 44 of the case body 41. Specifically, one mounting portion 9 protrudes to the left from the left wall 45. The other mounting portion 9 protrudes to the right from the right wall 46.

[0054] In the first embodiment, a collar 91 is embedded in the mounting portion 9. The collar 91 is a cylindrical metal ring. The collar 91 of the mounting portion 9 penetrates in the vertical direction.

[0055] <Earthquake-resistant structure> In the first embodiment, the capacitor element 2 is bonded to the inner surface 400 of the sealed case 4. The inner surface 400 includes the upper surface of the bottom plate 43, the right surface of the left wall 45, the left surface of the right wall 46, the rear surface of the front wall 47, the front surface of the rear wall 48, and the lower surface of the lid 42.

[0056] Specifically, the capacitor element 2 is bonded to the upper surface of the base plate 43 by the adhesive portion 5. Any known adhesive can be used as the adhesive.

[0057] In the first embodiment, the capacitor element 2 is directly bonded to the inner surface 400 of the sealed case 4 (see Figures 1 to 3). Although not shown, the capacitor element 2 may also be indirectly bonded to the inner surface 400 of the sealed case 4 via a busbar 3.

[0058] <Manufacturing method for film capacitors> Next, we will explain the manufacturing method of the film capacitor 1.

[0059] First, as shown in Figure 5, the long first metallized film 241 and the second metallized film 242 are overlapped and wound around the axis C to form a cylindrical wound body 25.

[0060] Here, the first metallized film 241 is provided with a first metal film 211 (shown as a dot pattern in Figure 5) on the first dielectric film 201. However, the first metal film 211 is not provided on the first margin portion 261 of the first dielectric film 201. On the other hand, the second metallized film 242 is provided with a second metal film 212 (shown as a dot pattern in Figure 5) on the second dielectric film 202. However, the second metal film 212 is not provided on the second margin portion 262 of the second dielectric film 202.

[0061] Next, the wound body 25 is flattened by applying pressure in a direction perpendicular to the axis C, resulting in an element body 23 that has a flattened circular shape when viewed from the side. Then, a pair of end face electrodes 22 are formed by thermal spraying metal onto both end faces of the element body 23. This gives rise to the capacitor element 2.

[0062] Next, as shown in Figure 4, the busbar 3 is connected to the capacitor element 2 by soldering or the like. Then, the capacitor element 2 with the busbar 3 connected is bonded to the inner surface 400 of the case body 41 with adhesive, and the opening 410 of the case body 41 is closed with the lid 42 to obtain a film capacitor 1 as shown in Figure 1. If there is a gap in the lid 42 where the busbar 3 passes through, that gap may be filled with a sealant or the like.

[0063] In Figure 4, when the lid 42 closes the opening 410 of the case body 41, the terminal portion 34 of the busbar 3 is shown to pass through the lid 42. However, the busbar 3 may also be insert-molded into the lid 42. In this case, a gap is less likely to occur in the portion of the lid 42 through which the busbar 3 passes.

[0064] <Effects and Effects> The film capacitor 1 according to the first embodiment is not a so-called case-molded capacitor. That is, in the film capacitor 1 according to the first embodiment, the remaining space of the housing space 40, excluding the space occupied by the capacitor element 2 and part of the busbar 3, is usually filled with air and is not filled with resin. Therefore, the film capacitor 1 according to the first embodiment can be made lighter.

[0065] In the first embodiment, the capacitor element 2 is connected to the busbar 3, and the busbar 3 is fixed to the sealed case 4, but the capacitor element 2 is not suspended in mid-air within the housing space 40.

[0066] In other words, in the first embodiment, a structure is adopted in which the capacitor element 2 is bonded to the sealed case 4 as an earthquake-resistant structure. In this way, the integration between the capacitor element 2 and the sealed case 4 is enhanced.

[0067] Therefore, even if the film capacitor 1 is subjected to a vibration load, resonance of the capacitor element 2 can be suppressed.

[0068] Furthermore, if the capacitor element 2 is suspended in mid-air within the housing space 40, when the capacitor element 2 generates heat, the surrounding air does not conduct heat well, so the only heat dissipation path is the busbar 3. However, in the first embodiment, a structure is adopted in which the capacitor element 2 is bonded to the sealed case 4, so this structure can serve as another heat dissipation path.

[0069] Therefore, it is also possible to improve the heat dissipation of the film capacitor 1.

[0070] (2) Second Embodiment Next, the film capacitor 1 according to the second embodiment will be described with reference to Figures 6 to 9. In the second embodiment, components similar to those in the first embodiment are given the same reference numerals as in the first embodiment, and detailed descriptions may be omitted. The following description will focus on the differences from the first embodiment.

[0071] <Earthquake-resistant structure> The film capacitor 1 according to the second embodiment further comprises at least one cushioning material 6. Specifically, in the second embodiment, the film capacitor 1 further comprises two cushioning materials 6. The two cushioning materials 6 are a first cushioning material 61 and a second cushioning material 62.

[0072] The cushioning material 6 is not particularly limited, but examples include foam. The material of the cushioning material 6 is not particularly limited, but examples include urethane, polyethylene, etc.

[0073] In the second embodiment, the cushioning material 6 is plate-shaped, but the shape of the cushioning material 6 in plan view is not particularly limited. For example, the cushioning material 6 may be rectangular or frame-shaped in plan view.

[0074] As shown in Figures 7 and 8, the capacitor element 2 is in contact with the lower surface of the lid 42 via the first buffer material 61 and the bus bar 3. On the other hand, the capacitor element 2 is in contact with the upper surface of the bottom plate 43 via the second buffer material 62.

[0075] Thus, in the second embodiment, the capacitor element 2 is in contact with the inner surface 400 of the sealed case 4 via the buffer material 6 or via the buffer material 6 and the bus bar 3.

[0076] <Effects and Effects> The second embodiment also produces the same effects and advantages as the first embodiment.

[0077] In particular, the second embodiment employs a structure in which the capacitor element 2 is in contact with the sealed case 4 via a cushioning material 6 as a vibration-resistant structure. Moreover, since the capacitor element 2 is held in place by two cushioning materials 6 in the vertical direction, it is especially effective when the vibration direction of the film capacitor 1 is vertical. If the vibration direction of the film capacitor 1 is known in advance, the capacitor element 2 can be held in place by two cushioning materials 6 along that direction. Furthermore, the cushioning material 6 has the advantage of being able to absorb dimensional variations of the capacitor element 2.

[0078] (3) Third Embodiment Next, the film capacitor 1 according to the third embodiment will be described with reference to Figures 10 to 13. In the third embodiment, components similar to those in the first and second embodiments are denoted by the same reference numerals as in the first and second embodiments, and detailed descriptions may be omitted. The following description will focus on the differences from the first and second embodiments.

[0079] <Earthquake-resistant structure> In the third embodiment, the sealed case 4 further has at least one projection 7. The projection 7 protrudes into the storage space 40. Specifically, in the third embodiment, the lid 42 has two projections 7. The two projections 7 protrude downward from the lower surface of the lid 42. The projections 7 are, for example, bosses (cylindrical projections).

[0080] In the third embodiment, the projection 7 indirectly contacts the capacitor element 2 via the busbar 3 (see Figure 11). Although not shown, the projection 7 may also directly contact the capacitor element 2.

[0081] Furthermore, in the third embodiment, the sealed case 4 further has at least one rib-like projection 431. The rib-like projection 431 protrudes into the housing space 40. Specifically, in the third embodiment, the case body 41 has three rib-like projections 431. The three rib-like projections 431 protrude upward from the upper surface of the bottom plate 43 and extend in the front-rear direction. The three rib-like projections 431 are arranged in the left-right direction on the upper surface of the bottom plate 43. The capacitor element 2 is positioned on the upper surface of the bottom plate 43 via the three rib-like projections 431.

[0082] Although not shown in the illustration, a cushioning material 6 may be placed in the housing space 40 at a position opposite to the projection 7. That is, instead of the rib-like projection 431, the cushioning material 6 of the second embodiment (for example, the second cushioning material 62) may be placed. In that case, the capacitor element 2 and the inner surface 400 of the sealed case 4 will be in contact via the cushioning material 6, but the capacitor element 2 and the inner surface 400 of the sealed case 4 may be in contact via the cushioning material 6 and the busbar 3.

[0083] <Effects and Effects> The third embodiment employs a structure in which the projection 7 of the sealed case 4 is in contact with the capacitor element 2 as an earthquake-resistant structure, and thus achieves the same effects as the first embodiment.

[0084] Although not shown in the diagram, the capacitor element 2 may be held between the projection 7 and the cushioning material 6 in the vertical direction. This is particularly effective when the vibration direction of the film capacitor 1 is vertical. In this case, as with the second embodiment, there is also the advantage that the cushioning material 6 can absorb dimensional variations in the capacitor element 2.

[0085] (4) Fourth Embodiment Next, the film capacitor 1 according to the fourth embodiment will be described with reference to Figures 14 to 17. In the fourth embodiment, components similar to those in the first to third embodiments are denoted by the same reference numerals as in the first to third embodiments, and detailed descriptions may be omitted. The following description will focus on the differences from the first to third embodiments.

[0086] <Earthquake-resistant structure> In the fourth embodiment, the sealed case 4 further has at least one locking portion 8. Specifically, the case body 41 further has four locking portions 8.

[0087] Of the four locking parts 8, two are located on the right side of the left wall 45, protruding to the right and extending upward from the upper surface of the bottom plate 43. The remaining two locking parts 8 are located on the left side of the right wall 46, protruding to the left and extending upward from the upper surface of the bottom plate 43.

[0088] A claw portion 81 is provided at the upper end of the locking portion 8. On the other hand, a claw hole 36 into which the claw portion 81 is fitted is provided in the element connection portion 33 of the busbar 3.

[0089] In this way, by fitting the claw portion 81 into the claw hole 36, the locking portion 8 is indirectly locked to the capacitor element 2 via the busbar 3. Although not shown in the figure, the locking portion 8 may also be directly locked to the capacitor element 2.

[0090] Furthermore, in the fourth embodiment, at least one positioning piece 451 is provided on the right surface of the left wall 45 (see Figures 15 and 17). The positioning piece 451 protrudes to the right and extends upward from the upper surface of the bottom plate 43. In the fourth embodiment, the left portion of the capacitor element 2 contacts the positioning piece 451, restricting the leftward movement of the capacitor element 2.

[0091] On the other hand, at least one positioning piece 461 is provided on the left side of the right wall 46 (see Figures 15 and 16). The positioning piece 461 protrudes to the left and extends upward from the upper surface of the bottom plate 43. In the fourth embodiment, the right side portion of the capacitor element 2 contacts the positioning piece 461, restricting the movement of the capacitor element 2 to the right.

[0092] In this manner, the positioning pieces 451 and 461 position the capacitor element 2 in the left-right direction.

[0093] <Effects and Effects> The fourth embodiment employs a structure in which the locking portion 8 of the sealed case 4 is locked to the busbar 3 of the capacitor element 2 as an earthquake-resistant structure, thus achieving the same effects as the first embodiment. In this case, there is the advantage that the capacitor element 2 can be housed in the case body 41 and locked to the locking portion 8 with a single touch.

[0094] 3. Variant At least two of the first to fourth embodiments may be combined. Parts of other embodiments may be combined with one embodiment.

[0095] The adhesive portion 5 of the first embodiment, the cushioning material 6 of the second embodiment, the projection 7 of the third embodiment, and the locking portion 8 of the fourth embodiment may be located anywhere within the housing space 40, as long as they are in direct or indirect contact with the capacitor element 2.

[0096] 4. Appearance As will be apparent from the above embodiments and modifications, this disclosure includes the following aspects. In the following, reference numerals are enclosed in parentheses solely to indicate their correspondence with the embodiments.

[0097] The first embodiment is a film capacitor (1) comprising a capacitor element (2) including a dielectric film (20) and a pair of metal films (21) facing each other across the dielectric film (20); a busbar (3) connected to the capacitor element (2); and a sealed case (4) having a housing space (40) larger than the capacitor element (2), in which the capacitor element (2) is housed and the busbar (3) is fixed. The capacitor element (2) is bonded to the inner surface (400) of the sealed case (4) either directly or indirectly via the busbar (3).

[0098] According to this embodiment, resonance of the capacitor element (2) can be suppressed.

[0099] A second embodiment is a film capacitor (1) comprising a capacitor element (2) including a dielectric film (20) and a pair of metal films (21) facing each other across the dielectric film (20); a busbar (3) connected to the capacitor element (2); and a sealed case (4) having a housing space (40) larger than the capacitor element (2), in which the capacitor element (2) is housed and the busbar (3) is fixed. The capacitor element (2) is in contact with the inner surface (400) of the sealed case (4) via a buffer material (6) or via the buffer material (6) and the busbar (3).

[0100] According to this embodiment, resonance of the capacitor element (2) can be suppressed.

[0101] A third embodiment is a film capacitor (1) comprising a capacitor element (2) including a dielectric film (20) and a pair of metal films (21) facing each other across the dielectric film (20); a busbar (3) connected to the capacitor element (2); and a sealed case (4) having a housing space (40) larger than the capacitor element (2), the capacitor element (2) being housed in the housing space (40), and the busbar (3) being fixed to it. The sealed case (4) further has a projection (7) protruding into the housing space (40). The projection (7) is in contact with the capacitor element (2) directly or indirectly via the busbar (3).

[0102] According to this embodiment, resonance of the capacitor element (2) can be suppressed.

[0103] The fourth embodiment is a film capacitor (1) based on the third embodiment. In the fourth embodiment, a buffer material (6) is placed in the housing space (40) at a position opposite to the projection (7). The capacitor element (2) and the inner surface (400) of the sealed case (4) are in contact via the buffer material (6) or via the buffer material (6) and the busbar (3).

[0104] According to this embodiment, the resonance of the capacitor element (2) can be further suppressed.

[0105] A fifth aspect of the film capacitor (1) comprises a capacitor element (2) including a dielectric film (20) and a pair of metal films (21) facing each other across the dielectric film (20); a busbar (3) connected to the capacitor element (2); and a sealed case (4) having a housing space (40) larger than the capacitor element (2), the capacitor element (2) being housed in the housing space (40), and the busbar (3) being fixed to it. The sealed case (4) further has a locking portion (8) that is locked to the capacitor element (2) directly or indirectly via the busbar (3).

[0106] According to this embodiment, resonance of the capacitor element (2) can be suppressed.

[0107] The sixth embodiment is a film capacitor (1) based on any one of the first to fifth embodiments. In the sixth embodiment, the sealed case (4) has a case body (41) including a housing space (40) and an opening (410) communicating with the housing space (40), and a lid (42) that closes the opening (410). The busbar (3) extends to the outside of the sealed case (4) through the lid (42) while maintaining airtightness within the housing space (40).

[0108] According to this embodiment, the capacitor element (2) is easy to seal. [Explanation of Symbols]

[0109] 1 Film Capacitor 2 Capacitor elements 20 Dielectric film 21 Metal film 3 bus bars 4. Airtight case 40 Containment space 400 Inner self 41 Case body 410 Opening 42 Lid 6 Cushioning material 7 Protrusion 8 Locking part

Claims

1. A capacitor element comprising a dielectric film and a pair of metal films facing each other across the dielectric film, A busbar connected to the aforementioned capacitor element, A sealed case having a housing space larger than the capacitor element, the capacitor element being housed in the housing space, and the busbar being fixed thereto, The capacitor element is bonded to the inner surface of the sealed case, either directly or indirectly via the busbar. Film capacitor.

2. A capacitor element comprising a dielectric film and a pair of metal films facing each other across the dielectric film, A busbar connected to the aforementioned capacitor element, A sealed case having a housing space larger than the capacitor element, the capacitor element being housed in the housing space, and the busbar being fixed thereto, The capacitor element is in contact with the inner surface of the sealed case via a buffer material or via the buffer material and the busbar. Film capacitor.

3. A capacitor element comprising a dielectric film and a pair of metal films facing each other across the dielectric film, A busbar connected to the aforementioned capacitor element, A sealed case having a housing space larger than the capacitor element, the capacitor element being housed in the housing space, and the busbar being fixed thereto, The sealed case further has a projection that protrudes into the storage space, The projection is in contact with the capacitor element directly or indirectly via the busbar. Film capacitor.

4. Within the aforementioned containment space, a cushioning material is placed at a position opposite to the protrusion. The capacitor element and the inner surface of the sealed case are in contact via the cushioning material or via the cushioning material and the busbar. The film capacitor according to claim 3.

5. A capacitor element comprising a dielectric film and a pair of metal films facing each other across the dielectric film, A busbar connected to the aforementioned capacitor element, A sealed case having a housing space larger than the capacitor element, the capacitor element being housed in the housing space, and the busbar being fixed thereto, The sealed case further has a locking portion that is locked directly or indirectly via the busbar to the capacitor element. Film capacitor.

6. The sealed case comprises a case body including the storage space and an opening communicating with the storage space, and a lid that closes the opening. While maintaining airtightness within the containment space, the busbar extends through the lid to the outside of the sealed case. A film capacitor according to any one of claims 1 to 5.

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