Film capacitor

Abstract

To position an insulating member by an engagement structure using either a first insulating member or a second insulating member.SOLUTION: A rib 56 as an engaged part is formed on each of opposed surfaces of a peripheral wall part 54 of a first insulating member 5, and an end edge part as an engaging part of a peripheral wall part 63 of a second insulating member 6 is abutted on and engaged with the rib 56 to position the second insulating member 6 to the first insulating member 5. Further, the first bent portion of the second insulating member 6 comes into contact with the step portion of the ridge upper surface of the case, so that the second insulating member 6 is positioned with respect to the case when a part of the capacitor unit is housed in the housing portion of the case.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Conventionally, there is a film capacitor that includes a capacitor element having a pair of end surface electrodes, a first terminal having a first polarity connected to one end surface electrode of the capacitor element, a terminal having a second polarity connected to the other end surface electrode of the capacitor element, and an insulating member that insulates between the first terminal and the second terminal (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-086839 [Patent Document 2] Patent No. 6811378 Summary of the Invention [Problem to be solved by the invention]

[0004] The film capacitor described in Patent Document 1 uses a resin insulating member to insulate between the first terminal (first bus bar) and the second terminal (second bus bar), and between the first and second terminals and electronic components other than the capacitor element. Because the insulating member is used to insulate between electronic components, between electronic components and terminals, and between terminals, the insulating member needs to be processed into a complex three-dimensional shape, which creates a problem of a complex structure for a mold for processing the insulating member.

[0005] On the other hand, in the film capacitor described in the above-mentioned Patent Document 2, a convex fixing portion is provided on the resin insulating member that insulates between the first terminal (first bus bar) and the second terminal (second bus bar) to position the insulating member, while a concave support portion formed by a notch is provided on the upper end of the wall of the case that houses the capacitor element and part of the first and second terminals, and the fixing portion is fitted into the support portion to position the insulating member on the case. However, forming the notch on the upper end of the wall of the case creates a joint on the case wall, which may cause cracks in the joint due to vibration, heat shock, etc.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to position an insulating member using a highly reliable and simple structure. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the film capacitor of the present invention comprises a capacitor element having a pair of end surface electrodes, a first terminal having a first polarity connected to one of the end surface electrodes of the capacitor element, and a second terminal having a second polarity connected to the other of the end surface electrodes of the capacitor element, characterized in that the film capacitor comprises a first insulating member that insulates the first terminal from the second terminal, a second insulating member that insulates the first terminal or the second terminal from a third terminal having a third polarity different from the first and second polarities, and an engaging portion is provided on one of the first insulating member and the second insulating member, and an engaged portion that can engage with the engaging portion is provided on the other, and the two insulating members are positioned by engaging with each other.

[0008] With this configuration, an engaging portion is provided on one of the first insulating member and the second insulating member, and an engaged portion that can engage with the engaging portion is provided on the other, and positioning is achieved by these engaging portion and engaged portion with each other, so there is no need to give the insulating member a complex three-dimensional shape, and the structure of the mold for processing the insulating member does not become complicated as in the past.In addition, no joints are created on the case for positioning the insulating member, and the insulating member can be positioned with a highly reliable and simple structure.

[0009] Here, the capacitor device may further include a case that houses the capacitor element, and the case may be provided with an abutment portion that abuts against either the first insulating member or the second insulating member.

[0010] According to this configuration, either the first insulating member or the second insulating member abuts against the abutting portion of the case, so that the insulating member can be positioned relative to the case without providing a support portion in the form of a notch in the case.

[0011] Furthermore, it is preferable that the case be made of a bottomed housing with one side open, and that a stepped surface be formed on the side wall opening side of the bottomed housing, and that the stepped surface abut against either the first insulating member or the second insulating member as the abutment portion.

[0012] According to this configuration, it is possible to position the insulating member relative to the case without generating joints that would otherwise be generated by forming support portions in the case using notches, as in the prior art.

[0013] In addition, an outwardly protruding rib may be formed on either the first insulating member or the second insulating member, and the rib may abut against the edge portion of the other insulating member, thereby restricting movement of the other insulating member.

[0014] According to this configuration, one insulating member can be reliably positioned relative to the other insulating member. [Effects of the Invention]

[0015] According to the present invention, the insulating member can be positioned with a highly reliable and simple structure. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a plan view of a film capacitor according to an embodiment of the present invention; [Figure 2] FIG. 2 is a side view of a portion of the film capacitor of FIG. [Figure 3] 2 is a perspective view of the film capacitor of FIG. 1 without a third bus bar (third terminal), sealing resin, or case. [Figure 4] 4 is a perspective view of the film capacitor of FIG. 3 in a state where the first bus bar is further removed. [Figure 5] FIG. 2 is a perspective view of a first bus bar of the film capacitor of FIG. [Figure 6] FIG. 2 is a perspective view of a second bus bar of the film capacitor of FIG. [Figure 7] 2 is an enlarged perspective view of a first insulating member and a second insulating member of the film capacitor of FIG. 1. FIG. [Figure 8] FIG. 2 is a perspective view of a first insulating member of the film capacitor of FIG. [Figure 9] 9 is an enlarged perspective view of the area enclosed by the dashed-dotted rectangle in FIG. 8. FIG. [Figure 10] FIG. 2 is a perspective view of a second insulating member of the film capacitor of FIG. 1; [Figure 11] 11 is an enlarged perspective view of the area enclosed by the dashed-dotted rectangle in FIG. 10. FIG. [Figure 12] 2 is a cross-sectional view of a case and a second insulating member of the film capacitor of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of a film capacitor according to the present invention will be described in detail with reference to FIGS. 1 to 12. In FIGS. 1 to 12, the x-axis, y-axis, and z-axis are illustrated so that they are aligned in the same direction. Hereinafter, the positive and negative x-axis sides will be referred to as the right and left, the positive and negative y-axis sides as the rear and front, and the positive and negative z-axis sides as the top and bottom. Hereinafter, a planar view of the film capacitor 1 viewed from the positive (top) or negative (bottom) side of the z-axis to the negative (bottom) or positive (top) side of the z-axis will be referred to as an "xy planar view." A planar view of the film capacitor 1 viewed from the positive (top) or negative (bottom) side of the y-axis to the negative (front) or positive (rear) side of the y-axis will be referred to as an "xz planar view." A planar view of the film capacitor 1 viewed from the positive (back) or negative (front) side of the y-axis to the negative (left) or positive (right) side of the x-axis will be referred to as a "yz planar view."

[0018] 1 to 4, the film capacitor 1 includes a capacitor element 10 having end surface electrodes arranged parallel to the xy plane, a first bus bar 2, a second bus bar 3, a third bus bar 4, a first insulating member 5, a second insulating member 6, a case 7, and a sealing resin 8. The first bus bar 2 corresponds to the "first terminal" in the present invention, the second bus bar 3 corresponds to the "second terminal" in the present invention, and the third bus bar 4 corresponds to the "third terminal" in the present invention.

[0019] 3 and 4, particularly FIG. 4, five capacitor elements 10 are arranged side by side in the x-axis direction, and each capacitor element 10 includes an element body 11, a first end electrode 12 formed by spraying a metal such as zinc on the upper surface of the element body 11 on the positive side of the z-axis, and a second end electrode 13 formed by spraying a metal such as zinc on the lower surface of the element body 11 on the negative side of the z-axis. The first end electrode 12 and the second end electrode 13 of each capacitor element 10 are arranged parallel to the xy plane. The first end electrode 12 and the second end electrode 13 of each capacitor element 10 correspond to the "pair of end electrodes" of the capacitor element in this invention.

[0020] The element body 11 is formed by overlapping two metallized films, each of which has aluminum vapor-deposited on a dielectric film, and rolling or laminating them, and then pressing them into a flat shape. Note that the metallized film is not limited to the configuration described above. For example, it may be a metallized film vapor-deposited with another metal such as zinc or magnesium, a metallized film vapor-deposited with multiple of these metals, or a metallized film vapor-deposited with an alloy of these metals.

[0021] The first end surface electrode 12 is used as the P pole side, and the second end surface electrode 13 is used as the N pole side. Alternatively, the first end surface electrode 12 may be used as the N pole side, and the second end surface electrode 13 may be used as the P pole side. Here, the P pole and the N pole correspond to the "first polarity" and the "second polarity" in the present invention, respectively, and the polarity of the third bus bar 4, which will be described in detail later, corresponds to the "third polarity" in the present invention.

[0022] The first bus bar 2 and the second bus bar 3 are each formed by stamping a conductive material such as copper. As shown in FIGS. 3 and 5 , the first bus bar 2 is disposed opposite the first end surface electrodes 12 of the five capacitor elements 10 and includes a main body 20, a bent portion 21, and an external connection terminal portion 22. The main body 20 has a substantially rectangular plate shape in the xy plane. The bent portion 21 is formed by bending upward (in the positive z-axis direction) from the front end portion on the negative y-axis side of the main body 20 by approximately 90 degrees, and has a thin, elongated, substantially rectangular plate shape in the xy plane. The external connection terminal portion 22 is formed by bending forward (in the negative y-axis direction) substantially horizontally from the upper end portion on the positive z-axis side of the bent portion 21, and has three extending portions 22a that are rectangular in the xy plane and extend further forward (in the negative y-axis direction). Furthermore, four through holes 23 are formed from the front end portion on the y-axis negative side of main body portion 20 to the lower end portion on the z-axis negative side of bent portion 21. The formation of these through holes 23 makes it easier for the liquid resin for sealing resin 8, which is filled from the opening of case 7, to flow.

[0023] Here, the length of the main body 20 in the x-axis direction is approximately the same as the sum of the lengths of the five capacitor elements 10 in the x-axis direction, and the length of the main body 20 in the y-axis direction is approximately the same as the length of one capacitor element 10 in the y-axis direction, and almost the entire surfaces of the first end surface electrodes 12 of the five capacitor elements 10 are covered by the main body 20.

[0024] Two U-shaped notches 24 are formed in each of the main body 20 near the bent portion 21 and at positions facing the first end surface electrodes 12 of the five capacitor elements 10, for a total of ten notches 24 aligned in the x-axis direction. A pin-shaped electrode connection portion 25 is formed in each notch 24 in the y-axis direction by the notch, and the two electrode connection portions 25 are electrically connected to the first end surface electrode 12 of one capacitor element 10 by soldering.

[0025] By punching and pressing, the main body 20, bent portion 21, external connection terminal portion 22 (including extension portion 22a), through hole 23, notch portion 24 and electrode connection portion 25 of the first bus bar 2 are simultaneously formed.

[0026] As shown in FIGS. 3 , 4 , and 6 , the second busbar 3 is disposed opposite the second end surface electrodes 13 of the five capacitor elements 10 and includes a main body 30, a bent portion 31, and an external connection terminal portion 32. The main body 30 has a generally rectangular plate shape in the xy plane. The bent portion 31 is formed by bending upward (in the positive z-axis direction) from the front end of the main body 30 on the negative y-axis side at approximately 90°, and has a generally elongated rectangular plate shape in the xy plane. The external connection terminal portion 32 is formed by bending forward (in the negative y-axis direction) approximately horizontally from the upper end of the bent portion 31 on the positive z-axis side, and has three extending portions 32a that are rectangular in the xy plane and further extend forward (in the negative y-axis direction). Similar to the first busbar 2, four through holes 33 are formed from the front end of the main body 30 on the negative y-axis side to the lower end of the bent portion 31 on the negative z-axis side. The formation of these through holes 33 allows the liquid resin for sealing resin 8 to be filled from the opening of case 7 to flow easily.

[0027] Here, the length of the main body portion 30 in the x-axis direction is approximately the same as the sum of the lengths of the five capacitor elements 10 in the x-axis direction, and the length of the main body portion 30 in the y-axis direction is approximately the same as the length of one capacitor element 10 in the y-axis direction, and approximately the entire surfaces of the second end surface electrodes 13 of the five capacitor elements 10 are covered by the main body portion 30.

[0028] Similarly to the main body 20 of the first busbar 2, two U-shaped notches 34 are formed in each of the main body 30 near the bent portion 31 and at positions facing the second end surface electrodes 13 of the five capacitor elements 10, for a total of ten notches 34 aligned in the x-axis direction. Each notch 34 has a pin-shaped electrode connection portion 35 formed by the notch in the y-axis direction, and the two electrode connection portions 35 are electrically connected to the second end surface electrode 13 of one capacitor element 10 by soldering.

[0029] As with the first busbar 2, the main body 30, bent portion 31, external connection terminal portion 32 (including extension portion 32a), through hole 33, notch portion 34 and electrode connection portion 35 of the second busbar 3 are simultaneously formed by punching and pressing.

[0030] As shown in Figures 1 and 2, the third bus bar 4 has a rectangular shape parallel to the xy plane and elongated in the x-axis direction, and is used for ground connection that also serves as a heat dissipation device for an inverter, which is an external electronic circuit not shown, and has a third polarity different from the polarities (P pole, N pole) of the first bus bar 2 and the second bus bar 3.

[0031] 2 and 7 to 9, particularly FIG. 2, the first insulating member 5 provides insulation between the first bus bar 2 and the second bus bar 3, and is formed by molding an insulating resin. The first insulating member 5 has a base portion 50, a bent portion 51, an extending portion 52, a recessed space 53, a peripheral wall portion 54, and an end wall portion 55.

[0032] The base 50 has a narrow rectangular shape parallel to the x-z plane. The bent portion 51 is integrally formed by bending forward (in the negative y-axis direction) from the upper end of the base 50 on the positive side of the z-axis. The extending portions 52 are integrally formed at three locations on the front end of the bent portion 51 on the negative side of the y-axis, extending substantially horizontally forward (in the negative y-axis direction), and have a rectangular shape in the x-y plane view. The recessed spaces 53 are formed at two locations between adjacent extending portions 52, and have a rectangular shape in the x-y plane view. The peripheral wall portions 54 are integrally formed along the peripheral side surfaces of the two recessed spaces 53 so as to form wall surfaces in the up-down direction (in the positive and negative z-axis directions), and have a U-shape in the x-y plane view. End wall portion 55 is integrally formed to form a wall surface in the up-down direction (the positive and negative z-axis directions) along the right end faces on the x-axis positive side of base portion 50 and bent portion 51 and the right end face on the x-axis positive side of right extension portion 52 that is continuous with this right end face, and along the left end faces on the x-axis negative side of base 50 and bent portion 51 and the left end face on the x-axis negative side of left extension portion 52 that is continuous with this left end face. Furthermore, ribs 56 that extend in the z-axis direction are formed in the two peripheral wall portions 54 at approximately the center of each of the opposing surfaces of peripheral wall portion 54, protruding outward (into recessed space 53).

[0033] As shown in FIGS. 2, 7, 10, and 11, particularly FIG. 2, the second insulating member 6 provides insulation between the second bus bar 3 and the third bus bar 4 and is formed by molding an insulating resin. As shown in FIG. 10, the second insulating member 6 has a base 60, a first bent portion 61, a second bent portion 62, a peripheral wall portion 63, and an end wall portion 64. The base 60 has a narrow rectangular shape parallel to the xz plane. The first bent portion 61 is integrally formed by bending forward (in the negative y-axis direction) from the lower end of the base 60 on the negative z-axis side. The first bent portion 61 (lower surface) abuts against a stepped surface 74 of a protrusion 73 (described later), thereby restricting downward movement (in the negative z-axis direction) of the second insulating plate 6 due to its own weight. The second bent portion 62 is integrally formed by bending forward (in the negative y-axis direction) from the upper end of the base 60 on the positive z-axis side. The formation of the second bent portion 62 ensures a creepage distance between the second insulating member 6 and the third bus bar 4. The peripheral wall portion 63 is integrally formed at two locations on the upper surface of the second bent portion 62 on the positive side of the z-axis to form vertical wall surfaces, and has a U-shape in the xy plane viewed from the positive side of the z-axis to the negative side, and has a stepped shape with a raised front end side (negative side of the y-axis) in the yz plane viewed from the positive side of the x-axis to the negative side. The end wall portion 64 is integrally formed along the right end faces of the base 60 and the second bent portion 62 on the positive side of the x-axis and along the left end faces of the base 60 and the second bent portion 62 on the negative side of the x-axis to form vertical wall surfaces.

[0034] 7 , the two peripheral wall portions 63 of the second insulating member 6 are formed in a shape that allows them to engage with the insides of the peripheral wall portions 54 of the two recessed spaces 53 of the first insulating member 5, and an edge portion 65 on the y-axis negative side of the peripheral wall portion 63 of the second insulating member 6 abuts against each rib 56 of the peripheral wall portion 54 of the first insulating member 5. Such abutment of the edge portions 65 of the peripheral wall portion 63 of the second insulating member 6 with the ribs 56 restricts rotation of the second insulating member 6 in a direction parallel to the y-z plane, thereby positioning the second insulating member 6 with respect to the first insulating member 5. The edge portions 65 of the peripheral wall portion 63 of the second insulating member 6 correspond to the "engaging portion" in this invention, and the ribs 56 of the first insulating member 5 correspond to the "engaged portion" in this invention.

[0035] 1, the case 7 is a rectangular parallelepiped housing with a bottom, and can be made of various materials, for example, organic materials such as resins and plastics, such as polyphenylene sulfide (PPS) and polybutylene terephthalate (PBT), and inorganic materials such as ceramic. Here, the case 7 corresponds to the "case" in the present invention. The case 7 is not limited to being made of resin, and may also be made of metal.

[0036] The case 7 has an opening 70 on the upper surface on the positive side of the z-axis, and a storage section 71 formed inside stores part of a capacitor unit having a capacitor element 10, first and second bus bars 2, 3, and first and second insulating members 5, 6 (five capacitor elements 10, part of the first bus bar 2, part of the second bus bar 3, part of the first insulating member 5, and part of the second insulating member 6).

[0037] Furthermore, with a portion of the capacitor unit housed in the housing portion 71 of the case 7, a liquid sealing resin 8 made of, for example, epoxy resin is filled into the housing portion 71 of the case 7 to seal a portion of the capacitor unit. This sealing resin 8 is not limited to epoxy resin, and various insulating materials used as sealing resins for electronic components can be used. The sealing resin 8 is injected into the case 7 in a liquid state through the opening 70 of the case 7 and then hardens. The sealing resin 8 corresponds to the "sealing resin" in this invention.

[0038] 12, which shows a cross section of the case 7 and the second insulating member 6 parallel to the yz plane, a plurality of (two in this embodiment) vertical (z-axis positive and negative) protrusions 73 are formed at approximately the center of the inner surface of a front wall 72 on the y-axis negative side of the case 7, and the vertical length of these protrusions 73 is shorter than the vertical dimension of the front wall of the case 7. Therefore, the upper surface of the protrusions 73 on the z-axis positive side is located below the opening 70, and a step surface 74 is formed on the opening side of the front wall of the case 7.

[0039] When part of the capacitor unit is accommodated in the accommodation portion 71 of the case 7, the lower surface of the first bent portion 61 of the second insulating member 6 abuts against the stepped surface 74 on the upper surface of the protrusion 73, thereby positioning the second insulating member 6 with respect to the case 7. Here, the stepped surface 74 of the protrusion 73 corresponds to the "abutment portion" in this invention.

[0040] According to the first embodiment described above, a rib 56 is formed as an engaged portion on the peripheral wall portion 54 of the first insulating member 5, and an edge portion 65 as an engaging portion of the peripheral wall portion 63 of the second insulating member 6 abuts and engages with the rib 56, thereby enabling the second insulating member 6 to be positioned relative to the first insulating member 5. Positioning can be achieved using a reliable and simple engaging structure formed by the edge portion 65 and the rib 56, rather than a complex three-dimensional engaging structure. This eliminates the need for a complex structure for the mold used to process the insulating member, and the creation of joints on the case for positioning the insulating member, as was the case in the prior art, and allows the second insulating member 6 to be reliably positioned using the first insulating member 5.

[0041] Furthermore, a step surface 74 is formed on the upper surface of the protrusion 73 on the front wall 72 of the case 7, and the lower surface of the first bent portion 61 of the second insulating member 6 abuts against this step surface 74. This prevents the occurrence of joints that would otherwise occur due to the formation of notches in the case wall, as was the case in the past, and makes it possible to prevent cracks from occurring in the case 7 due to vibration, heat shock, etc.

[0042] Furthermore, by abutting the underside of the first bent portion 61 of the second insulating member 6 against the step surface 74 of the case 7, the second insulating member 6 can be positioned relative to the case 7 when part of the capacitor unit is accommodated in the accommodating portion 71 of the case 7, and the capacitor unit can be positioned when accommodated with a simple configuration.

[0043] The present invention is not limited to the above-described configuration, and various design modifications can be made within the scope of the claims.

[0044] For example, in the above embodiment, an example was described in which the edge portion 65 of the second insulating member 6 as the engaging portion engages with the rib 56 of the first insulating member 5 as the engaged portion, but the engagement structure of the engaging portion and the engaged portion is not limited to such a structure using an edge portion and a rib.

[0045] In the above embodiment, two ridges 73 are formed on the inner surface of the front wall 72 of the case 7, and a stepped surface 74 is formed on the upper surface of the ridges 73. However, one or three or more ridges may be formed to form one or three or more stepped surfaces. However, depending on the size (area of ​​the stepped surface) and position of the ridges, it is preferable to form two or more ridges.

[0046] Furthermore, the step surface 74 is not limited to being formed on the upper surface of the above-mentioned protrusion 73, but may have any configuration as long as it is formed on the wall surface of the case 7 so as to protrude toward the opening side and can be positioned by abutting the second insulating member 6 (first bent portion 61).

[0047] Furthermore, the third bus bar 4 (third terminal) is not limited to being used for ground connection of the inverter as described above, but may be any bus bar having a third polarity different from the first and second polarities.

[0048] The present invention is widely applicable to film capacitors having a capacitor element having a pair of end surface electrodes, a first terminal having a first polarity connected to one of the end surface electrodes of the capacitor element, and a second terminal having a second polarity connected to the other end surface electrode of the capacitor element. [Explanation of symbols]

[0049] 1...Film capacitor 2...First bus bar (first terminal) 3...Second bus bar (second terminal) 4...Third bus bar (third terminal) 5...First insulating member 6...Second insulating member 7. Case 8...Sealing resin 54...peripheral wall part 56…リブ(the tied part) 61 …First flexion 63 … Zhoubi section 65…Duanqi Department (Xiehe Department) 73 …protruding bar 74 …step surface (when connecting)

Claims

1. A film capacitor comprising: a capacitor element having a pair of end surface electrodes; a first terminal having a first polarity connected to one of the end surface electrodes of the capacitor element; and a second terminal having a second polarity connected to the other end surface electrode of the capacitor element, a first insulating member that insulates between the first terminal and the second terminal; a second insulating member that insulates between the first terminal or the second terminal and a third terminal having a third polarity different from the first and second polarities; A film capacitor characterized in that an engaging portion is provided on one of the first insulating member and the second insulating member, and an engaged portion that can engage with the engaging portion is provided on the other, and the members are positioned by engaging with each other.

2. Further comprising a case for accommodating the capacitor element, 2. The film capacitor according to claim 1, wherein the case is provided with a contact portion that contacts either the first insulating member or the second insulating member.

3. The case is formed of a bottomed housing with one side open, The film capacitor according to claim 2, characterized in that a stepped surface is formed on the side wall opening side of the bottomed housing, and the stepped surface abuts against either the first insulating member or the second insulating member as the abutment portion.

4. A film capacitor as described in any one of claims 1 to 3, characterized in that an outwardly protruding rib is formed on either the first insulating member or the second insulating member, and the rib abuts against the edge portion of the other insulating member, thereby restricting movement of the other insulating member.

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