Method for manufacturing a capacitor and capacitor

Abstract

This method for manufacturing a capacitor uses a capacitor element and a die. The capacitor element has: a first electrode; a second electrode provided on the opposite side of the first electrode; a first bus bar connected to the first electrode; and a second bus bar connected to the second electrode. The die has: a cavity for housing the capacitor element; a first fitting hole which is provided on the inner surface of the cavity and to which the first bus bar is fitted; and a second fitting hole which is provided on the inner surface of the cavity and to which the second bus bar is fitted. A space between the capacitor element and the inner surface of the cavity is injected and filled with a resin, in a state where the first bus bar is fitted to the first fitting hole, the second bus bar is fitted to the second fitting hole, and the capacitor element is held so as to be separated from the inner surface of the cavity.

Description

Technical Field

[0001] The present disclosure generally relates to a method for manufacturing a capacitor, and more particularly to a method for manufacturing a capacitor using a capacitor element and a mold.

Background Art

[0002] Patent Document 1 discloses a dry metallized film capacitor. This dry metallized film capacitor is formed by accommodating a capacitor element in a resin case, filling it with a thermosetting resin, and curing it. The above capacitor element is formed by overlapping and winding a single metallized film, spraying metallicon metal on both end faces to form electrode lead-out portions, and joining external lead wires to these electrode lead-out portions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the dry metallized film capacitor of Patent Document 1, the external lead wire has a key-shaped bend on the capacitor element side, a support plate is inserted into the L-shaped portion of the external lead wire, and it is accommodated and fixed in the resin case. Thereby, the lead pitch is unified regardless of the size of the element width of the capacitor element.

[0005] However, in the dry metallized film capacitor of Patent Document 1, the length of the shoulder portion of the external lead wire must be adjusted for each capacitor element. Furthermore, a support plate is required for each capacitor element, and the pitch of the holes in the support plate must be set to be equal to the lead pitch. Thus, in Patent Document 1, there is a problem that the work for making the lead pitch (bus bar pitch) constant becomes complicated if there are variations in the element width (dimension between electrodes) of the capacitor element.

[0006] An object of the present disclosure is to provide a method for manufacturing a capacitor that can easily make the bus bar pitch constant even if there are variations in the dimension between electrodes of the capacitor element.

Means for Solving the Problems

[0007] A method for manufacturing a capacitor according to one aspect of the present disclosure uses a capacitor element and a mold. The capacitor element has a first electrode, a second electrode provided on the opposite side of the first electrode, a first bus bar connected to the first electrode, and a second bus bar connected to the second electrode. The mold has a cavity for accommodating the capacitor element, a first fitting hole provided on the inner surface of the cavity and into which the first bus bar is fitted, and a second fitting hole provided on the inner surface of the cavity and into which the second bus bar is fitted. The first bus bar is fitted into the first fitting hole, the second bus bar is fitted into the second fitting hole, and resin is injected and filled into the space between the capacitor element and the inner surface of the cavity while the capacitor element is held in a state of being separated from the inner surface of the cavity.

Effects of the Invention

[0008] According to the present disclosure, even if there are variations in the dimension between electrodes of the capacitor element, the bus bar pitch can be easily made constant.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0010] 1. Overview In the method for manufacturing the capacitor 1 according to the present embodiment, as shown in FIG. 1, a capacitor element 2 and a mold 3 are used.

[0011] As shown in FIG. 2A, the capacitor element 2 has a first electrode 41, a second electrode 42, a first bus bar 51, and a second bus bar 52.

[0012] On the other hand, as shown in FIG. 1, the mold 3 has a cavity 6, a first fitting hole 71, and a second fitting hole 72. The cavity 6 houses the capacitor element 2. The first fitting hole 71 and the second fitting hole 72 are provided on the inner surface of the cavity 6.

[0013] Then, the first bus bar 51 of the capacitor element 2 is fitted into the first fitting hole 71 of the mold 3. Also, the second bus bar 52 of the capacitor element 2 is fitted into the second fitting hole 72 of the mold 3. As a result, the capacitor element 2 is held at a distance from the inner surface of the cavity 6. In this way, with the capacitor element 2 held, resin is injected and filled from the injection port 325 into the space between the capacitor element 2 and the inner surface of the cavity 6. As a result, a capacitor 1 in which the capacitor element 2 is sealed by the sealing portion 10 is obtained (see Fig. 2B).

[0014] As described above, in this embodiment, the first bus bar 51 is fitted into the first fitting hole 71, and the second bus bar 52 is fitted into the second fitting hole 72. Here, the distance (hole-to-hole pitch HP) between the first fitting hole 71 and the second fitting hole 72 is equal to the bus bar-to-bus bar pitch BP required for the capacitor 1 (see Fig. 6B). Therefore, even if there is variation in the bus bar-to-bus bar pitch bp of the capacitor element 2 before sealing (see Fig. 6A), this variation is reduced by fitting the first bus bar 51 into the first fitting hole 71 and the second bus bar 52 into the second fitting hole 72. That is, the bus bar-to-bus bar pitch bp can be corrected by the first fitting hole 71 and the second fitting hole 72. And after sealing, since the connection portions between the first bus bar 51 and the first electrode 41 and between the second bus bar 52 and the second electrode 42 are hardened by the sealing portion 10 (see Fig. 2B), the first bus bar 51 and the second bus bar 52 are held in appropriate positions even after becoming the capacitor 1. That is, the bus bar-to-bus bar pitch bp is within the allowable range of the bus bar-to-bus bar pitch BP.

[0015] Moreover, in this embodiment, there is no need for complicated operations such as adjusting the length of the shoulder portion of the external lead wire for each capacitor element as in Patent Document 1 or preparing a support plate with a hole pitch set for each capacitor element.

[0016] Therefore, according to the manufacturing method of the capacitor 1 according to this embodiment, even if there is variation in the electrode-to-electrode dimension L of the capacitor element 2 (see Fig. 6A), the bus bar-to-bus bar pitch bp can be easily made constant (bus bar-to-bus bar pitch BP).

[0017] 2. Details Hereinafter, the manufacturing method of the capacitor 1 according to the present embodiment will be described in detail with reference to the drawings. For convenience of explanation, arrows indicating the vertical direction, the horizontal direction, and the front-rear direction are shown in the drawings, but these arrows are not accompanied by an entity. These directions are merely examples and are not intended to limit the directions during the manufacturing and use of the capacitor 1.

[0018] As shown in FIG. 1, in the manufacturing method of the capacitor 1 according to the present embodiment, a capacitor element 2 and a mold 3 are used. Hereinafter, first, the capacitor element 2 will be described. Next, the capacitor 1 obtained by using the capacitor element 2 will be described. Next, the mold 3 used for manufacturing the capacitor 1 will be described. Thereafter, the method of manufacturing the capacitor 1 using the capacitor element 2 and the mold 3 will be described.

[0019] <Capacitor Element> First, the capacitor element 2 will be described. FIG. 2A shows the capacitor element 2. The capacitor element 2 is formed by stacking two metallized films obtained by vapor-depositing a metal such as aluminum on a dielectric film, winding the stacked metallized films, and pressing them flat (pressing in the front-rear direction in FIG. 2A). The shape of the cross-section (cross-section viewed from the left-right direction) of the capacitor element 2 is a rounded rectangle.

[0020] The capacitor element 2 has a columnar shape extending in the left-right direction. The capacitor element 2 includes a first electrode 41, a second electrode 42, a first bus bar 51, and a second bus bar 52. In the present embodiment, the capacitor element 2 further includes an elastic conductor member 9.

[0021] The first electrode 41 is provided in a layered manner on the left end surface of the capacitor element 2. The first electrode 41 is formed of a metal such as zinc, for example, by metallicon (metal spraying method).

[0022] The second electrode 42 is provided on the opposite side of the first electrode 41. That is, the second electrode 42 is provided in a layered manner on the right end face of the capacitor element 2. The second electrode 42 is also formed in the same manner as the first electrode 41.

[0023] Here, as shown in FIG. 6A, the inter-electrode dimension L is defined in the left-right direction as the length between the surface facing the left side of the first electrode 41 and the surface facing the right side of the second electrode 42. Generally, when manufacturing a plurality of capacitor elements 2, the inter-electrode dimensions L of these capacitor elements 2 may vary.

[0024] The first bus bar 51 is connected to the first electrode 41. In the present embodiment, the first bus bar 51 is connected to the first electrode 41 via the elastic conductor member 9. The first bus bar 51 protrudes upward from the capacitor element 2. The first bus bar 51 is a conductor member. The material of the first bus bar 51 is not particularly limited as long as it is a conductive material, and includes, for example, copper and copper alloys. The first bus bar 51 has a main body portion 511 and a protruding portion 512.

[0025] The main body portion 511 is connected to the elastic conductor member 9. The main body portion 511 is a plate-like member extending in the vertical direction. The main body portion 511 is disposed substantially parallel to the surface facing the left side of the first electrode 41.

[0026] The protruding portion 512 protrudes rightward from the front side of the upper portion of the main body portion 511. The protruding portion 512 has a flat plate shape orthogonal to the main body portion 511.

[0027] In the present embodiment, the elastic conductor member 9 is interposed between the first electrode 41 and the first bus bar 51. The elastic conductor member 9 is not particularly limited, and examples include a leaf spring (thin plate spring). The elastic conductor member 9 can be formed, for example, by bending a single elongated thin plate. In the present embodiment, the elastic conductor member 9 has a first flat portion 91, a second flat portion 92, and an inclined surface portion 93.

[0028] The first planar portion 91 is a plate-shaped member that is slightly smaller than the main body portion 511 of the first bus bar 51 and extends in the vertical direction. The first planar portion 91 is connected to the first bus bar 51. Specifically, the upper end portion of the first planar portion 91 and the lower end portion of the main body portion 511 of the first bus bar 51 are connected. The connection between the first planar portion 91 and the first bus bar 51 is performed by welding or the like. Note that welding includes, for example, laser welding and ultrasonic welding.

[0029] The second planar portion 92 has substantially the same shape as the first planar portion 91. The second planar portion 92 is located below and to the right of the first planar portion 91 and is arranged parallel to the first planar portion 91. The second planar portion 92 is directly connected to the first electrode 41. The connection between the second planar portion 92 and the first electrode 41 is also performed by welding or the like.

[0030] The inclined surface portion 93 is a portion that connects the first planar portion 91 and the second planar portion 92. The inclined surface portion 93 inclines from the lower end of the first planar portion 91 toward the lower right and reaches the upper end of the second planar portion 92.

[0031] As described above, the first electrode 41 and the first bus bar 51 are indirectly connected via the elastic conductor member 9. The elastic conductor member 9 is a conductor member that can be elastically deformed in the direction (left-right direction) connecting the first electrode 41 and the second electrode 42. When a rightward force is applied to the first bus bar 51, the elastic conductor member 9 elastically deforms, causing the first bus bar 51 to move to the right from its original position. Conversely, when a leftward force is applied to the first bus bar 51, the elastic conductor member 9 elastically deforms, causing the first bus bar 51 to move to the left from its original position. Furthermore, since the elastic conductor member 9 has conductivity, the first electrode 41 and the first bus bar 51 are electrically connected via the elastic conductor member 9.

[0032] The second bus bar 52 is connected to the second electrode 42. In the present embodiment, the second electrode 42 and the second bus bar 52 are directly connected. The second bus bar 52 is also a conductor member similar to the first bus bar 51. Thereby, the second electrode 42 and the second bus bar 52 are electrically connected. The second bus bar 52 protrudes in the same direction (upward) as the first bus bar 51. The second bus bar 52 has a main body portion 521 and a protruding portion 522.

[0033] The main body portion 521 is directly connected to the second electrode 42. The main body portion 521 is a plate-like member extending in the vertical direction. The main body portion 521 is arranged substantially parallel to the surface facing the right side of the second electrode 42.

[0034] The protruding portion 522 protrudes leftward from the front side of the upper part of the main body portion 521. The protruding portion 522 has a flat plate shape orthogonal to the main body portion 521.

[0035] The main body portion 511 of the first bus bar 51 and the main body portion 521 of the second bus bar 52 face each other. The main body portion 511 of the first bus bar 51 and the main body portion 521 of the second bus bar 52 are arranged substantially parallel to each other.

[0036] The protruding portion 512 of the first bus bar 51 and the protruding portion 522 of the second bus bar 52 are arranged in the same plane extending in the vertical and horizontal directions. In the vertical direction, the position of the protruding portion 512 of the first bus bar 51 and the position of the protruding portion 522 of the second bus bar 52 are the same. In particular, the positions of the lower end edges of the protruding portion 512 and the protruding portion 522 are the same.

[0037] Here, as shown in FIG. 6A, the bus bar pitch bp is defined, in the left - right direction, as the length between the center of the thickness of the main body portion 511 of the first bus bar 51 and the center of the thickness of the main body portion 521 of the second bus bar 52. Specifically, the bus bar pitch bp required for the capacitor 1 is referred to as the "bus bar pitch BP". That is, the bus bar pitch BP is the reference value. As described above, when manufacturing a plurality of capacitor elements 2, the electrode - to - electrode dimension L of these capacitor elements 2 may vary, and thus the bus bar pitch bp may also vary under this influence. The bus bar pitch bp is required to be within the allowable range of the bus bar pitch BP. However, generally, the bus bar pitch bp may fall outside the allowable range of the bus bar pitch BP. As will be described later, according to this embodiment, it is possible to easily bring the bus bar pitch bp within the allowable range of the bus bar pitch BP. Note that the tolerance is set as appropriate.

[0038] <Capacitor> Next, the capacitor 1 will be described. The capacitor 1 is shown in FIG. 2B. The capacitor 1 is obtained by using the above - described capacitor element 2. The capacitor 1 is a so - called case - less capacitor. That is, the capacitor 1 does not require a case such as a resin case described in Patent Document 1. Therefore, the weight can be reduced by at least the amount corresponding to the absence of the case.

[0039] In the capacitor 1, the entire capacitor element 2 is covered and sealed by the sealing portion 10. Thereby, it is possible to suppress the intrusion of moisture and the like into the interior of the capacitor element 2. The sealing portion 10 is a cured product of a resin such as a thermosetting resin. In this embodiment, the outer shape of the sealing portion 10 is in the shape of a rectangular parallelepiped. The first bus bar 51 (a part of the main body portion 511 and the protruding portion 512) and the second bus bar 52 (a part of the main body portion 521 and the protruding portion 522) protrude from the sealing portion 10 in the same direction (upward).

[0040] <Mold> Next, the mold 3 used to manufacture the capacitor 1 will be described. The mold 3 is shown in FIGS. 1 and 5. The mold 3 has a cavity 6 (see FIG. 1). The cavity 6 is formed when the mold is clamped. The cavity 6 is a space for accommodating the capacitor element 2. The shape of the cavity 6 is the same as the outer shape of the sealing portion 10 of the capacitor 1. That is, in the present embodiment, the cavity 6 is a rectangular parallelepiped-shaped space. When the capacitor element 2 is accommodated in the cavity 6, there is a gap between the outer surface of the capacitor element 2 and the inner surface of the cavity 6. Since resin is injected into this gap, the entire capacitor element 2 will be covered and sealed with resin.

[0041] In the present embodiment, the mold 3 has a mold body 30 and a holding mold 34. When the mold is clamped, the mold 3 is in the shape of a rectangular parallelepiped (see FIG. 1). When the mold is clamped, the mold body 30 is located outside, and the holding mold 34 is located inside the mold body 30. The mold body 30 includes a first mold 31, a second mold 32, and a third mold 33.

[0042] The first mold 31 is a mold located in the upper front when the mold is clamped (see FIG. 1). The outer shape of the first mold 31 is in the shape of a rectangular parallelepiped. As shown in FIG. 4, the first mold 31 has a first recess 311, a second recess 312, a plurality (two in the present embodiment) of bus bar accommodating portions 313, and a plurality (two in the present embodiment) of bolt holes 314.

[0043] The first recess 311 is a rectangular parallelepiped-shaped space extending in the left-right direction. The first recess 311 opens below and behind the first mold 31.

[0044] The second recess 312 is a space that is slightly smaller than the first recess 311 and has a rectangular parallelepiped shape. That is, the length of the second recess 312 in the front-rear direction is shorter than the length of the first recess 311 in the front-rear direction. The length of the second recess 312 in the left-right direction is shorter than the length of the first recess 311 in the left-right direction. In the left-right direction, the second recess 312 is located at the center of the first recess 311. The second recess 312 is located above the first recess 311. The second recess 312 is continuous with the first recess 311. The second recess 312 opens downward and rearward of the first mold 31.

[0045] The two bus bar accommodating portions 313 are spaces in which the first bus bar 51 and the second bus bar 52 are accommodated during mold clamping. The bus bar accommodating portion 313 is a space that is slightly smaller than the first recess 311 and has a rectangular parallelepiped shape. The bus bar accommodating portion 313 is located above the first recess 311. The bus bar accommodating portion 313 is continuous with the first recess 311. The bus bar accommodating portion 313 opens downward of the first mold 31. The two bus bar accommodating portions 313 are arranged side by side in the left-right direction. The two bus bar accommodating portions 313 are located in front of the second recess 312.

[0046] The two bolt holes 314 are used when attaching the holding mold 34 to the first mold 31. The two bolt holes 314 are provided on the surface facing rearward within the second recess 312. The two bolt holes 314 are arranged side by side in the left-right direction. The two bolt holes 314 are provided in the front-rear direction. The two bolt holes 314 are non-through holes.

[0047] The second mold 32 is a mold that is located at the lower front during mold clamping (see FIG. 1). The outer shape of the second mold 32 has a rectangular parallelepiped shape. As shown in FIG. 5, the second mold 32 has a front wall portion 321, a left wall portion 322, a right wall portion 323, a lower wall portion 324, and an injection port 325.

[0048] The front wall portion 321 is located in front of the second mold 32. The front wall portion 321 is a wall in the shape of a rectangular plate extending in the vertical and horizontal directions. The front wall portion 321 has a front forming surface 66. The front forming surface 66 is a surface facing the rear of the front wall portion 321. The front forming surface 66 forms a part of the inner surface of the cavity 6. That is, the front forming surface 66 is a surface for forming the front surface of the sealing portion 10 of the capacitor 1.

[0049] The left wall portion 322 is located on the left side of the second mold 32. The left wall portion 322 is a wall in the shape of a rectangular plate extending in the vertical and front-rear directions. The front end portion of the left wall portion 322 is connected to the left end portion of the front wall portion 321. The left wall portion 322 has a left forming surface 64. The left forming surface 64 is a surface facing the right side of the left wall portion 322. The left forming surface 64 forms a part of the inner surface of the cavity 6. That is, the left forming surface 64 is a surface for forming the left side surface of the sealing portion 10 of the capacitor 1.

[0050] The right wall portion 323 faces the left wall portion 322. The right wall portion 323 is located on the right side of the second mold 32. The right wall portion 323 is a wall in the shape of a rectangular plate extending in the vertical and front-rear directions. The front end portion of the right wall portion 323 is connected to the right end portion of the front wall portion 321. The right wall portion 323 has a right forming surface 65. The right forming surface 65 is a surface facing the left side of the right wall portion 323. The right forming surface 65 forms a part of the inner surface of the cavity 6. That is, the right forming surface 65 is a surface for forming the right side surface of the sealing portion 10 of the capacitor 1. The right forming surface 65 faces the left forming surface 64.

[0051] The lower wall portion 324 is located below the second mold 32. The lower wall portion 324 is a wall in the shape of a rectangular plate extending in the horizontal and front-rear directions. The front end portion of the lower wall portion 324 is connected to the lower end portion of the front wall portion 321. The left end portion of the lower wall portion 324 is connected to the lower end portion of the left wall portion 322. The right end portion of the lower wall portion 324 is connected to the lower end portion of the right wall portion 323. The lower wall portion 324 has a lower forming surface 63. The lower forming surface 63 is a surface facing the upper side of the lower wall portion 324. The lower forming surface 63 forms a part of the inner surface of the cavity 6. That is, the lower forming surface 63 is a surface for forming the lower surface of the sealing portion 10 of the capacitor 1.

[0052] The upper end surfaces of the front wall portion 321, the left wall portion 322, and the right wall portion 323 are flush. The rear end surfaces of the left wall portion 322, the right wall portion 323, and the lower wall portion 324 are flush.

[0053] The injection port 325 is an opening for injecting resin from the outside of the mold 3 into the cavity 6 during mold clamping. The injection port 325 communicates the outside of the mold 3 and the inside of the cavity 6 during mold clamping. In the present embodiment, the injection port 325 is provided in the front wall portion 321. Specifically, the injection port 325 is provided by cutting out a semicircular part of the upper end surface of the front wall portion 321.

[0054] The third mold 33 is a mold located rearward during mold clamping (see FIG. 1). During mold clamping, the third mold 33 contacts the rear surface of the first mold 31, the rear surface of the holding mold 34, the rear surfaces of the left wall portion 322, the right wall portion 323, and the lower wall portion 324 of the second mold 32. The third mold 33 has a rectangular plate shape extending in the vertical and horizontal directions. The third mold 33 has a rear molding surface 67. The rear molding surface 67 is a surface facing forward of the third mold 33. The rear molding surface 67 becomes a part of the inner surface of the cavity 6. That is, the rear molding surface 67 is a surface for molding the rear surface of the sealing portion 10 of the capacitor 1. During mold clamping, the rear molding surface 67 faces the front molding surface 66.

[0055] FIG. 4 shows the holding mold 34. The holding mold 34 is a mold for holding the capacitor element 2. The holding mold 34 is attached to the first mold 31 during mold clamping (see FIGS. 1 and 5). The holding mold 34 can be removed from the first mold 31 during mold opening (see FIG. 4). In this way, the holding mold 34 holds the capacitor element 2 and is detachable from the mold body 30 (the first mold 31 in the present embodiment). As shown in FIG. 3, the holding mold 34 includes a first holding member 341 and a second holding member 342.

[0056] The first holding member 341 is a rectangular parallelepiped-shaped member extending in the left-right direction. The lengths of the first holding member 341 in the vertical and left-right directions are equal to the lengths of the first recess 311 of the first mold 31 in the vertical and left-right directions, respectively. The first holding member 341 has an upper molding surface 61, a first fitting hole 71, a second fitting hole 72, and a plurality (two in this embodiment) of bolt holes 343.

[0057] The upper molding surface 61 is the lower surface of the first holding member 341. The upper molding surface 61 forms a part of the inner surface of the cavity 6. That is, the upper molding surface 61 is a surface for molding a part of the upper surface of the sealing portion 10 of the capacitor 1.

[0058] The first fitting hole 71 is a hole for fitting the first bus bar 51. In this embodiment, the first fitting hole 71 is formed in a slit shape. The first fitting hole 71 penetrates in the vertical direction of the first holding member 341. That is, the first fitting hole 71 is provided on the inner surface of the cavity 6 (the upper molding surface 61 in this embodiment). Further, the first fitting hole 71 opens at the rear surface of the first holding member 341. The opening at the rear surface is closed when the second holding member 342 is attached to the first holding member 341. The length of the first fitting hole 71 in the front-rear direction is equal to the width (length in the front-rear direction) of the main body portion 511 of the first bus bar 51. The width (length in the left-right direction) of the first fitting hole 71 is equal to the thickness (length in the left-right direction) of the main body portion 511 of the first bus bar 51.

[0059] The second fitting hole 72 is a hole for fitting the second bus bar 52. The second fitting hole 72 is formed in the same manner as the first fitting hole 71. That is, the second fitting hole 72 is also provided on the inner surface of the cavity 6 (the upper molding surface 61 in this embodiment). The length of the second fitting hole 72 in the front-rear direction is equal to the width (length in the front-rear direction) of the main body portion 521 of the second bus bar 52. The width (length in the left-right direction) of the second fitting hole 72 is equal to the thickness (length in the left-right direction) of the main body portion 521 of the second bus bar 52.

[0060] Here, as shown in FIG. 6B, the hole pitch HP is defined in the left-right direction as the length between the center of the first fitting hole 71 and the center of the second fitting hole 72. The hole pitch HP is a predetermined interval. That is, the hole pitch HP is equal to the bus bar pitch BP required for the capacitor 1.

[0061] The two bolt holes 343 are used when attaching the second holding member 342 to the first holding member 341. The two bolt holes 343 are provided on the rear surface of the first holding member 341. The two bolt holes 343 are located between the first fitting hole 71 and the second fitting hole 72 in the left-right direction. The two bolt holes 343 are arranged side by side in the left-right direction. The two bolt holes 343 are provided in the front-rear direction. The two bolt holes 343 are non-through holes.

[0062] The second holding member 342 is detachable from the first holding member 341. When attaching the second holding member 342 to the first holding member 341, the second holding member 342 is located behind the first holding member 341. The second holding member 342 has a main body portion 344, a convex portion 345, a plurality (two in this embodiment) of first bolt insertion holes 346, and a plurality (two in this embodiment) of second bolt insertion holes 347.

[0063] The main body portion 344 is a rectangular parallelepiped member extending in the left-right direction. The lengths of the main body portion 344 in the up-down direction and the left-right direction are respectively equal to the lengths of the first recess 311 of the first mold 31 in the up-down direction and the left-right direction. The front surface of the main body portion 344 can be in almost contact with the rear surface of the first holding member 341 without a gap. Thereby, the first fitting hole 71 and the second fitting hole 72 can be made into holes penetrating in the up-down direction.

[0064] The sum of the lengths of the first holding member 341 in the front-rear direction and the length of the main body portion 344 of the second holding member 342 in the front-rear direction is equal to the length of the first recess 311 of the first mold 31 in the front-rear direction. Therefore, the first holding member 341 and the main body portion 344 of the second holding member 342 can be fitted into the first recess 311 of the first mold 31.

[0065] The body portion 344 has an upper molding surface 62. The upper molding surface 62 is the lower surface of the body portion 344 of the second holding member 342. The upper molding surface 62 forms a part of the inner surface of the cavity 6. That is, the upper molding surface 62 is a surface for molding a part of the upper surface of the sealing portion 10 of the capacitor 1. Specifically, when the first holding member 341 and the second holding member 342 are integrated, the upper molding surface 61 of the first holding member 341 and the upper molding surface 62 of the second holding member 342 are flush. The upper surface of the sealing portion 10 of the capacitor 1 is molded by both the upper molding surface 61 and the upper molding surface 62.

[0066] Here, as shown in FIG. 6B, the thickness T (the length in the vertical direction) of the body portions 344 of the first holding member 341 and the second holding member 342 is shorter than the length H in the vertical direction between the lower end edges of the protruding portions 512 of the first bus bar 51 and the protruding portions 522 of the second bus bar 52 and the uppermost portion of the capacitor element 2 (T < H). Thereby, a gap can be secured between the upper molding surfaces 61 and 62 of the holding die 34 and the uppermost portion of the capacitor element 2. Therefore, the gap can be filled with resin.

[0067] The convex portion 345 protrudes upward from the upper surface of the body portion 344. The convex portion 345 is a portion that is slightly smaller than the body portion 344 and has a rectangular parallelepiped shape. In the left - right direction, the convex portion 345 is located at the center of the body portion 344. The lengths of the convex portion 345 in the vertical, left - right, and front - rear directions are equal to the lengths of the second recess 312 of the first die 31 in the vertical, left - right, and front - rear directions, respectively. Therefore, the convex portion 345 can be fitted into the second recess 312 of the first die 31.

[0068] The two first bolt insertion holes 346 are used when attaching the second holding member 342 to the first holding member 341. The two first bolt insertion holes 346 are through - holes. Specifically, the two first bolt insertion holes 346 penetrate the body portion 344 of the second holding member 342 in the front - rear direction. The two first bolt insertion holes 346 are arranged side by side in the left - right direction.

[0069] The two second bolt insertion holes 347 are used when attaching the holding die 34 to the first die 31. The two second bolt insertion holes 347 are through holes. Specifically, the two second bolt insertion holes 347 penetrate the convex portion 345 of the second holding member 342 in the front-rear direction. The two second bolt insertion holes 347 are arranged side by side in the left-right direction.

[0070] <Method for manufacturing a capacitor> Next, a method for manufacturing the capacitor 1 will be described. In the method for manufacturing the capacitor 1 according to the present embodiment, the above-described capacitor element 2 and the die 3 are used.

[0071] First, as shown in FIG. 3, the first bus bar 51 is fitted into the first fitting hole 71, and the second bus bar 52 is fitted into the second fitting hole 72. Specifically, from the rear of the first holding member 341, the main body portion 511 of the first bus bar 51 of the capacitor element 2 is inserted into the first fitting hole 71 of the first holding member 341, and the main body portion 521 of the second bus bar 52 of the capacitor element 2 is inserted into the second fitting hole 72 of the first holding member 341. The protruding portion 512 of the first bus bar 51 and the protruding portion 522 of the second bus bar 52 are arranged above the first holding member 341.

[0072] At this time, if the bus bar pitch bp is larger than the hole pitch HP, an inward force is applied to the first bus bar 51 and the second bus bar 52 to narrow the bus bar pitch bp until it becomes equal to the hole pitch HP. Since the elastic conductor member 9 is interposed between the first bus bar 51 and the first electrode 41, a rightward force may be applied to the first bus bar 51 to narrow the bus bar pitch bp. In this state, the main body portion 511 of the first bus bar 51 is inserted into the first fitting hole 71, and the main body portion 521 of the second bus bar 52 is inserted into the second fitting hole 72.

[0073] Conversely, if the bus bar pitch bp is smaller than the hole pitch HP, an outward force is applied to the first bus bar 51 and the second bus bar 52 to widen the bus bar pitch bp until it becomes equal to the hole pitch HP. Since the elastic conductor member 9 is interposed between the first bus bar 51 and the first electrode 41, an outward force may be applied to the first bus bar 51 to widen the bus bar pitch bp. In this state, the main body portion 511 of the first bus bar 51 is inserted into the first fitting hole 71, and the main body portion 521 of the second bus bar 52 is inserted into the second fitting hole 72.

[0074] Next, the front surface of the main body portion 344 of the second holding member 342 is brought into contact with the rear surface of the first holding member 341. In this state, two first bolts 81 are screwed in sequence from the rear to the front into the two first bolt insertion holes 346 of the second holding member 342 and the two bolt holes 343 of the first holding member 341. Thereby, the first holding member 341 and the second holding member 342 are integrated to form the holding die 34. In this way, the holding die 34 can hold the capacitor element 2 (see FIG. 4).

[0075] At this time, since the protruding portions 512 of the first bus bar 51 and the protruding portions 522 of the second bus bar 52 are arranged above the first holding member 341, even if the capacitor element 2 is pulled downward, the protruding portions 512 and 522 are caught on the upper surface of the holding die 34 (the first holding member 341 in this embodiment) and function as stoppers, so that the holding of the capacitor element 2 by the holding die 34 is not released. That is, the protruding portions 512 and 522 prevent the capacitor element 2 from coming out of the holding die 34.

[0076] Next, as shown in FIG. 4, a holding die 34 holding the capacitor element 2 is attached to a die body 30 (the first die 31 in this embodiment). Specifically, the first die 31 and the holding die 34 are brought close to each other along the vertical direction and fitted together. At this time, a first bus bar 51 and a second bus bar 52 protruding upward from the holding die 34 are respectively received in two bus bar accommodating portions 313 of the first die 31. Specifically, portions including the protruding portions 512 of the first bus bar 51 and portions including the protruding portions 522 of the second bus bar 52 are received in the two bus bar accommodating portions 313. The main body portions 344 of the first holding member 341 and the second holding member 342 are fitted into the first recess 311 of the first die 31. The convex portion 345 of the second holding member 342 is fitted into the second recess 312 of the first die 31. In this state, two second bolts 82 are screwed from the rear to the front into two second bolt insertion holes 347 of the second holding member 342 and two bolt holes 314 of the first die 31 in sequence. Thereby, the holding die 34 can be attached to the first die 31 (see FIG. 5). The rear surface of the first die 31 and the rear surface of the holding die 34 (the second holding member 342 in this embodiment) are flush.

[0077] Next, as shown in FIG. 5, using the first die 31 to which the holding die 34 is attached, the second die 32, and the third die 33, the die 3 is clamped. FIG. 1 shows the die 3 after clamping. By clamping, a cavity 6 is formed inside the die 3. The cavity 6 is a space surrounded by an upper molding surface 61, an upper molding surface 62, a lower molding surface 63, a left molding surface 64, a right molding surface 65, a front molding surface 66, and a rear molding surface 67. That is, the inner surface of the cavity 6 is the upper molding surface 61, the upper molding surface 62, the lower molding surface 63, the left molding surface 64, the right molding surface 65, the front molding surface 66, and the rear molding surface 67 (see FIGS. 1 and 5).

[0078] The capacitor element 2 is held spaced apart from the inner surface of the cavity 6. That is, a space is formed between the outer surface of the capacitor element 2 and the inner surface of the cavity 6. In this state, resin is injected and filled into the space between the capacitor element 2 and the inner surface of the cavity 6. That is, the resin is injected into the die 3 from the injection port 325 of the die 3 into the inside of the die 3.

[0079] Here, the main body 511 of the first bus bar 51 fits into the first fitting hole 71 with almost no gap, and the main body 521 of the second bus bar 52 fits into the second fitting hole 72 with almost no gap. Therefore, when injecting resin into the cavity 6 of the resin, it is possible to suppress the resin from passing through the first fitting hole 71 and the second fitting hole 72 and entering the upper part of the holding mold 34.

[0080] The resin has electrical insulation. The resin is not particularly limited as long as it is an electrical insulating material. For example, it includes an epoxy resin. After the resin is cured and the mold 3 is opened, the capacitor 1 as shown in FIG. 2B can be obtained.

[0081] <Function and Effect> In the method for manufacturing the capacitor 1 according to the present embodiment, the first bus bar 51 is fitted into the first fitting hole 71, and the second bus bar 52 is fitted into the second fitting hole 72. Here, the distance (hole-to-hole pitch HP) between the first fitting hole 71 and the second fitting hole 72 is equal to the bus bar-to-bus bar pitch BP required for the capacitor 1 (see FIG. 6B). Therefore, even if there is a variation in the bus bar-to-bus bar pitch bp of the capacitor element 2 before sealing, this variation is reduced by fitting the first bus bar 51 into the first fitting hole 71 and the second bus bar 52 into the second fitting hole 72. That is, it can be corrected by the first fitting hole 71 and the second fitting hole 72 of the holding mold 34 so that if the bus bar-to-bus bar pitch bp is narrower than the bus bar-to-bus bar pitch BP, it becomes wider, and conversely, if it is wider, it becomes narrower. And in this way, with the first bus bar 51 and the second bus bar 52 held in appropriate positions, the connection portion between the first bus bar 51 and the first electrode 41 and the connection portion between the second bus bar 52 and the second electrode 42 are solidified by the sealing portion 10. Therefore, even after the capacitor 1 is formed, the first bus bar 51 and the second bus bar 52 are held in appropriate positions. That is, the bus bar-to-bus bar pitch bp is within the allowable range of the bus bar-to-bus bar pitch BP.

[0082] In addition, since the first fitting hole 71 and the second fitting hole 72 for correcting the bus bar pitch bp are provided in the mold 3 (the holding mold 34 in this embodiment), there is no need for complicated operations such as adjusting the length of the shoulder of the external lead wire for each capacitor element or preparing a support plate with a hole pitch set for each capacitor element as in Patent Document 1. That is, in this embodiment, basically, with one mold 3, a plurality of capacitors 1 with the same bus bar pitch BP can be manufactured.

[0083] As described above, according to the manufacturing method of the capacitor 1 according to this embodiment, even if there is variation in the inter-electrode dimension L of the capacitor element 2, the bus bar pitch bp can be easily made constant (bus bar pitch BP).

[0084] In addition, in this embodiment, since the holding mold 34 is detachable from the mold body 30 (the first mold 31), the capacitor element 2 can be held on the holding mold 34 with the holding mold 34 removed from the mold body 30. Therefore, the operation of holding the capacitor element 2 on the holding mold 34 becomes easy.

[0085] In addition, in this embodiment, since the elastic conductor member 9 is interposed between the first electrode 41 and the first bus bar 51, compared with the case where the elastic conductor member 9 is not interposed, stress is less likely to concentrate on the connection portion between the first electrode 41 and the first bus bar 51. Further, due to the elastic deformation of the elastic conductor member 9 in the left-right direction, it becomes easier to move the first bus bar 51 to a position separated from the position of the second bus bar 52 by the bus bar pitch BP. Therefore, it becomes easier to make the bus bar pitch bp more constant (bus bar pitch BP).

[0086] In addition, since the position of the second bus bar 52 can be fixed and the position of the first bus bar 51 can be moved, even if the elastic conductor member 9 is not interposed between the second electrode 42 and the second bus bar 52, stress is less likely to concentrate on the connection portion between the second electrode 42 and the second bus bar 52. Therefore, disconnection between the first electrode 41 and the first bus bar 51 and between the second electrode 42 and the second bus bar 52 can be suppressed. From the above, the elastic conductor member 9 may be interposed between at least one of the first electrode 41 and the first bus bar 51 and between the second electrode 42 and the second bus bar 52.

[0087] 3. Modification In this embodiment, the case where the capacitor element 2 is a wound capacitor element has been described, but the capacitor element 2 may be a multilayer capacitor element.

[0088] In this embodiment, the elastic conductor member 9 is interposed between the first electrode 41 and the first bus bar 51, but it may be interposed between the second electrode 42 and the second bus bar 52. That is, preferably, the elastic conductor member 9 is interposed between at least one of the first electrode 41 and the first bus bar 51 and between the second electrode 42 and the second bus bar 52.

[0089] In this embodiment, the outer shape of the sealing portion 10 of the capacitor 1 is rectangular parallelepiped, but as long as the entire capacitor element 2 is sealed, it may have a shape other than rectangular parallelepiped. Therefore, the shape of the cavity 6 of the mold 3 is not particularly limited. The sealing portion 10 of the capacitor element 2 may be coated with an appropriate gas barrier film. Thereby, the intrusion of moisture and the like into the capacitor element 2 can be further suppressed.

[0090] In this embodiment, when the mold 3 is closed, the outer shape of the mold 3 is rectangular parallelepiped, but it may have a shape other than rectangular parallelepiped.

[0091] The number of divisions of the mold 3 is not particularly limited. That is, the number of divisions of the mold body 30 and the number of divisions of the holding mold 34 are not limited.

[0092] The holding mold 34 does not necessarily need to be detachable from the mold body 30. That is, the holding mold 34 may be integrated with the mold body 30.

[0093] If the injection port 325 communicates the outside of the mold 3 with the inside of the cavity 6 during mold clamping, the position of the injection port 325 in the mold 3 is not particularly limited.

[0094] The air vent (gas vent) is appropriately provided in the mold 3.

[0095] 4. Embodiments As is clear from the above-described embodiments and modifications, the present disclosure includes the following embodiments. Hereinafter, for the sole purpose of clarifying the correspondence with the embodiments, reference numerals are given in parentheses.

[0096] A first embodiment is a method for manufacturing a capacitor (1), which uses a capacitor element (2) and a mold (3). The capacitor element (2) includes a first electrode (41), a second electrode (42) provided on the side opposite to the first electrode (41), a first bus bar (51) connected to the first electrode (41), and a second bus bar (52) connected to the second electrode (42). The mold (3) includes a cavity (6) for accommodating the capacitor element (2), a first fitting hole (71) provided on the inner surface of the cavity (6) into which the first bus bar (51) is fitted, and a second fitting hole (72) provided on the inner surface of the cavity (6) into which the second bus bar (52) is fitted. The first bus bar (51) is fitted into the first fitting hole (71), the second bus bar (52) is fitted into the second fitting hole (72), and resin is injected and filled into the space between the capacitor element (2) and the inner surface of the cavity (6) while the capacitor element (2) is held in a state of being spaced apart from the inner surface of the cavity (6).

[0097] According to this embodiment, even if there is variation in the inter-electrode dimensions of the capacitor element (2), the bus bar pitch can be easily made constant.

[0098] The second aspect is a method for manufacturing the capacitor (1) based on the first aspect. In the second aspect, the mold (3) includes a mold body (30) and a holding mold (34) that holds the capacitor element (2) and is detachable from the mold body (30). The holding mold (34) has the first fitting hole (71) and the second fitting hole (72).

[0099] According to this aspect, the operation of holding the capacitor element (2) in the holding mold (34) becomes easier.

[0100] The third aspect is a method for manufacturing the capacitor (1) based on the first or second aspect. In the third aspect, the capacitor element (2) further includes an elastic conductor member (9) that is elastically deformable in the direction connecting the first electrode (41) and the second electrode (42). The elastic conductor member (9) is interposed between at least one of the first electrode (41) and the first bus bar (51) and between the second electrode (42) and the second bus bar (52).

[0101] According to this aspect, it becomes easier to make the bus bar pitch more uniform. Disconnection between the first electrode (41) and the first bus bar (51) and between the second electrode (42) and the second bus bar (52) can be suppressed.

Explanation of Reference Numerals

[0102] 1 Capacitor 2 Capacitor element 3 Mold 30 Mold body 34 Holding mold 41 First electrode 42 Second electrode 51 First bus bar 52 Second bus bar 6 Cavity 71 First fitting hole 72 Second fitting hole 9 Elastic conductor member

Claims

1. A capacitor element having a first electrode, a second electrode provided on the opposite side of the first electrode, an elastic conductor member that entirely faces the first electrode and is elastically deformable in a direction connecting the first electrode and the second electrode, a first bus bar connected to the first electrode via the elastic conductor member, and a second bus bar connected to the second electrode; A mold having a cavity that houses the capacitor element, a first fitting hole provided on the inner surface of the cavity into which the first bus bar is fitted, and a second fitting hole provided on the inner surface of the cavity into which the second bus bar is fitted, is used. The first bus bar is fitted into the first fitting hole, the second bus bar is fitted into the second fitting hole, and resin is injected and filled into the space between the capacitor element and the inner surface of the cavity while the capacitor element is held in a state of being separated from the inner surface of the cavity. A method for manufacturing a capacitor.

2. The mold has a mold body and a holding mold that holds the capacitor element and is detachable from the mold body. The holding mold has the first fitting hole and the second fitting hole. The method for manufacturing a capacitor according to Claim 1.

3. The elastic conductor member is a first elastic conductor member. The capacitor element further has a second elastic conductor member that is elastically deformable in a direction connecting the first electrode and the second electrode. The second elastic conductor member is interposed between the second electrode and the second bus bar. The method for manufacturing a capacitor according to Claim 1 or 2.

4. A capacitor element having a first electrode, a second electrode provided on the opposite side of the first electrode, an elastic conductor member that entirely faces the first electrode and is elastically deformable in a direction connecting the first electrode and the second electrode, a first bus bar connected to the first electrode via the elastic conductor member, and a second bus bar connected to the second electrode; A sealing portion that seals the capacitor element. A capacitor.

5. The elastic conductor member is a first elastic conductor member. The capacitor element further has a second elastic conductor member that is elastically deformable in a direction connecting the first electrode and the second electrode. The second elastic conductor member is interposed between the second electrode and the second bus bar. The capacitor according to Claim 4.

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