Electrolytic capacitor

Abstract

To prevent adverse influences from being exerted upon a capacitor element by largely pressing and deforming a sealant inside of a main body case with a mold resin.SOLUTION: In an electrolytic capacitor, an external pressure deformation suppression plate is provided on a surface of a sealant on the side of an opening of a main body case. In the electrolytic capacitor, in an outer peripheral portion of the sealant on the surface on the side of the opening of the main body case, a plurality of holding parts is provided at predetermined intervals for holding an outer peripheral part of the external pressure deformation suppression plate. In the outer peripheral part of the external pressure deformation suppression plate, there are provided a plurality of held parts held by the holding parts of the sealant in an outer peripheral direction and a plurality of outer peripheral extension parts extending from the held parts in the outer peripheral direction. In a main body case portion of the sealant corresponding to a portion closer to the side of a capacitor element than the external pressure deformation suppression plate in a plate thickness direction, a restriction processing part in a radial direction of the sealant is provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] The electrolytic capacitor includes a cylindrical main case having one closed end and an opening at the other end, a capacitor element housed in the main case, and a plate-like sealing material sealing the opening of the main case. The capacitor element is formed by winding an anode foil and a cathode foil facing each other with a separator interposed therebetween, and one end of each of the anode foil and the cathode foil is connected to one end of a lead terminal. The other end of each of the lead terminals penetrates the sealing material and is extended to the outside of the opening of the main case.

[0003] In addition, it has been proposed to cover the outer surface of the main body case of the sealing material with an insulating inorganic layer in order to prevent thermal degradation of the sealing material (for example, Patent Document 1 below), to cover the outer surface of the main body case of the sealing material with a resin layer in order to prevent leakage of electrolyte from inside the main body case (for example, Patent Document 2 below), and to provide a ceramic reinforcing member on the outside of the main body case of the sealing material in order to prevent the sealing material from deforming outside the main body case due to an increase in air pressure inside the main body case (for example, Patent Document 3 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-140257 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-173241 [Patent Document 3] Japanese Patent Application Publication No. 08-293435 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in the above-mentioned prior art documents, the outer surface of the main body case of the sealing material is covered with an insulating inorganic layer (Patent Document 1), or with a resin layer (Patent Document 2), or a ceramic reinforcing member is provided on the outside of the main body case of the sealing material (Patent Document 3). However, the inorganic layer, resin layer, and ceramic reinforcing member have the same outer diameter as the sealing material, and are integrated with the sealing material by adhesion or the like.

[0006] However, if the inorganic layer, resin layer, and ceramic reinforcing member are integrated into the side of the opening of the encapsulant body case and the outer diameter of these components is the same as that of the encapsulant, the encapsulant will have difficulty following the expansion or contraction of the encapsulant body case due to the environment in which the electrolytic capacitor is placed, which will result in a decrease in the encapsulant's effectiveness in sealing the encapsulant body case.

[0007] Therefore, the present invention aims to prevent a decrease in the sealing effect of the main body case provided by the sealing material when the main body case expands or contracts due to the environment in which the electrolytic capacitor is placed, and to prevent the sealing material from being significantly pressed and deformed into the main body case by the molding resin when the outer periphery of the electrolytic capacitor is molded with the molding resin, which would have an adverse effect on the capacitor element. [Means for solving the problem]

[0008] To achieve this object, the present invention provides a cylindrical main case having one closed end and an opening at the other end, a capacitor element housed in the main case, and a plate-like sealing material sealing the opening, wherein the capacitor element is formed by winding an anode foil and a cathode foil facing each other with a separator interposed therebetween, and wherein one end of a first lead terminal is connected to the anode foil and one end of a second lead terminal is connected to the cathode foil, the other end of the first lead terminal passes through a first through-hole in the sealing material and is drawn out to the outside of the opening of the main case, and the other end of the second lead terminal passes through a second through-hole in the sealing material and is drawn out to the outside of the opening of the main case. In the electrolytic capacitor having the above-described structure, an external pressure deformation suppression plate is provided on the surface of the sealing material on the opening side of the main body case, and a plurality of holding portions are provided at a predetermined interval on the outer peripheral portion of the surface of the sealing material on the opening side of the main body case to hold the outer peripheral portion of the external pressure deformation suppression plate, and the outer peripheral portion of the external pressure deformation suppression plate is provided with a plurality of held portions that are held from the outer peripheral direction by the holding portions of the sealing material and a plurality of outer peripheral extension portions that extend in the outer peripheral direction beyond the held portions, and a portion of the main body case that corresponds to the portion of the sealing material that is closer to the capacitor element than the external pressure deformation suppression plate in the plate thickness direction is provided with a radially drawn portion of the sealing material.

[0009] In addition, in the electrolytic capacitor of the present invention, a bent portion is provided at the opening of the main body case, with the tip of the main body case on the opening side curved and bent toward the sealing material, and the tip of this bent portion abuts or is close to the surface of the external pressure deformation suppression plate on the opening side of the main body case, in a portion more inward than the holding portion of the sealing material.

[0010] Furthermore, the electrolytic capacitor of the present invention is configured such that a held portion is provided facing the outer periphery of the external pressure deformation suppression plate, and an outer periphery extension portion is provided on the outer periphery of the external pressure deformation suppression plate, perpendicular to the line connecting these opposed held portions.

[0011] In addition, the electrolytic capacitor of the present invention has holding portions arranged opposite each other on the outer peripheral portion of the surface of the sealing material on the opening side of the main body case, and the first through hole and the second through hole are arranged in the sealing material at a predetermined distance on a line connecting the opposing holding portions.

[0012] Furthermore, in the electrolytic capacitor of the present invention, the sealing material is circular, the external pressure deformation suppression plate is approximately elliptical, and a held portion is provided opposite the portion with a smaller diameter on the outer periphery of the approximately elliptical external pressure deformation suppression plate, and a peripheral extension portion is provided opposite the outer periphery of the approximately elliptical external pressure deformation suppression plate in a direction perpendicular to the line connecting these opposed held portions.

[0013] In addition, in the electrolytic capacitor of the present invention, the sealing material is circular and the external pressure deformation suppression plate is approximately circular. With the external pressure deformation suppression plate attached to the surface of the sealing material facing the opening of the main body case, the following are arranged in clockwise order: a first holding portion of the sealing material, a first peripheral extension of the external pressure deformation suppression plate, a second holding portion of the sealing material, a second peripheral extension of the external pressure deformation suppression plate, a third holding portion of the sealing material, a third peripheral extension of the external pressure deformation suppression plate, a fourth holding portion of the sealing material, a fourth peripheral extension of the external pressure deformation suppression plate, a fifth holding portion of the sealing material, a fifth peripheral extension of the external pressure deformation suppression plate, a sixth holding portion of the sealing material, and a sixth peripheral extension of the external pressure deformation suppression plate. The first holding portion of the sealing material, the first and second through holes, and the fourth holding portion are arranged in a straight line. The second and fifth peripheral extensions of the external pressure deformation suppression plate are arranged perpendicular to a line connecting the first holding portion and fourth holding portion of the sealing material.

[0014] Furthermore, the external pressure deformation suppression plate in the electrolytic capacitor of the present invention is made of a synthetic resin plate containing a reinforcing material. [Effects of the Invention]

[0015] As described above, the electrolytic capacitor of the present invention is configured such that an external pressure deformation suppression plate is provided on the surface of the sealing material facing the opening of the main body case, and a plurality of holding portions are provided at a predetermined interval on the outer periphery of the surface of the sealing material facing the opening of the main body case to hold the outer periphery of the external pressure deformation suppression plate.

[0016] In addition, the outer periphery of the external pressure deformation suppression plate is provided with a plurality of held portions that are held from the outer periphery by the holding portion of the sealing material, and a plurality of outer periphery extension portions that extend in the outer periphery direction beyond these held portions, and the main body case portion that corresponds to the portion of the sealing material that is closer to the capacitor element than the external pressure deformation suppression plate in the plate thickness direction is provided with a radially drawn portion of the sealing material.

[0017] Therefore, in the present invention, the sealing effect of the main body case provided by the sealing material is prevented from decreasing when the main body case expands or contracts due to the environment in which the electrolytic capacitor is placed, and when the outer periphery of the electrolytic capacitor is molded with molding resin, the molding resin can be prevented from significantly pressing and deforming the sealing material into the main body case, which would have an adverse effect on the capacitor element.

[0018] That is, in the present invention, an external pressure deformation suppression plate is provided on the surface of the sealing material facing the opening of the main body case, and multiple holding portions that hold the outer periphery of the external pressure deformation suppression plate are provided at predetermined intervals on the outer periphery of the surface of the sealing material facing the opening of the main body case.Therefore, the outer periphery of the sealing material is less likely to be restricted by the external pressure deformation suppression plate, and when the main body case expands or contracts due to the environment in which the electrolytic capacitor is placed, the outer periphery of the sealing material responds by expanding and contracting, and as a result, the sealing effect of the main body case can be prevented from decreasing.

[0019] Furthermore, when the outer periphery of the electrolytic capacitor is molded with molding resin, part of the molding resin flows into the main case through the opening of the main case, pushing the sealing material toward the capacitor element. However, in the present invention, an external pressure deformation suppression plate is provided on the sealing material side of the main case opening, so the sealing material does not deform significantly toward the capacitor, and as a result, adverse effects on the capacitor element can be prevented.

[0020] That is, in the present invention, the outer periphery of the external pressure deformation suppression plate is provided with a plurality of held portions that are held from the outer periphery by the holding portion of the sealing material, and a plurality of outer periphery extension portions that extend in the outer periphery direction beyond these held portions, and the main body case portion that corresponds to the portion of the sealing material that is closer to the capacitor element than the external pressure deformation suppression plate in the plate thickness direction is provided with a radially drawn portion of the sealing material.

[0021] Therefore, even if part of the molded resin flows into the main body case through the opening in the main body case, the outer peripheral extension of the external pressure deformation suppression plate is pressed against the narrowed portion of the main body case via the sealing material, and as a result, the sealing material does not deform significantly toward the capacitor, thereby preventing any adverse effects on the capacitor element. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view showing a state in which an electrolytic capacitor according to a first embodiment of the present invention is mounted on a substrate. [Figure 2] FIG. 1 is a cross-sectional view showing a cross section of an electrolytic capacitor according to a first embodiment. [Figure 3] FIG. 1 is an enlarged cross-sectional view showing a main part of an electrolytic capacitor according to a first embodiment. [Figure 4] FIG. 1 is a plan view showing a sealing material of an electrolytic capacitor according to a first embodiment; [Figure 5] FIG. 1 is an exploded perspective view showing a sealing material of an electrolytic capacitor according to a first embodiment; [Figure 6] FIG. 1 is a cross-sectional view showing the electrolytic capacitor according to the first embodiment molded with molding resin; [Figure 7] FIG. 10 is a plan view showing a sealing material of an electrolytic capacitor according to a second embodiment of the present invention; [Figure 8] FIG. 10 is an exploded perspective view showing a sealing material of an electrolytic capacitor according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a plan view showing a sealing material of an electrolytic capacitor according to a third embodiment of the present invention. [Figure 10]FIG. 10 is an exploded perspective view showing a sealing material of an electrolytic capacitor according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] (Embodiment 1) Fig. 1 is a cross-sectional view showing an electrolytic capacitor according to a first embodiment of the present invention mounted on a substrate, and Fig. 2 is an enlarged cross-sectional view showing a main part of the electrolytic capacitor according to the first embodiment.

[0024] As shown in Figures 1 and 2, the electrolytic capacitor 1 comprises a cylindrical main body case 4 that is closed at one end and has an opening 3 at the other end, a capacitor element 5 housed within the main body case 4, and a plate-like sealing material 6 that seals the opening 3 of the main body case 4.

[0025] The main body case 4 is made of aluminum, for example, and the sealing material 6 is made of butyl rubber, for example.

[0026] As is known from the above-mentioned prior art documents, capacitor element 5 is configured by winding an anode foil (not shown) and a cathode foil (not shown) facing each other with a separator (not shown) in between.

[0027] In addition, one end of a lead terminal 7a is connected to the anode foil of the capacitor element 5, and the other end of the lead terminal 7a passes through the through hole 6a of the sealing material 6 and is pulled out to the outside of the opening 3 of the main body case 4.

[0028] Furthermore, one end of lead terminal 7b is connected to the cathode foil of capacitor element 5, and the other end of lead terminal 7b passes through through-hole 6b of sealing material 6 and is drawn out to the outside of opening 3 of main body case 4. Furthermore, capacitor element 5 holds an electrolyte.

[0029] In addition, the electrolytic capacitor 1 shown in Figure 1 is provided with a well-known base plate 1a to improve mountability on the circuit board 2, and the tips on the other ends of the lead terminals 7a and 7b pass through the base plate 1a and are bent to the left and right, and these bent parts serve as the parts to be soldered to the circuit board 2.

[0030] A characteristic feature of this embodiment is that, as shown in Figures 1 and 2, a plate-shaped external pressure deformation suppression plate 8 is provided on the surface of the sealing material 6 on the side of the opening 3 of the main body case 4 (see also Figures 4 and 5 described below).

[0031] The sealing material 6 and the external pressure deformation suppression plate 8 will be described.

[0032] The sealing material 6 of this embodiment is an insulating elastic material such as butyl rubber or ethylene propylene rubber, and is in the form of a circular plate.

[0033] The external pressure deformation suppression plate 8 is made of a synthetic resin plate mixed with a reinforcing material (glass fiber, cellulose fiber, ceramic, etc.), and one example is Bakelite (registered trademark).

[0034] The thickness of the external pressure deformation suppression plate 8 is thinner than the thickness of the sealing material 6 .

[0035] Fig. 4 is a plan view showing the sealing material for the electrolytic capacitor according to the first embodiment. Fig. 5 is an exploded perspective view showing the sealing material for the electrolytic capacitor according to the first embodiment. As shown in Figs. 4 and 5, the external pressure deformation suppression plate 8 has a generally elliptical shape. In this generally elliptical external pressure deformation suppression plate 8, held portions 8a are provided facing each other on both side portions (outer peripheral portions) in the direction of the smaller diameter, and outer peripheral extension portions 8b are provided facing each other on both sides of the outer peripheral portion of the generally elliptical external pressure deformation suppression plate 8 in a direction perpendicular to the line connecting these facing held portions 8a.

[0036] On the other hand, on the outer peripheral portion of the surface of the sealing material 6 on the side of the opening 3 of the main body case 4, holding portions 6c and 6d are provided at a predetermined interval to hold the held portion 8a arranged on the outer peripheral portion of the external pressure deformation suppression plate 8.

[0037] The retaining portions 6c and 6d arranged on the outer periphery of the surface of the sealing material 6 facing the opening 3 of the main case 4 (see FIG. 1) are arranged on both sides of the straight line connecting the through holes 6a and 6b, as shown in FIGS. 4 and 5, and protrude from the surface of the sealing material 6 facing the opening 3 of the main case 4 toward the opening 3 of the main case 4. In other words, the retaining portions 6c and 6d are arranged facing each other on the outer periphery of the surface of the sealing material 6 facing the opening 3 of the main case 4, and the through holes 6a and 6b are arranged at a predetermined distance apart on the line connecting the opposing retaining portions 6c and 6d in this sealing material 6.

[0038] The inner peripheral shape of the holding portions 6c and 6d is concave so as to fit and hold the outer peripheral shape (convex) of the external pressure deformation suppression plate 8.

[0039] On the other hand, as described above, the approximately elliptical external pressure deformation suppression plate 8 has the held portions 8a arranged opposite to each other on the outer periphery in the direction of the smaller diameter, and the outer periphery of the approximately elliptical external pressure deformation suppression plate 8 has the outer periphery extension portions 8b arranged opposite to each other on the outer periphery in the direction perpendicular to the line connecting these opposed held portions 8a.

[0040] 4, with this configuration, one held portion 8a of the external pressure deformation suppression plate 8 is held by the holding portion 6c of the sealing material 6, and the other held portion 8a of the external pressure deformation suppression plate 8 is held by the holding portion 6d of the sealing material 6. The holding of one held portion 8a of the external pressure deformation suppression plate 8 by the holding portion 6c of the sealing material 6 and the holding of the other held portion 8a of the external pressure deformation suppression plate 8 by the holding portion 6d of the sealing material 6 are achieved by the elasticity and friction between the rubber elasticity that constitutes the sealing material 6 and the plate-like end face that constitutes the external pressure deformation suppression plate 8.

[0041] As shown in Figure 4, between the left and right held portions 8a of the external pressure deformation suppression plate 8, in the portions corresponding to the through holes 6a and 6b of the sealing material 6, through holes 8c and 8d are provided, through which the other ends of the lead terminals 7a and 7b pass.

[0042] Next, as shown in Figure 2, a portion of the main body case 4 that corresponds to the portion of the sealing material 6 closer to the capacitor element 5 in the thickness direction than the external pressure deformation suppression plate 8 is provided with a radially drawn portion 4a of the sealing material 6.

[0043] 2, the opening 3 of the main body case 4 is provided with a bent portion 4b, which is formed by bending the tip of the opening side of the main body case 4 toward the sealing material 6, and the tip of this bent portion 4b abuts against or is close to the surface of the external pressure deformation suppression plate 8 on the opening 3 side of the main body case 4, in a portion that is more inward than the holding portions 6c and 6d of the sealing material 6. The tip of the bent portion 4b does not bite into the external pressure deformation suppression plate 8.

[0044] Fig. 6 is a cross-sectional view showing the electrolytic capacitor according to the first embodiment molded with mold resin. In the electrolytic capacitor 1 of this embodiment configured as described above, the main body casing 4 can be molded together with the circuit board 2 in mold resin 9, as shown in Fig. 6, for the purpose of improving waterproofing, moisture resistance, chemical resistance, and dust resistance, for example. In this molding, the electrolytic capacitor 1 side (front side) of the electrolytic capacitor 1 and the circuit board 2 may be molded with mold resin 9, or the back side of the circuit board 2 may also be molded together.

[0045] As is well known, molding is performed by placing the circuit board 2 on which the electrolytic capacitor 1 is mounted in a mold (not shown) and injecting molding resin 9 under pressure from a resin injection port (not shown) of the mold.

[0046] Although the molded resin 9 is in this pressurized injection state, in this embodiment, an external pressure deformation suppression plate 8 is provided on the opening 3 side of the sealing material 6 in the main case 4, so that the pressure force of the molded resin 9 is received by the external pressure deformation suppression plate 8, and as a result, the sealing material 6 does not deform significantly toward the capacitor element 5, thereby preventing any adverse effects on the capacitor element 5.

[0047] The features of this embodiment will be further described below.

[0048] As described above, the external pressure deformation suppression plate 8 of this embodiment has a roughly elliptical shape, with held portions 8a provided opposite each other on both sides of the outer peripheral surface in the direction of the smaller diameter, and outer peripheral extension portions 8b provided opposite each other on both sides of the outer peripheral portion of the roughly elliptical external pressure deformation suppression plate 8 in a direction perpendicular to the line connecting these opposed held portions 8a.

[0049] In other words, the outer peripheral extension 8b extends outward (toward the inner surface of the main body case 4) more than the held portion 8a.

[0050] On the other hand, on the outer peripheral portion of the surface of the sealing material 6 on the side of the opening 3 of the main body case 4, holding portions 6c and 6d are provided at a predetermined interval to hold the held portion 8a arranged on the outer peripheral portion of the external pressure deformation suppression plate 8.

[0051] The retaining portions 6c and 6d arranged on the outer peripheral portion of the surface of the sealing material 6 facing the opening 3 of the main case 4 are arranged on both sides of the straight line connecting the through holes 6a and 6b, as shown in Figure 5, and protrude from the surface of the sealing material 6 facing the opening 3 of the main case 4 toward the opening 3 of the main case 4.

[0052] In other words, the holding portions 6c and 6d are arranged opposite each other on the outer peripheral portion of the surface of the sealing material 6 on the side of the opening 3 of the main body case 4, and in this sealing material 6, the through holes 6a and 6b are arranged at a predetermined distance apart on the line connecting the oppositely arranged holding portions 6c and 6d.

[0053] The inner peripheral shape of the holding portions 6c, 6d is concave to match the outer peripheral shape (convex) of the external pressure deformation suppressing plate 8 and to hold the held portion 8a of this external pressure deformation suppressing plate 8.

[0054] With this configuration, as shown in Figure 4, one of the held portions 8a of the external pressure deformation suppression plate 8 is held by the holding portion 6c of the sealing material 6, and the other held portion 8a of the external pressure deformation suppression plate 8 is held by the holding portion 6d of the sealing material 6.

[0055] In this state, the outer peripheral extensions 8 b on both sides of the outer periphery of the external pressure deformation suppression plate 8 are in close proximity to the inner surface of the main body case 4 .

[0056] As shown in Figure 2, the portion of the main body case 4 that corresponds to the portion of the sealing material 6 closer to the capacitor element 5 than the external pressure deformation suppression plate 8 in the thickness direction has a drawn portion 4a formed in the radial direction of the sealing material 6, as described above.

[0057] Continuing the explanation using Figure 2, Figure 2 shows the portion where the held portions 8a provided on both sides of the external pressure deformation suppression plate 8 in the direction of the smaller diameter dimension are held by the holding portions 6c and 6d of the sealing material 6.

[0058] As can be seen from FIG. 2, the outer diameter of the external pressure deformation suppression plate 8 at the portion held by the holding portions 6c and 6d of the sealing material 6 is smaller than the diameter of the inner surface of the drawn portion 4a of the main case 4.

[0059] In contrast, the outer diameter of the outer peripheral extension 8b of the external pressure deformation suppression plate 8 is larger outward than the outer diameter of the portion of the sealing material 6 held by the holding portions 6c and 6d.

[0060] In other words, in Figure 1, the outer diameter of the outer peripheral extension portion 8b of the external pressure deformation suppression plate 8 is the same as or larger than the diameter of the inner surface of the drawn portion 4a of the main body case 4, and is closer to the inner surface of the main body case 4 than the held portion 8a of the external pressure deformation suppression plate 8.

[0061] As a result, when the external pressure deformation suppression plate 8 is subjected to the pressure force of the molded resin 9, the inner surface of the drawn portion 4a of the main body case 4 can be made to support the external pressure deformation suppression plate 8 being pushed inward into the main body case 4 at the outer peripheral extension portion 8b of the external pressure deformation suppression plate 8.

[0062] As a result, the sealing material 6 does not deform significantly toward the capacitor element 5, and this makes it possible to prevent adverse effects on the capacitor element 5.

[0063] In addition, the outer peripheral extensions 8b of the external pressure deformation suppression plate 8 are provided on both sides of the outer periphery of the approximately elliptical external pressure deformation suppression plate 8 in a direction perpendicular to the line connecting the opposing held portions 8a on both sides of the outer periphery.

[0064] For this reason, as described above, the outer diameter of the retained portion 8a of the external pressure deformation suppression plate 8 is smaller than that of the outer peripheral extension portion 8b, and as a result, when the external pressure deformation suppression plate 8 is subjected to the pressure force of the molded resin 9, there is a risk that it will be pushed into the main body case 4.

[0065] However, as can be seen from FIG. 1, in this embodiment, the held portions 8a of the external pressure deformation suppression plate 8 are arranged on both sides of the straight line connecting the through holes 6a and 6b of the sealing material 6.

[0066] Therefore, when the held portion 8a of the external pressure deformation suppression plate 8 is pushed into the main body case 4, the capacitor element 5 supports it via the lead terminals 7a, 7b on both sides.

[0067] Of course, in this case, a load will be applied to the capacitor element 5, but as described above, the outer peripheral extension 8b of the external pressure deformation suppression plate 8 is supported by the inner surface of the drawn portion 4a of the main body case 4 via the sealing material 6, so the held portion 8a of the external pressure deformation suppression plate 8 will not be pushed significantly inward into the main body case 4.

[0068] As a result, the sealing material 6 does not deform significantly toward the capacitor element 5, and this makes it possible to prevent adverse effects on the capacitor element 5.

[0069] This is a revolutionary effect in molding electrolytic capacitor 1 with molding resin 9, and in the future it will be easy to mold electrolytic capacitor 1 with molding resin 9 to improve its waterproofing, moisture resistance, chemical resistance, and dust resistance.

[0070] As described above, in the product of this embodiment, the main body case 4 can be molded together with the circuit board 2 with the molding resin 9.

[0071] Even when not molded with the molding resin 9, the product of this embodiment exhibits excellent effects.

[0072] In other words, when expansion or contraction of the main case 4 occurs in the environment in which the electrolytic capacitor 1 is placed, the sealing material 6 deforms into a convex shape toward the opening 3 of the main case 4 or a concave shape toward the inside of the main case 4, thereby preventing a decrease in the sealing effect of the sealing material 6 on the main case 4. However, if an external pressure deformation suppression plate 8 is attached to the sealing material 6, the expansion and contraction of the sealing material 6 is restricted by the external pressure deformation suppression plate 8, preventing effective expansion and contraction, which may result in a decrease in the sealing effect of the sealing material 6 on the main case 4.

[0073] In contrast to this, in the present embodiment, one of the held portions 8a of the external pressure deformation suppression plate 8 is held by the holding portion 6c of the sealing material 6, and the other of the held portions 8a of the external pressure deformation suppression plate 8 is held by the holding portion 6d of the sealing material 6. Therefore, when the main body case 4 expands or contracts due to the environment in which the electrolytic capacitor 1 is placed, the sealing material 6 responds by deforming, and as a result, the sealing effect of the main body case 4 can be prevented from decreasing.

[0074] (Embodiment 2) 7 and 8 are diagrams showing an electrolytic capacitor according to a second embodiment of the present invention.

[0075] As shown in Figures 7 and 8, in this embodiment, notches are provided in the held portion 8a of the circular external pressure deformation suppression plate 8A, into which the holding portions 6c and 6d of the sealing material 6 fit, and these notches form the held portion 8a.

[0076] Furthermore, the outer peripheral extension 8b of the circular external pressure deformation suppression plate 8A extends outward from the held portion 8a formed by the cutout, and therefore the outer peripheral extension 8b extends outward from the held portion 8a.

[0077] The effects of this embodiment are the same as those of the first embodiment.

[0078] (Embodiment 3) 9 and 10 are diagrams showing an electrolytic capacitor according to a third embodiment of the present invention.

[0079] As shown in Figures 9 and 10, in this embodiment, the sealing material 6A is circular, and the external pressure deformation suppression plate 8B is approximately circular, and the external pressure deformation suppression plate 8B is attached to the surface of the sealing material 6A facing the opening 3 of the main body case 4.

[0080] When the external pressure deformation suppression plate 8B is attached to the surface of the sealing material 6A facing the opening 3 of the main body case 4, the following are arranged in a clockwise direction: the retaining portion 6e of the sealing material 6A, the peripheral extension 8e of the external pressure deformation suppression plate 8B, the retaining portion 6f of the sealing material 6A (first retaining portion in the claims), the peripheral extension 8f of the external pressure deformation suppression plate 8B (first peripheral extension in the claims), the retaining portion 6g of the sealing material 6A, the peripheral extension 8g of the external pressure deformation suppression plate 8B, the retaining portion 6h of the sealing material 6A, the peripheral extension 8h of the external pressure deformation suppression plate 8B, the retaining portion 6i of the sealing material 6A, the peripheral extension 8i of the external pressure deformation suppression plate 8B, the retaining portion 6j of the sealing material 6A, and the peripheral extension 8j of the external pressure deformation suppression plate 8B.

[0081] The holding portions 6e, 6f, 6g, 6h, 6i, and 6j of the sealing material 6A are formed by protruding from the outer periphery of the surface of the circular sealing material 6A on the opening 3 side of the main body case 4 toward the opening 3, and a predetermined distance is provided between each of the holding portions 6e to 6j.

[0082] Additionally, outer peripheral extensions 8e, 8f, 8g, 8h, 8i, and 8j are arranged at predetermined intervals on the outer periphery of the external pressure deformation suppression plate 8B.

[0083] These outer peripheral extensions 8e, 8f, 8g, 8h, 8i, and 8j are formed by cutting out adjacent outer peripheral extensions 8e-8j in the external pressure deformation suppression plate 8B.

[0084] Furthermore, the holding portions 6e to 6j of the sealing material 6A are fitted into the cutout portions (these are the held portions) between the adjacent outer peripheral extension portions 8e to 8j.

[0085] That is, the portions of the outer periphery of the external pressure deformation suppression plate 8B that face the inner surfaces of the holding portions 6e to 6j of the sealing material 6A are the held portions.

[0086] Furthermore, in the external pressure deformation suppression plate 8B, the peripheral extensions 8e to 8j are extended outward beyond the cutouts (held portions) that are provided to fit into the holding portions 6e to 6j of the sealing material 6A, and therefore can function as the peripheral extensions 8e to 8j.

[0087] Furthermore, the retaining portion 6i of the sealing material 6A, the through holes 6a, 6b, and the retaining portion 6f are arranged in a straight line, and the outer peripheral extension portion 8j and the outer peripheral extension portion 8g of the external pressure deformation suppression plate 8B are arranged in a portion perpendicular to the line connecting the retaining portion 6i and the retaining portion 6f of the sealing material 6A.

[0088] The effects of this embodiment are the same as those of the first embodiment. [Explanation of symbols]

[0089] 1 electrolytic capacitor 1a Seat board 2 Circuit Boards 3 Opening 4 Main unit case 4a Drawing section 4b Bend part 5 Capacitor elements 6. Encapsulating material 6A Encapsulant 6a Through hole 6b Through hole 6c Holding part 6d holding part 6e Holding part 6f Holding part 6g holding part 6h Holding part 6i Holding part 6j Holding part 7a Lead terminal 7b Lead terminal 8. External pressure deformation suppression plate 8A External pressure deformation suppression plate 8B External pressure deformation suppression plate 8a Holding part 8b Perimeter extension 8c through hole 8d through hole 8e Peripheral extension 8f outer circumference extension 8g outer circumference extension 8h External extension 8i Perimeter extension 8j External extension 9 Molding resin

Claims

1. The capacitor comprises a cylindrical main body case having one closed end and an opening at the other end, a capacitor element housed in the main body case, and a plate-like sealing material sealing the opening, In the electrolytic capacitor, the capacitor element is formed by winding an anode foil and a cathode foil facing each other with a separator interposed therebetween, one end of a first lead terminal is connected to the anode foil, one end of a second lead terminal is connected to the cathode foil, the other end of the first lead terminal passes through a first through-hole in the sealing material and is drawn out to the opening of the main body case, and the other end of the second lead terminal passes through a second through-hole in the sealing material and is drawn out to the opening of the main body case, an external pressure deformation suppression plate is provided on a surface of the sealing material on the side of the opening of the main body case; a plurality of holding portions are provided at predetermined intervals on the outer periphery of the sealing material on the surface on the opening side of the main body case, the holding portions holding the outer periphery of the external pressure deformation suppression plate; a plurality of held portions that are held from the outer circumferential direction by the holding portion of the sealing material, and a plurality of outer circumferential extension portions that extend in the outer circumferential direction beyond the held portions, on the outer circumferential portion of the external pressure deformation suppression plate; An electrolytic capacitor in which a portion of the body case corresponding to a portion of the sealing material closer to the capacitor element than the external pressure deformation suppression plate in the plate thickness direction is provided with a drawn portion in the radial direction of the sealing material.

2. 2. The electrolytic capacitor of claim 1, wherein the opening of the main body case has a bent portion formed by bending the tip of the opening side of the main body case toward the sealing material, and the tip of this bent portion abuts or is close to the surface of the external pressure deformation suppression plate on the opening side of the main body case, in a portion that is more inward than the holding portion of the sealing material.

3. a supported portion is provided on an outer periphery of the external pressure deformation suppression plate in an opposing relationship; 3. The electrolytic capacitor according to claim 2, wherein an outer peripheral extension is provided on the outer peripheral portion of the external pressure deformation suppression plate, the outer peripheral portion being perpendicular to a line connecting the opposed held portions.

4. 4. The electrolytic capacitor of claim 3, wherein a holding portion is arranged facing the outer periphery of the surface of the sealing material on the opening side of the main body case, and the first through hole and the second through hole are arranged at a predetermined distance apart in the sealing material on a line connecting the opposing holding portions.

5. The sealing material has a circular shape, The external pressure deformation suppression plate has a substantially elliptical shape, a held portion is provided in a facing relationship to a portion of the outer periphery of the substantially elliptical external pressure deformation suppression plate that has a small diameter; 5. The electrolytic capacitor according to claim 4, wherein an outer peripheral extension is provided on the outer periphery of the substantially elliptical external pressure deformation suppressing plate in a direction perpendicular to the line connecting the opposed held portions.

6. The sealing material has a circular shape, The external pressure deformation suppression plate has a substantially circular shape, With an external pressure deformation suppression plate attached to the surface of the sealing material on the opening side of the main body case, Arranged in a clockwise direction are a first holding portion of the sealing material, a first outer peripheral extension of the external pressure deformation suppression plate, a second holding portion of the sealing material, a second outer peripheral extension of the external pressure deformation suppression plate, a third holding portion of the sealing material, a third outer peripheral extension of the external pressure deformation suppression plate, a fourth holding portion of the sealing material, a fourth outer peripheral extension of the external pressure deformation suppression plate, a fifth holding portion of the sealing material, a fifth outer peripheral extension of the external pressure deformation suppression plate, a sixth holding portion of the sealing material, and a sixth outer peripheral extension of the external pressure deformation suppression plate; the first holding portion, the first through hole, the second through hole, and the fourth holding portion are arranged in a linear manner; 5. The electrolytic capacitor according to claim 4, wherein the second and fifth peripheral extensions of the external pressure deformation suppression plate are arranged at portions perpendicular to a line connecting the first and fourth holding portions of the sealing material.

7. 7. The electrolytic capacitor according to claim 1, wherein the external pressure deformation suppression plate is made of a synthetic resin plate containing a reinforcing material.

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