JP5330137B2 - Electrolytic capacitors, circuit boards and electronic equipment - Google Patents

Description

    The present invention relates to an electrolytic capacitor, a circuit board, and an electronic device.

  In the electrolytic capacitor, a capacitor element containing an electrolytic solution is housed in a metal case. And when a voltage higher than a rating is applied to the electrolytic capacitor, the internal pressure of the metal case increases due to generation of gas (hydrogen gas) or evaporation of the electrolytic solution. When the internal pressure suddenly increases, the electrolytic capacitor may explode. To prevent this, the electrolytic capacitor is provided with a safety valve that opens when the internal pressure exceeds a predetermined threshold.

  On the other hand, the vaporized electrolyte etc. released to the outside of the electrolytic capacitor due to the increase in internal pressure tend to be accompanied by white smoke and off-flavor, so when the electrolyte etc. vaporized from the safety valve is released, the electrolytic capacitor is provided. Gives anxiety to users who use electronic devices. In addition to this, when the safety valve is opened, there is a problem that the electrolyte discharged to the outside of the electrolytic capacitor adheres to the substrate and other electronic components. In order to solve such problems, the gas released by opening the safety valve, vaporized electrolyte, etc. are sealed in a sealing member such as a cap attached to the outside of the electrolytic capacitor to surround the electrolytic capacitor. Have been proposed (see Patent Documents 1 and 2).

JP-A-2006-286969 (Claims 1, 2 etc.) JP 2005-44868 (Claim 1 etc.)

  However, in the electrolytic capacitors disclosed in Patent Documents 1 and 2, the strength of the sealing portion between the sealing member and the electrolytic capacitor main body is insufficient. For this reason, when the pressure by the vaporized electrolyte or the like released from the safety valve and sealed in the sealing member becomes high, the seal portion is broken or, in the worst case, the sealing member is Vaporized electrolyte or the like may leak to the outside due to being blown off from the electrolytic capacitor body.

  The present invention has been made in view of the above problems, and even when the pressure of a gas made of vaporized electrolyte or the like discharged from a safety valve and sealed in a sealing member becomes high, the gas is not It is an object of the present invention to provide an electrolytic capacitor capable of reliably suppressing leakage to the outside, and a circuit board and an electronic device using the same.

The above-mentioned subject is achieved by the following present invention. That is,
The electrolytic capacitor of the present invention includes an electrolytic capacitor element, a cylindrical case that accommodates the electrolytic capacitor element therein, an annular recess provided on the outer peripheral surface of the cylindrical case along the circumferential direction, and an outer surface of the cylindrical case An electrolytic capacitor having a safety valve provided at a position that does not overlap with the annular recess, and having at least one opening and shutting off at least the safety valve provided on the outer surface of the cylindrical case and its surroundings from the external atmosphere An inflatable sealing member that is fixed to the outer surface of the cylindrical case with the opening side in close contact with the annular recess, and is disposed along the annular recess. the opening side, in the circumferential direction of the cylindrical case so as to sandwich between the annular recess, e Bei and a coil spring which is wound as the number of turns exceeds one, of the sealing member, Koiruba The thickness of the portion on the opening side is thicker than the vicinity of the portion that is in close contact with and fixed to the annular recess, and the coil spring of the sealing member causes the annular recess to The thickness of the part on the opposite side to the said opening part is thinner with respect to the said part vicinity than the thickness of the part vicinity fixed closely .

  In one embodiment of the electrolytic capacitor of the present invention, the number of turns of the coil spring is preferably 2 to 5 times.

  In another embodiment of the electrolytic capacitor of the present invention, it is preferable that at least the end portion closer to the safety valve side among the both end portions of the coil wire constituting the coil spring is disposed at a position separated from the outer surface of the sealing member. .

  In another embodiment of the electrolytic capacitor of the present invention, it is preferable that the entire inner surface of the sealing member is in close contact with the outer surface of the cylindrical case.

  The circuit board of the present invention includes the electrolytic capacitor of the present invention.

  An electronic apparatus according to the present invention includes the electrolytic capacitor according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, even if the pressure by the gas which consists of vaporized electrolyte solution etc. which were discharge | released from the safety valve and was enclosed in the sealing member becomes high pressure, it can suppress reliably that gas leaks outside. An electrolytic capacitor, and a circuit board and an electronic device using the same can be provided.

It is an external view which shows an example of the electrolytic capacitor of this embodiment. It is sectional drawing of the electrolytic capacitor of this embodiment shown in FIG. It is sectional drawing of the sealing member before attaching to the electrolytic capacitor main body shown in FIG. It is a top view of the coil spring shown in FIG. 1 and FIG. It is a schematic diagram which shows an example of the positional relationship of the both ends of the coil spring in the diameter direction of the electrolytic capacitor of this embodiment, and the outer surface in the opening-part vicinity part of a sealing member. It is a schematic diagram which shows the other example of the coil spring used for the electrolytic capacitor of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are views showing an example of the electrolytic capacitor of the present embodiment. FIG. 1 is an external view when the electrolytic capacitor is viewed from the side. FIG. 2 is a cross-sectional view of the electrolytic capacitor shown in FIG. is there. The electrolytic capacitor 10 is mainly composed of an electrolytic capacitor body 20, a sealing member 40 that seals a gas made of vaporized electrolyte or the like (hereinafter sometimes simply referred to as “gas”), and a coil spring 60. Composed.

  The electrolytic capacitor body 20 includes an electrolytic capacitor element 22, a cylindrical case 24 with a bottom that houses the electrolytic capacitor element 22, and an outer peripheral surface 24 </ b> A on the side surface of the cylindrical case 24 along the circumferential direction. An annular recess 26 provided on the bottom, a safety valve 28 provided on the outer surface on the bottom side of the cylindrical case 24, and a sealing member 30 that seals the electrolytic capacitor element 22 in the cylindrical case 24. In the example shown in FIGS. 1 and 2, the safety valve 28 is provided on the end surface 24 </ b> B side which is the bottom surface side of the cylindrical case 24. It may be provided. Further, an opening 24C is provided on the side facing the end surface 24B of the cylindrical case 24. Here, the electrolytic capacitor element 22 is accommodated in a sealed state in the cylindrical case 24 by a sealing member 30 disposed on the opening 24C side of the cylindrical case 24A.

  The electrolytic capacitor element 22 is configured by winding a laminated sheet in which an anode foil, electrolytic paper, and a cathode foil are laminated in this order. Here, the anode foil has an aluminum oxide film functioning as a dielectric on the surface of the roughened aluminum foil. The cathode foil is made of an aluminum foil. The electrolytic paper is a paper base material impregnated with an electrolytic solution using an organic solvent, and prevents the anode foil and the cathode foil from contacting each other. Also, two lead terminals 32A and 32B are electrically connected to the electrolytic capacitor element 22, one lead terminal 32A is connected to the anode foil, and the other lead terminal 32B is connected to the cathode foil. Yes. These two lead terminals 32 </ b> A and 32 </ b> B penetrate the sealing member 30 and are exposed to the outside of the electrolytic capacitor body 20.

  The safety valve 28 provided on the outer surface of the cylindrical case 24 moves out of the cylindrical case 24 when the gas pressure of the gas generated in the cylindrical case 24 exceeds a certain threshold value when the electrolytic capacitor 10 fails. If it has a structure which can discharge | release gas, it will not specifically limit. Normally, the safety valve 28 is formed in the end surface 24B of the cylindrical case 24 in a groove shape thinner than the surroundings as shown in FIG. Thereby, when the internal pressure in the cylindrical case 24 increases, the safety valve 28 is ruptured, thereby releasing gas to the outside of the cylindrical case 24 and preventing the electrolytic capacitor body 20 from rupturing.

  The sealing member 40 is made of a material that can be easily stretched and deformed so that it can expand. The sealing member 40 has one opening 42 as shown in FIGS. 2 and 3, and is a cylinder so as to block at least the safety valve 28 provided on the outer surface of the cylindrical case 24 and its surroundings from the outside atmosphere. The cylindrical case 24 is covered and fixed to the outer surface of the cylindrical case 24 with the opening 42 side in close contact with the annular recess 26. FIG. 3 shows a cross-sectional view of the sealing member 40 before being attached to the electrolytic capacitor body 20 shown in FIG. In the example shown in FIGS. 1 and 2, the sealing member 40 covers the end face 24 </ b> B and the outer peripheral face 24 </ b> A of the cylindrical case 24 in a substantially intimate contact state. For this reason, when the gas in which the electrolyte is vaporized at the time of failure is released from the safety valve 28, the sealing member 40 expands so that the gas does not leak to the outside between the electrolytic capacitor body 22 and the sealing member 40. Can be contained.

  The material constituting the sealing member 40 is a material that can be easily stretched and deformed when a tension is applied from the inner surface 46 side of the sealing member 40 by releasing gas from the safety valve 28. For example, rubber materials such as silicone rubber and natural rubber, and resin materials such as vinyl resin can be used. Of these two types of materials, a rubber material in which the sealing member 40 that has once expanded at the time of failure returns to its original state as time passes is more preferable. In addition, on the outer surface of the cylindrical case 24, various types of information regarding the electrolytic capacitor 10 such as the manufacturer, model number, and capacitance of the electrolytic capacitor 10 are usually printed. For this reason, in order that the electrolytic capacitor main body 20 is easily covered with the sealing member 40 to facilitate confirmation of the information, the material constituting the sealing member 40 is preferably transparent or translucent. It is. In view of the stretch deformability and internal visibility described above, silicone rubber is particularly suitable as the material constituting the sealing member 40. Moreover, since it is estimated that the temperature of the vaporized electrolyte solution reaches about 150 ° C. to 200 ° C., silicone rubber is preferable from the viewpoint of heat resistance against such high temperatures.

  The coil spring 60 is disposed along the annular recess 26 and is wound in the circumferential direction of the cylindrical case 24 so as to sandwich the side close to the opening 42 of the sealing member 40 with the annular recess 26. Is wound more than once. Therefore, a uniform pressing force is applied to the sealing member 40 without any gap in the entire circumferential direction of the annular recess 26 by the coil spring 60. For this reason, the sealing member 40 is firmly and firmly fixed to the entire circumferential direction of the annular recess 26 without any gap. Therefore, even if the gas pressure of the gas released from the safety valve 28 and confined by the sealing member 40 is significantly increased to a high pressure and the sealing member 40 swells greatly, the sealing member 40 is detached. Without leaking, the gas can be prevented from leaking outside. Further, since the coil spring is disposed along the annular recess 26, the coil spring 60 can be prevented from being caught in the annular recess 26 and sliding in the axial direction of the electrolytic capacitor body 20. Further, the annular recess 26 is a drawing portion that is usually provided by drawing the cylindrical case 24 when the electrolytic capacitor body 20 is assembled to seal the contents. For this reason, it is not necessary to newly provide a protrusion or a recess on the outer peripheral surface of the cylindrical case 24 so that the coil spring 60 does not slide in the axial direction of the electrolytic capacitor body 20.

  In addition to the method of using the coil spring 60, the method of fixing the sealing member 40 in close contact with the annular recess 26 includes, for example, (1) a method using an O-ring, and (2) an outer peripheral length of the annular recess 26. A method of winding both ends of the wire after winding a slightly longer wire is also considered an effective method. However, none of the methods shown in (1) and (2) is practical and unusable.

  The reason is as follows. First, in the method shown in (1) above, O-ring deterioration with time occurs. For this reason, after a long time when there is a high possibility that a failure will occur, the O-ring loses the function of closely sealing and fixing the sealing member 40 to the annular recess 26, or the function is greatly deteriorated. become. Further, when the gas pressure rises to a high pressure, the gas leakage cannot be completely prevented by the tightening force of the O-ring. Therefore, the method shown in the above (1) lacks practicality. Moreover, in the method shown in said (2), the force which presses the sealing member 40 to the cyclic | annular recessed part 26 becomes weak in the location which joined both ends of the wire, for example, entangled both ends. For this reason, when the gas pressure of the gas released from the safety valve 28 and confined by the sealing member 40 is significantly increased to a high pressure, the sealing member is used in a portion where the pressing force by the wire is weakened. Gas easily enters the close contact interface between 40 and the annular recess 26 to form a leakage path, and gas leakage to the outside is likely to occur. Therefore, the method shown in (2) also lacks practicality.

  The number of windings of the coil spring 60 needs to exceed at least one in the state after attachment. This is because, when the number of windings exceeds 1, the occurrence of the same problem as the method shown in (1) above can be surely prevented. In consideration of the loosening of the coil spring 60 due to a decrease in tightening force over time, the number of windings is preferably 1.1 times or more and 1.3 times or more in order to ensure a margin. More preferred. However, the number of windings is particularly preferably two or more as shown in FIGS. By setting the number of windings to two or more, the area where the sealing member 40 and the annular recess 26 are in close contact by the pressing force of the coil spring 60 increases in proportion to the number of windings. For this reason, even if the gas pressure of the gas released from the safety valve 28 and confined inside the sealing member 40 becomes high, it is difficult to form a leak path at the close contact interface between the sealing member 40 and the annular recess 26. It is possible to more reliably prevent gas from leaking outside. The upper limit of the number of windings is not particularly limited, but is preferably 5 times or less and more preferably 3 times or less from the practical point of view such as the width of the annular recess 26 and securing the productivity of the electrolytic capacitor 10. In addition, the number of turns of the coil spring 60 in the state before attachment is not particularly limited as long as the number of turns within the above-described range can be realized in the state after attachment, but from the viewpoint of ease of handling and practical use, it is 2 to It is preferable to be within the range of 3 times.

  Further, as shown in FIGS. 1 and 4, at least the end portion 62A closer to the safety valve 28 side of the coil wire 62 constituting the coil spring 60 is separated from the outer surface 48 of the sealing member 40. It is preferable to arrange in the position. 4 shows a case where the coil spring 60 shown in FIGS. 1 and 2 is viewed from the side where the safety valve 28 is arranged in FIG. 1 and FIG. 2 (hereinafter sometimes referred to as “upper side”). It is a top view. Here, both end portions 62 </ b> A and 62 </ b> B of the coil spring 60 are disposed so as to face the outer side than the winding direction R of the coil wire 62. That is, both end portions 62A and 62B are located away from the inner peripheral surface 64 of the spring coil 60 that comes into contact with the sealing member 40 when the electrolytic capacitor 10 is assembled. That is, when the electrolytic capacitor 10 is assembled, both end portions 62A and 62B are disposed at positions separated from the outer surface 48 of the sealing member 40. Therefore, by adopting the above-described configuration, when the sealing member 40 located above the coil spring 60 is expanded by the gas released from the safety valve 28, the end portion 62A of the coil wire is sealed with the sealing member 40. The sealing member 40 is not damaged by biting into the outer surface 48. Further, when the coil spring 60 is attached, the risk of causing a similar laceration in the sealing member 40 is reduced. For this reason, the gas leak resulting from the tear of the sealing member 40 can be prevented reliably.

  In order to obtain the above-described effects, only the end 62A closer to the safety valve 28 among the both ends 62A and 62B may be disposed at a position separated from the outer surface 48 of the sealing member 40. However, from a practical point of view such as ensuring the ease of assembling work, as shown in FIG. 4, both end portions 62 </ b> A and 62 </ b> B are arranged so as to face outward from the winding direction R of the coil wire 62. When the electrolytic capacitor 10 is assembled, it is preferable that the both end portions 62A and 62B are arranged at positions separated from the outer surface 48 of the sealing member 40.

The thickness of the sealing member 40 is appropriately selected within a range where the sealing member 40 expands appropriately according to pressure and does not rupture when gas is released from the safety valve 28. When this thickness is determined, it is appropriately determined in consideration of the strength and stretching characteristics of the material constituting the sealing member 40. The thickness of the sealing member 40, Ru varied thickness depending on the site of each constituting the sealing member 40 as illustrated in FIG 3. In FIG. 3, the portions denoted by reference numerals 44 </ b> A and 44 </ b> B are portions on the opening 42 side, and the vicinity of the portion where the coil spring 60 is disposed on the outer surface 48 and is closely attached to the annular recess 26 Constitutes a coil spring receiving portion 44B, and a portion closer to the opening 42 than the coil spring receiving portion 44B constitutes an opening vicinity portion 44A. Further, the portion opposite to the opening 42 with respect to the coil spring receiving portion 44B constitutes the upper portion 44C.

In the electrolytic capacitor 10 of the present embodiment, as shown in FIG. 3, the opening of the sealing member 40 is larger than the thickness of the vicinity of the portion (coil spring receiving portion 44 </ b> B) that is closely fixed to the annular recess 26 by the coil spring 60. the thickness of the part 42 side portion (near the opening portion 44A), you thicker. The “thickness” referred to here means the thickness before the electrolytic capacitor 10 is assembled (thickness in the state shown in FIG. 3). By adopting such a configuration, even if the gas pressure of the gas released from the safety valve 28 becomes higher and a force that pulls the sealing member 40 upward acts, the opening vicinity portion 44A is The coil spring 60 and the annular recess 26 are caught. Therefore, it is possible to prevent the sealing member 40 from falling off from the electrolytic capacitor body 20 and leaking gas to the outside.

  Further, when the coil spring 60 has both end portions 62A and 62B facing outward from the winding direction R of the coil wire 62 as shown in FIG. 4, the both end portions 62A and 62B are electrolyzed as shown in FIG. In the diametrical direction of the capacitor 10, it is preferably disposed so as to be located on the inner side of the outer surface 48 </ b> A (the two-dot chain line in FIG. 5) in the opening vicinity portion 44 </ b> A of the sealing member 40. Here, FIG. 5 is a schematic diagram showing an example of the positional relationship between both end portions of the coil spring in the diameter direction of the electrolytic capacitor of the present embodiment and the outer surface in the vicinity of the opening of the sealing member. The description of members other than these is omitted. This reliably prevents the sealing member 40 from being damaged when the electrolytic capacitor 10 is shipped from the factory. The reason is as follows. First, when the electrolytic capacitor 10 manufactured in a factory is transferred to a user, the outer peripheral surfaces of the electrolytic capacitors 10 are close to or in contact with each other after aligning the directions of the lead terminals 32A and 32B of the individual electrolytic capacitors 10. In general, the electrolytic capacitors 10 are packed in a densely arranged state. For this reason, if both end portions 62 </ b> A and 62 </ b> B of the coil spring 60 are directed outward from the winding direction R of the coil wire 62, the sealing member 40 of the adjacent electrolytic capacitor 10 may be damaged. However, when the above-described configuration is employed, the electrolytic capacitor 10 is maintained in the space between the opening vicinity portions 44 </ b> A of the sealing member 40. For this reason, generation | occurrence | production of the above problems can be suppressed.

  As described above, by adopting a combination of the configuration shown in FIG. 4 and the configuration shown in FIG. 5, when the gas is released into the sealing member 40 or when the electrolytic capacitor 10 is transferred, the sealing member 40 can be surely prevented from being damaged. Note that the same effect is obtained when both end portions 72A and 72B of the coil spring 70 are connected to only the outer peripheral surface 76 of the coil wire 72 along the winding direction R of the coil wire 72 around which the inner peripheral surface 74 is wound. It can also be obtained in the case of adopting a configuration arranged so as to be in close contact (FIG. 6). Here, FIG. 6 is a schematic view showing another example of a coil spring used in the electrolytic capacitor of the present embodiment, in which the upper part of FIG. 6 shows a plan view of the coil spring and the lower part shows a side view. In this case, since both end portions 72A and 72B are in contact with only the outer peripheral surface 76 of the coil wire 72, even if the sealing member 40 expands when gas is released into the sealing member 40, the sealing is performed. The surface of the stop member 40 is not damaged. In addition, both end portions 72A and 72B are in close contact with the outer peripheral surface 76 along the winding direction of the coil wire 72, and do not face the outside in the winding direction of the coil wire 72. For this reason, in the diametrical direction of the electrolytic capacitor 10, even when both end portions 72A and 72B of the coil spring 70 are not located on the inner side of the outer surface 48A in the opening vicinity portion 44A of the sealing member 40 as illustrated in FIG. When the electrolytic capacitor 10 is transferred, it can be prevented that both end portions 72A and 72B come into contact with the surface of the sealing member 40 of the adjacent electrolytic capacitor 10 so as to bite. Therefore, it is possible to suppress the sealing member 40 from being damaged when the electrolytic capacitor 10 is transferred.

Moreover, in the electrolytic capacitor 10 of this embodiment, as shown in FIG. 3, the thickness of the vicinity of the part (coil spring receiving part 44B) of the sealing member 40 which is closely fixed to the annular recess 26 by the coil spring 60 is fixed. also, it thinner the thickness of the portion opposite to the opening 42 (upper portion 44C) with respect to the vicinity. The “thickness” referred to here means the thickness before the electrolytic capacitor 10 is assembled (thickness in the state shown in FIG. 3). Thereby, when the gas is released from the safety valve 28, the gas is more surely leaked to the outside even if the gas pressure of the gas sealed between the sealing member 40 and the electrolytic capacitor body 20 becomes high. Can be prevented.

  The reason is as follows. That is, generally, the cylindrical case 24 constituting the electrolytic capacitor body 20 has a circular cross section perpendicular to the axial direction including the annular recess 26, but strictly speaking, it is not a perfect circle. In many cases, it has a circular shape with a distortion. For this reason, when the thickness of the sealing member 40 is too thin, even if the sealing member 40 is pressed against the annular recess 26 by the coil spring 60, the adhesion between the sealing member 40 and the annular recess 26 is partially reduced. However, when a gap is formed in this portion or a high pressure is applied even if no gap is generated, a gas leak path is easily formed. In this sense, it is desirable that the thickness of the sealing member 40 is thicker (first need).

  On the other hand, when the gas discharged from the safety valve 28 and sealed between the sealing member 40 and the electrolytic capacitor body 20 reaches a high pressure, the annular recess 26 and the sealing member 40 are in close contact with each other by the coil spring 60. It breaks through the surface and becomes easy to leak outside. In order to prevent such gas leakage, it is necessary that the sealing member 40 can rapidly expand before the gas pressure of the gas sealed between the sealing member 40 and the electrolytic capacitor body 20 becomes high. is there. In this sense, the thickness of the sealing member 40 is preferably as thin as possible without causing rupture during expansion (second need). In addition, when the electrolytic capacitor 10 is arranged on the circuit board, the size of the electrolytic capacitor 10 is often restricted due to the positional relationship with other components and the size of the arrangement space. Also from this point, the thinner the sealing member 40, the better (third need).

  Therefore, if the thickness of the entire sealing member 40 is determined so as to satisfy one of the needs, it may be difficult to satisfy the other need, and as a result, gas leakage may easily occur. However, as described above, if the thickness of the upper portion 44C is made relatively thinner than the thickness of the coil spring receiving portion 44B, all the above-described needs can be balanced and balanced. For this reason, as a result, it is possible to more reliably prevent gas from leaking to the outside while preventing the electrolytic capacitor 10 from being enlarged.

  In addition, the sealing member 40 has an inner surface 46 of the sealing member 40 and an outer surface of the electrolytic capacitor body 20 (cylindrical case 24) except for a portion pressed by the coil spring 60 so as to be in close contact with the annular recess 26. It may be separated. However, as shown in FIG. 2, it is particularly preferable that the entire inner surface 46 of the sealing member 40 is in close contact with the outer surface of the cylindrical case 24. When such a configuration is adopted, the volume is equal to the size of the electrolytic capacitor main body 20 plus the thickness of the sealing member 40 compared to a normal electrolytic capacitor that does not include a sealing member for preventing gas leakage. However, since it increases only, the enlargement of the electrolytic capacitor 10 can be prevented. In addition to this, as shown in Patent Documents 1 and 2, the electrolytic capacitor body is significantly smaller than a cap provided with a bellows-like stretchable part or a bag-like member as a sealing member. Can be Here, “all the inner surface 46 of the sealing member 40 is substantially in close contact with the outer surface of the cylindrical case 24” (1) all of the inner surface 46 is completely in close contact with the outer surface of the cylindrical case 24 without any gap. (2) On the outer surface of the cylindrical case 24, an uneven portion (for example, a safety valve 28 formed in a groove shape in FIG. 2) is partially formed on the outer surface of the cylindrical case 24 except for the annular recess 26. In the case where the inner surface 46 of the sealing member 40 is closely attached to the outer surface of the cylindrical case 24 with no gap, the electrolytic capacitor body 20 is attached so as to cover the sealing member 40 while applying tension. This also means a case where a minute gap is generated in the uneven portion or its periphery.

-Circuit boards and electronic equipment-
The electrolytic capacitor 10 of the present embodiment described above can be used as a circuit board capacitor including at least one capacitor. With such a circuit board, gas leakage can be prevented and a capacitor in which gas is generated can be easily found. In addition, the gas or electrolyte does not scatter around and does not adversely affect other electronic components on the circuit board. Therefore, it is possible to repair and reuse the circuit board by replacing only the failed electrolytic capacitor on the circuit board. In addition, the electrolytic capacitor 10 of the present embodiment can also be used as a capacitor for electronic equipment including at least one capacitor. In this case, a circuit board provided with the electrolytic capacitor 10 of this embodiment can also be used for an electronic device. Such an electronic device is not particularly limited as long as it is a known electronic device using a capacitor. For example, various OA devices such as a copying machine, various communication devices such as a mobile phone, and various display devices such as a liquid crystal display. , Computers, lighting equipment, and the like. In such an electronic device, when an electrolytic capacitor breaks down, generation of gas from the electronic device can be prevented, and it is not mistaken for a fire. In addition, it is possible to discover at a glance which electronic component in the electronic device has failed.

  The above-described embodiment of the present invention is a preferred example of the present invention, but various modifications can be made without departing from the gist of the present invention. For example, although the electrolytic capacitor 10 having the annular recess 26 is shown in the above-described example, the sealing member 40 and the coil spring 60 can be used even in the case of a simple cylindrical case without the annular recess 26. Further, instead of the coil spring 60, a linear member such as a wire or a string may be wound twice or more along the annular recess 26. In this case, both ends of the linear member are fixed by twisting or tying them. When the linear member is wound twice or more in this way, the linear member strongly tightens the sealing member 40 in a portion where the linear member is wound at least once. For this reason, it can prevent that the vaporized electrolyte solution leaks outside. Moreover, although the electrolytic capacitor 10 is cylindrical, it can be applied to other types of electrolytic capacitors. In addition to the electrolytic capacitor, the present invention can be applied to a capacitor having a risk of the contents inside the capacitor being discharged to the outside.

DESCRIPTION OF SYMBOLS 10 Electrolytic capacitor 20 Electrolytic capacitor main body 22 Electrolytic capacitor element 24 Cylindrical case 24A Outer peripheral surface 24B End surface 24C Opening portion 26 Annular recess 28 Safety valve 30 Sealing member 32A, 32B Lead terminal 40 Sealing member 42 Opening portion 44A Opening vicinity portion 44B Coil spring Receiving part 44C Upper part 46 Inner surface 48, 48A Outer surface 60 Coil spring 62 Coil wire 62A, 62B End 64 Inner peripheral surface 70 Coil spring 72 Coil wire 72A, 72B End 74 Inner peripheral surface 76 Outer peripheral surface

Claims (6)

An electrolytic capacitor element, a cylindrical case that accommodates the electrolytic capacitor element therein, an annular recess provided on an outer peripheral surface of the cylindrical case along a circumferential direction thereof, an outer surface of the cylindrical case, and In an electrolytic capacitor having a safety valve provided at a position not overlapping with the annular recess,
Covers the cylindrical case so as to cut off at least the safety valve provided on the outer surface of the cylindrical case and its surroundings from the outside atmosphere, and the opening side closely contacts at least the annular recess. An inflatable sealing member fixed to the outer surface of the cylindrical case
Winding so that the number of windings exceeds one in the circumferential direction of the cylindrical case so as to be disposed along the annular recess and sandwich the opening side of the sealing member with the annular recess. Coil springs,
Bei to give a,
Of the sealing member, the thickness of the portion on the opening side is greater than the thickness in the vicinity of the portion that is in close contact with and fixed to the annular recess by the coil spring, and
Of the sealing member, the thickness of the portion on the side opposite to the opening with respect to the vicinity of the portion is thinner than the thickness near the portion that is closely fixed to the annular recess by the coil spring. Electrolytic capacitor. The electrolytic capacitor according to claim 1,
The electrolytic capacitor is characterized in that the coil spring is wound two to five times. The electrolytic capacitor according to claim 1 or 2,
The electrolytic capacitor characterized in that at least an end portion closer to the safety valve side among the both end portions of the coil wire constituting the coil spring is disposed at a position separated from the outer surface of the sealing member. In the electrolytic capacitor as described in any one of Claims 1-3 ,
The electrolytic capacitor characterized in that the inner surface of the sealing member is substantially in close contact with the outer surface of the cylindrical case. A circuit board comprising the electrolytic capacitor according to any one of claims 1 to 4 . An electronic apparatus comprising the electrolytic capacitor according to any one of claims 1-4.

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