JP2018125465A - Electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic capacitor which can inhibit characteristic change even after long term use under a high temperature environment.SOLUTION: An electrolytic capacitor includes: a cylindrical case having an opening at one end and extending in an axial direction; a capacitor element which is stored in the case with an electrolytic solution; a sealing body attached to the opening of the case; a seat plate which covers the opening with an opening side end part of an outer peripheral surface of the case; and an annular packing attached to an outer periphery of the case. The seating plate contacts with the outer peripheral surface of the case and the opening side end part of the case and covers at least part of the annular packing while contacting therewith from the radial outer side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electrolytic capacitor.

  Conventionally used general electrolytic capacitors are described in Patent Document 1, for example. In the electrolytic capacitor described in Patent Document 1, a capacitor element is inserted together with an electrolytic solution into an exterior case having an opening, and a sealing body is attached to the opening. And the frame part is arrange | positioned at the end surface of the said sealing body, and the upper end part of the said frame part has covered a part of crimping part of the said exterior case side surface. And the upper end part of the said frame part is heat-deformed along the said caulking part, and the whole said frame part is moored to the said exterior case.

  When the electrolytic capacitor configured as described above is soldered to the substrate, the inside of the outer case is heated by heat during soldering, and the pressure inside the outer case increases. And if the pressure inside the said exterior case rises, the force pushed out of the said exterior case will act with respect to the said sealing body. In the above-described electrolytic capacitor, the upper end portion of the frame portion covers a part of the caulking portion and is thermally deformed, thereby suppressing the sealing body from protruding to the outside.

JP-A 61-59816

  In recent years, there has been an increase in the amount of heat generated by the semiconductor element accompanying an increase in the processing speed of a semiconductor element (such as a CPU) mounted together with the electrolytic capacitor, and a demand for using the electrolytic capacitor in the vicinity of a driving unit of an automobile. Electrolytic capacitors have been used for a long time in a high temperature environment that has not been considered in the past.

  When a conventional electrolytic capacitor is used in a high temperature environment for a long time, the sealing body and the frame portion deteriorate, and a gap is formed between these members and the outer case. In addition, the electrolyte in the outer case is heated to increase the pressure in the electrolytic case, and the solvent may evaporate or the electrolyte may leak out of the outer case.

  In the electrolytic capacitor, when the internal electrolytic solution decreases due to evaporation of the solvent and / or leakage of the electrolytic solution, a characteristic change as the electrolytic capacitor (for example, an increase in internal resistance) occurs, and electronic devices, automobiles, etc. There is a risk of performance degradation or malfunction.

  An object of this invention is to provide the electrolytic capacitor which can suppress a characteristic change even if it uses it for a long period of time in a high temperature environment.

  In order to achieve the above object, an electrolytic capacitor according to the present invention includes a cylindrical case extending in the axial direction and having an opening at one end in the axial direction, a capacitor element housed in the case together with the electrolyte, and the case A sealing body attached to the opening, a seat plate that covers the opening together with an end on the opening side of the outer peripheral surface of the case, and an annular packing attached to the outer peripheral surface of the case, The seat plate is an injection-molded body of synthetic resin, and contacts the outer peripheral surface of the case and the end portion on the opening side of the case, and covers at least a part of the annular packing while contacting from the radially outer side. It is characterized by that.

  According to this configuration, since the annular packing is used, the gap between the seat plate and the case is sealed by the annular packing, so that solvent evaporation and / or electrolyte leakage to the outside of the case are suppressed. it can. Further, since the gap between the seat plate and the case is sealed, it is difficult for external moisture to enter the case, that is, moisture resistance can be improved. Furthermore, the annular packing portion is interposed between the case and the seat plate, so that the integration of the seat plate and the case proceeds. As a result, the vibration resistance, for example, the vibration resistance for the connection terminal of the capacitor element is increased. Can also be improved.

  The said structure WHEREIN: The said annular packing may protrude in the radial direction outer side rather than the outer peripheral surface of the said case. By comprising in this way, it is possible to improve the sealing performance of an annular packing and a seat plate.

  The said structure WHEREIN: At least one part of the axial direction one end side of the said annular packing may protrude in the said axial direction from the front-end | tip of the axial direction one end side of the said seat plate. By comprising in this way, it is possible to seal the clearance gap between a seat board and a case more reliably.

  The said structure WHEREIN: The said seat plate and the said annular packing may be formed with the material whose heat resistance is higher than the said sealing body. By comprising in this way, even if a sealing body heat-deteriorates, evaporation of a solvent and / or electrolyte solution leakage to the exterior of a case can be suppressed by a seat plate and an annular packing.

  In the above configuration, the case includes an annular protrusion that protrudes inward in the radial direction of the case at a portion opposed to the sealing body in the radial direction on an inner peripheral surface, and the sealing body is pressed by the protrusion. It's okay. By being configured in this way, even when the pressure inside the case rises due to temperature rise, the sealing body can be suppressed from being pushed out of the case.

  In the above-described configuration, the case includes an annular recess that is recessed inward and continuous in the circumferential direction on the outer peripheral surface of the portion where the entry portion is formed, and the annular packing and the seat plate are disposed inside the annular recess. At least a part of at least one of them may be arranged. By comprising in this way, the evaporation of the solvent to the exterior of a case and / or electrolyte solution leakage by the temperature rise of an electrolytic capacitor can be suppressed.

  The said structure WHEREIN: The said seat board has a terminal hole which the said connection terminal penetrates, The sealing packing which seals the said terminal hole may be mounted | worn with the said terminal hole. By comprising in this way, the evaporation of the solvent to the exterior of a case and / or electrolyte solution leakage by the temperature rise of an electrolytic capacitor can be suppressed.

  In the above configuration, the annular packing may be black and the case may be white or gray. By comprising in this way, in the manufacturing process of an electrolytic capacitor, it can be visually recognized easily whether the annular packing was attached to the case. Therefore, it is possible to manufacture an electrolytic capacitor in which the solvent hardly evaporates and / or the electrolyte does not leak even when used in a high temperature environment for a long time. An example of the material constituting the annular packing is a black rubber material. Examples of the material constituting the case include an aluminum-based metal material (aluminum, aluminum alloy, etc.).

  ADVANTAGE OF THE INVENTION According to this invention, the electrolytic capacitor which can suppress the characteristic change by long-term use in a high temperature environment can be provided. Further, since the gap between the seat plate and the case is sealed, it is difficult for external moisture to enter the case, that is, moisture resistance can be improved. Furthermore, the annular packing portion is interposed between the case and the seat plate, so that the integration of the seat plate and the case proceeds. As a result, the vibration resistance, for example, the vibration resistance for the connection terminal of the capacitor element is increased. Can also be improved.

It is a perspective view which shows the electrolytic capacitor of embodiment of this invention. It is a front view of the electrolytic capacitor shown in FIG. It is sectional drawing of the electrolytic capacitor shown in FIG. It is a bottom view of the electrolytic capacitor shown in FIG. It is sectional drawing which shows the state in the middle of manufacture of the electrolytic capacitor which concerns on this embodiment. It is a top view which shows the state in the middle of manufacture of the electrolytic capacitor shown in FIG. It is an expanded sectional view of the other example of the electrolytic capacitor concerning this invention. It is sectional drawing of the further another example of the electrolytic capacitor concerning this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view of an electrolytic capacitor according to an embodiment of the present invention. FIG. 2 is a front view of the electrolytic capacitor shown in FIG. FIG. 3 is a cross-sectional view of the electrolytic capacitor shown in FIG. FIG. 4 is a bottom view of the electrolytic capacitor shown in FIG. FIG. 5 is a cross-sectional view showing a state during the production of the electrolytic capacitor shown in FIG. FIG. 6 is a plan view showing a state in the middle of manufacturing the electrolytic capacitor shown in FIG. In the following description, “upper and lower” refers to upward or downward with reference to the electrolytic capacitor shown in FIGS. 2 and 3. In the electrolytic capacitor shown in FIG. 5, “front and rear” refers to the front side on the front side and the back side on the rear side. In the electrolytic capacitor shown in FIG. 6, the lower side indicates the front and the upper side indicates the rear.

  As shown in FIGS. 1 to 4, the electrolytic capacitor 100 includes a case 1, a capacitor element 3, a sealing body 4, a first connection terminal 6, a second connection terminal 7, a seat plate 8, and an annular packing. 11 and sealing packing 12.

  As shown in FIGS. 1 to 3, the case 1 is a cylindrical case having an opening 2 at one end (here, the lower end). Moreover, the edge part on the opposite side to the opening part 2 of the case 1 is closed, ie, the case 1 is the bottomed cylindrical shape which the lower part opened. The case 1 is made of, for example, aluminum, and the surface is white or gray. In addition, it is not limited to the product made from aluminum, The material which can suppress the corrosion by electrolyte solution which a solvent does not evaporate easily and an electrolyte solution does not leak easily can be employ | adopted widely.

  The capacitor element 3 is accommodated inside the case 1. The capacitor element 3 has a configuration in which a separator is interposed between an inner layer and an outer layer. The first connection terminal 6 is connected to the inner layer, and the second connection terminal 7 is connected to the outer layer. The case 1 contains an electrolytic solution together with the capacitor element 3. The inner layer, the outer layer, the separator, and the electrolytic solution have known configurations, and details are omitted.

  The sealing body 4 is made of rubber and is fitted into the opening 2 of the case 1. As shown in FIG. 3, the end of the opening 2 of the case 1 is folded inward. By this folding, the sealing body 4 is prevented from jumping out of the case 1. Further, in the vicinity of the opening 2 of the case 1, a plunging portion 5 that bulges inward is formed. The entry portion 5 is continuous in the circumferential direction and is annular. The rush portion 5 rushes into the outer peripheral portion of the sealing body 4. Thereby, the adhesiveness of the inner surface of case 1 and the outer peripheral part of the sealing body 4 becomes high, and the evaporation of the solvent to the exterior of case 1 and / or electrolyte solution leakage are suppressed. The outer peripheral surface of the case 1 is thin. Therefore, an annular recess 10 that is recessed inward is formed on the outer peripheral surface of the case 1 by forming the intrusion portion 5 that enters the inside of the case 1. The annular recess 10 is formed in an annular shape, like the rush portion 5.

  The sealing body 4 includes through holes 41 and 42 through which the first connection terminal 6 and the second connection terminal 7 penetrate from the inside of the case 1 to the outside. The first connection terminal 6 and the through hole 41 are in close contact with each other, and the second connection terminal 7 and the through hole 42 are in close contact with each other, so that the evaporation of the solvent and / or the leakage of the electrolyte is suppressed.

  The seat plate 8 includes a recessed hole 80 and through holes 81 and 82. The recessed hole 80 has an opening upward. The case 1 is inserted into the recessed hole 80. In the case 1, the opening 2 is disposed inside the recessed hole 80, and the inner peripheral surface of the recessed hole 80 is in contact with a portion of the outer peripheral surface of the case 1 on the opening 2 side. Thus, the seat plate 8 covers the outer side of the opening 2 of the case 1 and the outer peripheral portion of the case 1 on the opening 2 side of the case 1. The seat plate 8 is made of, for example, a synthetic resin injection-molded body.

  The through holes 81 and 82 penetrate from the bottom surface of the recessed hole 80 to the lower surface of the seat plate 8. The first connection terminal 6 passes through the through hole 81, and the second connection terminal 7 passes through the through hole 82. The sealing packing 12 is attached to the through holes 81 and 82. The sealing packing 12 is made of rubber, for example, and the outer surface is in contact with the inner peripheral surface of the through hole 81 or 82. Further, the first connection terminal 6 penetrates through one sealing packing 12, and the second connection terminal 7 penetrates the other sealing packing 12. Thereby, the sealing packing 12 suppresses that the solvent evaporates from the through holes 81 and 82 or the electrolyte solution leaks.

  Two grooves 91 and 92 communicating with one of the through holes 81 and 82 are provided on the lower surface of the seat plate 8. The grooves 91 and 92 respectively extend toward the opposite side surface of the seat plate 8. The tip portion protruding from the through hole 81 of the first connection terminal 6 is bent along the groove 91. Further, the tip portion protruding from the through hole 82 of the second connection terminal 7 is bent along the groove 92. The first connection terminal 6 and the second connection terminal 7 are arranged in the grooves 91 and 92, and a part of the first connection terminal 6 and the second connection terminal 7 protrudes to the outside (lower side) of the grooves 91 and 92. Thereby, soldering to the wiring pattern formed on the surface of the circuit board (not shown) can be performed. In addition, although the electrolytic capacitor 100 of this embodiment is set as the structure which can be mounted in the circuit board for surface mounting which mounts an electronic component on the surface, it is not limited to this. For example, when the electronic component terminal is used for a circuit board for mounting a through hole that penetrates a through hole provided in the circuit board and solders the penetrating tip, the first connection terminal 6 and the second connection terminal 7 are: There is no need to bend it.

  As shown in FIG. 3, an annular recess 10 is formed on the outer peripheral surface of the case 1. The annular recess 10 has a cross-sectional shape that is recessed inward and curved along the axial direction of the case 1. That is, the annular recess 10 has a concave shape in which the upper end and the lower end in the axial direction have the same size as the outer peripheral surface of the case 1 and the outer shape decreases from the upper end and the lower end toward the axial direction. An annular packing 11 made of heat-resistant rubber such as silicone rubber is attached to the outside of the case 1. The annular packing 11 is fitted in the annular recess 10.

  The annular packing 11 is in close contact with at least the axially intermediate portion of the annular recess 10. The annular packing 11 is formed of, for example, heat resistant rubber such as silicone rubber. The annular packing 11 is elastically deformable at least in the radial direction. That is, the annular packing 11 can be brought into close contact by being attached so as to tighten the annular recess 10 with an elastic force.

  The material constituting the annular puncturing 11 is not limited to silicone rubber, and is not easily denatured even in a high-temperature environment as described later, and the gap between the object to be attached (here, the case 1 and the seat plate 8). A wide range of materials that are less likely to deteriorate the sealing performance can be used. The annular packing 11 is black, and the radially inner side is disposed in the annular recess 10 and the radially outer side protrudes outward from the outer peripheral surface of the case 1 (FIG. 3 and the like). reference). In addition, the outer peripheral surface of the annular packing 11 that protrudes radially outward from the outer peripheral surface of the case 1 is cylindrical, that is, the cut end surface cut along the axis is linear.

  As shown in FIG. 3, when the recessed hole 80 of the seat plate 8 comes into contact with the bottom surface of the opening 2 side of the case 1, the inner surface of the recessed hole 80 is radially outward with respect to the annular recessed part 10. Located in. The inner surface of the recessed hole 80 covers at least a part of the outer peripheral surface of the annular packing 11 that fits in the annular recess 10. The inner surface of the recessed hole 80 is in close contact with the outer peripheral surface of the annular packing 11.

  As described above, the annular packing 11 is in close contact with the annular recess 10 of the case 1 on the inner peripheral surface, and is in close contact with the inner surface of the recessed hole 80 of the seat plate 8 on the outer peripheral surface. That is, the outer peripheral surface of the case 1 and the inner surface of the recessed hole 80 of the seat plate 8 are sealed by the annular packing 11, and solvent evaporation and / or electrolyte leakage from the gap between the case 1 and the seat plate 8 are prevented. It is suppressed.

  Next, a method for manufacturing the electrolytic capacitor according to the present embodiment will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing a state during the production of the electrolytic capacitor according to the present embodiment. FIG. 6 is a plan view showing a state in the middle of manufacturing the electrolytic capacitor shown in FIG.

  In the manufacturing method of the electrolytic capacitor 100 according to the present embodiment, first, the capacitor element 3 and the electrolytic solution (not shown) are accommodated in the case 1. And the sealing body 4 is inserted in the opening part 2 of the case 1, and the outer peripheral part facing the sealing body 4 of the case 1 is annularly pushed inside. As a result, the inner surface of the case 1 is formed with a protruding portion 5 that protrudes inward, and the outer peripheral surface of the case 1 is formed with an annular concave portion 10 that is recessed inward. Thereafter, the end of the opening 2 of the case 1 is folded inward (see FIG. 3). Thereafter, the annular packing 11 is attached to the annular recess 10.

  As shown in FIGS. 5 and 6, a mold 13 surrounding the lower portion of the case 1 is attached. The mold 13 has division parts 13F and 13R that can be divided (here, can be divided front and rear), and sandwich the case 1 from front and rear. The mold 13 has a case hole 130 formed on the upper surface when the divided portion 13F and the divided portion 13R are combined, and a terminal hole formed on the lower surface through which the first connection terminal 6 and the second connection terminal 7 pass, respectively. 131 and 132. When the case 1 is sandwiched between the divided portions 13F and 13R, the case 1 is exposed upward from the case hole 130. On the other hand, the first connection terminal 6 protruding downward from the case 1 passes through the terminal hole 131, and the second connection terminal 7 passes through the terminal hole 132.

  At this time, the sealing packing 12 is attached inside the mold 13 of the first connection terminal 6 and the second connection terminal 7. That is, two sealing packings 12 are arranged inside the mold 13, and each sealing packing 12 is fitted around the first connection terminal 6 and the second connection terminal 7, and the mold 13 Contact the inside of the bottom. That is, the sealing packing 12 is attached to the first connection terminal 6 and the second connection terminal 7, and comes into contact with the inside of the bottom surface of the mold 13, so that the resin terminal hole injected into the mold 13 is used. Outflow from 131 and 132 is suppressed.

  Although the annular packing 11 is mounted in the annular recess 10, its outer peripheral surface protrudes radially outward from the outer peripheral surface of the case 1 as shown in FIG. 5. Therefore, when the case 1 is sandwiched between the divided portions 13F and 13R of the mold 13, the inner surface of the case hole 130 presses the outer peripheral surface of the annular packing 11 in the radial direction. Thereby, since the mold 13 and the annular packing 11 are in close contact with each other, the molten synthetic resin injected into the mold is less likely to leak from the gap between the annular packing 11 and the case hole 130. Note that the case hole 130 contacts the upper side of the axially intermediate portion of the radially outer surface of the annular packing 11.

  In the electrolytic capacitor 100 of the present embodiment, the annular packing 11 is black. And although the annular packing 11 is externally fitted by the annular recessed part 10, the outer peripheral surface has protruded outward rather than the outer peripheral surface of the case 1. FIG. And since the case 1 is made into the white type | system | group or a gray type | system | group, the confirmation of the state which the metal mold | die 13 contact | abutted to the annular packing 11 of the black type and the state which protruded outward becomes easy. That is, it is possible to improve the workability of mounting the mold 13 when the seat plate 8 is formed.

  The mold 13 is provided with a filling hole (not shown), and a synthetic resin melted from the filling hole is injected into the mold 13 (injection molding). As a result, the synthetic resin closely adheres to the outside of the opening 2 of the case 1 and the outer peripheral portion of the case 1 on the opening side by the synthetic resin in the mold 13. Then, after the synthetic resin is cured, the mold 13 is removed. The synthetic resin injected into the mold 13 and cured constitutes the seat plate 8. That is, by configuring the seat plate 8 by injection molding, the seat plate 8 can be brought into close contact with the opening 2 of the case 1 and the outer peripheral portion on the opening side of the case 1. Thereby, the evaporation of the solvent to the outside of the case 1 and / or the electrolyte leakage is suppressed.

  The upper end of the contact portion between the seat plate 8 and the case 1 is sealed with an annular packing 11. For example, when it is set as the structure which does not provide the annular packing 11, in order to suppress that the resin which fuse | melted from the clearance gap between the case 1 and the metal mold | die 13 flows out at the time of injection molding, the case hole 130 of the metal mold | die 13 is made into the case 1. It is necessary to press strongly against. However, if the force pressing the mold 13 against the case 1 is too strong, the case 1 may be deformed. On the other hand, in this embodiment, an annular packing 11 that can be elastically deformed is attached to the outer peripheral surface (annular recess 10) of the case 1 and the outer peripheral surface of the annular packing 11 is pressed against the case hole 130 of the mold 13 and then injection molding is performed. Is going. Since the annular packing 11 is configured to be elastically deformable, the annular packing 11 is deformed with a smaller force than when the mold 13 is directly attached to the case 1. As a result of this deformation, the annular packing 11 closely contacts the annular recess 10 of the case 1 and also closely contacts the case hole 130 of the mold 13. That is, by using the annular packing 11, the force that pushes the case 1 inward in the radial direction by the mold 13 is reduced, so that deformation of the case 1 can be suppressed.

  As described above, in this embodiment, the sealing body 4 is attached to the opening 2 of the case 1, and the protruding portion 5 in which the portion facing the sealing body 4 of the case 1 in the radial direction is inserted into the inside of the case 1 is provided. The sealing body 4 is closely attached. In addition, by forming the protruding portion 5, the annular recess 11 formed in the outer peripheral portion of the case 1 is fitted from the outside of the case 1 and is closely attached, and the seat plate 8 is attached to the opening portion. 2. The case 1 is in close contact with the end on the opening 2 side and the outer peripheral surface of the annular packing 11. Thereby, even if the electrolytic capacitor 100 is used in a high temperature environment and the pressure inside the case 1 is increased, the evaporation of the solvent and / or the leakage of the electrolytic solution is suppressed. Further, even when the electrolytic capacitor 100 is used for a long time in a high temperature environment and the sealing body 4 is deteriorated due to heat, the outside of the opening 2 of the case 1 and the outer periphery of the case 1 are formed by injection molding. Since it is covered with the plate 8, the evaporation of the solvent and / or the leakage of the electrolytic solution to the outside of the case 1 can be suppressed.

  That is, by forming the seat plate 8 by injection molding, the seat plate 8 itself can be in close contact with the case 1, so even if the sealing body 4 is thermally deteriorated due to long-term use in a high-temperature environment, Since the state in which the outer periphery of the opening 2 and the outer peripheral portion of the case 1 and the seat plate 8 are in close contact with each other is maintained, the evaporation of the solvent to the outside of the case 1 and / or the electrolyte leakage can be suppressed. Therefore, even when the electrolytic capacitor 100 according to the present invention is used for a long time in a high temperature environment, it is possible to suppress deterioration of characteristics as an electrolytic capacitor.

  Further, in the electrolytic capacitor 100 of the present embodiment, the annular packing 11 is externally fitted in the annular recess 10 formed in the outer peripheral portion of the case 1, and at least a part of the outer portion of the case 1 of the annular packing 11 is an injection molded body. It adheres to a part of the seat plate 8 formed by the above. Thereby, it is difficult to form a gap between the seat plate 8 and the case 1 where the solvent evaporates and / or the electrolyte leaks. Also from this point, evaporation of the solvent to the outside of the case 1 and / or leakage of the electrolyte is suppressed.

  That is, in the electrolytic capacitor 100 of the present embodiment, the portion between the case 1 and the seat plate 8 formed by the injection molded body is disposed in the portion where the annular packing 11 disposed in the annular recess 10 of the case 1 is disposed. Further, the annular packing 11 is interposed. Therefore, the airtightness in the opening 2 of the case 1 is enhanced, and as a result, evaporation of the solvent to the outside of the case 1 and / or electrolyte leakage can be suppressed.

  Moreover, in the electrolytic capacitor 100 of this embodiment, since the airtightness in the opening part 2 of case 1 is strengthened, the sealing body 4 is hard to be exposed to external air. As a result, oxidation of the sealing body 4, that is, deterioration is suppressed. Also from this point, evaporation of the solvent and / or electrolyte leakage from the case 1 can be suppressed. Furthermore, by enhancing the airtightness in the opening 2 of the case 1, the moisture resistance with respect to the case 1 is also enhanced.

  Further, a seat plate 8 formed of a synthetic resin injection-molded body closely covers the outer periphery of the opening 2 of the case 1 and the outer peripheral portion of the case 1 on the opening 2 side. Integration of the seat plate 8 and the case 1 proceeds by placing the annular packing 11 portion disposed on the surface between the case 1 and the seat plate 8. As a result, vibration resistance, for example, vibration resistance for the connection terminals 6 and 7 of the capacitor element 3 can be improved.

  As described above, the high temperature environment includes an increase in heat generation due to an increase in the processing speed of electronic components attached to the electronic device, a decrease in heat dissipation due to downsizing of the electronic device, The thing by the use in the vicinity of heat sources, such as a drive part, is mention | raise | lifted.

(Second Embodiment)
Another example of the electrolytic capacitor according to the present invention will be described with reference to the drawings. FIG. 7 is an enlarged cross-sectional view of another example of the electrolytic capacitor according to the present invention. The electrolytic capacitor 101 shown in FIG. 7 has the same configuration as the electrolytic capacitor 100 of the first embodiment, except that the sealing packing 14 is different from the sealing packing 13. Therefore, in the electrolytic capacitor 101, substantially the same parts as those of the electrolytic capacitor 100 are denoted by the same reference numerals, and detailed description of the same parts is omitted.

  The electrolytic capacitor 101 shown in FIG. 7 uses a conical sealing packing 14. Since the side surface of the conical sealing packing 14 is inclined, when the molten synthetic resin is injected into the mold, the pressure by the synthetic resin is directed downward. That is, the sealing packing 14 is directed toward the bottom surface of the mold 13 by the pressure of the synthetic resin. Therefore, the terminal holes 131 and 132 of the mold 13 can be tightly sealed by the sealing packing 14. As a result, it is possible to prevent the synthetic resin from flowing out of the terminal holes 131 and 132 during injection molding, and to improve the airtightness of the first connection terminal 6 and the second connection terminal 7 of the completed electrolytic capacitor 101.

  About an effect | action and an effect, it is the same as 1st Embodiment.

(Third embodiment)
Still another example of the electrolytic capacitor according to the present invention will be described with reference to the drawings. FIG. 8 is a cross-sectional view of still another example of the electrolytic capacitor according to the present invention. The electrolytic capacitor 102 shown in FIG. 8 is different from the electrolytic capacitor 100 of the first embodiment in the seat plate 8B and the annular packing 15. The other portions of the electrolytic capacitor 102 are the same as those of the electrolytic capacitor 100, and substantially the same portions are denoted by the same reference numerals. Further, detailed description of the same portion of the electrolytic capacitor 102 as the electrolytic capacitor 100 is omitted.

  As shown in FIG. 8, in the electrolytic capacitor 102, the annular packing 15 is externally fitted above the annular recess 10 of the case 1, that is, on the side opposite to the opening 2. In the electrolytic capacitor 102 of the present embodiment, the outer peripheral surface of the annular packing 15 protrudes radially outward from the outer peripheral surface of the case 1. And the outer peripheral surface of the annular packing 15 is cylindrical. For this reason, the case hole 130 of the mold 13 can be easily pressed against the case outer portion of the annular packing 15.

  Further, in the electrolytic capacitor 102 of this embodiment, when the synthetic resin is molded by injection molding to form the seat plate 8B, the synthetic resin enters the annular recess 10 and is cured. That is, a protrusion 83 that protrudes inward is formed on the inner peripheral surface of the recessed hole 80 of the seat plate 8 </ b> B, and the protrusion 83 is fitted in the annular recess 10 of the case 1. Therefore, even if a force in a direction away from the lower portion of the case 1 acts on the seat plate 8B, the seat plate 8B is not easily dropped. Thereby, the effect which suppresses jumping out of the sealing body 4 by the raise of the internal pressure of case 1 becomes high.

  In the electrolytic capacitor 102, the annular packing 15 is disposed above the annular recess 10, but may be disposed below the annular recess 10 and to the end on the opening 2 side.

  As described above, the electrolytic capacitor 100 (101, 102) of the present invention has the sealing body 4 attached to the opening 2 of the case 1 and enters the case 1 into a portion corresponding to the sealing body 4 of the case 1. By forming the protruding portion 5, the protruding portion 5 can be brought into close contact with the sealing body 4.

  In the electrolytic capacitor 100 (101, 102) of the present invention, the seat plate 8 (8B) is formed of a synthetic resin injection molded body, and at least a part of the outer portion of the case 1 is the seat plate 8 (8B). It is covered closely with a part of. As described above, the outer portion of the case 1 is covered with the seat plate 8 (8B) of the injection-molded body, so that the airtightness is improved, and the electrolytic capacitor 100 (101, 102) is used for a long time in a high temperature environment. Even if the sealing body 4 is thermally deteriorated, evaporation of the solvent and / or leakage of the electrolyte solution to the outside of the case 1 can be suppressed. That is, by forming the seat plate from the injection-molded body, the seat plate 8 (8B) itself is in close contact with the case 1 and airtightness is increased. The solvent transpiration and / or electrolyte leakage can be suppressed. For example, in the electrolytic capacitor 100 (101, 102) of the present invention, even when the sealing body 4 is used for a long period of time in a high temperature environment where the sealing body 4 is thermally deteriorated, deterioration of characteristics as an electrolytic capacitor can be suppressed.

  Furthermore, the electrolytic capacitor 100 (101, 102) of the present invention has an opening in the annular recess 10 formed in the outer peripheral portion of the case 1 or the opening of the case 1 in the annular recess 10 with the formation of the protruding portion 5 into the case 1. The annular packing 11 (15) is arranged on the second side or on the side opposite to the opening 2. The seat plate 8 (8B) covers and covers at least a part of the outer peripheral portion of the annular packing 11 (15). Thereby, the airtightness of the junction part of the seat board 8 (8B) and the case 1 is also improved. Also from this point, evaporation of the solvent to the outside of the case 1 and / or electrolyte leakage can be suppressed.

  In the electrolytic capacitor 100 (101, 102) of the present invention, an annular packing 11 (15) in the annular recess 10 of the case 1 or on the opposite side of the opening 2 of the case 1 from the annular recess 10 or on the opening 2 side. The annular packing 11 (15) is interposed at the joint between the case and the seat plate 8 (8B). Thereby, the airtightness on the outer side of the case 1 is strengthened, and from this point, the evaporation of the solvent to the outside of the case 1 and / or the electrolyte leakage can be suppressed.

  Further, in the electrolytic capacitor 100 (101, 102) of the present invention, the case plate 1 (8B), the annular packing 11 (15), and the sealing packing 12 (14) formed of a synthetic resin injection-molded body are used. The airtightness with respect to the outside air of the sealing body 4 attached to the opening 2 is increased. As a result, oxidation of the sealing body 4, that is, deterioration can be suppressed, and evaporation of the solvent to the outside of the case 1 and / or electrolyte leakage can be suppressed. Furthermore, by improving the airtightness with respect to the inside of the case 1 as described above, the moisture resistance characteristics with respect to the inside of the case 1 can be enhanced.

  Furthermore, by forming the seat plate 8 (8B) by injection molding of synthetic resin, the outer periphery of the opening 2 side of the case 1 and the outer peripheral part on the opening 2 side of the case 1 are tightly covered, and further, Integration of the seat plate 8 (8B) and the case 1 proceeds by placing the annular packing 11 (15) between the outer peripheral surface and the seat plate 8 (8B). As a result, the vibration resistance, for example, the vibration resistance for the connection terminal of the capacitor element is improved.

100 (101, 102) Electrolytic Capacitor 1 Case 2 Opening 3 Capacitor Element 4 Sealing Body 41 Through Hole 42 Through Hole 5 Penetration 6 First Connection Terminal 7 Second Connection Terminal 8 (8B) Seat Plate 80 Recessed Hole 81 Through Hole 82 Through-hole 83 Entry portion 91 Groove 92 Groove 10 Annular recess 11 Annular packing 12 Sealing packing 13 (13F, 13R) Mold 130 Case hole 131 Terminal hole 132 Terminal hole 14 Sealing packing 15 Annular packing

Claims (9)

A cylindrical case extending in the axial direction and having an opening at one end in the axial direction;
A capacitor element housed together with an electrolyte in the case;
A sealing body attached to the opening of the case;
A seat plate that covers the opening together with an end of the outer peripheral surface of the case on the opening side;
An annular packing attached to the outer peripheral surface of the case,
The seat plate is an injection-molded body made of synthetic resin, and is in contact with the outer peripheral surface of the case and the end portion on the opening side of the case, and covers at least a part of the annular packing from the outside in the radial direction. Electrolytic capacitor characterized by having   The electrolytic capacitor according to claim 1, wherein the annular packing protrudes radially outward from the outer peripheral surface of the case.   The electrolytic capacitor according to claim 1, wherein at least a part of the annular packing on one end side in the axial direction protrudes in the axial direction from a tip on one end side in the axial direction of the seat plate.   The electrolytic capacitor according to any one of claims 1 to 3, wherein the seat plate and the annular packing are formed of a material having higher heat resistance than the sealing body. The case includes an annular projecting portion that projects inward in the radial direction of the case at a portion facing the sealing body in the radial direction on the inner peripheral surface,
The electrolytic capacitor according to claim 1, wherein the sealing body is pressed by the intrusion portion. The case includes an annular recess that is recessed inward and continuous in the circumferential direction on the outer peripheral surface of the portion where the protrusion is formed,
The electrolytic capacitor according to claim 5, wherein at least a part of at least one of the annular packing and the seat plate is disposed inside the annular recess. The seat plate has a terminal hole through which the connection terminal passes,
The electrolytic capacitor according to claim 1, wherein a sealing packing that seals the terminal hole is attached to the terminal hole.   The electrolytic capacitor according to any one of claims 1 to 7, wherein the annular packing is black and the case is white or gray.   The electrolytic capacitor according to claim 8, wherein the annular packing is formed of a black rubber material, and the case is formed of an aluminum metal material.

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