JP2016192482A - Capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve electrical functionality and to obtain high reliability of a capacitor by stabilizing an installation state of capacitor elements within a case member.SOLUTION: A capacitor comprises: a case member (4) housing capacitor elements in two or more housing chambers (12) that are separated by partition walls (10); seal members (seal bodies 8) which seal the housing chambers; and insulation elastic bands (band components 28 and 60) mounted in element outer circumferences of the capacitor elements and deformable. The capacitor element that is swollen by impregnating an electrolyte is pressed in a center direction by the insulation elastic band mounted in the capacitor element, such that spaces (gaps 50 and 52) are provided between the capacitor element and inner wall of the housing chamber.SELECTED DRAWING: Figure 1

Description

The present invention relates to a packaging technique for capacitors such as electric double layer capacitors and electrolytic capacitors, and a manufacturing technique thereof.

  In the capacitors such as electric double layer capacitors and electrolytic capacitors, the area of the electrode foil dominates the capacitance, and there are various types from small to large. For example, it is known that when a desired large capacity cannot be obtained with one capacitor, it can be realized by paralleling the capacitors, and when the withstand voltage of one capacitor is not sufficient, the capacitors may be serialized. ing. Therefore, it is possible to cope with various uses by the connection form of the capacitor. And the modularization provided with a some capacitor and the thing of the form provided with the some element in one case are proposed and implement | achieved.

  With regard to such a capacitor, an electric double layer capacitor including a plurality of capacitor elements and a manufacturing method thereof are known (for example, Patent Document 1).

JP 2002-353078 A

  By the way, when the capacitor element is provided in the outer case and modularized, the electrolytic solution is injected after the capacitor element is inserted into the outer case, but the capacitor element expands by absorbing the electrolytic solution, and the capacitor element The outer edge of the case may be in close contact with the inner wall of the case. In this case, the space ratio in the case is reduced, and the generated gas cannot be accumulated, which may affect the life characteristics of the capacitor. Moreover, although electrolyte solution is injected from the upper direction of a capacitor element, when a capacitor element and the inner wall of a case closely_contact | adhere, electrolyte solution does not reach the bottom face side of a capacitor element, and there exists a subject that work becomes complicated.

  In addition, the capacitor can be charged / discharged with a large current, but an internal resistance such as an electric resistance of an activated carbon layer or an electrolyte of a polarizable electrode forming an element or a contact resistance between components is generated. Since these internal resistances reduce the energy efficiency of the capacitor, it is required to suppress the internal resistance. Causes of this increase in internal resistance include changes in the state of the capacitor element, contact with other components, and the like. For example, in-vehicle capacitors are constantly subjected to vibration during running, acceleration due to acceleration when starting and stopping. There is a problem that the internal resistance may increase due to the influence of vibration on the capacitor element in the case.

  When the capacitor element inside the case is swung due to vibration from the outside, a large stress acts on the electrode layer, the current collector plate, the connection portion with the external terminal, and the like. For this reason, the capacitor element is required to have high retainability so as not to cause breakage in the connection portion with the capacitor element itself, the case, the external terminal, or the like due to repeated vibration.

In view of the above problems, an object of the present invention is to stabilize the installation state of the capacitor element inside the case member to improve the electrical functionality and to obtain the high reliability of the capacitor.

  In order to achieve the above object, one aspect of the capacitor of the present invention includes a case member in which a capacitor element is stored in each of two or more storage chambers partitioned by a partition wall, a sealing portion that seals the storage chamber, An insulating elastic band attached to the outer periphery of the capacitor element and deformable, and the insulating elastic band attached to the capacitor element causes the capacitor element swollen by impregnation with the electrolyte to be pressed in the center direction; A space may be provided between the capacitor element and the inner wall of the storage chamber.

  In the above capacitor, the insulating elastic band may include an expanding portion that expands according to expansion of the capacitor element and changes an inner diameter.

In the capacitor, an inner wall has an inclination so that a cross-sectional area of the storage chamber gradually decreases toward the sealing member, and a portion of the insulating elastic band facing the storage chamber gradually increases in outer diameter toward the sealing member. The capacitor element may be pressed in the center direction by inserting the insulating elastic band into the storage chamber while inclining so as to be smaller and the inclination of the insulating elastic band and the inner wall of the storage chamber are in contact with each other. .

  According to the present invention, any of the following effects can be obtained.

  (1) By maintaining the gap between the storage chamber and the capacitor element, the space ratio in the storage chamber is maintained, so that an allowable space for storing the generated gas is maintained, and the life characteristics are improved. That is, by providing a gap between the capacitor element and the storage chamber, the space ratio can be ensured, and even when gas is suddenly generated, the gas can be stored, and the life characteristics of the product are improved.

  (2) The absorption rate of the electrolytic solution of the capacitor element is improved by the gap. That is, the electrolytic solution is injected from the sealing body side of the capacitor element, but at this time, the electrolytic solution enters the bottom surface side of the capacitor element through the gap around the capacitor element, so that the entire capacitor element is uniformly impregnated with the electrolytic solution. It becomes easy to be done.

  (3) Capacitor elements can be prevented from swinging inside the case against external vibrations.

  (4) By not causing the capacitor to oscillate inside the case, no breakage occurs between the electrode layer of the capacitor element and other parts connected to the capacitor element.

  (5) The arrangement position of the capacitor element can be maintained inside the case.

  (6) The capacitor element can be prevented from coming into contact with the inner wall of the case due to vibration, thereby preventing an increase in the internal resistance of the capacitor.

(7) The capacitor element is pressed with a constant pressure, so that the shape of the capacitor element can be stabilized and the internal resistance can be reduced.

It is an exploded view showing the capacitor concerning a 1st embodiment. It is a figure which shows an example of the capacitor element in a case. It is a figure which shows the other example of the capacitor element in a case.

[First Embodiment]

  FIG. 1 is an exploded view showing components of a capacitor according to the first embodiment. The capacitor 2 is an example of a capacitor according to the present disclosure, and is not limited to such a configuration.

  The capacitor 2 includes, for example, a bottomed case member 4 whose one surface is open, a capacitor element 6, and a sealing body 8 that seals an opening portion of the case member 4. In the capacitor 2, an electrolytic solution is enclosed in the case member 4 together with the capacitor element 6. The case member 4 and the sealing body 8 are examples of the outer case of the capacitor 2 and are each formed of an insulating resin.

  The case member 4 is internally partitioned by a partition wall 10, and a plurality of storage chambers 12 corresponding to the number of capacitor elements 6 to be stored are formed. The capacitor elements 6 and the electrolytic solution are stored in each storage chamber 12. The

  Capacitor element 6 may be, for example, an electric double layer capacitor, an electrolytic capacitor, or a hybrid capacitor. As an example, the capacitor element 6 may be a laminated element formed via a separator between a pair of polarizable electrode foils, or may be a laminated polarizable electrode foil and a winding element of a separator. As an example of the capacitor element 6, a columnar element having a flat element end surface is used.

  As the polarizable electrode foil, an aluminum foil is used as a collector electrode, and an activated carbon layer is formed on both surfaces of the aluminum foil to obtain a polarizable electrode foil. The separator is, for example, electrolytic paper.

  In the capacitor element 6, a band component 28 is mounted along the outer peripheral portion of the body portion around which the electrode foil and the separator are wound. The band component 28 is an example of an insulating elastic band of the present invention, is formed of an insulating resin, and surrounds the outer peripheral side along the winding direction of the capacitor element 6. That is, the capacitor element 6 is restrained in the winding center direction by the elastic force of the band component 28. The capacitor element 6 is stored in the storage chamber 12 of the case member 4 with the band component 28 mounted on the outer peripheral portion. The band component 28 can be deformed in the peripheral direction of the capacitor element 6.

  An edge of the anode-side or cathode-side electrode foil is exposed on the element end face of the capacitor element 6 and is formed flat to form an anode-side electrode portion 30 and a cathode-side electrode portion 32. A current collector plate 20 on the anode side is connected to the electrode portion 30 by the laser welding portion 11, and a current collector plate 22 on the cathode side is connected to the electrode portion 32 on the cathode side by the laser welding portion 11. The current collector plates 20, 22 are formed with bus bar connection portions 24, 26 that are partially bent and connected to the bus bar 40 embedded in the sealing body 8. In this example, the bus bar connecting portions 24, 26 are projected in an upright state toward the bus bar 40, for example, are penetrated through the through holes of the bus bar 40, and the vicinity of the contact portion between the bus bar 40 and the bus bar connecting portions 24, 26 is laser-welded. Connected.

  The sealing body 8 is an example of the sealing member of the present invention, and the storage chamber 12 is sealed by engaging the sealing surface portion with the opening of the case member 4. Further, for example, a bus bar 40 for connecting the capacitor element 6 to the sealing body 8 is integrated with the resin by insert molding. The bus bar 40 is a metal member having conductivity, and the sealing body 8 other than the bus bar 40 is formed of a thermoplastic resin such as polypropylene or polyphenylene sulfide. In insert molding, in order to increase the bonding force between the bus bar 40 and the resin, the bus bar 40 that has been subjected to surface treatment such as etching treatment, chemical treatment with a coupling agent, or laser treatment may be used. The capacitor 2 connects and functions the capacitor element 6 by connecting the bus bar 40 to the anode-side current collector plate 20 and the cathode-side current collector plate 22 respectively set.

  In addition, the sealing body 8 is formed with a vent hole 34 for discharging the gas generated in the storage chamber 12 to the outside. For example, a gas-liquid separator or the like may be installed in the vent hole 34 as a means for preventing the electrolyte in the storage chamber 12 from leaking. In addition, an electrolyte injection hole 35 is formed in the sealing body 8 according to the position of each storage chamber 12. The electrolytic solution injection hole 35 may be sealed by a sealing means (not shown) after the electrolytic solution is injected, for example, in the capacitor assembly process.

  As shown in FIG. 2, the capacitor 2 is provided with a sealing body 8 in the case member 4, so that the storage chamber 12 is blocked from the outside. The connecting portion between the case member 4 and the sealing body 8 is welded within a certain range from the exterior side, for example. Moreover, the sealing body 8 may stick an airtight resinous sheet member or the like on the exterior side to block the joint portions between the current collector plates 20 and 22 and the bus bar 40 and the air holes 34 from the outside air.

<Capacitor assembly process>

  The assembly process of the capacitor 2 includes a process of welding the sealing body 8 to the case member 4 (S1), a process of connecting the current collector plates 20 and 22 and the bus bar 40 (S2), and a process of injecting an electrolyte ( S3) is included.

  In the step (S1) of welding the sealing body 8 to the case member 4, the sealing body 8 is superimposed on the case member 4, and the contact portion between the sealing body 8 and the case member 4 is heated. By this heating, the resin at the contact portion between the sealing body 8 and the case member 4 is melted and integrated. Such heating is performed over the entire circumference of the contact portion between the sealing body 8 and the case member 4.

  In the step of connecting the current collector plates 20 and 22 and the bus bar 40 (S2), the contact portion between the bus bar 40 and the bus bar connecting portions 24 and 26 is irradiated with laser from the outside of the sealing body 8, so that the bus bar 40 and the bus bar are connected. The connecting parts 24 and 26 are welded. The connection between the bus bar 40 and the bus bar connecting portions 24 and 26 is, for example, by inserting the bus bar connecting portions 24 and 26 into the through holes formed in the bus bar 40 and at the boundary between the through holes of the bus bar 40 and the bus bar connecting portions 24 and 26. The through hole and the bus bar connecting portions 24 and 26 are welded by irradiating a laser.

  In the step of injecting the electrolytic solution (S <b> 3), the electrolytic solution is injected into the storage chamber 12 from the electrolytic solution injection hole 35 of the sealing body 8, and the capacitor element 6 stored in the storage chamber 12 is impregnated.

  FIG. 2 shows an example of the installation state of the capacitor element inside the case member.

  In the storage chamber 12 of the case member 4, the capacitor element 6 with the band component 28 attached is inserted. The capacitor element 6 is held at a predetermined height in the storage chamber 12 by integrating the bus bar 40 and the current collector plates 20 and 22.

  For example, when the band component 28 is attached to the capacitor element 6, the width in the winding direction is set to be equal to the opening width of the storage chamber 12. Thereby, the capacitor element 6 is inserted to a set depth along the inner wall and the partition wall 10 of the case member 4 forming the storage chamber 12, for example.

  Thus, in the capacitor 2, the outer peripheral surface of the band component 28 is made wider than the outer width of the capacitor element 6, so that the capacitor element 6 is inserted so as not to contact the inside of the storage chamber 12.

  When the electrolytic solution is injected into each storage chamber 12, the capacitor element 6 absorbs liquid and expands by a certain amount, so that an expansion output acts on the wall surface of the storage chamber 12 in contact with the outer peripheral portion of the capacitor element 6. . At this time, the band component 28 receives a reaction force against the expansion output from the wall surface of the storage chamber 12, and the contact strength with the wall surface is maintained. That is, the band component 28 absorbs the vibration, for example, from the outside, and elastically holds the capacitor element 6 with the wall surface inside the case.

  In addition, the capacitor element 6 is in an expanded state by absorbing the electrolytic solution. However, by setting the holding width of the band component 28, the outer diameter of the capacitor element 6 is constant due to the pressure from the band component 28. Maintained. Further, the capacitor element 6 is pressed toward the center of the element by the band component 28 against the expansion. This pressing force is a force for holding the capacitor element 6 by the band component 28.

  At this time, in the storage chamber 12, for example, a gap 50 is maintained between the body portion of the capacitor element 6 and the partition wall 10 or the wall surface of the case member 4. Further, a gap 52 having a predetermined height with respect to the bottom surface of the storage chamber 12 is maintained on the bottom surface side of the capacitor element 6.

  <Effect of the first embodiment>

  (1) Since the gaps 50 and 52 are maintained around the capacitor element 6 in the storage chamber 12, the generated gas can be efficiently guided to the sealing body 8, and the pressure inside the storage chamber 12 is reduced. It can be prevented from becoming excessive.

  (2) Since the clearances 50 and 52 are maintained, the space ratio in the storage chamber is maintained, so that an allowable space for storing generated gas is maintained, and the life characteristics are improved. That is, even when the capacitor element 6 absorbs the electrolytic solution and expands, the band component 28 provides the gap 50 between the capacitor element 6 and the storage chamber 12, so that the space ratio can be ensured and the gas can be rapidly increased. Even if this occurs, gas can be stored and the life characteristics of the product are improved.

  (3) Further, the absorption rate of the electrolytic solution of the capacitor element 6 is improved by the gaps 50 and 52. That is, the electrolytic solution is injected from the side of the sealing body 8 of the capacitor element 6. At this time, the electrolytic solution enters the bottom surface side of the capacitor element 6 through the gap 50 around the capacitor element 6. It becomes easy to be impregnated with the electrolyte uniformly.

  (4) The capacitor element 6 expanded by the band component 28 can be held in the element center direction, and the outer diameter can be held.

  (5) The capacitor element 6 is pressed by the band component 28 toward the element center. Activated carbon used for the electrode foil is a porous body and has elasticity. When pressure is applied to the activated carbon, the frequency of contact between the activated carbons increases in the porous body, and the conduction path inside the activated carbon increases, so that the electrical resistance as a whole can be reduced.

  (6) The capacitor element 6 can be firmly held in the storage chamber 12 by the band component 28, and does not cause deformation or change in the arrangement position due to external vibration.

  (7) The capacitor 2 can exhibit the set electrical characteristics without causing variations in internal resistance between the capacitor elements 6 to be connected.

  (8) Since the band component 28 is held in contact with the storage chamber 12 and the capacitor element 6 is not vibrated independently inside the case, the current collector plates 20 and 22 connected to and supported by the capacitor element 6 and the bus bar connecting portion It is possible to prevent an excessive load from being applied to 24 and 26.

  (9) By not causing the capacitor element 6 to swing inside the case, no breakage occurs between the electrode layer of the capacitor element and other components connected to the capacitor element 6.

[Second Embodiment]

  FIG. 3 shows another example of the capacitor element housed in the case. The configuration shown in FIG. 3 is an example.

  For example, as shown in FIG. 3, the band component 60 is formed along the outer periphery of the capacitor element 6, and one surface portion thereof is broken, and the broken portion can be expanded along the circumferential surface of the capacitor element 6. A widened portion 62 is formed. The expanding portion 62 changes the inner diameter of the band component 60 in accordance with, for example, the expansion of the capacitor element 6 due to the absorption of the electrolytic solution, or the pressing force acting in the center direction of the capacitor element 6 when stored in the storage chamber 12. Accordingly, the band component 60 is deformed.

  The expansion part 62 exhibits a function of adjusting the pressing force with respect to the element center of the capacitor element 6 by expanding according to the expansion of the capacitor element 6. That is, with respect to the difference in the absorption rate and expansion rate of the electrolytic solution depending on the tension and material state applied when the capacitor element 6 is wound, the pressing force on the capacitor element 6 is changed according to the expansion amount of the expansion portion 62. adjust.

  The width of the expanding portion 62 may be set according to the material of the capacitor element 6, the width of the storage chamber 12, the elastic force of the band component 60, and the like.

  <Effects of Second Embodiment>

  (1) By forming the expanded portion 62, the pressing force on the capacitor element 6 can be adjusted.

  (2) For example, when the capacitor 2 vibrates, the expansion portion 62 exhibits a spring effect due to expansion and contraction of the expansion portion 62 together with the elastic force of the band component 60, and vibration of the capacitor element 6 in the storage chamber 12. Can be prevented or attenuated.

  (3) By adjusting the opening amount of the expansion portion 62, the capacitor element 6 can be easily inserted into the storage chamber 12, and the efficiency of the capacitor assembly process can be improved.

  (4) The capacitor element 6 can be firmly held in the storage chamber 12 by the band component 60, and does not cause deformation or change in the arrangement position due to external vibration.

  (5) The capacitor 2 can adjust the pressing force by the band component 60 by the expanding portion 62 for each capacitor element 6 to be connected, and does not cause variations in internal resistance between the capacitor elements 6, and has set electrical characteristics. Can be demonstrated.

  (6) Since the gaps 50 and 52 are maintained around the capacitor element 6 in the storage chamber, the generated gas can be efficiently guided to the sealing body 8 side, and the pressure in the storage chamber becomes excessive. Can be prevented.

  (7) The fractured portion that is the expanded portion 62 connects the space above and below the band portion 60, and provides a path for gas and electrolyte to move. Therefore, the gas generated on the bottom surface side of the capacitor element 6 quickly moves above the capacitor element 6 and has a structure in which the gas does not easily accumulate in the storage chamber 12 that is discharged to the outside through the vent hole 34 formed in the sealing body 8. In addition, when the electrolytic solution is injected from above the capacitor element 6, the electrolytic solution easily moves from the fractured portion that is the spread portion 62 to the bottom surface side of the capacitor element 6. Will improve.

  [Other Embodiments]

  (a) In the above embodiment, the case where one band component 28, 60 is attached to the capacitor element 6 is shown, but the present invention is not limited to this. A plurality of band components 28 and 60 may be attached to the capacitor element 6. The number of the band components 28 and 60 may be adjusted according to, for example, the length of the long side of the capacitor element 6 and the width of the band component. Further, the number of attachments may be set according to the installation position of the band components 28 and 60 with respect to the capacitor element 6 and the overall weight of the capacitor 2.

  (b) In the above embodiment, the case where the band components 28 and 60 are mounted at positions close to the bottom surface side of the capacitor element 6 is shown, but the present invention is not limited thereto. The band components 28 and 60 may be disposed, for example, at the center portion or the upper side of the capacitor element 6.

  (c) In the above-described embodiment, the case where the expanded portion 62 of the band component 60 breaks the one surface portion along the outer circumferential direction of the capacitor element 6 is not limited to this. The band part 60 may form an opening part or a weak part in a part of plane part of the band part 60 as the expansion part 62, for example. The opening has a mesh shape or other shapes, for example, and it is sufficient that a part of the band component 60 has appropriate stretchability. The pressing force on the capacitor element 6 can be adjusted by expanding and contracting these openings or fragile portions.

 (c) The band parts 28 and 60 may have a portion facing the storage chamber 12 as an inclined surface, and the storage chamber 12 may have an inner wall as an inclined surface. That is, the band components 28 and 60 may be inclined surfaces so that the outer diameter of the band components 28 and 60 faces the storage chamber 12, for example, from the upper side of the capacitor element 6 toward the bottom surface. On the other hand, the inner wall of the storage chamber 12 is formed such that the cross-sectional area of the storage chamber 12 gradually increases toward the opening side of the storage chamber 12, that is, the side where the sealing body 8 of the storage chamber 12 is disposed. The band members 28, 60 press the capacitor element 2 toward the center as the capacitor element 6 fitted with the band member 28 is inserted into the storage chamber 12 due to the inclined surface of the inner wall of the storage chamber 12. The capacitor element 6 is gradually contracted toward the outer peripheral surface of the capacitor element 6, and the capacitor element 6 is tightened. Then, the inclined surfaces come into contact with each other, and the band components 28 and 60 are held on the inner wall surface of the storage chamber 12 by friction between them, and a gap is formed between the storage chamber 12 and the capacitor element 6. With such a structure, the fixing force to the capacitor 6 is further improved.

  (d) In the above embodiment, a flat capacitor element is used, but a capacitor element of another shape such as a cylindrical capacitor element or a hexahedral capacitor element may be used.

  (e) In the above embodiment, the electric double layer capacitor is used as the capacitor element. However, the present invention is not limited to this, and the same structure and method can be applied to an electrolytic capacitor and a hybrid capacitor in the same manner, and the same effect can be obtained. It is done.

As described above, the most preferable embodiment of the capacitor has been described. However, the present invention is not limited to the above description, and the gist of the invention described in the claims or disclosed in the specification. It goes without saying that various modifications and changes can be made by those skilled in the art based on the above, and such modifications and changes are included in the scope of the present invention.

According to the present invention, it is possible to prevent or suppress the vibration of the capacitor element in the storage chamber of the case member, to prevent a decrease in internal resistance and a decrease in the supporting strength of the capacitor element, and to improve reliability by ensuring the stability of the capacitor performance. It is useful because it can exert its properties.

2 Capacitor 4 Case member 6 Capacitor element 8 Sealing body 10 Partition wall 11 Laser welded portion 12 Storage chamber 14 Sealing portion 20, 22 Current collector plate 24, 26 Connection terminal 28, 60 Band component 30, 32 Electrode portion 35 Electrolyte injection Hole 40 Bus bar 50, 52 Clearance 62 Widened part

Claims (3)

A case member in which a capacitor element is stored in each of two or more storage chambers partitioned by a partition wall;
A sealing member for sealing the storage chamber;
An insulating elastic band that is attached to the outer periphery of the capacitor element and is deformable;
With
The insulating elastic band attached to the capacitor element causes the capacitor element swollen by impregnation with the electrolyte to be pressed in the center direction to provide a space between the capacitor element and the inner wall of the storage chamber. Features a capacitor.   2. The capacitor according to claim 1, wherein the insulating elastic band includes an expanding portion that expands according to expansion of the capacitor element and changes an inner diameter. 3. The inner wall has an inclination so that the cross-sectional area of the storage chamber gradually decreases toward the sealing member,
A portion of the insulating elastic band facing the storage chamber has an inclination so that the outer diameter gradually decreases toward the sealing member,
2. The capacitor element is pressed in the center direction by inserting the insulating elastic band into the storage chamber while the inclination of the insulating elastic band is in contact with the inner wall of the storage chamber. 2. The capacitor according to 2.

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