JP2008204982A - Capacitor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a capacitor unit, and to reduce its weight by controlling the voltage across each capacitor, using a single circuit board. <P>SOLUTION: The capacitor unit comprises a plurality of capacitors 5 that have a cylindrical case 5a, having an opening on the upper surface and a lid 5b for sealing the opening and are arranged side by side, while a first end face electrode 6 is formed on the lid 5b and a second end face electrode 7 is formed on the lower end face of the cylindrical case 5a; a first bus bar 12 and a second bus bar 13 connecting the first end face electrode 6 and the second end face electrode 7 in the adjacent capacitors 5; and a circuit board arranged at the upper portion of the capacitor 5. Since the first bus bar 12 is connected to the circuit board and the cylindrical case 5a is electrically connected to the circuit board via a monitor terminal section 17 provided at the upper portion of the cylindrical case 5a, the voltage across each capacitor 5 can be measured by using only a single circuit board, and the capacitor unit can be miniaturized and reduced in weight. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a capacitor unit that stores electric power with a capacitor and is used as an auxiliary power source or the like.

  In recent years, vehicles equipped with a hybrid system and an idling stop system have been developed from the viewpoint of environmental protection, but these systems regenerate the braking energy of the vehicle as electric energy or drive a high output motor. In order to do so, it is necessary to have a configuration in which electrical energy is temporarily stored in the storage element.

  As such a configuration, for example, Patent Document 1 describes a battery unit that stores electrical energy in a battery and backs up an information processing apparatus.

  As shown in FIG. 9, the battery unit includes a plurality of batteries 1 having electrodes on both end faces, and a bus bar 2 made of a plate-like metal that electrically connects the plurality of batteries 1.

  The bus bars 2 are alternately arranged at both ends of the plurality of batteries 1, and the plurality of batteries 1 connected by the bus bar 2 are connected in a plurality of stages and arranged in the horizontal direction. Further, an insulating sheet 3 is provided between the stages to prevent a short circuit.

With the above configuration, this battery unit normally stores electrical energy in the battery, and supplies power to the information processing apparatus when the power supply source shows an abnormality due to a power failure or the like.
JP 2003-309935 A

  Certainly, the battery unit can back up necessary power to the information processing apparatus or the like in the event of a power failure or the like to prevent the system from going down. However, when this battery unit is used in a vehicle, the following problems occur.

  That is, in a vehicle regenerative system, it is necessary to store suddenly changing braking energy as electrical energy in a power storage element, and in the case of motor drive assistance, it is necessary to supply electrical energy only to accelerate the vehicle. However, the battery 1 used as the storage element of the conventional battery unit is inferior in rapid charge / discharge characteristics.

  On the other hand, instead of the battery 1, a configuration using a capacitor capable of rapid charging / discharging may be used. However, when the voltage at both ends of the capacitor becomes higher than a predetermined value, deterioration of characteristics may be promoted. . Therefore, when using capacitors, it is necessary to provide a voltage balance circuit for measuring and controlling the voltage across each capacitor. When this is applied to the configuration of a conventional battery unit, the bus bars 2 are alternately provided at the upper and lower end portions 4 of the capacitor. Therefore, a circuit board having a voltage balance circuit must be provided at the upper and lower end portions 4 of the capacitor. As a result, there is a problem that the capacitor unit becomes larger and heavier.

  In view of the above, an object of the present invention is to reduce the size and weight of a capacitor unit.

  In order to achieve this object, the present invention has a cylindrical case having an opening on the upper surface and a lid for sealing the opening, and the first end face electrode is formed on the lid and the cylinder is formed. A second end face electrode is formed on the lower end face of the cylindrical case, and a plurality of capacitors arranged in parallel with each other and the first end face electrodes of adjacent capacitors among the plurality of capacitors are electrically connected to each other. A first bus bar, a second bus bar that electrically connects the second end face electrodes of adjacent capacitors among the plurality of capacitors, and a circuit board disposed on the plurality of capacitors. And electrically connecting the first bus bar and the circuit board, and electrically connecting the cylindrical case and the circuit board via a monitor terminal provided on the upper part of the cylindrical case. Let It was formed.

  With the above-described configuration, the present invention enables measurement and control of the voltage across each capacitor with a circuit board disposed on the top of the capacitor. This is because the bus bar provided on the capacitor and the circuit board are electrically connected and the cylindrical case and the circuit board are electrically connected. Here, the connection between the cylindrical case and the circuit board only requires a side conductive part integrated with the monitor terminal at the upper part of the cylindrical case, and is further required for measurement and control of the voltage across the capacitor. Since only one circuit board is used, the configuration of the present invention can reduce the size and weight of the capacitor unit.

(Embodiment 1)
Hereinafter, the configuration of the capacitor unit according to the first embodiment of the present invention will be described with reference to the drawings.

  In FIG. 1, the plurality of capacitors 5 includes a bottomed cylindrical case 5 a having a diameter of 3 cm having an opening on the upper surface, and a lid 5 b that seals the opening. The plurality of capacitors 5 are connected to the internal electrode of the capacitor 5 to form a first end face electrode 6 in the lid 5b, and have a polarity different from that of the first end face electrode 6 on the lower end face of the cylindrical case 5a. This is an electric double layer capacitor forming the second end face electrode 7, thereby storing electric power. The cylindrical case 5a and the lid 5b of the capacitor 5 are both made of aluminum. Further, since the capacitor 5 is electrically connected from the lower end surface of the cylindrical case 5a forming the second end surface electrode 7 to the side surface portion 8 of the cylindrical case 5a, the entire side surface portion 8 is the second end surface electrode. 7 and approximately the same voltage. In the first embodiment, since the capacitors 5 are connected in series, the polarities of the first end face electrodes 6 of the adjacent capacitors 5 are different from each other. Similarly to the first end face electrode 6, the second end face electrode 7 and the side face portion 8 have different polarities from the second end face electrode 7 and the side face portion 8 of the adjacent capacitor 5. Further, the semicircular protruding portion 9 formed integrally with the first end face electrode 6 is configured to have a height higher than that of the end face surrounding portion 10. An insulating member (not shown) is disposed around the lid 5b to prevent a short circuit between the first end face electrode 6 having a different polarity and the side face 8 of the cylindrical case 5a. is doing. Note that a pressure regulating valve 11 is provided on the surface of the lid 5b portion of the capacitor 5. The pressure regulating valve 11 is discharged from a discharge hole 11a provided on the outer surface of the pressure regulating valve 11 when the electrolytic solution in the capacitor 5 is vaporized. The vaporized electrolyte is discharged to prevent the pressure inside the capacitor 5 from rising. Since the pressure regulating valve 11 is provided in the lid 5b portion located on the upper portion of the capacitor 5, the possibility of the electrolyte solution leaking from the discharge hole 11a is reduced, and high reliability is obtained.

  The first bus bar 12 is disposed on the capacitor 5. The first bus bar 12 is connected to the protruding portion 9 of the capacitor 5 to electrically connect the adjacent capacitors 5 to each other.

  The second bus bar 13 is connected to the second end face electrode 7 to electrically connect the adjacent capacitors 5 similarly to the first bus bar 12. A plurality of capacitors 5 are connected in series by alternately arranging the first bus bar 12 and the second bus bar 13 at both ends of the capacitor 5.

  The L-shaped bus bar 14 is connected to the protruding portion 9 of the capacitor 5 located at the end, and an L-shaped bus bar screw hole 14a is provided for electrical connection with external wiring. Connection with external wiring will be described later.

  The first bus bar 12, the second bus bar 13, and the L-shaped bus bar 14 improve the weldability of the capacitor 5 with the first end face electrode 6 and the second end face electrode 7. The case 5a and the lid 5b are made of the same aluminum and can be obtained by press-molding an aluminum plate. In the first embodiment, the first bus bar 12, the second bus bar 13, and the L-shaped bus bar 14 are made of aluminum. However, as long as the case 5a and the lid 5b of the capacitor 5 are the same, a metal other than aluminum may be used. .

  The bus bar conductive portion 15 is provided in a protruding shape on the top of the first bus bar 12. The bus bar conductive portion 15 is tin-plated so as to be connected to a circuit board (32 in FIG. 2) to be described later by soldering. By connecting the bus bar conductive portion 15 to the circuit board 32, the first bus bar 12 and The voltage at the L-shaped bus bar 14 is detected.

  The monitor terminal portion 17 is made of aluminum, is integrated with the side surface conductive portion 16, and is provided so as to protrude upward. The side surface conductive portion 16 is connected to the side surface portion 8 by laser welding a portion indicated by a cross in FIG. Further, since the side surface portion 8 is electrically connected to the second end face electrode 7, the circuit board 32 detects the voltage at the second end face electrode 7 by connecting the monitor terminal portion 17 to the circuit board 32. it can. The monitor terminal portion 17 is tin-plated to be soldered to the circuit board 32 in the same manner as the bus bar conductive portion 15.

  The first fixing case 18 is made of resin, and the upper part of the capacitor 5 is inserted and fixed. The first fixed case 18 is provided with a first bus bar opening 19 and an L-shaped bus bar opening 20 for connecting the first bus bar 12 and the L-shaped bus bar 14 and the protruding portion 9. . The first fixing case 18 is provided with a monitor terminal portion hole 21, and the monitor terminal portion 17 is fixed by being inserted into the monitor terminal portion hole 21. In FIG. 1, an insert nut 22 is embedded in the left end portion of the first fixed case 18, and the L-shaped bus bar 14 and the external bus bar (30 in FIG. 2 described later) are electrically connected by the insert nut 22. Mechanically connected. Further, an upper fixing screw hole 23 is provided near the L-shaped bus bar opening 20. By fixing the fixing rod 24 at the position of the upper fixing screw hole 23 and tightening the upper fixing screw 25 from above, the fixing rod 24 and the first fixing case 18 are fixed. At this time, the upper fixing screw 25 is a countersunk screw so that the L-shaped bus bar 14 and the upper fixing screw 25 do not contact each other. Although not shown, an upper fixing screw hole for attaching the fixing rod 24 is also provided at the right end portion of the first fixing case 18.

  Similarly to the first fixed case 18, the second fixed case 26 is formed of resin. A circular holding hole 27 is provided in the upper part of the second fixing case 26, and the lower part of the capacitor 5 is inserted and fixed in the holding hole 26. Further, a lower fixing screw hole 28 is provided at the left end portion of the second fixing case 26, and a lower fixing screw 29 made of a countersunk screw is fastened to the fixing rod 24 arranged at the position of the lower fixing screw hole 28. As a result, the fixing rod 24 and the second fixing case 26 are fixed. Although not shown, a lower fixing screw hole for attaching the fixing rod 24 is also provided at the right end portion of the second fixing case 26.

  2 and 3 show the assembled state of the above components. The first fixed case 18 and the second fixed case 26 are connected by a fixed rod 24, and the capacitor 5 is firmly fixed by being sandwiched between the first fixed case 18 and the second fixed case 26. .

  The first bus bar 12 and the L-shaped bus bar 14 are covered with the protruding portion 9 provided on the upper end surface of the capacitor 5. Here, the first bus bar 12 and the L-shaped bus bar 14 are connected to the projecting portion 9 by laser welding the portion indicated by x in FIG. And mechanical connection is obtained. In addition, although the example which welded many points | pieces in the spot form was shown in FIG. 2, this may be weld-connected linearly, shifting a welding position sequentially. In this case, the connection reliability is improved as compared with the case of spot welding. Although not shown, the second bus bar 13 is also welded to the lower end surface of the capacitor 5 in the same manner.

  The capacitor unit thus formed is fixed by tightening an external bus bar screw hole 30a provided in the external bus bar 30 to the insert nut 22 with a screw 31 for wiring with the outside. At this time, since the L-shaped bus bar 14 is fixed, the external bus bar 30 and the L-shaped bus bar 14 are electrically connected. The external bus bar 30 has a bent portion 30b. Thereby, the bending part 30b absorbs the stress by vibration or heat, and the possibility that the external bus bar 30 is damaged can be reduced.

  Here, since the monitor terminal portion 17 is inserted into the monitor terminal portion hole 21, the monitor terminal portion 17 protrudes from the upper surface of the first fixed case 18. In this state, the monitor terminal portion 17 and the bus bar conductive portion 15 are inserted into the bus bar connection hole 33 and the monitor terminal portion connection hole 34 provided in the circuit board 32 and soldered, whereby the first bus bar 12 and the L-shaped The bus bar 14 and the side conductive part 16 are electrically connected to the circuit board 32.

  The circuit board 32 has a voltage balance circuit (not shown) for measuring and controlling the voltage of each capacitor 5.

  By assembling so far, the capacitor unit is completed as shown in FIG.

  Next, FIG. 4 shows a cross-sectional view of a rectangular portion indicated by a dotted line in FIG.

  As described above, since the protruding portion 9 is provided higher than the end surface peripheral portion 10, the first bus bar 12 comes into contact with the end surface peripheral portion 10 and is short-circuited as is apparent from FIG. 4. There is no.

  Further, the pressure regulating valve 11 is covered so as to face a part of the cover portion 18a of the first fixed case 18, and is separated from the circuit board 32 and the first bus bar 12 by the cover portion 18a. Further, the pressure regulating valve 11 is configured to have a height lower than that of the end surface peripheral portion 10, and there is a gap between the pressure regulating valve 11 and the first fixed case 18 disposed in the upper part thereof. Therefore, since the discharge hole 11a is not blocked, the electrolyte solution vaporized from the discharge hole 11a is normally discharged.

  Next, the operation of the capacitor unit in the first embodiment of the present invention will be described below.

  As described above, if the voltage at both ends of the capacitor 5 becomes too high, the deterioration of the characteristics may proceed. To prevent this deterioration of the characteristics, the first end face electrode 6 and the second end face electrode 7 of each capacitor 5 are used. Must be measured sequentially to control the voltage across capacitor 5.

  Therefore, in the first embodiment, the first bus bar 12 and the circuit board 32 are connected via the bus bar conductive part 15 of FIGS. 1 to 4, and the side face part 8 and the circuit board 32 are connected via the monitor terminal part 17. Is connected. That is, since the side surface portion 8 is electrically connected to the second end surface electrode 7 and has substantially the same voltage, if the side surface portion 8 and the circuit board 32 are electrically connected, the second end surface is formed on the circuit board 32. It is possible to measure the voltage at the electrode 7.

  As a result, the voltage at the first end face electrode 6 and the second end face electrode 7 can be measured on the circuit board 32, and the voltage across the capacitor 5 can be controlled.

  Next, the effect in Embodiment 1 of this invention is demonstrated below.

  First, in the first embodiment, the capacitor unit can be reduced in size and weight.

  This is because the voltage at the first end face electrode 6 and the second end face electrode 7 can be measured and controlled by the single circuit board 32 by the above-described configuration. Further, the electrical connection between the side surface portion 8 and the circuit board 32 is possible only by the side surface conductive portion 16 integrated with the monitor terminal portion 17 provided on the upper portion of the side surface portion 8. Therefore, the capacitor unit can be reduced in size and weight.

  Further, in the first embodiment, the side surface conductive portion 16 is welded to the side surface portion 8 of the capacitor 5. Thereby, the side conductive part 16 and the side part 8 are firmly connected, and the possibility of breakage in the connection part can be reduced. In particular, when the capacitor unit is mounted on a vehicle, it is considered that the vibration of the vehicle vibrates in the capacitor unit. Therefore, the capacitor unit with this configuration is useful.

  The pressure regulating valve 11 is configured to be separated from the circuit board 32 and the first bus bar 12 by facing the cover portion 18a. Thereby, even if the electrolytic solution evaporated from the discharge hole 11a is discharged, it does not adhere to the circuit board 32 and the first bus bar 12, and the possibility of corrosion can be reduced. Therefore, high reliability of the capacitor unit can be obtained.

  The capacitor 5 may be arranged in a horizontally placed state, and the pressure regulating valve 11 may be arranged above the center of the lid 5b of the capacitor 5. Thus, even when the capacitor units are arranged in the horizontal direction, by using the configuration of the present invention, the voltage of each capacitor 5 can be obtained by the circuit board 32 provided only on the first end face electrode 6 side of the capacitor 5. It is possible to measure, and the capacitor unit can be reduced in size and weight. Furthermore, since the pressure regulating valve 11 is disposed above the center of the lid 5b of the capacitor 5, the possibility of the electrolyte leaking from the discharge hole 11a can be reduced. In addition, since the capacitor unit mounted on the vehicle is often mounted under the floor and requires a low profile, if the capacitor unit 5 is placed in a parallel horizontal state as described above and the overall height is lowered, It is suitable as a capacitor unit.

  Further, since the side surface portion 8 of the capacitor 5 has an electrode having the same polarity as the second end surface electrode 7, the first end surface electrodes 6 of the adjacent capacitors 5 are electrically connected to each other and the side surface portions 8 are electrically connected to each other. The capacitors 5 may be connected in series. The configuration of the present invention can also be applied to this configuration.

  Although the cylindrical capacitor 5 is employed in the first embodiment, the present invention is not limited thereto, and a prismatic or other shape capacitor may be employed.

(Embodiment 2)
Hereinafter, the configuration of the capacitor unit according to the second embodiment of the present invention will be described with reference to the drawings.

  The difference between the second embodiment and the first embodiment is that the side surface conductive portion 16 is fixed to the first fixed case 18 as shown in FIG. The side conductive portion 16 is integrally formed with the first fixing case 18 by insert molding and is securely fixed. Although not shown, the side conductive portion 16 is partially exposed inside the first fixed case 18 to be connected to the side portion 8, and is further made of aluminum like the case 5 a and the lid 5 b of the capacitor 5. Is formed. The monitor terminal portion 17 protrudes upward from the first fixed case 18 and is tin-plated in order to connect to the circuit board. Other components are the same as those in the first embodiment.

  When these are assembled, the state shown in FIGS. 6 and 7 is obtained. The side surface conductive portion 16 is connected to the side surface portion 8 by laser welding at the position of the x mark. The monitor terminal portion 17 and the bus bar conductive portion 15 are inserted into the monitor terminal portion connection hole 34 and the bus bar connection hole 33, respectively, and the first end surface electrode 6 and the side surface portion 8 are electrically connected to the circuit board 32.

  When the monitor terminal portion 17 and the bus bar conductive portion 15 are soldered to the terminal portion connection hole 34 and the monitor bus bar connection hole 33, respectively, the capacitor unit shown in FIG. 7 is completed.

  Next, FIG. 8 shows a cross-sectional view of a dotted-line square portion shown in FIG.

  As shown in FIG. 8, the left and right end portions 35 of the side surface conductive portion 16 are bent in the opposite direction to the contact surface 36 with the side surface portion 8. Further, the contact surface 36 of the side surface conductive portion 16 has an arc shape because it contacts the side surface portion 8. In the second embodiment, the side surface conductive portion 16 and the side surface portion 8 are connected by laser welding. However, a fine protruding rib is provided on the abutting surface 36 without welding, and the rib is crushed. By inserting the capacitor 5 into the first fixed case 18, the side conductive part 16 and the side part 8 of the capacitor 5 may be electrically connected. Even in this configuration, the connection between the side surface conductive portion 16 and the side surface portion 8 can be secured.

  Next, the effect in Embodiment 2 of this invention is demonstrated below.

  According to the second embodiment, the side surface portion 8 and the first end surface electrode 6 are electrically connected to the circuit board 32 as in the first embodiment as shown in FIGS. The voltage of each capacitor 5 can be controlled only by the circuit board 32 arranged on the upper part. As a result, the capacitor unit can be reduced in size and weight.

  The side conductive portion 16 is integrally formed with the first fixing case 18 by insert molding, and is firmly fixed. As a result, it is possible to reduce the possibility that the connection between the side conductive portion 16 and the first fixed case 18 is damaged when vibration is transmitted to the capacitor unit when the capacitor unit is mounted on the vehicle.

  Further, the left and right end portions 35 of the buried portion in the first fixed case 18 of the side surface conductive portion 16 are bent. As a result, the contact area between the side conductive portion 16 and the first fixed case 18 is increased as compared with the case where the side conductive portion 16 has a flat configuration, and the connection between the side conductive portion 16 and the first fixed case 18 is increased. More secure. The left and right end portions 35 may be curved. Also in this configuration, the contact area with the first fixed case 18 increases, and the same effect can be obtained.

  The capacitor unit according to the present invention can measure the voltage across each capacitor on a single circuit board by providing a side conductive part integrated with the monitor terminal part on the side of the capacitor. This is particularly useful as a capacitor unit as an auxiliary power source for vehicles.

1 is an exploded perspective view of a capacitor unit according to Embodiment 1 of the present invention. 1 is a partially assembled perspective view of a capacitor unit according to Embodiment 1 of the present invention. The completed perspective view of the capacitor unit in Embodiment 1 of this invention Partial sectional view of the capacitor unit according to the first embodiment of the present invention. The exploded perspective view of the capacitor unit in Embodiment 2 of the present invention. The partial assembly perspective view of the capacitor unit in Embodiment 2 of this invention The completed perspective view of the capacitor unit in Embodiment 2 of this invention Partial sectional view of the capacitor unit according to the second embodiment of the present invention. A perspective view of a conventional battery unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Capacitor 5a Case 5b Cover 6 1st end surface electrode 7 2nd end surface electrode 8 Side surface part 9 Protrusion part 10 End surface surrounding part 11 Pressure regulation valve 11a Ejection hole 12 1st bus bar 13 2nd bus bar 14 L-shaped bus bar 14a L-shaped bus bar screw hole 15 Bus bar conductive part 16 Side conductive part 17 Monitor terminal part 18 First fixing case 19 First bus bar opening part 20 L-shaped bus bar opening part 21 Monitor terminal part hole 22 Insert nut 23 Upper fixing screw hole 24 fixing rod 25 upper fixing screw 26 second fixing case 27 holding hole 28 lower fixing screw hole 29 lower fixing screw 30 external bus bar 30a external bus bar screw hole 30b bent part 31 screw 32 circuit board 33 bus bar connecting hole 34 monitor terminal part connecting hole 35 Left and right ends 36 Contact surface

Claims (7)

A cylindrical case having an opening on the upper surface and a lid for sealing the opening. A first end surface electrode is formed on the lid, and a second end surface electrode is formed on the lower end surface of the cylindrical case. A plurality of capacitors arranged in parallel with each other;
A first bus bar that electrically connects the first end face electrodes of adjacent capacitors among the plurality of capacitors;
A second bus bar for electrically connecting the second end face electrodes of adjacent capacitors among the plurality of capacitors;
A circuit board disposed on top of the plurality of capacitors,
A capacitor unit in which the first bus bar and the circuit board are electrically connected, and the cylindrical case and the circuit board are electrically connected via a monitor terminal provided on an upper portion of the cylindrical case. . The capacitor unit according to claim 1, wherein the monitor terminal portion is integrated with a side surface conductive portion, and the side surface conductive portion is welded to an upper side surface of the cylindrical case. A first fixed case and a second fixed case for holding the capacitors in parallel with each other by inserting an upper part and a lower part of the capacitor, respectively;
A pressure regulating valve provided on the lid of the capacitor;
3. The capacitor unit according to claim 1, wherein the first fixing case includes a cover portion that separates the pressure regulating valve from the first bus bar and the circuit board. 4. The capacitor unit according to claim 3, wherein the plurality of capacitors are arranged in a horizontally placed state parallel to each other, and the pressure regulating valve is arranged to be above the center of the lid. A first fixed case and a second fixed case for holding the capacitors in parallel with each other by inserting an upper part and a lower part of the capacitor, respectively;
A side conductive portion integrated with the monitor terminal portion;
The capacitor unit according to claim 1, wherein the side surface conductive portion is fixed to the first fixed case. The capacitor unit according to claim 5, wherein the side surface conductive portion is integrally formed with the first fixed case by insert molding. The left and right end portions of the side conductive portion embedded in the first fixed case or the second fixed case are bent or curved in the opposite direction with respect to the contact surface with the side surface of the cylindrical case. The capacitor unit according to claim 5 or 6.

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