JP2008204984A - Capacitor unit and manufacturing method therefor - 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 9 that have an end face electrode 11 on one end face and a side electrode 13 having polarity different from that of the end face electrode 11 on the side, and are arranged side by side; a bus bar 21 that is connected to an end face electrode 11 in the capacitor 9 and is connected in part to the side electrode 13 in the adjacent capacitor 9; and a circuit board arranged at one end face side or the other end face side of the plurality of capacitors 9. Since the bus bar 21 is connected to the circuit board electrically via a conductive section 29 provided toward the circuit board 53 from the bus bar 21, the voltage across each capacitor 9 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 and the like, and a manufacturing method thereof.

  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, a battery unit that stores electrical energy in a battery and backs up an information processing apparatus is described in Patent Document 1 below.

  As shown in FIG. 10, this battery unit was provided with a plurality of batteries 1 having electrodes on both end faces, and a bus bar 3 made of a plate-like metal for electrically connecting the plurality of batteries 1.

  The bus bars 3 are alternately arranged at both ends of the plurality of batteries 1, and the plurality of batteries 1 connected by the bus bar 3 are connected in a plurality of stages and arranged in the horizontal direction. Further, an insulating sheet 5 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 3 are alternately provided at the upper and lower end portions 7 of the capacitor. Therefore, it is necessary to provide a circuit board having a voltage balance circuit at the upper and lower end portions 7 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 an end face electrode on one end face and a side face electrode having a polarity different from that of the end face electrode from the other end face to the side face. A capacitor, a bus bar connected to the end face electrode of the capacitor and partly connected to the side face electrode of the adjacent capacitor, and the one end face side or the other end face side of the plurality of capacitors. The circuit board is arranged, and the bus bar and the circuit board are electrically connected via a conductive portion provided from the bus bar toward the circuit board.

  The present invention also includes a plurality of capacitors arranged side by side having an end face electrode on one end face and a side face electrode having a polarity different from that of the end face electrode from the other end face to the side face. A bus bar connected to the end face electrode and partially connected to the side electrode of the adjacent capacitor; a circuit board disposed on the one end face side of the plurality of capacitors; and the circuit from the bus bar The capacitors are formed by inserting a conductive portion provided toward the substrate and electrically connecting the bus bar and the circuit board, the one end surface having the end surface electrode of the capacitor, and the other end surface, respectively. The first fixed case and the second fixed case that hold the two parallel to each other, and the connection portion of the bus bar with the side electrode Is inserted into the side electrode, and the capacitor is inserted into the first fixed case and the second fixed case, and the bus bar and the end surface electrode are welded to each other. The capacitor unit was manufactured by welding and joining.

  The present invention also includes a plurality of capacitors arranged side by side having an end face electrode on one end face and a side face electrode having a polarity different from that of the end face electrode from the other end face to the side face. A bus bar connected to the end face electrode and partially connected to the side electrode of the adjacent capacitor; a circuit board disposed on the one end face side of the plurality of capacitors; and the circuit from the bus bar The capacitors are formed by inserting a conductive portion provided toward the substrate and electrically connecting the bus bar and the circuit board, the one end surface having the end surface electrode of the capacitor, and the other end surface, respectively. Are provided on the upper surface of the first fixed case and the first fixed case, and the bus bar. A bus bar hole for inserting a connection portion with a surface electrode; and a through hole provided at a position facing the connection portion on the side surface of the first fixed case when the connection portion is inserted into the bus bar hole. The connection portion is inserted into the bus bar hole in a state where the capacitor is inserted and held in the first fixed case and the second fixed case, and the bus bar and the end face electrode are welded and joined. The capacitor unit is manufactured by welding the connection portion and the side electrode through the through hole.

  With the above configuration, the present invention can measure and control the voltage across each capacitor by a control circuit formed on a circuit board disposed on one end face side of the capacitor. This is because the bus bar having a shape for connecting the end face electrode and the side face electrode of adjacent capacitors is arranged, thereby enabling connection between the conductive portion provided on the bus bar and the circuit board. With this configuration, it is possible to measure and control the voltage across each capacitor with a single circuit board, and to reduce the size and weight of the capacitor unit.

  Further, according to the present invention, the circuit board can be made into one piece by the above-described configuration, so that the capacitor unit can be reduced in size and weight. By welding and connecting the side electrode and the side electrode, even if there is a dimensional error in the height direction of the capacitor or the end electrode, the length of the side electrode when the bus bar and end electrode are welded Since it can move along the direction, stress due to the dimensional error is not applied to the welded portion and the bus bar after the welding joint, and the reliability can be improved.

  Further, according to the present invention, the circuit board can be made into one piece by the above configuration, so that the capacitor unit can be reduced in size and weight, and the connection portion with the side electrode of the bus bar is first inserted into the bus bar hole. After welding the bus bar and the end face electrode to each other, and manufacturing by welding the connecting portion and the side electrode through the through hole, the above-described high reliability can be obtained, and the connecting portion is simply inserted into the bus bar hole. Thus, the positioning of the bus bar can be facilitated, so that the assembly workability can be improved.

(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.

  As shown in FIG. 1, the plurality of capacitors 9 installed vertically in parallel with each other are cylindrical electric double layer capacitors having a diameter of 3 cm, and electricity is stored by the plurality of capacitors 9. Further, each capacitor 9 is internally connected so that the upper end face forms a positive end face electrode 11 and the side face forms a negative side face electrode 13 from the cylindrical bottom face. Therefore, the capacitor 9 is caulked so that an insulating member (not shown) is disposed between the end face electrode 11 and the side face electrode 13 in order to insulate the end face electrode 11 and the side face electrode 13. Further, the end face electrode 11 is provided with a pressure regulating valve 15 and a semicircular protrusion 19 in which a part of the end face electrode 11 protrudes from the end face peripheral portion 17. The pressure regulating valve 15 discharges the vaporized electrolytic solution from the discharge hole 15a provided on the outer surface of the pressure regulating valve 15 when the electrolytic solution inside the capacitor 9 is vaporized and the internal pressure of the capacitor 9 rises above a predetermined pressure. . This prevents the internal pressure of the capacitor 9 from increasing beyond a predetermined pressure. Since the pressure regulating valve 15 is disposed on the upper end face of the capacitor 9, the possibility that the electrolyte in the capacitor 9 leaks to the outside is reduced. The end face electrode 11 and the side face electrode 13 of the capacitor 9 used in the first embodiment are formed of aluminum.

  As shown in FIG. 1, the bus bar 21 has a circumferential portion 21 a connected to the side electrode 13 of the capacitor 9, and further connects a flat portion 21 b and a protruding portion 19 that protrudes a part of the end surface electrode 11. Thus, the end face electrode 11 and the side face electrode 13 of the capacitor 9 are electrically connected.

  Here, the welding of the bus bar 21 and the capacitor 9 will be described. The bus bar 21 has a circumferential portion 21 a that is fitted into the side electrode 13 and a flat portion 21 b that is in contact with the protruding portion 19. Accordingly, the circumferential portion 21 a is an electrical connection portion between the bus bar 21 and the side electrode 13. Hereinafter, this connection portion is referred to as a circumferential portion 21a. The reason why the connecting portion has a circumferential shape is that capacitor 9 of the first embodiment has a cylindrical shape. As shown in FIG. 2A, the circumferential portion 21a is fitted to the side electrode 13 from the direction of the arrow to a predetermined position. Here, the predetermined position means that when the plurality of capacitors 9 are arranged side by side as shown in FIG. 1, the flat portion 21 b of the bus bar 21 just comes into contact with the protruding portion 19 of the adjacent capacitor 9. It is the position. Next, the portions marked with x shown in FIG. 2B are welded in a spot shape. In the first embodiment, multiple points are welded in a spot shape, but the welding positions may be sequentially shifted and welded in a linear shape. When it is welded in a linear form, it can be welded more firmly than when it is welded in a spot form. In the first embodiment, the laser welding machine is fixed and the capacitor 9 main body is rotated to sequentially shift the welding points and perform laser welding. This is because the laser can be focused more easily and can be accurately welded than when welding by rotating a laser welder around the capacitor 9. In addition, as shown in FIG. 3, it is good also as a structure which provides the bending part 21c between the contact parts with the side surface electrode 13 in the vicinity of the contact part with the end surface electrode 11. FIG. It is easier to process the bent portion 21c if it is provided on the flat portion 21b.

  Further, the end bus bar 23 shown on the front side in FIG. 1 is connected to the side electrode 13 of the capacitor 9 located on the front side, and is further provided with a screw hole 25 for electrical connection with external wiring. . The welding method of the end bus bar 23 and the capacitor 9 is the same as that of the bus bar 21. However, the end bus bar 23 is fitted into the capacitor 9 and welded to a position where the screw hole 25 matches the insert nut 37 when the capacitor 9 is inserted into a first fixing case 33 described later.

  The L-shaped bus bar 27 located at the innermost position in FIG. 1 is connected to the protruding portion 19 of the capacitor 9. Although not shown, the L-shaped bus bar 27 is provided with screw holes for connection to external wiring, as with the end bus bar 23.

  In the first embodiment, the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 improve the weldability of the end surface electrode 11 and the side electrode 13 of the capacitor 9. Although it was made of the same aluminum as the electrode 13, it may be other than aluminum as long as it is the same metal. The bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 are obtained by press-molding an aluminum plate.

  The conductive portion 29 is integrally formed in a protruding shape on top of the bus bar 21, end bus bar 23, and L-shaped bus bar 27. Further, a protruding terminal portion 31 is integrally formed on the upper portion of the conductive portion 29, and this terminal portion 31 is tin-plated to be connected to a circuit board 53 of FIG. 4 described later by soldering. By connecting the terminal portion 31 and the circuit board 53, the circuit board 53 detects voltages at the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27.

  The first fixing case 33 is made of resin, and the upper part of the capacitor 9 is inserted and fixed. The conductive portion 29 and a part of the bus bar 21 are exposed from the bus bar opening 35 provided in the first fixed case 33. The L-shaped bus bar 27 is disposed on the upper portion of the first fixed case 33 and is connected to the protruding portion 19 of FIG. 1 exposed from the end opening 35a as described above. An insert nut 37 is embedded in the left end portion of the first fixed case 33, and the end bus bar 23 and an external bus bar 55 of FIG. 4 to be described later are electrically and mechanically connected by the insert nut 37. The first fixing case 33 is provided with an upper fixing screw hole 39. The fixing rod 41 and the first fixing case 33 are fixed by disposing the fixing rod 41 at the position of the upper fixing screw hole 39 and tightening the upper fixing screw 43 from above.

  Similarly to the first fixed case 33, the second fixed case 45 is formed of resin. The second fixing case 45 is provided with a holding hole 47, and the lower part of the capacitor 9 is inserted into the holding hole 47 and fixed. At this time, since the bus bar 21 has to be put on the end face electrode 11 of the adjacent capacitor 9, the capacitor 9 is sequentially inserted from the front toward the back. Thereby, the end face electrode 11 is connected to the side face electrode 13 of the adjacent capacitor 9 by the bus bar 21. Further, the second fixing case 45 is provided with a lower fixing screw hole 49, and by fixing the lower fixing screw 51 to the fixing bar 41 arranged at the position of the lower fixing screw hole 49, the fixing bar 41 is fixed. The second fixing case 45 is fixed.

  FIG. 4 shows a state where the above components are assembled. The first fixed case 33 and the second fixed case 45 are connected by a fixed rod 41, and the capacitor 9 is firmly fixed by being sandwiched between the first fixed case 33 and the second fixed case 45. Yes.

  The bus bar 21 and the L-shaped bus bar 27 are firmly connected to the projecting portion 19 by laser welding the portions marked with x shown in FIG. In FIG. 4, multiple points are welded in a spot shape, but this may be performed in a line shape by sequentially shifting the welding position. In this case, the connection is stronger than in the case of spot welding. The conductive portion 29 disposed on the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 inserts and connects the terminal portion 31 into the connection hole 53 a provided in the circuit board 53. It protrudes from the end opening 35a.

  The circuit board 53 has a voltage balance circuit (not shown). The circuit board 53, the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 are connected to each other through the conductive part 29 and the connection hole 53a. By electrically connecting, the voltage of each capacitor 9 is measured and controlled.

  Further, the screw hole 25 provided in the end bus bar 23 is fastened and fixed to the insert nut 37 of FIG. . At this time, the screw 59 is tightened via the washer 61. The external bus bar 55 is provided with an external bus bar bent portion 63, and the possibility that the external bus bar 55 is damaged by absorbing the stress due to vibration or heat is reduced.

  When the above members are assembled, the capacitor unit shown in FIG. 5 is completed.

  The circuit board 53 is installed on the upper part of the first fixed case 33, and the terminals provided on the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 in the connection hole 53a as described with reference to FIG. The part 31 is inserted and connected by soldering. The screw 59 is inserted and fixed in the external bus bar screw hole 57, and the capacitor unit is electrically connected to the external wiring via the external bus bar 55.

  Next, FIG. 6 shows a cross-sectional view of a rectangular portion indicated by a dotted line in FIG.

  As is clear from FIG. 6, by providing the protrusion 19 higher than the end surface peripheral portion 17, the bus bar 21 and the end surface peripheral portion 17 are prevented from contacting and short-circuiting. Furthermore, a space is provided between adjacent capacitors 9 so that the capacitors 9 do not come into contact with each other to cause a short circuit.

  The pressure regulating valve 15 is covered with a cover portion 33a formed on the first fixed case 33, and is separated from the circuit board 53 and the bus bar 21 by the cover portion 33a. Further, the pressure regulating valve 15 is configured to have a height lower than that of the end surface peripheral portion 17, and there is a gap between the pressure regulating valve 15 and the cover portion 33 a disposed above the pressure regulating valve 15. Therefore, since the discharge hole 15a is not blocked, the electrolyte solution vaporized from the discharge hole 15a in FIG. 1 is normally discharged.

  As shown in FIG. 6, the terminal portion 31 has a shape protruding from the conductive portion 29, and the diameter of the connection hole 53 a in FIG. Is not inserted below the terminal portion 31, and a gap 65 exists between the circuit board 53 and the first fixed case 33 by the amount that the conductive portion 29 protrudes from the first fixed case 33. Therefore, since the height of the screw head of the upper fixing screw 43 is lower than the height of the gap 65, the possibility that the screw head of the upper fixing screw 43 contacts the circuit board 53 is reduced.

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

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

  As shown in FIG. 1, a plurality of capacitors 9 each having an end face electrode 11 and a side electrode 13 are arranged side by side, and among the plurality of capacitors 9 arranged side by side, adjacent capacitors 9 are arranged. This is because the end face electrodes 11 and the side face electrodes 13 are connected by the bus bar 21.

  With this configuration, the conductive portion 29 can be provided on the flat portion 21 b of the bus bar 21 that connects the capacitors 9, and each bus bar 21 can be connected to a single circuit board 53 via the conductive portion 29. At this time, the voltage of the bus bar 21 detected by the voltage circuit provided on the circuit board 53 is substantially equal to the voltage of the end face electrode 11 and the side face electrode 13 to which each bus bar 21 is connected. As a result, the voltage across the capacitor 9 can be measured and controlled with a single circuit board 53, and the capacitor unit can be reduced in size and weight.

  Moreover, as shown in FIG. 3, it is good also as a structure which provides the bending part 21c in the flat part 21b of the bus-bar 21. As shown in FIG. Thereby, the bending portion 21c absorbs the stress generated in the bus bar 21 due to heat and vibration, and the possibility that the bus bar 21 is damaged can be reduced. In particular, when the capacitor unit is mounted on a vehicle, strong vibration may be transmitted, and thus the capacitor unit is required to have vibration resistance. Therefore, this configuration is useful as a capacitor unit for vehicles.

  As shown in FIG. 6, the pressure regulating valve 15 is configured to be separated from the circuit board 53 and the bus bar 21 by facing the cover portion 33 a. Thereby, even if the electrolytic solution evaporated from the discharge hole 15a is discharged, it does not adhere to the circuit board 53 and the bus bar 21, and the possibility of corrosion can be reduced. Therefore, high reliability of the capacitor unit can be obtained.

  The capacitor 9 may be arranged in a horizontally placed state, and the pressure regulating valve 15 may be arranged above the center of the end face electrode 11 of the capacitor 9. Even when the capacitor units are arranged in the horizontal direction in this way, the voltage of each capacitor 9 can be obtained by the circuit board 53 provided only on the end face electrode 11 side of the capacitor 9 by using the configuration of the first embodiment. It is possible to measure, and the capacitor unit can be reduced in size and weight. Further, in this configuration, even when the circuit board 53 is provided on the second fixed case 45 side, the capacitor unit is placed in the horizontal direction, so that the circuit board 53 is affected by the weight of the capacitor 9. It does not receive and the possibility of breakage is reduced. Further, since the pressure regulating valve 15 is disposed above the center of the end face electrode 11 of the capacitor 9, the possibility that the electrolyte solution leaks from the discharge hole 15a can be reduced. In addition, since the capacitor unit mounted on the vehicle is often mounted under the floor and requires a low profile, as described above, if the capacitor unit is placed in a parallel horizontal state and the overall height is lowered, It is suitable as a capacitor unit.

  In the first embodiment, as shown in FIG. 2 (a), the circumferential portion 21a of the bus bar 21 is fitted into the side electrode 13 of the capacitor 9 in advance, and as shown in FIG. The side electrode 13 is joined by welding. Thereafter, as shown in FIG. 4, the capacitor 9 is inserted and held in the first fixed case 33 and the second fixed case 45, and then the flat portion 21 b of the bus bar 21 and the end face electrode 11 of FIG. 1 through the bus bar opening 35. The protruding portion 19 is welded.

  Even if manufactured in this way, the capacitor unit can be reduced in size and weight, but there is a dimensional error in the height direction in the protruding portion 19 of the capacitor 9 or the end face electrode 11. In this case, in the above manufacturing method, when the flat portion 21b and the protruding portion 19 are welded together, they are not necessarily in close contact due to the dimensional error. Therefore, it is necessary to press the flat portion 21b in order to perform reliable welding. When welding is performed in this manner, tensile stress and compressive stress are applied to the welded portion and the bus bar 21. When the capacitor unit in this state is used in a vehicle, excessive stress is applied to the welded portion and the bus bar 21 due to vehicle vibration, so that the joint portion may be peeled off or the bus bar 21 may be damaged.

  In order to avoid this, the following manufacturing method may be employed. First, as shown in FIG. 2A, the circumferential portion 21a is fitted into the side electrode 13, and in this state, the capacitor 9 is connected to the first fixed case 33 and the second fixed case 45 without welding them together. Insert into. Next, the flat portion 21b of the bus bar 21 and the protruding portion 19 of the end face electrode 11 are welded. At this stage, even if there is a dimensional error in the height direction of the protruding portion 19 of the capacitor 9 or the end face electrode 11, the circumferential portion 21a can move along the length direction of the side electrode 13, so that the flat portion 21b. Can be welded in a state in which the protruding portion 19 is in close contact. As a result, when the bus bar 21 and the protruding portion 19 of the end face electrode 11 are welded, stress due to dimensional errors is not applied to the welded portion of the flat portion 21b and the protruding portion 19 or the bus bar 21. Further, since the circumferential portion 21a and the side electrode 13 are in close contact with each other without any stress being applied to the bus bar 21, the circumferential portion 21a and the side electrode 13 are welded and joined in this state. As a result, the stress due to the dimensional error is finally not applied to all the welded portions and the bus bar 21.

  By adopting such a capacitor unit manufacturing method, even if vehicle vibration is applied, excessive stress is not applied to the welded portion and the bus bar 21, and high reliability can be obtained.

(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. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals.

  The configuration of the capacitor unit according to the second embodiment differs from the configuration of the first embodiment in the following points as shown in FIG.

  1) On the upper surface of the first fixed case 33, a bus bar hole 71 for inserting a connection portion with the side electrode 13 of the bus bar 21 (also referred to as the circumferential portion 21a in the second embodiment) is provided.

  2) Accordingly, the circumferential portion 21 a of the bus bar 21 is inserted into the bus bar hole 71 from the upper surface of the first fixed case 33, so that the flat portion 21 b of the bus bar 21 is disposed on the upper surface of the first fixed case 33. The

  3) Since only the protrusion 19 welded to the flat portion 21b needs to appear on the upper surface of the first fixed case 33 by the above configuration, the bus bar opening 35 has a shape (specifically, the protrusion 19 can appear). Is a shape slightly larger than the shape of the protrusion 19.

  4) When the circumferential portion 21 a is inserted into the bus bar hole 71, the through hole 73 is provided at a position facing the circumferential portion 21 a on the side surface of the first fixed case 33.

  The configuration other than the above is the same as that of the first embodiment. Therefore, also in the configuration of the second embodiment, the capacitor unit can be reduced in size and weight and have high reliability for the same reason as in the first embodiment. The shapes of the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 are different in detail from the first embodiment, but all have the same components as those in the first embodiment. Further, although the position of the pressure regulating valve 15 is different from that of the first embodiment, this is not particularly limited to the position of FIG. 7 and may be the same position as that of the first embodiment.

  Next, a method for manufacturing such a capacitor unit will be described.

  First, a plurality of (four in the second embodiment) fixing rods 41 are arranged so as to face the lower fixing screw holes 49 and fixed by tightening the lower fixing screws 51.

  Next, the upper surface of the plurality of capacitors (5 in the second embodiment) having the end face electrodes 11 is provided in a holding hole (not shown) provided in the first fixed case 33, and the bottom surface is provided in the second fixed case 45. Are inserted into the holding holes 47 respectively. At this time, the protrusion 19 is inserted so as to be fitted into the bus bar opening 35. As a result, the circumferential position of each capacitor 9 is determined. Further, by inserting the upper surface of the capacitor 9 into the holding hole provided in the first fixed case 33, a gap substantially equal to the thickness of the bus bar 21 is formed between the holding hole and the side electrode 13. Yes. This gap communicates with the bus bar hole 71.

  Next, the upper fixing screw 43 is fastened to the fixing bar 41 through the upper fixing screw hole 39. The capacitor 9 is held by the first fixed case 33 and the second fixed case 45 through the steps so far.

  Next, the bus bar 21 and the circumferential portion 21 a of the end bus bar 23 are inserted into the bus bar hole 71. Thus, the circumferential portion 21 a is inserted into the gap between the holding hole and the side electrode 13 through the bus bar hole 71. Accordingly, the bus bar 21 and the end bus bar 23 are accurately positioned by the bus bar hole 71 in a state where the circumferential portion 21 a is in close contact with the side electrode 13. At the same time, adhesion between the flat portion 21b and the protruding portion 19 is obtained. At this time, the surface of the circumferential portion 21 a is exposed in the through hole 73.

  FIG. 8 shows the positional relationship between the bus bar 21 and the capacitor 9 when the circumferential portion 21 a of the bus bar 21 is inserted into the bus bar hole 71. FIG. 8 shows only one set of capacitor 9 and bus bar 21 for the sake of clarity, and the drawing of the first fixed case 33 is omitted. As shown in FIG. 8, the circumferential portion 21 a is in close contact with the side electrode 13 as described above. Further, it can be seen that the flat portion 21b is disposed so as to be in close contact with the upper surface of the protruding portion (not shown) of the adjacent capacitor.

  As described above, according to the second embodiment, the positioning and adhesion of the bus bar 21 can be obtained very easily, so that the assembly workability can be improved.

  Since the L-shaped bus bar 27 is not inserted into the bus bar hole 71, positioning is performed by tightening a temporary set screw (not shown) into the insert nut 37 through the screw hole 25 when positioning. Thereby, the close contact between the flat portion 21b of the L-shaped bus bar 27 and the protruding portion 19 is also obtained.

  The capacitor unit assembled so far is shown in FIG. At this stage, each capacitor 9 is held by the first fixed case 33 and the second fixed case 45, and the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 are positioned. Next, first, the bus bar 21 and the flat portion 21b of the L-shaped bus bar 27 and the protruding portion 19 of the end face electrode 11 of FIG. In FIG. 9, the welded portion is marked with a cross. Thus, even if there is a dimensional error in the height direction of the protruding portion 19 of the capacitor 9 or the end face electrode 11 by first welding the flat portion 21b and the protruding portion 19, the circumference is the same as in the first embodiment. Since the portion 21a can move along the length direction of the side electrode 13, it can be welded in a state where the flat portion 21b and the protruding portion 19 are in close contact with each other. Stress due to dimensional error is not applied.

  In this state, the circumferential portion 21 a and the side electrode 13 are in close contact with each other without any stress being applied to the bus bar 21, and then the circumferential portion 21 a and the side electrode 13 are welded and joined via the through hole 73. This welded portion is also indicated by a cross in FIG. By such a manufacturing method, finally, stress due to the dimensional error is not applied to all the welded portions and the bus bar 21. Therefore, even if vehicle vibration is applied, excessive stress is not applied to the welded portion and the bus bar 21, and high reliability can be obtained. Further, since the welding of the circumferential portion 21a and the side electrode 13 is performed through the through hole 73, the step of welding while rotating the capacitor 9 as in the first embodiment becomes unnecessary.

  Thereafter, as in the first embodiment, the terminal portion 31 is inserted into and connected to the connection hole 53a of the circuit board 53, and the external bus bar 55 for electrical connection to the outside is connected to the L-shaped bus bar 27 with the screw 59. The capacitor unit is completed by fixing with. Although not shown, the external bus bar 55 is similarly fixed to the end bus bar 23.

  With the above configuration and manufacturing method, a capacitor unit that can be reduced in size and weight, is highly reliable, and has improved assembly workability can be realized.

  In the second embodiment, after the flat portion 21b of the bus bar 21 and the protruding portion 19 of the end face electrode 11 are welded and joined, the circumferential portion 21a and the side electrode 13 are welded and joined through the through hole 73. Although it is manufactured, it may be manufactured in the reverse process, particularly when the bus bar 21 is thick. However, when the bus bar 21 is thin, thermal stress due to welding is applied to the bus bar 21 when the flat portion 21b and the protruding portion 19 are welded. At this time, if the circumferential portion 21a and the side electrode 13 are previously welded, the circumferential portion 21a cannot move, so that the thermal stress remains, and an excessive stress may be applied due to vehicle vibration. For this reason, the step of welding and joining the circumferential portion 21a and the side electrode 13 after the flat portion 21b and the protruding portion 19 are welded regardless of the thickness of the bus bar 21 is desirable.

  Similarly to the first embodiment, the capacitor 9 may be arranged in a horizontally placed state, and the pressure regulating valve 15 may be arranged above the center of the end face electrode 11 of the capacitor 9. In this case, in the second embodiment, if the through hole 73 is arranged on the upper side in FIG. 9, the pressure regulating valve 15 is arranged on the upper side of the center of the end face electrode 11 of the capacitor 9.

  In the second embodiment, as shown in FIG. 7, the circumferential portion 21a has a length of about 1/3 of the circumference of the capacitor 9, but this may be longer. In this case, for example, if the circumferential portion 21a is approximately 2/3 of the circumference of the capacitor 9 as in the first embodiment, the through hole 73 is also provided on the side surface on the back side of the first fixed case 33. As a result, since the circumferential portion 21a can be welded from both sides, the reliability can be further improved and the contact resistance of the welded portion can be reduced.

  Further, a bent portion similar to that of the first embodiment may be provided on part of the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27, for example, the flat portion 21b. Thereby, the stress to the bus bar 21, the end bus bar 23, and the L-shaped bus bar 27 due to thermal expansion or the like can be reduced.

  In the first and second embodiments, the cylindrical capacitor 9 is employed. However, the present invention is not limited thereto, and a capacitor having a prism shape or other shapes may be employed. In this case, what is necessary is just to change suitably the shape of the circumference part 21a according to the shape of a capacitor.

  The capacitor unit according to the present invention can measure and control the voltage across each capacitor on a single circuit board by means of the conductive portion provided on the flat portion of the bus bar connecting the capacitors. As a result, the capacitor unit can be reduced in size and weight, and thus can be effectively used as a capacitor unit as an auxiliary power source for a vehicle.

1 is an exploded perspective view of a capacitor unit according to Embodiment 1 of the present invention. 1 shows a method for welding a capacitor and a bus bar according to Embodiment 1 of the present invention, where (a) is a perspective view before welding of the bus bar and the capacitor, and (b) is a perspective view after welding of the bus bar and the capacitor. The perspective view of the bus-bar in the other form of this 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 perspective view which shows the positional relationship of the capacitor of the capacitor unit and bus bar in Embodiment 2 of this invention The partial assembly perspective view of the capacitor unit in Embodiment 2 of this invention A perspective view of a conventional battery unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 9 Capacitor 11 End surface electrode 13 Side surface electrode 15 Pressure regulation valve 15a Emission hole 17 End surface surrounding part 19 Protrusion part 21 Bus bar 21a Circumferential part 21b Flat part 21c Bending part 23 End part bus bar 25 Screw hole 27 L-shaped bus bar 29 Conductive part 31 Terminal Part 33 First fixing case 33a Cover part 35 Bus bar opening 35a End opening 37 Insert nut 39 Upper fixing screw hole 41 Fixing bar 43 Upper fixing screw 45 Second fixing case 47 Holding hole 49 Lower fixing screw hole 51 Lower part Fixing screw 53 Circuit board 53a Connection hole 55 External bus bar 57 External bus bar screw hole 59 Screw 61 Washer 63 External bus bar bent part 65 Air gap 71 Bus bar hole 73 Through hole

Claims (7)

A plurality of capacitors having end face electrodes on one end face and side electrodes having a polarity different from that of the end face electrode from the other end face to the side face,
A bus bar connected to the end face electrode of the capacitor and partially connected to the side face electrode of the adjacent capacitor;
A circuit board disposed on the one end face side of the plurality of capacitors,
A capacitor unit in which the bus bar and the circuit board are electrically connected via a conductive portion provided from the bus bar toward the circuit board. The capacitor unit according to claim 1, wherein a bent portion is provided in the vicinity of one end face electrode connecting portion of the bus bar. A first fixing case and a second fixing case for holding the capacitors in parallel with each other by inserting the one end face having the end face electrode of the capacitor and the other end face;
A bus bar hole for inserting a connection portion with the side electrode of the bus bar provided on the upper surface of the first fixed case;
2. The capacitor unit according to claim 1, further comprising a through hole provided at a position facing the connection portion on a side surface of the first fixed case when the connection portion is inserted into the bus bar hole. A first fixing case and a second fixing case for holding the capacitors in parallel with each other by inserting the one end face having the end face electrode of the capacitor and the other end face;
A pressure regulating valve provided on one end surface or the other end surface of the capacitor,
2. The capacitor unit according to claim 1, wherein the first fixed case or the second fixed case is provided with a cover portion that separates the pressure regulating valve from the bus bar and the circuit board. 5. The capacitor unit according to claim 4, wherein the plurality of capacitors are disposed in a horizontally placed state parallel to each other, and the pressure regulating valve is disposed above a center axis of the capacitor. A plurality of capacitors having end face electrodes on one end face and side electrodes having a polarity different from that of the end face electrode from the other end face to the side face,
A bus bar connected to the end face electrode of the capacitor and partially connected to the side face electrode of the adjacent capacitor;
A circuit board disposed on the one end face side of the plurality of capacitors;
A conductive portion provided from the bus bar toward the circuit board, and electrically connecting the bus bar and the circuit board;
A first fixing case and a second fixing case for holding the capacitors in parallel with each other by inserting the one end face having the end face electrode of the capacitor and the other end face;
With the connection portion of the bus bar connected to the side electrode inserted into the side electrode, the capacitor is inserted into the first fixed case and the second fixed case,
After welding the bus bar and the end face electrode,
A method for manufacturing a capacitor unit, wherein the connection portion and the side electrode are welded. A plurality of capacitors having end face electrodes on one end face and side electrodes having a polarity different from that of the end face electrode from the other end face to the side face,
A bus bar connected to the end face electrode of the capacitor and partially connected to the side face electrode of the adjacent capacitor;
A circuit board disposed on the one end face side of the plurality of capacitors;
A conductive portion provided from the bus bar toward the circuit board, and electrically connecting the bus bar and the circuit board;
A first fixing case and a second fixing case for holding the capacitors in parallel with each other by inserting the one end face having the end face electrode of the capacitor and the other end face;
A bus bar hole for inserting a connection portion with the side electrode of the bus bar provided on the upper surface of the first fixed case;
When the connection portion is inserted into the bus bar hole, a through hole provided at a position facing the connection portion on the side surface of the first fixed case,
In the state where the capacitor is inserted and held in the first fixed case and the second fixed case, the connection portion is inserted into the bus bar hole,
After welding the bus bar and the end face electrode,
A method for manufacturing a capacitor unit, wherein the connection portion and the side electrode are welded and joined through the through hole.

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