JP2006108380A - Manufacturing method of capacitor module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient connecting technique instead of TIG welding (inert gas shielded tungsten arc welding) between electric double layered capacitors so that a capacitor module having high performance can be produced efficiently. <P>SOLUTION: The capacitor module 10 is constituted of a manufacturing method wherein a required number of electric double layered capacitors 11 equipped with a pair of terminals 12 for a unit body are assembled in a predetermined arrayed condition, and, on the other hand, a plurality of electric double layered capacitors 11 neighbored in the arrayed direction of the capacitors 11 are connected in parallel to each one set of them, and respective sets are connected in series. The manufacturing method comprises a process for forming the terminals 12 of respective electric double layered capacitors 11 by high purity aluminum so as to have the shape of a sheet, a process for forming connecting members 13 among respective sets by the high purity aluminum so as to have the shape of a sheet, and a process for connecting the superposed parts 14, 15, 15 between the terminals 12 and the connecting members 13 by a spot welding machine from the thickness direction of the sheets under a predetermined welding condition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a capacitor module including an electric double layer capacitor having a pair of terminals and a unit body including a required number of electric double layer capacitors.

In recent years, electric double layer capacitors that can be rapidly charged and have a long charge / discharge cycle life are attracting attention as various power storage devices. In Patent Document 1, an electric double layer capacitor and a manufacturing method thereof are disclosed.
JP2003-124079

  Since the electric double layer capacitor has a low withstand voltage, when applied to a drive power source of an electric vehicle, the electric double layer capacitor is configured from a required number of electric double layer capacitors to a capacitor module (power storage device) having a predetermined capacity. Capacitor modules are required to minimize internal resistance in order to suppress charge / discharge loss, and TIG (Tungsten Inert Gas) is used as a joint between members for connecting a predetermined number of electric double layer capacitors to a predetermined wiring state. Welding is used.

  In the case of TIG welding, the work to be welded (members for connecting a predetermined number of electric double layer capacitors to a predetermined wiring state) is a thin aluminum plate, requiring skilled work while confirming the penetration of the welding rod In addition, cooling that protects the electric double layer capacitor from high heat accompanying welding is required, and it takes a long time to manufacture (produce) each capacitor module. Therefore, establishment of an efficient connection method to replace TIG welding is desired.

  It is an object of the present invention to provide a capacitor module and a method for manufacturing the same for realizing such a demand.

  The first invention collects a required number of electric double layer capacitors in a predetermined arrangement state in an electric double layer capacitor having a pair of terminals in a unit body, and a plurality of electric double layer capacitors adjacent to each other in the arrangement direction. In the method of manufacturing a capacitor module configured by connecting each pair in parallel and connecting each pair in series, the step of forming the terminals of each electric double layer capacitor in a plate shape from high-purity aluminum, It is characterized by comprising a step of forming a connecting member between the pairs in a plate shape from high-purity aluminum, and a step of joining these overlapping portions under a predetermined welding condition by a spot welder from the plate thickness direction.

  According to a second aspect of the present invention, in the method for manufacturing a capacitor module according to the first aspect, the spot welding machine is characterized in that welding conditions are set so as to form a nugget having a diameter of 3.5 mm at the welded portion.

  According to a third aspect of the present invention, in the method for manufacturing a capacitor module according to the first aspect, the spot welder is characterized in that the welding pressure is set to 0.6 kN.

  According to a fourth aspect of the present invention, in the method for manufacturing a capacitor module according to the first aspect, the spot welder includes a pair of arms that can be opened and closed around an X-shaped intersection, and a driving means that opens and closes the arms. The pair of arms are bent at the tip of the X shape in the shape of a square in the direction of mutual approach in order to secure the stroke required for welding within the narrow gap between each pair of electric double layer capacitors. It is characterized in that it is formed with a narrow electrode tip and a short setting electrode tip is provided at each tip.

  In the first invention, the members for connecting the required number of electric double layer capacitors to a predetermined wiring state can be easily and easily joined by spot welding without requiring skill. Spot welding has a short supply time of a large current to the work piece, and unlike arc welding such as TIG welding, cooling to protect the electric double layer capacitor from heat generated during welding is not required. High-purity (for example, 99.99%) aluminum is used for the workpiece. Although high-purity aluminum has low welding resistance, a good welded state can be obtained for joining members by spot welding under predetermined welding conditions. As a result, the time required for manufacturing (production) per unit can be significantly shortened for a high-performance capacitor module that uses high-purity aluminum for the terminals of the electric double layer capacitor and the connecting members between the groups. .

  In the second invention, spot welding is performed two points at a time under welding conditions set to form a nugget having a diameter of 3.5 mm, so that the connection resistance can be minimized to the same extent as TIG welding.

  In 3rd invention, a favorable welding state is obtained for joining of members, suppressing a deformation | transformation of high purity aluminum (to-be-welded object).

  In the fourth invention, the pair of openable and closable arms is formed to be narrow toward the tip by bending the X-shaped tip side into a U shape in the approaching direction, and the electrode tip at each tip is also set short. Therefore, it is easy to secure the arm stroke (opening / closing operation) necessary for spot welding in a narrow gap range between each set of electric double layer capacitors that are assembled in a predetermined arrangement state.

  FIG. 1 is a partial perspective view of a capacitor module 10 according to this embodiment. In order to constitute the capacitor module 10 having a predetermined capacity, a predetermined number of electric double layer capacitors 11 are assembled in a predetermined arrangement state. The predetermined number of electric double layer capacitors 11 are arranged not only in one column but in a plurality of columns, and in each column, two adjacent electric double layer capacitors 11 are connected in parallel one by one, and the groups are connected in series. Connected to. Each column is connected in series and parallel, and is composed into a power storage device (capacitor module) having a predetermined capacity as a whole.

  For the electric double layer capacitor 11, a laminated body composed of a positive electrode body, a negative electrode body, and a separator interposed therebetween, a pair of terminals 12 connected to each of the positive electrode body and the negative electrode body, and these terminals And a container that seals the laminate together with the electrolytic solution in a storage state in which a part of 12 protrudes to the outside. The positive electrode body and the negative electrode body are composed of a collector electrode and a polarizable electrode. The collector electrode is formed in a rectangular shape, and a strip-shaped lead is formed integrally with one side of the rectangular plane. Inside the container, the corresponding lead having the polarity is bonded to the pair of terminals 12.

  In FIG. 1, 12a and 12b are a pair of terminals (electrodes) protruding outside the electric double layer capacitor 11, and 13 is a member for connecting each pair in series. These are high purity (99.99%). It is made into a plate shape from aluminum. Flange 15 is formed at the tip of terminals 12a and 12b, and flange 14 is formed at both ends of connecting member 13. A pair of flanges 15 of the same-polarity terminals 12 and a flange 14 at one end of the connecting member 13 are overlapped, and by spot welding from the plate thickness direction, these three-layered flanges 15, 15, and 14 are joined. Is done. The flange 14 at the other end of the connecting member 13 is overlapped with the flange 15 of the adjacent pair of terminals 12 having the same polarity, and these are overlapped by spot welding from the plate thickness direction to thereby overlap these three-layer flanges 14 and 15. , 15 are joined. The connecting member 13 between each pair has one set of positive terminals 12a joined to one end 14a of the flange 14 at both ends, and one set of negative poles adjacent to the other end 14b of the flange 14 at both ends. The flanges 15 between the terminals 12b are joined.

  FIG. 2 shows a part (arm mechanism) of a spot welder used for joining the flange 15 of the terminal 12 and the flange 14 of the connecting member 13 in the manufacturing process of the capacitor module 10. The arms 21 and 22 are configured to be openable and closable via an X-shaped intersection 23 (pin). The distal end side B of the arms 21 and 22 is formed so as to be separable from the proximal end side A of the arms 21 and 22, and the rear end portion 24 of the distal end side B is fitted to the front end portion 26 on the proximal end side A. The front ends B of the arms 21 and 22 are bent in the shape of a dogleg in the approaching direction from the middle from the rear end portion 24 to the front end portion 25 so that the width of the arms 21 and 22 is narrowed toward the front end. The The distal end portion 26 has the smallest width of the arms 21 and 22, and a pair of electrode tips 28 are disposed at each distal end portion 26.

  As shown in FIG. 4, the electrode tip 28 is set to have a length shorter than that of the ready-made product. A core portion 29 (see FIG. 3) for mounting the electrode tip 28 is projected from the distal end portion 25 of the arms 21 and 22, and a hole 30 that fits into the core portion 29 without a gap is provided in the electrode tip 28. The length of the core portion 29 is also set shorter than the dimensions of the ready-made product. In the mounted state of the electrode tip 29, a chamber 31 (see FIG. 1) is formed at the back of the hole, and the arm 22 is provided with a coolant circulation path passing through the chamber 31. Reference numeral 33 denotes a part of the coolant circulation path, which is connected to a coolant supply source via a part of the circulation path (not shown).

  In FIG. 1, reference numeral 34 denotes a cylinder as a driving means for opening and closing the pair of arms 21 and 22. Since the workpiece is high-purity aluminum, the pressure between the electrode tips 28 is set to 0.6 kN. Reference numeral 35 denotes a secondary conductor of the welding transformer. When the switch 36 is turned on, the spot welder pressurizes an object to be welded between the electrode tips 28 by the operation of the cylinder 34 based on a predetermined welding condition, and generates a large current (second current generated in the secondary conductor of the welding transformer). Welding current) is supplied to the electrode tip 28.

  By such an arm mechanism, it is easy to secure the strokes (opening / closing operations) of the arms 21 and 22 necessary for spot welding in the range of the narrow gap d between each pair of the electric double layer capacitors 11 gathered in a predetermined arrangement state. Become. In addition, the stroke of the cylinder 34 is shortened, and the cylinder 34 can be reduced in size in combination with the pressure applied between the electrode tips 28 being set small.

  In the manufacturing process of the capacitor module 10, a step of forming the terminals 12 of the electric double layer capacitor 11 in a plate shape from high-purity aluminum (processed during the manufacturing process of the electric double layer capacitor 11), and connection between each set The step of forming the member 13 in a plate shape from high-purity aluminum, the step of forming flanges at both ends of the connection member 13, the step of forming the flange 15 at the tip of the terminal 12 (during the manufacturing process of the electric double layer capacitor 11) A step of assembling a predetermined number of electric double layer capacitors 11 in a predetermined arrangement state, a portion where the flanges 15 of the terminals 12 and the flanges 14 of the connecting members 13 overlap each other with a spot welder from the plate thickness direction. A process for joining under welding conditions is set.

  Predetermined welding conditions are as follows: Three overlapping flanges 15, 15, and 14 of two terminals 12 having a thickness of 0.6 mm and one connecting member 13 having a thickness of 0.8 mm are joined by spot welding from these thickness directions. In this case, the welding current is set to 19000 A, the energization time is set to 6 cyc (1 cys is 20 ms), and the applied pressure is set to 0.6 kN.

  FIG. 5 shows a part of the test results of spot welding, and the welding conditions are exemplified by TRY1 to TRY3. Confirmation item (1) “Connection resistance by welding” is 0.07 mΩ or less for all three cases, and in the case of TRY1, the confirmation item (2) “nugget diameter” is as small as 2.5 mm in diameter. Assuming that it is installed, there is a high possibility of peeling due to body vibration, and it is disqualified. In the case of TRY3, with regard to the confirmation item (4) “Guntip welding”, welding with the work piece is seen on both electrode tips by welding at the first point, and post-treatment is cumbersome and difficult to adopt. In the case of TRY2, the confirmation item (4) “Guntip welding” is found on one of the electrode tips by the second welding, but the confirmation item (2) “Nugget diameter” is 3.5 mm in diameter, Is recognized. Items to be confirmed (3) As for “generated temperature”, the generated temperature is much lower than the temperature (70 ° C.) or higher at which the thermal influence on the electric double layer capacitor 11 is a concern.

  By establishing the welding conditions in this manner, even when the work piece is a high-purity (99.99%) aluminum plate, it is possible to obtain a good joined state by spot welding. Since spot welding can be easily and easily performed only by a switch operation, it is possible to efficiently join the members that connect the required number of electric double layer capacitors 11 to a predetermined wiring state without requiring skill. . In the spot welding, unlike arc welding such as TIG welding, it is not necessary to confirm the penetration of the welding rod, and cooling for protecting the electric double layer capacitor 11 from the heat generated by welding becomes unnecessary. As a result, the time required for manufacturing (production) per unit of the high-performance capacitor module 10 that uses high-purity aluminum for the terminal 12 of the electric double layer capacitor 11 and the connecting member 13 between each set is greatly reduced. can do.

It is a one part perspective view explaining to composition of a capacitor module. It is a front view explaining the arm mechanism of a spot welder. It is a front view explaining a part (tip side) of an arm. It is the front view and left side view of an electrode chip. It is a table | surface which shows a part of test result of spot welding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Capacitor module 11 Electric double layer capacitor 12 Terminal 13 Connection member 14,15 Flange 21,22 Arm 23 Pin 25 Arm tip part 28 Electrode chip 29 Core part

Claims (4)

  While a required number of electric double layer capacitors are assembled in a predetermined arrangement state with an electric double layer capacitor having a pair of terminals as a unit, a plurality of electric double layer capacitors adjacent in the arrangement direction are arranged in parallel one by one In the method of manufacturing a capacitor module configured by connecting and connecting each set in series, a step of forming a terminal of each electric double layer capacitor in a plate shape from high-purity aluminum, a connecting member between each set A method of manufacturing a capacitor module comprising: forming a plate from high-purity aluminum; and joining these overlapping portions from a plate thickness direction using a spot welder under a predetermined welding condition.   2. The method of manufacturing a capacitor module according to claim 1, wherein the spot welding machine has welding conditions set so as to form a nugget having a diameter of 3.5 mm in a welded portion.   The method of manufacturing a capacitor module according to claim 1, wherein the spot welding machine has a welding pressure of 0.6 kN.   The spot welder includes a pair of arms that can be opened and closed around an X-shaped intersection, and a driving means that opens and closes these arms. 2. The method of manufacturing a capacitor module according to claim 1, further comprising an electrode chip that is bent into a garlic shape and is narrowly formed at the tip, and each tip has a short setting.