JP3456038B2 - Equipment for manufacturing electrode foil for electrolytic capacitors - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing an electrode foil used for an electrolytic capacitor, and more particularly to an apparatus for bonding an aluminum foil to an electrode tab. [0002] Electrode foils used in electrolytic capacitors are:
A strip-shaped aluminum foil etched and expanded,
It has a structure in which an electrode tab made of a material such as aluminum and having an external lead wire connected to the outside connected to the outside is welded to the electrode tab. The anode electrode foil and the cathode electrode foil thus configured are wound together with the separator to form a capacitor element. In joining the aluminum foil and the electrode tab, it is necessary to electrically connect the aluminum foil and the electrode tab together with the mechanical connection between the aluminum foil and the electrode tab. Various connection methods have heretofore been proposed, in which a method of connecting an aluminum foil and an electrode tab by a cold welding method (cold welding) is known. [0004] An outline of the joining method utilizing the cold pressure welding will be described below. As shown in FIG. 6, first, the aluminum foil 1 and the electrode tab 2 are overlapped at a predetermined position, and the electrode tab 2 side is placed on the pedestal 4. Then, the dice 4 arranged at a position facing the pedestal 4 are moved in the direction of the arrow in FIG. 6A, and the dies 3 and the pedestal 4 are abutted. The moving process of the die 3 at this time is up to a position where the aluminum foil 1 is pressed and bitten into the electrode tab 2. When the die 3 and the pedestal 4 are butted, the temperature where the die 3 and the aluminum foil 1 or the electrode tab 2 come into contact locally and instantaneously becomes high due to friction. At the same time, a shock is applied when the butts are joined. Then, the aluminum atoms constituting the aluminum foil 1 and the electrode tabs 2 are diffused into the atoms, respectively, and enter into each other. At the contact surface between the aluminum foil 1 and the electrode tab 2, a new metal bond is generated between the aluminum atoms of the aluminum foil 1 and the electrode tab 2, so that the aluminum foil 1 and the electrode tab 2 are mechanically and electrically strongly bonded. Thereafter, the die 3 and the pedestal 4 are separated from the electrode tab 2 and the aluminum foil 1 to complete the joining of the electrode tab 2 and the aluminum foil 1,
Obtain electrode foil. In the case where the aluminum foil 1 and the electrode tab 2 are cold-welded, the die 3 may be cut into the aluminum foil 1 and the electrode tab 2 when they are connected by the cold welding method. . Then, in order to separate the die 3 from the aluminum foil 1 and the electrode tab 2, when the die 3 is moved in the direction of the arrow in FIG.
As shown in FIG. 6C, the electrode tab 2 also moves with the movement of the die 3 because the die 3 is engaged with the aluminum foil 1 and the electrode tab 2. They will be separated. Therefore, a step for separating the die 3 and the electrode tab 2 is required, which causes an increase in the number of steps. [0006] Alternatively, the pedestal 4 and the aluminum foil or the electrode tab 2 may be cut off. Also in this case, a step of separating the pedestal 4, the electrode tab 2, and the aluminum foil 1 is required, which causes an increase in the number of steps. [0007] Therefore, in order to remove the electrode foil from the die or pedestal, a conventional manufacturing apparatus having a configuration as shown in FIG. 4 has been employed. That is, the upper support member 6 is attached to the frame member 5 that moves in conjunction with the movement of the die 3 via the spring 9. The upper support member 6 is formed in a rectangular flat plate shape, and has a rectangular through-hole through which the die 3 is inserted at the center. A spring 9 is attached to a square of the upper support member 6. The lowermost end of the upper support member 6 is adjusted so as to be located below the tip of the die 3. A lower support member 7 supported by a spring 9 is also attached to the pedestal 4. The lower support member 7 has the same shape as the upper support member 6. The projecting portion 41 of the pedestal 4 is inserted into the through hole of the lower support member 7. The lower support member 7 is also provided with a square spring 9. Then, the aluminum foil 1 and the electrode tab 2 are arranged between the upper support member 6 and the lower support member 7. In such a manufacturing apparatus, the cold pressing method will be described together with its operation. When the die 3 is moved from top to bottom, first, the upper support member 6 comes into contact with the aluminum foil 1 and the electrode tab 2. Then, when the die 3 is further lowered, the aluminum foil 1 and the electrode tab 2 also come into contact with the lower support member 7. Then, as the die 3 descends, the upper support member 6 and the lower support member 7
Is contracted. Further, when the die 3 moves and the die 3 and the pedestal 4 abut against each other, the cold pressing of the aluminum foil 1 and the electrode tab 2 is completed. Thereafter, the die 3 is detached from the pedestal 4. At this time, even if the aluminum foil 1 and the electrode tab 2 are cut into the die 3, the upper support member 6 and the lower support member 7
The aluminum foil 1 and the electrode foil 2 are pressed upward and downward by the upper support member 6 and the lower support member 7 by the elastic force of the spring 9 for supporting the die 3 or the pedestal 4, the aluminum foil 1 and the electrode tab 2 respectively. Comes off. Then, as the die 3 further rises, the upper support member 6 also rises. At the stage when the aluminum foil 1 and the electrode tab 2 have been joined, they are transported. [0008] However, according to the conventional manufacturing apparatus, at the moment when the die and the pedestal abut, the electrode tab and the aluminum foil are sandwiched between the upper support member and the lower support member. It has become. When the die and the pedestal are abutted in such a state, the impact at the time of the abutment between the die and the pedestal becomes stress and propagates to the electrode tab and the aluminum foil. Then, the stress propagated to the electrode tabs and the aluminum foil concentrates on the portions in contact with the respective support members, and local stress concentration occurs. For this reason, in a portion where the stress concentration occurs, a break or a crack may occur. Accordingly, an object of the present invention is to provide an aluminum foil and an electrode tab which are joined together by a cold pressure welding method without applying mechanical stress to the aluminum foil and the electrode tab. It is another object of the present invention to reliably remove the dice from the cold-pressed electrode foil and more efficiently manufacture the electrode foil. According to the present invention, an aluminum foil and an electrode tab are placed between a die and a pedestal, and the aluminum foil and the electrode tab are cold-pressed by abutting the die and the pedestal. An apparatus for manufacturing an electrode foil for an electrolytic capacitor, comprising: a frame member moving with the die; an upper support member attached to the frame member by an elastic member and attached to a position closer to the aluminum foil than the tip of the die; A lower support member on which an aluminum foil and an electrode tab are mounted by an elastic member, and a locking means for setting an interval so that the upper support member and the lower support member do not come into contact when the die and the pedestal abut against each other. It is characterized by having been provided. After the cold welding is completed, even if the aluminum foil and the electrode tab are in a state of being cut into the die,
When the die is lifted, the electrode foil that has been cut by the die rises with the movement of the die, and first comes into contact with the upper support member. When the die further rises, the electrode foil is subjected to a force in a direction in which the electrode foil is separated from the die by the elastic force of the elastic member supporting the upper support member, and the die and the electrode foil are separated. Also, even if the pedestal and electrode foil are in a state of being cut off, as the die rises,
Since a force is applied in the direction in which the electrode foil separates from the pedestal due to the elasticity of the elastic member of the lower support member, the electrode foil that has eroded the pedestal also comes off. Further, in the manufacturing apparatus of the present invention, there is a gap between the upper support member and the lower support member at the time of cold pressing, so that each support member does not contact the electrode foil at the same time. When the pedestals are abutted, the stress applied to the electrode tab and the aluminum foil propagates and is dispersed throughout the electrode tab and the aluminum foil, and local stress concentration does not occur. Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a drawing showing only a main part of the manufacturing apparatus of the present invention. FIG. 2 is a sectional view showing the operation of each step by the manufacturing apparatus of the present invention. Also, the same reference numerals are given to the same components as those in the conventional example. Reference numeral 1 shown in FIG. 1 is an aluminum foil, which is formed of high-purity aluminum in the form of a strip, and further subjected to etching to enlarge the surface to a desired magnification.
Reference numeral 2 denotes an electrode tab, which is also made of high-purity aluminum, has a flat portion and a continuous round bar portion on the flat portion, and an external lead 21 wire is welded to the tip of the round bar portion. Is what it is. Further, the thickness of the flat portion of the electrode tab 2 is formed to be thicker than the thickness of the aluminum foil 1,
It is formed so that it is not easily bent. Then, the electrode tab 2 and the aluminum foil 1 are overlapped. In this case, the flat portion of the electrode tab 2 overlaps the aluminum foil 1. As shown in FIG. 1, the electrode tab 2 and the aluminum foil 1 which are overlapped are arranged at a predetermined position between the upper support member 6 and the lower support member 7 so that the electrode tab 2 is on the lower side. I do. The upper support member 6 has a structure as shown in FIG. 3 and is formed in a rectangular flat plate shape, and a rectangular through hole is formed in an intermediate portion thereof. The dies 3 are inserted into the through holes. A projection 61 is formed in the square. A spring 9 is attached to a square of the upper support member 6, and the other end of the spring 9 is attached to the frame member 5. The frame member 5 is attached to the die 3 and is formed so as to move in conjunction with the die 3. For this reason, the upper support member 6 is movable in the moving direction of the die 3 due to the elasticity of the spring, that is, in the vertical direction in this drawing. The die 3 has a structure that can be moved vertically in FIG. 1 by driving means (not shown). The die 3 is made of high-hardness metal and has a prismatic cross section. The tip of the die 3 is tapered, and the tip surface is a rectangle having a smaller area than the cross section of the main body. In this embodiment, a die having a structure in which four dies 3 are connected at a root portion is used. Then, the four dies 3 move at the same time, and the cold welding is performed simultaneously at four locations. A pedestal 4 is disposed at a position facing the die 3. The pedestal 4 has a projection 41 formed thereon. A lower support member 7 is attached to the pedestal 4 via a spring 9. This lower support member 7 is shown in FIG.
As shown in FIG. 7, the structure is substantially the same as that of the upper support member 6, and the projecting portion 41 of the pedestal 4 is inserted into the central through hole. Further, a projection 71 is formed at a corner and one side of the lower support member 7. The lower support member 7 is movable vertically. Then, the die 3 is moved in the direction of the arrow in FIG. 2A, and the die 3 and the pedestal 4 are abutted to perform cold pressure welding between the aluminum foil 1 and the electrode tab 2. The operation at this time will be described. As the die 3 moves down, the frame member 5 and the upper support member 6 attached to the frame member 5 also move down. Then, as shown in FIG. 2B, the aluminum foil 1 and the electrode tab 2 come into contact with the main body of the upper support member 6. When the die 3 further descends, the aluminum foil 1 and the electrode tab 2 also descend. Since the lowermost end of the upper support member 6 is located lower than the tip of the die 3, the protrusion 61 of the upper support member 6 and the protrusion 71 of the lower support member 7 come into contact first. When the projections 61 and 71 contact each other, the main bodies of the upper support member 6 and the lower support member 7 are maintained in a state where they do not contact each other. Therefore, the aluminum foil 1 and the electrode tabs 2 sandwiched between the upper support member 6 and the lower support member 7 are also in a state where they are only in contact with the upper support member 6 but not in contact with the lower support member 7 . . When the die 3 is further lowered, FIG.
As shown in (1), the springs 9 supporting the upper support member 6 and the lower support member 7 are respectively contracted, and the die 3 and the pedestal 4 abut. In this case, the travel distance of the die 3 is as follows.
When the die 3 comes to the lowermost position, the tip of the die 3 presses the aluminum foil 1 and moves it to a position where it is cut into the electrode tab 2. In this cold pressure welding method, the temperature of the portion in contact with the die 3, the aluminum foil 1, and the electrode tab 2 is locally and instantaneously increased by friction. At the same time, a shock is applied when the butts are joined. Then, the metal atoms forming the aluminum foil 1 and the electrode tabs 2 are diffused into the atoms, and enter into each other. Then, since metal components of the mutual constituent metals are generated on the contact surface between the aluminum foil 1 and the electrode tab 2, the aluminum foil 1 and the electrode tab 2 are mechanically and electrically strongly bonded. Next, a step of separating the die 3 from the pedestal 4 after the completion of the cold pressing will be described. As shown in FIG. 2D, the die 3 is raised after the cold pressing is completed. At this time, if the electrode tab 2 or the aluminum foil 1 has been cut into the die 3,
With the die 3, the electrode tab 2 and the aluminum foil 1 also rise. When the die 3 further rises, the electrode tab 2 and the aluminum foil 1 come into contact with the upper support member 6. Since the upper support member 6 is supported by the spring 9, the elastic force of the spring 9 is applied in a direction in which the die 3 is separated from the aluminum foil 1 and the electrode tab 2 as the spring 9 expands. Therefore, when the die 3 is further raised, the elastic force of the spring 9 is applied to the aluminum foil 1 and the electrode tab 2 in a direction in which the aluminum foil 1 and the electrode tab 2 are separated from the die 3, and the aluminum foil 1 and the electrode foil 2 are separated from the die 3; It comes to rest on the lower support member 7. When the aluminum foil 1 and the electrode tabs 2 are on the pedestal 4 on the side of the pedestal 4, the spring 9 of the lower support member 7 is extended with the rise of the die 3, and the aluminum foil 1 and the electrode tabs The force to push out 2 is applied. Then, the electrode foil comes off the pedestal. As the ascent of the die 3 is further continued, the upper supporting member 6 is also separated from the lower supporting member 7. Then, when the electrode foil has risen to the predetermined position, the manufacturing process of the electrode foil is completed. Then, the electrode foil having been subjected to the cold pressure welding is transferred by a transfer means (not shown), and the electrode tab and the aluminum foil to be subjected to the next cold pressure welding are placed on the lower support member. The subsequent steps are the same. In this embodiment, as the space forming means for providing a space between the support member 6 and the lower support member 7, the protrusions 61 and 71 are formed on the support member 6 and the lower support member 7, respectively. However, the projection may be formed on only one of them. Further, in this embodiment, a die manufacturing apparatus in which a die is moved from top to bottom has been described.
The manufacturing apparatus may be configured such that the dies are arranged on the lower side and the dies are pushed up. According to the present invention, when the electrode foil and the electrode tab are joined by the cold pressure welding method, the joining can be performed without causing the electrode foil to break or the like. In addition, the separation of the electrode tab and the die is ensured, and the work is not interrupted due to the separation of the electrode tab and the die. Further, since the electrode foil and the electrode tab are supported after the completion of the pressure welding, the impact and stress at the time of the cold pressure welding are propagated and dispersed throughout the aluminum foil and the electrode tab.
Therefore, no local stress is applied, and there is no inconvenience such as breakage of the aluminum foil due to the concentration of the stress or cracking of the electrode tab.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing a main part of an apparatus for manufacturing an electrode foil for an electrolytic capacitor according to the present invention. FIG. 2 is a front view showing each step of the operation of the apparatus for manufacturing an electrode foil for an electrolytic capacitor according to the present invention. FIG. 3 is a perspective view showing the structure of an upper support member and a lower support member used in the present invention. FIG. 4 is a side view showing a main part of a conventional apparatus for manufacturing an electrode foil for an electrolytic capacitor. FIG. 5 is a front view showing each step of the operation of the conventional apparatus for manufacturing an electrode foil for electrolytic capacitors. FIG. 6 is a view showing a method of connecting an electrode tab and an aluminum foil by a cold pressure welding method. [Description of Signs] 1 Aluminum foil 2 Electrode tab 21 External lead wire 3 Dice 4 Pedestal 41 Projection 5 Frame member 6 Upper support member 61 Projection 7 Lower support member 71 Projection 9 Spring

Claims (1)

(57) [Claim 1] An aluminum foil and an electrode tab are placed between a die and a pedestal, and the die and the pedestal are abutted to perform cold pressure welding of the aluminum foil and the electrode tab. An apparatus for manufacturing an electrode foil for an electrolytic capacitor, comprising: a frame member moving together with the dice; and an upper support member attached to the frame member by an elastic member and attached to a position closer to the foil than the tip of the die, The aluminum foil and the lower support member on which the electrode tab is mounted are attached to the pedestal by an elastic member, and when the die and the pedestal are abutted, the upper support member or the lower support member and the aluminum foil and the electrode foil are arranged. An apparatus for manufacturing an electrode foil for an electrolytic capacitor, comprising an interval forming means for forming an interval so as not to contact.