JP4193401B2 - Manufacturing method of electrolytic capacitor lead wire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an electrolytic capacitor lead wire connected to an electrode of an electrolytic capacitor element.
[0002]
[Background]
For example, as shown in FIG. 6, the electrolytic capacitor includes a lead wire 102 connected to each of the electrode foils 100 on the anode side and the cathode side. The lead wire 102 includes a flat wire connected to the electrode foil 100. A device in which a rod-like external lead 108 is integrated by welding to an element side lead 106 provided with a portion 104 is used. Reference numeral 110 denotes a welded portion between the element side lead 106 and the external lead 108.
[0003]
[Prior art]
Incidentally, for example, as shown in FIG. 7, the element-side lead 106 includes a flat portion 104 formed by processing a round bar-shaped wire, and a non-flat portion 112 having an outer shape of the wire. A flat end surface 114 as a welding surface is formed at the end. On the other hand, the external lead 108 is formed by sharpening a round bar-like wire rod to form an acute-angled tip portion 116 composed of two inclined surfaces, and the acute-angled tip portion 116 is pushed against the end surface 114 of the element-side lead 106. Arc welding is performed to form the lead wire 102. For example, Japanese Patent Application Laid-Open No. 7-2111597 “Method for Manufacturing Lead Wire for Electrolytic Capacitor”, Japanese Patent Application Laid-Open No. 7-211161, “Device for Manufacturing Lead Wire for Electrolytic Capacitor”, or the like is used for manufacturing this lead wire 102.
[0004]
[Problems to be solved by the invention]
By the way, a wire rod such as a copper wire or a soft iron wire is used for the external lead 108. When such a wire rod is sheared, for example, as shown in FIGS. However, there are cases where a large number of sharp burrs 118 are generated at the tip due to the stickiness of the wire, the shape of the cutter edge, or the like. When the sharp-angled tip portion 116 having such a burr 118 is pressed against the end surface 114 of the element-side lead 106 as indicated by an arrow X in FIG. 7, the element-side lead 106 exists because the burr 118 exists. There is a possibility that the bite into the deeper (external lead 108a) or a shift in the bite direction (external lead 108b).
[0005]
It is extremely difficult to correct these. If the bite is deep, considerable force is required to separate the external lead 108 and the element-side lead 106 during welding. If the bit is forcibly separated, vibration will occur in the external lead 108 and in the biting direction. Even when the deviation occurs, the external lead 108 is vibrated at the time of separation. As a result, the external lead 108 is welded to the element-side lead 106 in a state where twisting or bending occurs. As a result, the welded portion 110 between the external lead 108 and the element-side lead 106 is disadvantageous in that the weld strength and weld quality are lowered and the stability is lacking. If such a lead wire 102 is used, the reliability of the electrolytic capacitor may be reduced.
[0006]
By the way, for example, Japanese Utility Model Laid-Open No. 52-167546 “Electrode Terminals in Electrolytic Capacitors” is known as a method for manufacturing such a lead wire. In this electrode terminal, by forming a recess or a protrusion in the middle of the inclined surface on the tip end side of the external lead connected to the aluminum material that is the element side lead, the molten aluminum material is bitten into the uneven portion and the element This prevents separation of the external leads from the side leads. Even if the concavo-convex part is formed on such an inclined surface, if the burr is generated at the tip part, as shown in FIG. 8, the biting of the external lead into the element side lead cannot be suppressed, and the Misalignment cannot be prevented. For this reason, even if an electrode terminal having a shape according to Japanese Utility Model Laid-Open No. 52-167546 is used for the external lead, there is a disadvantage in that the welding strength and the welding quality are still lowered and the stability is insufficient, and the reliability of the electrolytic capacitor is reduced. May decrease.
[0007]
Accordingly, an object of the present invention is to provide a method for manufacturing a lead wire for an electrolytic capacitor that prevents deterioration in welding strength and welding quality and has high stability.
[0008]
[Means for Solving the Problems]
The configuration of the electrolytic capacitor lead manufacturing method according to the present invention that solves such a problem is listed below with the reference numerals used in the embodiments.
[0009]
According to a first aspect of the present invention, there is provided a method for producing an electrolytic capacitor lead wire comprising: an electrolytic capacitor lead wire formed by welding an element side lead (38) connected to an electrolytic capacitor element and an external lead (2). In the manufacturing method, a sharpened portion (28, 30) and a flat portion (recessed portion 26) from which burrs are removed are formed at the distal end portion of the external lead, and the sharpened portion is formed on a flat welding surface on the element side lead side. While colliding and biting, the amount of biting is limited at the flat portion, and a welding current is passed between both the external lead and the element side lead, and the external lead and the element side lead are separated from each other to arc the to generate, and the element-side lead and the external lead causes partially melted, to characterized in that to weld by abutting and the element-side lead and the external lead .
[0010]
The method for manufacturing a lead wire for an electrolytic capacitor according to a second aspect of the present invention is characterized in that the sharp portion is formed of a plurality having a distance equal to or smaller than the diameter of the external lead.
[0011]
According to a third aspect of the present invention, there is provided a method of manufacturing a lead wire for an electrolytic capacitor, wherein the external lead is cut to form an acute tip portion (10), and the central portion of the sharp tip portion is formed. A flat portion (concave portion 26) formed of a concave portion is formed on the surface, and the sharp portion is formed with the concave portion interposed therebetween.
[0013]
According to a fourth aspect of the present invention, there is provided a method for producing a lead wire for an electrolytic capacitor, wherein the element-side lead is formed of the same metal as an electrode material of the electrolytic capacitor element.
[0014]
According to such a configuration, since a sharp portion is formed at a specific location at the tip of the external lead, it is possible to avoid the influence of conventional unspecified burrs and realize a stable welding process with the element side lead. In addition, since the flat portion is formed at the tip of the external lead, the contact and separation with the element side lead can be controlled, thereby realizing a stable welding process between the external lead and the element side lead. Thus, it is possible to avoid a decrease in welding strength and welding quality and to contribute to improving the reliability of the electrolytic capacitor.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show an embodiment of a method of manufacturing a lead wire for an electrolytic capacitor according to the present invention, FIG. 1 shows a cutting process of an external lead, FIG. 2 shows a molding process thereof, and FIG. 3 shows a welding process thereof. ing.
[0016]
As shown in FIG. 1A, for example, a round bar-shaped wire 4 is used as a material of the external lead 2, and the surface of a soft iron wire having a diameter of about 0.3 to 1.2 mm is used for the wire 4 for example. A copper film is used. The wire 4 may be a soft copper wire, a soft copper wire, or another metal wire. The wire 4 is formed and cut by shearing with the cutting edge sides of the two shearing blades 6 and 8 being advanced and retracted in opposite directions (arrow a and b directions). Each of the shearing blades 6 and 8 has a blade edge angle θ and a width W corresponding to the shape of the tip of the external lead 2. By this shearing process, an acute-angled tip portion 10 is formed at the tip portion of the external lead 2 as shown in FIG. 1B. In this embodiment, the acute angle is formed by two inclined surfaces 12 that are line-symmetric. A shaped tip 10 is formed. That is, in this shearing process, the cutting and molding of the external lead 2 are performed simultaneously, but the cutting of the wire 4 and the molding process of the acute-angled tip portion 10 may be performed separately. The other end of the external lead 2 is formed to a predetermined length by cutting off.
[0017]
Then, as shown in FIG. 2C, the sharp tip portion 10 of the external lead 2 is molded. A molding die 14 is used as the molding means, and the molding die 14 has, for example, a V-shaped first and second molding surfaces 16 and 18 and a third parabolic or semicircular cross section. A molding surface 20 is formed. The top of the molding surface 20 is formed as a flat surface.
[0018]
Therefore, the external lead 2 is held by a holding means (not shown), and the molding die 14 is, for example, in the direction indicated by the arrow c so that the acute tip 10 is bridged between the molding surfaces 16 and 18 of the molding die 14. 2 and the molding surfaces 16 and 18 of the molding die 14 are pressed against the acute tip portion 10 of the external lead 2, the acute tip portion 10 is deformed by the molding die 14 (D) and (E) in FIG. ). That is, the acute-angled tip portion 10 of the external lead 2 has a paraboloid corresponding to the triangular inclined surfaces 22 and 24 and the molding surface 20 by the molding surfaces 16 and 18 at the tip-side corner portion of the inclined surface 12 generated during shearing. A concave portion 26 having a surface is formed, and as a result, a pair of sharp portions 28 and 30 are formed in this embodiment as a plurality of sharp portions with the concave portion 26 interposed therebetween. The innermost surface of the recess 26 is a flat surface. Further, the distance d between the sharp portions 28 and 30 is formed to be narrower than the diameter R of the wire 4 forming the external lead 2, and the distance between the bottom surface of the concave portion 26 and the tips of the sharp portions 28 and 30 is, for example, 3 μm. Set to degree. When such a forming process is performed, the burrs 32 {(C) in FIG. 2} generated in the sharp tip portion 10 of the external lead 2 by the shearing process are formed by the forming surfaces 16, 18 and 20, or by the forming. Will be removed.
[0019]
Then, as shown in FIG. 3 (F), for example, a wire made of the same metal material as the electrode material of the capacitor element, for example, a round bar-shaped aluminum wire having a diameter of about 1 to 3 mm is formed and processed into a flat portion. 34 and a non-flat portion 36 having an outer shape of a round bar-like wire rod are formed, and a flat end face 40 as a welding surface is formed on the non-flat portion 36 side of the element-side lead 38. Is formed. Then, the end face 40 of the element side lead 38 is disposed, and the external lead 2 is held by the movable chuck 42 so that the sharp portions 28 and 30 are opposed to each other at regular intervals. In this case, an arc welding device 44 is connected between the element side lead 38 and the external lead 2.
[0020]
Next, as shown in FIG. 3G, the external lead 2 is held by the movable chuck 42 and moved in the direction indicated by the arrow e, and the sharpened portions 28 and 30 thereof are predetermined on the end face 40 of the element side lead 38. When it is made to collide with the position and bite into the end surface 40, the innermost surface of the recess 26 functions as a stopper. In this state, when the welding apparatus 44 connected between the external lead 2 and the element side lead 38 is operated, a welding current flows between the external lead 2 and the element side lead 38, and the external lead 2 and the element side lead 38. An arc welding current starts to flow between the contact point with the side lead 38, that is, between the sharp portions 28 and 30 of the external lead 2 and the end face 40 of the element side lead 38.
[0021]
From the start of the welding current flow, the sharpened portions 28 and 30 of the external lead 2 are moved away from the end surface 40 of the element-side lead 38 in the direction indicated by the arrow f as shown in FIG. When the distance m is set between them, an arc is generated between the sharp portions 28 and 30 of the external lead 2 and the end surface 40 of the element side lead 38, and both the external lead 2 and the element side lead 38 facing each other are partially formed. To melt.
[0022]
In this state, when the external lead 2 is moved to the end face 40 side of the element side lead 38 and brought into contact, fusion between the molten metals occurs, and the external lead 2 and the end face 40 of the element side lead 38 are welded. The molten metal is spheroidized by surface tension, a hemispherical weld 46 is formed, and a lead wire 48 in which the external lead 2 and the element side lead 38 are integrated is formed as shown in FIG. The In this case, the welded portion 46 forms an alloy layer by the fusion of the metal constituting the external lead 2 and the metal constituting the element side lead 38.
[0023]
Then, the lead wire 48 is connected to a cathode foil and an anode foil (not shown) to form a capacitor element, which is then housed in an exterior case, and the opening is sealed with a sealing member, thereby forming an electrolytic capacitor. it can.
[0024]
In such welding of the external lead 2 and the element side lead 38, in this embodiment, the sharp portions 28 and 30 of the external lead 2 and the end surface 40 of the element side lead 38 are brought into contact with each other. Since the bottom surface of the recess 26 formed between the sharp portions 28 and 30, that is, the flat surface formed at the innermost surface functions as a stopper, the amount of biting is limited and becomes constant. . In addition, since the shape of each of the sharp portions 28 and 30 is constant, if the applied pressure is constant, the depth of biting into the element side lead 38 does not change, and the external lead 2 from the element side lead 38 does not change. When the gaps are separated from each other, mechanical fluctuations such as vibration of the external lead 2 are not caused, and welding can be stabilized.
[0025]
In the case of this embodiment, both the sharp portions 28 and 30 of the acute-angled tip portion 10 of the external lead 2 bite into the end surface 40 of the element side lead 38, so that the biting direction is regulated by the sharp portions 28 and 30. As a result, the direction deviation of the external lead 2 with respect to the element side lead 38 can be prevented, and as a result, a stable welding current can flow. In addition, the arc generated when the two are separated from each other is generated at each of the sharp portions 28 and 30, and can be concentrated on each of the sharp portions 28 and 30 to melt the element side lead 38 and the external lead 2 within a certain range. , Stable welding can be performed.
[0026]
In the first embodiment, the formation interval of the sharp portions 28 and 30 is formed to be narrower than the diameter R of the wire 4. For example, as shown in FIGS. It is also possible to form a recess 26 having an arcuate ridge line in the interval between the sharp portions 28 and 30 and to obtain the same effect as in the first embodiment. Can do.
[0027]
Further, for example, as shown in FIGS. 5A and 5B, the welded surface side of the external lead 2 is a flat end surface 50, and a plurality of conical sharpened portions 52 are formed in the end surface 50. May be. In this case, the interval d between the sharp portions 52 is set smaller than the diameter R of the wire 4 that forms the external lead 2. Even with such a configuration, it is possible to prevent the deviation in the biting direction due to the three-point biting into the element side lead 38.
[0028]
Further, in the embodiment, the case where two or three sharp portions are formed has been described as an example. The effect of can be obtained.
[0029]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
a It is possible to manufacture a lead wire for an electrolytic capacitor having high stability by preventing a decrease in welding strength and welding quality.
b Since a sharp portion is formed at a specific location on the distal end side of the external lead, the influence can be avoided by removing or molding unspecified burrs, and a flat portion is formed at the distal end portion of the external lead. Therefore, it is possible to control the contact and separation with the element side lead, thereby realizing a stable welding process between the external lead and the element side lead, avoiding a decrease in welding strength and welding quality, and the reliability of the electrolytic capacitor It can contribute to improvement.
[Brief description of the drawings]
FIG. 1 is a diagram showing a cutting process of external leads, which is a first embodiment of a method for producing a lead wire for an electrolytic capacitor according to the present invention.
FIGS. 2A and 2B show a forming process of an external lead, FIG. 2C is a view showing the forming process, FIG. 2D is a plan view showing a first embodiment of the formed external lead, and FIG. It is a front view.
FIG. 3 shows a welding process between an external lead and an element side lead, (F) shows an initial arrangement, (G) shows a welding start, (H) shows a welding process, (I) FIG. 4 is a view showing a lead wire formed by welding.
4A and 4B show a second embodiment of an external lead, in which FIG. 4A is a plan view thereof and FIG. 4B is a front view thereof.
5A and 5B show a third embodiment of an external lead, wherein FIG. 5A is a plan view thereof and FIG. 5B is a front view thereof.
FIG. 6 is a perspective view showing a form of a general lead wire for an electrolytic capacitor.
FIG. 7 is a diagram showing a welding process between a conventional external lead and an element side lead.
8A and 8B show a conventional external lead, FIG. 8A is a side view thereof, and FIG. 8B is a plan view thereof.
[Explanation of symbols]
2 External lead 4 Wire material 10 Sharp tip portion 26 Recessed portion (flat portion)
28, 30 Sharp point 38 Element side lead 40 End face (welded face)
48 Lead wire 50 End face 52 Sharp part

Claims (4)

A method for producing a lead wire for an electrolytic capacitor formed by welding an element-side lead connected to an electrolytic capacitor element and an external lead,
A sharpened portion and a flat portion are formed by removing burrs at the distal end portion of the external lead, and the sharpened portion is caused to collide with a flat welding surface on the element side lead side, and the amount of biting is reduced by the flat portion. limited to, the by generating arc spaced apart and said element-side lead and the external lead together with flow external leads and the two welding current between the said element side lead, and the element-side lead and the external lead A method for producing a lead wire for an electrolytic capacitor , wherein the external lead and the element side lead are welded while being partially melted .
Sensor wire manufacturing method.   2. The method of manufacturing a lead wire for an electrolytic capacitor according to claim 1, wherein the sharp portion is composed of a plurality of pieces having an interval equal to or narrower than the diameter of the external lead.   In the external lead, a wire rod is cut to form an acute tip portion, and a flat portion including a recess is formed at the center of the acute tip portion, and the sharp portion is formed with the recess interposed therebetween. The method for manufacturing a lead wire for an electrolytic capacitor according to claim 2, wherein the lead wire is used.   2. The method of manufacturing a lead wire for an electrolytic capacitor according to claim 1, wherein the element-side lead is formed of the same metal as an electrode material of the electrolytic capacitor element.

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