JP2012018760A - Manganese dry battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manganese dry battery having excellent discharge performance.SOLUTION: A manganese dry battery is constructed by storing a positive electrode mixture 1 via a separator 3 inside a bottomed cylindrical negative electrode zinc can 4 and by fitting for electrical contact a carbon rod 2 press-fitted in the vicinity of the center of the positive electrode mixture 1 on the inside of a substantially columnar protrusion 11a of a positive electrode terminal 11. In this manganese dry battery, providing a convex part 11c on a lateral face 11b of the inside of the protrusion 11a allows the use of a thinner carbon rod 2 as compared with conventional carbon rods; correspondingly, it allows the filling of more active material, which leads to the improvement of discharge performance.

Description

  The present invention relates to a manganese dry battery, and more particularly to a connection between a positive electrode terminal of a manganese dry battery and a positive electrode current collector.

  Conventionally, the connection between the positive electrode terminal and the positive electrode current collector in this type of battery is made near the center of the positive electrode mixture using manganese dioxide housed in a bottomed cylindrical negative electrode zinc can through a separator as an active material. Generally, a carbon rod (corresponding to a positive electrode current collector) is press-fitted, and the periphery of the end face is fitted into the inside of a substantially cylindrical protrusion of the positive electrode terminal to extract electricity to the outside. (See Patent Document 1).

Japanese Utility Model Publication No. 54-5029

  From the viewpoint of increasing the capacity of the battery, it is preferable that the carbon rod is as thin as possible within a range where the current collecting effect can be secured. However, the diameter of the carbon rod has heretofore been determined by the diameter of the protruding portion of the positive electrode terminal.

  This is because the minimum value of the diameter of the projecting portion of the positive electrode terminal is determined by the JIS standard or the IEC standard, and the diameter of the carbon rod fitted inside is naturally determined. For example, in the single type, the minimum value of the diameter of the protruding portion of the positive electrode terminal is 7.8 mm, and when the thickness of the positive electrode terminal is 0.2 mm, the diameter of the carbon rod is set to about 7.4 mm or more. It will be.

  That is, it is difficult to make the carbon rods thinner and to fill more active materials.

  In order to solve the above-mentioned object, the present invention accommodates a positive electrode mixture through a separator in a bottomed cylindrical negative electrode zinc can, and a carbon rod press-fitted in the vicinity of the center of the positive electrode mixture. In the manganese dry battery fitted inside and electrically in contact with the cylindrical protrusion, a protrusion is provided on the inner side surface of the protrusion.

  According to the present invention, it becomes possible to electrically contact a carbon rod thinner than the conventional one by the convex portion provided inside the substantially cylindrical protrusion of the positive electrode terminal, and the more the carbon rod is made thinner, the more active it is. The substance can be filled, and the effect of improving the discharge performance is achieved.

The front view which made a part of manganese dry battery of the present invention a section Sectional drawing which expanded between AA 'in FIG.

  According to the present invention, a positive electrode mixture is housed in a bottomed cylindrical negative electrode zinc can through a separator, and a carbon rod press-fitted near the center of the positive electrode mixture is inserted into a substantially cylindrical projection of the positive electrode terminal. In a manganese dry battery fitted inside and in electrical contact with each other, by providing a convex portion on the inner side surface of the projection, it becomes possible to make a carbon rod thinner than the conventional one in electrical contact. As a result, the active material can be filled more and the discharge performance can be improved.

  In a preferred embodiment, the convex portions are preferably arranged at equal intervals on the circumference on the side surface of the protrusion portion of the positive electrode terminal. If it does in this way, a carbon rod and a positive electrode terminal will contact with a good balance, and a favorable energization state can be secured. Specifically, it is preferable that two (180 ° interval) to six (60 ° interval) convex portions are arranged. The number is preferably 3 (120 ° intervals) or 4 (90 ° intervals).

  Moreover, the height of the said convex part is good to set it as the range of 0.1-1.6 mm. If it is lower than 0.1 mm, it is difficult to obtain a substantial improvement in discharge performance. On the other hand, when the height is larger than 1.6 mm, there is an increased possibility of opening a hole when forming the convex portion, and the processing becomes difficult.

  In addition, what is necessary is just to make the shape of the said convex part circular or square shape by planar view. It may be an alphanumeric character pattern expressing a company name, logo, product number, etc., or a combination thereof.

  Examples of the present invention will be described in detail below, but the present invention is not limited to the examples shown below.

  The AA manganese dry battery (R6) shown in FIG. 1 was produced by the following procedure. FIG. 1 is a front view, partly in section, of an AA manganese dry battery as one embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view taken along the line AA ′ in FIG.

  A piece of zinc alloy containing 0.01% by mass of lead, 0.0025% by mass of indium and 0.05% by mass of manganese was pressed to produce a cylindrical negative electrode zinc can 4 having an opening at one end.

  The positive electrode mixture 1 was accommodated in the negative electrode zinc can 4 through a separator 3 and a bottom paper 13 described later.

  The separator 3 was a kraft paper coated with a paste obtained by dispersing a cross-linked starch and a binder mainly composed of vinyl acetate in water and dried. At this time, the separator 3 was disposed so that the surface on which the paste material was applied was opposed to the negative electrode zinc can 4.

  The bottom paper 13 was formed by punching out 0.3 mm thick kraft paper into a circular shape and then squeezing it into a cup shape inside the separator 3.

  The positive electrode mixture 1 includes electrolytic manganese dioxide as an active material, acetylene black as a conductive material, an electrolytic solution containing 30% by mass of zinc chloride, 2% by mass of ammonium chloride, and 68% by mass of water, and zinc oxide as an additive. Was mixed with a mass ratio of 52.3: 8.7: 38.5: 0.5 (corresponding to a 5% increase over the conventional example described later). And the carbon rod 2 obtained by sintering carbon powder was inserted in the center part of the positive electrode mixture 1. The carbon rod 2 having a diameter of 3.0 mm was used.

  A hole for inserting the carbon rod 2 was provided in the center of the sealing body 5 made of polyethylene. Holes for inserting the carbon rods 2 were also provided in the paper 9 obtained by punching out the kraft paper in an annular shape. The carbon rods 2 were inserted into the holes of the paper 9 and the sealing body 5, respectively, and these were arranged on the upper part of the positive electrode mixture 1.

  The outer periphery of the negative electrode zinc can 4 was covered with a resin tube 8 made of a heat-shrinkable resin film for ensuring insulation. At that time, the upper surface of the resin tube 8 covered the upper surface of the outer periphery of the sealing body 5. Further, at the lower end portion, the negative electrode terminal 6 and a seal ring 7 are arranged on the outer surface side of the flat plate outer peripheral portion to cover the lower surface of the seal ring 7.

  The positive electrode terminal 11 was formed by pressing a tin plate having a thickness of 0.2 mm and having a cap-shaped protruding portion 11a and a flat plate-like collar portion (not shown) fitted to the upper end portion of the carbon rod 2. . In addition, the diameter of the protrusion part 11a was 4.3 mm, and the convex part 11c of 0.5 mm in height was provided in the side surface 11b so that it might become equal intervals of 120 degrees on the circumference. And this was fitted to the end face of the carbon rod 2 to electrically connect the positive electrode terminal 11 and the carbon rod 2.

  An insulating ring 12 made of resin is disposed on the flat collar portion of the positive electrode terminal 11.

  A metal outer can 10 made of a cylindrical tin plate is placed outside the resin tube 8, its lower end is bent inward, its upper end is curled inward, and its tip is insulated. The battery was obtained by caulking the ring 12.

(Conventional example)
The AA size is the same as that of the embodiment except that the diameter of the carbon rod 2 is 4.0 mm, the filling amount of the positive electrode mixture 1 is 8.9 g, and no protrusion is provided on the side surface 11 b of the protruding portion of the positive electrode terminal 11. A manganese dry battery (R6) was produced.

  Next, the evaluation and results of each battery obtained above will be described. As an evaluation of the discharge performance, a time required to reach 0.9 V was measured under a 20 ± 2 ° C. environment by applying a load of 3.9Ω per cell (load corresponding to a toy or a motor). The average value of each of the five batteries for each battery was 94 minutes for the battery of the conventional example, and lasted for 101 minutes for the battery of the example.

  From the above results, it is clear that the batteries of the examples according to the present invention have excellent discharge performance.

  Although the AA type has been described in the above-described embodiments, the present invention can of course be applied to other types (single 1, single 2, single 4, single 5).

  Since the manganese dry battery of the present invention is excellent in discharge performance, it can be suitably used for any device that uses a dry battery as a power source.

DESCRIPTION OF SYMBOLS 1 Positive electrode mixture 2 Carbon rod 3 Separator 4 Negative electrode zinc can 5 Sealing body 6 Negative electrode terminal 7 Seal ring 8 Resin tube 9 Paperboard 10 Metal exterior can 11 Positive electrode terminal 12 Insulation ring 13 Bottom paper

Claims (4)

  The positive electrode mixture is housed inside the bottomed cylindrical negative electrode zinc can through a separator, and the carbon rod press-fitted near the center of the positive electrode mixture is fitted inside the substantially cylindrical protrusion of the positive electrode terminal. A manganese dry battery brought into electrical contact, wherein a protrusion is provided on an inner side surface of the protrusion.   2. The manganese dry battery according to claim 1, wherein the protrusions are arranged at equal intervals on a circumference on a side surface of the protrusion of the positive electrode terminal.   The manganese dry battery according to claim 2, wherein the number of the convex portions is in a range of 2 to 6.   The manganese dry battery according to claim 1, wherein a height of the convex portion is in a range of 0.1 to 1.6 mm.

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