JP4923377B2 - battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery using a grid body in which bars are connected in a net shape as an electrode plate.
[0002]
[Prior art]
The lattice used for the electrode plate of a lead storage battery may be produced by expanding (developing). As shown in FIG. 4, the rotary method, which is one of the methods for manufacturing a lattice body by using this expand, first passes between the upper and lower disk cutter rolls 2 while conveying the lead sheet 1 in the longitudinal direction. In this lead sheet 1, a large number of slits 1a are formed in a staggered manner, and then the lead sheet 1 is expanded in the width direction and expanded to produce a lattice body in which a large number of bars 1b are connected in a net shape. is there.
[0003]
Each of the slits 1a is obtained by separating the lead sheets 1 in a zigzag manner for each step in the width direction by the disk cutters of the upper and lower disk cutter rolls 2, and between the adjacent slits 1a in the width direction. Each becomes a cross 1b. A plurality of bars 1b formed between the slit 1a intermittently continuous in the conveying direction of the lead sheet 1 and the slit 1a adjacent thereto in the width direction are on the same stage. In addition, in the example shown in FIG. 4, the crosspiece 1b is formed in the center part of the width direction of the lead sheet 1 so that it may not form the crosspiece 1b over both sides, respectively.
[0004]
The lead sheet 1 is developed by the chain unfolding devices 3 and 3. The chain unfolding devices 3 and 3 are arranged in an eight-letter shape on both sides in the width direction of the lead sheet 1 and spaced apart toward the downstream side in the transport direction, and sequentially lock both ends of the lead sheet 1 being transported. By doing so, this lead sheet 1 is expanded in the width direction, that is, the direction in which the space between the steps widens. Therefore, in the lead sheet 1, when the space between the slits 1a spreads in the width direction, the crosspieces 1b of each step are bent in a zigzag shape, and connected as a net as a whole.
[0005]
The lead sheet 1 developed in this way is cut at predetermined intervals along the conveying direction, and is also divided into two in the width direction to form current collecting ears in the divided central portion. Thus, a lattice body is obtained. Then, positive and negative electrode plates are formed by filling the active material between the grid-like bars 1b of each grid, and a lead storage battery is formed by storing these electrode plates in a battery case and injecting an electrolyte.
[0006]
Here, in the electrode plate of the lead storage battery, only the filled active material is involved in charging / discharging. Therefore, the smaller the cross-sectional area of the crosspiece 1b, the smaller the volume (weight) of the grid body occupied in the electrode plate. Battery capacity (weight) density can be increased. However, even though the electrode plate of the lead storage battery collects current through the grid bars 1b, the cross section of the bars 1b is too small because corrosion due to the electrolytic solution proceeds with charge / discharge. This corrosion may further reduce the cross-sectional area and increase the electrical resistance or cause crossing. When the crosspiece 1b breaks out or the battery resistance increases in this way, current collection from a position farther from the ear that collects the current than the crosspiece 1b is obstructed, and charging / discharging As a result, the active material involved in the battery is reduced, so that the battery capacity is lowered and the battery life is shortened.
[0007]
Therefore, the cross-sectional area of the crosspieces 1b formed at the steps on both ends in the width direction of the lead sheet 1 is made smaller so that the capacity density of the battery can be increased without significantly hindering current collection. The invention has been made conventionally (see, for example, Patent Document 1). In the present invention, the crosspiece 1b in the central portion in the width direction of the lead sheet 1 has a large cross-sectional area, so that the capacity density of the battery is not increased. By reducing the area, the capacity density of the battery can be increased. Moreover, since the grid is close to the current collecting ears, the central crosspiece 1b, which is likely to interfere with current collection due to a crosspiece or the like, has a large cross-sectional area and is not easily affected by corrosion. However, even if the crosspieces 1b at both ends in the width direction are cut off due to corrosion, they are far from the ears, so that the amount of the active material filled at a position farther than the crosspieces 1b is small. As a result, current collection is hardly inhibited.
[0008]
In addition, an invention in which the cross-sectional area of the crosspiece 1b formed in the steps on both ends in the width direction of the lead sheet 1 has been conventionally made (see, for example, Patent Document 2). In the present invention, the crosspieces 1b formed at the steps on both ends in the width direction are more likely to be broken due to tensile stress or the like when the lead sheet 1 is deployed. It is made larger to increase the mechanical strength.
[0009]
[Patent Document 1]
JP 58-209066 A (Claim 2)
[Patent Document 2]
JP 2002-117861 A (Claim 2)
[0010]
[Problems to be solved by the invention]
However, as described above, when the cross-sectional area of the crosspiece 1b of the lattice body is changed according to the level, conventionally, the number of steps with the same cross-sectional area of the crosspiece 1b is increased as much as possible, so that it is roughly changed stepwise. In other words, there was a portion where the cross-sectional area suddenly changed between adjacent steps. In this way, the number of steps having the same cross-sectional area of the crosspiece 1b is increased, for example, in the case of the rotary system, it is possible to achieve common parts by using a large number of disc cutters having the same thickness. This is because it is not necessary to prepare many kinds of disc cutters having different thicknesses. However, if the cross-sectional area of the crosspiece 1b changes abruptly between the steps in this way, when the lead sheet 1 is deployed, tensile stress concentrates on the crosspiece 1b of the step where the cross-sectional area changes abruptly, resulting in a crosspiece or crack. The problem that it becomes easy occurs. In particular, when the cross-sectional area of the crosspieces is greatly changed by more than 10% only at one stage or only between a few stages, the crosspieces or cracks are formed on the crosspiece 1b. Often it tends to occur.
[0011]
The present invention has been made in order to cope with such a situation. By setting the ratio of the change in the cross-sectional area of the crosspieces of the lattice in the range of 90% or more and 110% or less, the crosspieces and cracks at the time of deployment can be obtained. An object of the present invention is to provide a battery using a grid that hardly occurs as an electrode plate.
[0012]
[Means for Solving the Problems]
In the invention of claim 1, the metal sheet is staggered for each step by rotary expansion so that the upper frame portion of the lattice body is formed at the center and the lower frame portion of the lattice body is formed at both ends. In a battery using a grid body that is formed by separating and forming the crosspieces and expanding in the direction in which the steps spread, the crosspieces of the crosspieces of each step being 0.30 mm ² or more, 1. Within the range of 60 mm ² or less, the cross-sectional area and the crosspieces of the crosspieces excluding the crosspieces at the most ends connected to the upper and lower forehead parts and the crosspieces connected to the crosspieces at both ends are adjacent to the cross section. It is characterized in that it is changed for each step or more so that the ratio of the cross-sectional area of the step crosspieces is in the range of 90% to 110%.
[0013]
According to the present invention, the cross-sectional area of each bar of the grid body is 0.30 mm ² or more at a minimum, in the range of 1.60 mm ² or less at maximum, it as or become extremely small becomes or larger In addition, there is no change in cross-sectional area of the crosspieces between the steps of the grid body within 10%. Can be prevented. When the cross-sectional area of the crosspiece is less than 0.30 mm ² , the crosspiece becomes too thin, and crosspieces frequently occur during deployment regardless of the size of the cross-sectional area of the crosspieces at other stages. On the other hand, when the cross-sectional area of the crosspiece exceeds 1.60 mm ² , the capacity density of the battery is too low because the crosspiece 1b is too thick. If the cross-sectional area of the crosspieces changes every stage, the cross-sectional areas of all adjacent crosspieces will be different, and the ratio of the cross-sectional areas of all these crosspieces will be within the range of 100 ± 10%. Become. Also, when the cross-sectional area of the crosspiece changes every two or more stages, even if the cross-sectional area of the crosspieces is equal to 100% and the cross-sectional area of this crosspiece changes even if two or more stages are continuous. The ratio of the cross-sectional areas of these adjacent steps is within a range of 100 ± 10%. The ratio of the cross-sectional areas of the crosspieces may change for each stage in some stages, and may change for every two or more stages in other stages. In addition, the cross-sectional area of the crosspiece is normally a monotonous change that gradually decreases or increases along the step arrangement direction. For example, the cross-sectional area that has gradually decreased is increased only at the end. It may change to.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
FIG. 1 shows an embodiment of the present invention and is a partial plan view of a developed lead sheet manufactured by a rotary method. In addition, the same number is attached | subjected to the structural member which has the function similar to the prior art example shown in FIG.
[0016]
In the present embodiment, as in the conventional example, a lead storage battery using a grid body produced by a rotary method as an electrode plate will be described. Therefore, as shown in FIG. 4, the grid body of the electrode plate of the lead storage battery first passes the lead sheet 1 between the upper and lower disk cutter rolls 2 while conveying the lead sheet 1 in the longitudinal direction. A large number of slits 1a are formed in a staggered pattern in 1 and then the lead sheet 1 is expanded and expanded in the width direction, whereby a large number of bars 1b are connected in a net shape.
[0017]
As shown in FIG. 1, the lattice body is manufactured such that the crosspiece width W _i (i is the number of stages of 1 to 12) of the crosspiece 1 b of each stage changes according to the stage. In the present embodiment, since the sheet thickness using a uniform lead sheet 1, the cross-sectional area of the crosspiece 1b of each stage becomes these桟幅W _i and the sheet thickness Metropolitan product of lead sheet 1, the respective stages also it changed the cross-sectional area in proportion to the change in桟幅W _i of the crosspiece 1b. However, these cross-sectional area of the crosspiece 1b of each stage, minimum 0.30 mm ² or more are also limits such that 1.60 mm ² within the range at the maximum. When the cross-sectional area of the crosspiece 1b is less than 0.30 mm ² , the crosspiece 1b becomes too thin, so that the crosspieces frequently break due to the stress at the time of deployment regardless of the size of the cross-sectional area of the crosspiece 1b at the other stage. Because it becomes like this. Further, when the cross-sectional area of the crosspiece 1b exceeds 1.60 mm ^2, even if only if crosspiece 1b of some stages, because too large a crosspiece 1b, also the crosspiece 1b of the other stages though somewhat thinner This is because the capacity density of the battery is too low. Moreover, such a thick beam 1b is not affected by the size of the cross-sectional area of the beam 1b at the other stage, so that the beam is not easily cut or cracked.
[0018]
Here, the step of the grid body generally refers to an arrangement in which the crosspieces 1b before development are arranged in almost one row in a direction substantially orthogonal to the development direction. The steps of the crosspiece 1b are formed over a number of steps in the developing direction, that is, in the width direction. In addition, the grid used for the electrode plate is formed by connecting a plurality of crosspieces 1b in a net-like manner from the upper part to the lower part between the upper part of the upper frame and the lower part of the lower part. Ears for current collection project from the section further upward. And since the lead sheet 1 of this embodiment forms the ear | edge for current collection in a center part and cuts out a grid body, this center part becomes an upper frame part of each grid body, and both ends serve as a lower frame part. The crosspieces 1b are formed symmetrically over a number of stages from the central portion, which is the upper frame portion, to both ends.
[0019]
桟幅W _i crosspiece 1b of each stage is formed so thin approximately every two steps over the桟幅W ₁ of the central portion to桟幅W ₁₁ at both ends, the invention of Patent Document 1 by which In the same manner as described above, the capacity density of the electrode plate is increased. However,桟幅W ₁₂ of crosspiece 1b of the most both ends stages leading to the lower frame part is formed as to tensile stress during expansion is applied initially increased, is slightly thicker than桟幅W ₁₁ of the inner Thus, the crossing of the lower forehead is prevented. Thus in order to change the桟幅W _i crosspiece 1b of each stage, it is sufficient to vary the thickness of each disc cutter disc cutter roll 2 shown in FIG.
[0020]
Moreover, the cross-sectional area of the crosspiece 1b of each step is within the range of 90% or more and 110% or less with respect to the cross-sectional area of the adjacent crosspiece 1b. That is, the cross-sectional area of the crosspiece 1b of each stage is proportional to桟幅_{W i} of the crosspiece 1b, the ratio of桟幅_{W i} for all the adjacent stages, i.e. _{W j / W j + 1 (} j = 1~ 11) and W _k / W _k-1 (k = 2 to 12) are both in the range of 0.9 to 1.1. In the case of the present embodiment, the width W _{i of the} crosspiece 1b becomes narrower from the upper forehead to the lower forehead because the second to third, fourth to fifth, sixth to seventh, and eighth steps. a ninth stage from stage, since become thick is a 12 stage from 11 _stage, W 2 / _{W 3} and _W 4 / _{W 5} and _W 6 / _{W 7} and _W 8 / _{W 9} and _W 11 / W ₁₂ and their reciprocals are all in the range of 0.9 to 1.1, and are almost 1.0 between all other stages.
[0021]
According to the above configuration, since the change in the cross-sectional area of the crosspiece 1b between the steps of the lattice body is within 10%, this cross-sectional area does not change suddenly between specific steps, and the expansion It gradually increases or decreases at each step in the direction (width direction). Accordingly, since stress is not particularly concentrated on the cross-section 1b at the time of deployment, it is possible to prevent cross-cuts or cracks from occurring on the cross-section 1b. In addition to reducing manufacturing defects during the production of the body, it is possible to improve the life performance of a lead storage battery using this grid body as an electrode plate.
[0022]
In the above embodiment, since the lead sheet 1 having a uniform sheet thickness is used, the cross-sectional area is changed by changing the crosspiece width of the crosspiece 1b. However, when the lead sheet 1 having a different sheet thickness is used. The cross-sectional area can be changed without changing the crosspiece width of the crosspiece 1b. For example, by using a lead sheet 1 that is thickest at the center in the width direction and becomes thinner toward both ends, and the edges of both ends are slightly thickened again, The cross-sectional area of the crosspiece 1b can be changed according to the step as in the above embodiment. However, the cross-sectional area of the crosspiece 1b may be changed by changing the sheet thickness of the lead sheet 1 and also changing the crosspiece width of the crosspiece 1b. When the sheet thickness of the lead sheet 1 changes only in the width direction, the cross-sectional area of each crosspiece 1b is substantially constant in any part in the lengthwise direction of the crosspiece 1b. ), However, the cross-sectional area of each crosspiece 1b is not constant. Also, when the slits 1a for separating the bars 1b are slightly inclined without being completely along the longitudinal direction, and the width of the bars is different in the length direction of the bars 1b, The cross-sectional area of 1b is not constant. However, since the change in the cross-sectional area of the crosspiece 1b is slight, the average value of these cross-sectional areas is taken as the cross-sectional area of the crosspiece 1b.
[0023]
Moreover, in the said embodiment, although the cross-sectional area of the crosspiece 1b of each step was changed about every two steps, if the change of this cross-sectional area is in the range which does not exceed 10%, every more steps. It can be changed, and conversely, it can be changed for each stage. In the case where the sheet thickness of the lead sheet 1 changes gradually instead of every step, the cross-sectional area changes every step if the crosspiece 1b has a uniform crosspiece width. However, when the cross-sectional area is changed by changing the cross-piece width of the cross-piece 1b, one set of disc cutters having the same thickness is formed by the upper and lower disc cutter rolls 2 by changing the cross-sectional area every two steps. Can be used one by one (actually, the disk cutters of the same thickness are used on both sides because they are symmetrical at the center). It becomes necessary to use disc cutters having different thicknesses, and the types of disc cutters to be used increase.
[0025]
Moreover, in the said embodiment, although the lead storage battery using the grid body which produced the lead sheet 1 by the rotary type expansion process for an electrode plate was demonstrated, if it is a battery which uses the grid body produced in this way for an electrode plate, other This type of battery can also be implemented in the same manner, and a lattice body can be produced using a metal sheet other than the lead sheet 1.
[0026]
【Example】
The cross-sectional area ratio of the crosspiece 1b is compared based on FIGS. 2 and 3 for the lattice bodies of the conventional example and the example. In the lattices of the conventional example and the example, the crosspieces 1b are formed in 21 steps. As in the above embodiment, the cross-sectional area of the crosspiece 1b closest to the upper frame is maximized, and as the lower frame is approached, every step or more Fig. 5 shows a lattice body in which the cross-sectional area is reduced and only the cross-sectional area of the crosspiece 1b closest to the lower frame is slightly increased.
[0027]
2 and 3, the change in the cross-sectional area of the crosspiece 1b of each stage of the lattice body in the above-described conventional example and the embodiment is expressed as "the ratio to the maximum cross-sectional area" (indicated by a thin broken line), that is, closest to the upper forehead. The ratio (%) of the cross-sectional area of the crosspiece 1b at each step when the cross-sectional area of the crosspiece 1b is 100% and the "ratio of the cross-sectional area of adjacent steps" (indicated by a thick solid line), that is, adjacent to the upper forehead The ratio (%) of the cross-sectional area of the crosspiece 1b at each stage when the cross-sectional area of the crosspiece 1b is 100% is shown.
[0028]
The ratio of the grid body of the conventional example to the maximum cross-sectional area of each crosspiece 1b is 10% over the three steps of the cross-sectional area of each crosspiece 1b from the upper forehead side, as shown by the thin broken line in FIG. The cross-sectional area of the crosspiece 1b closest to the lower forehead is increased by more than 10%. Moreover, the cross-sectional area of each crosspiece 1b is made equal to the minimum size over the 10th to 20th stages. Therefore, the “ratio of cross-sectional areas of adjacent steps” of each crosspiece 1b is lower than 90% in all the steps where the cross-sectional area changes, as indicated by the thick solid line in FIG. It drops to nearly 85% at the eye 1b. Further, the 21st-stage crosspiece 1b closest to the lower forehead greatly changes to about 117%.
[0029]
On the other hand, the “ratio to the maximum cross-sectional area” of each crosspiece 1b of the grid body of the embodiment is as follows. As shown by the thin broken line in FIG. In addition, the width is reduced by about 5% over four steps, then is reduced by about 5% over two steps every four steps, and the cross-sectional area of the crosspiece 1b closest to the lower frame is increased by about 4%. Further, the 17th to 20th stages having the smallest cross-sectional area of the crosspiece 1b are only four stages. Therefore, the “ratio of the cross-sectional area of the adjacent steps” of each crosspiece 1b is slightly less than 95% in most of the steps where the cross-sectional area changes, as indicated by the thick solid line in FIG. Even the large 13th crosspiece 1b is reduced only to about 93%. Moreover, the 21st-stage crosspiece 1b closest to the lower frame also changes only to about 106%.
[0030]
As a result, in the lattice body of the conventional example, the ratio of the cross-sectional area of the crosspiece 1b of each stage to the cross-sectional area of the crosspiece 1b of the adjacent stage is 90% or more and 110% in all stages where the cross-sectional area changes. % Range (area indicated by dot hatching in FIG. 2), and for this reason, the crosspieces 1b are liable to be cut off or cracked during development. However, in the lattice body of the example, the ratio of the cross-sectional area of the crosspiece 1b at each stage to the cross-sectional area of the crosspiece 1b at the adjacent stage is in the range of 90% to 110% at any stage (FIG. 3). This is within the area indicated by dot hatching), which makes it difficult for crosspieces and cracks to occur in the crosspieces 1b during development.
[0031]
【Effect of the invention】
As is clear from the above description, according to the battery of the present invention, the change in the cross-sectional area of the crosspieces between the steps of the grid used for the electrode plate is within 10%. In the process, stress is not particularly concentrated on the crosspiece at a specific stage, and it is possible to prevent the occurrence of crosspieces and cracks and to eliminate the decrease in yield and battery life performance due to manufacturing defects. Become.
[Brief description of the drawings]
FIG. 1 is a partial plan view of a developed lead sheet produced by a rotary method according to an embodiment of the present invention.
FIG. 2 is a graph showing a conventional example and showing a change in cross-sectional area of a crosspiece at each stage of a lattice.
FIG. 3 is a graph showing an embodiment and showing a change in cross-sectional area of a crosspiece at each stage of the lattice body.
FIG. 4 is a plan view for explaining a method of manufacturing a lattice body by a rotary method.
[Explanation of symbols]
1 Lead sheet 1b pier W _{1 to} W ₁₂ Width

Claims (1)

A metal sheet is formed in a zigzag manner for each stage by rotary expansion so that the upper frame part of the grid is formed at the center and the lower frame part of the grid is formed at both ends , and a crosspiece is formed . in cells each crosspiece was used to plate a grid obtained by connecting the network by developing in a direction between the stage spreads, the cross-sectional area of the respective stages bars is 0.30 mm ² or more, 1.60 mm ² or less in the range The cross-sectional area of the crosspieces of the steps and the crosspieces of the steps adjacent to the crosspieces excluding the crosspieces of the steps connected to the upper and lower foreheads and the crosspieces connected to the crosspieces of both ends The battery is characterized in that it is changed for each stage or more so that the ratio of the ratio is in the range of 90% to 110%.

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