JP2013196828A - Cast grid body of lead-acid storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize a current flowing in a region surrounded by a frame member during charge and discharge.SOLUTION: Lateral grids 13, 23 of each cast grid body 11, 21 of a positive electrode plate and a negative electrode plate are configured so that the distance of adjoining lateral grids 13, 23 is shorter as separating from ear parts 16, 26. When configuring each lateral grid 13, 23 in such a manner, the total cross-sectional area in each divided region, obtained by dividing a region surrounded by frame members 12, 22 at regular intervals in the extension direction of longitudinal grids 14, 24, becomes larger as separating from the ear part 26.

Description

  The present invention relates to a cast grid of a lead storage battery.

2. Description of the Related Art Conventionally, an electrode plate used for a lead-acid battery is configured by holding an active material by a lattice body having protrusions called lattice portions and lattice-shaped cells (for example, Patent Document 1).
The lattice body includes a rectangular frame-shaped frame member, a horizontal lattice, a vertical lattice, and ears. The ear portion is formed on one side of the frame member. Further, the horizontal lattice is provided so as to be parallel to one side where the ear portion is formed in the region surrounded by the frame member, and the vertical lattice is orthogonal to the horizontal lattice in the region surrounded by the frame member. Is provided.

  A lead-acid battery using such an electrode plate is configured such that terminals and ears are electrically connected, and charging and discharging are possible via the terminals. When the lead storage battery is charged, a current flows from the ears, and a chemical reaction occurs in the active material due to the current flowing through the lattice body, so that the lead storage battery is charged. At this time, the current flowing through the lattice flows from the ear portion to each horizontal lattice. Then, when a current flows through the horizontal lattice, a chemical reaction occurs in the active material arranged around the horizontal lattice.

JP 2007-184114 A

  By the way, the current flowing through the lattice during charging is larger in the portion closer to the ear portion and becomes smaller as the portion is separated from the ear portion. This is because, due to a voltage drop due to the internal resistance of the vertical grid, a voltage difference occurs between a portion close to the ear portion and a portion far from the ear portion in the vertical grid as the distance from the ear portion increases. Therefore, in the grid of the positive electrode plate and the negative electrode plate, a chemical reaction is more likely to occur in the active material near the ear than in the active material far from the ear. On the other hand, the active material in the part far from the ear part is less likely to cause a chemical reaction than the active material in the part near the ear part. For this reason, in the grid of the positive electrode plate, the portion close to the ear is overcharged and corrosion tends to proceed. On the other hand, in the lattice of the negative electrode plate, the portion far from the ear portion is difficult to be charged, so lead sulfate is accumulated and so-called sulfation is likely to occur.

  The present invention has been made paying attention to such problems existing in the prior art, and the object thereof is to equalize the current flowing in the region surrounded by the frame member during charging and discharging. The object is to provide a cast grid.

  In order to solve the above problems, the invention according to claim 1 is characterized in that the ear part is formed in a square frame-shaped frame member, an ear part formed on one side of the frame member, and an area surrounded by the frame member. A plurality of horizontal lattices extending in parallel with one side of the frame member to be formed, and extending so as to intersect the horizontal lattice in a region surrounded by the frame member, and the frame member together with the horizontal lattice A vertical lattice forming a lattice in the enclosed region, and extending the horizontal lattice in each divided region obtained by dividing the region surrounded by the frame member at a constant interval with respect to the extending direction of the vertical lattice The gist is that the total cross-sectional area in the direction orthogonal to the direction is increased as the distance from the ear portion increases.

  According to the first aspect of the present invention, the region surrounded by the frame member is divided at a predetermined interval with respect to the extending direction of the vertical lattice, and the cutting in the direction orthogonal to the extending direction of the horizontal lattice is performed in each divided region. Since the total area is increased as the distance from the ear portion increases, the resistance value in the extending direction decreases as the horizontal lattice in the divided region that separates from the ear portion when a current flows through the cast lattice during charging / discharging. For this reason, the voltage in the extending direction of the vertical lattice decreases as the distance from the ear portion increases, but the resistance in the extending direction of the horizontal lattice decreases as the distance from the ear portion increases. As a result, it is possible to equalize the current flowing in the region surrounded by the frame member during charging and discharging.

  As described in claim 2, in the cast lattice body according to claim 1, the plurality of horizontal lattices have the same cross-sectional area in a direction orthogonal to the extending direction and adjacent horizontal regions in each divided region. By increasing the number of grids as the distance from the ears increases, the area surrounded by the frame member is divided at a fixed interval with respect to the vertical grid extension direction, and is orthogonal to the horizontal grid extension direction. The sum of the cross-sectional areas in the direction of making may be increased as the distance from the ear portion increases.

  According to a third aspect of the present invention, in the cast lattice body according to the first aspect, the plurality of horizontal lattices have the same distance between adjacent horizontal lattices and are orthogonal to the extending direction of the horizontal lattice in each divided region. As the cross-sectional area in the direction to be separated becomes larger as the region is separated from the ear part, the horizontal lattice is extended in each divided region obtained by dividing the region surrounded by the frame member at a constant interval with respect to the vertical lattice extending direction. You may enlarge so that the sum total of the cross-sectional area in the direction orthogonal to a direction is spaced apart from an ear | edge part.

  As described in claim 4, in the cast lattice body according to claim 3, the plurality of horizontal lattices have the same distance between adjacent horizontal lattices, and each divided region is provided with a plurality of horizontal lattices. The cross-sectional area in the direction orthogonal to the extending direction of some of the plurality of horizontal lattices provided in each divided region increases as the region is separated from the ear portion, thereby adjacent the horizontal lattices. And the cross-sectional area in the direction perpendicular to the extending direction of the horizontal lattice in each of the divided regions may be increased as the region is separated from the ear portion.

  According to a fifth aspect of the present invention, in the cast grid body according to any one of the first to fourth aspects, the cast grid body includes a pair of a positive electrode plate and a negative electrode plate, and the positive electrode When the frame member of the casting grid body for the plate and the frame member of the casting grid body for the negative electrode plate are overlapped, the intersection of the vertical lattice and the horizontal lattice in the casting grid body for the positive electrode plate, and the negative electrode The gist is that the intersecting portion of the vertical lattice and the horizontal lattice in the cast lattice body for plates is shifted.

  According to the invention described in claim 5, the intersecting portion of the vertical lattice and the horizontal lattice in the casting grid for the positive electrode plate is shifted from the intersecting portion of the vertical lattice and the horizontal lattice in the cast lattice for the negative electrode plate. Be placed. For this reason, the active material can be stably held between the cast grid for the positive electrode plate and the negative grid for the negative plate.

  ADVANTAGE OF THE INVENTION According to this invention, the equalization of the electric current which flows in the area | region enclosed by the frame member at the time of charging / discharging can be achieved.

The disassembled perspective view which shows the positive / negative electrode plate in the state which abbreviate | omitted the active material in embodiment. (A) is a front view of the positive / negative electrode plate in embodiment, (b) is the sectional view on the AA line of (a). (A) is a front view which shows the casting grid body of the positive electrode plate in embodiment, (b) is a front view which shows the casting grid body of the negative electrode plate in embodiment. (A)-(d) is a figure for demonstrating the derivation | leading-out method of the distance of an adjacent horizontal lattice. (A) is a front view of the cast lattice body in embodiment, (b) is a graph showing the I _t / A value in each divided region. The front view which shows the casting grid body of another example. The front view which shows the casting grid body of another example. The front view which shows the casting grid body of another example.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the positive electrode plate 1 and the negative electrode plate 2 constitute a positive and negative electrode plate 4 by sandwiching a retainer 3. And a lead acid battery is comprised by accommodating the some electrode plate 4 in the case which is not shown in figure.

  As shown in FIGS. 2A and 2B, the positive electrode plate 1 includes a cast grid body 11 and an active material 51 held by the cast grid body 11. Therefore, in the present embodiment, the cast grid 11 is a cast grid for the positive electrode plate 1. The negative electrode plate 2 includes a cast grid body 21 and an active material 52 held by the cast grid body 21. Therefore, in this embodiment, the cast grid body 21 is a cast grid body for the negative electrode plate 2. The cast grid body 11 of the positive electrode plate 1 and the cast grid body 21 of the negative electrode plate 2 are both lead cast grid bodies.

As shown in FIG. 3A, the casting grid 11 of the positive electrode plate 1 is composed of a frame member 12 having a square frame shape, a horizontal grid 13, a vertical grid 14, and ears 16.
The frame member 12 is formed of a first side 12a and a second side 12b facing each other, and a third side 12c and a fourth side 12d facing each other. The first side 12a and the second side 12b extend in the horizontal direction, and the third side 12c and the fourth side 12d extend in the vertical direction. The first side 12a is positioned on the upper side, the second side 12b is positioned on the lower side, the third side 12c is positioned on the left side, and the fourth side 12d is positioned on the right side. Each of the sides 12a to 12d has a hexagonal cross section in a direction orthogonal to the extending direction. A square plate-like ear 16 is formed on the left side of the first side 12a. Therefore, in the present embodiment, one side where the ear portion 16 is formed is the first side 12a.

  A plurality of horizontal lattices 13 are extended in parallel with the first side 12 a in the region surrounded by the frame member 12. Here, “parallel” does not indicate parallelism in a strict sense, and the horizontal lattice 13 may be extended so as to be slightly inclined with respect to the first side 12 a of the frame member 12. . That is, the horizontal lattice 13 only needs to extend substantially parallel to the first side 12a where the ears 16 are formed.

  The vertical lattice 14 extends so as to intersect with the horizontal lattice 13 (orthogonal in the present embodiment) in a region surrounded by the frame member 12. The vertical lattice 14 extends from the first side 12a to the third side 12c. The vertical lattice 14 forms a lattice in a region surrounded by the frame member 12 together with the horizontal lattice 13. As for the shape of the horizontal lattice 13 and the vertical lattice 14, the cross section in the direction orthogonal to the extending direction is hexagonal like the sides 12a to 12d of the frame member 12.

  In this embodiment, each horizontal lattice 13 has the same cross-sectional area in the direction orthogonal to the extending direction, and the area surrounded by the frame member 12 is constant with respect to the extending direction of the vertical lattice 14. The number of adjacent horizontal lattices 13 in each divided region divided at intervals increases as the region is separated from the ear portion 16. That is, by narrowing the distance between adjacent horizontal grids 13 as they are separated from the ears 16, more horizontal grids 13 are formed in regions that are farther from the ears 16. As a result, the sum of the cross-sectional areas in the direction perpendicular to the extending direction of the horizontal lattice 13 in each divided region obtained by dividing the region surrounded by the frame member 12 at a constant interval with respect to the extending direction of the vertical lattice 14 is the ear. The distance from the portion 16 increases.

As shown in FIG. 3B, the cast grid body 21 of the negative electrode plate 2 is composed of a frame member 22 having a square frame shape, a horizontal grid 23, a vertical grid 24, and ears 26.
The frame member 22 is formed of a first side 22a and a second side 22b that face each other, and a third side 22c and a fourth side 22d that face each other. The first side 22a and the second side 22b extend in the horizontal direction, and the third side 22c and the fourth side 22d extend in the vertical direction. The first side 22a is positioned on the upper side, the second side 22b is positioned on the lower side, the third side 22c is positioned on the right side, and the fourth side 22d is positioned on the left side. Each of the sides 22a to 22d has a hexagonal cross section in a direction orthogonal to the extending direction. A square plate-like ear 26 is formed on the right side of the first side 22a. Therefore, in the present embodiment, the one side on which the ear part 26 is formed is the first side 22a.

  A plurality of horizontal lattices 23 are extended in parallel with the first side 22 a in the region surrounded by the frame member 22. Note that “parallel” here does not indicate parallelism in a strict sense, and the horizontal lattice 23 may be extended so as to be slightly inclined with respect to the first side 22 a of the frame member 22. . That is, the horizontal lattice 23 only needs to extend substantially parallel to the first side 22a where the ears 26 are formed.

  The vertical lattice 24 extends so as to intersect with the horizontal lattice 23 (orthogonal in the present embodiment) in a region surrounded by the frame member 22. The vertical lattice 24 extends from the first side 22a to the third side 22c. The vertical lattice 24 forms a lattice in the region surrounded by the frame member 22 together with the horizontal lattice 23. As for the shape of the horizontal lattice 23 and the vertical lattice 24, the cross section in the direction orthogonal to the extending direction is hexagonal like the sides 22a to 22d of the frame member 22.

  In the present embodiment, each horizontal lattice 23 has the same cross-sectional area in the direction orthogonal to the extending direction, and the region surrounded by the frame member 22 is constant with respect to the extending direction of the vertical lattice 24. The number of adjacent horizontal lattices 23 in each divided region divided by the interval increases as the region is separated from the ear portion 26. That is, by narrowing the distance between adjacent horizontal grids 23 as they are separated from the ears 26, more horizontal grids 23 are formed in regions that are separated from the ears 26. As a result, the sum of the cross-sectional areas in the direction perpendicular to the extending direction of the horizontal grid 23 in each divided area obtained by dividing the area surrounded by the frame member 22 at a constant interval with respect to the extending direction of the vertical grid 24 is The distance from the portion 26 increases.

  The casting grid body 11 of the positive electrode plate 1 and the casting grid body 21 of the negative electrode plate 2 are different in the formation positions of the horizontal grids 13 and 23 and the vertical grids 14 and 24. Specifically, as shown in FIG. 2A, in each of the cast grid bodies 11 and 21, the frame member 12 of the cast grid body 11 of the positive electrode plate 1 and the frame member 22 of the cast grid body 21 of the negative electrode plate 2 overlap each other. At this time, the crossing portion 15 of the vertical lattice 14 and the horizontal lattice 13 in the cast lattice body 11 of the positive electrode plate 1 and the crossing portion 25 of the vertical lattice 24 and the horizontal lattice 23 in the cast lattice body 21 of the negative electrode plate 2 are shifted. Will be placed. In the present embodiment, the intersection 15 of the horizontal lattice 13 of the positive electrode plate 1 and the vertical lattice 14 of the positive electrode plate 1 is at the center in the region surrounded by the horizontal lattice 23 of the negative electrode plate 2 and the vertical lattice 24 of the negative electrode plate 2. It is arranged to be located. That is, the horizontal grid 13 of the cast grid 11 of the positive electrode plate 1 and the horizontal grid 23 of the cast grid 21 of the negative electrode plate 2 are arranged with a half pitch shift, and the vertical grid of the cast grid 11 of the positive electrode plate 1. The grid 14 and the vertical grid 24 of the cast grid 21 of the negative electrode plate 2 are arranged with a half-pitch shift.

  In this embodiment, regardless of the distance from the ears 16 and 26 in the extending direction of the vertical grids 14 and 24, chemical reactions are equally generated in the active materials 51 and 52 held by the cast grid bodies 11 and 21. Thus, the distance between adjacent horizontal grids 13 and 23 is set. Specifically, the distance between the adjacent horizontal grids 13 and 23 in the extending direction of the vertical grid 14 is determined according to the following method.

  Hereinafter, a method for deriving the distance between the adjacent horizontal lattices 13 will be described with reference to FIGS. In the following description, a method for deriving the distance between adjacent horizontal grids 13 in the cast grid body 11 of the positive electrode plate 1 will be described. A similar method can be used.

As preconditions, the horizontal lattice 13 has the same cross-sectional area in the direction perpendicular to the extending direction, and the vertical lattice 14 ignores the resistance value in the extending direction. The terminal potential on the side 12d side is the same potential. Also, as the horizontal grid 13 ears 16 are most apart from forming the first side 12a which is formed as a first horizontal grid y _1, closer to the ear portion 16, the second horizontal grid y ₂ The third horizontal lattice y ₃ ... Is defined as the _nth horizontal lattice yn. Also, define the distance from the central axis of the second side 12b of the frame member 12 to the first central axis of the horizontal grid y ₁ and the minimum distance l _1.

Then, when a current flows in the n-th horizontal grid y _{n (n} is an arbitrary number), region where chemical reaction occurs in the active material 51 due to the current i _n flowing through the n-th horizontal grid y _n is , defined by the n-th horizontal grid adjacent the center axis of the horizontal grid _{y n} of _{y n-1, y n} spreads toward _{the + 1} distance _{l n.} That is, the horizontal grid _{y n-1, y n} spreads toward the _{+ 1} distance _{l n (= 2 · l n} ) is the current n-th horizontal grid _{y n} flow adjacent around the n-th horizontal grid _{y n} It becomes the reaction range where a chemical reaction occurs in the active material 51 at the time. Then, according to the reaction range (2 · l _n ), the separation distance between the adjacent horizontal lattices y _{n + 1} and y _n−1 is set so that a current flows.

The cast lattice body 11 can be represented by an equivalent circuit shown in FIG. 4D with respect to the front view of FIG.
Specifically, the resistance r of the horizontal lattice y _n (n is an arbitrary number) can be obtained from the following equation (1). Further, the end portion of the n-th horizontal grid y _n in the third side 12c, the resistance R _n between the n + 1 th end of the horizontal grid y _{n + 1} can be obtained by the following formula (2).

However, [rho is the resistivity of the lead (material of the cast grid 11), W is the lateral lattice y _n extending direction of the length of, S2 are perpendicular to the extending direction of the horizontal grid y _n shown in FIG. 4 (c) It is a cross-sectional area in the direction to do. (1) In the formula, W values of the horizontal grid _{y n,} S2 value, since ρ values are equal, r value is also equal, so that the resistance r of the lateral grid _y 1 _{~y n + 1} are all the same. _Further, l n _{+ l n + 1} is a horizontal grid _{y n} n-th in the third side 12c, n + 1-th horizontal grid _{y n +} length between ₁ (n-th horizontal from the center axis (n + 1) th of the lateral lattice _{y n} Distance to the central axis of the lattice yn _{+ 1} ). S1 is a cross-sectional area in a direction orthogonal to the extending direction of the third side 12c shown in FIG.

Then, the distance between the adjacent horizontal lattices y _n−1 and y _{n + 1} is derived from the equivalent circuit of FIG.
The current flowing through the _nth lateral lattice y _n (resistor r) is i _n , the current flowing through the (n + 1) th lateral lattice y _{n + 1} (resistor r) is i _{n + 1} , and the resistor R _n (the nth lateral in the third side 12c). the current flowing through the portion) sandwiched between the lattice _{y n} and n + 1 th horizontal grid _{y n + 1} and _{i Rn.} Here, i _Rn can be expressed by the following formula (3).

Further, the following equation (4) is established from the condition that the terminal potential on the fourth side 12d side in each of the horizontal lattices y _{1 to} yn _{+ 1} is the same potential and the above equation (3).

Here, in proportion to n-th reaction range horizontal grid _{y n (2 · l n)} , the horizontal grid _{y n} + 1 adjacent to the current _{i n} increases through the n-th horizontal grid _{y n, y n In} order to set the distance of ₋₁ , the current flowing in the _nth horizontal lattice yn can be expressed by the following equation (5).

Here, I is the total current flowing through the cast grid 11, and L is the length of the third side 12c (fourth side 12d) of the frame member 12 in the extending direction. That is, to flow and per unit length of the current (= I / L), n-th horizontal grid _{y n} current _{i n} obtained by multiplying the reaction range (2 · _{l n)} of the respective horizontal grid _{y 1 ~y n +} 1 Is set to the distance between the horizontal lattices y _{n + 1} and y _n−1 adjacent to. As a result, the current flowing in proportion to the reaction range (2 · l _n ) of the _nth horizontal lattice yn increases.

From the above conditions, when a current flows through the n-th horizontal grid y _n, to derive the distance l _n extending toward the lateral lattice _{y n-1, y n +} 1 adjacent around a horizontal grid y _n.
By substituting the equations (2) and (5) into the equation (4), the following equation (6) can be derived.

As can be seen from equation (6), the distance l _{n + 1} can be derived from the distance l _n . Therefore, by determining the minimum distance _{l 1,} it is possible to determine the lateral lattice _{y 1 ~y n +} 1 of the distance _{l n} for all adjacent. The minimum separation distance l ₁ can be arbitrarily set as long as the _nth lateral lattice yn and the (n + 1) th lateral lattice yn _{+ 1} do not overlap.

when a current flows through the n-th horizontal grid _{y n,} by deriving the distance _{l n} extending toward the lateral lattice _{y n-1, y n +} 1 adjacent around a horizontal grid _{y n,} n-1 th the distance d of the horizontal grid y _n-1 and n-th horizontal grid y _n of can be defined by the following equation (7).

When the distance between the adjacent horizontal lattices y _n−1 and y _{n + 1} is set in this way, the following equation (8) is established from the preconditions.

Ie, n-th horizontal grid _y n (n is arbitrary) All current density is the same reaction range (2 · _{l n).}

Next, the operation of the cast grid bodies 11 and 21 in the present embodiment will be described with reference to FIGS.
At the time of charging the lead storage battery using the electrode plate 4 in the present embodiment, a chemical reaction occurs in the active materials 51 and 52 due to a current flowing from the negative electrode plate 2 to the positive electrode plate 1, and the lead storage battery is charged. At this time, current flows from the ear portion 16 in the cast grid 11 of the positive electrode plate 1. The current flowing from the ear 16 flows to the horizontal grid 13 via the vertical grid 14. In this way, the current flowing from the ear portion 16 flows through the entire cast grid 11. However, the voltage in the vertical grid 14 decreases as the distance from the ear portion 16 increases due to the internal resistance of the vertical grid 14. Then, based on the voltage drop of the vertical grid 14, the current flowing through the horizontal grid 13 becomes smaller as the horizontal grid 13 is farther from the ear portion 16 (as the bottom horizontal grid 13). For this reason, the current flowing through the cast lattice body 21 also decreases as the lateral lattice 23 is separated from the ear portion 26.

  On the other hand, current flows from the positive electrode plate 1 to the negative electrode plate 2 when discharging the lead storage battery using the electrode plate 4 in the present embodiment. At this time, in the cast lattice body 11 of the positive electrode plate 1, a current flows toward the ear portion 16. The current flowing toward the ear portion 16 flows to the vertical lattice 14 via the horizontal lattice 13. However, the voltage of the vertical grid 14 becomes lower as it approaches the ear 16 due to the internal resistance of the vertical grid 14. That is, in the cast grid body 11 of the positive electrode plate 1 and the cast grid body 21 of the negative electrode plate 2, there is a difference in current flowing between a portion near the ear portions 16 and 26 and a portion far from the ear portions 16 and 26.

In this embodiment, the horizontal grids 13 and 23 of the cast grid bodies 11 and 21 are configured such that the distance between the adjacent horizontal grids 13 and 23 decreases as the distance from the ear portions 16 and 26 increases. For this reason, as shown in FIG. 5A, each divided region obtained by dividing the region surrounded by the frame member 12 in the cast lattice body 11 of the present embodiment into four at regular intervals in the extending direction of the vertical lattice 14. The total cross-sectional area in the direction orthogonal to the extending direction of the horizontal lattice 13 in A1 to A4 increases as the distance from the ear portion 16 increases. That is, the combined resistance of the horizontal lattice 13 in each of the divided regions A1 to A4 is smaller as the region is farther from the ear. FIG. 5B shows the distribution of current density (I _t / A) in each of the divided regions A1 to A4 for the present embodiment and the comparison target. As a comparison object, a cast grid having the same distance between adjacent horizontal grids is used.

In FIG. 5B, the vertical axis represents the current density I _t / A, and the horizontal axis corresponds to each of the divided regions A1 to A4. Here, I _t is the sum of the currents flowing in the horizontal grid 13 in each of the divided areas Al to A4, A is the cross-sectional area in a direction orthogonal to the extending direction of the transverse grating 13 in each divided region Al to A4 It is. Therefore, I _t / A indicates a current flowing per unit area (= current density). As is apparent from FIG. 5B, the cast grid body 11 in the present embodiment has a smaller current density deviation between the divided regions A1 to A4 than the cast grid body to be compared. I understand that.

  Therefore, the difference in the likelihood of a chemical reaction between the active materials 51 and 52 near the ears 16 and 26 and the active materials 51 and 52 far from the ears 16 and 26 is reduced. That is, the positive electrode plate 1 and a part of the negative electrode plate 2 are prevented from being locally charged. Similarly, part of the positive electrode plate 1 and the negative electrode plate 2 is prevented from being locally discharged even when the lead storage battery is discharged.

  In addition, when the positive electrode plate 1 and the negative electrode plate 2 of the present embodiment are placed sideways, that is, arranged so that one surface in the thickness direction of the cast grid bodies 11 and 21 is horizontal (opposed to the ground), the active materials 51 and 52 Tends to drop downward from the region surrounded by the horizontal grids 13 and 23 and the vertical grids 14 and 24 due to gravity. However, in the present embodiment, the intersecting portion 15 of the cast grid body 11 of the positive electrode plate 1 and the intersecting portion 25 of the cast grid body 21 of the negative electrode plate 2 are shifted from each other. Specifically, the intersecting portion 15 of the cast grid body 11 of the positive electrode plate 1 and the intersecting portion 25 of the cast grid body 21 of the negative electrode plate 2 are arranged so as to be shifted by a half pitch. For this reason, the intersecting portions 15 and 25 are arranged below the region surrounded by the horizontal lattices 13 and 23 and the vertical lattices 14 and 24, and the active materials 51 and 52 are supported by the lower intersecting portions 15 and 25. Further, since the cast grid body 11 of the positive electrode plate 1 and the cast grid body 21 of the negative electrode plate 2 are formed so as to be shifted, unevenness is hardly caused in the way the active materials 51 and 52 are used.

According to the above embodiment, the following effects can be obtained.
(1) Regardless of the distance from the ears 16 and 26, the horizontal grids 13 and 23 are separated so that the chemical reaction occurs evenly in the active materials 51 and 52 based on the current flowing through the horizontal grids 13 and 23. The distance is set. Therefore, a chemical reaction is likely to occur also in the active materials 51 and 52 in the portions far from the ears 16 and 26, and it is possible to prevent a part of the positive electrode plate 1 and the negative electrode plate 2 from being locally charged and discharged. That is, the current flowing in the region surrounded by the frame member 12 during charge / discharge is equalized.

  (2) The cast grid bodies 11 and 21 of the present embodiment exhibit the effect particularly when the cast grid bodies 11 and 21 are thinned. When the cast grid bodies 11 and 21 are formed to be thin, the current flowing through the horizontal grids 13 and 23 in the portions far from the ear portions 16 and 26 and the current flowing through the horizontal grids 13 and 23 in the portions close to the ear portions 16 and 26. The difference between Since the cast grid bodies 11 and 21 in the present embodiment have less current density unevenness in each of the divided regions A1 to A4, the active materials 51 and 52 even if there is a difference in current between the horizontal grids 13 and 23. Chemical reactions are likely to occur evenly.

  (3) The intersection 15 of the casting grid 11 of the positive electrode plate 1 and the intersection 25 of the casting grid 21 of the negative electrode 2 are shifted from each other. For this reason, the usage of the active materials 51 and 52 is less likely to be biased. Therefore, a part of the active materials 51 and 52 is prevented from being used locally, and deterioration of the active materials 51 and 52 is suppressed.

  (4) Further, when the electrode plate 4 of this embodiment is placed horizontally, the active materials 51 and 52 are directed toward the ground from the region surrounded by the horizontal grids 13 and 23 and the vertical grids 14 and 24 according to gravity. It becomes easy to drop off. However, in the cast grid bodies 11 and 21 of the present embodiment, the intersecting portion 15 of the cast grid body 11 of the positive electrode plate 1 and the intersecting portion 25 of the cast grid body 21 of the negative electrode plate 2 are shifted from each other. 15 and 25 are arranged below the area surrounded by the horizontal grids 13 and 23 and the vertical grids 14 and 24 (in the ground direction). For this reason, when the active materials 51 and 52 try to drop off, the intersections 15 and 25 support the active materials 51 and 52. Therefore, the active materials 51 and 52 are difficult to drop off.

(5) Further, when the active materials 51 and 52 of the positive electrode plate 1 and the negative electrode plate 2 expand, respectively, the intersections 15 and 25 are displaced, so that stress is not easily applied to the cast lattice bodies 11 and 21.
(6) Further, since the retainer 3 can be supported uniformly from both sides, the retainer 3 is difficult to sag.

In addition, you may change embodiment as follows.
As shown in FIG. 6, the distance between adjacent horizontal grids 13 may be changed at regular intervals. In the cast lattice body 11 shown in FIG. 6, the separation distance of the horizontal lattices arranged in each of the ranges H1 to H4 is the same. Further, the separation distance of the horizontal lattice 13 arranged in the range H1 is the longest, and the separation distance of the horizontal lattice arranged in the range H4 is the shortest. Also in this case, the difference in current density in each divided region is reduced. In FIG. 6, only the cast grid body 11 of the positive electrode plate 1 is shown, but the cast grid body 21 of the negative electrode plate 2 may be configured in this way.

  As shown in FIG. 7, the distances between adjacent horizontal lattices 13 a to 13 d are made the same, and a part of the horizontal lattices 13 b to 13 d out of the plurality of horizontal lattices 13 a to 13 d provided in each divided region is extended. The cross-sectional area in the direction orthogonal to the direction may be increased as the region is separated from the ear portion 16. There is one thicker horizontal lattice 13b for the thinnest horizontal lattice 13a, one thicker horizontal lattice 13c below it, and one thicker horizontal lattice 13d below that. is there. That is, in the cast grid body 11 shown in FIG. 7, the cross-sectional area in the direction orthogonal to the extending direction of the horizontal grid 13a is the smallest, and the cross-sectional area in the direction orthogonal to the extending direction of the horizontal grid 13b is It is formed larger than 13a. Further, the cross-sectional area in the direction orthogonal to the extending direction of the horizontal lattice 13c is formed larger than that of the horizontal lattice 13b, and the cross-sectional area in the direction orthogonal to the extending direction of the horizontal lattice 13d is It is formed larger than. By constructing the cast lattice 11 in this way, the region surrounded by the frame member 12 is orthogonal to the extending direction of the horizontal lattice 13 in each divided region obtained by dividing the region surrounded by the frame member 12 at a constant interval. The sum of the cross-sectional areas in the direction to be increased increases as the distance from the ear portion 16 increases. In FIG. 7, only the cast grid body 11 of the positive electrode plate 1 is shown, but the cast grid body 21 of the negative electrode plate 2 may be configured in this way.

  As shown in FIG. 8, the distance between adjacent horizontal lattices 13 is the same, and the cross-sectional area in the direction orthogonal to the extending direction of the horizontal lattice 13 in each divided region is larger as the region is separated from the ear portion 16. May be. By constructing the cast lattice 11 in this way, the region surrounded by the frame member 12 is orthogonal to the extending direction of the horizontal lattice 13 in each divided region obtained by dividing the region surrounded by the frame member 12 at a constant interval. The sum of the cross-sectional areas in the direction to be increased increases as the distance from the ear portion 16 increases. In FIG. 8, only the cast grid body 11 of the positive electrode plate 1 is shown, but the cast grid body 21 of the negative electrode plate 2 may be configured in this way.

  In the embodiment, each side 12a to 12d of the frame member 12, the vertical lattices 14 and 24, and the horizontal lattice 13 may have a shape other than a hexagonal shape. For example, a polygonal shape such as a quadrangular shape or a pentagonal shape, or a circular shape may be used.

  The vertical lattice 14 does not need to extend so as to be orthogonal to the horizontal lattice 13. In other words, the vertical lattice 14 may intersect with the horizontal lattice 13 and may intersect obliquely.

  A1, A2, A3, A4 ... divided areas, 1 ... positive electrode plate, 2 ... negative electrode plate, 11, 21 ... cast lattice body, 12, 22 ... frame member, 12a, 22a ... first side, 13, 13a, 13b , 13c, 13d, 23 ... horizontal lattice, 14, 24 ... vertical lattice, 15, 25 ... crossing portion, 16, 26 ... ear portion, 51, 52 ... active material.

Claims (5)

A square frame-shaped frame member;
Ears formed on one side of the frame member;
A plurality of horizontal lattices extending in parallel with one side of the frame member in which the ear portion is formed in a region surrounded by the frame member;
A vertical lattice that extends so as to intersect the horizontal lattice in a region surrounded by the frame member, and that forms a lattice in the region surrounded by the frame member together with the horizontal lattice,
The sum of the cross-sectional areas in the direction perpendicular to the extending direction of the horizontal lattice in each divided region obtained by dividing the region surrounded by the frame member at a constant interval with respect to the extending direction of the vertical lattice from the ear portion. A cast lattice body which is enlarged as it is separated.   The plurality of horizontal lattices have the same cross-sectional area in the direction orthogonal to the extending direction, and the number of the adjacent horizontal lattices in each divided region increases as the region is separated from the ear portion. The sum of the cross-sectional areas in the direction perpendicular to the extending direction of the horizontal lattice in each divided region obtained by dividing the region surrounded by the frame member at a constant interval with respect to the extending direction of the vertical lattice from the ear portion. The cast lattice body according to claim 1, wherein the cast lattice body is made larger as the distance increases.   The plurality of lateral lattices have the same distance between adjacent lateral lattices, and the cross-sectional area in the direction perpendicular to the extending direction of the lateral lattice in each divided region is larger as the region is separated from the ear portion. Thus, the sum of the cross-sectional areas in the direction perpendicular to the extending direction of the horizontal lattice in each divided region obtained by dividing the region surrounded by the frame member at a constant interval with respect to the extending direction of the vertical lattice. The cast lattice body according to claim 1, wherein the cast lattice body is made larger as the distance from the ear portion increases.   Each divided region is provided with a plurality of horizontal lattices, and a cross-sectional area in a direction orthogonal to the extending direction of some of the plurality of horizontal lattices provided in each divided region is the ear portion. The distance between adjacent horizontal lattices is the same, and the cross-sectional area in the direction perpendicular to the extending direction of the horizontal lattice in each of the divided regions is separated from the ear portion. The cast lattice body according to claim 3, wherein the cast lattice body is made larger in size.   The cast lattice body includes a pair of positive electrode plate and negative electrode plate, and the positive electrode plate when the frame member of the cast lattice body for the positive electrode plate and the frame member of the cast lattice body for the negative electrode plate are stacked. The crossing portion of the vertical lattice and the horizontal lattice in the casting lattice body for use, and the crossing portion of the vertical lattice and the horizontal lattice in the casting lattice body for the negative electrode plate are arranged so as to be shifted. The cast lattice body according to any one of claims 1 to 4.