Grid plate for lead acid storage battery, plate, and lead acid storage battery provided with same plate

1. A grid plate for a lead acid storage battery comprising a frame section having a pair of lateral frame strands that extend in a lateral direction and oppose one another in a longitudinal direction, and a pair of longitudinal frame strands that extend in the longitudinal direction and oppose one another in the lateral direction; a plurality of lateral grid strands and a plurality of longitudinal grid strands that are provided so as to extend parallel to the lateral frame strands and the longitudinal frame strands, respectively, so that a grid is formed inside the frame section; and a plate lug section integrally formed in one lateral frame strand of the frame section, wherein

at least one of: the longitudinal grid strands or the lateral grid strands, have a plurality of thin strands having a cross-sectional area that can withstand corrosion for a predetermined service life period of the lead acid storage battery, and a plurality of thick strands that have a greater cross-sectional area than that of the thin strands, the thick strands and thin strands being arranged so that the strands adjacent to the thick strands are thin strands;

the plurality of thick strands have a thickness that is less than the thickness of the frame section, end portions of the thick strands with respect to the thickness direction are positioned further inward in the thickness direction than end face portions of the frame section, respectively, in the thickness direction of the frame section; and the thick strands are arranged in a state in which the respective end portions of one end side in the thickness direction are positioned in the same plane;

the width and thickness of the thin strands are set to be less than the width and thickness of the thick strands; and

the plurality of thin strands are provided in a state in which the respective end portions on one end side in the thickness direction, are positioned in positions closer to the plane in which the end portions of one end side of the plurality of thick strands in the thickness direction are arranged, as opposed to an opposing end side of the plurality of thick strands, but so as not to cross over the plane in which the end portions of one end side of the plurality of thick strands in the thickness direction are arranged.

2. The grid plate for a lead acid storage battery of claim 1 , wherein

the longitudinal grid strands have thick longitudinal strands that are the thick strands and thin longitudinal strands that are the thin strands; and

the lateral grid strands have thick lateral strands that are the thick strands and thin lateral strands that are the thin strands.

3. The grid plate for a lead acid storage battery of claim 2 , wherein the plurality of thin longitudinal strands and the plurality of thin lateral strands are provided in a state in which the respective end portions of one end side in the thickness direction, are positioned in the same plane as the plane in which the end portions of one end side of the thick longitudinal strands and the thick lateral strands in the thickness direction are arranged.

4. The grid plate for a lead acid storage battery of claim 2 , wherein a ratio of the number of thin lateral strands to the number of thick lateral strands provided per fixed unit area in a region adjacent to one lateral frame strand provided with the plate lug section, is greater than a ratio of the number of thin lateral strands to the number of thick lateral strands provided per fixed unit area in a region near another lateral frame strand in a position set apart from the plate lug section.

5. The grid plate for a lead acid storage battery of claim 2 , wherein

the thick longitudinal strands and the thin longitudinal strands constituting the longitudinal grid strands are disposed so that the thick longitudinal strands and the thin longitudinal strands are aligned in alternating fashion in a lengthwise direction of the lateral frame strands;

a first region and a second region are established, respectively, on one lateral frame strand side on which the plate lug section is disposed and on another lateral frame strand side in a position set apart from the plate lug section; and

the number of thin lateral strands in the first and second regions is set so that the number of thin lateral strands arranged between the mutually adjacent thick lateral strands in the first region is greater than the number of thin lateral strands arranged between the mutually adjacent thick lateral strands in the second region, where the one of the lateral frame strands and the other of the lateral frame strands are regarded as thick lateral strands.

6. The grid plate for a lead acid storage battery of claim 5 , wherein the number of thin lateral strands arranged between mutually adjacent thick lateral strands in the first region is 4, and the number of thin lateral strands arranged between mutually adjacent thick lateral strands in the second region is 3.

7. The grid plate for a lead acid storage battery of claim 2 , wherein the value obtained by dividing the width of the thick longitudinal strands by the width of the thin longitudinal strands, the value obtained by dividing the thickness of the thick longitudinal strands by the thickness of the thin longitudinal strands, the value obtained by dividing the width of the thick lateral strands by the width of the thin lateral strands, and the value obtained by dividing the thickness of the thick lateral strands by the thickness of the thin lateral strands, are in a range of 1.1 to 1.5.

8. The grid plate for a lead acid storage battery of claim 1 , wherein the lateral grid strands have thick lateral strands that are the thick strands, and thin lateral strands that are the thin strands, but the longitudinal grid strands have only thick longitudinal strands that are the thick strands.

9. The grid plate for a lead acid storage battery of claim 8 , wherein the plurality of thin lateral strands are provided in a state in which the end portions of one end side thereof in the thickness direction, are positioned in the same plane as the plane in which the end portions of the one end side in the thickness direction of the thick longitudinal strands and the thick lateral strands are arranged.

10. The grid plate for a lead acid storage battery of claim 8 , wherein a ratio of the number of thin lateral strands to the number of thick lateral strands provided per fixed unit area in a region adjacent to one lateral frame strand provided with the plate lug section, is greater than a ratio of the number of thin lateral strands to the number of thick lateral strands provided per fixed unit area in a region near another lateral frame strand in a position set apart from the plate lug section.

11. The grid plate for a lead acid storage battery of claim 8 , in which:

a first region and a second region are set near one lateral frame strand on which the plate lug section is disposed and near another lateral frame strand set apart from the plate lug section, respectively; and

a ratio of the number of thin lateral strands to the number of thick lateral strands in said first region is set as a first ratio, and a ratio of the number of thin lateral strands to the number of thick lateral strands is set as a second ratio which is less than the first ratio.

12. A plate for a lead acid storage battery, wherein an active material is packed into the grid plate of claim 1 .

13. A lead acid storage battery, wherein at least a positive plate has a configuration in which a positive active material is packed into the grid plate of claim 1 .