Shovel

1. A shovel comprising:

a lower traveling body;

an upper swivel body mounted on the lower traveling body via a swiveling bearing;

a boom attached to the upper swivel body;

a power storage device mounted on the upper swivel body; and

an electrically driven part driven by discharged electric power from the power storage device,

wherein the power storage device includes:

a lower housing having a bottom panel, side panels, and an opening portion that opens upward;

a lid closing the opening portion;

at least two power storage modules arranged at a distance from each other in a first direction on the bottom panel and configured to charge and discharge electrical energy;

a first rib formed on the bottom panel of the lower housing, arranged between the two power storage modules, and configured to extend in a second direction intersecting in the first direction; and

a second rib formed on the bottom panel of the lower housing, configured to extend in the first direction, and formed continuously with the first rib,

wherein the lower housing and the lid apply a compressive force in a height direction to the power storage modules.

2. The shovel according to claim 1 ,

wherein the second rib overlaps each of the power storage modules about the first direction.

3. The shovel according to claim 2 , wherein the power storage device further comprises a third rib, which respectively extend from both ends of the second rib in the second direction away from the power storage module and reach the one side panel.

4. The shovel according to claim 1 , further comprising:

a lid configured to close an upper opening portion of the lower housing,

wherein the first rib and the second rib are lower than the side plates, and gaps are formed between the first rib and the lid and between the second rib and the lid in a state where the opening portion of the lower housing is closed with the lid.

5. The shovel according to claim 1 ,

wherein the second rib extends in the first direction from the first rib, and reaches the side panels intersecting the first direction.

6. The shovel according to claim 1 , further comprising:

a plurality of side panel ribs formed on inside surfaces of the side panels,

wherein the side panel ribs are in contact with the bottom panel, extend upward from the bottom panel, and are discretely arranged in a circumferential direction.

7. The shovel according to claim 6 ,

wherein an inwardly-directed surface of each of the side panel ribs includes a region which inclines so that the side panel rib becomes thin upward from the bottom panel.

8. The shovel according to claim 1 ,

wherein the bottom panel of the lower housing includes a pair of first edges parallel to each other, and

wherein when the thickness of the portions of the side panels formed continuously with the first edges and connected to the bottom panel is represented as Ws, and the

spacing between the first edges is represented as Wb, the value of Ws/Wb is equal to or greater than 0.03.

9. The shovel according to claim 8 ,

wherein inwardly-directed surfaces of the side panels formed continuously with the first edges incline so that the side panels become thin upward from the bottom panel.

10. The shovel according to claim 1 , wherein the side panels are arranged throughout an outer peripheral line of the bottom panel.

11. The shovel according to claim 10 , wherein each of the power storage module is disposed between one side panel and the first rib in the first direction and between one side panel and the second rib in the second direction.

12. The shovel according to claim 1 , wherein the bottom panel, the side panels, the first rib and the second rib are integrally molded by a casting process.

13. A shovel comprising:

a power storage device; and

an electrically driven part driven by discharged electric power from the power storage device,

wherein the power storage device includes:

a lower housing having a bottom panel and side panels;

at least two power storage modules arranged at a distance from each other in a first direction on the bottom panel and configured to charge and discharge electrical energy;

a first rib formed on the bottom panel of the lower housing, arranged between the two power storage modules, and configured to extend in a second direction intersecting in the first direction; and

a second rib formed on the bottom panel of the lower housing, configured to extend in the first direction, and formed continuously with the first rib,

wherein each of the power storage modules includes:

a plurality of plate-shaped power storage cells stacked in a thickness direction; and

a pressurizing mechanism configured to apply a compressive force in a stacking direction to a stacked body of the power storage cells, and

wherein the second rib is arranged between the power storage cells within the power storage module, and the compressive force generated by the pressurizing mechanism is applied to the second rib.

14. The shovel according to claim 13 ,

wherein the pressurizing mechanism has pressurizing plates arranged at both ends of the stacked body of the power storage cells stacked in the thickness direction,

wherein the power storage cells are connected in series, and

wherein the power storage module further includes:

an insulator fixed to an outside surface of each of the pressurizing plates; and

terminals attached to the insulator and electrically connected to both ends of a series connection circuit of the power storage cells.