Electricity storage device

1. An electricity storage device comprising:

a plurality of electricity storage cells;

a casing having at least a pair of side plates and storing the electricity storage cells;

a control device which controls the electricity storage cells;

one or more voltage detection conductors integral to each of the side plates and having first end parts electrically connected to the electricity storage cells;

voltage detection lead wires electrically connecting the voltage detection conductor with the control device; and

one or more connection devices each including a current interruption unit which is configured to be capable of interrupting electric current from the electricity storage cells and a side plate-side connector to which a lead wire-side connector of the voltage detection lead wires is connected, the connection devices electrically connecting the one or more voltage detection conductors with the voltage detection lead wires via the current interruption unit, wherein:

the connection devices are formed integrally with each of the side plates so that the current interruption unit and the side plate-side connectors adjoin each other in a direction in which the pair of side plates face each other and a height of the side plate-side connector is less than a height of the current interruption unit in a height direction of the side plates orthogonal to the direction in which the side plates face each other, and

second end parts of the one or more voltage detection conductors and first connector end parts of side plate connector terminals of the side plate-side connector are arranged to face each other in the current interruption unit, and

the current interruption unit electrically connects the second end parts of the voltage detection conductors with the first connector end parts of the side plate connector terminals by use of fuse wires, and

each of the side plate-side connectors includes a connector housing which is formed at a position lower than the height of the current interruption unit in the height direction of the side plates and the side plate connector terminals which extend from the current interruption unit to the connector housing, and

each of the side plate connector terminals has the first connector end parts arranged in the current interruption unit, second connector end parts arranged in the connector housing and connected to the lead wire-side connector, and a bending part bending the side plate connector terminal between the first connector end parts and the second connector end parts.

2. The electricity storage device according to claim 1 , wherein:

the fuse wires have a curved part formed between a first connection end connected to the second end parts of the one or more voltage detection conductors and a second connection end connected to the first connector end parts of the side plate connector terminals, and

the current interruption unit has a concave part which is formed between the position where the second end parts of the voltage detection conductor and the first connection end of the fuse wires are arranged and the position where the first connector end parts of the side plate connector terminals and the second connection end of the fuse wires are arranged, and

the curved part of the fuse wires is stored in the concave part in a state in which the first connection end and the second connection end of the fuse wires have been connected to the second end parts of the one or more voltage detection conductors and the first connector end parts of the side plate connector terminals, respectively.

3. The electricity storage device according to claim 1 , wherein:

the voltage detection conductor is made up of a plurality of conductor elements corresponding to the electricity storage cells, and

a fuse connection part of each conductor element forms the second end parts of the voltage detection conductor, and

the side plate connector terminals are made up of a plurality of connector elements corresponding to the conductor elements, and

a fuse connection terminal of each connector element forms the first connector end part of the side plate connector terminals, and

each of the fuse wires connecting the fuse connection part with a fuse terminal part extends in the height direction of the side plates, and

a plurality of sets each including the fuse connection part, the fuse connection terminal and the fuse wires are arranged in parallel inside a peripheral wall which demarcates the periphery of the current interruption unit.

4. The electricity storage device according to claim 3 , wherein positioning parts for positioning the fuse wires of the sets are arranged along a first inner surface of the peripheral wall on a side of the fuse connection part and along a second inner surface of the peripheral wall on a side of the fuse connection terminal.

5. The electricity storage device according to claim 3 , wherein a partition wall is provided between adjacent ones of the sets.

6. The electricity storage device according to claim 1 , wherein the one or more connection devices further include:

a first formation part in which the second end parts of the voltage detection conductor and the first connector end parts of the side plate connector terminals are integrated together by a resin part; and

a second formation part in which a peripheral wall demarcating the periphery of the current interruption unit is formed while exposing the second end parts of the voltage detection conductor and the first end parts of the side plate connector terminals.

7. The electricity storage device according to claim 1 , wherein a top of the connector housing in regard to the height direction is provided with a lock part for the lead wire-side connector.

8. The electricity storage device according to claim 1 , wherein the current interruption unit is injected with silicone gel.

9. The electricity storage device according to claim 1 , wherein:

the one or more connection devices have a cap which covers an exposed part of the current interruption unit, and

the cap and the current interruption unit are connected together by spigot fitting structure.

10. The electricity storage device according to claim 2 , wherein:

the first connector end part of the side plate connector terminals extend in the height direction of the side plates, and

the second connector end parts of the side plate connector terminals extend in the direction in which the side plates face each other, and

the bending part of the side plate connector terminals is formed so that the connector terminal extends from the current interruption unit to the connector housing while avoiding the concave part of the current interruption unit.

11. The electricity storage device according to claim 2 , wherein:

the curved part is formed in a central part of the fuse wires, and

the concave part has a rectangular opening whose long sides are parallel to an extending direction of the fuse wires, and

a length of shorter sides of the rectangular opening is set so that the curved part makes contact with an inner wall of the concave part when the fuse wires rotate around its axis.