Secondary cell manufacturing method

1. A secondary cell manufacturing method comprising:

disposing a cap including a first magnetic body so as to cover a liquid injection hole provided in a lid member;

disposing the lid member so as to cover an opening of an outer case; and

bringing close to each other the first magnetic body and a second magnetic body that applies a magnetic force to the first magnetic body, such that a position of the cap that is disposed to cover the liquid injection hole is held by the magnetic force between the first magnetic body and the second magnetic body.

2. The secondary cell manufacturing method according to claim 1 , wherein

when the position of the cap is held by the magnetic force, the second magnetic body is disposed so as to face a side surface of the outer case, so that the first magnetic body and the second magnetic body are magnetically attracted to each other through the side surface of the outer case.

3. The secondary cell manufacturing method according to claim 1 , further comprising:

welding the lid member to the outer case, wherein

the lid member is welded to the outer case in a state where the position of the cap is held by the magnetic force.

4. The secondary cell manufacturing method according to claim 3 , further comprising:

before welding the lid member to the outer case, transferring the outer case, the lid member, and the cap, in a state where the cap is disposed over the liquid injection hole and the lid member is disposed over the opening of the outer case, to a place where welding of the lid member is performed, wherein

during transferring the outer case, the lid member, and the cap, the position of the cap is held by a magnetic repulsive force between the first magnetic body and the second magnetic body.

5. The secondary cell manufacturing method according to claim 3 , wherein:

the cap has a flange part that is disposed so as to cover the liquid injection hole and an insert part that is inserted into the liquid injection hole, and

in a state where the position of the cap is held by the magnetic force, the flange part of the cap is disposed so as to face a portion of the lid member around the liquid injection hole, with a communication path that allows communication between the inside and the outside of the outer case formed between the portion around the liquid injection hole and the flange part.

6. The secondary cell manufacturing method according to claim 5 , wherein:

the communication path is a recessed groove provided in the flange part.

7. The secondary cell manufacturing method according to claim 1 , wherein

the cap includes the first magnetic body and a resin member with the first magnetic body embedded inside.

8. The secondary cell manufacturing method according to claim 7 , wherein:

the resin member is made of perfluoro-alkoxyfluoro plastics.

9. The secondary cell manufacturing method according to claim 1 , wherein

when the cap is disposed so as to cover the liquid injection hole provided in the lid member, the cap is transferred by a transfer mechanism including a third magnetic body, and the first magnetic body and the third magnetic body are magnetically attracted to each other while the transfer mechanism is transferring the cap.

10. The secondary cell manufacturing method according to claim 9 , wherein

the transfer mechanism includes a guide that has a contact surface with which a top surface of the cap is in contact in a state where the first magnetic body and the third magnetic are magnetically attracted to each other, and

on an opposite side from the contact surface, the third magnetic body is movable relative to the guide in a direction of an axis of the cap.

11. The secondary cell manufacturing method according to claim 10 , wherein:

the contact surface has a protrusion,

the top surface of the cap has a recess, and

the protrusion and the recess are engaged with each other in the state where the first magnetic body and the third magnetic body are magnetically attracted to each other.

12. The secondary cell manufacturing method according to claim 1 , wherein:

the cap has a flange part that is disposed so as to cover the liquid injection hole and an insert part that is inserted into the liquid injection hole, and

a leading end portion of the insert part has a tapered truncated conical shape.

13. The secondary cell manufacturing method according to claim 1 , wherein:

a guide member is provided that is disposed so as to face a side surface of the outer case to hold the position of the cap by the magnetic force.