Connection method for terminal fitting and connection structure of terminal fitting

1. A connection method for a terminal fitting and a plurality of electric wire assemblies, in which the terminal fitting includes a terminal body and a plurality of terminal connection portions extending from the terminal body, and the electric wire assemblies include connection terminals connected to end portions of electric wires, the connection method comprising:

providing each of the connection terminals with a pair of fastening caulking pieces;

providing each of the terminal connection portions with a pair of fastened caulking pieces;

folding free ends of open end portions of the fastened caulking pieces inward respectively to form folded portions and a space that extends between the folded portions such that the free ends are space away from each other;

deforming the pair of the fastening caulking pieces so that free ends of the pair of the fastening caulking pieces enter the space;

crushing the pair of fastening caulking pieces and the pair of fastened caulking pieces after the free ends of the fastening caulking pieces enter the space; and

maintaining separation between each of the terminal connection portions and the electric wire upon connecting the terminal fitting and the electric wires through the connection terminals.

2. The connection method for the terminal fitting according to claim 1 , further comprising:

forming, before the deforming the pair fastening caulking pieces, and before the crushing the pair of fastening caulking pieces and the pair of fastened caulking pieces, a retention space in each of the connection terminals by the fastening caulking pieces that is configured to receive the fastened caulking pieces; and

inserting, before the deforming the pair fastening caulking pieces, and before the crushing the pair of fastening caulking pieces and the pair of fastened caulking pieces, one of the terminal connection portions into the retention space so that the open end portions of the pair of the fastened caulking pieces face to the same side as the open end portions of the pair of the fastening caulking pieces to thereby make the connection terminal retain the terminal connection portion.

3. The connection method for the terminal fitting according to claim 2 , further comprising:

providing the fastening caulking pieces with rotation regulation faces; and

crushing the pair of fastening caulking pieces and the pair of fastened caulking pieces includes regulating rotation of the terminal connection portion around an axis extending in an insertion direction of the terminal connection portion by abutting the fastening caulking pieces against the fastened caulking pieces inserted into the retention space.

4. A connection structure for a terminal fitting comprising:

the terminal fitting including a terminal body and a plurality of terminal connection portions extending from the terminal body; and

connection terminals connected to end portions of electric wires,

wherein each of the connection terminals includes a pair of fastening caulking pieces,

wherein each of the terminal connection portions includes a pair of fastened caulking pieces, the pair of fastened caulking pieces include respective end portions that are folded inward to form folded portions that include free ends that are spaced away from each other by a space that extends between the folded portions, and the space is configured to receive respective free ends of end portions of the pair of fastening caulking portions as the pair of fastening caulking pieces are caulked with the pair of the fastened caulking pieces,

wherein the pair of the fastening caulking pieces are caulked with the pair of the fastened caulking pieces after the free ends of the pair of the fastening caulking pieces enter the space, and

wherein each of the terminal connection portions is spaced away from the electric wire and the terminal fitting is connected to the electric wires through the connection terminals.

5. The connection structure for a terminal fitting according to claim 4 , wherein each of the connection terminals includes an electric wire connection portion that is spaced away from the pair of fastening caulking pieces.

6. The connection structure for a terminal fitting according to claim 4 , wherein each of the connection terminals includes an electric wire connection portion, and each of the connection terminals terminates at one end at the electric wire connection portion and terminates at an opposite end at the pair of fastening caulking pieces.

7. The connection structure for a terminal fitting according to claim 4 , wherein

each of the connection terminals includes a pair of conductor caulking pieces caulked and connected to a conductor of the electric wire, and a pair of coating caulking pieces caulked and connected to a jacket of the electric wire, and

the pair of fastening caulking pieces are space away from each of the pair of conductor caulking pieces and the pair of coating caulking pieces.