Method for connecting an electrical cable to a contact piece
Prior to insertion into the recess of a crimping region, the axial ends of the plurality of electrical strands of the cable are fixed with a clamping tool so that the axial ends of the plurality of electrical strands protrude axially out of the clamping tool and the ends of the plurality of strands protruding axially from the clamping tool are sheared off in the transverse direction with a cutting tool so that a closed end face is produced at the axial end of the strands. The axial end of the plurality of electrical strands is inserted into the recess and the plurality of strands are welded to the contact piece by melting the closed end face arranged in the recess by radiation energy of a radiation directed onto the end face.
1 . A method for connecting an electrical cable including a plurality of electrically conductive strands to a contact piece, comprising:
forming a crimping region including a central recess surrounded at least in part by a crimp tab on the contact piece;
fixing axial ends of the plurality of electrical strands using a clamping tool before the axial ends are inserted into the recess so that the axial ends of the plurality of electrical strands protrude axially out of the clamping tool and shearing off the ends of the plurality of strands protruding axially from the clamping tool in a transverse direction using a cutting tool, to produce a closed end face at the axial end of the plurality of electrical strands, the closed end face being transverse to an axial direction of the plurality of electrical strands;
inserting the axial ends of the plurality of electrical strands into the recess;
pressing the axial ends of the plurality of electrical strands together with the crimp tab to produce an electrical connection; and
welding the plurality of strands to the contact piece by melting the closed end face arranged in the recess by radiation energy of a radiation source directed substantially normal onto the end face,
wherein the radiation source is directed substantially normal to the end face, and wherein, due to adhesive forces, the melted closed end face forms a concave surface.
2 . The method according to claim 1 , wherein the closed end face is arranged axially offset in the recess from an end edge of the crimping region that faces away from the cable.
3 . The method according to claim 1 , wherein the ends of the plurality of strands protruding axially from the clamping tool are sheared off normal to a longitudinal axis of the cable so that the end face is oriented normal to the longitudinal axis of the cable.
4 . The method according to claim 1 , wherein the ends of the plurality of strands protruding axially from the clamping tool are sheared off at an angle to a longitudinal axis of the cable so that the end face is oriented at an angle to the longitudinal axis of the cable.
5 . The method according to claim 4 , wherein a recess is provided in the crimp tab in a region of an end edge of the crimping region to prevent shadowing of the radiation energy at the end face arranged in the recess.
6 . The method according to claim 4 , wherein:
an end edge of the crimping region is chamfered at an angle to the longitudinal axis of the cable; and
the end face is chamfered at an angle steeper than the angle of the end edge.
7 . The method according to claim 1 , wherein the axial end of the strands is pressed in a radial direction before shearing-off.
8 . The method according to claim 1 , wherein a coating on a surface of the contact piece is removed from an area in the crimping region before the crimping.
9 . The method according to claim 1 , wherein a coating on at least one of a surface of the contact piece in the welding region or in a region in front of the end face in the recess is at least partially removed before the welding.
10 . The method according to claim 9 , wherein the coating is removed by the radiation energy.
11 . The method according to claim 7 , wherein the axial end of the strands is pressed to be gas-tight.