Ultrasonic joining method, ultrasonic joining device and unit joined by ultrasonic joining

Abstract

In an ultrasonic joining method for joining a flange portion of a first member to a portion of a second member, a first horn and a second horn are arranged on the flange portion on a side opposite to the second member, and the first horn is vibrated in a condition that the second horn is biased against the first horn and the first horn and the second horn are pressed against the flange portion such that the flange portion is vibrated while being pressed against the portion of the second member. Because the first horn is vibrated in a condition that the first horn and the second horn are pressed against each other at press-contact portions thereof, vibration of the first horn is transferred to the second horn through the press-contact portions.

1 . A joined unit comprising a first member that has a first portion and a second portion flanged from the first portion at an end of the first portion and a second member, the flanged second portion has a first surface and a second surface joined to a portion of the second member by ultrasonic joining using a horn unit that includes a first horn vibrated by an oscillator and a second horn pressed against the first horn, the first horn and the second horn having projections at substantially uniformed intervals over surfaces that are pressed against the first surface of the flanged second portion for applying vibration to the flanged second portion, wherein
 the first portion of the first member has at least one of a bent portion and an overhang portion, and   the flanged second portion has impressions on the first surface due to the projections of the first horn and the second horn.   
   
   
       2 . The joined unit according to  claim 1 , wherein
 the first portion of the first member has a tubular shape and the first member defines an opening through the first portion and the flanged second portion,   the portion of the second member to which the first surface of the flanged second portion is joined defines an opening, and   the flanged second portion is joined such that the opening of the first member is in communication with the opening of the second member.