摘要 |
PURPOSE: A tool horn of an ultrasonic-wave welding machine is provided to prevent fatigue fracture due to stress concentration while reducing an amplification degree by employing a stepped structure with rounded step portions. CONSTITUTION: A tool horn(50) of an ultrasonic-wave welding machine has a stepped structure whose diameter is reduced regularly toward the distal end. Step portions of the stepped structure are rounded. A round value R of the rounded portions is determined by the following equation, R=(D1-D2)/2, where D1 is a larger diameter and D2 is a smaller diameter. If the tool horn has three steps, a hole is formed from the lateral side of the second step to the end of the third step to pass a coil therethrough. |