Technical data

7-2
RL35HWV40/GB/N
O
7768/16279
Elements
7.3 Horn
Any changes to the metallic body of the horn will
affect its vibration characteristics and should not be
performed without consulting the manufacturer!
The horn (3) is the tool that transfers the ultrasonic energy
produced by the converter to the welding object in the form of an
intensive vibration.
Since workpieces come in a variety of forms, horns have to be
adapted to the specific requirements.
The horn is an acoustic body tuned to the resonance frequency.
This accounts for restricted shaping possibilities.
The geometrical form of the horn should be kept as simple as
possible.
Other important factors in addition to the geometrical shape of a
horn are:
1. The horn must be tuned to the resonance frequency of
35'000 Hz (±50 Hz) at 20°C. During operation a tolerance
of +150 Hz / -250 Hz is permitted.
2. For the horn to vibrate correctly it must be designed as far
as possible to move in an axial direction at its transmission
surface.
The aim is to produce pulses on the horn face that act as
far as possible in an axial direction and which can be
transmitted to the welding object.
3. The amplitude of the horn is determined by means of its
design. For the production of horns it is vital to have a
knowledge of the load capacity of various materials.
7.3.1 Horn materials
Horns are manufactured exclusively from specifically high-strength
materials; namely high-strength aluminium, titanium and steel
alloys.
The choice of material depends largely on the intended applica-
tion.
Various factors are crucial for choosing the material:
1. The strength of the horn material in conjunction with the
amplitude to be attained.
2. The surface condition of the material and its related
surface finishing characteristics.
3. The ultrasonic transmission characteristics.
4. The heat conducting characteristics of the horn material.
Allowance must also be made for the fact that horns are subject
3