Analysis of ultrasonic metal welding faults

Give out heat:

The welding head may experience certain heating phenomena during operation, which is caused by the mechanical loss of the material itself and the heat conduction of the welding component. The standard for determining whether the heating of the welding head is normal is to continuously emit ultrasonic waves for more than half an hour without load (i.e. without contact with the workpiece), and the temperature should not exceed 50-70 ℃. If the heating is severe, it indicates that the welding head has been damaged or the material is unqualified, and needs to be replaced.

Howl:

When the welding head howls during operation, the following reasons should be analyzed:

1. Is the installation screw loose

2. Whether there are cracks on the welding head

3. Whether the welding head is in contact with objects that should not be in contact.

Overload:

When the generator emits an overload alarm, the following steps should be for inspection:

1. No-load test, if the working current is normal, it may be due to the welding head coming into contact with objects that should not be in contact or the parameter adjustment between the welding head and the welding base malfunctioning.

2. When the no-load test is abnormal, the welding head should be first observed for cracks and firm installation. Then, the welding head should be removed and the no-load test should be carried out to eliminate whether there is a problem with the transducer and amplitude converter. Step by step, the problem should be resolved. After ruling out the possibility of malfunctions in the transducer and amplitude converter, remove and replace the new welding head for judgment.

3. Sometimes, there may be situations where the no-load test is normal but cannot work properly, which may be due to changes in the internal sound energy components such as welding heads, resulting in poor sound energy transmission. Here is a relatively simple judgment method: hand touch method. When working normally on the surface of the welding head or amplitude converter, the amplitude is very uniform, and the hand feels as smooth as velvet. When the sound energy transmission is not smooth, there will be bubbles or burrs when touched by the hand. At this time, the elimination method should be used to eliminate the problematic components. When the generator is not working properly, the same situation can occur because normally, when detecting the input waveform of the transducer, it should be a smooth sine wave. This phenomenon can also occur when there are spikes or abnormal waveforms on the sine wave. In this case, another whole acoustic component can be replaced to distinguish.