Some factors affecting the quality of hollow voice coil
Due to its own characteristics, hollow coils have been widely used in voice coils in the electro-acoustic industry, deflection coils in precision instruments, combined coils in micro motors, and micro coils in sensors. Self-adhesive enameled wire has increasingly become the main wire type used in the coil winding process due to its excellent heat resistance, insulation, adhesion durability, easy molding, and simple winding process
In addition, the coil needs to maintain a certain shape during use, which requires that the bonding strength of the coil does not decrease with time in different environments. In the winding process of the winding machine, especially for enameled wires below 0.1mm, the phenomenon of scattered, stacked, and loose wires often occurs. The factors affecting the winding quality are mainly from enameled wires, winding machine equipment and tooling consider.
Hollow coil winding machine
The surface paint layer of the self-adhesive enameled wire is divided into two parts: the primer layer and the self-adhesive layer. The primer layer acts as an insulating layer and protects the inner copper core. The self-adhesive layer mainly plays the role of bonding and forming. Self-adhesive enameled wire is mainly divided into hot air and alcohol solution according to the bonding method. The mainstream self-adhesive method is mainly hot air.
For thermal curing methods such as hot air and heating furnace, the temperature level, temperature gradient and temperature uniformity of the heating process have an important impact on the bonding performance of the winding. When curing, refer to the curing temperature and curing time recommended by the manufacturer. If the temperature is low or the heating time is not enough, the bonding may not be firm; and if the temperature is too high, the enameled wire and even the coil may be damaged.
In the actual winding process of the winding machine, the hot air temperature is related to the ambient temperature, and there is often a gap between the set temperature and the actual outlet temperature. The temperature sensor can be used to measure the air outlet temperature in real time to prevent the hot air temperature from being too high or too low. Of course, it may take several attempts to achieve satisfactory results.
Tension control: The tension of the wire during the winding process is non-linear, so a tensioner is required to control the tension of the wire to fluctuate in a relatively small range to ensure that the coiled wire meets the requirements. The process of winding the coil of the equipment is relatively fast, so the accuracy of the cable axis is relatively high. If the accuracy is not achieved, it may cause problems such as jumpers and excessive line spacing.