The impact of temperature control on winding in a fully automatic winding machine

Analysis of the Impact of Temperature Control on Winding Quality in Fully Automatic Winding Machines

1. Introduction

In modern electronic manufacturing, fully automatic winding machines are key equipment for coil production, and their performance directly determines the quality of electronic components such as inductors, transformers, and motors. Temperature, as an important parameter in the winding process, has a profound impact on the quality of winding. This article will delve into the impact mechanism of temperature control on the winding process, analyze various problems that may be caused by temperature fluctuations, and propose effective methods for optimizing temperature control.

2、 The Influence of Temperature on the Characteristics of Winding Materials

2.1 Temperature dependence of insulation performance of enameled wire

As the main material for winding, the physical properties of the insulation coating of enameled wire are extremely sensitive to temperature changes. When the ambient temperature is too high (usually exceeding 150 ℃), the molecular structure of the insulating paint begins to relax, leading to a decrease in dielectric strength. Experimental data shows that for every 10 ℃ increase in temperature, the insulation resistance of the paint film may decrease by 30-50%. This change directly increases the risk of inter turn short circuits, especially in high-frequency application scenarios.

On the contrary, in low-temperature environments (below 5 ℃), insulation paint will become brittle and hard, and microcracks are prone to occur during the winding process. These microscopic defects may become the starting point of insulation failure in subsequent use. The ideal winding temperature should be maintained between 15-35 ℃, at which point the paint film maintains sufficient flexibility without softening due to overheating.

2.2 Temperature effect on mechanical properties of copper wires

The yield strength and elongation of copper wires vary significantly with temperature. When the temperature increases, the lattice vibration of copper intensifies, and the interatomic bonding force weakens, resulting in a decrease in tensile strength and an increase in ductility. Within the temperature range of 25 ℃ to 100 ℃, the tensile strength of copper wires may decrease by 15-20%. This characteristic directly affects the tension control during winding - at high temperatures, the tension needs to be reduced to avoid excessive stretching, while at low temperatures, the tension needs to be appropriately increased to ensure the tightness of the coil.

3、 The influence of temperature fluctuations on winding process

3.1 Temperature sensitivity of coil geometric accuracy

Temperature changes can cause thermal expansion and contraction of metal components in winding machines. Taking a common aluminum alloy frame as an example, its coefficient of linear expansion is about 23 × 10 ⁻⁶/℃, which means that a 1-meter-long component will experience a length change of 0.23mm when the temperature changes by 10 ℃. This small size variation will accumulate in multiple layers of winding, ultimately causing the outer diameter deviation of the coil to exceed the tolerance range. Precision winding requires environmental temperature fluctuations to be controlled within ± 2 ℃.

3.2 Temperature drift problem of tension system

The magnetic output of the electromagnetic tensioner in modern winding machines is negatively correlated with temperature. In uncompensated systems, for every 10 ℃ increase in ambient temperature, tension may decrease by 8-12%. This kind of drift can lead to inconsistent tightness of the winding, which can affect the consistency of the inductance or cause the coil to collapse. Advanced temperature compensation algorithms can control this impact within ± 2%.

3.3 Temperature window for adhesive curing

The epoxy resin used in the impregnation process is extremely sensitive to curing temperature. A typical medium temperature curing resin has a curing time of 60 minutes at 85 ℃, but needs to be extended to 120 minutes at 65 ℃. A temperature deviation of 5 ℃ may result in a curing degree difference of up to 20%, directly affecting the mechanical strength and weather resistance of the coil. Segmented temperature control technology ensures that the temperature gradient in the curing zone does not exceed ± 3 ℃.

4、 Key technologies for temperature control

4.1 Multi regional temperature monitoring system

Modern winding machines adopt distributed temperature sensing networks, and sensors are usually arranged at the following key points:

-Wire spool area (monitoring incoming material temperature)

-Tensioner area (controlling frictional heat)

-Winding head area (detecting high-speed friction temperature rise)

-Curing furnace area (multi-stage temperature monitoring)

This arrangement can achieve a monitoring accuracy of ± 0.5 ℃, providing a data foundation for closed-loop control.

4.2 Adaptive Temperature Control Algorithm

The advanced control algorithm based on PID can dynamically adjust the heating/cooling output. Experimental data shows that using fuzzy PID control reduces overshoot by 40% and stability time by 35% in step response compared to traditional PID control. For servo winding heads with rapid instantaneous temperature rise, predictive control algorithms can compensate for the expected temperature changes in advance.

4.3 Thermal isolation and heat dissipation design

The following thermal management measures are adopted for key components:

-Install insulation layer between servo motor and winding head

-High heat generating components are equipped with forced air cooling (adjustable wind speed range of 0.5-3m/s)

-Sensitive electronic components use constant temperature bath technology

These measures can control the temperature rise of key parts within the ambient temperature+15 ℃.

5、 Handling strategies for temperature anomalies

5.1 Establishment of early warning mechanism

Suggestions for setting up a three-level warning system:

-Level 1 warning (yellow): Temperature deviation from set value ± 3 ℃

-Level 2 warning (orange): Continuous deviation from ± 5 ℃ for more than 10 minutes

-Level 3 warning (red): instantaneous temperature exceeding ± 10 ℃ or continuous exceeding ± 8 ℃

Each level of warning corresponds to different disposal processes, from automatic adjustment to shutdown protection.

5.2 Dynamic compensation of process parameters

The automatic compensation strategy for abnormal temperature includes:

-The tension decreases at a rate of 0.5%/℃ as the temperature increases

-The winding speed automatically decreases by 5-15% at high temperatures

-The spacing between cables is automatically adjusted based on the coefficient of thermal expansion

These compensations can reduce about 70% of temperature related defects.

VI. Conclusion

The temperature control of fully automatic winding machines is a multidisciplinary topic involving materials science, mechanical engineering, and automatic control. By establishing a precise temperature monitoring network, adopting intelligent control algorithms, and implementing comprehensive thermal management measures, the impact of temperature on winding quality can be minimized. The future development directions include temperature field prediction models based on machine learning and the application of new phase change materials, which will further enhance the stability and reliability of winding processes.