Parameter example (45 steel shaft, diameter 25mm, quenched layer 1.2mm):
Frequency: 200-300 kHz
Power: 10-15 kW
Heating time: 2-3 seconds
Cooling: polymer quenching solution spray
5.3 Annealing and Stress Relief
Internal stress elimination or softening treatment after metal processing, such as cold heading screws and stretched wire. Use lower frequencies (50-200 kHz) to achieve heat transfer.
Parameter example (stainless steel wire, diameter 4mm, annealed):
Frequency: 100 kHz
Power: 6 kW
Heating speed: continuous wire feeding, temperature 900-1000 ℃
5.4 Hot assembly (shrink fit)
Bearings, gears, sleeves and other parts are heated and expanded before being assembled onto the shaft, and after cooling, they form an interference fit. Induction heating has a fast speed and only heats the outer ring, without affecting the inner ring or shaft.
Parameter Example (Inner Ring Heating of Bearing, Outer Diameter 80mm):
Frequency: 10-30 kHz (requires the use of a lower frequency generator, SINUS series with a minimum frequency of 50kHz is suitable for larger sizes)
Power: 10 kW
Heating time: 20-40 seconds

Maintenance and troubleshooting
6.1 Daily Inspection
Check project cycle standards
The cooling water flow rate meets the model requirements daily
The water temperature is 18-25 ℃ per day
Is there any leakage in the waterway? No leakage per day
The power cabinet fan runs normally every week without any noise
Coil insulation has a weekly ground resistance greater than 1M Ω
Clean the water filter monthly without any blockage
The terminals are tightened quarterly without any looseness
6.2 Common faults and countermeasures
Troubleshooting steps for possible causes of fault phenomena
There is no response when starting up, and the main power supply is out of phase; Fuse blown, check input voltage; Replace the fuse
Trip overcurrent during operation; Check whether the coil touches the workpiece during coil short circuit inspection; Reduce power for trial operation
Insufficient heating power, frequency deviation from resonance point; Adjustment of coil turns or parallel capacitance due to poor matching of coils; Consult the manufacturer
Alarm for high water temperature and insufficient cooling water flow; High temperature washing filter; Increase the capacity of the water chiller
Power fluctuation and voltage fluctuation in the power grid; Install a voltage regulator for changes in workpiece clearance; Fixed workpiece position
Profibus communication fault cable breakage; Station address conflict check bus terminal resistance; reconfigure
6.3 Coil maintenance
The coil is a vulnerable component, and after long-term use, its efficiency may decrease due to overheating deformation, oxidation, or scaling inside the copper tube. Suggestion:
Check the appearance of the coil every 500 hours, and replace it promptly if there is any deformation.
Internal water flushing and descaling of the coil: weakly acidic cleaning agents can be used for cyclic flushing (pay attention to discharge after neutralization).
The insulation between the coil and the workpiece (such as wrapping glass ribbon) should be intact to prevent ignition.
Integration and Automation
The SINUS series supports multiple fieldbus interfaces, making it easy to integrate into automated production lines
Profibus DP: Standard optional, can remotely set power, time, read status and alarm.
Profinet: Suitable for industrial Ethernet environments such as Siemens.
Other interfaces: EtherNet/IP, Modbus TCP, etc. can be customized.
Analog interface: 0-10V or 4-20mA control power, combined with infrared thermometer to achieve closed-loop temperature control.
Typical integration solution:
PLC sends commands such as "start heating" and "power setting value" through Profibus.
The generator outputs to the coil and simultaneously collects signals from the infrared thermometer.
After reaching the set temperature, the PLC controls the workpiece to move or spray for cooling.
The heating process data can be uploaded to the MES system for traceability.
Safety precautions
Electric shock hazard: There is high voltage (hundreds to thousands of volts) inside the generator, and non professionals are strictly prohibited from opening the cabinet door. After the power is cut off, wait for at least 5 minutes until the filter capacitor discharges completely before repairing.
Burn hazard: The temperature of the workpiece and coil is extremely high after heating, and insulated gloves or robotic arms should be used during operation.
Electromagnetic field: High frequency and strong magnetic fields pose a fatal danger to users of pacemakers, and warning signs should be set up in the work area. The operator should maintain a distance of at least 500mm from the coil.
Cooling water leakage: If the water cooling system leaks, it may cause an electrical short circuit. Circuit breakers with leakage protection function should be used, and leakage detection sensors should be installed.
Fire prevention: The heating area should be kept away from flammable materials and equipped with fire extinguishing equipment.
