High-Efficiency Industrial Metal Melting Furnace for Shaft Quenching HRC50-55 2.5-3mm Hardening Layer

High-Efficiency Industrial Metal Melting Furnace for Shaft Quenching HRC50-55 2.5-3mm Hardening Layer

1. User requirements

2. Equipment Selection, Composition and Design Requirements

 Selection Composition: Based on the requirements proposed by your company, we recommend

the following complete set of induction hardening equipment (induction power supply power of

200kW, working frequency of 8-30KHZ), including the following specific equipment:

3. Operation process: The equipment moves the workpiece up and down for scanning

quenching.

Quenching process: It can be loaded manually or by robot . 1. Adjust the mobile transformer

coil to the heating center of the product, use the edited program to start automatic heating,

adjust the corresponding power according to the temperature speed during heating, and when

the heating is finished, stop heating, delay cooling, reset the upper and lower servos,

and the processing is completed. → Take away the workpiece.

Design requirements: The equipment is required to have automatic mode and manual mode.

The specific requirements are as follows:

1) The machine tool adopts a vertical machine tool structure. The system has manual

and automatic functions, and the workstation can be rotated, raised and lowered .

2) The power supply start and stop must have two modes: "manual control" and "remote control" .

3) Power supply oscillation frequency 8-30KHZ , rated power 200KW .​

4) The repeat positioning accuracy requirement of the moving platform of the quenching machine

tool transformer is ≤0.05mm .

5) The entire set of equipment must have manual and automatic operation functions, and the

equipment control panel must have an adjustable speed function. The equipment is also

required to have arbitrary programming and storage functions, and different processing

parameters can be set according to the process requirements of different workpieces .

The control system must have a password locking function to prevent unauthorized personnel

from modifying the process parameters.

6) Color of the whole equipment : The factory default shall prevail . Safety-related warning

colors shall be implemented in accordance with the corresponding national safety standards.

The overall sense is strong, easy to debug and maintain, and the layout of the oil pipe,

gas source and power supply line is required to be reasonable, neat and beautiful; the

transmission device needs to take necessary dustproof measures.

4. Induction Heating Power Supply

4.1 Technical parameters

4.2 The control part of the equipment: mainly composed of power supply, regulator,

phase shift control, protection circuit, phase sequence adaptive circuit, start-up calculation

circuit, inverter frequency tracking, inverter pulse formation, pulse amplification and

pulse transformer. Its core components adopt high-performance, high-density, large-scale

special ASIC-2 integrated circuits produced in the United States, so that the internal circuits

except the regulator are all digitized, and the rectifier trigger part does not require any

adjustment, and has the characteristics of high reliability, high pulse symmetry, strong

anti-interference performance, fast response speed, etc., and because of the phase sequence

adaptive circuit, no synchronous transformer is required, so the work of adjusting the phase

sequence and synchronization is eliminated during on-site debugging. It is only necessary

to connect the gate line of the transistor to the corresponding terminal of the control board,

and the rectifier part can be put into operation.

4.3 Starting mode of the sensor: The starting mode of the sensor is sweep frequency

zero-voltage starting, which means that during the starting process of the sensor, the load

voltage and current gradually increase from zero, so there is no current impact on the

power grid. The starting circuit is equipped with an automatic repetitive starting circuit,

which makes the success rate of starting 100 % . The frequency tracking circuit adopts the

average value sampling scheme, which improves the anti-interference ability of the inverter.

4.4 Inverter trigger: It adopts sweep frequency zero-voltage soft start, which only needs to

take one medium frequency voltage feedback signal, and does not need the current signal

on the high frequency capacitor in the slot circuit. It is essentially equivalent to the

self-excitation circuit, which belongs to the average value feedback circuit. Since no starting

circuit is required to be added to the main circuit, no pre-magnetization or pre-charging

starting process is required, so the main circuit is simplified and the debugging process is simple.

4.5 Voltage and current limiting circuit: To protect the IGBT, once the voltage and current of the

IGBT exceed the rated value, the trigger angle of the transistor on the rectifier side is immediately

adjusted to automatically limit it to the rated value.

4.6 All control circuits are on one printed circuit board, greatly reducing faults caused by external

contact connections .

4.7 The parameters of key electrical components are established through computer simulation

and proved by experiments to be more accurate than those of classical methods . The method

design has higher accuracy and reliability.

4.8 Sensor protection circuit

4.8.1 Overcurrent and cutoff protection circuit :

The cut-off value is generally set to 105% of the rated current , and the overcurrent value is

generally set to 110% of the rated current . When the DC current reaches 1.05 times the

rated current, the current signal taken from the current transformer is reversed by the inverter,

and the rectifier trigger pulse is pulled back. That is, the pulse trigger angle is changed to

reduce the current and play a role in cutting off the current. When the DC current reaches

1.1 times the rated current, the pulse trigger angle is pulled to 150 degrees, and the

high-frequency power supply automatically shuts down. At the same time, the overcurrent

indicator light is on to send out an alarm signal.

4.8.2 Overvoltage and cut-off voltage protection circuit

The cut-off value is generally set to 105% of the rated voltage , and the overvoltage value

is generally set to 110% of the rated voltage . When the high-frequency voltage reaches

1.05 times the rated voltage, the voltage signal taken from the high-frequency voltage

transformer is reversed by the inverter, and the rectifier trigger pulse is pulled back.

That is, the pulse trigger angle is changed to reduce the voltage and play a role in

cutting off the voltage. When the high-frequency voltage reaches 1.1 times the rated

voltage, the pulse trigger angle is pulled to 150 degrees, and the high-frequency power

supply automatically shuts down. At the same time, the overvoltage indicator light is on to

send out an alarm signal.

4.8.3 Undervoltage and phase loss protection circuit

The high-frequency power supply control circuit is equipped with undervoltage detection

protection. When the incoming line voltage is lower than 10% , the undervoltage protection

circuit blocks the rectifier trigger pulse, so that the high-frequency power supply cannot be

started. When the three-phase AC input is missing, in addition to blocking the rectifier trigger

pulse, it also drives the indicator light to sound an alarm.

4.8.4 Water shortage protection

Connect the normally open contact of the water pressure relay in series with the high-frequency

power supply control circuit. When the water pressure is less than 1.5kg/cm3 , the control

circuit cannot be energized and the high-frequency power supply cannot be turned on, thus

playing a role in water shortage protection.

4.8.5 Sensor manufacturing process: The sensor coil is made of T2 oxygen-free copper

tube after annealing , pickled, saponified, and sprayed with 167 type high temperature

resistant , moisture-proof and high-strength insulating paint.

3.9 Suppliers and origins of main power supply components: