The safety system of the armature winding machine is based on the design of the loop winding machine. Through field inspection and conversation with the operator, it is found that the worker puts the unwound iron core into the three rolling wheels when operating the loop winding machine. The specific operation is:
1) Open the dovetail lock bar of the wire storage ring body, separate the open movable section of the wire storage ring, and let the center vacancy of the unwound iron core pass through the opening part of the wire storage ring.
2) Lock the lock bar and step on the foot switch to rotate the thread storage ring. The maximum speed can reach 700 r/min. The thread end in the winding core must be pulled to the other side by hand.
Because the speed of the armature winding machine is too fast, workers need to operate at a very fast speed and skillful movements. At this time, there are two kinds of finger injuries:
1) The broken enameled wire will insert the finger and cause finger injury.
2) The high-speed copper wire will press on the fingers, the skin of the finger will go out in the lighter, and the finger will be broken in the severer.
1. The working principle of the inverter
The working principle of AC frequency converter is: frequency conversion technology is a technology that changes the frequency of the power supply through the frequency converter, thereby changing the speed of the AC asynchronous motor. The AC to DC conversion is performed through the inverter first, and then the DC to AC conversion is performed through the inverter to control the speed of the AC motor. The Guangri JG series toroidal armature winding machine in this project controls the inverter by controlling the analog voltage input to the inverter, and then controlling the frequency of the inverter output power, so that the speed of the AC motor changes with the change of the output power frequency.
2. Three-phase asynchronous motor variable frequency speed regulation
The speed formula of the three-phase asynchronous motor is
n=60 f/p (1-s), (1)
In the formula, n is the speed of the three-phase asynchronous motor, f is the power supply frequency, p is the number of pole pairs of the motor, and s is the slip rate.
From equation (1), we can see that changing f, p and s can achieve the purpose of changing n.
The torque of an asynchronous motor is produced by the interaction between the magnetic flux of the motor and the current flowing in the rotor. At the rated frequency, if the voltage is constant and the frequency is reduced, the magnetic flux will be too large and the magnetic circuit will be saturated. The motor will be burned. Therefore, the frequency and the voltage should be changed in proportion, that is, the output voltage of the frequency converter is controlled while changing the frequency, so that the magnetic flux of the motor is kept constant, and the phenomenon of weak magnetic field and magnetic saturation is avoided. Since general inverters generally use V/f control, that is, variable voltage and frequency conversion (VVVF) speed regulation, changing the frequency and voltage is the optimal motor control method. Frequency conversion speed regulation is a speed regulation method that changes the synchronous speed of the motor by changing the frequency of the motor's stator power supply. Its characteristics are:
1) High efficiency, no additional loss during speed regulation.
2) It has a wide range of applications and can be used for cage asynchronous motors. 3) Large speed range, hard characteristics and high precision. Therefore, this research chooses the frequency conversion speed regulation method.
3. The basic composition of the armature winding machine system
At first, the system was mainly composed of 51 single chip microcomputer minimum system, photoelectric isolation relay module and infrared digital obstacle avoidance sensor. The smallest system of 51 single-chip microcomputers includes: power supply, external crystal oscillator circuit, reset circuit and STC89C52 chip. After practice, the logic control module is more accurate. The protective device is mainly composed of infrared digital obstacle avoidance sensor, logic control module and relay speed reduction module.
When the operator's hand enters the dangerous area, the infrared digital sensor will feed back the detected signal to the logic control module. The logic control module outputs the corresponding control signal to the relay speed reduction module according to the feedback signal. The relay speed reduction module will have different resistance values The resistor is serially connected into the pedal speed control loop to reduce the speed of the winding motor, thereby playing a safety protection role.
4. Armature winding machine system device
The armature winding machine system device mainly consists of three parts, namely the control system box, the sensor arrangement on the workbench and the pedal speed control, as shown in P1.
In P1, 1: armature winding machine workbench; 2: control box; 3: the rack; 4 : wire storage ring; 5: vertical support; 6: first transverse support; 7: second transverse support; 8: chute; 9: sensor guide; 10: pedal governor; 11: infrared sensor; 12: ultrasonic sensor