The cold heading machine is a product that shapes the billet into a certain shape at normal temperature. With the continuous development and progress of production technology, automatic cold heading machines have been widely used in the manufacture of automobiles and mechanical parts.
I. Overview
The cold heading machine is a product that shapes the billet into a certain shape at normal temperature. With the continuous development and progress of production technology, automatic cold heading machines have been widely used in the manufacture of automobiles and mechanical parts. The equipment is fully automated to complete batch professional production of nuts, nuts and other double-click standard mold parts, feeding from rollers, cutting in turn, angle punching and forming, completed in one machine, eliminating the time-consuming and expensive annealing process. The stations are arranged horizontally, the main transmission is a secondary transmission, the main slider is driven by a pressure toggle structure, and the connection between the flywheel and the transmission shaft uses an air pressure friction clutch.
One of our factory's six sets of cold pier machines is equipment imported from the former Soviet Union in the 1950s and is a special production equipment for aircraft rivets. In the early 1970s, the electrical control system was transformed into a thyristor DC speed control system. It has been in service for more than 30 years. The motor commutator is seriously worn out and the control box components are seriously aging, which can no longer guarantee the processing accuracy requirements. After analysis, it was decided to use the variable frequency speed control intelligent control system for transformation.
2. Working principle
The method of forging the top of the bar or wire at room temperature by thickening. Cold heading is mainly used to manufacture bolts, nuts, nails, rivets and steel balls. The forging material can be copper, aluminum, carbon steel, alloy steel, stainless steel and titanium alloy, etc., and the material utilization rate can reach 80 to 90%. Cold heading is mostly carried out on a dedicated cold heading machine, which is convenient for continuous, multi-station and automated production. On the cold heading machine, the processes of material cutting, heading, accumulation, forming, chamfering, thread rolling, diameter reduction and trimming can be completed in sequence. The production efficiency is high, which can reach more than 300 pieces/min, and the diameter of the largest cold heading workpiece is 48 mm. The bar material is automatically fed into a certain length by the feeding mechanism, and the cutting mechanism cuts it into blanks, and then is sent to the accumulation pressure forming and punching station by the clamp conveying mechanism for forming.
3. System configuration
Schematic diagram of frequency conversion speed regulation system
The speed regulating potentiometer (R) is connected to the external given adjustment input point (10V, AI1, AGND) of the inverter, and the output frequency of the adjustment inverter is changed within the range of 0-50Hz, so as to realize the stepless speed regulation of the inverter motor ; Connect the digital display meter on the control cabinet panel to the output frequency point (DO, COM) of the inverter, and dynamically display the motor speed on the digital display meter; connect the alarm light to the relay output point (TA, TC) of the inverter ), alarm when the inverter works abnormally.
Schematic diagram of intelligent instrument control system
Set the total number of processed parts on the counter panel; connect the NPN type proximity switch (SQ) at the signal input points (9, 12, 14) of the counter. After each part of the cold pier machine is processed, the proximity switch sends a signal to the counter, which is displayed on the display. While displaying the number of parts processed, the counter decrements the preset total number of processes by 1. When the preset number is reduced to 0, the auxiliary output normally closed contacts (3, 4) are opened, making the intermediate relay KA1 de-energized. The device stops running. In order to prevent the data set by the counter from being changed by others during automatic processing, a key switch (SA1) is connected to the counter key protection input points (14, 15). After the operator sets the relevant parameters, the counter can be turned by turning SA1. All keys on the operation panel are locked and protected.
When the processed workpiece reaches the preset value, the equipment automatically stops working and waits for a new task. When the machine needs to be stopped during the processing or the machine is stopped due to a fault, the number of parts processed can be kept for a maximum of 10 years, and can be counted when restarted. The counter can be reset through the operation panel and the buttons on the back, which is easy to operate and maintain.
Four, system advantages
1. Due to the use of frequency conversion speed regulation, the speed can be adjusted steplessly according to the technological requirements of the processed parts.
2. After the frequency conversion control is used, the machine is smooth and has no impact when starting and stopping, which extends the service life of the machine.
3. In the event of motor overload or other abnormal conditions, the frequency conversion protection function acts to ensure the safety of the equipment.
4. Can be used in conjunction with PLC to achieve fully automated processing.
The inverter adopts 6000 series, which has the following characteristics:
l Use motor-specific high-speed 32-bit CPU
l Good low frequency characteristics, torque can be increased automatically
l Real-time current adjustment, good dynamic response
l The digital input and output interface is rich in functions, and the interface function can be defined according to needs
l With 2 analog input, 2 analog output, 1 frequency signal output
l Special grounding design, good electromagnetic compatibility
l Abundant real-time monitoring function of operating parameters to keep abreast of the operating status of the machine
l Perfect fault protection function and power-off storage function
Adopting intelligent reversible preset number counter and proximity switch to realize the display of the number of parts processed. The counter has the following characteristics: the use of switching power supply, large voltage adaptation range, strong anti-interference ability; directly display the actual value, and can set the display effective decimal places; keyboard settings, LCD with backlight display, simple operation; 5 kinds Counting input mode, 4 output modes, automatic reset time is adjustable from 0.01 to 9.99s; use the keyboard lock function to lock the keys that are not needed according to the requirements, to prevent misuse.