Numerical control transformation of deep neck press
A11-20A type deep neck press is mainly composed of body, clutch, slider, brake and manipulator. It uses the crank connecting rod as the working mechanism, see for its operating principle. The crank connecting rod mechanism is rigid, so the movement of the slider is mandatory, and the number of strokes per minute of the slider and the movement curve of the slider are fixed. This press is a general-purpose press for sheet stamping. It is suitable for various cold stamping processes, such as shearing, punching, blanking, bending, and wire drawing. Due to its deep throat, it is especially suitable for automobiles, electrical appliances, and motors. Punching, blanking, line drawing and other stamping work of large and thin plate parts in industries such as, instrument and other industries.
In actual production, it has the following problems: ①Poor manual positioning accuracy. “Operators have high labor intensity and are prone to injuries and disability. Safety cannot be effectively guaranteed. It is not suitable for small batch processing of different varieties. Product flexibility is poor; ④The defective rate is high, and the production efficiency is low. This affects the development of productivity. The use of advanced numerical control devices has become the general trend of deep neck press processing technology in China. Increase the numerical control rate of deep neck presses. There are two ways: one is to purchase a new CNC deep-neck press, and the other is to convert an ordinary deep-neck press into a CNC deep-neck press. According to China’s current economic situation, spend a lot of money to replace a new CNC type Deep-neck press is impossible, and at the same time it is a big waste for the original ordinary deep-neck press, while the CNC transformation of ordinary press is both economical and quick. It is in line with China’s national conditions and is an improvement. Number of deep-neck presses) Steps to achieve) According to the formula, analyze the current sampling point of the zero sequence voltage and calculate the amplitude of the zero sequence voltage!.) Determine whether it is satisfied!> 2x15V, as whether there is a ground fault If this condition is not met, continue to step 1). If this condition is met, start sampling and analysis of the zero-sequence current of each outgoing line.) Use the formula to calculate the zero-sequence active power of each outgoing line as the outgoing line number ).) Comparing the zero-sequence active power of each line, the largest one is the single-phase grounded line.
4 Conclusion By analyzing the characteristics of the zero-sequence current when single-phase grounding occurs in the compensation system, the principle of line selection based on the active component of the zero-sequence current is proposed. The essence is to find the algebraic value of the largest zero-sequence active power mutation. It also analyzes the advantages of the recursive DFT algorithm and the algorithm steps to realize the principle of the line selection. This algorithm only uses the real and imaginary parts of the signal, avoiding any calculations about the phase relationship. The calculation is small, the calculation speed is fast, and the real-time performance is good. Therefore, it is a more effective method for the compensation system to judge a single-phase ground fault.
2 Refer to the numerical control transformation of the deep neck press. The deep neck press mainly includes: OP numerical control unit operation panel, MCP machine tool panel, ENC numerical control unit, DI/0 input and output module, X-axis and Y-axis stepper motors and Drive, X-axis and Y-axis three-phase hybrid stepping motor, the main motor of the press is three-phase 380V), electromagnet clutch YA (model MQ1-5131, 380V/50HZ) and some X, Y axis positive and negative limits It is composed of position switch, emergency stop switch and safety photoelectric switch.
The structure of the CNC system of the deep neck press is shown: 1-0P operation panel 2-MCP press machine tool panel; 3-ENC numerical control unit; 4-DI/0 input and output module; 5-machine control box; 6-main motor; 7-YA electromagnetic clutch; 8-emergency stop switch, limit switch, photoelectric safety device; 9-X-axis and Y-axis stepping motor driver; 10-X-axis and Y-axis stepping motor working principle is based on processing needs The program is input to the CNC unit ENC through the operation panel, or programmed on the computer and simulated running without error, and networked with the CNC unit ENC through the intelligent communication interface, and the instructions or data are sent to the CNC unit. According to the requirements of the program, the numerical control system controls the main motor M and the electromagnetic clutch YA after information processing and distribution, and controls the X-axis and Y-axis to move several minimum displacements to realize the relative movement of the press block and the workpiece. Processing of finished products. ) Refer to the main motor control principle as shown, the main motor control is divided into manual control and automatic control. ) Manual control Manual control is generally used for maintenance and debugging or the processing of a single component. Close the knife switch “G. At this time, the transfer switch is placed in the manual position, and the key switch SA1 is closed. Press the start button SB2, KM1 sucks and protects itself. The main motor M starts to rotate, press the manual button SB3 or the foot switch SF, the intermediate relay KA pulls in, the electromagnetic clutch YA connects to the AC380V power supply, the pressing block slides down, and the parts processing starts. SB1 is the stop button.
During normal processing, the switch SW1 is placed in the automatic state. When the processing starts, the CNC unit ENC issues an instruction, 1 is closed, the contactor KM1 is powered on, the main contact is closed, and the main motor starts to rotate. When punching is needed, Wang 3- issues an instruction, the intermediate relay 3 is closed, and then KA is closed, the electromagnetic clutch YA is turned on, the pressing block is activated, and the processing of the part is started. The NC issues an instruction when it needs to stop. 0 and 2 are closed, KM1 and KA are disconnected, and the main motor M and the electromagnetic clutch YA are cut off at the same time. The 0, 1, 2, and 3 intermediate relays are controlled by numerical control programming, and they are all connected in parallel with freewheeling diodes to prevent the ENC numerical control unit from being burned out by the reverse high voltage at the moment of the relay power failure.
(3) Hybrid stepping motor feed system) The deep neck press feed transmission part is modified to remove the mechanical transmission mechanism of the original machine tool, and use a stepping motor to drive the screw through a gear mechanism to reduce the speed to drive the workpiece to move longitudinally and laterally. As shown, the longitudinal feed is the X-axis drive, the stepping motor 3 is fixed on the chassis, and the screw is driven by the gearbox 2 to drive the workpiece to move longitudinally. The Y-axis drive, that is, the lateral feed, is that the stepping motor 1 directly drives the lead screw, thereby driving the lateral movement of the workpiece. The longitudinal feed adopts a deceleration mechanism, which can achieve the required pulse equivalent, and can also meet the structural requirements and increase the torque.
The structure of the feed system indicates the gearbox of 1-Y-axis stepper motor; 3-X-axis stepper motor; 4-bed; 5-worktable) select the three-phase hybrid stepper motor produced by Bergerlahr, Germany, and The driver applies the AC servo principle to the stepper motor system. The stepper motor has absorbed the advantages of two-phase and five-phase motors, and its matching drive adopts the working mode of AC servo motor drive. This motor system completely solves the low-speed crawling, resonance zone, loud sound and high speed of traditional stepper motors. Shortcomings such as small torque, so it is called a stepping motor system with AC servo motor operating characteristics.
Refer to the stepping motor drive control schematic diagram, the AC380V power supply is isolated and stepped down by the transformer TB into AC220V as the power supply voltage of the stepping motor driver connected to the L and N terminals, the CNC unit CP+, CCW+ output pulse sub-control driver WD3- The output pulse and output direction of 007, U, V, W are connected to the angular connection winding of the stepper motor. The PE terminal of the driver and stepper motor requires reliable grounding.
Stepper motor winding wiring and current waveform refer to and shown, Baigla Company applies the AC servo motor driver principle to the stepper motor driver, the input AC220V is rectified to produce DC325V and pulse width modulation into 325V stepped sinusoidal current Waveform, each step corresponds to one step of the motor’s rotation. The motor speed is changed by changing the frequency of the output current of the driver, and the number of steps that are output does indeed go through the angle of the motor. As shown, the current flowing through each phase winding is a stepped sinusoidal current. Due to the use of a sinusoidal stepped current drive, the current change corresponding to each step of the motor is very small, so there will be no low-speed crawling, resonance, loud noise and other undesirable phenomena. The operating characteristics are almost the same as AC servo motors. Only 3 power lines are used between the motor and the drive, and there is less possibility of wiring errors as with AC asynchronous motors. The driver circuit board adopts three-proof treatment, with overheating, overvoltage, undervoltage, motor phase short circuit and overcurrent protection functions. The drive has a half-current function. When the stepper motor is used, please subscribe to the 2002 Coal Mine Electromechanical Magazine bookmark1 = this magazine is self-published, and the order will be sent upon request. Address: No. 1, Tianyaoqiao Road, Shanghai, 200030, telephone (021) After being charged and standing still at 100, the output current of the drive will automatically be reduced to 60 of the rated output current to prevent the motor from heating up.
In short, the three-phase hybrid stepping motor drive system has fully demonstrated a series of advantages such as high positioning accuracy, fast response speed, large torque, small motor heating, and no resonance zone in the actual production application.
(4) Emergency stop limit and other protection devices (enc-numerical control unit for safety protection devices such as emergency stop limit; SB6-emergency stop button; SB5-start button; SB4-overtravel release button; S01, S02, S03, S04 -X-axis and Y-axis positive and negative limit switch; ZCZ-press block work detection switch 1) The numerical control system is equipped with soft and hard limit protection. The soft limit alarm is generated by setting the maximum and minimum coordinate values of each axis of the machine tool to move in the machine coordinate system. The inside of this area is called the working area and the limit is set inside the hard limit. The travel limit of the hard limit protection is formed by the travel switch. Once the travel switch is pressed, the feed drive power will be cut off immediately and the CNC system will be notified to generate an overtravel alarm. ) If an abnormal situation occurs during the processing, pressing the emergency stop button SB6 will immediately cut off all driving power and realize an emergency stop. After the fault is eliminated, the emergency stop must be manually released before the work can continue. ) ZCXZCY is the working point of the deep-neck press. ZCZ is the pressure block detection device, which is used to process complex graphics through programming and the electromagnetic clutch YA.
3 Conclusion The deep-neck press, which has been transformed by numerical control, has the main advantages: the system is flexible and reliable. It has the ability to store input information, and can input common processing programs into memory at one time and call them at any time. The numerical control unit uses a computer as a control component with less hardware, which reduces the failure rate of system components and improves reliability.
System software control, easy to expand, and strong adaptability. Different parts can be processed as long as the program is changed, and the processing of complex patterns can be carried out.
With self-diagnosis capability, easy maintenance. The system has a diagnostic program, which can easily find out the type of failure and the location of the failure and the downtime of the failure.
Program editing is convenient. You can add, delete, and modify the debugging program on site, or you can program and simulate running on the computer, and transmit it to the CNC unit by communication.
can realize fully automated processing. During the processing, only need to clamp the processed plate and press the start button on the machine tool. The remaining processing process can realize fully automated processing, which greatly reduces the labor intensity of the operators and is welcomed by the on-site workers.
can realize safety protection. If someone strays into the processing area during the processing, the CNC system can automatically cut off the power supply to achieve safety protection and ensure the safety of production.
Save money. Compared with purchasing a new CNC deep neck press, it can save a lot of money.
The control principle is more complicated, requiring the maintenance personnel to have wide knowledge and strong hands-on ability.
requires highly familiar and trained programming and operating personnel.
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