Numerical control transformation of deep neck press

The A11-20A deep neck press consists of the main body, clutch, slider, brake and manipulator. It is a crank connecting rod as a working mechanism, and its action principle is also referred to. The crank-link mechanism is rigid, so the movement of the slider is mandatory, and the number of strokes per minute of the slider and the motion curve of the slider are fixed. This press is a general-purpose press for sheet metal stamping. It is suitable for various cold stamping processes such as shearing, punching, blanking, bending and wire drawing. It is especially suitable for automobiles, electrical appliances and motors due to its deep throat. Stamping work such as punching, blanking, and wire drawing of large thin plate parts in industries such as meters.

In actual production, it has the following problems: 1 poor precision of manual walking. "Operating workers have high labor intensity and are prone to disability accidents. Safety cannot be effectively guaranteed. It is not suitable for processing small batches of different varieties. The product has poor flexibility; 4 times high product rate and low production efficiency. 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. Two ways: one is to purchase a new CNC deep-neck press, and the other is to convert a common deep-neck press into a CNC-type deep-neck press. According to China's current economic situation, spend a lot of money to replace the new CNC type. The deep neck press is not very likely, and it is a big waste for the original ordinary deep neck press. The NC reform of the ordinary press is economical and fast, which is in line with China's national conditions and is improved. Deep neck press number) Steps) Analyze the current sampling point of the zero sequence voltage according to the formula and calculate the amplitude of the zero sequence voltage!.) Judgment! Is it satisfied!> 2x15V, as a premise criterion for whether or not there is a ground fault. If this condition is not met, proceed to step 1). If this condition is met, the zero-sequence current sampling analysis of each outgoing line is started. The zero-sequence active power of the line is the outgoing line number.)) If the zero-sequence active power of each line is compared, the largest one is the single-phase ground line.

4 Conclusion By analyzing the characteristics of the zero-sequence current in the single-phase grounding of the compensation system, the principle of selecting the line based on the active component of the zero-sequence current is proposed. The essence is to find the algebraic value of the maximum zero-sequence active power sudden change. The advantages of the recursive DFT algorithm and the algorithm steps for implementing the line selection principle are also analyzed. This algorithm only uses the real and imaginary parts of the signal, avoiding any calculation of the phase relationship. The calculation amount is small, the calculation speed is fast, and the real-time performance is good. Therefore, it is a more effective method for compensating the system to determine the single-phase ground fault.

Hu Tianlu. Leakage protection of mine power grid Beijing Media Carbon Industry Press, Tang Wei. Selective leakage protection. Beijing: Coal Industry Press, 1995 Fan Wei (1968-), male, engineer. He is currently a graduate student at the China University of Mining and Technology.

; Editor-in-Chief: Hu Changchi) Effective Ways to Control Rate. In view of this, the A11-20A deep-neck press produced by Jiangsu Yangzhou Xingli Machinery Manufacturing Co., Ltd. was economically modified.

2 Numerical control transformation of deep neck press refers to the deep neck presses: OP numerical control unit operation panel, MCP machine panel, ENC numerical control unit, DI/0 input and output module, X-axis and Y-axis stepping motor and Driver, X-axis and Y-axis three-phase hybrid stepping motor, press main motor is three-phase 380V), electromagnet clutch YA (model is MQ1-5131, 380V/50HZ) and some X, Y-axis positive and negative limits It consists of a position switch, an emergency stop switch and a safety photoelectric switch.

圄2 deep neck press CNC system structure 圄 1-0P operation panel 2-MCP press machine panel; 3-ENC numerical control unit; 4-DI/0 input and output module; 5--machine electric control box; 6-master Motor; 7-YA electromagnetic clutch; 8- emergency stop switch, limit switch, photoelectric safety device; 9-X axis and Y-axis stepper motor driver; 10-X-axis and Y-axis stepper motor working principle is based on processing needs The machining program is programmed, input to the numerical control unit ENC through the operation panel, or programmed on the computer and simulated without error. The intelligent communication interface is connected to the numerical control unit ENC to deliver the command or data to the numerical control unit. According to the requirements of the program, the numerical control system divides and controls the main motor M and the electromagnetic clutch YA through information processing and distribution, and controls the X-axis and Y-axis to move a few minimum displacements to realize the relative movement of the press block and the workpiece. Processing of products. The main motor control principle is shown in the figure. The control of the main motor is divided into manual control and automatic control. Manual control Manual control is generally used for inspection and debugging or processing of single components. Close the knife switch "G. At this time, the transfer switch is placed in the manual position, the key switch SA1 is closed, the start button SB2 is pressed, and the KM1 is sucked and self-protected. The main motor M starts to rotate, presses the manual button SB3 or the foot switch SF, the intermediate relay KA pulls in, the electromagnetic clutch YA turns on the AC380V power supply, the pressure block slides down, and the part processing starts, and the SB1 is a stop button.

During normal machining, the changeover switch SW1 is placed in the automatic state. When the machining starts, the numerical control unit ENC issues a command, 1 is engaged, the contactor KM1 is powered on, the main contact is closed, and the main motor starts to rotate. When the stamping is required, the king 3 issues a command, the intermediate relay 3 pulls in, and the KA pulls in, the electromagnetic clutch YA turns on the power, the clamp operates, and the machining of the parts is started. The NC issues an instruction when it needs to stop. 0, 2 pull-in, disconnect KM1 and KA, the main motor M and the electromagnetic clutch YA are powered off at the same time. The 0, 1, 2, and 3 intermediate relays are controlled by numerical control programming. They are all connected with a freewheeling diode to prevent the reverse high voltage of the relay from being powered off and the ENC numerical control unit.

(3) Hybrid stepping motor feed system) The transformation of the feed drive part of the deep neck press is to remove the mechanical transmission mechanism of the original machine tool. The stepping motor is used to reduce the driving screw through the gear mechanism to drive the longitudinal and lateral movement of the workpiece. As shown, the longitudinal feed is the X-axis drive, and the stepping motor 3 is fixed on the chassis, and the gearbox 2 drives the lead screw to move the workpiece longitudinally. The Y-axis drive, that is, the lateral feed, is driven directly by the stepping motor 1 to drive the lateral movement of the workpiece. Longitudinal feed uses a speed reduction mechanism to achieve the required pulse equivalent, as well as structural requirements and increased torque.

圄4 feed system structure 圄1-Y axis stepper motor gearbox; 3-X axis stepper motor; 4-bed; 5-workbench) Three-phase hybrid stepping produced by German BERGERLAHR The motor and its driver apply the AC servo principle to the stepper motor system. The stepping motor draws the advantages of the two-phase and five-phase motors, and the matching driver adopts the working mode of the AC servo motor driver. This motor system completely solves the low-speed crawling, resonance zone, sound and high speed of the traditional stepping motor. It has shortcomings such as low torque, so it is called a stepping motor system with AC servo motor operating characteristics.

Referring to the stepper motor drive control schematic diagram, the AC380V power supply is isolated and stepped down by the transformer TB into AC220V. The power supply voltage of the stepper motor driver is connected to the L and N terminals, and the numerical control 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 stepping motor. The drive and stepper motor PE terminals require reliable grounding.

圄6 stepping motor winding wiring and current waveform 圄 reference and shown, Baigra company applies AC servo motor driver principle to stepper motor driver, input AC220V is rectified to produce DC325V pulse width modulation to 325V step type The sinusoidal current waveform, each step corresponds to the motor rotating one step, the motor speed is changed by changing the frequency of the output current of the driver, and the number of steps of the output does go away from the angle at which the motor rotates. The current flowing through each phase winding is a stepped sinusoidal current. Because of the sinusoidal step current drive, the current change of the motor per step is small, so there is no bad phenomenon such as low speed crawling, resonance, and loud sound. The operating characteristics are almost the same as those of an AC servo motor. Only three power lines are used between the motor and the driver, and as with the AC asynchronous motor, there is less possibility of wiring errors. The driver board is protected against three overheating, overvoltage, undervoltage, motor phase-to-phase and overcurrent protection. The driver has a semi-flow function. When the stepper motor is subscribed to the 2002 Coal Mine Electromechanical Magazine bookmark1, the magazine will issue it by itself. Address: No. 1 Tianyaoqiao Road, Shanghai, 200030, telephone (021 after the static 100 is charged, the output current of the drive is automatically reduced to 60 of the output current to prevent the motor from heating.

In short, in the practical application of the three-phase hybrid stepping motor drive system, it has fully demonstrated a series of advantages such as high positioning accuracy, fast response speed, large torque, small motor heating, and no resonance zone.

(4) Protection devices such as emergency stop limit 圄 (safe stop device such as emergency stop limit ENC-NC unit; SB6-emergency stop button; SB5-start button; SB4-overtravel release button; S01, S02, S03, S04 -X-axis Y-axis positive and negative limit switch; ZCZ-clamp work detection switch 1) CNC system with soft and hard limit protection. The soft limit alarm is created by setting the maximum and minimum coordinate values ​​of the axes of the machine in the machine coordinate system. The area is called the working area and the limit is set inside the hard limit. The stroke limit of the hard limit protection is made up of the stroke switch. Once the stroke switch is pressed, the feed drive power is cut off immediately, and the CNC system is notified to generate an overtravel alarm. If an abnormal situation occurs during the machining process, pressing the emergency stop button SB6 will immediately cut off all the driving power to achieve emergency stop. After the fault is removed, the emergency stop must be manually removed to continue working. ZCXZCY is the working point of the deep neck press. ZCZ is the clamp detection device. It is programmed with the electromagnetic clutch YA to use the processing of complex graphics.

3 Conclusion After the numerically modified deep neck press, the main advantages are: the system is flexible and reliable. With input information storage capability, the common machining program can be input into the memory at one time and called at any time. The numerical control unit uses the computer as the control component with less hardware, which reduces the failure rate of the components of the system, thereby improving the reliability.

System software control, easy to expand, and adaptable. Complex patterns can be processed by changing the program to machine different parts.

With self-diagnosis ability, easy maintenance. The system has a diagnostic program that makes it easy to detect fault types and locations with less downtime.

The program is easy to edit. The program can be added, deleted and modified in the field. It can also be programmed and simulated on the computer and transmitted to the CNC unit by communication.

Fully automated processing is possible. In the process of processing, only the processing plate is clamped, and the start button is pressed on the machine tool, and the remaining processing process can realize fully automated processing, which greatly reduces the labor intensity of the operators and is welcomed by the field workers.

Can achieve security protection. If someone accidentally enters the processing area during the machining process, the CNC system can automatically cut off the power supply to achieve safety protection and ensure the safety of production.

Save money. Save a lot of money compared to the purchase of a new CNC deep neck press.

The control principle is more complicated, requiring maintenance personnel to have a wide range of knowledge and strong hands-on ability.

Highly familiar and trained programming and operators are required.

The Department of Electrical Engineering of the School of Engineering is currently a visiting scholar at the Institute of Robotics, Shanghai Jiaotong University, and has published more than 20 papers.

; Editor: Yao Ke)

(Finish)

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