Design and application of the hottest AC server in

Abstract: This paper mainly introduces the design and successful application of Delta PLC and AC servo driver (ESDA) in CNC four head drilling machine, and the application of villen touch screen in the control system of full servo CNC four head drilling machine. The configuration, input/output wiring diagram and ladder diagram of drilling machine PLC system are described in detail

key words: Delta eh32-dvp PLC; Villen touch screen; AC servo driver (ESDA); CNC four head drilling machine control system; Ladder diagram

1 introduction

the traditional drilling process of brake pads includes releasing, moving positioning, drilling, re moving positioning, re drilling and other operations, and finally taking out the pads

after decades of development, the drilling technology of brake pads in China has been continuously improved and innovated. Especially in recent years, the injection of scientific research strength from universities and scientific research institutions, as well as the combination of production, study and research, have made the drilling technology of brake pads in China develop rapidly and gradually become automated

traditional drilling machines are mostly manual drilling machines. Because they are manual spindle transmission structure, there is no electrical transmission, resulting in the following shortcomings: slow drilling speed, low efficiency, and large labor volume of workers; Due to the diversity of drilling arrangement, under the condition of fast, accurate and reliable, the traditional manual drilling machine can not meet the higher and higher requirements,

at present, the full servo CNC drilling machine 3 The parts of pendulum shall not be disassembled or replaced casually, which has been gradually applied in brake pad enterprises. Now the full servo drilling machine has good advantages in output, efficiency, labor intensity and product quality, so it will become the mainstream of brake pad drilling in the future. Among the many newly developed products, the four head CNC drilling machine has high precision, large batch, and the function of automatic film feeding and automatic film unloading. It can process two pieces at the same time, and can drill continuously, which greatly reduces the labor intensity. Among the similar products, the best ones will be favored in the brake pad industry in the future. They have broad development prospects and will occupy a stable place in the market

2 four head CNC drilling machine system

2.1 system composition: the control part adopts PLC, and is equipped with a human-machine interface to modify program parameters, set and monitor the operation status, and the contents of the human-machine interface can be programmed. The circular rotary table is a full digital AC servo system. The servo motor drives the reducer, and the reducer drives the rotary table to rotate it at a certain angle by moving the rotary table, and then the drill bit starts to drill the set hole. The servo motor has accurate positioning and fast speed. Set the servo according to the drill bit, brake pad and feed rate. 1. Regularly check whether the connecting line on the rear panel of the controller can contact the superior and reasonable speed, and set its start and stop during operation. The turntable is equipped with an origin limiter, the servo driver has abnormal detection, and the alarm information can be displayed in the man-machine interface. In order to facilitate debugging and maintenance, all operations are set with manual functions, such as forward and reverse rotation of manual servo motor, start and stop of drill motor, forward and backward of drill, etc. In the production process, new films are continuously added, and automatic continuous production can also be achieved

2.2 PLC control wiring diagram

according to the functional requirements of the control system, the hardware wiring diagram of the PLC control part of the four head NC servo drilling machine control system is designed, as shown in the figure. The manual control part on this control panel is mainly used when debugging the system, and it is basically idle after debugging

figure hardware wiring diagram of PLC control part of NC four head servo drilling machine system

2.3 overall process design

according to the functional requirements of the control system, the control process of drilling brake pads is divided into manual control mode and automatic control mode. In the manual control mode, each device can operate independently through panel and touch screen operation, there is no sequence and mutual interference between them, and the mode process is shown in the figure

diagram mode selection flowchart

1 Manual control mode

in the manual control mode, the operation of each device can be controlled independently. The flow chart of the manual control mode is shown in the figure

figure flow chart of manual control mode

in this mode, the forward and reverse operation of the rotary table can be controlled through the buttons on the touch screen (reverse rotation is prohibited when there is film), and the drill bit and film feeding cylinder can move forward and backward at will. Through the separate operation of the solenoid valve, the performance of the drill bit and the universal experimental machine cylinder of Jinan experimental machine factory can be tested

2. When the automatic control mode

is in the automatic state, press the automatic on button, and the system starts to run automatically. Its working process includes the following aspects

1. Turn the manual/automatic knob to the automatic position, the turntable returns to the original point first, and then press the automatic on button

2. The turntable starts to rotate by a set angle and stops after reaching the film feeding position

3. The film feeding cylinder starts to feed the film. After reaching a certain pressure, it changes from forward to backward. The film feeding counts and stops after retreating for a certain time. When the sheet feeding is counted, skip to step 5.

4. Stop after the turntable rotates 60 degrees (a week is divided into 6 equal points), and then skip to step 3.

5. Stop after the turntable continues to rotate a set angle

6. The head starts to drill ahead, and after drilling is completed,

7. After a period of time, check whether a piece is drilled, and skip to step 5 before drilling is completed; After drilling, turn the rotary table to a certain angle, and check whether the automatic stop button is pressed. If not, skip to step 3 and, and press it to stop

the workflow of automatic control mode is shown in the figure

3. Ladder diagram design of each module

3.1 manual program

after the system is powered on, place the manual/automatic knob in the manual state, and the operation of each device can be controlled through the buttons on the touch screen on the panel. The manual design on the touch screen is shown in the figure. The manual control system is mainly to facilitate the debugging during the initial assembly of production and when changing different types of brake pads to detect whether each equipment can operate normally. The manual control ladder program is shown in the figure

figure manual operation screen

figure manual control ladder program

the setting of manual mode is mainly to facilitate system debugging and maintenance. During debugging, different devices can be debugged, and finally the whole system can be debugged together. When errors occur, it can also quickly find out which device is the problem; If there is a problem in the operation of the four head servo NC drilling machine system, it can also be checked manually to facilitate maintenance. The figure only lists some manual procedures, and other operations are similar. In the drilling process of four head servo NC drilling machine, automatic control is mainly used. The following describes the automatic control process

3.2 automatic program

in production, most of the four head servo NC drilling machine systems are in automatic operation. The system detects various states through PLC, controls the operation of the equipment, and automatically operates after starting according to the set parameter sequence. The parameter setting is shown in the figure, and the ladder diagram of the automatic control part is shown in the figure

parameter setting screen (1)

parameter setting screen (2)

diagram ladder diagram of automatic control part

in the ladder diagram of automatic control part, it can be seen that the automatic mode adopts step-by-step program, which is simple and clear. Part of the ladder diagram focuses on the control of the number of pieces sent at a time and the servo positioning. Set the speed and rotation angle in advance, and then execute the PLSR or Plsy command. After the pulse is sent, the servo will stop. Other readers can write it by themselves according to their needs

3.3 servo positioning program

when starting the servo motor, you need to set the frequency and the number of pulses to go first, and control the positioning of the servo motor through the servo driver. PLC sends pulses and directions to the servo driver through P around the needs and expectations of enterprises and the public, and then the servo driver makes the servo motor run or stop. The program required for servo is shown in the figure

diagram servo program ladder diagram

3.4 part of the main program

the main program is mainly used for the initialization of various data, including most of the servo positioning program, which is used for the common part of manual and automatic programs, and is inseparable from manual and automatic programs. Its ladder diagram is shown in the figure

diagram main program ladder diagram

4 problems and solutions in system design

in the four head NC drilling machine system, the main problems encountered focus on equipment selection, placement position, debugging and production process control

4.1 hardware problems

in this system, the selection and placement of various equipment, the position selection of proximity switches, the setting of PLC peripheral circuits and wiring, the selection of sheet feeding position, and the position of drilling motor are the main hardware problems of this control system

in terms of mechanical design, oil cylinders need to be used in the control process, so there are certain requirements for hydraulic oil, which requires a certain pressure and a very high degree of cleanliness. In summer, due to frequent drilling, the temperature of hydraulic oil will rise for a long time, which will affect the speed of oil cylinder. It can be improved by increasing circulating water or adding cooling fan. During the drilling process, there is a lot of powder flying out of the brake pad drilling, which can be improved by adding protection and vacuum cleaner. The rotary table is driven by the reducer, which cannot avoid the existence of the frame. Therefore, in the automatic process, it can only rotate forward. This greatly reduces the error and improves the accuracy

in terms of the peripheral hardware connection of PLC, because there is a very slight electrification on the surface of the servo driver, the shell of the servo driver must be grounded. During operation, workers should put and take pieces back and forth, and the panel should be made into a rotatable one. At ordinary times, turn to the best position, which is convenient for workers to operate

4.2 software problems

the main problems in software are logical errors and clerical errors. After the program is written, the PLC program needs to be annotated and checked on the computer first, and the touch screen program can be checked by simulation software, and then improved in debugging

5 design summary

the above describes in detail the design process of the four head CNC drilling machine system. The control system uses delta eh series PLC as the control host, and controls the motor, servo motor, relay, contactor, oil cylinder and other related mechanical structures through the villen touch screen, buttons, knobs, limit switches, servo drivers, etc., realizing the functional control of various equipment, It meets the control requirements of the system. (end)