PLC control and design of automatic feeder of the

2022-08-14
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PLC control and design of punch automatic feeder

Abstract: This paper introduces the design and PLC control of punch automatic feeder, and analyzes the working principle of mechanism and PLC programming method

key words: punch; Automatic feeding; PLC control

first, the technical status of the automatic feeding machine of the press

the automatic feeding machine of the press introduced in this paper is a feeding machine for cold extrusion ferrule parts, and it is an ideal attachment for the technical transformation of the press. The feeder overcomes the shortcomings of punch feeder at home and abroad. For example, the rf20sd-0r11 manipulator feeding device in Japan is integrated with the punch, which feeds from the horizontal (side), has complex structure, difficult assembly, manufacturing and maintenance, and is expensive, and is not suitable for the longitudinal feeding requirements of our punch. R the composite polyurethane adhesive industry in China has achieved continuous, rapid and stable development. The structure of f20sd-0r11 is composed of the crankshaft output shaft on the punch, which expands and contracts through the spline shaft, and the ball joint parts are connected with the gears of the manipulator. A series of transmission parts such as bevel gear, cylindrical gear, rack, cam, shift fork, screw rod and so on make the gripper of the manipulator perform the same actions as the beat of the punch to complete the feeding, Another set of independently driven movable conveyor is set to transport the workpiece to the predetermined position through the material separation mechanism. The configuration of such a mechanism is limited to Japanese equipment and cannot be applied to domestic punches. In some domestic feeding mechanisms, the working table of the punch press drives the slider to slide horizontally on the slide through the connecting rod spring, pushes the materials from the chute to the center of the die through the material separating mechanism, and drives the flushed materials away through the linkage striking plate. The whole set of reciprocating mechanisms is relatively simple, without the conveying mechanism, reliable linkage, and easy to manufacture. However, the manipulator cannot lift and clamp the material, and the material chute is tilted and slides down by the weight of the material. If the specification weight changes, the sliding speed of the workpiece on the material chute is inconsistent, which is easy to produce stacking. The pushing mechanism does not see from the definition that the material is clamped, the positioning is incorrect, the scrap rate is high, and it is unsafe to use

combined with the working characteristics of domestic punch press, using the cooperation of manipulator and conveying mechanism as the main device, and then using automatic unloading safety protection, an automatic feeder with great application value and promotion significance is designed

II. Structural design

the feeder is mainly equipped with 3150kN punches, and can also be equipped with 1600kn or 1250kn punches. It is mainly composed of frame (including supporting feet, electrical box, angle iron frame), conveyor (including motor, gearbox, roller, conveyor belt, material table, material channel, material separation mechanism, material retaining mechanism, etc.), manipulator (including lifting cylinder, clamping cylinder, sliding plate, support, connecting rod hinge, etc.), oil supply device (including oil tank, hydraulic pump, etc.), unloading mechanism, safety protection device, etc. (as shown in Figure 1)

Figure 1 structural diagram of automatic feeder of punch

1 Rack 2 Conveyor belt 3 Manipulator 4 Spacer plate 5 Punch table

6 Silo 7 Baffle plate 8 Workpiece 9 Motor 10 The die

frame is mainly connected with the punch, the manipulator is installed and slides on a certain track, and the conveying mechanism and electrical components are installed

the conveyor is driven by a motor and transmitted to the driving shaft through the belt and reducer, so that the conveyor belt can work at a certain linear speed. The work enters the material path (manually) through the material table, and then is transported to the predetermined position through the material separation mechanism

III. PLC control

the manipulator needs to complete the action of moving the workpiece from a to B. The schematic diagram of the manipulator is shown in Figure 2. Its action process is shown in Figure 3

Figure 2 Schematic diagram of the manipulator "mark sarvary, President of anjianneng, said that figure 3 the action process of the manipulator

each working arm of the manipulator has upper and lower limit switches and left and right limit switches, while its clamping device does not have limit switches. Once the clamping starts, the timer in the control PLC starts, timing constraints, and the clamping action is completed immediately. After the manipulator reaches point B, the time of loosening the workpiece is also controlled by the timer. When the timing ends, it means that the workpiece has been loosened. The distribution of input and output points in PLC is shown in Figure 4

Figure 4 i/o point distribution diagram in PLC

the action process of the manipulator is as follows: when the start button is pressed, the manipulator starts to descend from the origin. When it descends to the bottom, it touches the lower limit switch (X401 is connected), and the descent stops. At the same time, turn on the timer, the manipulator starts to clamp the workpiece, the timing ends, and the clamping is completed. When the manipulator rises to the top, it touches the upper limit switch (X402 is on), and the rise stops. The manipulator moves to the right. When the right movement touches the right limit switch (x403 is on), the right movement stops. The manipulator descends to the bottom. When it touches the lower limit switch (X401 is on), the descent stops. At the same time, turn on the timer, the manipulator relaxes the workpiece, the timing ends, and the workpiece has been loosened. When the manipulator rises to the top and touches the upper limit switch (X402 is on), the rise stops. When the manipulator moves left to the origin and touches the left limit switch (X404 is on), the left movement stops. Then a cycle of manipulator action ends

the automatic operation flow chart of the manipulator is shown in Figure 5. The state transition diagram is shown in Figure 6. The ladder diagram is shown in Figure 7

Figure 5 automatic operation flow chart

Figure 6 automatic operation state transition diagram

Figure 7 ladder diagram of automatic operation of manipulator

conclusion

the automatic feeder of punch is essentially a manipulator, which can automatically load and unload materials, improve production efficiency, ensure product quality, improve work labor intensity, and ensure personal safety. It has great application prospects in cold extrusion processing industry

PLC is used to control the mechanism, and microcomputer is used as the man-machine interface, which better meets the requirements of control and system. And the test is accurate, the operation is high-speed, reliable, and the service life is long. It is a real-time monitoring system, which has a certain reference value for the control and design of related systems

references

1, Zhou Yanxun Computer automatic measurement and control system Beijing: National Defense Industry Press, 1992

2, Zhang Xinhua Discussion on automatic monitoring system composed of PC-PLC Telemetry and remote control, 1998 (6)

3, Lu Zhikang, Zhang Xinhua Research on remote automatic monitoring system Microcomputer applications, 1999 (4)

4, Zhang Xinhua et al The principle and design of automatic feeding of punch press Forging technology, 1993 (11 years of development time 5) (end)

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