Views: 3 Author: DURMAPRESS Publish Time: 2021-12-20 Origin: DURMAPRESS
In order to ensure the safety and reliability of the normal operation of the hydraulic bending machine, it is necessary to test the bending machine first. After the test process can be completed safely as expected, the formal work can be carried out again. After the test of the bending machine is completed, press the start button, the middle relay gets electricity, so that the solenoid valve gets electricity, and the slider slides rapidly under its own weight; When the slider is close to the workpiece, down to the limit switch, the solenoid valve is electric, the slider is slow down; When the slider contact with the workpiece, with the increase of the workpiece deformation, the workpiece resistance increases, so that the pressure of the upper chamber of the hydraulic cylinder increases; When the holding pressure of the electric contact pressure gauge is reached, the electric contact pressure gauge emits an electrical signal, which shuts down the solenoid valve.
The hydraulic pump is temporarily unloaded, and the time relay of the pressure holding time is connected for the pressure holding time. When the pressure limit of the electric contact pressure gauge is reached, the solenoid valve is connected for re-pressurization. This process is repeated, which is the pressure holding stage. After the pressure retention, the solenoid valve loses power, the pre-discharge time relay gets power, the hydraulic main oil circuit is connected with the oil tank, so that the hydraulic system can achieve pre-discharge; After the completion of pre-unloading, solenoid valve, electricity, slide block fast return; When the slider return to the top limit, the solenoid valve power, limit switch pressure, so that the solenoid valve, electricity, into the second working cycle.
The main control circuit of hydraulic bending machine contains three motors, which are the main motor (oil pump motor), the rear stopper motor and the slider stroke motor. There are positive and negative points between the stopper motor and the slider stroke motor. The on-off of each motor is controlled by the corresponding electromagnetic contactor. Contactor is mainly used to control motors and other equipment, has the protection of the low pressure release function, is widely used in mechanical and electrical drive system of electric appliance, one of its working principle is: when energized coil, coil current magnetic flux in core to overcome armature reset spring force of the electromagnetic suction, so that the armature contact action.
There are three kinds of classic action modes of hydraulic bending machine: point action, single action and continuous action. The three working modes of the composite circuit is particularly complex, and in fact, there is a certain similarity, in the actual production process is particularly widely used, and its working process is strong logic, has a certain representation in the machining equipment
CNC plate shearing machine with ARM processor as the core module, including input and output module, communication module, servo motor control module, power module, and hardware watchdog. The system uses photoelectric isolation, in order to prevent interference signals, at the same time through the input signal scanning and output signal control, shear machine shear process of a series of actions and the positioning of the rear baffle plate, and with the position lamp and alarm lamp display system of various information and working status.
Design of each module of CNC plate shearing machine:
(1) Input and output module. With the rapid development of electronic goods in China, the integration degree of each module is getting higher and higher. The selection of integrated components is conducive to improving the integration of the overall design and facilitating the later iteration and upgrade of individual modules. Therefore, this scheme takes these factors into full consideration in the selection of input and output modules, and chooses the integrated input and output module, which has both input and output circuits and input and output latched circuits, greatly improving the efficiency of human-computer interaction.
(2) Display module. Considering that industrial production does not need high resolution display screen, so this design in the selection of screen, on the one hand, the screen can provide a better display effect; On the other hand, the hardware cost is greatly reduced. The display screen also has the touch function, through the touch function can realize visual programming, control, the control program using the screen image display, strengthen the human-computer interaction, only to a certain extent, increase the man-computer interaction field of early development workload, but improve the efficiency and convenience of the product. At the same time, the running status of the system can also be visually displayed on the screen in real time.
(3) Servo motor control module. The operation of servo motor provides power guarantee for the whole system, and its accuracy is directly related to the shearing quality of plate shears. The accurate control of servo motor operation can be realized by using ARM to generate PWM control waveform signal. The resolution of PWM control waveform generated by the SELECTED ARM chip can reach 10bit, and the use of high-precision PWM waveform can make the servo motor run more precise and accurate. USES a three-ring cascade servo position control system, the system can send feedback waveforms to control system, the ARM control system with the module feedback waveform comparison, using the difference of the servo motor control waveform correction, further enhance the accuracy of the servo motor control and shear localization accuracy. The whole system ensures the accuracy of shear size and improves the reliability of the whole system operation.