PRV is a hydraulic 3-roller variable geometry plate rolling machine, which is used to complete the pre-bending, rounding, and rounding of the end of the plate without turning around after loading carbon steel and low-alloy steel for various containers at room temperature. It can roll arc-shaped workpieces. The top roll moves vertically and the two lower rolls move horizontally.
- Pre-bending is achieved by moving the lower roll horizontally so that the upper roll is in an asymmetrical position relative to the lower roll.
- When rolling the workpiece, the two lower rollers are driven by the motor and the reducer. Since the elevation of the lower roller remains unchanged, it is convenient for feeding and operation.
The left and right main cylinders of the PRV variable geometry plate rolling machine are arranged one above the other. The two lower working rolls of the bending rolls are the main driving rolls, the top roll is pressed down by the hydraulic cylinder, and the lower roll is driven to rotate by the double motor through the deceleration box. The double motor drive can greatly reduce the load loss (useless work) so that the Large work (useful work) is used for coiling; the lifting of the top roll is driven by hydraulic pressure, the lifting displacement is controlled by a computer, automatic leveling, screen display, synchronization accuracy ± 0.2mm.
The horizontal movement of the lower roll adopts mechanical transmission, and the horizontal movement is decelerated by the worm gear reducer and is driven by the linear motion through the screw and the nut pair. The tipping and reset of the tipping frame adopt hydraulic transmission. When the main drive is rounded, two motors drive the two lower rollers through two reducers. It has the advantages of small size, compact structure, small footprint, high transmission efficiency, and environmental adaptability. Strong and other advantages.
PRV is a hydraulic 3-roller variable geometry plate rolling machine with an advanced and reliable structure, sufficient rigidity, reasonable material selection, precision manufacturing, excellent performance, long precision retention period, suitable for long-term continuous processing, stable and reliable operation, and simple operation.
Six structures and performance of PRV variable geometry plate rolling machine
The main structure of the variable geometry plate rolling machine(not a sheet metal rolling machine) is composed of a top roll device, two lower rolls and a horizontal moving device, an idler roller device, a main transmission device, a tipping unloads device, a frame body, a balancing device, etc.
Structure 1#: Top roll
The upper roller device is composed of a main oil cylinder, upper roller, double-row self-aligning bearing, and so on.
The two main oil cylinders provide the pressure required for rolling the plate, and the working pressure of the main oil cylinders is 19.5 MPa.
Double-row self-aligning bearings adopt low-speed, heavy-duty self-aligning roller bearings.
The upper roller is in the shape of a drum, and the load factor of the maximum pressure of the upper roller is 0.7 in the design, and the uniform load is preset to compensate for the deformation and deflection of the upper roller.
The material of the upper roll is 45# forged round, quenched, and tempered HB260~300 after rough machining, according to the JB/ZG4289-86 roll steel standard, the rigidity meets (1/700~1/1000)L.
Structure 2#: Lower roll
The lower roll device is composed of the lower roll, the lower roll bearing seat, the lower roll input gear, the lower roll sliding bearing, and so on.
The lower roll is made of 45# forged round, quenched, and tempered HB260~300 after rough machining, according to the JB/ZG4289-86 roll steel standard, and the rigidity meets (1/700~1/1000)L.
The sliding bearing of the lower roll is made of FZ-2 self-lubricating composite material.
The horizontal moving device is powered by a horizontal moving motor and drives the horizontal movement of the lower roller device through the worm gearbox, worm gear, and screw nut mechanism to realize asymmetric rolling of the plate. The main drive of the lower roll provides power, through the output gear of the main drive, the input gear of the lower roll, and the open transmission torque to the lower roll.
Structure 3#: Guide roll
The guide roll device is composed of a roller, a screw and nut mechanism, a wedge mechanism, etc.
The guide roll is made of 45 steel, quenched and tempered, with a hardness of HB190~220. The surface hardness of the roller is lower than that of the lower roller, and the surface is turned with spiral grooves, which effectively prevents the scale and impurities of the lower roller from damaging the working surface of the lower roll.
There are four guide rolls in one group, and the idler rollers move with the movement of the lower roll.
Structure 4#: Main drive
The main transmission device is composed of the main motor, V-belt, cylindrical gear reducer, electro-hydraulic push rod brake, etc.
The output gear drives the two lower roll gears.
The main drive can be reversed to provide rolling torque for plate rolling.
Structure 5#: Tipping unload
The tipping unload device is composed of a ram, an overturning oil cylinder, and the like.
The tipping unloads cylinder piston rod is chrome-plated.
The overturning of the tipping unload device facilitates the removal of the workpiece along the axial direction of the roll.
Tipping unload device
Structure 6#: Fixing, tipping unloading side frames, chassis
- The fixed and tipping unload side frame and the chassis are welded parts of steel plate, and the stress is removed after welding.
- Fixed, tipping unloads side frames are used to accommodate two master cylinders.
- The chassis adopts a frame structure with a high torsional section coefficient, fewer anchor bolts, and convenient installation and debugging.
The hydraulic system of the PRV variable geometry plate rolling machine
The hydraulic system consists of gear pumps, valve groups, fluid connectors, hydraulic accessories, etc. The hydraulic valve adopts the superimposed valve series, the pipeline layout is simple, and the maintenance and debugging are convenient. The system consists of three loops, overpressure protection and pressure regulation loop, synchronous loop, and speed loop. The pressure regulating circuit regulates the working pressure of the system through the main relief valve. The working pressure of the system is 19.5MPa.
The synchronous circuit synchronizes the rise and fall of the upper roller through the diversion throttle valve, and the throttle valve is adjusted up and down; the displacement sensor detects that the synchronization accuracy of the upper roller is ±0.15mm. The speed loop controls the overturning and reset of the machine on the overturning side, and the throttling speed of the loop is adjusted through the throttle valve.
Protect: The ascending and descending of the upper roller are respectively provided with relief valves for pressure limit protection.
The electrical system of the PRV variable geometry plate rolling machine
The variable geometry plate rolling machine‘s electric control system is composed of electric control cabinet and operation console. Power supply 380V/50Hz (customized upon request).
The control circuit adopts PLC programmable controller system, fewer relays, reliable action, and long life.
The control cabinet is equipped with all control buttons, indicator lights, and a programmable touch display to complete the product rolling plate process.
To monitor and control the rolling working status of the whole machine.
- Each motor has a corresponding circuit breaker for over-current short-circuit protection;
- Each motor has a corresponding thermal relay for overload protection;
- The horizontal movement of the lower roller has a corresponding limit switch for limit protection;
- The tipping unload and reset of the tipping unload cylinder are respectively equipped with upper and lower limit switch limit protection;
- The main power circuit breaker has a shunt release, and there are “emergency stop” buttons on the side of the console and the overturning support to cut off the main power remotely.
After the tipping unload rack is fully reset, the upper roller can be lifted and lowered, moved back and forth, and the lower roller is reversed and other actions can be carried out (use the “tipping unload rack reset” limit switch for detection);
When the upper roll is at the upper position, the lower roll moves horizontally and the overturned side falls independently (the “upper roll upper position” limit switch is used for detection);
When the working pressure of the upper roll pressure switch is greater than 1/3P, the lower roll cannot move back and forth (the pressure switch is used for detection).
When the lower roller motor and horizontal moving motor are overloaded, the fault indicator will prompt;
When the PLC fails, the fault indicator will prompt.
PLC control system of the PRV variable geometry plate rolling machine
This industrial computer control system is a special scheme control system specially designed and manufactured for the CNC hydraulic level down adjustment three-roll plate bending machine. This system includes hardware parts such as the main electric cabinet, industrial computer cabinet, and special control configuration software for the industrial counting machine.
It is equipped with a fixed operation table and a wireless remote control button box, which is convenient for the operator to use.
Composition and principle
The core of the micro-control system of PRV three-roll plate rolling machine: industrial control computer, S7-200 programmable logic controller (PLC) produced by SIEMENS, display (resolution up to 1024×768), German “SIEMENS” PLC and Siemens double breakpoint Composed of DC relays and their peripheral drive control circuits, sensors, etc. The programmable logic controller (PLC) is respectively connected to the displacement sensor of the oil cylinder and the signal output terminal of the imported original pressure sensor to obtain its displacement and pressure status. The computer-specific control program obtains displacement, pressure, and other data and PLC input and output status through the PLC. The computer and PLC integrate the above information, control the output of the PLC through intelligent processing, and control the operation of peripheral electrical appliances and hydraulic equipment through the intermediate relay. superior. The system is advanced in design, flexible in operation, safe and reliable in operation, good in fault tolerance, and can operate reliably even without a computer.
Micro control system
The control system has two control methods, manual and automatic, and it can still operate reliably without the computer and can be switched easily. The main interface of the system is divided into five parts: title bar, menu bar, toolbar, user interface, and status bar. Among them, the user interface consists of the operating parameters and status area (displaying the pressure, displacement, and ideal shape of the workpiece of each cylinder), the input/output status area (displaying the main input/output working conditions of the programmable controller),
The processing parameter area (displays the current processing parameters and other data) and the alarm prompt area (displays the alarm and prompt information); the current system protection pressure and system time are displayed on the status bar.
Control system function
The control system has the following functions:
The display mode of the microcomputer system is very rich and perfect: the lifting displacement, inclination, pressure of the main cylinder, the horizontal displacement of the lower roller, and the pressure of the balance cylinder are all displayed on the screen.
The screen displays the working status of each hydraulic solenoid valve, which is green when the power is on and red when the power is off. The codes and arrangements of the solenoid valves are the same as those of the hydraulic station. detection.
Open the master cylinder speed detection window to detect the speed of the left and right master cylinders when lifting, so as to artificially adjust the roughly synchronous speed of the master cylinders when lifting.
Various alarms upper and lower limits, etc., are displayed in eye-catching red text in the list box of “Alarm and Status Information” in the upper middle part of the screen; the real-time protection pressure and system time determined by the system according to the input conditions will be
Displayed in real-time on the status bar at the bottom of the screen.
The microcomputer control system includes functions such as calculation, control, display, modification of system parameters, timing opening and closing of the lubricating pump, etc.
Input the relevant parameters of the workpiece from the keyboard, such as plate thickness, plate width, yield limit (the screen prompts the yield limit and strengthening coefficient of commonly used materials), and the diameter of the drum (the diameter of the cone and the diameter of the cone are respectively input), and the computer automatically calculates and optimizes the number of times of pressing. The amount of reduction each time, the horizontal movement of the lower roller, the theoretical forming radius of each reduction, and a load of each roller. Output the inclination of the upper roll when rolling the cone, output the minimum remaining straight edge value when pre-bending, and can arbitrarily select the pressing times and the length of the pre-bending straight edge under the prompt on the screen, and recalculate the new data. For overload or input errors in the process operations such as rolling plate, pre-bending, and cone rolling, the microcomputer reminds the operator to make corrections at any time. By clicking “Process Parameter Calculation”, the calculation of workpiece process parameters can be realized (as shown in the figure below). Fill in the processing parameters such as the physical properties of the workpiece material in the dialog box, click “Save and Exit” to save the parameter table in the database (it can be called directly in the future), and transfer the parameter table into the current workspace. Through the “Technical parameter selection” button, the previously saved workpiece processing parameter table can also be transferred into the current processing area (as shown below).
The calculated process parameters are automatically sent to the program control window. Users can also use the keyboard to manually input process parameters in the program control window or call the mature process parameters in stock to the program control window. The process parameters in the program control window are mainly the pressing times. , the amount of pressing each time, the amount of inclination, and the amount of horizontal movement of the lower roller, the operator can modify and set it arbitrarily.
After setting the process parameters, the operator can choose manual operation or automatic operation. During manual operation, the operator presses the working roll up and down and moving buttons, and observes the displacement value displayed on the screen to make the working roll reach the set value and start coiling; choose automatic During operation, move the cursor to the desired reduction value of the upper roll, press the Enter key, the upper roll will stop automatically when it reaches the set value, and the plate rolling can start, and the feeding of the plate is controlled manually. Keep the cursor still, slightly change the current pressing value of the cursor, and press the Enter key, the upper roller can move up and down or tilt slightly according to the current value, realizing digital operation. When the cylinder is rolled, the inclination is generally zero. Sometimes it is a common technological measure to make a small inclination of the upper roll belt to correct the misalignment of the steel plate.
Process parameter storage
The microcomputer can store a thousand process parameters of different workpieces, which are stored in the hard disk in a certain order, and the user can transfer them to the program control window for use at any time. Mature process parameters can be stored in the hard disk at any time.
In addition to various travel switches and protection components, the electrical control system has a microcomputer with soft protection function, which can alarm or control the limit stroke of each roller, the limit pressure of each cylinder, the oil level and temperature of the hydraulic station, and the blockage of the filter.
When rolling small workpieces with small diameters or pre-bending, according to the work roll load calculated by the calculation program, the operator can set the safety pressure of a single workpiece that is much lower than the maximum rated workpiece pressure of the machine, so that the machine can run in a safe state.
Modify system parameter
Click “System Parameter Settings” to modify the system parameters (to prevent accidents, modification is not allowed in the automatic state), as shown below.