First, the servo press technology
With the successful research and development of high-power servo motor and the rapid popularization and application of frequency conversion technology, a servo press with adjustable slider motion curve has appeared, which greatly improves the working performance and technical practicability of the press and makes the pressure develop in the direction of flexibility and intelligence.
After years of development, servo technology has been widely used in stamping field. In the field of product forming press and auto parts press, servo technology has blossomed after the efforts of many technicians. In the metal stamping industry, automobile parts, motor bearings and refractory products have been recognized and accepted by more and more manufacturers.
Second, the servo press technology
Pressure assembly is a common process method in mechanical engineering. Especially in the automobile and auto parts industry, the assembly of bearings, bushings and other parts is realized by pressure assembly.
As a new technology, servo press has advantages that traditional hydraulic press does not have. It is gradually replacing the traditional hydraulic press in the automobile manufacturing process, such as the press-fitting of the valve seat ring and guide tube of the cylinder head, the press-fitting of the water channel of the cylinder block, the press-fitting of the transmission bearing and the press-fitting of the hub bearing. , effectively improving the level of automobile manufacturing technology.
As far as bearing press-fitting is concerned, bearing is a moving part, and the effect of press-fitting directly affects the performance and life of vehicles or products and equipment. The higher the tolerance requirement of bearing for boring workpiece, the more important it is to effectively monitor the press-fitting force and displacement in the process of bearing press-fitting. The traditional press-fitting equipment powered by hydraulic pressure or pneumatic pressure cannot effectively control the pressure and displacement of press-fitting in the process of press-fitting, and the bearing will be stuck or unable to rotate due to the instantaneous overload of press-fitting force. The power source of the servo press is controlled by an intelligent, flexible and sensitive servo motor. Combined with the pressure sensor, the pressure, displacement and speed can be accurately adjusted, which can well solve the press-fitting overload caused by speed and pressure. At the same time, through the on-line monitoring of press-fitting force and displacement, the press-fitting effect can be effectively judged, the press-fitting parameters can be saved, and the traceability of press-fitting parts by the main engine factory can be realized. The process with similar precision requirements is suitable to be completed by servo press in the press-fitting process.
Third, the embodiment of the advantages after using the servo press
The traditional crank press has a fixed slider motion curve, poor process adaptability, high noise and high energy consumption. Compared with traditional crank press, modern servo press adopts AC servo motor instead of ordinary AC motor, and cancels flywheel and clutch on traditional crank press. Modern servo press can set the motion curve of the slider at will through computer and intelligent control technology, which has strong technological adaptability, low noise and low energy consumption, and can greatly improve production efficiency. Servo press represents the development direction of press, and it is of great economic and social significance to study servo press directly driven by servo motor.
1. The stroke length for improving productivity can be set as the minimum value of zui required for production, and the molding speed suitable for the processing content can be maintained;
2. The product has high precision. Through closed-loop feedback control, the accuracy of the bottom dead center is always guaranteed, the burr of the product is suppressed, and the generation of defective products is prevented;
3. Low noise, low noise mode (that is, the contact speed between the slider and the plate is reduced) reduces the service life of the die. Compared with the general mechanical press, the noise is greatly reduced, the vibration of the die is small and the service life is long;
4. Controllability of slider motion Users can make use of this feature to formulate a slider motion mode suitable for processing technology, which can effectively improve the accuracy and stability of products, improve the service life and productivity of molds, realize silent blanking, and even expand the processing range (such as magnesium alloy stamping, etc.). ). Suitable for punching, drawing, stamping, bending and other processes, as well as the characteristic curves of different materials. For example, the slider operation can be stopped to maintain the pressure, and the purpose is to improve the forming quality of parts.
5. Energy-saving and environmental protection: the flywheel, clutch and other energy-consuming parts of the traditional mechanical press are cancelled, which reduces the driving space, simplifies the mechanical transmission structure, has automatic lubrication and controllable stroke, and greatly reduces the running cost due to low power consumption.
Compared with the traditional press, the servo press not only has the advantages of stable operation, adjustable stroke and pressure, but also has the advantages of simple structure and high productivity of the traditional mechanical press. Its unique characteristics and advantages are: improving the automation and intelligence level of the equipment, realizing digital control, realizing the pressure forming process that ordinary mechanical presses can't achieve, improving the working characteristics of the press, saving energy and protecting the environment, prolonging the life of the die, simplifying the mechanical transmission mechanism, and having high safety, high reliability and good maintainability.
Fourth, press mode setting of servo press
1; Constant press-fitting speed and accurate stop position.
2; Constant press-fitting speed and accurate pressure stop.
3; Constant press-fitting speed and accurate displacement stop.
4; Constant press-fitting speed, I/O trigger stops.
5; Pressure/displacement, two-stage mode.
6; Pressure/pressure, two-stage mode.
7; Pressure/position, two-stage mode.
Five, servo press press assembly process
Single stroke six speed:
Fast forward: approaching the workpiece quickly.
Detection: vehicle detection from no-load to load.
Press-fitting: the workpiece is pressed in.
Buffer: slow down before the end of press-fitting.
Holding pressure: stop at the end of press-fitting.
Return: Quickly return to the working origin.
The whole press-fitting process is divided into six stages: fast forward, detection, press-fitting, buffering, pressure maintaining and returning.
When the machine is turned on in the automatic state, the machine will automatically find the mechanical origin. After setting the parameters, press the start button with both hands, and the indenter will descend to the detection position at a fast-forward speed (that is, the indenter is in contact with the press-fitted sample), and then the detection process will start at a detection speed decrease (that is, whether the pressure corresponding to the set press-fitted area position is within the allowable range when it is in contact with the sample for a short time). The detection process ends at the set detection limit position. If the workpiece has not detected the detection limit position, the indenter will stop (this function can avoid the failure of workpiece press-mounting), and then press the return button to return to the mechanical origin; When the contact pressure reaches the set value in the detection process, the indenter automatically switches to the press-fitting speed to start press-fitting the workpiece, and when the press-fitting reaches a certain position, it continues to press-fit the workpiece at the buffer speed. After press-fitting to the specified position, the pressure will be maintained according to the pressure-holding time set by the user, and the pressure head will return to the set working origin at the set speed after the pressure-holding time.
During the six stages of operation, the control system automatically completes data collection, analysis, diagnosis and archiving, ensuring the reliability of press-fitting in each stage in real time.