Гидравлический штифт пресса, Движение главного гидроцилиндра

1) Hydraulic-pin-press Fast down

Hydraulic-pin-press machine, After electromagnet 1DT, is energized, valve 3 and valve 7 work in the left position, valve 19 is opened, and the main hydraulic cylinder 5 moves down quickly under the action of hydraulic pressure and gravity, and the upper cavity of the oil is insufficient by the filling cylinder 6 and valve 20. supplement.

2) Hydraulic pin press, Slow pressurization. When the slider of the master cylinder descends to contact the workpiece, the resistance increases sharply, and the pressure in the upper cavity of the main hydraulic cylinder 5 rises rapidly, causing the valve 20 to close. At this time, the upper cavity of the master cylinder is only supplied by the hydraulic pump alone. In this way, slow pressurization is realized, and the pressurization speed is determined by the flow rate of the hydraulic pump. At this time, the oil flow line is the same as that in the fast descending.

3) Hold pressure delay

Hydraulic pin press, If it is a constant pressure process, when the pressure in the upper chamber of the main hydraulic cylinder 5 rises to the set pressure of the pressure relay 8, the pressure relay 8 sends a signal to de-energize the solenoid 1DT; if it is a fixed-range process.

When the master cylinder slider slowly presses the workpiece to touch the travel switch XW2, the travel switch XW2 sends a signal to power off the electromagnet 1DT. Regardless of the process method, once the 1DT is powered off, valve 3 and valve 7 are in the neutral position, and the pump starts to unload. Under the action of the M-type neutral function of valve 7, the main hydraulic cylinder 5 starts to hold pressure, and the pressure hold time Controlled by time relay.

4) Pressure relief reversal

Hydraulic pin press, When the pressure holding time is up, the time relay sends out a signal to energize the solenoid 2DT, and the pilot directional valve 3 reverses first. Due to the special structure of the pre-pressure relief directional valve 9 (Figure 1 only shows its schematic diagram), When the valve 3 changes direction, the valve A in the valve 9 cannot be reversed in time, but the valve D inside the valve 9 is opened, so the oil pressure in the upper cavity of the main hydraulic cylinder 5 is slowly released through the valve D and the valve A inside the valve 9. When the pressure in the upper chamber of the main hydraulic cylinder 5 drops to the point that the valve core of valve A moves due to the unbalanced upper and lower forces, and the valve A works in the lower position, the pressure relief oil circuit is cut off, and the right chamber of valve 7 is connected to control oil, so that valve 7 Reversing works in the right position.

5) Quick return

Hydraulic pin press, When the valve 7 is switched to the right position, the oil output from the pump passes through the valve 19, so the valve 20 is opened, and at the same time enters the lower cavity of the main hydraulic cylinder 5, the main cylinder slider quickly retracts, and the oil returns through the valve 20 Flow back to the filling cylinder 6.

6) Stop in place

When the master cylinder slider quickly retracts to depress the stroke switch XW1, XW1 sends out a signal to de-energize the solenoid 2DT, valve 3, and valve 7 are in the neutral position, the pump is unloaded, and the master cylinder slider stops in place.

2　The movement of the ejector cylinder

1) Eject up

After the electromagnet 4DT is energized, the ejector cylinder reversing valve 2 works in the right position, and the ejector cylinder 1 drives the lower sliding block to eject upward.

2) Stay when the lower slide moves upwards to depress the travel switch XW3, XW3 sends out a signal to power off the electromagnet 4DT and unload the pump. At this time, the ejector cylinder 1 and the lower slide stop moving.

3) Back down

After the solenoid 3DT is energized, the valve 2 works in the left position and the ejector cylinder 1 drives the lower sliding block to retract downward.

4) Stop in place

When the lower sliding block moves down to depress the travel switch XW4, XW4 sends out a signal to de-energize the solenoid 3DT, valve 2 is in the neutral position, the pump is unloaded, and the ejector cylinder 1 and the lower sliding block stop in their original position.

3　 Development of PLC control system for Y32-2000 hydraulic press

Based on the above analysis of the working principle of the Y32-2000 four-column universal hydraulic press, it is planned to adopt PLC technology to develop its control system. This is not only because PLC technology has become quite mature after years of development, but its software and hardware reliability are both The reason is very high, and more importantly, because the mainstream technology of the domestic four-column universal hydraulic press control system is PLC technology. According to the above working process of the main hydraulic cylinder and ejector cylinder, it can be seen that the input part of the PLC includes: start button, stop button, pressure relay, downward pressing button, master cylinder forced return button, ejector button, ejector cylinder return button and position Control components (main hydraulic cylinder upper limit switch, fixed stroke compression limit switch, ejection cylinder upper limit switch, ejection cylinder lower limit switch); the output part includes: solenoid 1DT, 2DT, 3DT, 4DT of the electromagnetic directional valve , Motor control coil.

4. The control system of the Y32-2000 four-column

universal hydraulic press is developed using PLC technology. It has the advantages of simple development, good reliability, high control accuracy, and convenient maintenance and testing. Therefore, the working performance, processing efficiency and reliability of the hydraulic press are all Get effective improvement.

5. Current status and prospects of forging hydraulic press

As a kind of full hydraulic control equipment, forging hydraulic press mainly uses liquid pressure to transmit energy. Compared with traditional mechanical pressure gauges, its transmission speed and pressure do not need to be adjusted, and all power and pressure can be output no matter where it is. Perform structural actions to achieve expectations. Hydraulic components have high versatility standards and are very accurate in size and precision control, so they are often used in steel, machinery, non-ferrous metals and other industries.

6. Overview of forging hydraulic press

Hydraulic pin press, The forging hydraulic press is mainly composed of the following parts: 1) The main body, as an important actuator, is mainly used to press forgings; 2) The hydraulic system is mainly used to drive the main engine; 3) The electrical system, the key process is the control system, and the application range of the forging hydraulic press Relatively wide, it is commonly used in free forging processes such as drawing, coughing, bending, and shifting. It can reasonably control the reduction size, especially in the billeting of steel ingots with reasonable forging temperature. It is mainly used for steel, machinery, railway In different industries such as locomotives. Different technologies such as microelectronics, electronic control, and mechanical hydraulics are mainly used in the unit. In addition, the project covers a wide range and the system is huge.

8 Status and characteristics of forging hydraulic press

Hydraulic pin press, Domestic large hydraulic forging presses developed earlier and have been put into production since the 1980s. Then large free forging hydraulic presses were put into production one after another, and many super large hydraulic forging presses have gradually developed to their peaks. At the beginning of the 21st century, domestic large-scale free forging hydraulic presses developed rapidly. Since 2006, the first heavy-duty free forging hydraulic press lags behind, and in 2008 the second heavy-duty machine has appeared one after another. Then in 2009, the Shanghai Heavy Machinery Factory produced a free forging hydraulic press with a weight of 165MN.

Hydraulic pin press, In 2010, a free forging hydraulic press with a weight of 185MN was produced in China. At present, there are already 9 free forging hydraulic presses with a weight of 10,000 tons in China, the actual scale and forging force are close to the world’s first. In addition, there are some similar free forging presses under construction, with nearly 16 units, accounting for 50% of the global number. The total number of forging hydraulic presses in China is nearly 14 units, including 6 units that have been formed. This number accounts for 27% of the global total. Most of the forging hydraulic presses came out in 2014-2015, and at this time, China has gradually become a major producer of forging hydraulic presses. At this stage, the main features of forging hydraulic press are as follows. 1) The proportion of die forging hydraulic presses and free forging hydraulic presses ranks first in the world. 2) The specifications, quantity, and types of forging hydraulic presses are relatively reasonable. Free forging hydraulic presses are moving towards series development; domestic forging hydraulic presses are gradually improving, which has changed the traditional single die forging situation. 3) The degree of domestic production is further improved. Most of the hydraulic forging presses under construction and completion are imported products. The forging hydraulic press with a weight of 200 MN built by a company is manufactured and designed by foreign countries, and the remaining built forging hydraulic presses are independently produced in China. It shows that the level of domestic design and manufacture of forging hydraulic presses has become the forefront of the world. 4) Free forging hydraulic presses mainly use a push-up cylinder structure and a three-beam and four-column fully prestressed frame; die forging hydraulic presses have many structural types: like a common plate and frame structures, prestressed frame structures, and wire-wound frame structures. 5) The hydraulic system mainly uses an oil control system. Except for the accumulator-type transmission water control system used in the 150MN heavy free forging hydraulic press, the rest use oil pump direct transmission and oil control systems. 6) The medium pressure of the hydraulic system has gradually developed from high pressure to ultra-high pressure, and some have reached 63MPa. 7) The forging force is gradually developing toward the limit, and the largest free forging hydraulic press currently has a scale of over 1000 MN. 8) The degree of mechanization of forging operations is getting higher and higher.

7. Future development of forging hydraulic press

In the 21st century, domestic large-scale forging hydraulic presses have developed rapidly and have made significant progress. Manufacturing and design levels have gradually improved, but there is still a certain gap with developed countries. The main development trends of forging hydraulic presses in the future are as follows. 1) Due to the gradual saturation of the number and specifications of forging hydraulic presses, it will not be suitable for remanufacturing new free forging hydraulic presses in the next few years. This view has been proposed in the relevant report in 2011, and the future free forging process will be the key research object. 2) Look for and expand the die forging market. The number of all hydraulic forging presses has aerospace die forgings as the main target, which far exceeds domestic demand in terms of quantity and forging power, and it is necessary to develop towards the international market. Furthermore, because the type of die forging hydraulic press has obvious gear breaks between 400 and 800 MN, the 600 MN die forging hydraulic press is the main market development target. 3) Pump direct control, flooding and other oil systems have replaced traditional pump accumulator drive and water control systems; ultra-high-pressure systems have become the main trend of future development. 4) The demand for super-large die forging hydraulic presses is gradually increasing. Warm forging performance not only changes the limitation of deformation resistance in traditional cold forging forming but also overcomes the problems of hot forging surface quality and accuracy. Isothermal forging can reasonably apply the high plasticity of metals to obtain corresponding performance and structure. The weight of the built-up presses is less than 200 MN, and the demand for medium and high-end large die forging hydraulic presses is gradually increasing. 5) Large-scale forging hydraulic presses, forging crane linkage control, and manipulators are all automated. At the same time, they are equipped with forging size measuring devices. Strengthening the linkage between manipulators and forging presses can effectively reduce actual labor and continuously improve product quality and efficiency. 6) Reliability is the main standard for measuring the quality of forging machinery in the future. It is mainly the ability of the product to complete the work under the established time and conditions. The main feature is the time quality index of this standard. Multi-directional die forging hydraulic press has gradually become the focus of the development of the die forging hydraulic press industry.

Finally, compared with developed countries, the development of domestic forging hydraulic presses still needs to be improved. With the continuous development of science and technology, the country has increased its investment in basic industrial manufacturing. It is believed that with the continuous efforts of scientific researchers, China will develop into a powerful country for forging hydraulic presses in the future.