YB32-200 Hydraulic Press System
A comprehensive overview of one of the industry's most reliable hydraulic press systems, featuring advanced hydraulic static transmission technology.
Overview
Hydraulic presses are widely used pressure processing equipment in industrial sectors, with the four-column press being the most typical. These machines are commonly used for pressing processes of plastic materials such as stamping, bending, flanging, and sheet drawing. They can also perform straightening, press-fitting, and compression molding processes for powder products. The YB32-200 model incorporates advanced hydraulic static transmission technology to ensure optimal performance.
The hydraulic static transmission system in the YB32-200 press provides the necessary power and control to achieve precise operations. This hydraulic static transmission technology allows for smooth power transfer and efficient operation even under high pressure conditions.
YB32-200 four-column hydraulic press with key components labeled
Basic Requirements for the Hydraulic Press System
1) To complete general pressing processes, the main cylinder (upper hydraulic cylinder) driving the upper slider must implement the working cycle of "rapid downward movement - slow pressurization - pressure holding delay - rapid return - in-place stop".
The ejection cylinder (lower hydraulic cylinder) driving the lower slider must implement the working cycle of "upward ejection - downward return - in-place stop", as shown in Figure 8-7. The hydraulic static transmission system ensures these transitions are smooth and precise.
Figure 8-7: Working cycle diagram of YB32-200 press
2) The pressure in the hydraulic system must be frequently changed and adjusted. To generate large pressing forces to meet work requirements, the system pressure is relatively high, generally in the working pressure range of 10~40MPa. The hydraulic static transmission system is designed to handle these pressure variations efficiently.
The hydraulic static transmission components are specifically engineered to maintain stability across this wide pressure range, ensuring consistent performance and preventing pressure fluctuations that could affect product quality.
3) The hydraulic system has high power, and there is a large difference in speed between the idle stroke and the pressing stroke. Therefore, reasonable power utilization is required.
The hydraulic static transmission technology contributes significantly to energy efficiency by optimizing power distribution based on operational demands. During idle strokes, the hydraulic static transmission system reduces power consumption, while providing maximum power during pressing operations.
4) The hydraulic press is a high-pressure, large-flow system, requiring high working stability and safety.
Safety features integrated into the hydraulic static transmission system include pressure relief valves and overload protection mechanisms. These components work together within the hydraulic static transmission framework to prevent system failures and ensure operator safety.
Working Principle of the Hydraulic System
Figure 8-8 shows the hydraulic system of the YB32-200 press. The hydraulic pump is a constant power variable axial piston pump, which supplies high-pressure oil to the system, and its pressure is regulated by a remote pressure regulating valve. The integration of hydraulic static transmission principles ensures efficient power transfer throughout the system.
Figure 8-8: Hydraulic system diagram of YB32-200 press
1. Rapid Downward Movement of Main Cylinder Piston
When the start button is pressed, the electromagnet 1YA is energized, and the pilot valve and main directional valve are connected to the system in the left position. The main oil circuit is as follows:
Oil inlet path:
Hydraulic pump → sequence valve → main cylinder directional valve → check valve 3 → upper chamber of main cylinder.
Oil return path:
Lower chamber of main cylinder → hydraulically controlled check valve 2 → main cylinder directional valve → lower cylinder directional valve → oil tank.
At this time, the main cylinder piston and the upper slider move down quickly under their own weight. Although the pump has output the maximum flow, the upper chamber of the main cylinder still forms a negative pressure due to insufficient oil, which opens the charging valve 1, and the oil in the charging cylinder is replenished into the upper chamber of the main cylinder. The hydraulic static transmission system efficiently manages this rapid movement phase by adjusting fluid flow rates accordingly.
The hydraulic static transmission technology ensures that even during rapid movements, the system maintains precise control, preventing sudden pressure drops or flow fluctuations that could affect operation smoothness.
2. Slow Pressurization of Main Cylinder Piston
After the upper slider quickly moves down to contact the workpiece, the pressure in the upper chamber of the main cylinder increases, the charging valve 1 closes, and the variable pump automatically reduces the output flow through pressure feedback. At this point, the upper slider switches to slow pressurization. This transition is managed seamlessly by the hydraulic static transmission system, which adjusts to the new pressure requirements.
The hydraulic static transmission components play a crucial role in this phase, ensuring that pressure is applied gradually and evenly. This precision is essential for maintaining product quality, especially in applications requiring consistent pressure distribution across the workpiece surface.
Main cylinder in slow pressurization phase, demonstrating precise pressure control through hydraulic static transmission
3. Main Cylinder Pressure Holding Delay
When the system pressure rises to the set value of the pressure relay, the pressure relay sends a signal to de-energize 1YA, and the pilot valve and main cylinder directional valve return to the neutral position. At this point, the hydraulic pump unloads through the neutral position of the directional valve, and the high-pressure oil in the upper chamber of the main cylinder is closed by the piston seal ring and check valve, being in a pressure-holding state.
The time relay after receiving the electrical signal starts to delay, and the pressure holding delay time can be adjusted within 0~24min. The hydraulic static transmission system maintains stable pressure during this phase, preventing pressure drops that could compromise the forming process.
The efficiency of the hydraulic static transmission system during the pressure holding phase is particularly important for energy conservation. Unlike conventional systems that may continue to consume significant power during holding, the hydraulic static transmission design minimizes energy usage while maintaining precise pressure levels.
4. Rapid Return of Main Cylinder Piston
After the pressure holding delay is completed, the time relay sends a signal to energize 2YA, and the pilot valve and main cylinder directional valve are connected to the system in the right position. The main oil circuit is as follows:
Oil inlet path:
Hydraulic pump → sequence valve → main cylinder directional valve → hydraulically controlled check valve 2 → lower chamber of main cylinder.
Oil return path:
Upper chamber of main cylinder → charging valve 1 (opened by control oil) → oil tank.
At this time, the main cylinder piston drives the upper slider to quickly return. The hydraulic static transmission system facilitates this rapid return by optimizing fluid flow rates and pressure, ensuring efficient operation.
5. Ejection and Return of Ejection Cylinder
When 3YA is energized, the lower cylinder directional valve is in the left position. The oil path is:
Oil inlet path:
Hydraulic pump → sequence valve → main cylinder directional valve (neutral position) → lower cylinder directional valve → lower chamber of ejection cylinder.
Oil return path:
Upper chamber of ejection cylinder → lower cylinder directional valve → oil tank.
The ejection cylinder piston moves upward to eject the workpiece. The hydraulic static transmission system ensures smooth and controlled ejection force, preventing damage to delicate workpieces.
When 4YA is energized, the lower cylinder directional valve is in the right position. The oil path is:
Oil inlet path:
Hydraulic pump → sequence valve → main cylinder directional valve (neutral position) → lower cylinder directional valve → upper chamber of ejection cylinder.
Oil return path:
Lower chamber of ejection cylinder → lower cylinder directional valve → oil tank.
The ejection cylinder piston moves downward to return. The hydraulic static transmission system again demonstrates its versatility by efficiently reversing the fluid direction and adjusting pressure as needed for the return stroke.
Throughout all operational phases, the hydraulic static transmission system maintains optimal energy efficiency by adjusting power output based on real-time demands, significantly reducing overall energy consumption compared to conventional systems.
Main Features of the Hydraulic System
Efficient Power Supply
The system采用 a high-pressure, large-flow constant power variable pump for oil supply, which not only meets process requirements but also saves energy. This is a characteristic feature of the press hydraulic system, leveraging advanced hydraulic static transmission principles.
The hydraulic static transmission technology allows the pump to adjust its output based on demand, preventing energy waste during low-load operations while providing maximum power when needed for pressing operations.
Pressure Control Focus
The hydraulic press is a typical hydraulic system focusing on pressure control. This machine features a pressure regulating circuit controlled by a remote pressure regulating valve, a pressure reducing circuit that makes the control oil circuit obtain a stable low pressure of 2MPa, and a low-pressure (approximately 2.5MPa) unloading circuit for the high-pressure pump.
The hydraulic static transmission system integrates these control mechanisms seamlessly, ensuring precise pressure management across all operational phases.
Gravity-Assisted Movement
This hydraulic press utilizes the self-weight of the upper slider to achieve rapid downward movement and uses a charging valve to charge the upper chamber of the main cylinder. This system structure is simple with few pressed components, commonly used in small and medium-sized hydraulic presses.
The hydraulic static transmission system works in harmony with this gravity-assisted design, providing the necessary control to ensure smooth, controlled movement despite the influence of gravitational forces.
Electro-Hydraulic Directional Valves
Electro-hydraulic directional valves are采用, which are suitable for the requirements of high-pressure and large-flow hydraulic systems. These valves provide reliable switching between different operational phases.
The integration of these valves with the hydraulic static transmission system ensures rapid response times and precise control, even under the high-pressure conditions typical of the YB32-200 press.
Key components of the YB32-200 hydraulic system, including hydraulic static transmission elements
Safety Features
Each of the two hydraulic cylinders in the system has a safety valve for overload protection. The directional valves of the two cylinders are connected in series, which is also a safety measure. These safety features work in conjunction with the hydraulic static transmission system to prevent catastrophic failures.
The hydraulic static transmission system includes multiple layers of protection, including pressure relief mechanisms and flow control devices that prevent system overload. In the event of a pressure spike, the hydraulic static transmission components work in harmony with the safety valves to divert excess pressure, protecting both the equipment and operators.
Additionally, the hydraulic static transmission system incorporates diagnostic capabilities that can detect potential issues before they become serious problems, allowing for preventative maintenance and reducing downtime.
Hydraulic Static Transmission Advantages in This System
The integration of hydraulic static transmission technology in the YB32-200 press offers numerous advantages:
- Improved energy efficiency through variable power output based on demand
- Precise control over pressure and flow rates during all operational phases
- Smooth transitions between different working cycles, reducing mechanical stress
- Enhanced system responsiveness to changing operational requirements
- Reduced maintenance requirements due to optimized component loading
- Consistent performance across a wide range of operating conditions
- Lower noise levels compared to conventional hydraulic systems
These advantages make the hydraulic static transmission-equipped YB32-200 press a reliable and efficient solution for various industrial pressing applications. The hydraulic static transmission technology ensures that the machine can handle the demanding requirements of modern manufacturing processes while maintaining energy efficiency and operational precision.
Conclusion
The YB32-200 hydraulic press represents a sophisticated integration of mechanical and hydraulic technologies, with hydraulic static transmission serving as a core component of its operational efficiency. Its design addresses the key requirements of industrial pressing operations, including precise pressure control, energy efficiency, and operational safety.
The hydraulic static transmission system enables the press to handle the wide range of operational demands, from rapid movement to precise pressure application, with exceptional efficiency. This technology ensures that the YB32-200 remains a versatile and reliable solution for various manufacturing and processing applications.